>From 54243028a84a4c1b915d45fea7540638b1c26c95 Mon Sep 17 00:00:00 2001
From: dickmao <none>
Date: Wed, 16 Jun 2021 13:50:40 -0400
Subject: [PATCH] Major changes to Gnus

Obsolesce gnus-secondary-select-methods for gnus-select-methods.

Rationalize newsrc logic.

Rationalize nnimap.

Obviate `gnus-set-global-variables`, `gnus-summary-local-variables`.

Toggle `gnus-background-get-unread-articles` parallel fetch thread.

* doc/emacs/misc.texi (Gnus Startup): Declutter.
* doc/misc/auth.texi (Multiple GMail accounts with Gnus): Declutter.
* doc/misc/gnus.texi (Finding the News):  Declutter.
(Startup Files): Declutter.
(Startup Variables): Declutter.
(Foreign Groups): Declutter.
(More Threading): Declutter.
(Little Disk Space): Declutter.
* etc/gnus/news-server.ast (User name and password): Whitespace.
* lisp/gnus/gnus-agent.el (gnus): Declutter.
(gnus-cache): Declutter.
(nnvirtual): Declutter.
(gnus-sum): Declutter.
(gnus-score): Declutter.
(gnus-srvr): Declutter.
(gnus-util): Declutter.
(require): Declutter.
(gnus-start): Declutter.
(gnus-all-score-files): Declutter.
(gnus-server-set-status): Declutter.
(gnus-server-named-server): Declutter.
(gnus-inews-do-gcc): Declutter.
(gnus-inews-group-method): Declutter.
(gnus-cache-coding-system): Declutter.
(gnus-agent-read-agentview): Declutter.
* lisp/gnus/gnus-art.el (require): Declutter.
(seq): Declutter.
(gnus-article-wash-types): Buffer-localize.
(gnus-article-image-alist): Buffer-localize.
(gnus-original-group-and-article): Buffer-localize.
(gnus-article-mime-handle-alist): Buffer-localize.
(gnus-article-current-summary): Buffer-localize.
(gnus-article-edit-mode): Declutter.
(gnus-article-mode): Declutter.
(gnus-article-setup-buffer-ensure): Refactor.
(gnus-article-setup-buffer): Refactor.
(gnus-article-prepare): gnus-summary-assume-in-summary, not set-buffer.
(gnus-article-prepare-display): Replace nonsense hook.
(gnus-article-show-summary): Delete gnus-article-set-globals.
(gnus-article-followup-with-original): Whitespace.
(gnus-request-article-this-buffer): Rationalize.
(gnus-flush-original-article-buffer): Consolidate state.
(gnus-article-set-globals): Delete gnus-article-set-globals.
(gnus-article-encrypt-body): Delete gnus-set-global-variables.
* lisp/gnus/gnus-async.el (require): Declutter.
* lisp/gnus/gnus-cache.el (gnus): Declutter.
(gnus-cache-removable-articles): Buffer-localize.
(gnus-cache-read-active): gnus-with-temp-buffer, not gnus-set-work-buffer.
* lisp/gnus/gnus-demon.el (require): Declutter.
* lisp/gnus/gnus-draft.el (gnus): Declutter.
(message): Declutter.
(gnus-cache): Declutter.
* lisp/gnus/gnus-fun.el (gnus-util): Declutter.
* lisp/gnus/gnus-group.el (mm-url): Declutter.
(subr-x): Declutter.
(require): Declutter.
(gnus-group-mode): Elide gnus-update-format-specifications bogus argument.
(gnus-update-group-mark-positions): gnus-with-temp-buffer,
not gnus-set-work-buffer.
(gnus-group-list-groups): Elide gnus-update-format-specifications
bogus argument.
(gnus-group-insert-group-line): Declutter.
(gnus-group-update-eval-form): Declutter.
(gnus-group-first-unread-group): Declutter.
(gnus-group-list-active): Declutter.
(gnus-group-quit): Delete gnus-current-startup-file.
(gnus-group-set-info): Declutter.
* lisp/gnus/gnus-icalendar.el (require): Declutter.
* lisp/gnus/gnus-int.el (gnus-agent-unfetch-articles): Declutter.
(gnus-summary-select-article): Declutter.
(gnus-summary-insert-subject): Declutter.
(gnus-summary-setup-buffer): Declutter.
(gnus-summary-read-group-1): Declutter.
(gnus-server-opened): Declutter.
(gnus-start-news-server): Obsolesce gnus-secondary-select-methods.
(gnus-get-function): Declutter.
(gnus-request-group): Declutter.
(gnus-close-group): Declutter.
* lisp/gnus/gnus-kill.el (gnus-apply-kill-file-internal): prog1 for clarity.
* lisp/gnus/gnus-logic.el (require): Declutter.
(gnus-util): Declutter.
* lisp/gnus/gnus-mlspl.el (gnus-group-split-setup): Rationalize newsrc logic.
* lisp/gnus/gnus-msg.el (require): Declutter.
(gnus): Declutter.
(gnus-util): Declutter.
(cl-extra): Declutter.
(gnus-setup-message): Declutter.
(gnus-inews-add-send-actions): Buffer-localize.
(gnus-group-post-news): gnus-article-copy is better as a variable.
(gnus-copy-article-buffer): Use with-current-buffer instead of set-buffer.
(gnus-msg-preserve-variables): Buffer-local variables need to propagate.
(gnus-msg-inherit-variables): Buffer-local variables need to propagate.
(gnus-post-news): Buffer-local variables need to propagate.
(gnus-post-method): Obsolesce gnus-secondary-select-methods.
(gnus-summary-reply): Whitespace.
* lisp/gnus/gnus-notifications.el (gnus-util): Declutter.
* lisp/gnus/gnus-picon.el (require): Declutter.
* lisp/gnus/gnus-registry.el (gnus-util): Declutter.
(subr-x): Declutter.
(gnus-registry-initialize): Rationalize newsrc logic.
(gnus-registry-unload-hook): Rationalize newsrc logic.
* lisp/gnus/gnus-salt.el (require): Declutter.
(gnus-pick-mode): Elide gnus-update-format-specifications bogus argument.
(gnus-tree-mode): gnus-with-temp-buffer, not gnus-set-work-buffer.
* lisp/gnus/gnus-score.el (gnus-score-alist): Buffer-localize.
(gnus-score-save): Declutter.
(gnus-score-headers): Whitespace.
(gnus-sort-score-files): Declutter.
* lisp/gnus/gnus-search.el (gnus-util): Declutter.
(require): Declutter.
(gnus-search-run-search): nnimap-process-buffer, not nnimap-buffer.
* lisp/gnus/gnus-spec.el (require): Declutter.
(gnus-newsrc-file-version): Buffer-localize.
(gnus-summary-mark-positions): Buffer-localize.
(gnus-update-format-specifications): Elide bogus argument.
(gnus-parse-format): Spaces, not tabs.
(gnus-parse-complex-format): gnus-with-temp-buffer, not gnus-set-work-buffer.
(gnus-parse-simple-format): gnus-with-temp-buffer, not gnus-set-work-buffer.
* lisp/gnus/gnus-srvr.el (require): Declutter.
(gnus-browse-foreign-server): Obsolesce gnus-secondary-select-methods.
* lisp/gnus/gnus-start.el (gnus-util): Declutter.
(nnmail): Declutter.
(gnus-group-decoded-name): Declutter.
(gnus-agent-save-active): Declutter.
(gnus-agentize): Declutter.
(require): Declutter.
(gnus-group-default-level): Declutter.
(gnus-inhibit-demon): Declutter.
(gnus-startup-file): Rationalize newsrc logic.
(gnus-thread-group): Prefix for gnus fetch thread group.
(gnus-backup-startup-file): Rationalize newsrc logic.
(gnus-max-seconds-hold-mutex): Self-explanatory.
(gnus-save-startup-file-via-temp-buffer): Rationalize newsrc logic.
(gnus-mutex-get-unread-articles): Self-explanatory.
(gnus-dot-newsrc): What used to be gnus-startup-file.
(gnus-newsrc-file): What used to be gnus-newsrc-el-file.
(gnus-check-new-newsgroups): Obsolesce gnus-secondary-select-methods.
(gnus-read-newsrc-file): Rationalize newsrc logic.
(gnus-save-newsrc-file): Rationalize newsrc logic.
(gnus-save-dot-newsrc): Rationalize newsrc logic.
(gnus-background-get-unread-articles): Enable backgrounding fetch.
(gnus-read-newsrc-el-hook): Rationalize newsrc logic.
(gnus-read-newsrc-hook): Rationalize newsrc logic.
(gnus-save-newsrc-hook): Rationalize newsrc logic.
(gnus-save-quick-newsrc-hook): Rationalize newsrc logic.
(gnus-save-standard-newsrc-hook): Rationalize newsrc logic.
(gnus-current-startup-file): Rationalize newsrc logic.
(gnus-subscribe-hierarchically): Rationalize newsrc logic.
(gnus-clear-system): Use when instead of and for conditionals.
(gnus-1): Whitespace.
(gnus-dribble-file-name): Rationalize newsrc logic.
(gnus-dribble-read-file): Rationalize newsrc logic.
(gnus-setup-news): Call out a bogus argument.
(gnus-ask-server-for-new-groups): Obsolesce gnus-secondary-select-methods.
(gnus-activate-group): Whitespace.
(gnus-get-unread-articles-in-group): Declutter.
(gnus-scope-globals): Buffer-localize.
(gnus-thread-body): Enable backgrounding fetch.
(gnus-thread-group-running-p): Enable backgrounding fetch.
(gnus-run-thread): Enable backgrounding fetch.
(gnus-chain-arg): Enable backgrounding fetch.
(gnus-time-out-thread): Enable backgrounding fetch.
(gnus-get-unread-articles): Enable backgrounding fetch.
(gnus-method-rank): This became superfluous over the decades.
(gnus-read-active-for-groups): Spaces, not tabs.
(gnus-read-active-file): Obsolesce gnus-secondary-select-methods.
(gnus-read-active-file-1): Declutter.
(gnus-clean-old-newsrc): Rationalize newsrc logic.
(gnus-read-newsrc-el-file): Rationalize newsrc logic.
(gnus-make-newsrc-file): Rationalize newsrc logic.
(gnus-newsrc-to-gnus-format): Declutter.
(gnus-newsrc-parse-options): gnus-with-temp-buffer, not gnus-set-work-buffer.
(defalias): Declutter.
(gnus-gnus-to-quick-newsrc-format): Rationalize newsrc logic.
(gnus-gnus-to-newsrc-format): Rationalize newsrc logic.
(gnus-child-save-newsrc): Rationalize newsrc logic.
(gnus-parent-read-child-newsrc): Rationalize newsrc logic.
(gnus-read-all-descriptions-files): Obsolesce gnus-secondary-select-methods.
* lisp/gnus/gnus-sum.el (gnus-util): Declutter.
(require): Declutter.
(subr-x): Declutter.
(gnus-agent-get-undownloaded-list): Declutter.
(gnus-summary-mark-below): Buffer-localize.
(gnus-summary-expunge-below): Buffer-localize.
(gnus-thread-expunge-below): Buffer-localize.
(gnus-orphan-score): Buffer-localize.
(gnus-article-mime-handles): Buffer-localize.
(gnus-article-decoded-p): Buffer-localize.
(gnus-article-charset): Buffer-localize.
(gnus-scores-exclude-files): Buffer-localize.
(gnus-page-broken): Buffer-localize.
(gnus-original-article): Delete.
(gnus-newsgroup-process-stack): Buffer-localize.
(gnus-sort-gathered-threads-function): Declutter.
(gnus-newsgroup-selected-overlay): Buffer-localize.
(gnus-newsgroup-adaptive-score-file): Buffer-localize.
(gnus-current-score-file): Buffer-localize.
(gnus-newsgroup-display): Buffer-localize.
(gnus-newsgroup-dependencies): Buffer-localize.
(gnus-newsgroup-adaptive): Buffer-localize.
(gnus-summary-highlight-line-function): Buffer-localize.
(gnus-newsgroup-begin): Buffer-localize.
(gnus-newsgroup-end): Buffer-localize.
(gnus-newsgroup-last-rmail): Buffer-localize.
(gnus-newsgroup-last-mail): Buffer-localize.
(gnus-newsgroup-last-folder): Buffer-localize.
(gnus-newsgroup-last-file): Buffer-localize.
(gnus-newsgroup-last-directory): Buffer-localize.
(gnus-newsgroup-auto-expire): Buffer-localize.
(gnus-newsgroup-active): Buffer-localize.
(gnus-newsgroup-highest): Buffer-localize.
(gnus-newsgroup-data): Buffer-localize.
(gnus-newsgroup-data-reverse): Buffer-localize.
(gnus-newsgroup-limit): Buffer-localize.
(gnus-newsgroup-limits): Buffer-localize.
(gnus-summary-use-undownloaded-faces): Buffer-localize.
(gnus-newsgroup-unreads): Buffer-localize.
(gnus-newsgroup-unselected): Buffer-localize.
(gnus-newsgroup-reads): Buffer-localize.
(gnus-newsgroup-expunged-tally): Buffer-localize.
(gnus-newsgroup-marked): Buffer-localize.
(gnus-newsgroup-spam-marked): Buffer-localize.
(gnus-newsgroup-killed): Buffer-localize.
(gnus-newsgroup-cached): Buffer-localize.
(gnus-newsgroup-saved): Buffer-localize.
(gnus-newsgroup-kill-headers): Buffer-localize.
(gnus-newsgroup-replied): Buffer-localize.
(gnus-newsgroup-forwarded): Buffer-localize.
(gnus-newsgroup-expirable): Buffer-localize.
(gnus-newsgroup-processable): Buffer-localize.
(gnus-newsgroup-downloadable): Buffer-localize.
(gnus-newsgroup-unfetched): Buffer-localize.
(gnus-newsgroup-undownloaded): Buffer-localize.
(gnus-newsgroup-unsendable): Buffer-localize.
(gnus-newsgroup-bookmarks): Buffer-localize.
(gnus-newsgroup-dormant): Buffer-localize.
(gnus-newsgroup-unseen): Buffer-localize.
(gnus-newsgroup-seen): Buffer-localize.
(gnus-newsgroup-unexist): Buffer-localize.
(gnus-newsgroup-articles): Buffer-localize.
(gnus-newsgroup-scored): Buffer-localize.
(gnus-newsgroup-headers): Buffer-localize.
(gnus-newsgroup-threads): Buffer-localize.
(gnus-newsgroup-prepared): Buffer-localize.
(gnus-newsgroup-ancient): Buffer-localize.
(gnus-newsgroup-sparse): Buffer-localize.
(gnus-newsgroup-selection): Buffer-localize.
(gnus-current-article): Buffer-localize.
(gnus-article-current): Buffer-localize.
(gnus-current-headers): Buffer-localize.
(gnus-have-all-headers): Buffer-localize.
(gnus-last-article): Buffer-localize.
(gnus-newsgroup-history): Buffer-localize.
(gnus-newsgroup-charset): Buffer-localize.
(gnus-summary-local-variables): Delete.
(gnus-newsgroup-variables): Delete.
(gnus-simplify-subject-fuzzy): gnus-with-temp-buffer, not
gnus-set-work-buffer.
(gnus-summary-mode-group): Delete.
(gnus-summary-mode): Delete gnus-summary-make-local-variables.
(gnus-summary-make-local-variables): Delete.
(gnus-summary-setup-buffer): Buffer-localize.
(gnus-set-global-variables): Delete.
(gnus--dummy-data-list): Rectify ancient type error.
(gnus-update-summary-mark-positions): gnus-summary-assume-in-summary, not
set-buffer.
(gnus-summary-insert-line): Describe the error.
(gnus-summary-read-group-1): Declutter.
(gnus-summary-prepare): Consolidate sorting of message threads.
(gnus-gather-threads-by-references): Declutter.
(gnus-sort-gathered-threads): Consolidate sorting of message threads.
(gnus-summary-assume-in-summary): gnus-summary-assume-in-summary, not
set-buffer.
(gnus-summary-update-article): gnus-summary-assume-in-summary, not
set-buffer.
(gnus-select-newsgroup): Whitespace.
(gnus-summary-display-make-predicate): Declutter.
(gnus-killed-articles): Declutter.
(gnus-set-mode-line): Declutter.
(gnus-get-newsgroup-headers-xover): Buffer-localize.
(gnus-summary-exit): Delete gnus-set-global-variables.
(gnus-handle-ephemeral-exit): Delete gnus-set-global-variables.
(gnus-summary-display-article): Delete gnus-set-global-variables.
(gnus-summary-select-article): gnus-summary-assume-in-summary, not
set-buffer.
(gnus-summary-force-verify-and-decrypt): Spaces, not tabs.
(gnus-summary-next-article): gnus-summary-assume-in-summary, not set-buffer.
(gnus-summary-next-page): Delete gnus-set-global-variables.
(gnus-summary-enter-digest-group): Delete gnus-set-global-variables.
(gnus-summary-edit-article): Delete gnus-set-global-variables.
(gnus-summary-catchup): Whitespace.
(gnus-summary-catchup-and-exit): Spaces, not tabs.
(gnus-summary-sort): Consolidate sorting of message threads.
(gnus-offer-save-summaries): Only do for visible buffers.
* lisp/gnus/gnus-topic.el (require): Declutter.
(gnus-util): Declutter.
(subr-x): Declutter.
(gnus-group-prepare-topics): Elide gnus-update-format-specifications bogus
argument.
* lisp/gnus/gnus-undo.el (gnus-util): Declutter.
* lisp/gnus/gnus-util.el (require): Declutter.
(cl-seq): Declutter.
(gnus-push-end): Push at the end.
(gnus-parent-id): Declutter.
(gnus-buffer-live-p): Clarify.
(gnus-work-buffer): gnus-with-temp-buffer, not gnus-set-work-buffer.
(gnus-delete-duplicates): Delete.
(gnus-assign-former-global): Buffer-localize.
(gnus-with-temp-buffer): gnus-with-temp-buffer, not gnus-set-work-buffer.
* lisp/gnus/gnus-uu.el (require): Declutter.
* lisp/gnus/gnus-win.el (gnus-util): Declutter.
(seq): Declutter.
(gnus-configure-frame): Increase thread safety.
(gnus-configure--frame): Increase thread safety.
(gnus-configure-windows): Declutter.
* lisp/gnus/gnus.el (require): Declutter.
(gnus-util): Declutter.
(seq): Declutter.
(subr-x): Declutter.
(gnus-version-number): Bump version.
(nnheader): Declutter.
(gnus-secondary-select-methods): Obsolesce gnus-secondary-select-methods.
(gnus-select-methods): Obsolesce gnus-secondary-select-methods.
(gnus-select-method): Obsolesce gnus-secondary-select-methods.
(gnus-redefine-select-method-widget): Obsolesce
gnus-secondary-select-methods.
(gnus-original-article-buffer): Buffer-localize.
(gnus-newsgroup-name): Buffer-localize.
(gnus-summary-buffer): Buffer-localize.
(gnus-article-buffer): Buffer-localize.
(gnus-reffed-article-number): Buffer-localize.
(gnus-continuum-version): Bump version.
(gnus-summary-buffer-name): Enable backgrounding fetch.
(gnus-secondary-method-p): Declutter.
(gnus-server-extend-method): Declutter.
(gnus-find-method-for-group): Declutter.
(gnus-read-method): Obsolesce gnus-secondary-select-methods.
(gnus): Declutter.
* lisp/gnus/legacy-gnus-agent.el (gnus-util): Declutter.
* lisp/gnus/message.el (gnus-msg-inherit-variables): Declutter.
(message-pop-to-buffer): Whitespace.
(message-followup): Buffer-local variables need to propagate.
* lisp/gnus/nnfolder.el (gnus-util): Declutter.
* lisp/gnus/nnheader.el (require): Declutter.
(nnheader-init-server-buffer): Refactor.
(nnheader-prep-server-buffer): Refactor.
* lisp/gnus/nnimap.el (require): Declutter.
(gnus-util): Declutter.
(cl-seq): Declutter.
(x-server-version): Declutter.
(nnimap-with-context): Prefer this to set-buffer.
(nnimap-for-process-buffers): Facilitate iteration over nnimap buffers.
(nnimap-connection-alist): Rationalize nnimap.
(nnimap-process-buffers): Rationalize nnimap.
(nnimap--process-buffer-fmt): Rationalize nnimap.
(nnimap-assert-context): Rationalize nnimap.
(nnimap-process-buffer-key): Rationalize nnimap.
(nnimap-group-to-imap): Rationalize nnimap.
(nnimap-buffer): Rationalize nnimap.
(nnimap-process-buffer): Rationalize nnimap.
(nnimap-retrieve-headers): Rationalize nnimap.
(nnimap-open-server): Rationalize nnimap.
(nnimap-make-process-buffer): Rationalize nnimap.
(nnimap-keepalive): Rationalize nnimap.
(nnimap-open-connection): Rationalize nnimap.
(nnimap-open-connection-1): Rationalize nnimap.
(nnimap-close-server): Rationalize nnimap.
(nnimap-server-opened): Rationalize nnimap.
(nnimap-request-article): Rationalize nnimap.
(nnimap-request-head): Rationalize nnimap.
(nnimap-request-articles): Rationalize nnimap.
(nnimap-request-group): Rationalize nnimap.
(nnimap-request-group-scan): Rationalize nnimap.
(nnimap-request-create-group): Rationalize nnimap.
(nnimap-request-delete-group): Rationalize nnimap.
(nnimap-request-rename-group): Rationalize nnimap.
(nnimap-request-expunge-group): Rationalize nnimap.
(nnimap-get-flags): Rationalize nnimap.
(nnimap-close-group): Rationalize nnimap.
(nnimap-request-move-article): Rationalize nnimap.
(nnimap-process-expiry-targets): Rationalize nnimap.
(nnimap-find-expired-articles): Rationalize nnimap.
(nnimap-find-article-by-message-id): Rationalize nnimap.
(nnimap-delete-article): Rationalize nnimap.
(nnimap-request-update-group-status): Rationalize nnimap.
(nnimap-request-set-mark): Rationalize nnimap.
(nnimap-request-accept-article): Rationalize nnimap.
(nnimap-request-list): Rationalize nnimap.
(nnimap-request-newgroups): Rationalize nnimap.
(nnimap-retrieve-group-data-early): Rationalize nnimap.
(nnimap-finish-retrieve-group-infos): Rationalize nnimap.
(nnimap-find-process-buffer): Rationalize nnimap.
(nnimap-get-process-buffer): Rationalize nnimap.
(nnimap-request-thread): Rationalize nnimap.
(nnimap-change-group): Rationalize nnimap.
(nnimap-find-connection): Rationalize nnimap.
(nnimap-wait-for-response): Rationalize nnimap.
(nnimap-split-incoming-mail): Rationalize nnimap.
* lisp/gnus/nnmail.el (gnus-util): Declutter.
(nnmail-cache-primary-mail-backend): Obsolesce gnus-secondary-select-methods.
* lisp/gnus/nnmaildir.el (gnus-util): Declutter.
* lisp/gnus/nntp.el (gnus): Declutter.
(nntp-retrieval-in-progress): Delete.
(nntp-kill-buffer): Declutter.
(nntp-find-connection): Make this defun for easier debugging.
(nntp-find-connection-buffer): Declutter.
(nntp-send-command-and-decode): Declutter.
(nntp-retrieve-group-data-early): Declutter.
(nntp-finish-retrieve-group-infos): Delete nntp-retrieval-in-progress.
(nntp-retrieve-groups): Delete nntp-retrieval-in-progress.
(nntp-make-process-buffer): Delete nntp-retrieval-in-progress.
(nntp-open-connection): Ensure nntp buffers clean up when killed.
* lisp/gnus/nnvirtual.el (gnus): Declutter.
(gnus-util): Declutter.
* lisp/gnus/nnweb.el (require): Declutter.
(gnus-util): Declutter.
* lisp/obsolete/nnir.el (nnimap-buffer): Rationalize nnimap.
(nnimap-process-buffer): Rationalize nnimap.
(nnir-run-imap): Rationalize nnimap.
* lisp/org/ol-gnus.el (gnus-util): Declutter.
* test/src/process-tests.el (process-test-stopped-pipe): Add test.
* test/src/thread-tests.el (eieio): Add test.
(ring): Add test.
(threads-test-channel): Add test.
(threads-test-channel-send): Add test.
(threads-test-channel-recv): Add test.
(threads-signal-early): Add test.
(threads-test-bug33073): Add test.
(threads-test-bug36609-signal): Add test.
(threads-test-glib-lock): Add test.
(threads-test-promiscuous-process): Add test.
---
 doc/emacs/misc.texi                        |    3 +-
 doc/misc/auth.texi                         |   10 +-
 doc/misc/gnus.texi                         |  102 +-
 etc/gnus/news-server.ast                   |    2 +-
 lisp/gnus/gnus-agent.el                    |   18 +-
 lisp/gnus/gnus-art.el                      |  418 ++++---
 lisp/gnus/gnus-async.el                    |    2 -
 lisp/gnus/gnus-cache.el                    |    8 +-
 lisp/gnus/gnus-demon.el                    |    2 -
 lisp/gnus/gnus-draft.el                    |    3 +-
 lisp/gnus/gnus-fun.el                      |    1 -
 lisp/gnus/gnus-group.el                    |  151 +--
 lisp/gnus/gnus-icalendar.el                |    2 -
 lisp/gnus/gnus-int.el                      |  145 +--
 lisp/gnus/gnus-kill.el                     |   96 +-
 lisp/gnus/gnus-logic.el                    |    3 -
 lisp/gnus/gnus-mlspl.el                    |    2 +-
 lisp/gnus/gnus-msg.el                      |  385 ++++---
 lisp/gnus/gnus-notifications.el            |    1 -
 lisp/gnus/gnus-picon.el                    |    2 -
 lisp/gnus/gnus-registry.el                 |    8 +-
 lisp/gnus/gnus-salt.el                     |    7 +-
 lisp/gnus/gnus-score.el                    |   36 +-
 lisp/gnus/gnus-search.el                   |    7 +-
 lisp/gnus/gnus-spec.el                     |   79 +-
 lisp/gnus/gnus-srvr.el                     |   10 +-
 lisp/gnus/gnus-start.el                    | 1171 +++++++++----------
 lisp/gnus/gnus-sum.el                      | 1206 ++++++++------------
 lisp/gnus/gnus-topic.el                    |    8 +-
 lisp/gnus/gnus-undo.el                     |    1 -
 lisp/gnus/gnus-util.el                     |   55 +-
 lisp/gnus/gnus-uu.el                       |    2 -
 lisp/gnus/gnus-win.el                      |   61 +-
 lisp/gnus/gnus.el                          |  166 +--
 lisp/gnus/legacy-gnus-agent.el             |    1 -
 lisp/gnus/message.el                       |    8 +-
 lisp/gnus/nnfolder.el                      |    1 -
 lisp/gnus/nnheader.el                      |   22 +-
 lisp/gnus/nnimap.el                        |  564 ++++-----
 lisp/gnus/nnmail.el                        |    3 +-
 lisp/gnus/nnmaildir.el                     |    1 -
 lisp/gnus/nnrss.el                         |    1 -
 lisp/gnus/nntp.el                          |   85 +-
 lisp/gnus/nnvirtual.el                     |    2 -
 lisp/gnus/nnweb.el                         |    3 -
 lisp/obsolete/nnir.el                      |    6 +-
 lisp/org/ol-gnus.el                        |    1 -
 test/lisp/gnus/gnus-test-select-methods.el |  103 ++
 test/lisp/gnus/gnus-tests.el               |   92 +-
 test/src/process-tests.el                  |    9 +
 test/src/thread-tests.el                   |  118 +-
 51 files changed, 2572 insertions(+), 2621 deletions(-)
 create mode 100644 test/lisp/gnus/gnus-test-select-methods.el

diff --git a/doc/emacs/misc.texi b/doc/emacs/misc.texi
index 027133cc3a..83b0828351 100644
--- a/doc/emacs/misc.texi
+++ b/doc/emacs/misc.texi
@@ -97,8 +97,7 @@ Gnus Startup
   If your system does not have a default news server, or if you wish
 to use Gnus for reading email, then before invoking @kbd{M-x gnus} you
 need to tell Gnus where to get news and/or mail.  To do this,
-customize the variables @code{gnus-select-method} and/or
-@code{gnus-secondary-select-methods}.
+customize the variable @code{gnus-select-methods}.
 @iftex
 See the Gnus manual for details.
 @end iftex
diff --git a/doc/misc/auth.texi b/doc/misc/auth.texi
index 034004d1df..ba6a527752 100644
--- a/doc/misc/auth.texi
+++ b/doc/misc/auth.texi
@@ -280,14 +280,14 @@ Multiple GMail accounts with Gnus
 @chapter Multiple GMail accounts with Gnus
 
 For multiple GMail accounts with Gnus, you have to make two nnimap
-entries in your @code{gnus-secondary-select-methods} with distinct
+entries in your @code{gnus-select-methods} with distinct
 names:
 
 @example
-(setq gnus-secondary-select-methods '((nnimap "gmail"
-                                         (nnimap-address "imap.gmail.com"))
-                                      (nnimap "gmail2"
-                                         (nnimap-address "imap.gmail.com"))))
+(setq gnus-select-methods '((nnimap "gmail"
+                               (nnimap-address "imap.gmail.com"))
+                            (nnimap "gmail2"
+                               (nnimap-address "imap.gmail.com"))))
 @end example
 
 Your netrc entries will then be:
diff --git a/doc/misc/gnus.texi b/doc/misc/gnus.texi
index b63947c044..a59c9bcc1b 100644
--- a/doc/misc/gnus.texi
+++ b/doc/misc/gnus.texi
@@ -1139,13 +1139,13 @@ Finding the News
 you want to get your daily dosage of news from, you'd say:
 
 @lisp
-(setq gnus-select-method '(nntp "news.somewhere.edu"))
+(setq gnus-select-method '((nntp "news.somewhere.edu")))
 @end lisp
 
 If you want to read directly from the local spool, say:
 
 @lisp
-(setq gnus-select-method '(nnspool ""))
+(setq gnus-select-method '((nnspool "")))
 @end lisp
 
 If you can use a local spool, you probably should, as it will almost
@@ -1492,41 +1492,13 @@ Startup Files
 @section Startup Files
 @cindex startup files
 @cindex .newsrc
-@cindex .newsrc.el
 @cindex .newsrc.eld
 
-Most common Unix news readers use a shared startup file called
-@file{.newsrc}.  This file contains all the information about what
-groups are subscribed, and which articles in these groups have been
-read.
+The @file{.newsrc.eld} contains s-exprs persisting Gnus's state.
+Avoid deleting it.
 
-Things got a bit more complicated with @sc{gnus}.  In addition to
-keeping the @file{.newsrc} file updated, it also used a file called
-@file{.newsrc.el} for storing all the information that didn't fit into
-the @file{.newsrc} file.  (Actually, it also duplicated everything in
-the @file{.newsrc} file.)  @sc{gnus} would read whichever one of these
-files was the most recently saved, which enabled people to swap between
-@sc{gnus} and other newsreaders.
-
-That was kinda silly, so Gnus went one better: In addition to the
-@file{.newsrc} and @file{.newsrc.el} files, Gnus also has a file called
-@file{.newsrc.eld}.  It will read whichever of these files that are most
-recent, but it will never write a @file{.newsrc.el} file.  You should
-never delete the @file{.newsrc.eld} file---it contains much information
-not stored in the @file{.newsrc} file.
-
-@vindex gnus-save-newsrc-file
-@vindex gnus-read-newsrc-file
-You can turn off writing the @file{.newsrc} file by setting
-@code{gnus-save-newsrc-file} to @code{nil}, which means you can delete
-the file and save some space, as well as exiting from Gnus faster.
-However, this will make it impossible to use other newsreaders than
-Gnus.  But hey, who would want to, right?  Similarly, setting
-@code{gnus-read-newsrc-file} to @code{nil} makes Gnus ignore the
-@file{.newsrc} file and any @file{.newsrc-SERVER} files, which can be
-convenient if you use a different news reader occasionally, and you
-want to read a different subset of the available groups with that
-news reader.
+The @file{.newsrc} is the standard Usenet rcfile, which Gnus will generally
+ignore unless the @file{.newsrc.eld} did not assign a @code{gnus-newsrc-alist}.
 
 @vindex gnus-save-killed-list
 If @code{gnus-save-killed-list} (default @code{t}) is @code{nil}, Gnus
@@ -1541,34 +1513,8 @@ Startup Files
 saving.  This can be useful in certain obscure situations that involve
 several servers where not all servers support @code{ask-server}.
 
-@vindex gnus-startup-file
-@vindex gnus-backup-startup-file
-@vindex version-control
-The @code{gnus-startup-file} variable says where the startup files are.
-The default value is @file{~/.newsrc}, with the Gnus (El Dingo) startup
-file being whatever that one is, with a @samp{.eld} appended.
-If you want to keep multiple numbered backups of this file, set
-@code{gnus-backup-startup-file}.  It respects the same values as the
-@code{version-control} variable.
-
 @vindex gnus-save-newsrc-hook
-@vindex gnus-save-quick-newsrc-hook
-@vindex gnus-save-standard-newsrc-hook
-@code{gnus-save-newsrc-hook} is called before saving any of the newsrc
-files, while @code{gnus-save-quick-newsrc-hook} is called just before
-saving the @file{.newsrc.eld} file, and
-@code{gnus-save-standard-newsrc-hook} is called just before saving the
-@file{.newsrc} file.  The latter two are commonly used to turn version
-control on or off.  Version control is on by default when saving the
-startup files.  If you want to turn backup creation off, say something like:
-
-@lisp
-(defun turn-off-backup ()
-  (set (make-local-variable 'backup-inhibited) t))
-
-(add-hook 'gnus-save-quick-newsrc-hook 'turn-off-backup)
-(add-hook 'gnus-save-standard-newsrc-hook 'turn-off-backup)
-@end lisp
+@code{gnus-save-newsrc-hook} is called before saving the @file{.newsrc.eld}.
 
 @vindex gnus-init-file
 @vindex gnus-site-init-file
@@ -1687,6 +1633,11 @@ Startup Variables
 
 @table @code
 
+@item gnus-save-dot-newsrc
+If changed to @code{nil} from its default value @code{t}, Gnus will
+stop saving @file{.newsrc}, meaning other newsreaders cannot pick
+up from where Gnus left off.
+
 @item gnus-before-startup-hook
 @vindex gnus-before-startup-hook
 A hook called as the first thing when Gnus is started.
@@ -2646,9 +2597,8 @@ Foreign Groups
 groups under point---@code{gnus-subscribe-newsgroup-method} is not
 consulted.
 
-Changes from the group editing commands are stored in
-@file{~/.newsrc.eld} (@code{gnus-startup-file}).  An alternative is the
-variable @code{gnus-parameters}, @xref{Group Parameters}.
+Changes from the group editing commands are stored in @file{~/.newsrc.eld}.
+An alternative is the variable @code{gnus-parameters}, @xref{Group Parameters}.
 
 @table @kbd
 
@@ -7323,18 +7273,6 @@ More Threading
 This is a number that says how much each sub-thread should be indented.
 The default is 4.
 
-@item gnus-sort-gathered-threads-function
-@vindex gnus-sort-gathered-threads-function
-Sometimes, particularly with mailing lists, the order in which mails
-arrive locally is not necessarily the same as the order in which they
-arrived on the mailing list.  Consequently, when sorting sub-threads
-using the default @code{gnus-thread-sort-by-number}, responses can end
-up appearing before the article to which they are responding to.
-Setting this variable to an alternate value
-(e.g., @code{gnus-thread-sort-by-date}), in a group's parameters or in an
-appropriate hook (e.g., @code{gnus-summary-generate-hook}) can produce a
-more logical sub-thread ordering in such instances.
-
 @end table
 
 
@@ -29693,18 +29631,6 @@ Little Disk Space
 
 @table @code
 
-@item gnus-save-newsrc-file
-If this is @code{nil}, Gnus will never save @file{.newsrc}---it will
-only save @file{.newsrc.eld}.  This means that you will not be able to
-use any other newsreaders than Gnus.  This variable is @code{t} by
-default.
-
-@item gnus-read-newsrc-file
-If this is @code{nil}, Gnus will never read @file{.newsrc}---it will
-only read @file{.newsrc.eld}.  This means that you will not be able to
-use any other newsreaders than Gnus.  This variable is @code{t} by
-default.
-
 @item gnus-save-killed-list
 If this is @code{nil}, Gnus will not save the list of dead groups.  You
 should also set @code{gnus-check-new-newsgroups} to @code{ask-server}
diff --git a/etc/gnus/news-server.ast b/etc/gnus/news-server.ast
index df0bab4519..555ac47cd9 100644
--- a/etc/gnus/news-server.ast
+++ b/etc/gnus/news-server.ast
@@ -20,7 +20,7 @@ Port number: @variable{port}
 
 @node User name and password
 @type interstitial
-@next 
+@next
 (if (assistant-password-required-p)
     "Enter user name and password"
   "Want user name and password?")
diff --git a/lisp/gnus/gnus-agent.el b/lisp/gnus/gnus-agent.el
index cbe3505cd1..2b15ec15dc 100644
--- a/lisp/gnus/gnus-agent.el
+++ b/lisp/gnus/gnus-agent.el
@@ -22,19 +22,19 @@
 
 ;;; Code:
 
-(require 'gnus)
-(require 'gnus-cache)
 (require 'nnmail)
-(require 'nnvirtual)
-(require 'gnus-sum)
-(require 'gnus-score)
-(require 'gnus-srvr)
-(require 'gnus-util)
 (require 'timer)
-(eval-when-compile (require 'cl-lib))
+(require 'gnus-start)
+(require 'gnus-sum)
 
+(autoload 'gnus-all-score-files "gnus-score")
 (autoload 'gnus-server-update-server "gnus-srvr")
+(autoload 'gnus-server-set-status "gnus-srvr")
+(autoload 'gnus-server-named-server "gnus-srvr")
+(autoload 'gnus-inews-do-gcc "gnus-msg")
+(autoload 'gnus-inews-group-method "gnus-msg")
 (autoload 'gnus-agent-customize-category "gnus-cus")
+(defvar gnus-cache-coding-system)
 
 (defcustom gnus-agent-directory (nnheader-concat gnus-directory "agent/")
   "Where the Gnus agent will store its files."
@@ -2063,7 +2063,7 @@ gnus-agent-read-agentview
 	      (let (state sequence uncomp)
 		(while alist
 		  (setq state (caar alist)
-			sequence (inline (gnus-uncompress-range (cdar alist)))
+			sequence (gnus-uncompress-range (cdar alist))
 			alist (cdr alist))
 		  (while sequence
 		    (push (cons (pop sequence) state) uncomp)))
diff --git a/lisp/gnus/gnus-art.el b/lisp/gnus/gnus-art.el
index f2ec9462c5..011bc0902e 100644
--- a/lisp/gnus/gnus-art.el
+++ b/lisp/gnus/gnus-art.el
@@ -24,7 +24,6 @@
 
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
 (defvar tool-bar-map)
 (defvar w3m-minor-mode-map)
 
@@ -41,7 +40,6 @@ w3m-minor-mode-map
 (require 'mm-uu)
 (require 'message)
 (require 'mouse)
-(require 'seq)
 
 (autoload 'gnus-msg-mail "gnus-msg" nil t)
 (autoload 'gnus-button-mailto "gnus-msg")
@@ -1643,9 +1641,10 @@ gnus-english-month-names
     "September" "October" "November" "December"))
 
 (defvar article-goto-body-goes-to-point-min-p nil)
-(defvar gnus-article-wash-types nil)
+(defvar-local gnus-article-wash-types nil)
 (defvar gnus-article-emphasis-alist nil)
-(defvar gnus-article-image-alist nil)
+(defvar-local gnus-original-group-and-article nil)
+(defvar-local gnus-article-image-alist nil)
 
 (defvar gnus-article-mime-handle-alist-1 nil)
 (defvar gnus-treatment-function-alist
@@ -1695,9 +1694,9 @@ gnus-treatment-function-alist
     (gnus-treat-highlight-citation gnus-article-highlight-citation)
     (gnus-treat-body-boundary gnus-article-treat-body-boundary)))
 
-(defvar gnus-article-mime-handle-alist nil)
+(defvar-local gnus-article-mime-handle-alist nil)
 (defvar article-lapsed-timer nil)
-(defvar gnus-article-current-summary nil)
+(defvar-local gnus-article-current-summary nil)
 
 (defvar gnus-article-mode-syntax-table
   (let ((table (copy-syntax-table text-mode-syntax-table)))
@@ -1719,8 +1718,6 @@ gnus-number-of-articles-to-be-saved
 
 (defvar gnus-inhibit-hiding nil)
 
-(defvar gnus-article-edit-mode nil)
-
 ;;; Macros for dealing with the article buffer.
 
 (defmacro gnus-with-article-headers (&rest forms)
@@ -4494,74 +4491,72 @@ gnus-article-mode
   (setq-local nobreak-char-display nil)
   ;; Enable `gnus-article-remove-images' to delete images shr.el renders.
   (setq-local shr-put-image-function #'gnus-shr-put-image)
+  (setq show-trailing-whitespace nil)
   (unless gnus-article-show-cursor
     (setq cursor-in-non-selected-windows nil))
   (gnus-set-default-directory)
   (buffer-disable-undo)
-  (setq show-trailing-whitespace nil)
   (mm-enable-multibyte))
 
+(defun gnus-article-setup-buffer-ensure (summary-buffer
+                                         newsgroup-name
+                                         article-buffer-name
+                                         original-article-buffer-name)
+  "Refactor."
+  (gnus-summary-assume-in-summary
+    (with-current-buffer (gnus-get-buffer-create original-article-buffer-name)
+      (mm-enable-multibyte)
+      (setq major-mode 'gnus-original-article-mode))
+
+    (with-current-buffer (gnus-get-buffer-create article-buffer-name)
+      (dolist (buffer `(,(current-buffer) ,summary-buffer))
+        (gnus-assign-former-global 'gnus-article-buffer
+                                   article-buffer-name
+                                   buffer)
+        (gnus-assign-former-global 'gnus-original-article-buffer
+                                   original-article-buffer-name
+                                   buffer)
+        (gnus-assign-former-global 'gnus-newsgroup-name
+                                   newsgroup-name
+                                   buffer)
+        (gnus-assign-former-global 'gnus-summary-buffer
+                                   summary-buffer
+                                   buffer))
+      (gnus-article-stop-animations)
+      (mm-destroy-parts gnus-article-mime-handles)
+      (setq gnus-article-mime-handles nil
+            gnus-article-mime-handle-alist nil)
+      (unless (derived-mode-p 'gnus-article-mode)
+        (gnus-article-mode))
+      (setq truncate-lines gnus-article-truncate-lines)
+      (gnus-summary-set-local-parameters newsgroup-name)
+      (when article-lapsed-timer
+        (gnus-stop-date-timer))
+      (when gnus-article-update-date-headers
+        (gnus-start-date-timer gnus-article-update-date-headers))
+      (current-buffer))))
+
 (defun gnus-article-setup-buffer ()
   "Initialize the article buffer."
-  (let* ((name (if gnus-single-article-buffer "*Article*"
-		 (concat "*Article " gnus-newsgroup-name "*")))
-	 (original
-	  (progn (string-match "\\*Article" name)
-		 (concat " *Original Article"
-			 (substring name (match-end 0))))))
-    (setq gnus-article-buffer name)
-    (setq gnus-original-article-buffer original)
-    (setq gnus-article-mime-handle-alist nil)
-    (with-current-buffer gnus-summary-buffer
-      ;; This might be a variable local to the summary buffer.
-      (unless gnus-single-article-buffer
-	(setq gnus-article-buffer name)
-	(setq gnus-original-article-buffer original)
-	(gnus-set-global-variables)))
+  (gnus-summary-assume-in-summary
     (gnus-article-setup-highlight-words)
-    ;; Init original article buffer.
-    (with-current-buffer (gnus-get-buffer-create gnus-original-article-buffer)
-      (mm-enable-multibyte)
-      (setq major-mode 'gnus-original-article-mode)
-      (make-local-variable 'gnus-original-article))
-    (if (and (get-buffer name)
-	     (with-current-buffer name
-	       (if gnus-article-edit-mode
-		   (if (y-or-n-p "Article mode edit in progress; discard? ")
-		       (progn
-			 (set-buffer-modified-p nil)
-			 (gnus-kill-buffer name)
-			 (message "")
-			 nil)
-		     (error "Action aborted"))
-		 t)))
-	(let ((summary gnus-summary-buffer))
-	  (with-current-buffer name
-            (setq-local gnus-article-edit-mode nil)
-	    (gnus-article-stop-animations)
-	    (when gnus-article-mime-handles
-	      (mm-destroy-parts gnus-article-mime-handles)
-	      (setq gnus-article-mime-handles nil))
-	    ;; Set it to nil in article-buffer!
-	    (setq gnus-article-mime-handle-alist nil)
-	    (buffer-disable-undo)
-	    (setq buffer-read-only t)
-	    (unless (derived-mode-p 'gnus-article-mode)
-	      (gnus-article-mode))
-            (setq-local gnus-summary-buffer summary)
-	    (setq truncate-lines gnus-article-truncate-lines)
-	    (current-buffer)))
-      (let ((summary gnus-summary-buffer))
-	(with-current-buffer (gnus-get-buffer-create name)
-	  (gnus-article-mode)
-	  (setq truncate-lines gnus-article-truncate-lines)
-          (setq-local gnus-summary-buffer summary)
-	  (gnus-summary-set-local-parameters gnus-newsgroup-name)
-	  (when article-lapsed-timer
-	    (gnus-stop-date-timer))
-	  (when gnus-article-update-date-headers
-	    (gnus-start-date-timer gnus-article-update-date-headers))
-	  (current-buffer))))))
+    (let* ((summary gnus-summary-buffer)
+           (group gnus-newsgroup-name)
+           (name (if gnus-single-article-buffer "*Article*"
+                   (concat "*Article " group "*")))
+           (original (progn (string-match "\\*Article" name)
+                            (concat " *Original Article"
+                                    (substring name (match-end 0))))))
+      (when-let ((existing-buffer (get-buffer name)))
+        (with-current-buffer existing-buffer
+          (when (eq major-mode 'gnus-article-edit-mode)
+            (if (y-or-n-p "Article mode edit in progress; discard? ")
+                (progn
+                  (set-buffer-modified-p nil)
+                  (gnus-kill-buffer existing-buffer)
+                  (message ""))
+              (error "Action aborted")))))
+      (gnus-article-setup-buffer-ensure summary group name original))))
 
 (defun gnus-article-stop-animations ()
   (cancel-function-timers 'image-animate-timeout))
@@ -4593,113 +4588,116 @@ gnus-article-prepare
 ARTICLE should either be an article number or a Message-ID.
 If ARTICLE is an id, HEADER should be the article headers.
 If ALL-HEADERS is non-nil, no headers are hidden."
-  (save-excursion                ;FIXME: Shouldn't that be save-current-buffer?
-    ;; Make sure we start in a summary buffer.
-    (unless (derived-mode-p 'gnus-summary-mode)
-      (set-buffer gnus-summary-buffer))
-    (setq gnus-summary-buffer (current-buffer))
-    (let* ((summary-buffer (current-buffer))
-	   (gnus-tmp-internal-hook gnus-article-internal-prepare-hook)
-	   (group gnus-newsgroup-name)
-	   result)
-      (save-excursion
-	(gnus-article-setup-buffer)
-	(set-buffer gnus-article-buffer)
-	;; Deactivate active regions.
-	(when transient-mark-mode
-	  (setq mark-active nil))
-	(if (not (setq result (let ((inhibit-read-only t))
-				(gnus-request-article-this-buffer
-				 article group))))
-	    ;; There is no such article.
-	    (save-excursion
-	      (when (and (numberp article)
-			 (not (memq article gnus-newsgroup-sparse)))
-		(setq gnus-article-current
-		      (cons gnus-newsgroup-name article))
-		(set-buffer gnus-summary-buffer)
-		(setq gnus-current-article article)
-		(if (and (memq article gnus-newsgroup-undownloaded)
-			 (not (gnus-online (gnus-find-method-for-group
-					    gnus-newsgroup-name))))
-		    (progn
-		      (gnus-summary-set-agent-mark article)
-		      (message "Message marked for downloading"))
-		  (gnus-summary-mark-article article gnus-canceled-mark)
-		  (unless (memq article gnus-newsgroup-sparse)
-		    (gnus-error 1 "No such article (may have expired or been canceled)")))))
-	  (if (or (eq result 'pseudo)
-		  (eq result 'nneething))
-	      (progn
-		(with-current-buffer summary-buffer
-		  (push article gnus-newsgroup-history)
-		  (setq gnus-last-article gnus-current-article
-			gnus-current-article 0
-			gnus-current-headers nil
-			gnus-article-current nil)
-		  (if (eq result 'nneething)
-		      (gnus-configure-windows 'summary)
-		    (gnus-configure-windows 'article))
-		  (gnus-set-global-variables))
-		(let ((gnus-article-mime-handle-alist-1
-		       gnus-article-mime-handle-alist))
-		  (gnus-set-mode-line 'article)))
-	    ;; The result from the `request' was an actual article -
-	    ;; or at least some text that is now displayed in the
-	    ;; article buffer.
-	    (when (and (numberp article)
-		       (not (eq article gnus-current-article)))
-	      ;; Seems like a new article has been selected.
-	      ;; `gnus-current-article' must be an article number.
-	      (with-current-buffer summary-buffer
-		(push article gnus-newsgroup-history)
-		(setq gnus-last-article gnus-current-article
-		      gnus-current-article article
-		      gnus-current-headers
-		      (gnus-summary-article-header gnus-current-article)
-		      gnus-article-current
-		      (cons gnus-newsgroup-name gnus-current-article))
-		(unless (mail-header-p gnus-current-headers)
-		  (setq gnus-current-headers nil))
-		(gnus-summary-goto-subject gnus-current-article)
-		(when (gnus-summary-show-thread)
-		  ;; If the summary buffer really was folded, the
-		  ;; previous goto may not actually have gone to
-		  ;; the right article, but the thread root instead.
-		  ;; So we go again.
-		  (gnus-summary-goto-subject gnus-current-article))
-		(gnus-run-hooks 'gnus-mark-article-hook)
-		(gnus-set-mode-line 'summary)
-		(when (gnus-visual-p 'article-highlight 'highlight)
-		  (gnus-run-hooks 'gnus-visual-mark-article-hook))
-		;; Set the global newsgroup variables here.
-		(gnus-set-global-variables)
-		(setq gnus-have-all-headers
-		      (or all-headers gnus-show-all-headers))))
-	    (save-excursion
-	      (gnus-configure-windows 'article))
-	    (when (or (numberp article)
-		      (stringp article))
-	      (gnus-article-prepare-display)
-	      ;; Do page break.
-	      (goto-char (point-min))
-	      (when gnus-break-pages
-		(gnus-narrow-to-page)))
-	    (let ((gnus-article-mime-handle-alist-1
-		   gnus-article-mime-handle-alist))
-	      (gnus-set-mode-line 'article))
-	    (article-goto-body)
-	    (unless (bobp)
-	      (forward-line -1))
-	    (set-window-point (get-buffer-window (current-buffer)) (point))
-	    (gnus-configure-windows 'article)
-	    ;; Make sure the article begins with the top of the header.
-	    (let ((window (get-buffer-window gnus-article-buffer)))
-	      (when window
-		(with-current-buffer (window-buffer window)
-		  (set-window-point window (point-min)))))
-	    (gnus-run-hooks 'gnus-article-prepare-hook)
-	    t))))))
+  (gnus-summary-assume-in-summary
+    (gnus-article-setup-buffer)
+    (let ((group gnus-newsgroup-name)
+          (summary (current-buffer))
+          result)
+      (with-current-buffer gnus-article-buffer
+        ;; Deactivate active regions.
+        (when transient-mark-mode
+          (setq mark-active nil))
+        (cond ((not (setq result (let ((inhibit-read-only t))
+                                   (gnus-request-article-this-buffer
+                                    article group))))
+               (with-current-buffer summary
+                 (when (and (numberp article)
+                            (not (memq article gnus-newsgroup-sparse)))
+                   (setq gnus-article-current
+                         (cons gnus-newsgroup-name article))
+                   (setq gnus-current-article article)
+                   (if (and (memq article gnus-newsgroup-undownloaded)
+                            (not (gnus-online (gnus-find-method-for-group
+                                               gnus-newsgroup-name))))
+                       (progn
+                         (gnus-summary-set-agent-mark article)
+                         (message "Message marked for downloading"))
+                     (gnus-summary-mark-article article gnus-canceled-mark)
+                     (unless (memq article gnus-newsgroup-sparse)
+                       (gnus-error
+                        1
+                        "No such article (may have expired or been canceled)"))))))
+              ((or (eq result 'pseudo) (eq result 'nneething))
+               (with-current-buffer summary
+                 (push article gnus-newsgroup-history)
+                 (setq gnus-last-article gnus-current-article
+                       gnus-current-article 0
+                       gnus-current-headers nil
+                       gnus-article-current nil)
+                 (if (eq result 'nneething)
+                     (gnus-configure-windows 'summary)
+                   (gnus-configure-windows 'article)))
+               (let ((gnus-article-mime-handle-alist-1
+                      gnus-article-mime-handle-alist))
+                 (gnus-set-mode-line 'article)))
+              ;; The result from the `request' was an actual article -
+              ;; or at least some text that is now displayed in the
+              ;; article buffer.
+              (t
+               (with-current-buffer summary
+                 (when (and (numberp article)
+                            (not (eq article gnus-current-article)))
+                   ;; Seems like a new article has been selected.
+                   ;; `gnus-current-article' must be an article number.
+                   (push article gnus-newsgroup-history)
+                   ;; TODO: a more elegant way to replicate former globals
+                   (dolist (buffer `(,(get-buffer gnus-article-buffer)
+                                     ,(get-buffer summary)))
+                     (gnus-assign-former-global
+                      'gnus-last-article
+                      gnus-current-article
+                      buffer)
+                     (gnus-assign-former-global
+                      'gnus-current-article
+                      article
+                      buffer)
+                     (gnus-assign-former-global
+                      'gnus-current-headers
+                      (gnus-summary-article-header article)
+                      buffer)
+                     (gnus-assign-former-global
+                      'gnus-article-current
+                      (cons gnus-newsgroup-name article)
+                      buffer))
+                   (unless (mail-header-p gnus-current-headers)
+                     (setq gnus-current-headers nil))
+                   (gnus-summary-goto-subject gnus-current-article)
+                   (when (gnus-summary-show-thread)
+                     ;; If the summary buffer really was folded, the
+                     ;; previous goto may not actually have gone to
+                     ;; the right article, but the thread root instead.
+                     ;; So we go again.
+                     (gnus-summary-goto-subject gnus-current-article))
+                   (gnus-run-hooks 'gnus-mark-article-hook)
+                   (gnus-set-mode-line 'summary)
+                   (when (gnus-visual-p 'article-highlight 'highlight)
+                     (gnus-run-hooks 'gnus-visual-mark-article-hook))
+                   (setq gnus-have-all-headers
+                         (or all-headers gnus-show-all-headers))))
+               (save-excursion
+                 (gnus-configure-windows 'article))
+               (when (or (numberp article)
+                         (stringp article))
+                 (gnus-article-prepare-display)
+                 ;; Do page break.
+                 (goto-char (point-min))
+                 (when gnus-break-pages
+                   (gnus-narrow-to-page)))
+               (let ((gnus-article-mime-handle-alist-1
+                      gnus-article-mime-handle-alist))
+                 (gnus-set-mode-line 'article))
+               (article-goto-body)
+               (unless (bobp)
+                 (forward-line -1))
+               (set-window-point (get-buffer-window (current-buffer)) (point))
+               (gnus-configure-windows 'article)
+               ;; Make sure the article begins with the top of the header.
+               (let ((window (get-buffer-window gnus-article-buffer)))
+                 (when window
+                   (with-current-buffer (window-buffer window)
+                     (set-window-point window (point-min)))))
+               (gnus-run-hooks 'gnus-article-prepare-hook)
+               t))))))
 
 ;;;###autoload
 (defun gnus-article-prepare-display ()
@@ -4714,7 +4712,7 @@ gnus-article-prepare-display
     (setq buffer-read-only nil
 	  gnus-article-wash-types nil
 	  gnus-article-image-alist nil)
-    (gnus-run-hooks 'gnus-tmp-internal-hook)
+    (gnus-run-hooks 'gnus-article-internal-prepare-hook)
     (when gnus-display-mime-function
       (funcall gnus-display-mime-function))
     ;; Add attachment buttons to the header.
@@ -6683,7 +6681,6 @@ gnus-article-show-summary
   (interactive nil gnus-article-mode)
   (if (not (gnus-buffer-live-p gnus-summary-buffer))
       (error "There is no summary buffer for this article buffer")
-    (gnus-article-set-globals)
     (gnus-configure-windows 'article)
     (gnus-summary-goto-subject gnus-current-article)
     (gnus-summary-position-point)))
@@ -6960,16 +6957,16 @@ gnus-article-followup-with-original
   (interactive nil gnus-article-mode)
   (let ((article (cdr gnus-article-current))
 	contents)
-      (if (not (and transient-mark-mode mark-active))
-	  (with-current-buffer gnus-summary-buffer
-	    (gnus-summary-followup (list (list article))))
-	(setq contents (buffer-substring (point) (mark t)))
-	;; Deactivate active regions.
-	(when transient-mark-mode
-	  (setq mark-active nil))
-	(with-current-buffer gnus-summary-buffer
-	  (gnus-summary-followup
-	   (list (list article contents)))))))
+    (if (not (and transient-mark-mode mark-active))
+        (with-current-buffer gnus-summary-buffer
+          (gnus-summary-followup (list (list article))))
+      (setq contents (buffer-substring (point) (mark t)))
+      ;; Deactivate active regions.
+      (when transient-mark-mode
+        (setq mark-active nil))
+      (with-current-buffer gnus-summary-buffer
+        (gnus-summary-followup
+         (list (list article contents)))))))
 
 (defun gnus-article-hide (&optional arg force)
   "Hide all the gruft in the current article.
@@ -7059,8 +7056,10 @@ gnus-request-article-this-buffer
 	   ((and (get-buffer gnus-original-article-buffer)
 		 (numberp article)
 		 (with-current-buffer gnus-original-article-buffer
-		   (and (equal (car gnus-original-article) group)
-			(eq (cdr gnus-original-article) article))))
+                   (when (consp gnus-original-group-and-article)
+                     (cl-destructuring-bind (ogroup . oarticle)
+                         gnus-original-group-and-article
+                       (and (equal ogroup group) (eq oarticle article))))))
             (insert-buffer-substring gnus-original-article-buffer)
 	    'article)
 	   ;; Check the backlog.
@@ -7131,24 +7130,23 @@ gnus-request-article-this-buffer
       ;; Take the article from the original article buffer
       ;; and place it in the buffer it's supposed to be in.
       (when (and (get-buffer gnus-article-buffer)
-		 (equal (buffer-name (current-buffer))
-			(buffer-name (get-buffer gnus-article-buffer))))
-	(save-excursion
-	  (if (get-buffer gnus-original-article-buffer)
-	      (set-buffer gnus-original-article-buffer)
-	    (set-buffer (gnus-get-buffer-create gnus-original-article-buffer))
-	    (buffer-disable-undo)
-	    (setq major-mode 'gnus-original-article-mode)
-	    (setq buffer-read-only t))
-	  (let ((inhibit-read-only t))
-	    (erase-buffer)
-	    (insert-buffer-substring gnus-article-buffer))
-	  (setq gnus-original-article (cons group article)))
-
-	;; Decode charsets.
-	(run-hooks 'gnus-article-decode-hook)
-	;; Mark article as decoded or not.
-	(setq gnus-article-decoded-p gnus-article-decode-hook))
+                 (equal (buffer-name (current-buffer))
+                        (buffer-name (get-buffer gnus-article-buffer))))
+        (unless (get-buffer gnus-original-article-buffer)
+          (with-current-buffer (gnus-get-buffer-create gnus-original-article-buffer)
+            (buffer-disable-undo)
+            (setq major-mode 'gnus-original-article-mode)
+            (setq buffer-read-only t)))
+        (let ((article-buffer gnus-article-buffer))
+          (with-current-buffer (get-buffer gnus-original-article-buffer)
+            (let ((inhibit-read-only t))
+              (erase-buffer)
+              (insert-buffer-substring article-buffer))
+            (setq gnus-original-group-and-article (cons group article))))
+        ;; Decode charsets.
+        (run-hooks 'gnus-article-decode-hook)
+        ;; Mark article as decoded or not.
+        (setq gnus-article-decoded-p gnus-article-decode-hook))
 
       ;; Update sparse articles.
       (when (and do-update-line
@@ -7261,7 +7259,6 @@ gnus-article-edit-mode
   (make-local-variable 'gnus-prev-winconf)
   (setq-local font-lock-defaults '(message-font-lock-keywords t))
   (setq-local mail-header-separator "")
-  (setq-local gnus-article-edit-mode t)
   (mml-mode)
   (setq buffer-read-only nil)
   (buffer-enable-undo)
@@ -7335,7 +7332,7 @@ gnus-article-edit-done
 (defun gnus-flush-original-article-buffer ()
   (when (get-buffer gnus-original-article-buffer)
     (with-current-buffer gnus-original-article-buffer
-      (setq gnus-original-article nil))))
+      (setq gnus-original-group-and-article nil))))
 
 (defun gnus-article-edit-exit ()
   "Exit the article editing without updating."
@@ -8134,10 +8131,6 @@ gnus-article-copy-string
 
 ;;; Internal functions:
 
-(defun gnus-article-set-globals ()
-  (with-current-buffer gnus-summary-buffer
-    (gnus-set-global-variables)))
-
 (defun gnus-signature-toggle (end)
   (gnus-with-article-buffer
     (let ((inhibit-point-motion-hooks t))
@@ -8628,7 +8621,6 @@ gnus-article-encrypt-body
 	      (mail-parse-ignored-charsets gnus-newsgroup-ignored-charsets)
 	      (summary-buffer gnus-summary-buffer)
 	      references point)
-	  (gnus-set-global-variables)
 	  (when (gnus-group-read-only-p)
 	    (error "The current newsgroup does not support article encrypt"))
 	  (gnus-summary-show-article t)
diff --git a/lisp/gnus/gnus-async.el b/lisp/gnus/gnus-async.el
index fefd02c7bf..239e5f67bd 100644
--- a/lisp/gnus/gnus-async.el
+++ b/lisp/gnus/gnus-async.el
@@ -24,8 +24,6 @@
 
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
-
 (require 'gnus)
 (require 'gnus-sum)
 (require 'nntp)
diff --git a/lisp/gnus/gnus-cache.el b/lisp/gnus/gnus-cache.el
index 34dba54c11..33fcfd8931 100644
--- a/lisp/gnus/gnus-cache.el
+++ b/lisp/gnus/gnus-cache.el
@@ -24,9 +24,6 @@
 
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
-
-(require 'gnus)
 (require 'gnus-sum)
 
 (declare-function gnus-agent-load-alist "gnus-agent" (group))
@@ -81,7 +78,7 @@ gnus-cache-coding-system
 
 ;;; Internal variables.
 
-(defvar gnus-cache-removable-articles nil)
+(defvar-local gnus-cache-removable-articles nil)
 (defvar gnus-cache-buffer nil)
 (defvar gnus-cache-active-hashtb nil)
 (defvar gnus-cache-active-altered nil)
@@ -630,8 +627,7 @@ gnus-cache-read-active
       ;; There is no active file, so we generate one.
       (gnus-cache-generate-active)
     ;; We simply read the active file.
-    (save-excursion
-      (gnus-set-work-buffer)
+    (gnus-with-temp-buffer
       (nnheader-insert-file-contents gnus-cache-active-file)
       (gnus-active-to-gnus-format
        nil (setq gnus-cache-active-hashtb
diff --git a/lisp/gnus/gnus-demon.el b/lisp/gnus/gnus-demon.el
index e99247c0ca..bcc70654b0 100644
--- a/lisp/gnus/gnus-demon.el
+++ b/lisp/gnus/gnus-demon.el
@@ -24,8 +24,6 @@
 
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
-
 (require 'gnus)
 (require 'gnus-int)
 (require 'nnheader)
diff --git a/lisp/gnus/gnus-draft.el b/lisp/gnus/gnus-draft.el
index 9a0f21359f..6d2c2fd57a 100644
--- a/lisp/gnus/gnus-draft.el
+++ b/lisp/gnus/gnus-draft.el
@@ -24,12 +24,11 @@
 
 ;;; Code:
 
-(require 'gnus)
 (require 'gnus-sum)
-(require 'message)
 (require 'gnus-msg)
 (require 'nndraft)
 (require 'gnus-agent)
+(require 'gnus-cache)
 
 ;;; Draft minor mode
 
diff --git a/lisp/gnus/gnus-fun.el b/lisp/gnus/gnus-fun.el
index 8bca4ffe38..923aa1ec38 100644
--- a/lisp/gnus/gnus-fun.el
+++ b/lisp/gnus/gnus-fun.el
@@ -25,7 +25,6 @@
 ;;; Code:
 
 (require 'mm-util)
-(require 'gnus-util)
 (require 'gnus)
 
 (defvar gnus-face-properties-alist)
diff --git a/lisp/gnus/gnus-group.el b/lisp/gnus/gnus-group.el
index c8b95d9185..bedbf19ea2 100644
--- a/lisp/gnus/gnus-group.el
+++ b/lisp/gnus/gnus-group.el
@@ -35,10 +35,10 @@
 (require 'gnus-undo)
 (require 'gmm-utils)
 (require 'time-date)
+(require 'mm-url)
+(require 'subr-x)
 
 (eval-when-compile
-  (require 'mm-url)
-  (require 'subr-x)
   (with-suppressed-warnings ((lexical features))
     (dlet ((features (cons 'gnus-group features)))
       (require 'gnus-sum))))
@@ -1136,7 +1136,7 @@ gnus-group-mode
   (setq truncate-lines t)
   (setq show-trailing-whitespace nil)
   (gnus-set-default-directory)
-  (gnus-update-format-specifications nil 'group 'group-mode)
+  (gnus-update-format-specifications 'group 'group-mode)
   (gnus-update-group-mark-positions)
   (when gnus-use-undo
     (gnus-undo-mode 1))
@@ -1144,19 +1144,17 @@ gnus-group-mode
     (gnus-child-mode)))
 
 (defun gnus-update-group-mark-positions ()
-  (save-excursion
-    (let ((gnus-process-mark ?\200)
-	  (gnus-group-update-hook nil)
-	  (gnus-group-marked '("dummy.group"))
-	  (gnus-active-hashtb (gnus-make-hashtable 10)))
-      (gnus-set-active "dummy.group" '(0 . 0))
-      (gnus-set-work-buffer)
-      (gnus-group-insert-group-line "dummy.group" 0 nil 0 nil)
-      (goto-char (point-min))
+  (let ((gnus-process-mark ?\200)
+	(gnus-group-update-hook nil)
+	(gnus-group-marked '("dummy.group"))
+	(gnus-active-hashtb (gnus-make-hashtable 10)))
+    (gnus-set-active "dummy.group" '(0 . 0))
+    (gnus-with-temp-buffer
+      (save-excursion
+        (gnus-group-insert-group-line "dummy.group" 0 nil 0 nil))
       (setq gnus-group-mark-positions
-	    (list (cons 'process (and (search-forward
-				       (string gnus-process-mark) nil t)
-				      (- (point) (point-min) 1))))))))
+	    (list (cons 'process (when (search-forward (string gnus-process-mark) nil t)
+				   (- (point) (point-min) 1))))))))
 
 (defun gnus-mouse-pick-group (e)
   "Enter the group under the mouse pointer."
@@ -1248,27 +1246,19 @@ gnus-group-list-groups
 	  unread (cdr gnus-group-list-mode)))
   (setq level (gnus-group-default-level level))
   (gnus-group-setup-buffer)
-  (gnus-update-format-specifications nil 'group 'group-mode)
-  (let ((case-fold-search nil)
-	(props (text-properties-at (point-at-bol)))
-	(empty (= (point-min) (point-max)))
+  (gnus-update-format-specifications 'group 'group-mode)
+  (let ((props (text-properties-at (point-at-bol)))
 	(group (gnus-group-group-name))
-	number)
-    (set-buffer gnus-group-buffer)
-    (setq number (funcall gnus-group-prepare-function level unread lowest))
+        (number (funcall gnus-group-prepare-function level unread lowest))
+        case-fold-search)
     (when (or (and (numberp number)
 		   (zerop number))
 	      (zerop (buffer-size)))
-      ;; No groups in the buffer.
       (gnus-message 5 "%s" gnus-no-groups-message))
-    ;; We have some groups displayed.
-    (goto-char (point-max))
     (when (or (not gnus-group-goto-next-group-function)
 	      (not (funcall gnus-group-goto-next-group-function
 			    group props)))
       (cond
-       (empty
-	(goto-char (point-min)))
        ((not group)
 	;; Go to the first group with unread articles.
 	(gnus-group-search-forward t))
@@ -1277,8 +1267,7 @@ gnus-group-list-groups
 	;; has disappeared in the new listing, try to find the next
 	;; one.  If no next one can be found, just leave point at the
 	;; first newsgroup in the buffer.
-	(when (not (gnus-text-property-search
-		    'gnus-group group nil 'goto))
+	(unless (gnus-text-property-search 'gnus-group group nil 'goto)
 	  (let ((groups (cdr-safe (member group gnus-group-list))))
 	    (while (and groups
 			(not (gnus-text-property-search
@@ -1287,7 +1276,8 @@ gnus-group-list-groups
 	    (unless groups
 	      (goto-char (point-max))
 	      (forward-line -1)))))))
-    ;; Adjust cursor point.
+    (when (eobp)
+      (goto-char (point-min)))
     (gnus-group-position-point)))
 
 (defun gnus-group-list-level (level &optional all)
@@ -1590,7 +1580,7 @@ gnus-group-insert-group-line
     (setq end (point))
     (gnus-group--setup-tool-bar-update beg end)
     (forward-line -1)
-    (when (inline (gnus-visual-p 'group-highlight 'highlight))
+    (when (gnus-visual-p 'group-highlight 'highlight)
       (gnus-group-highlight-line gnus-tmp-group beg end))
     (gnus-run-hooks 'gnus-group-update-hook)
     (forward-line)))
@@ -1615,8 +1605,7 @@ gnus-group-update-eval-form
     (let* ((entry (gnus-group-entry group))
            (active (gnus-active group))
            (info (nth 1 entry))
-           (method (inline (gnus-server-get-method
-			    group (gnus-info-method info))))
+           (method (gnus-server-get-method group (gnus-info-method info)))
            (marked (gnus-info-marks info))
 	   (env
 	    (list
@@ -2725,17 +2714,13 @@ gnus-group-best-unread-group
 (defun gnus-group-first-unread-group ()
   "Go to the first group with unread articles."
   (interactive nil gnus-group-mode)
-  (prog1
-      (let ((opoint (point))
-	    unread)
-	(goto-char (point-min))
-	(if (or (eq (setq unread (gnus-group-group-unread)) t) ; Not active.
-		(and (numberp unread)	; Not a topic.
-		     (not (zerop unread))) ; Has unread articles.
-		(zerop (gnus-group-next-unread-group 1))) ; Next unread group.
-	    (point)			; Success.
-	  (goto-char opoint)
-	  nil))				; Not success.
+  (let ((opoint (point)))
+    (goto-char (save-excursion
+                 (goto-char (point-min))
+                 (let ((unread (gnus-group-group-unread)))
+                   (cond ((and (numberp unread) (not (zerop unread)))
+	                  (point))
+	                 (t opoint)))))
     (gnus-group-position-point)))
 
 (defun gnus-group-enter-server-mode ()
@@ -4137,7 +4122,7 @@ gnus-group-list-active
 			 "\n"))
        (list 'gnus-group group
 	     'gnus-unread t
-	     'gnus-level (inline (gnus-group-level group)))))
+	     'gnus-level (gnus-group-level group))))
     (goto-char (point-min))))
 
 (defun gnus-activate-all-groups (level)
@@ -4167,17 +4152,13 @@ gnus-group-get-new-news
     (unless gnus-child
       (gnus-parent-read-child-newsrc))
 
-    (gnus-get-unread-articles (gnus-group-default-level arg t)
-			      nil one-level)
+    (gnus-get-unread-articles arg nil one-level)
 
     ;; If the user wants it, we scan for new groups.
     (when (eq gnus-check-new-newsgroups 'always)
       (gnus-find-new-newsgroups))
 
-    (gnus-check-reasonable-setup)
-    (gnus-run-hooks 'gnus-after-getting-new-news-hook)
-    (gnus-group-list-groups (and (numberp arg)
-				 (max (car gnus-group-list-mode) arg)))))
+    (gnus-check-reasonable-setup)))
 
 (defun gnus-group-get-new-news-this-group (&optional n dont-scan)
   "Check for newly arrived news in the current group (and the N-1 next groups).
@@ -4493,10 +4474,9 @@ gnus-group-quit
 	    (zerop (buffer-size))
 	    (not (gnus-server-opened gnus-select-method))
 	    gnus-expert-user
-	    (not gnus-current-startup-file)
 	    (gnus-yes-or-no-p
 	     (format "Quit reading news without saving %s? "
-		     (file-name-nondirectory gnus-current-startup-file))))
+		     (file-name-nondirectory gnus-newsrc-file))))
     (gnus-run-hooks 'gnus-exit-gnus-hook)
     (gnus-configure-windows 'group t)
     (when (and (gnus-buffer-live-p gnus-dribble-buffer)
@@ -4551,8 +4531,7 @@ gnus-group-set-info
     (let* ((entry (gnus-group-entry
 		   (or method-only-group (gnus-info-group info))))
 	   (part-info info)
-	   (info (if method-only-group (nth 1 entry) info))
-	   method)
+	   (info (if method-only-group (nth 1 entry) info)))
       (when method-only-group
 	(unless entry
 	  (error "Trying to change non-existent group %s" method-only-group))
@@ -4569,45 +4548,35 @@ gnus-group-set-info
       (unless entry
 	;; This is a new group, so we just create it.
 	(with-current-buffer gnus-group-buffer
-	  (setq method (gnus-info-method info))
-	  (when (gnus-server-equal method "native")
-	    (setq method nil))
-	  (with-current-buffer gnus-group-buffer
-	    (if method
-		;; It's a foreign group...
+          (let ((method (gnus-info-method info)))
+	    (with-current-buffer gnus-group-buffer
+	      (if (gnus-server-equal method "native")
+                  (gnus-group-make-group (gnus-info-group info))
 		(gnus-group-make-group
 		 (gnus-group-real-name (gnus-info-group info))
-		 (if (stringp method) method
+		 (if (stringp method)
+                     method
 		   (prin1-to-string (car method)))
-		 (and (consp method)
-		      (nth 1 (gnus-info-method info)))
-		 nil)
-	      ;; It's a native group.
-	      (gnus-group-make-group (gnus-info-group info) nil nil nil)))
-	  (gnus-message 6 "Note: New group created")
-	  (setq entry
-		(gnus-group-entry (gnus-group-prefixed-name
-				   (gnus-group-real-name (gnus-info-group info))
-				   (or (gnus-info-method info) gnus-select-method))))))
-      ;; Whether it was a new group or not, we now have the entry, so we
-      ;; can do the update.
-      (if entry
-	  (progn
-	    (setcar (nthcdr 1 entry) info)
-	    (when (and (not (eq (car entry) t))
-		       (gnus-active (gnus-info-group info)))
-	      (setcar entry (length
-			     (gnus-list-of-unread-articles (car info)))))
-	    ;; The above `setcar' will only affect the hashtable, not
-	    ;; the alist: update the alist separately, but only if
-	    ;; it's been initialized.
-	    (when gnus-newsrc-alist
-	      (push info (cdr (setq gnus-newsrc-alist
-				    (remove (assoc-string
-					     (gnus-info-group info)
-					     gnus-newsrc-alist)
-					    gnus-newsrc-alist))))))
-	(error "No such group: %s" (gnus-info-group info))))))
+		 (when (consp method)
+		   (nth 1 (gnus-info-method info))))))
+	    (setq entry
+	          (gnus-group-entry (gnus-group-prefixed-name
+				     (gnus-group-real-name (gnus-info-group info))
+				     (or method gnus-select-method))))
+	    (gnus-message 6 "Note: New group created"))))
+      (setcar (nthcdr 1 entry) info)
+      (when (and (not (eq (car entry) t))
+		 (gnus-active (gnus-info-group info)))
+	(setcar entry (length
+		       (gnus-list-of-unread-articles (car info)))))
+      ;; How `gnus-newsrc-hashtb' and `gnus-newsrc-alist' are
+      ;; dutifully kept in-sync is anyone's guess...
+      (when gnus-newsrc-alist
+	(push info (cdr (setq gnus-newsrc-alist
+			      (remove (assoc-string
+				       (gnus-info-group info)
+				       gnus-newsrc-alist)
+				      gnus-newsrc-alist))))))))
 
 ;; Ad-hoc function for inserting data from a different newsrc.eld
 ;; file.  Use with caution, if at all.
diff --git a/lisp/gnus/gnus-icalendar.el b/lisp/gnus/gnus-icalendar.el
index 1b2743c148..855cc630a0 100644
--- a/lisp/gnus/gnus-icalendar.el
+++ b/lisp/gnus/gnus-icalendar.el
@@ -42,8 +42,6 @@
 (require 'gnus-sum)
 (require 'gnus-art)
 
-(eval-when-compile (require 'cl-lib))
-
 (defun gnus-icalendar-find-if (pred seq)
   (catch 'found
     (while seq
diff --git a/lisp/gnus/gnus-int.el b/lisp/gnus/gnus-int.el
index 01053797b3..e71be0518f 100644
--- a/lisp/gnus/gnus-int.el
+++ b/lisp/gnus/gnus-int.el
@@ -33,6 +33,11 @@
 (autoload 'gnus-agent-regenerate-group "gnus-agent")
 (autoload 'gnus-agent-read-servers-validate-native "gnus-agent")
 (autoload 'gnus-agent-possibly-synchronize-flags-server "gnus-agent")
+(autoload 'gnus-agent-unfetch-articles "gnus-agent")
+(autoload 'gnus-summary-select-article "gnus-sum")
+(autoload 'gnus-summary-insert-subject "gnus-sum")
+(autoload 'gnus-summary-setup-buffer "gnus-sum")
+(autoload 'gnus-summary-read-group-1 "gnus-sum")
 
 (defcustom gnus-open-server-hook nil
   "Hook called just before opening connection to the news server."
@@ -84,7 +89,7 @@ gnus-server-opened
            (if (stringp command-method)
                (gnus-server-to-method command-method)
              command-method)))
-      (funcall (inline (gnus-get-function gnus-command-method 'server-opened))
+      (funcall (gnus-get-function gnus-command-method 'server-opened)
                (nth 1 gnus-command-method)))))
 
 (defun gnus-status-message (command-method)
@@ -105,73 +110,69 @@ gnus-status-message
 (defun gnus-start-news-server (&optional confirm)
   "Open a method for getting news.
 If CONFIRM is non-nil, the user will be asked for an NNTP server."
-  (let (how)
-    (if gnus-current-select-method
-	;; Stream is already opened.
-	nil
-      ;; Open NNTP server.
-      (when confirm
-	;; Read server name with completion.
-	(setq gnus-nntp-server
-	      (gnus-completing-read "NNTP server"
-                                    (cons gnus-nntp-server
-					  (if (boundp 'gnus-secondary-servers)
-					      gnus-secondary-servers))
-                                    nil gnus-nntp-server)))
-
-      (when (and gnus-nntp-server
-		 (stringp gnus-nntp-server)
-		 (not (string= gnus-nntp-server "")))
-	(setq gnus-select-method
-	      (cond ((or (string= gnus-nntp-server "")
-			 (string= gnus-nntp-server "::"))
-		     (list 'nnspool (system-name)))
-		    ((string-match "^:" gnus-nntp-server)
-		     (list 'nnmh gnus-nntp-server
-			   (list 'nnmh-directory
-				 (file-name-as-directory
-				  (expand-file-name
-				   (substring gnus-nntp-server 1) "~/")))
-			   (list 'nnmh-get-new-mail nil)))
-		    (t
-		     (list 'nntp gnus-nntp-server)))))
-
-      (setq how (car gnus-select-method))
-      (cond
-       ((eq how 'nnspool)
-	(require 'nnspool)
-	(gnus-message 5 "Looking up local news spool..."))
-       ((eq how 'nnmh)
-	(require 'nnmh)
-	(gnus-message 5 "Looking up mh spool..."))
-       (t
-	(require 'nntp)))
-      (setq gnus-current-select-method gnus-select-method)
-      (gnus-run-hooks 'gnus-open-server-hook)
+  (unless gnus-current-select-method
+    (when confirm
+      ;; Read server name with completion.
+      (setq gnus-nntp-server
+            (gnus-completing-read "NNTP server"
+                                  (cons gnus-nntp-server
+                                        (if (boundp 'gnus-secondary-servers)
+                                            gnus-secondary-servers))
+                                  nil gnus-nntp-server)))
+    (when (and (stringp gnus-nntp-server)
+               (not (zerop (length gnus-nntp-server))))
+      ;; this will also assign the obsolete variable `gnus-select-method'
+      (custom-set-variables
+       `(gnus-select-methods
+         (quote (,(cond ((string= gnus-nntp-server "::")
+                         (list 'nnspool (system-name)))
+                        ((string-match "^:" gnus-nntp-server)
+                         (list 'nnmh gnus-nntp-server
+                               (list 'nnmh-directory
+                                     (file-name-as-directory
+                                      (expand-file-name
+                                       (substring gnus-nntp-server 1) "~/")))
+                               (list 'nnmh-get-new-mail nil)))
+                        (t
+                         (list 'nntp gnus-nntp-server))))))))
+    (setq gnus-current-select-method gnus-select-method)
+    (cl-case (car gnus-select-method)
+      ('nnspool
+       (require 'nnspool)
+       (gnus-message 5 "Looking up local news spool..."))
+      ('nnmh
+       (require 'nnmh)
+       (gnus-message 5 "Looking up mh spool..."))
+      (t
+       (require 'nntp)))
+    (gnus-run-hooks 'gnus-open-server-hook)
+
+    ;; Partially validate agent covered methods now that the
+    ;; gnus-select-method is known.
+
+    (if gnus-agent
+        ;; NOTE: This is here for one purpose only.  By validating
+        ;; the current select method, it converts the old 5.10.3,
+        ;; and earlier, format to the current format.  That enables
+        ;; the agent code within gnus-open-server to function
+        ;; correctly.
+        (gnus-agent-read-servers-validate-native gnus-select-method))
 
-      ;; Partially validate agent covered methods now that the
-      ;; gnus-select-method is known.
-
-      (if gnus-agent
-          ;; NOTE: This is here for one purpose only.  By validating
-          ;; the current select method, it converts the old 5.10.3,
-          ;; and earlier, format to the current format.  That enables
-          ;; the agent code within gnus-open-server to function
-          ;; correctly.
-          (gnus-agent-read-servers-validate-native gnus-select-method))
-
-      (or
-       ;; gnus-open-server-hook might have opened it
-       (gnus-server-opened gnus-select-method)
-       (gnus-open-server gnus-select-method)
-       gnus-batch-mode
-       (gnus-y-or-n-p
-	(format-message
-	 "%s (%s) open error: `%s'.  Continue? "
-	 (car gnus-select-method) (cadr gnus-select-method)
-	 (gnus-status-message gnus-select-method)))
-       (gnus-error 1 "Couldn't open server on %s"
-		   (nth 1 gnus-select-method))))))
+    (or
+     ;; gnus-open-server-hook might have opened it
+     (gnus-server-opened gnus-select-method)
+     (gnus-open-server gnus-select-method)
+     gnus-batch-mode
+     (gnus-y-or-n-p
+      (format-message
+       "%s (%s) open error%s.  Continue? "
+       (car gnus-select-method) (cadr gnus-select-method)
+       (if-let ((status (gnus-status-message gnus-select-method))
+                (status* (not (zerop (length status)))))
+           (format ": `%s'" status)
+         "")))
+     (gnus-error 1 "Couldn't open server on %s"
+                 (nth 1 gnus-select-method)))))
 
 (defun gnus-check-group (group)
   "Try to make sure that the server where GROUP exists is alive."
@@ -219,7 +220,7 @@ gnus-get-function
     (setq method (gnus-server-to-method method)))
   ;; Check cache of constructed names.
   (let* ((method-sym (if gnus-agent
-			 (inline (gnus-agent-get-function method))
+			 (gnus-agent-get-function method)
 		       (car method)))
 	 (method-fns (get method-sym 'gnus-method-functions))
 	 (func (let ((method-fnlist-elt (assq function method-fns)))
@@ -488,11 +489,11 @@ gnus-request-compact
 (defun gnus-request-group (group &optional dont-check command-method info)
   "Request GROUP.  If DONT-CHECK, no information is required."
   (let ((gnus-command-method
-	 (or command-method (inline (gnus-find-method-for-group group)))))
+	 (or command-method (gnus-find-method-for-group group))))
     (when (stringp gnus-command-method)
       (setq gnus-command-method
-	    (inline (gnus-server-to-method gnus-command-method))))
-    (funcall (inline (gnus-get-function gnus-command-method 'request-group))
+	    (gnus-server-to-method gnus-command-method)))
+    (funcall (gnus-get-function gnus-command-method 'request-group)
 	     (gnus-group-real-name group) (nth 1 gnus-command-method)
 	     dont-check
 	     info)))
@@ -515,7 +516,7 @@ gnus-request-group-scan
 
 (defun gnus-close-group (group)
   "Request the GROUP be closed."
-  (let ((gnus-command-method (inline (gnus-find-method-for-group group))))
+  (let ((gnus-command-method (gnus-find-method-for-group group)))
     (funcall (gnus-get-function gnus-command-method 'close-group)
 	     (gnus-group-real-name group) (nth 1 gnus-command-method))))
 
diff --git a/lisp/gnus/gnus-kill.el b/lisp/gnus/gnus-kill.el
index f73627a648..4a480dde66 100644
--- a/lisp/gnus/gnus-kill.el
+++ b/lisp/gnus/gnus-kill.el
@@ -333,60 +333,48 @@ gnus-apply-kill-file-unless-scored
 (defun gnus-apply-kill-file-internal ()
   "Apply a kill file to the current newsgroup.
 Returns the number of articles marked as read."
-  (let* ((kill-files (list (gnus-newsgroup-kill-file nil)
-			   (gnus-newsgroup-kill-file gnus-newsgroup-name)))
-	 (unreads (length gnus-newsgroup-unreads))
-	 (gnus-summary-inhibit-highlight t)
-	 ) ;; beg
-    (setq gnus-newsgroup-kill-headers nil)
-    ;; If there are any previously scored articles, we remove these
-    ;; from the `gnus-newsgroup-headers' list that the score functions
-    ;; will see.  This is probably pretty wasteful when it comes to
-    ;; conses, but is, I think, faster than having to assq in every
-    ;; single score function.
-    (let ((files kill-files))
-      (while files
-	(if (file-exists-p (car files))
-	    (let ((headers gnus-newsgroup-headers))
-	      (if gnus-kill-killed
-		  (setq gnus-newsgroup-kill-headers
-			(mapcar #'mail-header-number headers))
-		(while headers
-		  (unless (gnus-member-of-range
-			   (mail-header-number (car headers))
-			   gnus-newsgroup-killed)
-		    (push (mail-header-number (car headers))
-			  gnus-newsgroup-kill-headers))
-		  (setq headers (cdr headers))))
-	      (setq files nil))
-	  (setq files (cdr files)))))
-    (if (not gnus-newsgroup-kill-headers)
-	()
-      (save-window-excursion
-	(save-excursion
-	  (while kill-files
-	    (if (not (file-exists-p (car kill-files)))
-		()
-	      (gnus-message 6 "Processing kill file %s..." (car kill-files))
-	      (find-file (car kill-files))
-	      (goto-char (point-min))
-
-	      (if (consp (ignore-errors (read (current-buffer))))
-		  (gnus-kill-parse-gnus-kill-file)
-		(gnus-kill-parse-rn-kill-file))
-
-	      (gnus-message
-	       6 "Processing kill file %s...done" (car kill-files)))
-	    (setq kill-files (cdr kill-files)))))
-
-      (gnus-set-mode-line 'summary)
-
-      (if nil ;; beg
-	  (let ((nunreads (- unreads (length gnus-newsgroup-unreads))))
-	    (or (eq nunreads 0)
-		(gnus-message 6 "Marked %d articles as read" nunreads))
-	    nunreads)
-	0))))
+  (prog1 0
+    (let ((kill-files (list (gnus-newsgroup-kill-file nil)
+			    (gnus-newsgroup-kill-file gnus-newsgroup-name)))
+	  (gnus-summary-inhibit-highlight t))
+      (setq gnus-newsgroup-kill-headers nil)
+      ;; If there are any previously scored articles, we remove these
+      ;; from the `gnus-newsgroup-headers' list that the score functions
+      ;; will see.  This is probably pretty wasteful when it comes to
+      ;; conses, but is, I think, faster than having to assq in every
+      ;; single score function.
+      (let ((files kill-files))
+        (while files
+	  (if (file-exists-p (car files))
+	      (let ((headers gnus-newsgroup-headers))
+	        (if gnus-kill-killed
+		    (setq gnus-newsgroup-kill-headers
+			  (mapcar #'mail-header-number headers))
+		  (while headers
+		    (unless (gnus-member-of-range
+			     (mail-header-number (car headers))
+			     gnus-newsgroup-killed)
+		      (push (mail-header-number (car headers))
+			    gnus-newsgroup-kill-headers))
+		    (setq headers (cdr headers))))
+	        (setq files nil))
+	    (setq files (cdr files)))))
+      (unless gnus-newsgroup-kill-headers
+        (save-window-excursion
+	  (save-excursion
+	    (dolist (file kill-files)
+	      (unless (file-exists-p file)
+	        (gnus-message 6 "Processing kill file %s..." file)
+                (when-let ((buf (find-file-noselect file)))
+                  (unwind-protect
+                      (with-current-buffer buf
+	                (if (consp (ignore-errors (read (current-buffer))))
+		            (gnus-kill-parse-gnus-kill-file)
+		          (gnus-kill-parse-rn-kill-file))
+	                (gnus-message 6 "Processing kill file %s...done" file))
+                    (let (kill-buffer-query-functions)
+                      (kill-buffer buf))))))))
+        (gnus-set-mode-line 'summary)))))
 
 ;; Parse a Gnus killfile.
 (defun gnus-kill-parse-gnus-kill-file ()
diff --git a/lisp/gnus/gnus-logic.el b/lisp/gnus/gnus-logic.el
index cdfdc9b731..261cabfb04 100644
--- a/lisp/gnus/gnus-logic.el
+++ b/lisp/gnus/gnus-logic.el
@@ -24,11 +24,8 @@
 
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
-
 (require 'gnus)
 (require 'gnus-score)
-(require 'gnus-util)
 
 ;;; Internal variables.
 
diff --git a/lisp/gnus/gnus-mlspl.el b/lisp/gnus/gnus-mlspl.el
index d42f097125..34840b1906 100644
--- a/lisp/gnus/gnus-mlspl.el
+++ b/lisp/gnus/gnus-mlspl.el
@@ -70,7 +70,7 @@ gnus-group-split-setup
      ;; Split updating requires `gnus-newsrc-hashtb' to be
      ;; initialized; the read newsrc hook is the only hook that comes
      ;; after initialization, but before checking for new news.
-     'gnus-read-newsrc-el-hook)
+     'gnus-read-newsrc-hook)
    #'gnus-group-split-update))
 
 ;;;###autoload
diff --git a/lisp/gnus/gnus-msg.el b/lisp/gnus/gnus-msg.el
index bac987e2f0..87c775a44a 100644
--- a/lisp/gnus/gnus-msg.el
+++ b/lisp/gnus/gnus-msg.el
@@ -25,12 +25,9 @@
 
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
-
-(require 'gnus)
 (require 'message)
 (require 'gnus-art)
-(require 'gnus-util)
+(require 'cl-extra)
 
 (defcustom gnus-post-method 'current
   "Preferred method for posting USENET news.
@@ -398,90 +395,83 @@ gnus-inews-make-draft
 (defvar gnus-article-reply nil)
 (defmacro gnus-setup-message (config &rest forms)
   (declare (indent 1) (debug t))
-  (let ((winconf (make-symbol "gnus-setup-message-winconf"))
-	(winconf-name (make-symbol "gnus-setup-message-winconf-name"))
-	(buffer (make-symbol "gnus-setup-message-buffer"))
-	(article (make-symbol "gnus-setup-message-article"))
-	(oarticle (make-symbol "gnus-setup-message-oarticle"))
-	(yanked (make-symbol "gnus-setup-yanked-articles"))
-	(group (make-symbol "gnus-setup-message-group")))
-    `(let ((,winconf (current-window-configuration))
-	   (,winconf-name gnus-current-window-configuration)
-	   (,buffer (buffer-name (current-buffer)))
-	   (,article   (when gnus-article-reply
-			 (or (nnselect-article-number
-			      (or (car-safe gnus-article-reply)
-				  gnus-article-reply))
-			     gnus-article-reply)))
-	   (,oarticle gnus-article-reply)
-	   (,yanked gnus-article-yanked-articles)
-           (,group (if gnus-article-reply
-		       (or (nnselect-article-group
-			    (or (car-safe gnus-article-reply)
-			        gnus-article-reply))
-                           gnus-newsgroup-name)
-                     gnus-newsgroup-name))
-	   (message-header-setup-hook
-	    (copy-sequence message-header-setup-hook))
-	   (mbl mml-buffer-list)
-	   (message-mode-hook (copy-sequence message-mode-hook)))
-       (setq mml-buffer-list nil)
-       (add-hook 'message-header-setup-hook (lambda ()
-					      (gnus-inews-insert-gcc ,group)))
-       ;; message-newsreader and message-mailer were formerly set in
-       ;; gnus-inews-add-send-actions, but this is too late when
-       ;; message-generate-headers-first is used. --ansel
-       (add-hook 'message-mode-hook
-		 (lambda nil
-		   (setq message-newsreader
-			 (setq message-mailer (gnus-extended-version)))))
-       ;; #### FIXME: for a reason that I did not manage to identify yet,
-       ;; the variable `gnus-newsgroup-name' does not honor a dynamically
-       ;; scoped or setq'ed value from a caller like `C-u gnus-summary-mail'.
-       ;; After evaluation of @forms below, it gets the value we actually want
-       ;; to override, and the posting styles are used. For that reason, I've
-       ;; added an optional argument to `gnus-configure-posting-styles' to
-       ;; make sure that the correct value for the group name is used. -- drv
-       (add-hook 'message-mode-hook
-		 (if (memq ,config '(reply-yank reply))
-		     (lambda ()
-		       (gnus-configure-posting-styles ,group))
+  `(let ((setup-winconf (current-window-configuration))
+	 (setup-winconf-name gnus-current-window-configuration)
+	 (setup-buffer (buffer-name (current-buffer)))
+	 (setup-article (when gnus-article-reply
+			  (or (nnselect-article-number
+			       (or (car-safe gnus-article-reply)
+				   gnus-article-reply))
+			      gnus-article-reply)))
+	 (setup-oarticle gnus-article-reply)
+	 (setup-yanked gnus-article-yanked-articles)
+         (setup-group (if gnus-article-reply
+			  (or (nnselect-article-group
+			       (or (car-safe gnus-article-reply)
+			           gnus-article-reply))
+			      gnus-newsgroup-name)
+			gnus-newsgroup-name))
+	 (message-header-setup-hook
+	  (copy-sequence message-header-setup-hook))
+	 (mbl mml-buffer-list)
+	 (message-mode-hook (copy-sequence message-mode-hook)))
+     (setq mml-buffer-list nil)
+     (add-hook 'message-header-setup-hook (lambda ()
+					    (gnus-inews-insert-gcc setup-group)))
+     ;; message-newsreader and message-mailer were formerly set in
+     ;; gnus-inews-add-send-actions, but this is too late when
+     ;; message-generate-headers-first is used. --ansel
+     (add-hook 'message-mode-hook
+	       (lambda nil
+		 (setq message-newsreader
+		       (setq message-mailer (gnus-extended-version)))))
+     ;; #### FIXME: for a reason that I did not manage to identify yet,
+     ;; the variable `gnus-newsgroup-name' does not honor a dynamically
+     ;; scoped or setq'ed value from a caller like `C-u gnus-summary-mail'.
+     ;; After evaluation of @forms below, it gets the value we actually want
+     ;; to override, and the posting styles are used. For that reason, I've
+     ;; added an optional argument to `gnus-configure-posting-styles' to
+     ;; make sure that the correct value for the group name is used. -- drv
+     (add-hook 'message-mode-hook
+	       (if (memq ,config '(reply-yank reply))
 		   (lambda ()
-		     ;; There may be an old " *gnus article copy*" buffer.
-		     (let (gnus-article-copy)
-		       (gnus-configure-posting-styles ,group)))))
-       (gnus-alist-pull ',(intern gnus-draft-meta-information-header)
-		  message-required-headers)
-       (when (and ,group
-		  (not (string= ,group "")))
-	 (push (cons
-		(intern gnus-draft-meta-information-header)
-		(gnus-inews-make-draft (or ,yanked ,article)))
-	       message-required-headers))
-       (unwind-protect
-	   (progn
-	     ,@forms)
-	 (gnus-inews-add-send-actions ,winconf ,buffer ,oarticle ,config
-				      ,yanked ,winconf-name)
-	 (setq gnus-message-buffer (current-buffer))
-         (setq-local gnus-message-group-art (cons ,group ,article))
-         ;; Enable highlighting of different citation levels
-         (when gnus-message-highlight-citation
-           (gnus-message-citation-mode 1))
-         (gnus-run-hooks 'gnus-message-setup-hook)
-         (if (eq major-mode 'message-mode)
-             (let ((mbl1 mml-buffer-list))
-               (setq mml-buffer-list mbl)  ;; Global value
-               (setq-local mml-buffer-list mbl1) ;; Local value
-               (add-hook 'change-major-mode-hook #'mml-destroy-buffers nil t)
-               (add-hook 'kill-buffer-hook #'mml-destroy-buffers t t))
-           (mml-destroy-buffers)
-           (setq mml-buffer-list mbl)))
-       (message-hide-headers)
-       (gnus-add-buffer)
-       (gnus-configure-windows ,config t)
-       (run-hooks 'post-command-hook)
-       (set-buffer-modified-p nil))))
+		     (gnus-configure-posting-styles setup-group))
+		 (lambda ()
+		   ;; There may be an old " *gnus article copy*" buffer.
+		   (let (gnus-article-copy)
+		     (gnus-configure-posting-styles setup-group)))))
+     (gnus-alist-pull ',(intern gnus-draft-meta-information-header)
+		      message-required-headers)
+     (when (and setup-group
+		(not (string= setup-group "")))
+       (push (cons
+	      (intern gnus-draft-meta-information-header)
+	      (gnus-inews-make-draft (or setup-yanked setup-article)))
+	     message-required-headers))
+     (unwind-protect
+	 (progn
+	   ,@forms)
+       (gnus-inews-add-send-actions setup-winconf setup-buffer setup-oarticle ,config
+				    setup-yanked setup-winconf-name)
+       (setq gnus-message-buffer (current-buffer))
+       (setq-local gnus-message-group-art (cons setup-group setup-article))
+       ;; Enable highlighting of different citation levels
+       (when gnus-message-highlight-citation
+         (gnus-message-citation-mode 1))
+       (gnus-run-hooks 'gnus-message-setup-hook)
+       (if (eq major-mode 'message-mode)
+           (let ((mbl1 mml-buffer-list))
+             (setq mml-buffer-list mbl)  ;; Global value
+             (setq-local mml-buffer-list mbl1) ;; Local value
+             (add-hook 'change-major-mode-hook #'mml-destroy-buffers nil t)
+             (add-hook 'kill-buffer-hook #'mml-destroy-buffers t t))
+         (mml-destroy-buffers)
+         (setq mml-buffer-list mbl)))
+     (message-hide-headers)
+     (gnus-add-buffer)
+     (gnus-configure-windows ,config t)
+     (run-hooks 'post-command-hook)
+     (set-buffer-modified-p nil)))
 
 (defun gnus-inews-make-draft-meta-information (group articles)
   (when (numberp articles)
@@ -577,8 +567,8 @@ gnus-inews-add-send-actions
   (when gnus-agent
     (add-hook 'message-header-hook #'gnus-agent-possibly-save-gcc nil t))
   (setq message-post-method
-	(let ((gn gnus-newsgroup-name))
-	  (lambda (&optional arg) (gnus-post-method arg gn))))
+        `(lambda (&optional arg)
+           (gnus-post-method arg ,(buffer-local-value 'gnus-newsgroup-name (get-buffer buffer)))))
   (message-add-action
    `(progn
       (setq gnus-current-window-configuration ',winconf-name)
@@ -661,7 +651,7 @@ gnus-group-post-news
 	       (or (gnus-group-group-name) ""))
 	   ""))
 	;; make sure last viewed article doesn't affect posting styles:
-	(gnus-article-copy))
+	gnus-article-copy)
     (gnus-post-news 'post gnus-newsgroup-name nil nil nil nil
 		    (string= gnus-newsgroup-name ""))))
 
@@ -869,58 +859,85 @@ gnus-copy-article-buffer
     (mm-enable-multibyte))
   (let ((article-buffer (or article-buffer gnus-article-buffer))
 	end beg)
-    (if (not (gnus-buffer-live-p article-buffer))
-	(error "Can't find any article buffer")
-      (with-current-buffer article-buffer
-	(let ((gnus-newsgroup-charset (or gnus-article-charset
-					  gnus-newsgroup-charset))
-	      (inhibit-read-only t)
-	      (gnus-newsgroup-ignored-charsets
-	       (or gnus-article-ignored-charsets
-		   gnus-newsgroup-ignored-charsets)))
-	  (save-restriction
-	    ;; Copy over the (displayed) article buffer, delete
-	    ;; hidden text and remove text properties.
-	    (widen)
-	    (copy-to-buffer gnus-article-copy (point-min) (point-max))
-	    (set-buffer gnus-article-copy)
-	    (when yank-string
-	      (message-goto-body)
-	      (delete-region (point) (point-max))
-	      (insert yank-string))
-	    (gnus-article-delete-text-of-type 'annotation)
-	    (gnus-article-delete-text-of-type 'multipart)
-	    (gnus-remove-text-with-property 'gnus-prev)
-	    (gnus-remove-text-with-property 'gnus-next)
-	    (gnus-remove-text-with-property 'gnus-decoration)
-	    (insert
-	     (prog1
-		 (buffer-substring-no-properties (point-min) (point-max))
-	       (erase-buffer)))
-	    ;; Find the original headers.
-	    (set-buffer gnus-original-article-buffer)
-	    (goto-char (point-min))
-	    (while (looking-at message-unix-mail-delimiter)
-	      (forward-line 1))
-	    (let ((mail-header-separator ""))
-	      (setq beg (point)
-		    end (or (message-goto-body)
-			    ;; There may be just a header.
-			    (point-max))))
-	    ;; Delete the headers from the displayed articles.
-	    (set-buffer gnus-article-copy)
-	    (let ((mail-header-separator ""))
-	      (delete-region (goto-char (point-min))
-			     (or (message-goto-body) (point-max))))
-	    ;; Insert the original article headers.
-	    (insert-buffer-substring gnus-original-article-buffer beg end)
-	    ;; Decode charsets.
-	    (let ((gnus-article-decode-hook
-		   (delq 'article-decode-charset
-			 (copy-sequence gnus-article-decode-hook)))
-		  (rfc2047-quote-decoded-words-containing-tspecials t))
-	      (run-hooks 'gnus-article-decode-hook)))))
-      gnus-article-copy)))
+    (unless (gnus-buffer-live-p article-buffer)
+      (error "Can't find any article buffer"))
+    (gnus-msg-inherit-variables (get-buffer article-buffer) gnus-article-copy)
+    (with-current-buffer article-buffer
+      (let ((gnus-newsgroup-charset (or gnus-article-charset
+                                        gnus-newsgroup-charset))
+            (inhibit-read-only t)
+            (gnus-newsgroup-ignored-charsets
+             (or gnus-article-ignored-charsets
+                 gnus-newsgroup-ignored-charsets)))
+        (save-restriction
+          ;; Copy over the (displayed) article buffer, delete
+          ;; hidden text and remove text properties.
+          (widen)
+          (copy-to-buffer gnus-article-copy (point-min) (point-max))
+          (with-current-buffer gnus-article-copy
+            (when yank-string
+              (message-goto-body)
+              (delete-region (point) (point-max))
+              (insert yank-string))
+            (gnus-article-delete-text-of-type 'annotation)
+            (gnus-article-delete-text-of-type 'multipart)
+            (gnus-remove-text-with-property 'gnus-prev)
+            (gnus-remove-text-with-property 'gnus-next)
+            (gnus-remove-text-with-property 'gnus-decoration)
+            (insert
+             (prog1
+                 (buffer-substring-no-properties (point-min) (point-max))
+               (erase-buffer))))
+          ;; Find the original headers.
+          (with-current-buffer gnus-original-article-buffer
+            (goto-char (point-min))
+            (while (looking-at message-unix-mail-delimiter)
+              (forward-line 1))
+            (let ((mail-header-separator ""))
+              (setq beg (point)
+                    end (or (message-goto-body)
+                            ;; There may be just a header.
+                            (point-max)))))
+          ;; Delete the headers from the displayed articles.
+          (with-current-buffer gnus-article-copy
+            (let ((mail-header-separator ""))
+              (delete-region (goto-char (point-min))
+                             (or (message-goto-body) (point-max))))
+            ;; Insert the original article headers.
+            (insert-buffer-substring gnus-original-article-buffer beg end)
+            ;; Decode charsets.
+            (let ((gnus-article-decode-hook
+                   (delq 'article-decode-charset
+                         (copy-sequence gnus-article-decode-hook)))
+                  (rfc2047-quote-decoded-words-containing-tspecials t))
+              (run-hooks 'gnus-article-decode-hook))))))
+    gnus-article-copy))
+
+(defmacro gnus-msg-preserve-variables (parent-buffer &rest body)
+  "If BODY changes the current buffer, ensure important variables preserved."
+  (declare (indent 1))
+  `(progn
+     ,@body
+     (unless (eq ,parent-buffer (current-buffer))
+       (gnus-msg-inherit-variables ,parent-buffer (current-buffer)))))
+
+(defun gnus-msg-inherit-variables (source-buffer dest-buffer)
+  "Transfer formerly global variables from SOURCE-BUFFER to DEST-BUFFER."
+  (with-current-buffer dest-buffer
+    (mapc (lambda (pair)
+            (set (make-local-variable (car pair))
+                 (cdr pair)))
+          (cl-mapcan (lambda (variable)
+                       (when (local-variable-if-set-p variable)
+                         (list `(,variable . ,(buffer-local-value
+                                               variable
+                                               source-buffer)))))
+                     '(gnus-summary-buffer
+                       gnus-article-buffer
+                       gnus-original-article-buffer
+                       gnus-newsgroup-name
+                       gnus-article-current
+                       gnus-current-article)))))
 
 (defun gnus-post-news (post &optional group header article-buffer yank _subject
 			    force-news)
@@ -963,13 +980,15 @@ gnus-post-news
 		     (and (not (gnus-virtual-group-p pgroup)) group)))
 	      (set-buffer gnus-article-copy)
 	      (gnus-msg-treat-broken-reply-to)
-	      (message-followup (if (or newsgroup-p force-news)
-				    (if (save-restriction
-					  (article-narrow-to-head)
-					  (message-fetch-field "newsgroups"))
-					nil
-				      "")
-				  to-group)))
+              (let ((parent-buffer (current-buffer)))
+                (gnus-msg-preserve-variables parent-buffer
+                  (message-followup (if (or newsgroup-p force-news)
+                                        (if (save-restriction
+                                              (article-narrow-to-head)
+                                              (message-fetch-field "newsgroups"))
+                                            nil
+                                          "")
+                                      to-group)))))
 	  ;; The is mail.
 	  (if post
 	      (progn
@@ -983,7 +1002,9 @@ gnus-post-news
 			message-send-actions)))
 	    (set-buffer gnus-article-copy)
 	    (gnus-msg-treat-broken-reply-to)
-	    (message-wide-reply to-address)))
+            (let ((parent-buffer (current-buffer)))
+              (gnus-msg-preserve-variables parent-buffer
+                (message-wide-reply to-address)))))
 	(when yank
 	  (gnus-inews-yank-articles yank))))))
 
@@ -1027,10 +1048,9 @@ gnus-post-method
 		 (if (listp (car gnus-post-method))
 		     gnus-post-method
 		   (list gnus-post-method)))
-	       gnus-secondary-select-methods
+	       gnus-select-methods
 	       (mapcar #'cdr gnus-server-alist)
 	       (mapcar #'car gnus-opened-servers)
-	       (list gnus-select-method)
 	       (list group-method)))
 	     method-alist post-methods method)
 	;; Weed out all mail methods.
@@ -1105,10 +1125,11 @@ gnus-summary-reply
 If prefix argument YANK is non-nil, the original article is yanked
 automatically.
 If WIDE, make a wide reply.
-If VERY-WIDE, make a very wide reply."
-  (interactive (list (and current-prefix-arg
-			  (gnus-summary-work-articles 1)))
-	       gnus-summary-mode)
+VERY-WIDE is a list of other articles to reply to."
+  (interactive
+   (list (and current-prefix-arg
+	      (gnus-summary-work-articles 1)))
+   gnus-summary-mode)
   ;; Allow user to require confirmation before replying by mail to the
   ;; author of a news article (or mail message).
   (when (or (not (or (gnus-news-group-p gnus-newsgroup-name)
@@ -1120,40 +1141,38 @@ gnus-summary-reply
 			(funcall gnus-confirm-mail-reply-to-news
 				 gnus-newsgroup-name))
 		       (t gnus-confirm-mail-reply-to-news)))
-	    (if (or wide very-wide)
-		t ;; Ignore gnus-confirm-mail-reply-to-news for wide and very
-		  ;; wide replies.
-	      (y-or-n-p "Really reply by mail to article author? ")))
-    (let* ((article
-	    (if (listp (car yank))
-		(caar yank)
-	      (car yank)))
+	    (or wide very-wide
+                (y-or-n-p "Really reply by mail to article author? ")))
+    (let* ((article (if (listp (car yank)) (caar yank) (car yank)))
 	   (gnus-article-reply (or article (gnus-summary-article-number)))
-	   (gnus-article-yanked-articles yank)
-	   (headers ""))
+	   (gnus-article-yanked-articles yank))
       ;; Stripping headers should be specified with mail-yank-ignored-headers.
       (when yank
 	(gnus-summary-goto-subject article))
       (gnus-setup-message (if yank 'reply-yank 'reply)
-	(if (not very-wide)
-	    (gnus-summary-select-article)
-	  (dolist (article very-wide)
-	    (gnus-summary-select-article nil nil nil article)
-	    (with-current-buffer (gnus-copy-article-buffer)
-	      (gnus-msg-treat-broken-reply-to)
-	      (save-restriction
-		(message-narrow-to-head)
-		(setq headers (concat headers (buffer-string)))))))
+        (gnus-summary-select-article nil nil nil gnus-article-reply)
 	(set-buffer (gnus-copy-article-buffer))
 	(gnus-msg-treat-broken-reply-to gnus-msg-force-broken-reply-to)
-	(save-restriction
-	  (message-narrow-to-head)
-	  (when very-wide
-	    (erase-buffer)
-	    (insert headers))
-	  (goto-char (point-max)))
-	(mml-quote-region (point) (point-max))
-	(message-reply nil wide)
+        (save-restriction
+          (message-narrow-to-head)
+          (when-let ((very-wide-headers
+                      (save-current-buffer
+                        (let (result)
+                          (dolist (art very-wide result)
+                            (gnus-summary-select-article nil nil nil art)
+                            (with-current-buffer (gnus-copy-article-buffer)
+                              (gnus-msg-treat-broken-reply-to)
+                              (save-restriction
+                                (message-narrow-to-head)
+                                (setq result (concat (or result "")
+                                                     (buffer-string))))))))))
+            (erase-buffer)
+            (insert very-wide-headers))
+          (goto-char (point-max)))
+        (let ((parent-buffer (current-buffer)))
+          (gnus-msg-preserve-variables parent-buffer
+            (mml-quote-region (point) (point-max))
+            (message-reply nil wide)))
 	(when yank
 	  (gnus-inews-yank-articles yank))
 	(gnus-summary-handle-replysign)))))
diff --git a/lisp/gnus/gnus-notifications.el b/lisp/gnus/gnus-notifications.el
index 8646904637..aeb590c28c 100644
--- a/lisp/gnus/gnus-notifications.el
+++ b/lisp/gnus/gnus-notifications.el
@@ -35,7 +35,6 @@
 (require 'gnus-group)
 (require 'gnus-int)
 (require 'gnus-art)
-(require 'gnus-util)
 (ignore-errors
   (require 'google-contacts))        ; Optional
 (require 'gnus-fun)
diff --git a/lisp/gnus/gnus-picon.el b/lisp/gnus/gnus-picon.el
index fd4d3b8a76..a65521b458 100644
--- a/lisp/gnus/gnus-picon.el
+++ b/lisp/gnus/gnus-picon.el
@@ -37,8 +37,6 @@
 ;;
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
-
 (require 'gnus)
 (require 'gnus-art)
 
diff --git a/lisp/gnus/gnus-registry.el b/lisp/gnus/gnus-registry.el
index 0468d72edd..1bca887889 100644
--- a/lisp/gnus/gnus-registry.el
+++ b/lisp/gnus/gnus-registry.el
@@ -79,16 +79,14 @@
 
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
-(eval-when-compile (require 'subr-x))
 
 (require 'gnus)
 (require 'gnus-int)
 (require 'gnus-sum)
 (require 'gnus-art)
-(require 'gnus-util)
 (require 'nnmail)
 (require 'registry)
+(require 'subr-x)
 
 (defvar gnus-adaptive-word-syntax-table)
 
@@ -1187,7 +1185,7 @@ gnus-registry-initialize
   (gnus-registry-install-shortcuts)
   (if (gnus-alive-p)
       (gnus-registry-load)
-    (add-hook 'gnus-read-newsrc-el-hook #'gnus-registry-load)))
+    (add-hook 'gnus-read-newsrc-hook #'gnus-registry-load)))
 
 (defun gnus-registry-install-hooks ()
   "Install the registry hooks."
@@ -1209,7 +1207,7 @@ gnus-registry-unload-hook
   (remove-hook 'nnmail-spool-hook #'gnus-registry-spool-action)
 
   (remove-hook 'gnus-save-newsrc-hook #'gnus-registry-save)
-  (remove-hook 'gnus-read-newsrc-el-hook #'gnus-registry-load)
+  (remove-hook 'gnus-read-newsrc-hook #'gnus-registry-load)
 
   (remove-hook 'gnus-summary-prepare-hook #'gnus-registry-register-message-ids)
   (setq gnus-registry-enabled nil))
diff --git a/lisp/gnus/gnus-salt.el b/lisp/gnus/gnus-salt.el
index 5b746a8efa..6fb1282a1e 100644
--- a/lisp/gnus/gnus-salt.el
+++ b/lisp/gnus/gnus-salt.el
@@ -24,8 +24,6 @@
 
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
-
 (require 'gnus)
 (require 'gnus-sum)
 (require 'gnus-win)
@@ -110,7 +108,7 @@ gnus-pick-mode
     ;; Change line format.
     (setq gnus-summary-line-format gnus-summary-pick-line-format)
     (setq gnus-summary-line-format-spec nil)
-    (gnus-update-format-specifications nil 'summary)
+    (gnus-update-format-specifications 'summary)
     (gnus-update-summary-mark-positions)
     ;; FIXME: a buffer-local minor mode adding globally to a hook??
     (add-hook 'gnus-message-setup-hook #'gnus-pick-setup-message)
@@ -457,8 +455,7 @@ gnus-tree-mode
   (buffer-disable-undo)
   (setq buffer-read-only t)
   (setq truncate-lines t)
-  (save-current-buffer
-    (gnus-set-work-buffer)
+  (gnus-with-temp-buffer
     (gnus-tree-node-insert (make-mail-header "") nil)
     (setq gnus-tree-node-length (1- (point)))))
 
diff --git a/lisp/gnus/gnus-score.el b/lisp/gnus/gnus-score.el
index f40da9e9c4..3e71bb56c4 100644
--- a/lisp/gnus/gnus-score.el
+++ b/lisp/gnus/gnus-score.el
@@ -460,7 +460,7 @@ gnus-adaptive-word-score-alist
 (defvar gnus-score-trace nil)
 (defvar gnus-score-edit-buffer nil)
 
-(defvar gnus-score-alist nil
+(defvar-local gnus-score-alist nil
   "Alist containing score information.
 The keys can be symbols or strings.  The following symbols are defined.
 
@@ -1444,24 +1444,21 @@ gnus-score-save
   ;; Save all score information.
   (let ((cache gnus-score-cache)
 	entry score file)
-    (save-excursion
+    (with-temp-buffer
       (setq gnus-score-alist nil)
-      (nnheader-set-temp-buffer " *Gnus Scores*")
       (while cache
-	(current-buffer)
 	(setq entry (pop cache)
 	      file (nnheader-translate-file-chars (car entry) t)
 	      score (cdr entry))
-	(if (or (not (equal (gnus-score-get 'touched score) '(t)))
-		(gnus-score-get 'read-only score)
-		(and (file-exists-p file)
-		     (not (file-writable-p file))))
-	    ()
+	(when (and (equal (gnus-score-get 'touched score) '(t))
+		   (not (gnus-score-get 'read-only score))
+		   (or (not (file-exists-p file))
+		       (file-writable-p file)))
 	  (setq score (setcdr entry (assq-delete-all 'touched score)))
 	  (erase-buffer)
 	  (let (emacs-lisp-mode-hook)
 	    (if (and (not gnus-adaptive-pretty-print)
-		     (string-match
+		     (string-match-p
 		      (concat (regexp-quote gnus-adaptive-file-suffix) "$")
 		      file))
 		;; This is an adaptive score file, so we do not run it through
@@ -1482,10 +1479,9 @@ gnus-score-save
 		(gnus-write-buffer file))
 	      (when gnus-score-after-write-file-function
 		(funcall gnus-score-after-write-file-function file)))))
-	(and gnus-score-uncacheable-files
-	     (string-match gnus-score-uncacheable-files file)
-	     (gnus-score-remove-from-cache file)))
-      (kill-buffer (current-buffer)))))
+	(when (and gnus-score-uncacheable-files
+	           (string-match-p gnus-score-uncacheable-files file))
+	  (gnus-score-remove-from-cache file))))))
 
 (defun gnus-score-load-files (score-files)
   "Load all score files in SCORE-FILES."
@@ -1524,8 +1520,7 @@ gnus-score-headers
     (while news
       (setq scores news
 	    news nil)
-      (when (and gnus-summary-default-score
-		 scores)
+      (when (and gnus-summary-default-score scores)
 	(let* ((entries gnus-header-index)
 	       (now (time-to-days nil))
 	       (expire (and gnus-score-expiry-days
@@ -1544,8 +1539,7 @@ gnus-score-headers
 		    (cons (cons header (or gnus-summary-default-score 0))
 			  gnus-scores-articles))))
 
-	  (with-current-buffer (gnus-get-buffer-create "*Headers*")
-	    (buffer-disable-undo)
+	  (with-temp-buffer
 	    (when (gnus-buffer-live-p gnus-summary-buffer)
 	      (message-clone-locals gnus-summary-buffer))
 
@@ -1589,9 +1583,7 @@ gnus-score-headers
 	    (when (gnus-buffer-live-p gnus-summary-buffer)
 	      (let ((scored gnus-newsgroup-scored))
 		(with-current-buffer gnus-summary-buffer
-		  (setq gnus-newsgroup-scored scored))))
-	    ;; Remove the buffer.
-	    (gnus-kill-buffer (current-buffer)))
+		  (setq gnus-newsgroup-scored scored)))))
 
 	  ;; Add articles to `gnus-newsgroup-scored'.
 	  (while gnus-scores-articles
@@ -2916,7 +2908,7 @@ gnus-sort-score-files
     (let ((alist
 	   (mapcar
 	    (lambda (file)
-	      (cons (inline (gnus-score-file-rank file)) file))
+	      (cons (gnus-score-file-rank file) file))
 	    files)))
       (mapcar #'cdr (sort alist #'car-less-than-car)))))
 
diff --git a/lisp/gnus/gnus-search.el b/lisp/gnus/gnus-search.el
index fc9f8684f6..91f2decaf8 100644
--- a/lisp/gnus/gnus-search.el
+++ b/lisp/gnus/gnus-search.el
@@ -81,9 +81,8 @@
 (require 'gnus-group)
 (require 'gnus-sum)
 (require 'message)
-(require 'gnus-util)
 (require 'eieio)
-(eval-when-compile (require 'cl-lib))
+
 (autoload 'eieio-build-class-alist "eieio-opt")
 (autoload 'nnmaildir-base-name-to-article-number "nnmaildir")
 
@@ -1024,7 +1023,7 @@ gnus-search-run-search
       ;; We should only be doing this once, in
       ;; `nnimap-open-connection', but it's too frustrating to try to
       ;; get to the server from the process buffer.
-      (with-current-buffer (nnimap-buffer)
+      (with-current-buffer (nnimap-process-buffer)
 	(setf (slot-value engine 'literal-plus)
 	      (when (nnimap-capability "LITERAL+") t))
 	;; MULTISEARCH not yet implemented.
@@ -1062,7 +1061,7 @@ gnus-search-run-search
 		  (or (null single-search) (null artlist)))
 	(when (nnimap-change-group
 	       (gnus-group-short-name group) server)
-	  (with-current-buffer (nnimap-buffer)
+	  (with-current-buffer (nnimap-process-buffer)
 	    (message "Searching %s..." group)
 	    (let ((result
 		   (gnus-search-imap-search-command engine q-string)))
diff --git a/lisp/gnus/gnus-spec.el b/lisp/gnus/gnus-spec.el
index cb60108ea9..ec7c7e7406 100644
--- a/lisp/gnus/gnus-spec.el
+++ b/lisp/gnus/gnus-spec.el
@@ -24,14 +24,12 @@
 
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
-(defvar gnus-newsrc-file-version)
-
 (require 'gnus)
 
 ;;; Internal variables.
 
-(defvar gnus-summary-mark-positions nil)
+(defvar gnus-newsrc-file-version)
+(defvar-local gnus-summary-mark-positions nil)
 (defvar gnus-group-mark-positions nil)
 (defvar gnus-group-indentation "")
 
@@ -129,13 +127,12 @@ gnus-update-format
     (lisp-interaction-mode)
     (insert (gnus-pp-to-string spec))))
 
-(defun gnus-update-format-specifications (&optional force &rest types)
+(defun gnus-update-format-specifications (&rest types)
   "Update all (necessary) format specifications.
 Return a list of updated types."
   ;; Make the indentation array.
   ;; See whether all the stored info needs to be flushed.
-  (when (or force
-	    (not gnus-newsrc-file-version)
+  (when (or (not gnus-newsrc-file-version)
 	    (not (equal (gnus-continuum-version)
 			(gnus-continuum-version gnus-newsrc-file-version)))
 	    (not (equal emacs-version
@@ -374,56 +371,55 @@ gnus-parse-format
     (if (string-match
 	 "\\`\\(.*\\)%[0-9]?[{(«]\\(.*\\)%[0-9]?[»})]\\(.*\n?\\)\\'\\|%[-0-9]*=\\|%[-0-9]*\\*"
 	 format)
-	(gnus-parse-complex-format format spec-alist)
+        (gnus-parse-complex-format format spec-alist)
       ;; This is a simple format.
       (gnus-parse-simple-format format spec-alist insert))))
 
 (defun gnus-parse-complex-format (format spec-alist)
-  (let ((cursor-spec nil))
-    (save-excursion
-      (gnus-set-work-buffer)
-      (insert format)
-      (goto-char (point-min))
-      (while (re-search-forward "\"" nil t)
-	(replace-match "\\\"" nil t))
-      (goto-char (point-min))
-      (insert "(\"")
-      ;; Convert all font specs into font spec lists.
-      (while (re-search-forward "%\\([0-9]+\\)?\\([«»{}()]\\)" nil t)
-	(let ((number (if (match-beginning 1)
-			  (match-string 1) "0"))
-	      (delim (aref (match-string 2) 0)))
-	  (if (or (= delim ?\()
-		  (= delim ?\{)
-		  (= delim 171)) ; «
-	      (replace-match (concat "\"("
-				     (cond ((= delim ?\() "mouse")
-					   ((= delim ?\{) "face")
-					   (t "balloon"))
-				     " " number " \"")
-			     t t)
-	    (replace-match "\")\""))))
-      (goto-char (point-max))
-      (insert "\")")
-      ;; Convert point position commands.
-      (goto-char (point-min))
+  (gnus-with-temp-buffer
+    (insert format)
+    (goto-char (point-min))
+    (while (re-search-forward "\"" nil t)
+      (replace-match "\\\"" nil t))
+    (goto-char (point-min))
+    (insert "(\"")
+    ;; Convert all font specs into font spec lists.
+    (while (re-search-forward "%\\([0-9]+\\)?\\([«»{}()]\\)" nil t)
+      (let ((number (if (match-beginning 1)
+			(match-string 1) "0"))
+	    (delim (aref (match-string 2) 0)))
+	(if (or (= delim ?\()
+		(= delim ?\{)
+		(= delim 171)) ; «
+	    (replace-match (concat "\"("
+				   (cond ((= delim ?\() "mouse")
+					 ((= delim ?\{) "face")
+					 (t "balloon"))
+				   " " number " \"")
+			   t t)
+	  (replace-match "\")\""))))
+    (goto-char (point-max))
+    (insert "\")")
+    ;; Convert point position commands.
+    (goto-char (point-min))
+    (let (cursor-spec)
       (let ((case-fold-search nil))
-	(while (re-search-forward "%\\([-0-9]+\\)?\\*" nil t)
+        (while (re-search-forward "%\\([-0-9]+\\)?\\*" nil t)
 	  (replace-match "\"(point)\"" t t)
 	  (setq cursor-spec t)))
       ;; Convert TAB commands.
       (goto-char (point-min))
       (while (re-search-forward "%\\([-0-9]+\\)=" nil t)
-	(replace-match (format "\"(tab %s)\"" (match-string 1)) t t))
+        (replace-match (format "\"(tab %s)\"" (match-string 1)) t t))
       ;; Convert the buffer into the spec.
       (goto-char (point-min))
       (let ((form (read (current-buffer))))
-	(if cursor-spec
+        (if cursor-spec
 	    `(let (gnus-position)
 	       ,@(gnus-complex-form-to-spec form spec-alist)
 	       (if gnus-position
 		   (put-text-property gnus-position (1+ gnus-position)
-					   'gnus-position t)))
+				      'gnus-position t)))
 	  `(progn
 	     ,@(gnus-complex-form-to-spec form spec-alist)))))))
 
@@ -452,8 +448,7 @@ gnus-parse-simple-format
 	spec flist fstring elem result dontinsert user-defined
 	type value pad-width spec-beg cut-width ignore-value
 	tilde-form tilde elem-type extended-spec)
-    (save-excursion
-      (gnus-set-work-buffer)
+    (gnus-with-temp-buffer
       (insert format)
       (goto-char (point-min))
       (while (re-search-forward "%" nil t)
diff --git a/lisp/gnus/gnus-srvr.el b/lisp/gnus/gnus-srvr.el
index f66f8427ea..6dfd8d9050 100644
--- a/lisp/gnus/gnus-srvr.el
+++ b/lisp/gnus/gnus-srvr.el
@@ -24,8 +24,6 @@
 
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
-
 (require 'gnus)
 (require 'gnus-start)
 (require 'gnus-spec)
@@ -754,8 +752,8 @@ gnus-browse-foreign-server
   (setq gnus-browse-current-method (gnus-server-to-method server))
   (setq gnus-browse-return-buffer return-buffer)
   (let* ((method gnus-browse-current-method)
-	 (orig-select-method gnus-select-method)
-	 (gnus-select-method method)
+	 (orig-select-methods gnus-select-methods)
+	 (gnus-select-methods (list method))
 	 groups group)
     (gnus-message 5 "Connecting to %s..." (nth 1 method))
     (cond
@@ -822,7 +820,7 @@ gnus-browse-foreign-server
 			 (lambda (l1 l2)
 			   (string< (car l1) (car l2)))))
       (if gnus-server-browse-in-group-buffer
-	  (let* ((gnus-select-method orig-select-method)
+	  (let* ((gnus-select-methods orig-select-methods)
 		 (gnus-group-listed-groups
 		  (mapcar (lambda (group)
 			    (let ((name
@@ -846,7 +844,7 @@ gnus-browse-foreign-server
 		"Gnus: %%b {%s:%s}" (car method) (cadr method))))
 	(let ((buffer-read-only nil)
 	      name
-	      (prefix (let ((gnus-select-method orig-select-method))
+	      (prefix (let ((gnus-select-methods orig-select-methods))
 			(gnus-group-prefixed-name "" method))))
 	  (while (setq group (pop groups))
 	    (add-text-properties
diff --git a/lisp/gnus/gnus-start.el b/lisp/gnus/gnus-start.el
index 44e97d5484..a3360769fb 100644
--- a/lisp/gnus/gnus-start.el
+++ b/lisp/gnus/gnus-start.el
@@ -29,47 +29,49 @@
 (require 'gnus-int)
 (require 'gnus-spec)
 (require 'gnus-range)
-(require 'gnus-util)
 (require 'gnus-cloud)
 (require 'gnus-dbus)
+(require 'nnmail)
+
 (autoload 'message-make-date "message")
 (autoload 'gnus-agent-read-servers-validate "gnus-agent")
 (autoload 'gnus-agent-save-local "gnus-agent")
 (autoload 'gnus-agent-possibly-alter-active "gnus-agent")
-(declare-function gnus-group-decoded-name "gnus-group" (string))
+(autoload 'gnus-agent-save-active "gnus-agent")
+(autoload 'gnus-agentize "gnus-agent" nil t)
 
-(eval-when-compile (require 'cl-lib))
+(declare-function gnus-group-decoded-name "gnus-group" (string))
+(declare-function gnus-group-default-level "gnus-group")
 
 (defvar gnus-agent-covered-methods)
 (defvar gnus-agent-file-loading-local)
 (defvar gnus-agent-file-loading-cache)
 (defvar gnus-topic-alist)
+(defvar gnus-inhibit-demon)
 
-(defcustom gnus-startup-file (nnheader-concat gnus-home-directory ".newsrc")
-  "Your `.newsrc' file.
-`.newsrc-SERVER' will be used instead if that exists."
-  :group 'gnus-start
-  :type 'file)
+(defconst gnus-thread-group "gnus-get-unread-articles"
+  "Identifying prefix for fetching threads.")
 
-(defcustom gnus-backup-startup-file 'never
-  "Control use of version numbers for backups of `gnus-startup-file'.
-This variable takes the same values as the `version-control'
-variable."
-  :version "22.1"
+(defcustom gnus-max-seconds-hold-mutex 75
+  "Timeout in seconds before relinquishing `gnus-mutex-get-unread-articles'."
   :group 'gnus-start
-  :type '(choice (const :tag "Never" never)
-		 (const :tag "If existing" nil)
-		 (other :tag "Always" t)))
-
-(defcustom gnus-save-startup-file-via-temp-buffer t
-  "Whether to write the startup file contents to a buffer then save
-the buffer or write directly to the file.  The buffer is faster
-because all of the contents are written at once.  The direct write
-uses considerably less memory."
-  :version "22.1"
+  :type 'integer)
+
+(defvar gnus-mutex-get-unread-articles (make-mutex gnus-thread-group)
+  "Updating or displaying state of unread articles are critical sections.")
+
+(defconst gnus-dot-newsrc (nnheader-concat gnus-home-directory ".newsrc")
+  "Traditional Usenet .newsrc file.  Its time is long past.")
+
+(defcustom gnus-newsrc-file (nnheader-concat gnus-home-directory ".newsrc.eld")
+  "So-called El Dingo state file.  Do not change this."
   :group 'gnus-start
-  :type '(choice (const :tag "Write via buffer" t)
-                 (const :tag "Write directly to file" nil)))
+  :type 'file)
+
+(make-obsolete-variable 'gnus-startup-file 'gnus-newsrc-file "28.1")
+
+(make-obsolete-variable 'gnus-backup-startup-file nil "28.1")
+(make-obsolete-variable 'gnus-save-startup-file-via-temp-buffer nil "28.1")
 
 (defcustom gnus-init-file (nnheader-concat gnus-home-directory ".gnus")
   "Your Gnus Emacs Lisp startup file name.
@@ -109,7 +111,7 @@ gnus-check-new-newsgroups
 or killed.
 
 When any of the following are true, `gnus-find-new-newsgroups' will instead
-ask the servers (primary, secondary, and archive servers) to list new
+ask the servers (including the archive server) to list new
 groups since the last time it checked:
   1. This variable is `ask-server'.
   2. This variable is a list of select methods (see below).
@@ -121,8 +123,7 @@ gnus-check-new-newsgroups
 longer necessary, so you could safely set `gnus-save-killed-list' to nil.
 
 This variable can be a list of select methods which Gnus will query with
-the `ask-server' method in addition to the primary, secondary, and archive
-servers.
+the `ask-server' method in addition to the archive server.
 
 E.g.:
   (setq gnus-check-new-newsgroups
@@ -217,24 +218,15 @@ gnus-activate-foreign-newsgroups
   :type '(choice integer
 		 (const :tag "none" nil)))
 
-(defcustom gnus-read-newsrc-file t
-  "Non-nil means that Gnus will read the `.newsrc' file.
-Gnus always reads its own startup file, which is called
-\".newsrc.eld\".  The file called \".newsrc\" is in a format that can
-be readily understood by other newsreaders.  If you don't plan on
-using other newsreaders, set this variable to nil to save some time on
-entry."
-  :version "21.1"
-  :group 'gnus-newsrc
-  :type 'boolean)
+(make-obsolete-variable 'gnus-read-newsrc-file nil "28.1")
+
+(make-obsolete-variable 'gnus-save-newsrc-file 'gnus-save-dot-newsrc "28.1")
 
+(defvaralias 'gnus-save-dot-newsrc 'gnus-save-newsrc-file)
 (defcustom gnus-save-newsrc-file t
-  "Non-nil means that Gnus will save the `.newsrc' file.
-Gnus always saves its own startup file, which is called
-\".newsrc.eld\".  The file called \".newsrc\" is in a format that can
-be readily understood by other newsreaders.  If you don't plan on
-using other newsreaders, set this variable to nil to save some time on
-exit."
+  "Save a Usenet .newsrc for nntp groups.
+Note the .newsrc is primarily for the benefit of other newsreaders.
+Gnus uses .newsrc.eld, not .newsrc."
   :group 'gnus-newsrc
   :type 'boolean)
 
@@ -378,6 +370,17 @@ gnus-options-not-subscribe
   :type '(choice regexp
 		 (const :tag "none" nil)))
 
+(defcustom gnus-background-get-unread-articles nil
+  "Instantiate background thread for `gnus-get-unread-articles' which
+covers most of the network retrieval when `gnus-group-get-new-news' is run."
+  :group 'gnus-start
+  :type 'boolean
+  :set (lambda (symbol value)
+         (set-default symbol value)
+         (when value (unless (featurep 'threads)
+                       (set-default symbol nil)
+                       (gnus-message 5 "Threads unsupported")))))
+
 (defcustom gnus-modtime-botch nil
   "Non-nil means .newsrc should be deleted prior to save.
 Its use is due to the bogus appearance that .newsrc was modified on
@@ -439,27 +442,20 @@ gnus-after-getting-new-news-hook
   :group 'gnus-group-new
   :type 'hook)
 
-(defcustom gnus-read-newsrc-el-hook nil
-  "A hook called after reading the newsrc.eld? file."
+(defcustom gnus-read-newsrc-hook nil
+  "A hook called after reading the newsrc.eld file."
   :group 'gnus-newsrc
   :type 'hook)
 
-(defcustom gnus-save-newsrc-hook nil
-  "A hook called before saving any of the newsrc files."
-  :group 'gnus-newsrc
-  :type 'hook)
+(make-obsolete-variable 'gnus-read-newsrc-el-hook 'gnus-read-newsrc-hook "28.1")
 
-(defcustom gnus-save-quick-newsrc-hook nil
-  "A hook called just before saving the quick newsrc file.
-Can be used to turn version control on or off."
+(defcustom gnus-save-newsrc-hook nil
+  "A hook called before saving the newsrc.eld file."
   :group 'gnus-newsrc
   :type 'hook)
 
-(defcustom gnus-save-standard-newsrc-hook nil
-  "A hook called just before saving the standard newsrc file.
-Can be used to turn version control on or off."
-  :group 'gnus-newsrc
-  :type 'hook)
+(make-obsolete-variable 'gnus-save-quick-newsrc-hook nil "28.1")
+(make-obsolete-variable 'gnus-save-standard-newsrc-hook nil "28.1")
 
 (defcustom gnus-group-mode-hook nil
   "Hook for Gnus group mode."
@@ -491,14 +487,17 @@ gnus-newsrc-options-n
 (defvar gnus-newsrc-last-checked-date nil
   "Date Gnus last asked server for new newsgroups.")
 
-(defvar gnus-current-startup-file nil
-  "Startup file for the current host.")
-
 ;; Byte-compiler warning.
 (defvar gnus-group-line-format)
 
 ;; Suggested by Brian Edmonds <edmonds@cs.ubc.ca>.
 (defvar gnus-init-inhibit nil)
+
+(defvar gnus-thread-start nil
+  "(lisp-time . thread) when background thread got mutex.
+The macro `with-timeout' within thread body is verboten since handlerlist is not
+thread-safe in eval.c.")
+
 (defun gnus-read-init-file (&optional inhibit-next)
   ;; Don't load .gnus if the -q option was used.
   (when init-file-user
@@ -594,7 +593,7 @@ gnus-subscribe-alphabetically
 (defun gnus-subscribe-hierarchically (newgroup)
   "Subscribe new NEWGROUP and insert it in hierarchical newsgroup order."
   ;; Basic ideas by mike-w@cs.aukuni.ac.nz (Mike Williams)
-  (with-current-buffer (nnheader-find-file-noselect gnus-current-startup-file)
+  (with-current-buffer (nnheader-find-file-noselect gnus-dot-newsrc)
     (prog1
 	(let ((groupkey newgroup) before)
 	  (while (and (not before) groupkey)
@@ -710,9 +709,8 @@ gnus-clear-system
 	gnus-ephemeral-servers nil)
   (gnus-shutdown 'gnus)
   ;; Kill the startup file.
-  (and gnus-current-startup-file
-       (get-file-buffer gnus-current-startup-file)
-       (kill-buffer (get-file-buffer gnus-current-startup-file)))
+  (when-let ((buffer (get-file-buffer gnus-newsrc-file)))
+    (kill-buffer buffer))
   ;; Clear the dribble buffer.
   (gnus-dribble-clear)
   ;; Kill global KILL file buffer.
@@ -755,7 +753,6 @@ gnus-1
 	 (and (numberp arg)
 	      (> arg 0)
 	      (max (car gnus-group-list-mode) arg))))
-
     (gnus-clear-system)
     (gnus-splash)
     (gnus-run-hooks 'gnus-before-startup-hook)
@@ -769,8 +766,8 @@ gnus-1
       (add-to-list 'gnus-predefined-server-alist
 		   (cons "native" gnus-select-method)))
 
-    (if gnus-agent
-	(gnus-agentize))
+    (when gnus-agent
+      (gnus-agentize))
 
     (let ((level (and (numberp arg) (> arg 0) arg))
 	  did-connect)
@@ -784,9 +781,6 @@ gnus-1
 	    ;; Couldn't connect to the server, so bail out.
 	    (gnus-group-quit)
 	  (gnus-run-hooks 'gnus-startup-hook)
-	  ;; Find the current startup file name.
-	  (setq gnus-current-startup-file
-		(gnus-make-newsrc-file gnus-startup-file))
 
 	  ;; Read the dribble file.
 	  (when (or gnus-child gnus-use-dribble-file)
@@ -801,7 +795,7 @@ gnus-1
 	    (gnus-dbus-register-sleep-signal))
 	  (gnus-start-draft-setup)
 	  ;; Generate the group buffer.
-	  (gnus-group-list-groups level)
+          (gnus-group-list-groups level)
 	  (gnus-group-first-unread-group)
 	  (gnus-configure-windows 'group)
 	  (gnus-group-set-mode-line)
@@ -820,7 +814,6 @@ gnus-start-draft-setup
     (gnus-group-set-parameter
      "nndraft:drafts" 'gnus-dummy '((gnus-draft-mode)))))
 
-
 ;;;
 ;;; Dribble file
 ;;;
@@ -833,8 +826,8 @@ gnus-dribble-file-name
   (concat
    (if gnus-dribble-directory
        (concat (file-name-as-directory gnus-dribble-directory)
-	       (file-name-nondirectory gnus-current-startup-file))
-     gnus-current-startup-file)
+	       (file-name-nondirectory gnus-newsrc-file))
+     gnus-newsrc-file)
    "-dribble"))
 
 (defun gnus-dribble-enter (string &optional regexp)
@@ -882,32 +875,25 @@ gnus-dribble-read-file
       (buffer-disable-undo)
       (bury-buffer (current-buffer))
       (set-buffer-modified-p nil)
-      (let ((auto (make-auto-save-file-name))
-	    (gnus-dribble-ignore t)
-	    (purpose nil)
-	    modes)
-	(when (or (file-exists-p auto) (file-exists-p dribble-file))
-	  ;; Load whichever file is newest -- the auto save file
-	  ;; or the "real" file.
-	  (if (file-newer-than-file-p auto dribble-file)
-	      (nnheader-insert-file-contents auto)
-	    (nnheader-insert-file-contents dribble-file))
+      (let* ((gnus-dribble-ignore t)
+             (auto (make-auto-save-file-name))
+	     (state (if (file-newer-than-file-p auto dribble-file)
+                        auto
+                      dribble-file))
+	     modes)
+	(when (file-exists-p state)
+          (nnheader-insert-file-contents state)
 	  (unless (zerop (buffer-size))
 	    (set-buffer-modified-p t))
 	  ;; Set the file modes to reflect the .newsrc file modes.
 	  (save-buffer)
-	  (when (and (setq modes (file-modes gnus-current-startup-file))
+	  (when (and (setq modes (file-modes gnus-newsrc-file))
 		     (file-exists-p dribble-file))
 	    (gnus-set-file-modes dribble-file modes))
 	  (goto-char (point-min))
-	  (when (search-forward "Gnus was exited on purpose" nil t)
-	    (setq purpose t))
 	  ;; Possibly eval the file later.
 	  (when (or gnus-always-read-dribble-file
-		    (gnus-y-or-n-p
-		     (if purpose
-			 "Gnus exited on purpose without saving; read auto-save file anyway? "
-		     "Gnus auto-save file exists.  Do you want to read it? ")))
+		    (gnus-y-or-n-p (format "Read unsaved state %s? " state)))
 	    (setq gnus-dribble-eval-file t)))))))
 
 (defun gnus-dribble-eval-file ()
@@ -941,27 +927,23 @@ gnus-dribble-clear
       (set-buffer-modified-p nil)
       (setq buffer-saved-size (buffer-size)))))
 
-
 ;;;
 ;;; Active & Newsrc File Handling
 ;;;
 
-(defun gnus-setup-news (&optional rawfile level dont-connect)
+(defun gnus-setup-news (&optional _force level dont-connect)
   "Setup news information.
-If RAWFILE is non-nil, the .newsrc file will also be read.
 If LEVEL is non-nil, the news will be set up at level LEVEL."
-  (require 'nnmail)
-  (let ((init (not (and gnus-newsrc-alist gnus-active-hashtb (not rawfile))))
+  (let ((init (or (not gnus-newsrc-alist) (not gnus-active-hashtb)))
 	;; Binding this variable will inhibit multiple fetchings
 	;; of the same mail source.
 	(nnmail-fetched-sources (list t)))
-
     (when init
       ;; Clear some variables to re-initialize news information.
       (setq gnus-newsrc-alist nil
 	    gnus-active-hashtb nil)
       ;; Read the newsrc file and create `gnus-newsrc-hashtb'.
-      (gnus-read-newsrc-file rawfile))
+      (gnus-read-newsrc-file))
 
     ;; Make sure the archive server is available to all and sundry.
     (let ((method (or (and (stringp gnus-message-archive-method)
@@ -1163,21 +1145,18 @@ gnus-matches-options-n
 (defun gnus-ask-server-for-new-groups ()
   (let* ((new-date (message-make-date))
 	 (date (or gnus-newsrc-last-checked-date new-date))
-	 (methods (cons gnus-select-method
-			(nconc
-			 (when (gnus-archive-server-wanted-p)
-			   (list "archive"))
-			 (append
-			  (and (consp gnus-check-new-newsgroups)
-			       gnus-check-new-newsgroups)
-			  gnus-secondary-select-methods))))
+	 (methods (nconc
+                   (when (gnus-archive-server-wanted-p)
+                     (list "archive"))
+                   (append
+                    (and (consp gnus-check-new-newsgroups)
+                         gnus-check-new-newsgroups)
+                    gnus-select-methods)))
 	 (groups 0)
 	 new-newsgroups got-new method hashtb ;; group
 	 gnus-override-subscribe-method)
     (unless gnus-killed-hashtb
       (gnus-make-hashtable-from-killed))
-    ;; Go through both primary and secondary select methods and
-    ;; request new newsgroups.
     (while (setq method (gnus-server-get-method nil (pop methods)))
       (setq new-newsgroups nil
 	    gnus-override-subscribe-method method)
@@ -1424,81 +1403,56 @@ gnus-cache-active-hashtb
 	  (when (> (cdr cache-active) (cdr active))
 	    (setcdr active (cdr cache-active))))))))
 
-(defun gnus-activate-group (group &optional scan dont-check method
-				  dont-sub-check)
+(defun gnus-activate-group (group
+                            &optional scan dont-check method dont-sub-check)
   "Check whether a group has been activated or not.
 If SCAN, request a scan of that group as well.  If METHOD, use
 that select method instead of determining the method based on the
 group name.  If DONT-CHECK, don't check whether the group
 actually exists.  If DONT-SUB-CHECK or DONT-CHECK, don't let the
 backend check whether the group actually exists."
-  (let ((method (or method (inline (gnus-find-method-for-group group))))
-	active)
-    (and (inline (gnus-check-server method))
-	 ;; We escape all bugs and quit here to make it possible to
-	 ;; continue if a group is so out-there that it reports bugs
-	 ;; and stuff.
-	 (progn
-	   (and scan
-		(gnus-check-backend-function 'request-scan (car method))
-		(gnus-request-scan group method))
-	   t)
-	 (if (or debug-on-error debug-on-quit)
-	     (inline (gnus-request-group group (or dont-sub-check dont-check)
-					 method
-					 (gnus-get-info group)))
-	   (condition-case nil
-	       (inline (gnus-request-group group (or dont-sub-check dont-check)
-					   method
-					   (gnus-get-info group)))
-	     (quit
-	      (if debug-on-quit
-		  (debug "Quit")
-		(message "Quit activating %s" group))
-	      nil)))
-	 (unless dont-check
-	   (setq active (gnus-parse-active))
-	   ;; If there are no articles in the group, the GROUP
-	   ;; command may have responded with the `(0 . 0)'.  We
-	   ;; ignore this if we already have an active entry
-	   ;; for the group.
-	   (if (and (zerop (or (car active) 0))
-		    (zerop (or (cdr active) 0))
-		    (gnus-active group))
-	       (gnus-active group)
-
-             ;; If a cache is present, we may have to alter the active info.
-             (when gnus-use-cache
-               (inline (gnus-cache-possibly-alter-active
-                        group active)))
-
-             ;; If the agent is enabled, we may have to alter the active info.
-             (when gnus-agent
-               (gnus-agent-possibly-alter-active group active))
-
-	     (gnus-set-active group active)
-	     ;; Return the new active info.
-	     active)))))
+  (setq method (or method (gnus-find-method-for-group group)))
+  (when (gnus-check-server method)
+    (when scan
+      (gnus-check-backend-function 'request-scan (car method))
+      (gnus-request-scan group method))
+    (when (and (gnus-request-group group
+                                   (or dont-sub-check dont-check)
+			           method
+			           (gnus-get-info group))
+               (not dont-check))
+      (let ((new-active (gnus-parse-active))
+            (old-active (gnus-active group)))
+        ;; If new active is `(0 . 0)`, then return existing active.
+        (if (and old-active
+                 (cl-every (lambda (e) (or (not (integerp e))
+                                           (zerop e)))
+                           `(,(car new-active) ,(cdr new-active))))
+	    old-active
+          (when gnus-use-cache
+            (gnus-cache-possibly-alter-active group new-active))
+          (when gnus-agent
+            (gnus-agent-possibly-alter-active group new-active))
+	  (gnus-set-active group new-active)
+          new-active)))))
 
 (defun gnus-get-unread-articles-in-group (info active &optional update)
   (when (and info active)
     ;; Allow the backend to update the info in the group.
     (when (and update
 	       (gnus-request-update-info
-		info (inline (gnus-find-method-for-group
-			      (gnus-info-group info)))))
+		info (gnus-find-method-for-group (gnus-info-group info))))
       (gnus-activate-group (gnus-info-group info) nil t))
 
-    (let* ((range (gnus-info-read info))
-	   (num 0))
+    (let ((range (gnus-info-read info))
+	  (num 0))
 
       ;; These checks are present in gnus-activate-group but skipped
       ;; due to setting dont-check in the preceding call.
 
       ;; If a cache is present, we may have to alter the active info.
       (when (and gnus-use-cache info)
-	(inline (gnus-cache-possibly-alter-active
-		 (gnus-info-group info) active)))
+	(gnus-cache-possibly-alter-active (gnus-info-group info) active))
 
       ;; If the agent is enabled, we may have to alter the active info.
       (when (and gnus-agent info)
@@ -1575,197 +1529,300 @@ gnus-get-unread-articles-in-group
 	(setcar (gnus-group-entry (gnus-info-group info)) num))
       num)))
 
-;; Go though `gnus-newsrc-alist' and compare with `gnus-active-hashtb'
-;; and compute how many unread articles there are in each group.
-(defun gnus-get-unread-articles (&optional level dont-connect one-level)
+(defmacro gnus-scope-globals (&rest forms)
+  "Sandbox globals for thread safety."
+  (declare (indent 0))
+  (let ((variables (quote (gnus-newsgroup-name
+                           gnus-newsgroup-marked
+                           gnus-newsgroup-spam-marked
+                           gnus-newsgroup-unreads
+                           gnus-current-headers
+                           gnus-newsgroup-data
+                           gnus-summary-buffer
+                           gnus-article-buffer
+                           gnus-original-article-buffer
+                           gnus-article-current
+                           gnus-current-article
+                           gnus-reffed-article-number
+                           gnus-current-score-file
+                           gnus-newsgroup-charset))))
+    `(progn
+       ,(cons 'inline (mapcar (lambda (v) (list 'defvar v)) variables))
+       (let ,(mapcar (apply-partially #'make-list 2) variables)
+         ,@forms))))
+
+(defun gnus-thread-body (thread-name mtx fns)
+  "Errors need to be trapped for a clean exit.
+Else we get unblocked but permanently yielded threads."
+  (let ((working (get-buffer-create (format " *%s*" thread-name)))
+        (inhibit-debugger t)
+        debug-on-quit
+        debug-on-error)
+    ;; once context switch occurs handlerlist in eval.c(throw) is lost
+    (unwind-protect
+        (condition-case err
+            (with-mutex mtx
+              (setq gnus-thread-start (cons (current-time) (current-thread)))
+              (with-current-buffer working
+                (gnus-message-with-timestamp "gnus-thread-body: start %s <%s>"
+                                             thread-name (buffer-name))
+                ;; buffer-locals not thread-safe (avoid them)
+                (let (gnus-run-thread--subresult
+                      current-fn
+                      (gnus-inhibit-demon t)
+                      (nntp-server-buffer (current-buffer)))
+                  (condition-case err
+                      (dolist (fn fns)
+                        (setq current-fn fn)
+                        (setq gnus-run-thread--subresult
+                              (funcall fn gnus-run-thread--subresult))
+                        (thread-yield))
+                    (error
+                     (ignore-errors (mutex-unlock mtx))
+                     ;; feed current-fn to outer condition-case
+                     (error "dolist: '%s' in %s"
+                            (error-message-string err) current-fn))))))
+          (error (gnus-message-with-timestamp
+                  "gnus-thread-body: error %s '%s'"
+                  thread-name (error-message-string err))))
+      (let (kill-buffer-query-functions)
+        (kill-buffer working))
+      (setq gnus-thread-start nil)
+      (ignore-errors (mutex-unlock mtx))
+      (gnus-message-with-timestamp "gnus-thread-body: finish %s" thread-name))))
+
+(defun gnus-thread-group-running-p (thread-group)
+  (when-let ((thr (cl-some (lambda (thr)
+                             (when (cl-search thread-group (thread-name thr))
+                               thr))
+                           (all-threads))))
+    (if (thread-live-p thr)
+        thr
+      (prog1 nil
+        (thread-signal thr 'error nil)))))
+
+(defun gnus-run-thread (label mtx thread-group &rest fns)
+  "MTX, if non-nil, is the mutex for the new thread.
+THREAD-GROUP is string useful for naming working buffer and threads.
+All FNS must finish before MTX is released."
+  (when fns
+    (let ((thread-name (concat thread-group "-" label)))
+      (make-thread
+       (apply-partially #'gnus-thread-body thread-name mtx fns)
+       thread-name))))
+
+(defun gnus-chain-arg (tack-p f &rest args)
+  (lambda (prev)
+    (apply f (append args (when tack-p (list prev))))))
+
+(defun gnus-time-out-thread ()
+  (interactive)
+  (when gnus-thread-start
+    (cl-destructuring-bind (started . thread)
+        gnus-thread-start
+      (when (time-less-p
+             (time-add started gnus-max-seconds-hold-mutex)
+             nil)
+        (setq gnus-thread-start nil)
+        (if (thread-live-p thread)
+            (progn
+              (gnus-message-with-timestamp
+               "gnus-time-out-thread: signal quit %s" (thread-name thread))
+              (thread-signal thread 'quit nil))
+          (gnus-message-with-timestamp
+           "gnus-time-out-thread: race on dead %s" (thread-name thread)))))))
+
+(cl-defun gnus-get-unread-articles (&optional
+                                    requested-level
+                                    dont-connect
+                                    one-level
+                                    &aux
+                                    (level (gnus-group-default-level requested-level t)))
+  "Workhorse of `gnus-group-get-new-news'."
   (setq gnus-server-method-cache nil)
-  (require 'gnus-agent)
   (defvar gnus-agent-article-local-times)
-  (let* ((newsrc (cdr gnus-newsrc-alist))
-	 (alevel (or level gnus-activate-level (1+ gnus-level-subscribed)))
-	 (foreign-level
-	  (or
-	   level
-	   (min
-	    (cond ((and gnus-activate-foreign-newsgroups
-			(not (numberp gnus-activate-foreign-newsgroups)))
-		   (1+ gnus-level-subscribed))
-		  ((numberp gnus-activate-foreign-newsgroups)
-		   gnus-activate-foreign-newsgroups)
-		  (t 0))
-	    alevel)))
-	 (methods-cache nil)
-	 (type-cache nil)
-	 (gnus-agent-article-local-times 0)
-	 (archive-method (gnus-server-to-method "archive"))
-	 info group active method cmethod
-	 method-type method-group-list entry)
-    (gnus-message 6 "Checking new news...")
-
-    (while newsrc
-      (setq active (gnus-active (setq group (gnus-info-group
-					     (setq info (pop newsrc))))))
-      ;; First go through all the groups, see what select methods they
-      ;; belong to, and then collect them into lists per unique select
-      ;; method.
-      (if (not (setq method (gnus-info-method info)))
-	  (setq method gnus-select-method)
-	;; There may be several similar methods.  Possibly extend the
-	;; method.
-	(if (setq cmethod (assoc method methods-cache))
-	    (setq method (cdr cmethod))
-	  (setq cmethod (if (stringp method)
-			    (gnus-server-to-method method)
-			  (inline (gnus-find-method-for-group
-				   (gnus-info-group info) info))))
-	  (push (cons method cmethod) methods-cache)
-	  (setq method cmethod)))
-      (setq method-group-list (assoc method type-cache))
-      (unless method-group-list
-	(setq method-type
-	      (cond
-	       ((or (gnus-secondary-method-p method)
-		    (and (gnus-archive-server-wanted-p)
-			 (gnus-methods-equal-p archive-method method)))
-		'secondary)
-	       ((inline (gnus-server-equal gnus-select-method method))
-		'primary)
-	       (t
-		'foreign)))
-	(push (setq method-group-list (list method method-type nil nil))
-	      type-cache))
-      ;; Only add groups that need updating.
-      (if (or (and foreign-level (null (numberp foreign-level)))
-	   (funcall (if one-level #'= #'<=) (gnus-info-level info)
-		    (if (eq (cadr method-group-list) 'foreign)
-			foreign-level
-		      alevel)))
-	  (setcar (nthcdr 2 method-group-list)
-		  (cons info (nth 2 method-group-list)))
-	;; The group is inactive, so we nix out the number of unread articles.
-	;; It leads `(gnus-group-unread group)' to return t.  See also
-	;; `gnus-group-prepare-flat'.
-	(unless active
-	  (when (setq entry (gnus-group-entry group))
-	    (setcar entry t)))))
-
-    ;; Sort the methods based so that the primary and secondary
-    ;; methods come first.  This is done for legacy reasons to try to
-    ;; ensure that side-effect behavior doesn't change from previous
-    ;; Gnus versions.
-    (setq type-cache
-	  (sort (nreverse type-cache)
-		(lambda (c1 c2)
-		  (< (gnus-method-rank (cadr c1) (car c1))
-		     (gnus-method-rank (cadr c2) (car c2))))))
-    ;; Go through the list of servers and possibly extend methods that
-    ;; aren't equal (and that need extension; i.e., they are async).
-    (let ((methods nil))
-      (dolist (elem type-cache)
-	(cl-destructuring-bind (method _method-type infos _dummy) elem
-	  (let ((gnus-opened-servers methods))
-	    (when (and (gnus-similar-server-opened method)
-		       (gnus-check-backend-function
-			'retrieve-group-data-early (car method)))
-	      (setq method (gnus-server-extend-method
-			    (gnus-info-group (car infos))
-			    method))
-	      (setcar elem method))
-	    (push (list method 'ok) methods)))))
-
-    ;; If we have primary/secondary select methods, but no groups from
-    ;; them, we still want to issue a retrieval request from them.
-    (unless dont-connect
-      (dolist (method (cons gnus-select-method
-			    gnus-secondary-select-methods))
-	(when (and (not (assoc method type-cache))
-		   (gnus-check-backend-function 'request-list (car method)))
-	  (with-current-buffer nntp-server-buffer
-	    (gnus-read-active-file-1 method nil)))))
-
-    ;; Clear out all the early methods.
-    (dolist (elem type-cache)
-      (cl-destructuring-bind (method _method-type infos _dummy) elem
-	(when (and method
-		   infos
-		   (gnus-check-backend-function
-		    'retrieve-group-data-early (car method))
-		   (not (gnus-method-denied-p method)))
-	  (when (ignore-errors (gnus-get-function method 'open-server))
-	    (unless (gnus-server-opened method)
-	      (gnus-open-server method))
-	    (when (gnus-server-opened method)
-	      ;; Just mark this server as "cleared".
-	      (gnus-retrieve-group-data-early method nil))))))
-
-    ;; Start early async retrieval of data.
-    (let ((done-methods nil)
-	  sanity-spec)
-      (dolist (elem type-cache)
-	(cl-destructuring-bind (method _method-type infos _dummy) elem
-	  (setq sanity-spec (list (car method) (cadr method)))
-	  (when (and method infos
-		     (not (gnus-method-denied-p method)))
-	    ;; If the open-server method doesn't exist, then the method
-	    ;; itself doesn't exist, so we ignore it.
-	    (if (not (ignore-errors (gnus-get-function method 'open-server)))
-		(setq type-cache (delq elem type-cache))
-	      (unless (gnus-server-opened method)
-		(gnus-open-server method))
-	      (when (and
-		     ;; This is a sanity check, so that we never
-		     ;; attempt to start two async requests to the
-		     ;; same server, because that will fail.  This
-		     ;; should never happen, since the methods should
-		     ;; be unique at this point, but apparently it
-		     ;; does happen in the wild with some setups.
-		     (not (member sanity-spec done-methods))
-		     (gnus-server-opened method)
-		     (gnus-check-backend-function
-		      'retrieve-group-data-early (car method)))
-		(push sanity-spec done-methods)
-		(when (gnus-check-backend-function 'request-scan (car method))
-		  (gnus-request-scan nil method))
-		;; Store the token we get back from -early so that we
-		;; can pass it to -finish later.
-		(setcar (nthcdr 3 elem)
-			(gnus-retrieve-group-data-early method infos))))))))
-
-    ;; Do the rest of the retrieval.
-    (dolist (elem type-cache)
-      (cl-destructuring-bind (method _method-type infos early-data) elem
-	(when (and method infos
-		   (not (gnus-method-denied-p method)))
-	  (let ((updatep (gnus-check-backend-function
-			  'request-update-info (car method))))
-	    ;; See if any of the groups from this method require updating.
-	    (gnus-read-active-for-groups method infos early-data)
-	    (dolist (info infos)
-	      (inline (gnus-get-unread-articles-in-group
-		       info (gnus-active (gnus-info-group info))
-		       updatep)))))))
-    (gnus-message 6 "Checking new news...done")))
-
-(defun gnus-method-rank (type method)
-  (cond
-   ;; Get info for virtual groups last.
-   ((eq (car method) 'nnvirtual)
-    200)
-   ((eq type 'primary)
-    1)
-   ;; Compute the rank of the secondary methods based on where they
-   ;; are in the secondary select list.
-   ((eq type 'secondary)
-    (let ((i 2))
-      (cl-block nil
-	(cl-dolist (smethod gnus-secondary-select-methods)
-	  (when (equal method smethod)
-	    (cl-return i))
-	  (cl-incf i))
-	i)))
-   ;; Just say that all foreign groups have the same rank.
-   (t
-    100)))
+  (cl-assert (eq (current-thread) main-thread))
+  (when gnus-background-get-unread-articles
+    (unless (cl-find-if (lambda (timer)
+                          (eq (timer--function timer)
+                              #'gnus-time-out-thread))
+                        timer-list)
+      (run-at-time
+       nil
+       (/ gnus-max-seconds-hold-mutex 2)
+       #'gnus-time-out-thread)))
+  (if-let ((pending (gnus-thread-group-running-p gnus-thread-group)))
+      (gnus-message 3 "gnus-get-unread-articles: %s still running" pending)
+    (let* ((newsrc (cdr gnus-newsrc-alist))
+	   (alevel (or level gnus-activate-level (1+ gnus-level-subscribed)))
+	   (foreign-level
+	    (or
+	     level
+	     (min
+	      (cond ((and gnus-activate-foreign-newsgroups
+			  (not (numberp gnus-activate-foreign-newsgroups)))
+		     (1+ gnus-level-subscribed))
+		    ((numberp gnus-activate-foreign-newsgroups)
+		     gnus-activate-foreign-newsgroups)
+		    (t 0))
+	      alevel)))
+	   (gnus-agent-article-local-times 0)
+	   (archive-method (gnus-server-to-method "archive"))
+           infos-by-method)
+      (gnus-message 6 "Checking new news...")
+      (while newsrc
+        (when-let ((info (pop newsrc))
+                   (group (gnus-info-group info))
+                   (method (gnus-find-method-for-group group info))
+                   (backend (car method)))
+          (if (or (and foreign-level (not (numberp foreign-level)))
+	          (funcall (if one-level #'= #'<=)
+                           (gnus-info-level info)
+		           (if (or (gnus-server-equal gnus-select-method method)
+                                   (gnus-secondary-method-p method)
+		                   (and (gnus-archive-server-wanted-p)
+			                (gnus-methods-equal-p archive-method method)))
+                               alevel
+			     foreign-level)))
+              (push info (alist-get method infos-by-method nil nil #'equal))
+	    ;; The group is inactive, so we nix out the number of unread articles.
+	    ;; It leads `(gnus-group-unread group)' to return t.  See also
+	    ;; `gnus-group-prepare-flat'.
+	    (unless (gnus-active group)
+	      (when-let ((entry (gnus-group-entry group)))
+	        (setcar entry t))))))
+
+      ;; "Extend" means changing "nnimap" to "nnimap+subaccount"
+      (let (methods)
+        (dolist (elem infos-by-method)
+	  (cl-destructuring-bind (method &rest infos) elem
+	    (let ((gnus-opened-servers methods))
+	      (when (and (gnus-similar-server-opened method)
+		         (gnus-check-backend-function
+			  'retrieve-group-data-early (car method)))
+	        (setq method (gnus-server-extend-method
+			      (gnus-info-group (car infos))
+			      method))
+	        (setcar elem method))
+	      (push (list method 'ok) methods)))))
+
+      ;; For methods with no groups to update, we still request-list if supported.
+      (unless dont-connect
+        (dolist (method gnus-select-methods)
+	  (when (and (not (assoc method infos-by-method))
+		     (gnus-check-backend-function 'request-list (car method)))
+	    (with-current-buffer nntp-server-buffer
+	      (gnus-read-active-file-1 method nil)))))
+
+      ;; Must be able to `gnus-open-server'
+      (setq infos-by-method
+            (cl-remove-if-not
+             (lambda (elem)
+               (cl-destructuring-bind (method &rest infos) elem
+                 (and (ignore-errors (gnus-get-function method 'open-server))
+                      (memq (car method) (mapcar #'car gnus-select-methods)))))
+             infos-by-method))
+
+      (let (methods
+            (coda (apply-partially
+                   (lambda (level*)
+                     (gnus-message-with-timestamp "gnus-get-unread-articles: all done")
+                     (when-let ((timer (cl-find-if (lambda (timer)
+                                                     (eq (timer--function timer)
+                                                         #'gnus-time-out-thread))
+                                                   timer-list)))
+                       (cancel-timer timer))
+                     (gnus-group-list-groups level*)
+                     (gnus-run-hooks 'gnus-after-getting-new-news-hook)
+                     (gnus-group-list-groups)
+                     (redisplay t))
+                   (and (numberp level)
+                        (max (or (and (numberp (car gnus-group-list-mode))
+                                      (car gnus-group-list-mode))
+                                 (gnus-group-default-level))
+                             level)))))
+        (mapc (lambda (elem)
+                (cl-destructuring-bind
+                    (method &rest infos
+                            &aux
+                            (backend (car method))
+                            (already-p
+                             (cl-some (apply-partially
+                                       #'gnus-methods-equal-p method)
+                                      methods))
+                            (denied-p (gnus-method-denied-p method))
+                            (scan-p (gnus-check-backend-function 'request-scan backend))
+                            (early-p (gnus-check-backend-function
+                                      'retrieve-group-data-early backend))
+                            (update-p (gnus-check-backend-function
+                                       'request-update-info backend))
+                            commands)
+                    elem
+                  (when (and method infos (not denied-p) (not already-p))
+                    (push method methods)
+                    (gnus-push-end (gnus-chain-arg
+                                    nil
+                                    #'gnus-open-server
+                                    method)
+                                   commands)
+                    (when early-p
+                      (when scan-p
+                        (gnus-push-end (gnus-chain-arg nil #'gnus-request-scan nil method)
+                                       commands))
+                      ;; Store the token we get back from -early so that we
+                      ;; can pass it to -finish later.
+                      (gnus-push-end (gnus-chain-arg
+                                      nil
+                                      #'gnus-retrieve-group-data-early
+                                      method infos)
+                                     commands))
+                    (gnus-push-end (gnus-chain-arg
+                                    t
+                                    #'gnus-read-active-for-groups
+                                    method infos)
+                                   commands)
+                    (gnus-push-end (gnus-chain-arg
+                                    nil
+                                    (lambda (infos* update-p*)
+                                      (mapc (lambda (info)
+                                              (gnus-get-unread-articles-in-group
+                                               info
+                                               (gnus-active (gnus-info-group info))
+                                               update-p*)
+                                              (gnus-group-update-group (gnus-info-group info) t))
+                                            infos*)
+                                      (gnus-message 6 "Checking new news...done"))
+                                    infos update-p)
+                                   commands)
+                    (if gnus-background-get-unread-articles
+                        (progn
+                          (add-function
+                           :before-while (var coda)
+                           (apply-partially
+                            (lambda (thread-group* &rest _args)
+                              "Proceed with CODA if I'm the last one."
+                              (<= (cl-count thread-group*
+                                            (all-threads)
+                                            :test (lambda (s thr)
+                                                    (cl-search s (thread-name thr))))
+                                  1))
+                            gnus-thread-group))
+                          (gnus-push-end (gnus-chain-arg nil coda) commands)
+                          (apply #'gnus-run-thread
+                                 (mapconcat (apply-partially #'format "%s")
+                                            (cl-subseq method 0 (min (length method) 2))
+                                            "-")
+                                 gnus-mutex-get-unread-articles
+                                 gnus-thread-group
+                                 commands))
+                      (let (gnus-run-thread--subresult)
+                        (mapc (lambda (fn)
+                                (setq gnus-run-thread--subresult
+                                      (funcall fn gnus-run-thread--subresult)))
+                              commands))))))
+              infos-by-method)
+        (unless gnus-background-get-unread-articles
+          (funcall coda))))))
 
 (defun gnus-read-active-for-groups (method infos early-data)
   (with-current-buffer nntp-server-buffer
@@ -1776,7 +1833,7 @@ gnus-read-active-for-groups
        early-data
        (gnus-check-backend-function 'finish-retrieve-group-infos (car method))
        (or (not (gnus-agent-method-p method))
-	   (gnus-online method)))
+           (gnus-online method)))
       (gnus-finish-retrieve-group-infos method infos early-data)
       ;; We may have altered the data now, so mark the dribble buffer
       ;; as dirty so that it gets saved.
@@ -1785,12 +1842,12 @@ gnus-read-active-for-groups
      ;; Most backends have -retrieve-groups.
      ((gnus-check-backend-function 'retrieve-groups (car method))
       (when (gnus-check-backend-function 'request-scan (car method))
-	(gnus-request-scan nil method))
+        (gnus-request-scan nil method))
       (let (groups)
-	(gnus-read-active-file-2
-	 (dolist (info infos (nreverse groups))
-	   (push (gnus-group-real-name (gnus-info-group info)) groups))
-	 method)))
+        (gnus-read-active-file-2
+         (dolist (info infos (nreverse groups))
+           (push (gnus-group-real-name (gnus-info-group info)) groups))
+         method)))
      ;; Virtually all backends have -request-list.
      ((gnus-check-backend-function 'request-list (car method))
       (gnus-read-active-file-1 method nil))
@@ -1798,7 +1855,7 @@ gnus-read-active-for-groups
      ;; by one.
      (t
       (dolist (info infos)
-	(gnus-activate-group (gnus-info-group info) t nil method t))))))
+        (gnus-activate-group (gnus-info-group info) t nil method t))))))
 
 (defun gnus-make-hashtable-from-newsrc-alist ()
   "Create a hash table from `gnus-newsrc-alist'.
@@ -1998,10 +2055,12 @@ gnus-read-active-file
 	   (if (and (not not-native)
 		    (gnus-check-server gnus-select-method))
 	       ;; The native server is available.
-	       (cons gnus-select-method gnus-secondary-select-methods)
+               gnus-select-methods
 	     ;; The native server is down, so we just do the
 	     ;; secondary ones.
-	     gnus-secondary-select-methods)
+             (cl-remove-if
+              (lambda (method) (gnus-method-equal method gnus-select-method))
+              gnus-select-methods))
 	   ;; Also read from the archive server.
 	   (when (gnus-archive-server-wanted-p)
 	     (list "archive")))))
@@ -2036,9 +2095,7 @@ gnus-read-active-file-1
     (gnus-message 5 "%s" mesg)
     (when (gnus-check-server method)
       ;; Request that the backend scan its incoming messages.
-      (when (and (or (and gnus-agent
-			  (gnus-online method))
-		     (not gnus-agent))
+      (when (and (or (not gnus-agent) (gnus-online method))
 		 (gnus-check-backend-function 'request-scan (car method)))
 	(gnus-request-scan nil method))
       (cond
@@ -2215,50 +2272,35 @@ gnus-groups-to-gnus-format
 	    (error (remhash group hashtb)))
 	  (forward-line 1))))))
 
-(defun gnus-read-newsrc-file (&optional force)
-  "Read startup file.
-If FORCE is non-nil, the .newsrc file is read."
-  ;; Reset variables that might be defined in the .newsrc.eld file.
-  (let ((variables (remove 'gnus-format-specs gnus-variable-list)))
-    (while variables
-      (set (car variables) nil)
-      (setq variables (cdr variables))))
-  (let* ((newsrc-file gnus-current-startup-file)
-	 (quick-file (concat newsrc-file ".el")))
-    (save-excursion
-      ;; We always load the .newsrc.eld file.  If always contains
-      ;; much information that can not be gotten from the .newsrc
-      ;; file (ticked articles, killed groups, foreign methods, etc.)
-      (gnus-read-newsrc-el-file quick-file)
-
-      (when (and gnus-read-newsrc-file
-		 (file-exists-p gnus-current-startup-file)
-		 (or force
-		     (and (file-newer-than-file-p newsrc-file quick-file)
-			  (file-newer-than-file-p newsrc-file
-						  (concat quick-file "d")))
-		     (not gnus-newsrc-alist)))
-	;; We read the .newsrc file.  Note that if there if a
-	;; .newsrc.eld file exists, it has already been read, and
-	;; the `gnus-newsrc-hashtb' has been created.  While reading
-	;; the .newsrc file, Gnus will only use the information it
-	;; can find there for changing the data already read -
-	;; i. e., reading the .newsrc file will not trash the data
-	;; already read (except for read articles).
-        (gnus-message 5 "Reading %s..." newsrc-file)
-	(with-current-buffer (nnheader-find-file-noselect newsrc-file)
-	  (buffer-disable-undo)
-	  (gnus-newsrc-to-gnus-format)
-	  (kill-buffer (current-buffer))
-	  (gnus-message 5 "Reading %s...done" newsrc-file)))
-
-      ;; Convert old to new.
-      (gnus-convert-old-newsrc)
-      (gnus-clean-old-newsrc))))
-
-(defun gnus-clean-old-newsrc (&optional _force)
-  ;; Currently no cleanups.
-  )
+(defun gnus-read-newsrc-file (&optional _force)
+  (dolist (var (remove 'gnus-format-specs gnus-variable-list))
+    (set var nil))
+  (when (file-exists-p gnus-newsrc-file)
+    (gnus-message 5 "Reading %s..." gnus-newsrc-file)
+    (gnus-load gnus-newsrc-file))
+  (when (and (file-exists-p gnus-dot-newsrc) (not gnus-newsrc-alist))
+    (gnus-message 5 "Reading %s..." gnus-dot-newsrc)
+    (let ((buffer (nnheader-find-file-noselect gnus-dot-newsrc)))
+      (unwind-protect
+          (with-current-buffer buffer
+            (gnus-newsrc-to-gnus-format)
+            (gnus-message 5 "Reading %s...done" gnus-dot-newsrc))
+        (kill-buffer buffer))))
+  (gnus-make-hashtable-from-newsrc-alist)
+  (setq gnus-topic-alist
+	(mapcar
+	 (lambda (elt)
+           (cl-destructuring-bind (topic . groups)
+               elt
+	     (cons topic
+		   (mapcar (lambda (group)
+			     (if (string-match-p "[^[:ascii:]]" group)
+				 (gnus-group-decoded-name group)
+			       group))
+			   groups))))
+	 gnus-topic-alist))
+  (gnus-run-hooks 'gnus-read-newsrc-hook)
+  (gnus-convert-old-newsrc))
 
 (defun gnus-convert-old-newsrc ()
   "Convert old newsrc formats into the current format, if needed."
@@ -2383,43 +2425,6 @@ gnus-killed-assoc
 (defvar gnus-marked-assoc)
 (defvar gnus-newsrc-assoc)
 
-(defun gnus-read-newsrc-el-file (file)
-  (let ((ding-file (concat file "d")))
-    (when (file-exists-p ding-file)
-      ;; We always, always read the .eld file.
-      (gnus-message 5 "Reading %s..." ding-file)
-      (let (gnus-newsrc-assoc)
-	(gnus-load ding-file)
-	;; Older versions of `gnus-format-specs' are no longer valid
-	;; in Oort Gnus 0.01.
-	(let ((version
-	       (and gnus-newsrc-file-version
-		    (gnus-continuum-version gnus-newsrc-file-version))))
-	  (when (or (not version)
-		    (< version 5.090009))
-	    (setq gnus-format-specs gnus-default-format-specs)))
-	(when gnus-newsrc-assoc
-	  (setq gnus-newsrc-alist gnus-newsrc-assoc))))
-    (gnus-make-hashtable-from-newsrc-alist)
-    (when gnus-topic-alist
-      (setq gnus-topic-alist
-	    (mapcar
-	     (lambda (elt)
-	       (cons (car elt)
-		     (mapcar (lambda (g)
-			       (if (string-match-p "[^[:ascii:]]" g)
-				   (gnus-group-decoded-name g)
-				 g))
-			     (cdr elt))))
-	     gnus-topic-alist)))
-    (when (file-newer-than-file-p file ding-file)
-      ;; Old format quick file
-      (gnus-message 5 "Reading %s..." file)
-      ;; The .el file is newer than the .eld file, so we read that one
-      ;; as well.
-      (gnus-read-old-newsrc-el-file file)))
-  (gnus-run-hooks 'gnus-read-newsrc-el-hook))
-
 ;; Parse the old-style quick startup file
 (defun gnus-read-old-newsrc-el-file (file)
   (let (newsrc killed marked group m info)
@@ -2475,19 +2480,9 @@ gnus-read-old-newsrc-el-file
     (setq gnus-newsrc-alist (nreverse gnus-newsrc-alist))
     (gnus-make-hashtable-from-newsrc-alist)))
 
-(defun gnus-make-newsrc-file (file)
-  "Make server dependent file name by catenating FILE and server host name."
-  (let* ((file (expand-file-name file nil))
-	 (real-file (concat file "-" (nth 1 gnus-select-method))))
-    (if (or (file-exists-p real-file)
-	    (file-exists-p (concat real-file ".el"))
-	    (file-exists-p (concat real-file ".eld")))
-	real-file
-      file)))
-
 (defun gnus-newsrc-to-gnus-format ()
-  (setq gnus-newsrc-options "")
-  (setq gnus-newsrc-options-n nil)
+  (setq gnus-newsrc-options ""
+        gnus-newsrc-options-n nil)
 
   (unless gnus-active-hashtb
     (setq gnus-active-hashtb (gnus-make-hashtable 4000)))
@@ -2675,58 +2670,57 @@ gnus-newsrc-to-gnus-format
 ;; groups will be ignored.  Note that "options -n !all rec.all" is very
 ;; different from "options -n rec.all !all".
 (defun gnus-newsrc-parse-options (options)
-  (let (out eol)
-    (save-excursion
-      (gnus-set-work-buffer)
-      (insert (regexp-quote options))
-      ;; First we treat all continuation lines.
-      (goto-char (point-min))
-      (while (re-search-forward "\n[ \t]+" nil t)
-	(replace-match " " t t))
-      ;; Then we transform all "all"s into ".+"s.
-      (goto-char (point-min))
-      (while (re-search-forward "\\ball\\b" nil t)
-	(replace-match ".+" t t))
-      (goto-char (point-min))
-      ;; We remove all other options than the "-n" ones.
-      (while (re-search-forward "[ \t]-[^n][^-]*" nil t)
-	(replace-match " ")
-	(forward-char -1))
-      (goto-char (point-min))
+  (gnus-with-temp-buffer
+    (insert (regexp-quote options))
+    ;; First we treat all continuation lines.
+    (goto-char (point-min))
+    (while (re-search-forward "\n[ \t]+" nil t)
+      (replace-match " " t t))
+    ;; Then we transform all "all"s into ".+"s.
+    (goto-char (point-min))
+    (while (re-search-forward "\\ball\\b" nil t)
+      (replace-match ".+" t t))
+    (goto-char (point-min))
+    ;; We remove all other options than the "-n" ones.
+    (while (re-search-forward "[ \t]-[^n][^-]*" nil t)
+      (replace-match " ")
+      (forward-char -1))
+    (goto-char (point-min))
 
-      ;; We are only interested in "options -n" lines - we
-      ;; ignore the other option lines.
-      (while (re-search-forward "[ \t]-n" nil t)
-	(setq eol
-	      (or (save-excursion
-		    (and (re-search-forward "[ \t]-n" (point-at-eol) t)
-			 (- (point) 2)))
-		  (point-at-eol)))
-	;; Search for all "words"...
-	(while (re-search-forward "[^ \t,\n]+" eol t)
-	  (if (eq (char-after (match-beginning 0)) ?!)
-	      ;; If the word begins with a bang (!), this is a "not"
-	      ;; spec.  We put this spec (minus the bang) and the
-	      ;; symbol `ignore' into the list.
-	      (push (cons (concat
-			   "^" (buffer-substring
-				(1+ (match-beginning 0))
-				(match-end 0))
-			   "\\($\\|\\.\\)")
-			  'ignore)
-		    out)
-	    ;; There was no bang, so this is a "yes" spec.
-	    (push (cons (concat "^" (match-string 0) "\\($\\|\\.\\)")
-			'subscribe)
-		  out))))
-
-      (setq gnus-newsrc-options-n out))))
-
-(eval-and-compile
-  (defalias 'gnus-long-file-names
-    (if (fboundp 'msdos-long-file-names)
-      'msdos-long-file-names
-      (lambda () t))))
+    ;; We are only interested in "options -n" lines - we
+    ;; ignore the other option lines.
+    (setq gnus-newsrc-options-n
+          (let (out)
+            (while (re-search-forward "[ \t]-n" nil t)
+	      ;; Search for all "words"...
+	      (while (re-search-forward
+                      "[^ \t,\n]+"
+                      (or (save-excursion
+		            (and (re-search-forward "[ \t]-n" (point-at-eol) t)
+			         (- (point) 2)))
+		          (point-at-eol))
+                      t)
+	        (if (eq (char-after (match-beginning 0)) ?!)
+	            ;; If the word begins with a bang (!), this is a "not"
+	            ;; spec.  We put this spec (minus the bang) and the
+	            ;; symbol `ignore' into the list.
+	            (push (cons (concat
+			         "^" (buffer-substring
+				      (1+ (match-beginning 0))
+				      (match-end 0))
+			         "\\($\\|\\.\\)")
+			        'ignore)
+		          out)
+	          ;; There was no bang, so this is a "yes" spec.
+	          (push (cons (concat "^" (match-string 0) "\\($\\|\\.\\)")
+			      'subscribe)
+		        out))))
+            out)))
+  (eval-and-compile
+    (defalias 'gnus-long-file-names
+      (if (fboundp 'msdos-long-file-names)
+          'msdos-long-file-names
+        (lambda () t)))))
 
 (defvar gnus-save-newsrc-file-last-timestamp nil)
 (defun gnus-save-newsrc-file (&optional force)
@@ -2734,12 +2728,10 @@ gnus-save-newsrc-file
 Use the group string names in `gnus-group-list' to pull info
 values from `gnus-newsrc-hashtb', and write a new value of
 `gnus-newsrc-alist'."
-  (when (and (or gnus-newsrc-alist gnus-killed-list)
-	     gnus-current-startup-file)
+  (when (or gnus-newsrc-alist gnus-killed-list)
     ;; Save agent range limits for the currently active method.
     (when gnus-agent
       (gnus-agent-save-local force))
-
     (save-excursion
       (if (and (or gnus-use-dribble-file gnus-child)
 	       (not force)
@@ -2750,97 +2742,33 @@ gnus-save-newsrc-file
 	(gnus-run-hooks 'gnus-save-newsrc-hook)
 	(if gnus-child
 	    (gnus-child-save-newsrc)
-	  ;; Save .newsrc only if the select method is an NNTP method.
-	  ;; The .newsrc file is for interoperability with other
-	  ;; newsreaders, so saving non-NNTP groups there doesn't make
-	  ;; much sense.
-	  (when (and gnus-save-newsrc-file
-		     (eq (car (gnus-server-to-method gnus-select-method))
-			 'nntp))
-	    (gnus-message 8 "Saving %s..." gnus-current-startup-file)
-	    (gnus-gnus-to-newsrc-format)
-	    (gnus-message 8 "Saving %s...done" gnus-current-startup-file))
-
-	  ;; Save .newsrc.eld.
-	  (set-buffer (gnus-get-buffer-create " *Gnus-newsrc*"))
-          (setq-local version-control gnus-backup-startup-file)
-	  (setq buffer-file-name
-		(concat gnus-current-startup-file ".eld"))
-	  (setq default-directory (file-name-directory buffer-file-name))
-	  (buffer-disable-undo)
-	  (erase-buffer)
-          (gnus-message 5 "Saving %s.eld..." gnus-current-startup-file)
-
-          ;; Check timestamp of `gnus-current-startup-file'.eld against
-          ;; `gnus-save-newsrc-file-last-timestamp'.
-	  (if (let* ((checkfile (concat gnus-current-startup-file ".eld"))
-		     (mtime (file-attribute-modification-time
-			     (file-attributes checkfile))))
-		(and gnus-save-newsrc-file-last-timestamp
-                     (time-less-p gnus-save-newsrc-file-last-timestamp
-                                  mtime)
+          ;; save .newsrc
+          (when gnus-save-dot-newsrc
+	    (gnus-gnus-to-newsrc-format))
+          ;; save .newsrc.eld
+          (gnus-message 5 "Saving %s..." gnus-newsrc-file)
+          ;; Starting two gnusae inevitably yields this annoying question
+          ;; of whether to save over each other.
+          (let ((mtime (file-attribute-modification-time
+			(file-attributes gnus-newsrc-file))))
+	    (if (and gnus-save-newsrc-file-last-timestamp
+                     (time-less-p gnus-save-newsrc-file-last-timestamp mtime)
 		     (not
 		      (y-or-n-p
                        (format "%s was updated externally after %s, save?"
-                               checkfile
+                               gnus-newsrc-file
                                (format-time-string
-				"%c"
-				gnus-save-newsrc-file-last-timestamp))))))
-              (gnus-message
-	       4 "Didn't save %s: updated externally"
-	       (concat gnus-current-startup-file ".eld"))
-            (if gnus-save-startup-file-via-temp-buffer
-		(let ((coding-system-for-write gnus-ding-file-coding-system)
+			        "%c"
+			        gnus-save-newsrc-file-last-timestamp)))))
+                (gnus-message 4 "Not saving %s" gnus-newsrc-file)
+              (with-temp-file gnus-newsrc-file
+                (let ((coding-system-for-write gnus-ding-file-coding-system)
                       (standard-output (current-buffer)))
-                  (gnus-gnus-to-quick-newsrc-format)
-                  (gnus-run-hooks 'gnus-save-quick-newsrc-hook)
-                  (save-buffer)
-                  (setq gnus-save-newsrc-file-last-timestamp
-			(file-attribute-modification-time
-			 (file-attributes buffer-file-name))))
-              (let ((coding-system-for-write gnus-ding-file-coding-system)
-                    (version-control gnus-backup-startup-file)
-                    (startup-file (concat gnus-current-startup-file ".eld"))
-                    (working-dir (file-name-directory gnus-current-startup-file))
-                    working-file
-                    (i -1))
-		;; Generate the name of a non-existent file.
-		(while (progn (setq working-file
-                                    (format
-                                     (if (and (eq system-type 'ms-dos)
-                                              (not (gnus-long-file-names)))
-					 "%s#%d.tm#" ; MSDOS limits files to 8+3
-				       "%s#tmp#%d")
-                                     working-dir (setq i (1+ i))))
-                              (file-exists-p working-file)))
-
-		(unwind-protect
-		    (with-file-modes (file-modes startup-file)
-                      (gnus-with-output-to-file working-file
-			(gnus-gnus-to-quick-newsrc-format)
-			(gnus-run-hooks 'gnus-save-quick-newsrc-hook))
-
-                      ;; These bindings will mislead the current buffer
-                      ;; into thinking that it is visiting the startup
-                      ;; file.
-                      (let ((buffer-backed-up nil)
-                            (buffer-file-name startup-file)
-			    (file-precious-flag t))
-			;; Backup the current version of the startup file.
-			(backup-buffer)
-
-			;; Replace the existing startup file with the temp file.
-			(rename-file working-file startup-file t)
-			(setq gnus-save-newsrc-file-last-timestamp
-			      (file-attribute-modification-time
-			       (file-attributes startup-file)))))
-                  (condition-case nil
-                      (delete-file working-file)
-                    (file-error nil)))))
-
-	    (gnus-kill-buffer (current-buffer))
-	    (gnus-message
-	     5 "Saving %s.eld...done" gnus-current-startup-file)))
+                  (gnus-gnus-to-quick-newsrc-format)))
+              (setq gnus-save-newsrc-file-last-timestamp
+		    (file-attribute-modification-time
+                     (file-attributes gnus-newsrc-file)))
+	      (gnus-message 5 "Saving %s...done" gnus-newsrc-file))))
 	(gnus-dribble-delete-file)
 	(gnus-group-set-mode-line)))))
 
@@ -2894,7 +2822,7 @@ gnus-gnus-to-quick-newsrc-format
 	   ;; compatible with older versions of Gnus.  At some point,
 	   ;; if/when a new version of Gnus is released, stop doing
 	   ;; this and move the corresponding decode in
-	   ;; `gnus-read-newsrc-el-file' into a conversion routine.
+	   ;; `gnus-read-newsrc-file' into a conversion routine.
 	   (gnus-newsrc-alist
 	    (mapcar (lambda (info)
 		      (cons (encode-coding-string (car info) 'utf-8-emacs)
@@ -2931,13 +2859,15 @@ gnus-strip-killed-list
     (nreverse olist)))
 
 (defun gnus-gnus-to-newsrc-format (&optional foreign-ok)
+  "Save NNTP state into the Usenet .newsrc file.
+We save a .newsrc file for the benefit of other newsreaders, although
+Gnus itself doesn't consult it in most cases."
   (interactive (list (gnus-y-or-n-p "write foreign groups too? ")))
-  ;; Generate and save the .newsrc file.
-  (with-current-buffer (create-file-buffer gnus-current-startup-file)
+  (with-current-buffer (create-file-buffer gnus-dot-newsrc)
     (let ((standard-output (current-buffer))
 	  (groups (delete "dummy.group" (copy-sequence gnus-group-list)))
 	  info ranges range method)
-      (setq buffer-file-name gnus-current-startup-file)
+      (setq buffer-file-name gnus-dot-newsrc)
       (setq default-directory (file-name-directory buffer-file-name))
       (buffer-disable-undo)
       (erase-buffer)
@@ -2949,8 +2879,9 @@ gnus-gnus-to-newsrc-format
 	(setq info (nth 1 (gnus-group-entry g-name)))
 	;; Maybe don't write foreign groups to .newsrc.
 	(when (or (null (setq method (gnus-info-method info)))
-		  (equal method "native")
-		  (inline (gnus-server-equal method gnus-select-method))
+                  (and (stringp method)
+		       (or (equal "native" method)
+                           (eq 'nntp (car (gnus-server-to-method method)))))
                   foreign-ok)
 	  (insert g-name
 		  (if (> (gnus-info-level info) gnus-level-subscribed)
@@ -2981,14 +2912,11 @@ gnus-gnus-to-newsrc-format
       ;; delete the silly thing entirely first.  but this fails to provide
       ;; such niceties as .newsrc~ creation.
       (if gnus-modtime-botch
-	  (delete-file gnus-startup-file)
+	  (delete-file gnus-dot-newsrc)
 	(clear-visited-file-modtime))
-      (gnus-run-hooks 'gnus-save-standard-newsrc-hook)
       (let ((coding-system-for-write 'raw-text))
 	(save-buffer))
       (kill-buffer (current-buffer)))))
-
-
 ;;;
 ;;; Child functions.
 ;;;
@@ -3007,22 +2935,17 @@ 'gnus-slave-mode-hook
 
 (defun gnus-child-save-newsrc ()
   (with-current-buffer gnus-dribble-buffer
-    (with-file-modes (or (ignore-errors
-			   (file-modes
-			    (concat gnus-current-startup-file ".eld")))
+    (with-file-modes (or (ignore-errors (file-modes gnus-newsrc-file))
 			 (default-file-modes))
-      (let ((child-name
-	     (make-temp-file (concat gnus-current-startup-file "-child-"))))
-	(let ((coding-system-for-write gnus-ding-file-coding-system))
-	  (gnus-write-buffer child-name))))))
+      (let ((child-name (make-temp-file (concat gnus-newsrc-file "-child-")))
+            (coding-system-for-write gnus-ding-file-coding-system))
+	(gnus-write-buffer child-name)))))
 
 (defun gnus-parent-read-child-newsrc ()
   (let ((child-files
-	 (directory-files
-	  (file-name-directory gnus-current-startup-file)
+	 (directory-files (file-name-directory gnus-newsrc-file)
 	  t (concat
-	     "^" (regexp-quote
-		  (file-name-nondirectory gnus-current-startup-file))
+	     "^" (regexp-quote (file-name-nondirectory gnus-newsrc-file))
 	     ;; When the obsolete variables like
 	     ;; `gnus-slave-mode-hook' etc are removed, the "slave"
 	     ;; bit of this regexp should also be removed.
@@ -3059,17 +2982,15 @@ gnus-parent-read-child-newsrc
       (gnus-dribble-touch)
       (gnus-message 7 "Reading child newsrcs...done"))))
 
-
 ;;;
 ;;; Group description.
 ;;;
 
 (defun gnus-read-all-descriptions-files ()
-  (let ((methods (cons gnus-select-method
-		       (nconc
-			(when (gnus-archive-server-wanted-p)
-			  (list "archive"))
-			gnus-secondary-select-methods))))
+  (let ((methods (nconc
+                  (when (gnus-archive-server-wanted-p)
+                    (list "archive"))
+                  gnus-select-methods)))
     (while methods
       (gnus-read-descriptions-file (car methods))
       (setq methods (cdr methods)))
diff --git a/lisp/gnus/gnus-sum.el b/lisp/gnus/gnus-sum.el
index bcd76dda29..5dc8b46323 100644
--- a/lisp/gnus/gnus-sum.el
+++ b/lisp/gnus/gnus-sum.el
@@ -64,14 +64,12 @@ gnus-use-article-prefetch
 (require 'gnus-range)
 (require 'gnus-int)
 (require 'gnus-undo)
-(require 'gnus-util)
 (require 'gmm-utils)
 (require 'mm-decode)
 (require 'shr)
 (require 'url)
 (require 'nnoo)
-(eval-when-compile
-  (require 'subr-x))
+(require 'subr-x)
 
 (autoload 'gnus-summary-limit-include-cached "gnus-cache" nil
   '(gnus-summary-mode))
@@ -80,6 +78,7 @@ gnus-use-article-prefetch
 (autoload 'nnselect-article-rsv "nnselect" nil nil)
 (autoload 'nnselect-article-group "nnselect" nil nil)
 (autoload 'gnus-nnselect-group-p "nnselect" nil nil)
+(autoload 'gnus-agent-get-undownloaded-list "gnus-agent")
 
 (defcustom gnus-kill-summary-on-exit t
   "If non-nil, kill the summary buffer when you exit from it.
@@ -827,6 +826,7 @@ gnus-summary-mark-below
 score file."
   :group 'gnus-score-default
   :type 'integer)
+(make-variable-buffer-local 'gnus-summary-mark-below)
 
 (defun gnus-widget-reversible-match (_widget value)
   "Ignoring WIDGET, convert VALUE to internal form.
@@ -982,6 +982,7 @@ gnus-summary-expunge-below
   :group 'gnus-score-default
   :type '(choice (const :tag "off" nil)
 		 integer))
+(make-variable-buffer-local 'gnus-summary-expunge-below)
 
 (defcustom gnus-thread-expunge-below nil
   "All threads that have a total score less than this variable will be expunged.
@@ -993,6 +994,7 @@ gnus-thread-expunge-below
   :group 'gnus-score-default
   :type '(choice (const :tag "off" nil)
 		 integer))
+(make-variable-buffer-local 'gnus-thread-expunge-below)
 
 (defcustom gnus-summary-menu-hook nil
   "Hook run after the creation of the summary mode menu."
@@ -1321,6 +1323,7 @@ gnus-orphan-score
   :group 'gnus-score-default
   :type '(choice (const nil)
 		 integer))
+(make-variable-buffer-local 'gnus-orphan-score)
 
 (defcustom gnus-summary-save-parts-default-mime "image/.*"
   "A regexp to match MIME parts when saving multiple parts of a
@@ -1378,37 +1381,35 @@ gnus-article-emulate-mime
 ;;; Internal variables
 
 (defvar gnus-summary-display-cache nil)
-(defvar gnus-article-mime-handles nil)
-(defvar gnus-article-decoded-p nil)
-(defvar gnus-article-charset nil)
+(defvar-local gnus-article-mime-handles nil)
+(defvar-local gnus-article-decoded-p nil)
+(defvar-local gnus-article-charset nil)
 (defvar gnus-article-ignored-charsets nil)
-(defvar gnus-scores-exclude-files nil)
-(defvar gnus-page-broken nil)
-
-(defvar gnus-original-article nil)
+(defvar-local gnus-scores-exclude-files nil)
 (defvar gnus-article-internal-prepare-hook nil)
-(defvar gnus-newsgroup-process-stack nil)
+(defvar-local gnus-page-broken nil)
+
+(defvar-local gnus-newsgroup-process-stack nil)
 
 (defvar gnus-thread-indent-array nil)
 (defvar gnus-thread-indent-array-level gnus-thread-indent-level)
-(defvar gnus-sort-gathered-threads-function #'gnus-thread-sort-by-number
-  "Function to sort articles within a thread after it has been gathered together.")
+(make-obsolete-variable 'gnus-sort-gathered-threads-function nil "28.1")
 
 (defvar gnus-summary-save-parts-type-history nil)
 (defvar gnus-summary-save-parts-last-directory mm-default-directory)
 
 ;; Avoid highlighting in kill files.
 (defvar gnus-summary-inhibit-highlight nil)
-(defvar gnus-newsgroup-selected-overlay nil)
+(defvar-local gnus-newsgroup-selected-overlay nil)
 (defvar gnus-inhibit-limiting nil)
-(defvar gnus-newsgroup-adaptive-score-file nil)
-(defvar gnus-current-score-file nil)
+(defvar-local gnus-newsgroup-adaptive-score-file nil)
+(defvar-local gnus-current-score-file nil)
 (defvar gnus-current-move-group nil)
 (defvar gnus-current-copy-group nil)
 (defvar gnus-current-crosspost-group nil)
-(defvar gnus-newsgroup-display nil)
+(defvar-local gnus-newsgroup-display nil)
 
-(defvar gnus-newsgroup-dependencies nil
+(defvar-local gnus-newsgroup-dependencies (gnus-make-hashtable)
   "A hash table holding dependencies between messages.")
 ;; Dependencies are held in a tree structure: a list with the root
 ;; message as car, and each immediate child a sublist (perhaps
@@ -1417,9 +1418,9 @@ gnus-newsgroup-dependencies
 ;; dependency table using the message's Message-ID as the key.  The
 ;; root key is the string "none".
 
-(defvar gnus-newsgroup-adaptive nil)
+(defvar-local gnus-newsgroup-adaptive gnus-use-adaptive-scoring)
 (defvar gnus-summary-display-article-function nil)
-(defvar gnus-summary-highlight-line-function nil
+(defvar-local gnus-summary-highlight-line-function nil
   "Function called after highlighting a summary line.")
 
 (defvar gnus-summary-line-format-alist
@@ -1519,208 +1520,126 @@ gnus-last-shell-command
 
 (defvar gnus-newsgroup-agentized nil
   "Locally bound in each summary buffer to indicate if server has been agentized.")
-(defvar gnus-newsgroup-begin nil)
-(defvar gnus-newsgroup-end nil)
-(defvar gnus-newsgroup-last-rmail nil)
-(defvar gnus-newsgroup-last-mail nil)
-(defvar gnus-newsgroup-last-folder nil)
-(defvar gnus-newsgroup-last-file nil)
-(defvar gnus-newsgroup-last-directory nil)
-(defvar gnus-newsgroup-auto-expire nil)
-(defvar gnus-newsgroup-active nil)
-(defvar gnus-newsgroup-highest nil)
-
-(defvar gnus-newsgroup-data nil)
-(defvar gnus-newsgroup-data-reverse nil)
-(defvar gnus-newsgroup-limit nil)
-(defvar gnus-newsgroup-limits nil)
-(defvar gnus-summary-use-undownloaded-faces nil)
-
-(defvar gnus-newsgroup-unreads nil
+(defvar-local gnus-newsgroup-begin nil)
+(defvar-local gnus-newsgroup-end nil)
+(defvar-local gnus-newsgroup-last-rmail nil)
+(defvar-local gnus-newsgroup-last-mail nil)
+(defvar-local gnus-newsgroup-last-folder nil)
+(defvar-local gnus-newsgroup-last-file nil)
+(defvar-local gnus-newsgroup-last-directory nil)
+(defvar-local gnus-newsgroup-auto-expire nil)
+(defvar-local gnus-newsgroup-active nil)
+(defvar-local gnus-newsgroup-highest nil)
+
+(defvar-local gnus-newsgroup-data nil)
+(defvar-local gnus-newsgroup-data-reverse nil)
+(defvar-local gnus-newsgroup-limit nil)
+(defvar-local gnus-newsgroup-limits nil)
+(defvar-local gnus-summary-use-undownloaded-faces nil)
+
+(defvar-local gnus-newsgroup-unreads nil
   "Sorted list of unread articles in the current newsgroup.")
 
-(defvar gnus-newsgroup-unselected nil
+(defvar-local gnus-newsgroup-unselected nil
   "Sorted list of unselected unread articles in the current newsgroup.")
 
-(defvar gnus-newsgroup-reads nil
+(defvar-local gnus-newsgroup-reads nil
   "Alist of read articles and article marks in the current newsgroup.")
 
-(defvar gnus-newsgroup-expunged-tally nil)
+(defvar-local gnus-newsgroup-expunged-tally 0)
 
-(defvar gnus-newsgroup-marked nil
+(defvar-local gnus-newsgroup-marked nil
   "Sorted list of ticked articles in current newsgroup (a subset of unread art).")
 
-(defvar gnus-newsgroup-spam-marked nil
+(defvar-local gnus-newsgroup-spam-marked nil
   "List of ranges of articles that have been marked as spam.")
 
-(defvar gnus-newsgroup-killed nil
+(defvar-local gnus-newsgroup-killed nil
   "List of ranges of articles that have been through the scoring process.")
 
-(defvar gnus-newsgroup-cached nil
+(defvar-local gnus-newsgroup-cached nil
   "Sorted list of articles that come from the article cache.")
 
-(defvar gnus-newsgroup-saved nil
+(defvar-local gnus-newsgroup-saved nil
   "List of articles that have been saved.")
 
-(defvar gnus-newsgroup-kill-headers nil)
+(defvar-local gnus-newsgroup-kill-headers nil)
 
-(defvar gnus-newsgroup-replied nil
+(defvar-local gnus-newsgroup-replied nil
   "List of articles that have been replied to in the current newsgroup.")
 
-(defvar gnus-newsgroup-forwarded nil
+(defvar-local gnus-newsgroup-forwarded nil
   "List of articles that have been forwarded in the current newsgroup.")
 
-(defvar gnus-newsgroup-expirable nil
+(defvar-local gnus-newsgroup-expirable nil
   "Sorted list of articles in the current newsgroup that can be expired.")
 
-(defvar gnus-newsgroup-processable nil
+(defvar-local gnus-newsgroup-processable nil
   "List of articles in the current newsgroup that can be processed.")
 
-(defvar gnus-newsgroup-downloadable nil
+(defvar-local gnus-newsgroup-downloadable nil
   "Sorted list of articles in the current newsgroup that can be processed.")
 
-(defvar gnus-newsgroup-unfetched nil
+(defvar-local gnus-newsgroup-unfetched nil
   "Sorted list of articles in the current newsgroup whose headers have
 not been fetched into the agent.
 
 This list will always be a subset of gnus-newsgroup-undownloaded.")
 
-(defvar gnus-newsgroup-undownloaded nil
+(defvar-local gnus-newsgroup-undownloaded nil
   "List of articles in the current newsgroup that haven't been downloaded.")
 
-(defvar gnus-newsgroup-unsendable nil
+(defvar-local gnus-newsgroup-unsendable nil
   "List of articles in the current newsgroup that won't be sent.")
 
-(defvar gnus-newsgroup-bookmarks nil
+(defvar-local gnus-newsgroup-bookmarks nil
   "List of articles in the current newsgroup that have bookmarks.")
 
-(defvar gnus-newsgroup-dormant nil
+(defvar-local gnus-newsgroup-dormant nil
   "Sorted list of dormant articles in the current newsgroup.")
 
-(defvar gnus-newsgroup-unseen nil
+(defvar-local gnus-newsgroup-unseen nil
   "List of unseen articles in the current newsgroup.")
 
-(defvar gnus-newsgroup-seen nil
+(defvar-local gnus-newsgroup-seen nil
   "Range of seen articles in the current newsgroup.")
 
-(defvar gnus-newsgroup-unexist nil
+(defvar-local gnus-newsgroup-unexist nil
   "Range of unexisting articles in the current newsgroup.")
 
-(defvar gnus-newsgroup-articles nil
+(defvar-local gnus-newsgroup-articles nil
   "List of articles in the current newsgroup.")
 
-(defvar gnus-newsgroup-scored nil
+(defvar-local gnus-newsgroup-scored nil
   "List of scored articles in the current newsgroup.")
 
-(defvar gnus-newsgroup-headers nil
+(defvar-local gnus-newsgroup-headers nil
   "List of article headers in the current newsgroup.")
 
-(defvar gnus-newsgroup-threads nil)
+(defvar-local gnus-newsgroup-threads nil)
 
-(defvar gnus-newsgroup-prepared nil
+(defvar-local gnus-newsgroup-prepared nil
   "Whether the current group has been prepared properly.")
 
-(defvar gnus-newsgroup-ancient nil
+(defvar-local gnus-newsgroup-ancient nil
   "List of `gnus-fetch-old-headers' articles in the current newsgroup.")
 
-(defvar gnus-newsgroup-sparse nil)
+(defvar-local gnus-newsgroup-sparse nil)
 
-(defvar gnus-newsgroup-selection nil)
-
-(defvar gnus-current-article nil)
-(defvar gnus-article-current nil)
-(defvar gnus-current-headers nil)
-(defvar gnus-have-all-headers nil)
-(defvar gnus-last-article nil)
-(defvar gnus-newsgroup-history nil)
-(defvar gnus-newsgroup-charset nil)
+(defvar-local gnus-newsgroup-selection nil)
+(defvar-local gnus-current-article nil)
+(defvar-local gnus-article-current nil)
+(defvar-local gnus-current-headers nil)
+(defvar-local gnus-have-all-headers nil)
+(defvar-local gnus-last-article nil)
+(defvar-local gnus-newsgroup-history nil)
+(defvar-local gnus-newsgroup-charset nil)
 (defvar gnus-newsgroup-ephemeral-charset nil)
 (defvar gnus-newsgroup-ephemeral-ignored-charsets nil)
-
 (defvar gnus-article-before-search nil)
 
-(defvar gnus-summary-local-variables
-  '(gnus-newsgroup-name
-
-    ;; Marks lists
-    gnus-newsgroup-unreads
-    gnus-newsgroup-unselected
-    gnus-newsgroup-marked
-    gnus-newsgroup-spam-marked
-    gnus-newsgroup-reads
-    gnus-newsgroup-saved
-    gnus-newsgroup-replied
-    gnus-newsgroup-forwarded
-    gnus-newsgroup-expirable
-    gnus-newsgroup-killed
-    gnus-newsgroup-unseen
-    gnus-newsgroup-seen
-    gnus-newsgroup-unexist
-    gnus-newsgroup-cached
-    gnus-newsgroup-downloadable
-    gnus-newsgroup-undownloaded
-    gnus-newsgroup-unsendable
-
-    gnus-newsgroup-selection
-
-    gnus-newsgroup-begin gnus-newsgroup-end
-    gnus-newsgroup-last-rmail gnus-newsgroup-last-mail
-    gnus-newsgroup-last-folder gnus-newsgroup-last-file
-    gnus-newsgroup-last-directory
-    gnus-newsgroup-auto-expire
-    gnus-newsgroup-processable
-    gnus-newsgroup-unfetched
-    gnus-newsgroup-articles
-    gnus-newsgroup-bookmarks gnus-newsgroup-dormant
-    gnus-newsgroup-headers gnus-newsgroup-threads
-    gnus-newsgroup-prepared gnus-summary-highlight-line-function
-    gnus-current-article gnus-current-headers gnus-have-all-headers
-    gnus-last-article gnus-article-internal-prepare-hook
-    (gnus-summary-article-delete-hook . global)
-    (gnus-summary-article-move-hook . global)
-    gnus-newsgroup-dependencies gnus-newsgroup-selected-overlay
-    gnus-newsgroup-scored gnus-newsgroup-kill-headers
-    gnus-thread-expunge-below
-    gnus-score-alist gnus-current-score-file
-    (gnus-summary-expunge-below . global)
-    (gnus-summary-mark-below . global)
-    (gnus-orphan-score . global)
-    gnus-newsgroup-active gnus-scores-exclude-files
-    gnus-newsgroup-highest
-    gnus-newsgroup-history gnus-newsgroup-ancient
-    gnus-newsgroup-sparse gnus-newsgroup-process-stack
-    (gnus-newsgroup-adaptive . gnus-use-adaptive-scoring)
-    gnus-newsgroup-adaptive-score-file (gnus-reffed-article-number . -1)
-    (gnus-newsgroup-expunged-tally . 0)
-    gnus-cache-removable-articles
-    gnus-newsgroup-data gnus-newsgroup-data-reverse
-    gnus-newsgroup-limit gnus-newsgroup-limits
-    gnus-newsgroup-charset gnus-newsgroup-display
-    gnus-summary-use-undownloaded-faces)
-  "Variables that are buffer-local to the summary buffers.")
-
-(defvar gnus-newsgroup-variables nil
-  "A list of variables that have separate values in different newsgroups.
-A list of newsgroup (summary buffer) local variables, or cons of
-variables and their default expressions to be evalled (when the default
-values are not nil), that should be made global while the summary buffer
-is active.
-
-Note: The default expressions will be evaluated (using function `eval')
-before assignment to the local variable rather than just assigned to it.
-If the default expression is the symbol `global', that symbol will not
-be evaluated but the global value of the local variable will be used
-instead.
-
-These variables can be used to set variables in the group parameters
-while still allowing them to affect operations done in other buffers.
-For example:
-
-\(setq gnus-newsgroup-variables
-     \\='(message-use-followup-to
-       (gnus-visible-headers .
-	 \"^From:\\\\|^Newsgroups:\\\\|^Subject:\\\\|^Date:\\\\|^To:\")))
-")
+(make-obsolete-variable 'gnus-summary-local-variables nil "28.1")
+(make-obsolete-variable 'gnus-newsgroup-variables nil "28.1")
 
 (eval-when-compile
   ;; Bind features so that require will believe that gnus-sum has
@@ -1850,17 +1769,15 @@ gnus-simplify-buffer-fuzzy
 (defun gnus-simplify-subject-fuzzy (subject)
   "Simplify a subject string fuzzily.
 See `gnus-simplify-buffer-fuzzy' for details."
-  (save-excursion
-    (let ((regexp gnus-simplify-subject-fuzzy-regexp))
-      (gnus-set-work-buffer)
-      (let ((case-fold-search t))
-	;; Remove uninteresting prefixes.
-	(when (and gnus-simplify-ignored-prefixes
-		   (string-match gnus-simplify-ignored-prefixes subject))
-	  (setq subject (substring subject (match-end 0))))
-	(insert subject)
-	(inline (gnus-simplify-buffer-fuzzy regexp))
-	(buffer-string)))))
+  (gnus-with-temp-buffer
+    (let ((case-fold-search t))
+      ;; Remove uninteresting prefixes.
+      (when (and gnus-simplify-ignored-prefixes
+		 (string-match gnus-simplify-ignored-prefixes subject))
+	(setq subject (substring subject (match-end 0))))
+      (insert subject)
+      (gnus-simplify-buffer-fuzzy gnus-simplify-subject-fuzzy-regexp)
+      (buffer-string))))
 
 (defsubst gnus-simplify-subject-fully (subject)
   "Simplify a subject string according to `gnus-summary-gather-subject-limit'."
@@ -3119,11 +3036,6 @@ bookmark-make-record-function

 (defvar bidi-paragraph-direction)
 
-(defvar gnus-summary-mode-group nil
-  "Variable for communication with `gnus-summary-mode'.
-Allows the `gnus-newsgroup-name' local variable to be set before
-the summary mode hooks are run.")
-
 (define-derived-mode gnus-summary-mode gnus-mode "Summary"
   "Major mode for reading articles.
 \\<gnus-summary-mode-map>
@@ -3143,10 +3055,6 @@ gnus-summary-mode
 
 \\{gnus-summary-mode-map}"
   :interactive nil
-  (let ((gnus-summary-local-variables gnus-newsgroup-variables))
-    (gnus-summary-make-local-variables))
-  (gnus-summary-make-local-variables)
-  (setq gnus-newsgroup-name gnus-summary-mode-group)
   (when (gnus-visual-p 'summary-menu 'menu)
     (gnus-summary-make-menu-bar)
     (gnus-summary-make-tool-bar))
@@ -3163,27 +3071,11 @@ gnus-summary-mode
   (make-local-variable 'gnus-summary-line-format-spec)
   (make-local-variable 'gnus-summary-dummy-line-format)
   (make-local-variable 'gnus-summary-dummy-line-format-spec)
-  (make-local-variable 'gnus-summary-mark-positions)
-  (make-local-variable 'gnus-article-buffer)
-  (make-local-variable 'gnus-article-current)
-  (make-local-variable 'gnus-original-article-buffer)
-  (add-hook 'pre-command-hook #'gnus-set-global-variables nil t)
   (mm-enable-multibyte)
   (setq-local bookmark-make-record-function
-              #'gnus-summary-bookmark-make-record))
-
-(defun gnus-summary-make-local-variables ()
-  "Make all the local summary buffer variables."
-  (dolist (local gnus-summary-local-variables)
-    (if (consp local)
-        (let ((global (if (eq (cdr local) 'global)
-                          ;; Copy the global value of the variable.
-                          (symbol-value (car local))
-                        ;; Use the value from the list.
-                        (eval (cdr local) t))))
-          (set (make-local-variable (car local)) global))
-      ;; Simple nil-valued local variable.
-      (set (make-local-variable local) nil))))
+              #'gnus-summary-bookmark-make-record)
+  (setq gnus-summary-buffer (current-buffer))
+  (set-default 'gnus-summary-buffer gnus-summary-buffer))
 
 ;; Summary data functions.
 
@@ -3527,76 +3419,25 @@ gnus-summary-setup-buffer
 This function does all setup work that relies on the specific
 value of GROUP, and puts the buffer in `gnus-summary-mode'.
 
-Returns non-nil if the setup was successful."
-  (let ((buffer (gnus-summary-buffer-name group))
-	(dead-name (concat "*Dead Summary " group "*")))
-    ;; If a dead summary buffer exists, we kill it.
-    (gnus-kill-buffer dead-name)
-    (if (get-buffer buffer)
-	(progn
-	  (set-buffer buffer)
-	  (setq gnus-summary-buffer (current-buffer))
-	  (not gnus-newsgroup-prepared))
-      (set-buffer (gnus-get-buffer-create buffer))
-      (setq gnus-summary-buffer (current-buffer))
-      (let ((gnus-summary-mode-group group))
-       (gnus-summary-mode))
-      (when (gnus-group-quit-config group)
-        (setq-local gnus-single-article-buffer nil))
-      (turn-on-gnus-mailing-list-mode)
-      ;; These functions don't currently depend on GROUP, but might in
-      ;; the future.
-      (gnus-update-format-specifications nil 'summary 'summary-mode 'summary-dummy)
-      (gnus-update-summary-mark-positions)
-      ;; Set any local variables in the group parameters.
-      (gnus-summary-set-local-parameters gnus-newsgroup-name)
-      t)))
-
-(defun gnus-set-global-variables ()
-  "Set the global equivalents of the buffer-local variables.
-They are set to the latest values they had.  These reflect the summary
-buffer that was in action when the last article was fetched."
-  (when (derived-mode-p 'gnus-summary-mode)
-    (setq gnus-summary-buffer (current-buffer))
-    (let ((name gnus-newsgroup-name)
-	  (marked gnus-newsgroup-marked)
-	  (spam gnus-newsgroup-spam-marked)
-	  (unread gnus-newsgroup-unreads)
-	  (headers gnus-current-headers)
-	  (data gnus-newsgroup-data)
-	  (summary gnus-summary-buffer)
-	  (article-buffer gnus-article-buffer)
-	  (original gnus-original-article-buffer)
-	  (gac gnus-article-current)
-	  (reffed gnus-reffed-article-number)
-	  (score-file gnus-current-score-file)
-	  (default-charset gnus-newsgroup-charset)
-	  vlist)
-      (dolist (local gnus-newsgroup-variables)
-        (push (eval (if (consp local) (car local)
-                      local)
-                    t)
-              vlist))
-      (setq vlist (nreverse vlist))
-      (with-temp-buffer
-	(setq gnus-newsgroup-name name
-	      gnus-newsgroup-marked marked
-	      gnus-newsgroup-spam-marked spam
-	      gnus-newsgroup-unreads unread
-	      gnus-current-headers headers
-	      gnus-newsgroup-data data
-	      gnus-article-current gac
-	      gnus-summary-buffer summary
-	      gnus-article-buffer article-buffer
-	      gnus-original-article-buffer original
-	      gnus-reffed-article-number reffed
-	      gnus-current-score-file score-file
-	      gnus-newsgroup-charset default-charset)
-	(dolist (local gnus-newsgroup-variables)
-          (set (if (consp local)
-                   (car local)
-                 local)
-               (pop vlist)))))))
+Return non-nil if caller must prepare the summary buffer."
+  (gnus-kill-buffer (concat "*Dead Summary " group "*")) ;; kill deadened summaries
+  (let ((name (gnus-summary-buffer-name group)))
+    (if (gnus-buffer-live-p name)
+        (with-current-buffer name
+          (not gnus-newsgroup-prepared))
+      (with-current-buffer (gnus-get-buffer-create name)
+        (gnus-summary-mode)
+        (setq gnus-newsgroup-name group)
+        (when (gnus-group-quit-config gnus-newsgroup-name)
+          (set (make-local-variable 'gnus-single-article-buffer) nil))
+        (turn-on-gnus-mailing-list-mode)
+        ;; These functions don't currently depend on GROUP, but might in
+        ;; the future.
+        (gnus-update-format-specifications 'summary 'summary-mode 'summary-dummy)
+        (gnus-update-summary-mark-positions)
+        ;; Set any local variables in the group parameters.
+        (gnus-summary-set-local-parameters gnus-newsgroup-name)
+        t))))
 
 (defun gnus-summary-article-unread-p (article)
   "Say whether ARTICLE is unread or not."
@@ -3619,7 +3460,7 @@ gnus--dummy-mail-header
   (make-full-mail-header 0 "" "" "05 Apr 2001 23:33:09 +0400" "" "" 0 0 "" nil))
 
 (defconst gnus--dummy-data-list
-  (list (gnus-data-make 0 nil nil gnus--dummy-mail-header nil)))
+  (list (gnus-data-make 0 nil 0 gnus--dummy-mail-header nil)))
 
 (defun gnus-make-thread-indent-array (&optional n)
   (when (or n
@@ -3635,63 +3476,57 @@ gnus-make-thread-indent-array
 
 (defun gnus-update-summary-mark-positions ()
   "Compute where the summary marks are to go."
-  (save-excursion
-    (when (gnus-buffer-live-p gnus-summary-buffer)
-      (set-buffer gnus-summary-buffer))
-    (let ((spec gnus-summary-line-format-spec)
-	  pos)
-      (save-excursion
-	(gnus-set-work-buffer)
-	(let ((gnus-tmp-unread ?Z)
-	      (gnus-replied-mark ?Z)
-	      (gnus-score-below-mark ?Z)
-	      (gnus-score-over-mark ?Z)
-	      (gnus-undownloaded-mark ?Z)
-	      (gnus-summary-line-format-spec spec)
-              ;; Make sure `gnus-data-find' finds a dummy element
-              ;; so we don't call gnus-data-<field> accessors on nil.
-              (gnus-newsgroup-data gnus--dummy-data-list)
-	      (gnus-newsgroup-downloadable '(0))
-	      (gnus-visual nil)
-	      case-fold-search ignores)
-	  ;; Here, all marks are bound to Z.
-	  (gnus-summary-insert-line gnus--dummy-mail-header
-				    0 nil t gnus-tmp-unread t nil "" nil 1)
-	  (goto-char (point-min))
-	  ;; Memorize the positions of the same characters as dummy marks.
-	  (while (re-search-forward "[A-D]" nil t)
-	    (push (point) ignores))
-	  (erase-buffer)
-	  ;; We use A-D as dummy marks in order to know column positions
-	  ;; where marks should be inserted.
-	  (setq gnus-tmp-unread ?A
-		gnus-replied-mark ?B
-		gnus-score-below-mark ?C
-		gnus-score-over-mark ?C
-		gnus-undownloaded-mark ?D)
-	  (gnus-summary-insert-line gnus--dummy-mail-header
-				    0 nil t gnus-tmp-unread t nil "" nil 1)
-	  ;; Ignore characters which aren't dummy marks.
-	  (dolist (p ignores)
-	    (delete-region (goto-char (1- p)) p)
-	    (insert ?Z))
-	  (goto-char (point-min))
-	  (setq pos (list (cons 'unread
-				(and (search-forward "A" nil t)
-				     (- (point) (point-min) 1)))))
-	  (goto-char (point-min))
-	  (push (cons 'replied (and (search-forward "B" nil t)
-				    (- (point) (point-min) 1)))
-		pos)
-	  (goto-char (point-min))
-	  (push (cons 'score (and (search-forward "C" nil t)
-				  (- (point) (point-min) 1)))
-		pos)
-	  (goto-char (point-min))
-	  (push (cons 'download (and (search-forward "D" nil t)
-				     (- (point) (point-min) 1)))
-		pos)))
-      (setq gnus-summary-mark-positions pos))))
+  (with-current-buffer gnus-summary-buffer
+    (setq gnus-summary-mark-positions
+          (gnus-with-temp-buffer
+            (let ((gnus-tmp-unread ?Z)
+                  (gnus-replied-mark ?Z)
+                  (gnus-score-below-mark ?Z)
+                  (gnus-score-over-mark ?Z)
+                  (gnus-undownloaded-mark ?Z)
+                  ;; Make sure `gnus-data-find' finds a dummy element
+                  ;; so we don't call gnus-data-<field> accessors on nil.
+                  (gnus-newsgroup-data gnus--dummy-data-list)
+                  (gnus-newsgroup-downloadable '(0))
+                  pos case-fold-search ignores gnus-visual)
+              ;; Here, all marks are bound to Z.
+              (gnus-summary-insert-line gnus--dummy-mail-header
+                                        0 nil t gnus-tmp-unread t nil "" nil 1)
+              (goto-char (point-min))
+              ;; Memorize the positions of the same characters as dummy marks.
+              (while (re-search-forward "[A-D]" nil t)
+                (push (point) ignores))
+              (erase-buffer)
+              ;; We use A-D as dummy marks in order to know column positions
+              ;; where marks should be inserted.
+              (setq gnus-tmp-unread ?A
+                    gnus-replied-mark ?B
+                    gnus-score-below-mark ?C
+                    gnus-score-over-mark ?C
+                    gnus-undownloaded-mark ?D)
+              (gnus-summary-insert-line gnus--dummy-mail-header
+                                        0 nil t gnus-tmp-unread t nil "" nil 1)
+              ;; Ignore characters which aren't dummy marks.
+              (dolist (p ignores)
+                (delete-region (goto-char (1- p)) p)
+                (insert ?Z))
+              (goto-char (point-min))
+              (setq pos (list (cons 'unread
+                                    (and (search-forward "A" nil t)
+                                         (- (point) (point-min) 1)))))
+              (goto-char (point-min))
+              (push (cons 'replied (and (search-forward "B" nil t)
+                                        (- (point) (point-min) 1)))
+                    pos)
+              (goto-char (point-min))
+              (push (cons 'score (and (search-forward "C" nil t)
+                                      (- (point) (point-min) 1)))
+                    pos)
+              (goto-char (point-min))
+              (push (cons 'download (and (search-forward "D" nil t)
+                                         (- (point) (point-min) 1)))
+                    pos)
+              pos)))))
 
 (defun gnus-summary-insert-dummy-line (subject number)
   "Insert a dummy root in the summary buffer."
@@ -3841,12 +3676,13 @@ gnus-summary-insert-line
     (setq gnus-tmp-lines (if (= gnus-tmp-lines -1)
 	                     "?"
                            (number-to-string gnus-tmp-lines)))
-    (condition-case ()
+    (condition-case err
 	(put-text-property
 	 (point)
 	 (progn (eval gnus-summary-line-format-spec t) (point))
 	 'gnus-number gnus-tmp-number)
-      (error (gnus-message 5 "Error updating the summary line")))
+      (error (gnus-message 3 "Error updating the summary line: %s"
+                           (error-message-string err))))
     (when (gnus-visual-p 'summary-highlight 'highlight)
       (forward-line -1)
       (gnus-summary-highlight-line)
@@ -4030,168 +3866,156 @@ gnus-summary-read-group
 (defun gnus-summary-read-group-1 (group show-all no-article
 					kill-buffer no-display
 					&optional select-articles)
-  "Display articles and threads in a Summary buffer for GROUP."
-  ;; This function calls `gnus-summary-setup-buffer' to create the
-  ;; buffer, put it in `gnus-summary-mode', and set local variables;
-  ;; `gnus-select-newsgroup' to update the group's active and marks
-  ;; from the server; and `gnus-summary-prepare' to actually insert
-  ;; lines for articles.  The rest of the function is mostly concerned
-  ;; with limiting and positioning and windowing and other visual
-  ;; effects.
-
-  ;; Killed foreign groups can't be entered.
-  ;;  (when (and (not (gnus-group-native-p group))
-  ;;	     (not (gethash group gnus-newsrc-hashtb)))
-  ;;    (error "Dead non-native groups can't be entered"))
+  "Display articles and threads in a Summary buffer for GROUP.
+
+Calls `gnus-summary-setup-buffer' to create the
+buffer, put it in `gnus-summary-mode', and set local variables;
+`gnus-select-newsgroup' to update the group's active and marks
+from the server; and `gnus-summary-prepare' to actually insert
+lines for articles.  The rest of the function is mostly concerned
+with limiting and positioning and windowing and other visual
+effects."
   (gnus-message 7 "Retrieving newsgroup: %s..." group)
-  (let* ((new-group (gnus-summary-setup-buffer group))
-	 (quit-config (gnus-group-quit-config group))
-	 (did-select (and new-group (gnus-select-newsgroup
-				     group show-all select-articles))))
-    (cond
-     ;; This summary buffer exists already, so we just select it.
-     ((not new-group)
-      (gnus-set-global-variables)
-      (when kill-buffer
-	(gnus-kill-or-deaden-summary kill-buffer))
-      (gnus-configure-windows 'summary 'force)
-      (gnus-set-mode-line 'summary)
-      (gnus-summary-position-point)
-      (message "")
-      t)
-     ;; We couldn't select this group.
-     ((null did-select)
-      (when (and (derived-mode-p 'gnus-summary-mode)
-		 (not (equal (current-buffer) kill-buffer)))
-	(kill-buffer (current-buffer))
-	(if (not quit-config)
-	    (progn
-	      ;; Update the info -- marks might need to be removed,
-	      ;; for instance.
-	      (gnus-summary-update-info)
-	      (set-buffer gnus-group-buffer)
-	      (gnus-group-jump-to-group group)
-	      (gnus-group-next-unread-group 1))
-	  (gnus-handle-ephemeral-exit quit-config)))
-      (if (null (gnus-list-of-unread-articles group))
-	  (gnus-message 3 "Group %s contains no messages" group)
-	(gnus-message 3 "Can't select group"))
-      nil)
-     ;; The user did a `C-g' while prompting for number of articles,
-     ;; so we exit this group.
-     ((eq did-select 'quit)
-      (and (derived-mode-p 'gnus-summary-mode)
-	   (not (equal (current-buffer) kill-buffer))
-	   (kill-buffer (current-buffer)))
-      (when kill-buffer
-	(gnus-kill-or-deaden-summary kill-buffer))
-      (if (not quit-config)
-	  (progn
-	    (set-buffer gnus-group-buffer)
-	    (gnus-group-jump-to-group group)
-	    (gnus-configure-windows 'group 'force))
-	(gnus-handle-ephemeral-exit quit-config))
-      ;; Finally signal the quit.
-      (signal 'quit nil))
-     ;; The group was successfully selected.
-     (t
-      (gnus-set-global-variables)
-      (when (boundp 'spam-install-hooks)
-	(spam-initialize))
-      ;; Save the active value in effect when the group was entered.
-      (setq gnus-newsgroup-active
-	    (copy-tree
-	     (gnus-active gnus-newsgroup-name)))
-      (setq gnus-newsgroup-highest (cdr gnus-newsgroup-active))
-      ;; You can change the summary buffer in some way with this hook.
-      (gnus-run-hooks 'gnus-select-group-hook)
-      (when (memq 'summary (gnus-update-format-specifications
-			    nil 'summary 'summary-mode 'summary-dummy))
-	;; The format specification for the summary line was updated,
-	;; so we need to update the mark positions as well.
-	(gnus-update-summary-mark-positions))
-      ;; Do score processing.
-      (when gnus-use-scoring
-	(gnus-possibly-score-headers))
-      ;; Check whether to fill in the gaps in the threads.
-      (when gnus-build-sparse-threads
-	(gnus-build-sparse-threads))
-      ;; Find the initial limit.
-      (if show-all
-	  (let ((gnus-newsgroup-dormant nil))
-	    (gnus-summary-initial-limit show-all))
-	(gnus-summary-initial-limit show-all))
-      ;; Generate the summary buffer.
-      (unless no-display
-	(gnus-summary-prepare))
-      (when gnus-use-trees
-	(gnus-tree-open)                ;Autoloaded from gnus-salt.
-        (declare-function gnus-tree-highlight-article "gnus-salt" (article face))
-	(setq gnus-summary-highlight-line-function
-	      #'gnus-tree-highlight-article))
-      ;; If the summary buffer is empty, but there are some low-scored
-      ;; articles or some excluded dormants, we include these in the
-      ;; buffer.
-      (when (and (zerop (buffer-size))
-		 (not no-display))
-	(cond (gnus-newsgroup-dormant
-	       (gnus-summary-limit-include-dormant))
-	      ((and gnus-newsgroup-scored show-all)
-	       (gnus-summary-limit-include-expunged t))))
-      ;; Function `gnus-apply-kill-file' must be called in this hook.
-      (gnus-run-hooks 'gnus-apply-kill-hook)
-      (if (and (zerop (buffer-size))
-	       (not no-display))
-	  (progn
-	    ;; This newsgroup is empty.
-	    (gnus-summary-catchup-and-exit nil t)
-	    (gnus-message 6 "No unread news")
-	    (when kill-buffer
-	      (gnus-kill-or-deaden-summary kill-buffer))
-	    ;; Return nil from this function.
-	    nil)
-	;; Hide conversation thread subtrees.  We cannot do this in
-	;; gnus-summary-prepare-hook since kill processing may not
-	;; work with hidden articles.
-	(gnus-summary-maybe-hide-threads)
-	(gnus-configure-windows 'summary)
-	(when kill-buffer
-	  (gnus-kill-or-deaden-summary kill-buffer))
-	(gnus-summary-auto-select-subject)
-	;; Don't mark any articles as selected if we haven't done that.
-	(when no-article
-	  (setq overlay-arrow-position nil))
-	;; Show first unread article if requested.
-	(if (and (not no-article)
-		 (not no-display)
-		 gnus-newsgroup-unreads
-		 gnus-auto-select-first)
-	    (progn
-	      (let ((art (gnus-summary-article-number)))
-		(when (and art
-			   gnus-plugged
-			   (not (memq art gnus-newsgroup-undownloaded))
-			   (not (memq art gnus-newsgroup-downloadable)))
-		  (gnus-summary-goto-article art))))
-	  ;; Don't select any articles.
-	  (gnus-summary-position-point)
-	  (gnus-configure-windows 'summary 'force)
-	  (gnus-set-mode-line 'summary))
-	(when (and gnus-auto-center-group
-		   (get-buffer-window gnus-group-buffer t))
-	  ;; Gotta use windows, because recenter does weird stuff if
-	  ;; the current buffer ain't the displayed window.
-	  (let ((owin (selected-window)))
-	    (select-window (get-buffer-window gnus-group-buffer t))
-	    (when (gnus-group-goto-group group)
-	      (recenter))
-	    (select-window owin)))
-	;; Mark this buffer as "prepared".
-	(setq gnus-newsgroup-prepared t)
-	(gnus-run-hooks 'gnus-summary-prepared-hook)
-	(unless (gnus-ephemeral-group-p group)
-	  (gnus-group-update-group group nil t))
-	t)))))
+  (unwind-protect
+      (if-let ((prepare-p (gnus-summary-setup-buffer group)))
+          (with-current-buffer (gnus-summary-buffer-name group)
+            (cl-case (gnus-select-newsgroup group show-all select-articles)
+              ('quit
+               ;; The user did a `C-g' while prompting for number of articles,
+               ;; so we exit this group.
+               (and (derived-mode-p 'gnus-summary-mode)
+                    (not (equal (current-buffer) kill-buffer))
+                    (kill-buffer (current-buffer)))
+               (when kill-buffer
+                 (gnus-kill-or-deaden-summary kill-buffer))
+               (if-let ((quit-config (gnus-group-quit-config group)))
+                   (gnus-handle-ephemeral-exit quit-config)
+                 (set-buffer gnus-group-buffer)
+                 (gnus-group-jump-to-group group)
+                 (gnus-configure-windows 'group 'force))
+               ;; Finally signal the quit.
+               (signal 'quit nil))
+              (nil
+               (when (and (derived-mode-p 'gnus-summary-mode)
+                          (not (equal (current-buffer) kill-buffer)))
+                 (kill-buffer (current-buffer))
+                 (if-let ((quit-config (gnus-group-quit-config group)))
+                     (gnus-handle-ephemeral-exit quit-config)
+                   (gnus-summary-update-info) ;; marks might need to be removed
+                   (set-buffer gnus-group-buffer)
+                   (gnus-group-jump-to-group group)
+                   (gnus-group-next-unread-group 1)))
+               (if (null (gnus-list-of-unread-articles group))
+                   (gnus-message 3 "Group %s contains no messages" group)
+                 (gnus-message 3 "Can't select group"))
+               nil)
+              (otherwise
+               ;; The group was successfully selected.
+               (when (boundp 'spam-install-hooks)
+                 (spam-initialize))
+               ;; Save the active value in effect when the group was entered.
+               (setq gnus-newsgroup-active
+                     (copy-tree
+                      (gnus-active gnus-newsgroup-name)))
+               (setq gnus-newsgroup-highest (cdr gnus-newsgroup-active))
+               ;; You can change the summary buffer in some way with this hook.
+               (gnus-run-hooks 'gnus-select-group-hook)
+               (when (memq 'summary (gnus-update-format-specifications
+                                     'summary 'summary-mode 'summary-dummy))
+                 ;; The format specification for the summary line was updated,
+                 ;; so we need to update the mark positions as well.
+                 (gnus-update-summary-mark-positions))
+               ;; Do score processing.
+               (when gnus-use-scoring
+                 (gnus-possibly-score-headers))
+               ;; Check whether to fill in the gaps in the threads.
+               (when gnus-build-sparse-threads
+                 (gnus-build-sparse-threads))
+               ;; Find the initial limit.
+               (if show-all
+                   (let ((gnus-newsgroup-dormant nil))
+                     (gnus-summary-initial-limit show-all))
+                 (gnus-summary-initial-limit show-all))
+               ;; Generate the summary buffer.
+               (unless no-display
+                 (gnus-summary-prepare))
+               (when gnus-use-trees
+                 (gnus-tree-open)            ;Autoloaded from gnus-salt.
+                 (declare-function gnus-tree-highlight-article "gnus-salt" (article face))
+                 (setq gnus-summary-highlight-line-function
+                       #'gnus-tree-highlight-article))
+               ;; If the summary buffer is empty, but there are some low-scored
+               ;; articles or some excluded dormants, we include these in the
+               ;; buffer.
+               (when (and (zerop (buffer-size))
+                          (not no-display))
+                 (cond (gnus-newsgroup-dormant
+                        (gnus-summary-limit-include-dormant))
+                       ((and gnus-newsgroup-scored show-all)
+                        (gnus-summary-limit-include-expunged t))))
+               ;; Function `gnus-apply-kill-file' must be called in this hook.
+               (gnus-run-hooks 'gnus-apply-kill-hook)
+               (if (and (zerop (buffer-size))
+                        (not no-display))
+                   (progn
+                     ;; This newsgroup is empty.
+                     (gnus-summary-catchup-and-exit nil t)
+                     (gnus-message 6 "No unread news")
+                     (when kill-buffer
+                       (gnus-kill-or-deaden-summary kill-buffer))
+                     ;; Return nil from this function.
+                     nil)
+                 ;; Hide conversation thread subtrees.  We cannot do this in
+                 ;; `gnus-summary-prepared-hook' since kill processing may not
+                 ;; work with hidden articles.
+                 (gnus-summary-maybe-hide-threads)
+                 (when kill-buffer
+                   (gnus-kill-or-deaden-summary kill-buffer))
+                 (gnus-summary-auto-select-subject)
+                 ;; Don't mark any articles as selected if we haven't done that.
+                 (when no-article
+                   (setq overlay-arrow-position nil))
+                 ;; Show first unread article if requested.
+                 (if (and (not no-article)
+                          (not no-display)
+                          gnus-newsgroup-unreads
+                          gnus-auto-select-first)
+                     (progn
+                       (let ((art (gnus-summary-article-number)))
+                         (when (and art
+                                    gnus-plugged
+                                    (not (memq art gnus-newsgroup-undownloaded))
+                                    (not (memq art gnus-newsgroup-downloadable)))
+                           (gnus-summary-goto-article art))))
+                   ;; Don't select any articles.
+                   (gnus-summary-position-point)
+                   (gnus-set-mode-line 'summary)
+                   (save-excursion
+                     (gnus-configure-windows 'summary 'force)))
+                 (when (and gnus-auto-center-group
+                            (get-buffer-window gnus-group-buffer t))
+                   ;; Gotta use windows, because recenter does weird stuff if
+                   ;; the current buffer ain't the displayed window.
+                   (let ((owin (selected-window)))
+                     (select-window (get-buffer-window gnus-group-buffer t))
+                     (when (gnus-group-goto-group group)
+                       (recenter))
+                     (select-window owin)))
+                 ;; Mark this buffer as "prepared".
+                 (setq gnus-newsgroup-prepared t)
+                 (gnus-run-hooks 'gnus-summary-prepared-hook)
+                 (unless (gnus-ephemeral-group-p group)
+                   (gnus-group-update-group group nil t))
+                 t))))
+        (with-current-buffer (gnus-summary-buffer-name group)
+          ;; Summary buffer already prepared, so we just select it.
+          (when kill-buffer
+            (gnus-kill-or-deaden-summary kill-buffer))
+          (gnus-set-mode-line 'summary)
+          (gnus-summary-position-point)
+          (gnus-configure-windows 'summary 'force)
+          t))
+    (gnus-message 7 "Retrieving newsgroup: %s...done" group)))
 
 (defun gnus-summary-auto-select-subject ()
   "Select the subject line on initial group entry."
@@ -4225,10 +4049,9 @@ gnus-summary-prepare
     (when gnus-newsgroup-headers
       (gnus-summary-prepare-threads
        (if gnus-show-threads
-	   (gnus-sort-gathered-threads
-	    (funcall gnus-summary-thread-gathering-function
-		     (gnus-sort-threads
-		      (gnus-cut-threads (gnus-make-threads)))))
+	   (gnus-sort-threads
+            (funcall gnus-summary-thread-gathering-function
+                     (gnus-cut-threads (gnus-make-threads))))
 	 ;; Unthreaded display.
 	 (gnus-sort-articles gnus-newsgroup-headers))))
     (setq gnus-newsgroup-data (nreverse gnus-newsgroup-data))
@@ -4317,7 +4140,7 @@ gnus-gather-threads-by-references
     (while threads
       (when (setq references (mail-header-references (caar threads)))
 	(setq id (mail-header-id (caar threads))
-	      ids (inline (gnus-split-references references))
+	      ids (gnus-split-references references)
 	      entered nil)
 	(while (setq ref (pop ids))
 	  (setq ids (delete ref ids))
@@ -4346,16 +4169,6 @@ gnus-gather-threads-by-references
       (setq threads (cdr threads)))
     result))
 
-(defun gnus-sort-gathered-threads (threads)
-  "Sort subthreads inside each gathered thread by `gnus-sort-gathered-threads-function'."
-  (let ((result threads))
-    (while threads
-      (when (stringp (caar threads))
-	(setcdr (car threads)
-		(sort (cdar threads) gnus-sort-gathered-threads-function)))
-      (setq threads (cdr threads)))
-    result))
-
 (defun gnus-thread-loop-p (root thread)
   "Say whether ROOT is in THREAD."
   (let ((stack (list thread))
@@ -4698,33 +4511,42 @@ gnus-summary-update-article-line
            (cdr datal)
            (- (gnus-data-pos data) (gnus-data-pos (cadr datal)) inserted)))))))
 
+(defmacro gnus-summary-assume-in-summary (&rest body)
+  "If we are not in an summary buffer, go there, and execute BODY.  Restore."
+  (declare (indent 0) (debug t))
+  `(save-current-buffer
+     (when (or (derived-mode-p 'gnus-summary-mode)
+               (when (gnus-buffer-live-p gnus-summary-buffer)
+                 (set-buffer gnus-summary-buffer)))
+       ,@body)))
+
 (defun gnus-summary-update-article (article &optional iheader)
   "Update ARTICLE in the summary buffer."
-  (set-buffer gnus-summary-buffer)
-  (let* ((header (gnus-summary-article-header article))
-	 (id (mail-header-id header))
-	 (data (gnus-data-find article))
-	 (thread (gnus-id-to-thread id))
-	 (references (mail-header-references header))
-	 (parent
-	  (gnus-id-to-thread
-	   (or (gnus-parent-id
-		(when (and references
-			   (not (equal "" references)))
-		  references))
-	       "none")))
-	 (inhibit-read-only t)
-	 (old (car thread)))
-    (when thread
-      (unless iheader
-	(setcar thread nil)
-	(when parent
-	  (delq thread parent)))
-      (if (gnus-summary-insert-subject id header)
-	  ;; Set the (possibly) new article number in the data structure.
-	  (setf (gnus-data-number data) (gnus-id-to-article id))
-	(setcar thread old)
-	nil))))
+  (gnus-summary-assume-in-summary
+    (let* ((header (gnus-summary-article-header article))
+           (id (mail-header-id header))
+           (data (gnus-data-find article))
+           (thread (gnus-id-to-thread id))
+           (references (mail-header-references header))
+           (parent
+            (gnus-id-to-thread
+             (or (gnus-parent-id
+                  (when (and references
+                             (not (equal "" references)))
+                    references))
+                 "none")))
+           (inhibit-read-only t)
+           (old (car thread)))
+      (when thread
+        (unless iheader
+          (setcar thread nil)
+          (when parent
+            (delq thread parent)))
+        (if (gnus-summary-insert-subject id header)
+            ;; Set the (possibly) new article number in the data structure.
+            (setf (gnus-data-number data) (gnus-id-to-article id))
+          (setcar thread old)
+          nil)))))
 
 (defun gnus-rebuild-thread (id &optional line)
   "Rebuild the thread containing ID.
@@ -5694,7 +5516,6 @@ gnus-select-newsgroup
 	    gnus-summary-ignore-duplicates))
 	 (info (nth 1 entry))
 	 articles fetched-articles cached)
-
     (unless (gnus-check-server
              (setq-local gnus-current-select-method
                          (gnus-find-method-for-group group)))
@@ -5707,12 +5528,10 @@ gnus-select-newsgroup
 	    (gnus-kill-buffer (current-buffer)))
 	  (error
 	   "Couldn't activate group %s: %s" group (gnus-status-message group))))
-
     (unless (gnus-request-group group t nil info)
       (when (derived-mode-p 'gnus-summary-mode)
 	(gnus-kill-buffer (current-buffer)))
       (error "Couldn't request group %s: %s" group (gnus-status-message group)))
-
     (when (and gnus-agent
 	       (gnus-active group))
       (gnus-agent-possibly-alter-active group (gnus-active group) info)
@@ -5721,11 +5540,9 @@ gnus-select-newsgroup
 	    (gnus-agent-find-parameter
 	     group
 	     'agent-enable-undownloaded-faces)))
-
     (setq gnus-newsgroup-name group
 	  gnus-newsgroup-unselected nil
 	  gnus-newsgroup-unreads (gnus-list-of-unread-articles group))
-
     (let ((display (gnus-group-find-parameter group 'display)))
       (setq gnus-newsgroup-display
 	    (cond
@@ -5758,21 +5575,17 @@ gnus-select-newsgroup
 	      nil))))
 
     (gnus-summary-setup-default-charset)
-
     ;; Kludge to avoid having cached articles nixed out in virtual groups.
     (when (gnus-virtual-group-p group)
       (setq cached gnus-newsgroup-cached))
-
     (setq gnus-newsgroup-unreads
 	  (gnus-sorted-ndifference
 	   (gnus-sorted-ndifference gnus-newsgroup-unreads
 				    gnus-newsgroup-marked)
 	   gnus-newsgroup-dormant))
-
     (setq gnus-newsgroup-processable nil)
 
     (gnus-update-read-articles group gnus-newsgroup-unreads t)
-
     ;; Adjust and set lists of article marks.
     (when info
       (gnus-adjust-marked-articles info))
@@ -5790,11 +5603,7 @@ gnus-select-newsgroup
       ;; Init the dependencies hash table.
       (setq gnus-newsgroup-dependencies
 	    (gnus-make-hashtable (length articles)))
-      (if (gnus-buffer-live-p gnus-group-buffer)
-	  (gnus-set-global-variables)
-	(set-default 'gnus-newsgroup-name gnus-newsgroup-name))
       ;; Retrieve the headers and read them in.
-
       (setq gnus-newsgroup-headers (gnus-fetch-headers articles))
 
       ;; Kludge to avoid having cached articles nixed out in virtual groups.
@@ -5835,9 +5644,11 @@ gnus-select-newsgroup
 	    (and (gnus-group-auto-expirable-p group)
 		 (not (gnus-group-read-only-p group))))
       ;; Set up the article buffer now, if necessary.
-      (unless (and gnus-single-article-buffer
-		   (equal gnus-article-buffer "*Article*"))
-	(gnus-article-setup-buffer))
+      (let ((single-article-p (and gnus-single-article-buffer
+                                   (equal gnus-article-buffer "*Article*"))))
+        (when (and (not single-article-p)
+                   (gnus-buffer-live-p gnus-summary-buffer))))
+      (gnus-article-setup-buffer)
       ;; First and last article in this newsgroup.
       (when gnus-newsgroup-headers
 	(setq gnus-newsgroup-begin
@@ -5859,7 +5670,6 @@ gnus-compute-unseen-list
 (declare-function gnus-get-predicate "gnus-agent" (predicate))
 
 (defun gnus-summary-display-make-predicate (display)
-  (require 'gnus-agent)
   (when (= (length display) 1)
     (setq display (car display)))
   (unless gnus-summary-display-cache
@@ -6032,7 +5842,7 @@ gnus-articles-to-read
 (defun gnus-killed-articles (killed articles)
   (let (out)
     (while articles
-      (when (inline (gnus-member-of-range (car articles) killed))
+      (when (gnus-member-of-range (car articles) killed)
 	(push (car articles) out))
       (setq articles (cdr articles)))
     out))
@@ -6223,8 +6033,8 @@ gnus-update-marks
 
 (defun gnus-set-mode-line (where)
   "Set the mode line of the article or summary buffers.
-If WHERE is `summary', the summary mode line format will be used."
-  ;; Is this mode line one we keep updated?
+If WHERE is `summary', the summary mode line format will be used.
+"
   (when (and (memq where gnus-updated-mode-lines)
 	     (symbol-value
 	      (intern (format "gnus-%s-mode-line-format-spec" where))))
@@ -6471,7 +6281,7 @@ gnus-get-newsgroup-headers-xover
 `nntp-retrieve-headers')."
   ;; Get the Xref when the users reads the articles since most/some
   ;; NNTP servers do not include Xrefs when using XOVER.
-  (setq gnus-article-internal-prepare-hook (list #'gnus-article-get-xrefs))
+  (add-hook 'gnus-article-internal-prepare-hook 'gnus-article-get-xrefs nil t)
   (let ((mail-parse-charset gnus-newsgroup-charset)
 	(mail-parse-ignored-charsets gnus-newsgroup-ignored-charsets)
 	(cur nntp-server-buffer)
@@ -7193,7 +7003,6 @@ gnus-summary-exit
   "Exit reading current newsgroup, and then return to group selection mode.
 `gnus-exit-group-hook' is called with no arguments if that value is non-nil."
   (interactive nil gnus-summary-mode)
-  (gnus-set-global-variables)
   (when (gnus-buffer-live-p gnus-article-buffer)
     (with-current-buffer gnus-article-buffer
       (mm-destroy-parts gnus-article-mime-handles)
@@ -7254,8 +7063,7 @@ gnus-summary-exit
     (gnus-article-stop-animations)
     (unless leave-hidden
       (gnus-configure-windows 'group 'force))
-    (if temporary
-	nil				;Nothing to do.
+    (unless temporary
       (set-buffer buf)
       (if (not gnus-kill-summary-on-exit)
 	  (progn
@@ -7357,17 +7165,14 @@ gnus-handle-ephemeral-exit
     (unless (eq (cdr quit-config) 'group)
       (setq gnus-current-select-method
 	    (gnus-find-method-for-group gnus-newsgroup-name)))
-    (cond ((derived-mode-p 'gnus-summary-mode)
-	   (gnus-set-global-variables))
-	  ((derived-mode-p 'gnus-article-mode)
-	   (save-current-buffer
-	     ;; The `gnus-summary-buffer' variable may point
-	     ;; to the old summary buffer when using a single
-	     ;; article buffer.
-	     (unless (gnus-buffer-live-p gnus-summary-buffer)
-	       (set-buffer gnus-group-buffer))
-	     (set-buffer gnus-summary-buffer)
-	     (gnus-set-global-variables))))
+    (when (derived-mode-p 'gnus-article-mode)
+      (save-current-buffer
+        ;; The `gnus-summary-buffer' variable may point
+        ;; to the old summary buffer when using a single
+        ;; article buffer.
+        (unless (gnus-buffer-live-p gnus-summary-buffer)
+          (set-buffer gnus-group-buffer))
+        (set-buffer gnus-summary-buffer)))
     (if (or (eq (cdr quit-config) 'article)
 	    (eq (cdr quit-config) 'pick))
 	(if (and (boundp 'gnus-pick-mode) (symbol-value 'gnus-pick-mode))
@@ -7670,38 +7475,47 @@ gnus-summary-expand-window
 
 (defun gnus-summary-display-article (article &optional all-header)
   "Display ARTICLE in article buffer."
-  (unless (and (gnus-buffer-live-p gnus-article-buffer)
-	       (with-current-buffer gnus-article-buffer
-		 (derived-mode-p 'gnus-article-mode)))
-    (gnus-article-setup-buffer))
-  (gnus-set-global-variables)
-  (with-current-buffer gnus-article-buffer
-    ;; The buffer may be non-empty and even narrowed, so go back to
-    ;; a sane state.
-    (widen)
-    ;; We're going to erase the buffer anyway so do it now: it can save us from
-    ;; uselessly performing multibyte-conversion of the current content.
-    (let ((inhibit-read-only t)) (erase-buffer))
-    (setq gnus-article-charset gnus-newsgroup-charset)
-    (setq gnus-article-ignored-charsets gnus-newsgroup-ignored-charsets)
-    (mm-enable-multibyte))
-  (if (null article)
-      nil
-    (prog1
-	(funcall (or gnus-summary-display-article-function
-                     #'gnus-article-prepare)
-                 article all-header)
-      (gnus-run-hooks 'gnus-select-article-hook)
-      (when (and gnus-current-article
-		 (not (zerop gnus-current-article)))
-	(gnus-summary-goto-subject gnus-current-article))
-      (gnus-summary-recenter)
-      (when (and gnus-use-trees gnus-show-threads)
-	(gnus-possibly-generate-tree article)
-	(gnus-highlight-selected-tree article))
-      ;; Successfully display article.
-      (gnus-article-set-window-start
-       (cdr (assq article gnus-newsgroup-bookmarks))))))
+  (gnus-summary-assume-in-summary
+    (cl-block nil
+      (let ((result
+             (cond ((not article)
+                    (gnus-message 3 "Article cannot be displayed")
+                    (cl-return))
+                   (gnus-summary-display-article-function
+                    (unless (and (gnus-buffer-live-p gnus-article-buffer)
+                                 (with-current-buffer gnus-article-buffer
+                                   (derived-mode-p 'gnus-article-mode)))
+                      (gnus-article-setup-buffer))
+                    (with-current-buffer gnus-article-buffer
+                      ;; The buffer may be non-empty and even narrowed,
+                      ;; so go back to a sane state.
+                      (widen)
+                      ;; We're going to erase the buffer anyway so do it now:
+                      ;; it can save us from uselessly performing
+                      ;; multibyte-conversion of the current content.
+                      (let ((inhibit-read-only t)) (erase-buffer))
+                      (setq gnus-article-charset gnus-newsgroup-charset)
+                      (setq gnus-article-ignored-charsets
+                            gnus-newsgroup-ignored-charsets)
+                      (mm-enable-multibyte))
+                    (funcall gnus-summary-display-article-function
+                             article all-header))
+                   (t (gnus-article-prepare article all-header)))))
+        (gnus-run-hooks 'gnus-select-article-hook)
+        (when (and gnus-current-article
+                   (not (zerop gnus-current-article)))
+          (gnus-summary-goto-subject gnus-current-article))
+        (gnus-summary-recenter)
+        (when (and gnus-use-trees gnus-show-threads)
+          (gnus-possibly-generate-tree article)
+          (gnus-highlight-selected-tree article))
+        (with-current-buffer gnus-article-buffer
+          (unless gnus-article-decoded-p
+            (mm-disable-multibyte)))
+        ;; Successfully display article.
+        (gnus-article-set-window-start
+         (cdr (assq article gnus-newsgroup-bookmarks)))
+        result))))
 
 (defun gnus-summary-select-article (&optional all-headers force pseudo article)
   "Select the current article.
@@ -7709,50 +7523,40 @@ gnus-summary-select-article
 non-nil, the article will be re-fetched even if it already present in
 the article buffer.  If PSEUDO is non-nil, pseudo-articles will also
 be displayed."
-  ;; Make sure we are in the summary buffer to work around bbdb bug.
-  (unless (derived-mode-p 'gnus-summary-mode)
-    (set-buffer gnus-summary-buffer))
-  (let ((article (or article (gnus-summary-article-number)))
-        (all-headers (and all-headers t)) ; Must be t or nil.
-	gnus-summary-display-article-function)
-    (and (not pseudo)
-	 (gnus-summary-article-pseudo-p article)
-	 (error "This is a pseudo-article"))
-    (with-current-buffer gnus-summary-buffer
+  (gnus-summary-assume-in-summary
+    (let ((article (or article (gnus-summary-article-number)))
+          (all-headers (and all-headers t)) ; Must be t or nil.
+          gnus-summary-display-article-function)
+      (and (not pseudo)
+           (gnus-summary-article-pseudo-p article)
+           (error "This is a pseudo-article"))
       (if (or (and gnus-single-article-buffer
-		   (or (null gnus-current-article)
-		       (null gnus-article-current)
-		       (null (get-buffer gnus-article-buffer))
-		       (not (eq article (cdr gnus-article-current)))
-		       (not (equal (car gnus-article-current)
-				   gnus-newsgroup-name))
-		       (not (get-buffer gnus-original-article-buffer))))
-	      (and (not gnus-single-article-buffer)
-		   (or (null gnus-current-article)
-		       (not (get-buffer gnus-original-article-buffer))
-		       (not (eq gnus-current-article article))))
-	      force)
-	  ;; The requested article is different from the current article.
-	  (progn
-	    (gnus-summary-display-article article all-headers)
-	    (when (gnus-buffer-live-p gnus-article-buffer)
-	      (with-current-buffer gnus-article-buffer
-		(if (not gnus-article-decoded-p) ;; a local variable
-		    (mm-disable-multibyte))))
-	    (gnus-article-set-window-start
-	     (cdr (assq article gnus-newsgroup-bookmarks)))
-	    article)
-	'old))))
+                   (or (null gnus-current-article)
+                       (null gnus-article-current)
+                       (null (get-buffer gnus-article-buffer))
+                       (not (eq article (cdr gnus-article-current)))
+                       (not (equal (car gnus-article-current)
+                                   gnus-newsgroup-name))
+                       (not (get-buffer gnus-original-article-buffer))))
+              (and (not gnus-single-article-buffer)
+                   (or (null gnus-current-article)
+                       (not (get-buffer gnus-original-article-buffer))
+                       (not (eq gnus-current-article article))))
+              force)
+          ;; The requested article is different from the current article.
+          (prog1 article
+            (gnus-summary-display-article article all-headers))
+        'old))))
 
 (defun gnus-summary-force-verify-and-decrypt ()
   "Display buttons for signed/encrypted parts and verify/decrypt them."
   (interactive nil gnus-summary-mode)
   (let ((mm-verify-option 'known)
-	(mm-decrypt-option 'known)
-	(gnus-article-emulate-mime t)
-	(gnus-buttonized-mime-types (append (list "multipart/signed"
-						  "multipart/encrypted")
-					    gnus-buttonized-mime-types)))
+        (mm-decrypt-option 'known)
+        (gnus-article-emulate-mime t)
+        (gnus-buttonized-mime-types (append (list "multipart/signed"
+                                                  "multipart/encrypted")
+                                            gnus-buttonized-mime-types)))
     (gnus-summary-select-article nil 'force)))
 
 (defun gnus-summary-next-article (&optional unread subject backward push)
@@ -7762,68 +7566,67 @@ gnus-summary-next-article
 If BACKWARD, the previous article is selected instead of the next."
   (interactive "P" gnus-summary-mode)
   ;; Make sure we are in the summary buffer.
-  (unless (derived-mode-p 'gnus-summary-mode)
-    (set-buffer gnus-summary-buffer))
-  (cond
-   ;; Is there such an article?
-   ((and (gnus-summary-search-forward unread subject backward)
-	 (or (gnus-summary-display-article (gnus-summary-article-number))
-	     (eq (gnus-summary-article-mark) gnus-canceled-mark)))
-    (gnus-summary-position-point))
-   ;; If not, we try the first unread, if that is wanted.
-   ((and subject
-	 gnus-auto-select-same
-	 (gnus-summary-first-unread-article))
-    (gnus-summary-position-point)
-    (gnus-message 6 "Wrapped"))
-   ;; Try to get next/previous article not displayed in this group.
-   ((and gnus-auto-extend-newsgroup
-	 (not unread) (not subject))
-    (gnus-summary-goto-article
-     (if backward (1- gnus-newsgroup-begin) (1+ gnus-newsgroup-end))
-     nil (count-lines (point-min) (point))))
-   ;; Go to next/previous group.
-   (t
-    (unless (gnus-ephemeral-group-p gnus-newsgroup-name)
-      (gnus-summary-jump-to-group gnus-newsgroup-name))
-    (let ((cmd last-command-event)
-	  (point
-	   (with-current-buffer gnus-group-buffer
-	     (point)))
-	  (current-summary (current-buffer))
-	  (group
-	   (if (eq gnus-keep-same-level 'best)
-	       (gnus-summary-best-group gnus-newsgroup-name)
-	     (gnus-summary-search-group backward gnus-keep-same-level))))
-      ;; Select next unread newsgroup automagically.
-      (cond
-       ((or (not gnus-auto-select-next)
-	    (not cmd))
-	(unless (eq gnus-auto-select-next 'quietly)
-	  (gnus-message 6 "No more%s articles" (if unread " unread" ""))))
-       ((or (eq gnus-auto-select-next 'quietly)
-	    (and (eq gnus-auto-select-next 'slightly-quietly)
-		 push)
-	    (and (eq gnus-auto-select-next 'almost-quietly)
-		 (gnus-summary-last-article-p)))
-	;; Select quietly.
-	(if (gnus-ephemeral-group-p gnus-newsgroup-name)
-	    (gnus-summary-exit)
-	  (unless (eq gnus-auto-select-next 'quietly)
-	    (gnus-message 6 "No more%s articles (%s)..."
-			  (if unread " unread" "")
-			  (if group (concat "selecting " group)
-			    "exiting")))
-	  (gnus-summary-next-group nil group backward)))
-       (t
-	(when (numberp last-input-event)
-	  ;; Somehow or other, we may now have selected a different
-	  ;; window.  Make point go back to the summary buffer.
-	  (when (eq current-summary (current-buffer))
-            ;; FIXME: This burps when get-buffer-window returns nil.
-	    (select-window (get-buffer-window current-summary 0)))
-	  (gnus-summary-walk-group-buffer
-	   gnus-newsgroup-name cmd unread backward point))))))))
+  (gnus-summary-assume-in-summary
+    (cond
+     ;; Is there such an article?
+     ((and (gnus-summary-search-forward unread subject backward)
+           (or (gnus-summary-display-article (gnus-summary-article-number))
+               (eq (gnus-summary-article-mark) gnus-canceled-mark)))
+      (gnus-summary-position-point))
+     ;; If not, we try the first unread, if that is wanted.
+     ((and subject
+           gnus-auto-select-same
+           (gnus-summary-first-unread-article))
+      (gnus-summary-position-point)
+      (gnus-message 6 "Wrapped"))
+     ;; Try to get next/previous article not displayed in this group.
+     ((and gnus-auto-extend-newsgroup
+           (not unread) (not subject))
+      (gnus-summary-goto-article
+       (if backward (1- gnus-newsgroup-begin) (1+ gnus-newsgroup-end))
+       nil (count-lines (point-min) (point))))
+     ;; Go to next/previous group.
+     (t
+      (unless (gnus-ephemeral-group-p gnus-newsgroup-name)
+        (gnus-summary-jump-to-group gnus-newsgroup-name))
+      (let ((cmd last-command-event)
+            (point
+             (with-current-buffer gnus-group-buffer
+               (point)))
+            (current-summary (current-buffer))
+            (group
+             (if (eq gnus-keep-same-level 'best)
+                 (gnus-summary-best-group gnus-newsgroup-name)
+               (gnus-summary-search-group backward gnus-keep-same-level))))
+        ;; Select next unread newsgroup automagically.
+        (cond
+         ((or (not gnus-auto-select-next)
+              (not cmd))
+          (unless (eq gnus-auto-select-next 'quietly)
+            (gnus-message 6 "No more%s articles" (if unread " unread" ""))))
+         ((or (eq gnus-auto-select-next 'quietly)
+              (and (eq gnus-auto-select-next 'slightly-quietly)
+                   push)
+              (and (eq gnus-auto-select-next 'almost-quietly)
+                   (gnus-summary-last-article-p)))
+          ;; Select quietly.
+          (if (gnus-ephemeral-group-p gnus-newsgroup-name)
+              (gnus-summary-exit)
+            (unless (eq gnus-auto-select-next 'quietly)
+              (gnus-message 6 "No more%s articles (%s)..."
+                            (if unread " unread" "")
+                            (if group (concat "selecting " group)
+                              "exiting")))
+            (gnus-summary-next-group nil group backward)))
+         (t
+          (when (numberp last-input-event)
+            ;; Somehow or other, we may now have selected a different
+            ;; window.  Make point go back to the summary buffer.
+            (when (eq current-summary (current-buffer))
+              ;; FIXME: This burps when get-buffer-window returns nil.
+              (select-window (get-buffer-window current-summary 0)))
+            (gnus-summary-walk-group-buffer
+             gnus-newsgroup-name cmd unread backward point)))))))))
 
 (defun gnus-summary-walk-group-buffer (_from-group cmd unread backward start)
   (let ((keystrokes '((?\C-n (gnus-group-next-unread-group 1))
@@ -7909,7 +7712,6 @@ gnus-summary-next-page
 
 Also see the variable `gnus-article-skip-boring'."
   (interactive "P" gnus-summary-mode)
-  (gnus-set-global-variables)
   (let ((article (gnus-summary-article-number))
 	(article-window (get-buffer-window gnus-article-buffer t))
 	endp)
@@ -9333,7 +9135,6 @@ gnus-summary-enter-digest-group
 		     params)
 	    ;; Couldn't select this doc group.
 	    (switch-to-buffer buf)
-	    (gnus-set-global-variables)
 	    (gnus-configure-windows 'summary)
 	    (gnus-message 3 "Article couldn't be entered?"))
 	(kill-buffer dig)))))
@@ -10681,7 +10482,6 @@ gnus-summary-edit-article
     (with-current-buffer gnus-summary-buffer
       (let ((mail-parse-charset gnus-newsgroup-charset)
 	    (mail-parse-ignored-charsets gnus-newsgroup-ignored-charsets))
-	(gnus-set-global-variables)
 	(when (and (not force)
 		   (gnus-group-read-only-p))
 	  (error "The current newsgroup does not support article editing"))
@@ -11591,6 +11391,7 @@ gnus-summary-catchup
 		   gnus-catchup-mark)
 		  (while (gnus-summary-find-next (not all))
 		    (gnus-summary-mark-article-as-read gnus-catchup-mark)))
+
 	      (when (gnus-summary-first-subject (not all))
 		(while (and
 			(if to-here (< (point) to-here) t)
@@ -11639,8 +11440,8 @@ gnus-summary-catchup-and-exit
   (when (gnus-summary-catchup all quietly nil 'fast)
     ;; Select next newsgroup or exit.
     (if (and (not (gnus-group-quit-config gnus-newsgroup-name))
-	     (eq gnus-auto-select-next 'quietly))
-	(gnus-summary-next-group nil)
+             (eq gnus-auto-select-next 'quietly))
+        (gnus-summary-next-group nil)
       (gnus-summary-exit))))
 
 (defun gnus-summary-catchup-all-and-exit (&optional quietly)
@@ -12143,8 +11944,6 @@ gnus-summary-sort
 	      thread
 	    (lambda (t1 t2)
 	       (funcall thread t2 t1))))
-	 (gnus-sort-gathered-threads-function
-	  gnus-thread-sort-functions)
 	 (gnus-article-sort-functions
 	  (if (not reverse)
 	      article
@@ -12881,6 +12680,7 @@ gnus-offer-save-summaries
     (dolist (buffer (buffer-list))
       (when (and (setq buffer (buffer-name buffer))
 		 (string-match "Summary" buffer)
+                 (/= (aref buffer 0) ? )
 		 (with-current-buffer buffer
 		   ;; We check that this is, indeed, a summary buffer.
 		   (and (derived-mode-p 'gnus-summary-mode)
diff --git a/lisp/gnus/gnus-topic.el b/lisp/gnus/gnus-topic.el
index b974dff372..6ba2668e9d 100644
--- a/lisp/gnus/gnus-topic.el
+++ b/lisp/gnus/gnus-topic.el
@@ -25,14 +25,10 @@
 
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
-
 (require 'gnus)
 (require 'gnus-group)
 (require 'gnus-start)
-(require 'gnus-util)
-(eval-when-compile
-  (require 'subr-x))
+(require 'subr-x)
 
 (defgroup gnus-topic nil
   "Group topics."
@@ -428,7 +424,7 @@ gnus-group-prepare-topics
 	 (and gnus-group-listed-groups
 	      (copy-sequence gnus-group-listed-groups))))
 
-    (gnus-update-format-specifications nil 'topic)
+    (gnus-update-format-specifications 'topic)
 
     (when (or (not gnus-topic-alist)
 	      (not gnus-topology-checked-p))
diff --git a/lisp/gnus/gnus-undo.el b/lisp/gnus/gnus-undo.el
index 64ed2bbad6..c7ba39ed24 100644
--- a/lisp/gnus/gnus-undo.el
+++ b/lisp/gnus/gnus-undo.el
@@ -43,7 +43,6 @@
 
 ;;; Code:
 
-(require 'gnus-util)
 (require 'gnus)
 
 (defgroup gnus-undo nil
diff --git a/lisp/gnus/gnus-util.el b/lisp/gnus/gnus-util.el
index be0284515d..d738614584 100644
--- a/lisp/gnus/gnus-util.el
+++ b/lisp/gnus/gnus-util.el
@@ -32,11 +32,10 @@
 
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
-
 (require 'seq)
 (require 'time-date)
 (require 'text-property-search)
+(require 'cl-seq)
 
 (defcustom gnus-completing-read-function 'gnus-emacs-completing-read
   "Function use to do completing read."
@@ -104,6 +103,9 @@ gnus-eval-in-buffer-window
 	     ,@forms)
 	 (select-window ,tempvar)))))
 
+(defmacro gnus-push-end (elt place)
+  `(push ,elt (if (consp ,place) (cdr (last ,place)) ,place)))
+
 (defsubst gnus-goto-char (point)
   (and point (goto-char point)))
 
@@ -547,7 +549,7 @@ gnus-parent-id
   (when (and references
 	     (not (zerop (length references))))
     (if n
-	(let ((ids (inline (gnus-split-references references))))
+	(let ((ids (gnus-split-references references)))
 	  (while (nthcdr n ids)
 	    (setq ids (cdr ids)))
 	  (car ids))
@@ -555,10 +557,12 @@ gnus-parent-id
 	(when (string-match "\\(<[^<]+>\\)[ \t]*\\'" references)
 	  (match-string 1 references))))))
 
-(defsubst gnus-buffer-live-p (buffer)
+(defsubst gnus-buffer-live-p (buffer-or-name)
   "If BUFFER names a live buffer, return its object; else nil."
-  (and buffer (buffer-live-p (setq buffer (get-buffer buffer)))
-       buffer))
+  (when-let* ((buffer-or-name buffer-or-name)
+              (buffer (get-buffer buffer-or-name)))
+    (when (buffer-live-p buffer)
+      buffer)))
 
 (define-obsolete-function-alias 'gnus-buffer-exists-p
   'gnus-buffer-live-p "27.1")
@@ -602,21 +606,7 @@ gnus-copy-file
     (setq to (read-file-name "Copy file to: " default-directory)))
   (copy-file file to))
 
-(defvar gnus-work-buffer " *gnus work*")
-
 (declare-function gnus-get-buffer-create "gnus" (name))
-;; gnus.el requires mm-util.
-(declare-function mm-enable-multibyte "mm-util")
-
-(defun gnus-set-work-buffer ()
-  "Put point in the empty Gnus work buffer."
-  (if (get-buffer gnus-work-buffer)
-      (progn
-	(set-buffer gnus-work-buffer)
-	(erase-buffer))
-    (set-buffer (gnus-get-buffer-create gnus-work-buffer))
-    (kill-all-local-variables)
-    (mm-enable-multibyte)))
 
 (defmacro gnus-group-real-name (group)
   "Find the real name of a foreign newsgroup."
@@ -749,14 +739,7 @@ gnus-delete-file
   (when (file-exists-p file)
     (delete-file file)))
 
-(defun gnus-delete-duplicates (list)
-  "Remove duplicate entries from LIST."
-  (let ((result nil))
-    (while list
-      (unless (member (car list) result)
-	(push (car list) result))
-      (pop list))
-    (nreverse result)))
+(defalias 'gnus-delete-duplicates #'delete-dups)
 
 (defun gnus-delete-directory (directory)
   "Delete files in DIRECTORY.  Subdirectories remain.
@@ -1209,6 +1192,10 @@ gnus-string-equal
        (or (string-equal x y)
 	   (string-equal (downcase x) (downcase y)))))
 
+(defmacro gnus-assign-former-global (var val buffer)
+  "Will rename this."
+  `(setf (buffer-local-value ,var ,buffer) ,val))
+
 (defcustom gnus-use-byte-compile t
   "If non-nil, byte-compile crucial run-time code."
   :type 'boolean
@@ -1676,6 +1663,18 @@ gnus-kill-all-overlays
     (while overlays
       (delete-overlay (pop overlays)))))
 
+(defmacro gnus-with-temp-buffer (&rest forms)
+  "Formerly gnus-set-work-buffer.  Relay buffer-locals to temp buffer."
+  (declare (indent defun))
+  `(let ((gnus-vars (cl-remove-if-not
+                     (lambda (entry)
+                       (zerop (or (cl-search "gnus-" (symbol-name (car entry)))
+                                  -1)))
+                     (buffer-local-variables))))
+     (with-temp-buffer
+       (mapc (lambda (v) (set (make-local-variable (car v)) (cdr v))) gnus-vars)
+       ,@forms)))
+
 (provide 'gnus-util)
 
 ;;; gnus-util.el ends here
diff --git a/lisp/gnus/gnus-uu.el b/lisp/gnus/gnus-uu.el
index ceb2ebcdcb..4a2f957241 100644
--- a/lisp/gnus/gnus-uu.el
+++ b/lisp/gnus/gnus-uu.el
@@ -26,8 +26,6 @@
 
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
-
 (require 'gnus)
 (require 'gnus-art)
 (require 'message)
diff --git a/lisp/gnus/gnus-win.el b/lisp/gnus/gnus-win.el
index 8ac4e39fa5..7a799c1de6 100644
--- a/lisp/gnus/gnus-win.el
+++ b/lisp/gnus/gnus-win.el
@@ -24,11 +24,9 @@
 
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
-
 (require 'gnus)
-(require 'gnus-util)
-(require 'seq)
+
+(declare-function gnus-group-name-at-point "gnus-group")
 
 (defgroup gnus-windows nil
   "Window configuration."
@@ -237,7 +235,28 @@ gnus-window-to-buffer-helper
 	 nil)))
 
 (defun gnus-configure-frame (split &optional window)
-  "Split WINDOW according to SPLIT."
+  "TODO: rewrite `gnus-win.el' to be less opinionated.
+
+It's not ideal to maintain hardcoded maps like `gnus-window-to-buffer'
+and `gnus-buffer-configuration'."
+  (gnus-configure--frame
+   (progn
+     (when-let* ((what (cdr (assq (car split) gnus-window-to-buffer)))
+                 (buf (gnus-window-to-buffer-helper what))
+                 (dead-buf (and (bufferp buf) (not (buffer-live-p buf)))))
+       (if-let* ((live-buf (gnus-buffer-live-p gnus-group-buffer))
+                 (group (with-current-buffer live-buf
+                          (gnus-group-name-at-point))))
+           (setcar split
+                   (gnus-summary-buffer-name group))
+         (error "No group at point")))
+     split)
+   window))
+
+(defun gnus-configure--frame (split &optional window)
+  "Split WINDOW according to SPLIT.
+
+Formerly `gnus-configure-frame'.  Wasn't thread-safe."
   (let* ((current-window (or (get-buffer-window (current-buffer))
                              (selected-window)))
          (window (or window current-window)))
@@ -263,7 +282,7 @@ gnus-configure-frame
        ;; This is a buffer to be selected.
        ((not (memq type '(frame horizontal vertical)))
 	(let ((buffer (cond ((stringp type) type)
-			    (t (cdr (assq type gnus-window-to-buffer))))))
+                            (t (cdr (assq type gnus-window-to-buffer))))))
 	  (unless buffer
 	    (error "Invalid buffer type: %s" type))
 	  (let ((buf (gnus-get-buffer-create
@@ -374,9 +393,7 @@ gnus-frame-split-p
 
 (defun gnus-configure-windows (setting &optional force)
   (cond
-   ((null setting)
-    ;; Do nothing.
-    )
+   ((null setting))
    ((window-configuration-p setting)
     (set-window-configuration setting))
    (t
@@ -403,14 +420,14 @@ gnus-configure-windows
         (unless (gnus-buffer-live-p nntp-server-buffer)
           (nnheader-init-server-buffer))
 
-	;; Remove all 'window-atom parameters, as we're going to blast
-	;; and recreate the window layout.
-	(when (window-parameter nil 'window-atom)
-	  (let ((root (window-atom-root)))
-	    (walk-window-subtree
-	     (lambda (win)
-	       (set-window-parameter win 'window-atom nil))
-	     root t)))
+        ;; Remove all 'window-atom parameters, as we're going to blast
+        ;; and recreate the window layout.
+        (when (window-parameter nil 'window-atom)
+          (let ((root (window-atom-root)))
+            (walk-window-subtree
+             (lambda (win)
+               (set-window-parameter win 'window-atom nil))
+             root t)))
 
         ;; Either remove all windows or just remove all Gnus windows.
         (let ((frame (selected-frame)))
@@ -434,11 +451,11 @@ gnus-configure-windows
           (gnus-configure-frame split)
           (run-hooks 'gnus-configure-windows-hook)
 
-	  ;; If we're using atomic windows, and the current frame has
-	  ;; multiple windows, make them atomic.
-	  (when (and gnus-use-atomic-windows
-		     (window-parent (selected-window)))
-	    (window-make-atom (window-parent (selected-window))))
+          ;; If we're using atomic windows, and the current frame has
+          ;; multiple windows, make them atomic.
+          (when (and gnus-use-atomic-windows
+                     (window-parent (selected-window)))
+            (window-make-atom (window-parent (selected-window))))
 
           (when gnus-window-frame-focus
             (select-frame-set-input-focus
diff --git a/lisp/gnus/gnus.el b/lisp/gnus/gnus.el
index 7dde799a5b..ac252a043b 100644
--- a/lisp/gnus/gnus.el
+++ b/lisp/gnus/gnus.el
@@ -6,7 +6,7 @@
 ;; Author: Masanobu UMEDA <umerin@flab.flab.fujitsu.junet>
 ;;	Lars Magne Ingebrigtsen <larsi@gnus.org>
 ;; Keywords: news, mail
-;; Version: 5.13
+;; Version: 5.14pre
 
 ;; This file is part of GNU Emacs.
 
@@ -29,12 +29,11 @@
 
 (run-hooks 'gnus-load-hook)
 
-(eval-when-compile (require 'cl-lib)
-		   (require 'subr-x))
+(require 'gnus-util)
 (require 'wid-edit)
 (require 'mm-util)
 (require 'nnheader)
-(require 'seq)
+(require 'subr-x)
 
 ;; These are defined afterwards with gnus-define-group-parameter
 (defvar gnus-ham-process-destinations)
@@ -296,7 +295,7 @@ gnus-dbus
   "D-Bus integration for Gnus."
   :group 'gnus)
 
-(defconst gnus-version-number "5.13"
+(defconst gnus-version-number "5.14pre"
   "Version number for this version of Gnus.")
 
 (defconst gnus-version (format "Gnus v%s" gnus-version-number)
@@ -850,9 +849,6 @@ gnus-splash-svg-color-symbols
 
 ;;; Do the rest.
 
-(require 'gnus-util)
-(require 'nnheader)
-
 (defcustom gnus-parameters nil
   "Alist of group parameters.
 
@@ -1024,35 +1020,29 @@ gnus-getenv-nntpserver
 ;; starting or even loading Gnus.
 ;;;###autoload(custom-autoload 'gnus-select-method "gnus")
 
+(defvar gnus-secondary-select-methods)
+(defvar gnus-select-methods)
 (defcustom gnus-select-method
-  (list 'nntp (or (gnus-getenv-nntpserver)
-                  (when (and gnus-default-nntp-server
-                             (not (string= gnus-default-nntp-server "")))
-                    gnus-default-nntp-server)
-                  "news"))
-  "Default method for selecting a newsgroup.
-This variable should be a list, where the first element is how the
-news is to be fetched, the second is the address.
-
-For instance, if you want to get your news via \"flab.flab.edu\" using
-NNTP, you could say:
-
-\(setq gnus-select-method \\='(nntp \"flab.flab.edu\"))
-
-If you want to use your local spool, say:
-
-\(setq gnus-select-method (list \\='nnspool (system-name)))
-
-If you use this variable, you must set `gnus-nntp-server' to nil.
-
-There is a lot more to know about select methods and virtual servers -
-see the manual for details."
-  ;; Emacs has set-after since 22.1.
-  ;set-after '(gnus-default-nntp-server)
+  (if-let ((nntp (or (gnus-getenv-nntpserver)
+                     (unless (zerop (length gnus-default-nntp-server))
+                       gnus-default-nntp-server))))
+      `(nntp ,nntp)
+    '(nnnil ""))
+  "This variable is deprecated in favor of `gnus-select-methods'."
   :group 'gnus-server
   :group 'gnus-start
   :initialize 'custom-initialize-default
+  :set (lambda (symbol value)
+         (set-default symbol value)
+         (setq gnus-select-methods (cons value gnus-secondary-select-methods)))
   :type 'gnus-select-method)
+(make-obsolete-variable 'gnus-select-method 'gnus-select-methods "28.1" 'set)
+(add-variable-watcher
+ 'gnus-select-method
+ (lambda (symbol newval operation _where)
+   (pcase operation
+     ((or 'set 'let 'unlet)
+      (custom-set-variables `(,symbol (quote ,newval)))))))
 
 (defcustom gnus-message-archive-method "archive"
   "Method used for archiving messages you've sent.
@@ -1119,16 +1109,67 @@ gnus-secondary-servers
 (make-obsolete-variable 'gnus-secondary-servers 'gnus-select-method "24.1")
 
 (defcustom gnus-secondary-select-methods nil
-  "A list of secondary methods that will be used for reading news.
-This is a list where each element is a complete select method (see
-`gnus-select-method').
-
-If, for instance, you want to read your mail with the nnml back end,
-you could set this variable:
-
-\(setq gnus-secondary-select-methods \\='((nnml \"\")))"
+  "This variable is deprecated in favor of `gnus-select-methods'."
   :group 'gnus-server
+  :set (lambda (symbol value)
+         (set-default symbol value)
+         (setq gnus-select-methods (cons gnus-select-method value)))
+  :type '(repeat gnus-select-method))
+(make-obsolete-variable 'gnus-secondary-select-methods 'gnus-select-methods "28.1" 'set)
+(add-variable-watcher
+ 'gnus-secondary-select-methods
+ (lambda (symbol newval operation _where)
+   (pcase operation
+     ((or 'set 'let 'unlet)
+      (custom-set-variables `(,symbol (quote ,newval)))))))
+
+(defcustom gnus-select-methods (cons gnus-select-method gnus-secondary-select-methods)
+  "((BACKEND1 SERVER1) (BACKEND2 SERVER2) ... ) where BACKEND is a symbol, e.g.,
+nntp, and SERVER is a string, e.g., \"news.gmane.io\".
+
+For example, these settings specify gmane over nntp, and a home
+dovecot imap server.
+
+Method: nntp
+Server: \"news.gmane.io\"
+
+Method: nnimap
+Server: \"dovecot\"
+Options:
+Variable: nnimap-address
+   Value: \"localhost\"
+Variable: nnimap-stream
+   Value: network
+Variable: nnimap-server-port
+   Value: 143
+Variable: nnimap-inbox
+   Value: \"INBOX\"
+
+Or equivalently,
+
+\(custom-set-variables \\=`(gnus-select-methods
+                        \\='((nntp \"news.gmane.io\")
+                          (nnimap \"dovecot\"
+                           (nnimap-address \"localhost\")
+                           (nnimap-stream network)
+                           (nnimap-server-port 143)
+                           (nnimap-inbox \"INBOX\")))))
+"
+  :group 'gnus-server
+  :initialize 'custom-initialize-default
+  :set (lambda (symbol value)
+         (unless (listp (car value))
+           (setq value (list value)))
+         (set-default symbol value)
+         (setq gnus-select-method (car value))
+         (setq gnus-secondary-select-methods (cdr value)))
   :type '(repeat gnus-select-method))
+(add-variable-watcher
+ 'gnus-select-methods
+ (lambda (symbol newval operation _where)
+   (pcase operation
+     ((or 'set 'let 'unlet)
+      (custom-set-variables `(,symbol (quote ,newval)))))))
 
 (defcustom gnus-local-domain nil
   "Local domain name without a host name.
@@ -1396,7 +1437,7 @@ gnus-redefine-select-method-widget
 				      (intern (car entry))))
 			      gnus-valid-select-methods)
 		    (symbol :tag "other"))
-	    (string :tag "Address")
+	    (string :tag "Server")
 	    (repeat :tag "Options"
 		    :inline t
 		    (list :format "%v"
@@ -2309,8 +2350,8 @@ gnus-agent-method-p-cache
 (defvar gnus-agent-target-move-group-header "X-Gnus-Agent-Move-To")
 (defvar gnus-draft-meta-information-header "X-Draft-From")
 (defvar gnus-group-get-parameter-function #'gnus-group-get-parameter)
-(defvar gnus-original-article-buffer " *Original Article*")
-(defvar gnus-newsgroup-name nil)
+(defvar-local gnus-original-article-buffer " *Original Article*")
+(defvar-local gnus-newsgroup-name nil)
 (defvar gnus-ephemeral-servers nil)
 (defvar gnus-server-method-cache nil)
 (defvar gnus-extended-servers nil)
@@ -2422,8 +2463,8 @@ gnus-info-nodes
     (gnus-tree-mode "(gnus)Tree Display"))
   "Alist of major modes and related Info nodes.")
 
-(defvar gnus-summary-buffer "*Summary*")
-(defvar gnus-article-buffer "*Article*")
+(defvar-local gnus-summary-buffer nil)
+(defvar-local gnus-article-buffer "*Article*")
 (defvar gnus-server-buffer "*Server*")
 
 (defvar gnus-child nil
@@ -2487,7 +2528,7 @@ gnus-moderated-hashtb
 ;; Save window configuration.
 (defvar gnus-prev-winconf nil)
 
-(defvar gnus-reffed-article-number nil)
+(defvar-local gnus-reffed-article-number -1)
 
 (defvar gnus-dead-summary nil)
 
@@ -2956,7 +2997,7 @@ gnus-continuum-version
   "Return VERSION as a floating point number."
   (unless version
     (setq version gnus-version))
-  (when (or (string-match "^\\([^ ]+\\)? ?Gnus v?\\([0-9.]+\\)$" version)
+  (when (or (string-match "^\\([^ ]+\\)? ?Gnus v?\\([0-9.]+\\)\\S-*$" version)
 	    (string-match "^\\(.?\\)gnus-\\([0-9.]+\\)$" version))
     (let ((alpha (and (match-beginning 1) (match-string 1 version)))
 	  (number (match-string 2 version))
@@ -3454,9 +3495,13 @@ gnus-group-prefixed-p
   "Return the prefix of the current group name."
   (< 0 (length (gnus-group-real-prefix group))))
 
-(defun gnus-summary-buffer-name (group)
+(defun gnus-summary-buffer-name (group &optional canonical)
   "Return the summary buffer name of GROUP."
-  (concat "*Summary " group "*"))
+  (let ((name (concat "*Summary " group "*"))
+        (main-thread-p (eq (current-thread) main-thread)))
+    (if (or canonical main-thread-p)
+        name
+      (format " %s %s" (thread-name (current-thread)) name))))
 
 (defun gnus-group-method (group)
   "Return the server or method used for selecting GROUP.
@@ -3490,10 +3535,10 @@ gnus-native-method-p
 (defsubst gnus-secondary-method-p (method)
   "Return whether METHOD is a secondary select method."
   (let ((methods gnus-secondary-select-methods)
-	(gmethod (inline (gnus-server-get-method nil method))))
+	(gmethod (gnus-server-get-method nil method)))
     (while (and methods
 		(not (gnus-method-equal
-		      (inline (gnus-server-get-method nil (car methods)))
+		      (gnus-server-get-method nil (car methods))
 		      gmethod)))
       (setq methods (cdr methods)))
     methods))
@@ -3870,7 +3915,7 @@ gnus-server-extend-method
   ;; "hello", and the select method is ("hello" (my-var "something"))
   ;; in the group "alt.alt", this will result in a new virtual server
   ;; called "hello+alt.alt".
-  (if (or (not (inline (gnus-similar-server-opened method)))
+  (if (or (not (gnus-similar-server-opened method))
 	  (not (cddr method)))
       method
     (let ((address-slot
@@ -3942,12 +3987,11 @@ gnus-find-method-for-group
 	    gnus-select-method
 	  (setq method
 		(cond ((stringp method)
-		       (inline (gnus-server-to-method method)))
+		       (gnus-server-to-method method))
 		      ((stringp (cadr method))
 		       (or
-			(inline
-			 (gnus-same-method-different-name method))
-			(inline (gnus-server-extend-method group method))))
+			(gnus-same-method-different-name method)
+			(gnus-server-extend-method group method)))
 		      (t
 		       method)))
 	  (cond ((equal (cadr method) "")
@@ -4026,7 +4070,7 @@ gnus-read-method
      ((assoc method gnus-valid-select-methods)
       (let ((address (if (memq 'prompt-address
 			       (assoc method gnus-valid-select-methods))
-			 (read-string "Address: ")
+			 (read-string "Server: ")
 		       "")))
 	(or (cadr (assoc (format "%s:%s" method address) open-servers))
 	    (list (intern method) address))))
@@ -4160,14 +4204,6 @@ gnus
 startup level.  If ARG is non-nil and not a positive number, Gnus will
 prompt the user for the name of an NNTP server to use."
   (interactive "P")
-  ;; When using the development version of Gnus, load the gnus-load
-  ;; file.
-  (unless (string-match "^Gnus" gnus-version)
-    (load "gnus-load" nil t))
-  (unless (or (byte-code-function-p (symbol-function 'gnus))
-	      (subr-native-elisp-p (symbol-function 'gnus)))
-    (message "You should compile Gnus")
-    (sit-for 2))
   (let ((gnus-action-message-log (list nil)))
     (gnus-1 arg dont-connect child)
     (gnus-final-warning)))
diff --git a/lisp/gnus/legacy-gnus-agent.el b/lisp/gnus/legacy-gnus-agent.el
index 4f800891b2..bc62349c2c 100644
--- a/lisp/gnus/legacy-gnus-agent.el
+++ b/lisp/gnus/legacy-gnus-agent.el
@@ -26,7 +26,6 @@
 
 ;;; Code:
 (require 'gnus-start)
-(require 'gnus-util)
 (require 'gnus-range)
 (require 'gnus-agent)
 
diff --git a/lisp/gnus/message.el b/lisp/gnus/message.el
index 02db38725a..db996e8192 100644
--- a/lisp/gnus/message.el
+++ b/lisp/gnus/message.el
@@ -5119,6 +5119,7 @@ message-insert-canlock
 (autoload 'nnheader-get-report "nnheader")
 
 (declare-function gnus-setup-posting-charset "gnus-msg" (group))
+(declare-function gnus-msg-inherit-variables "gnus-msg" (source-buffer dest-buffer))
 
 (defun message-send-news (&optional arg)
   (require 'gnus-msg)
@@ -6649,8 +6650,7 @@ message-pop-to-buffer
 			       "Message already being composed; erase? ")
 			    (message nil))))
 	    (error "Message being composed")))
-      (funcall (or switch-function 'pop-to-buffer-same-window)
-	       name)
+      (funcall (or switch-function 'pop-to-buffer-same-window) name)
       (set-buffer name))
     (erase-buffer)
     (message-mode)))
@@ -7299,7 +7299,9 @@ message-followup
       (setq subject (concat "Re: " (message-simplify-subject subject)))
       (widen))
 
-    (message-pop-to-buffer (message-buffer-name "followup" from newsgroups))
+    (let ((before-pop (current-buffer)))
+      (message-pop-to-buffer (message-buffer-name "followup" from newsgroups))
+      (gnus-msg-inherit-variables before-pop (current-buffer)))
 
     (setq message-reply-headers
 	  (make-full-mail-header
diff --git a/lisp/gnus/nnfolder.el b/lisp/gnus/nnfolder.el
index 2de5b83a7b..53a7be4cd7 100644
--- a/lisp/gnus/nnfolder.el
+++ b/lisp/gnus/nnfolder.el
@@ -33,7 +33,6 @@
 (require 'nnmail)
 (require 'nnoo)
 (require 'gnus)
-(require 'gnus-util)
 (require 'gnus-range)
 
 ;; FIXME not explicitly used in this file.
diff --git a/lisp/gnus/nnheader.el b/lisp/gnus/nnheader.el
index 708887cb9c..43a86ba8e1 100644
--- a/lisp/gnus/nnheader.el
+++ b/lisp/gnus/nnheader.el
@@ -26,20 +26,13 @@
 
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
-
 (defvar gnus-decode-encoded-word-function)
 (defvar gnus-decode-encoded-address-function)
 (defvar gnus-alter-header-function)
-
 (defvar nnmail-extra-headers)
 (defvar gnus-newsgroup-name)
 (defvar jka-compr-compression-info-list)
 
-;; Requiring `gnus-util' at compile time creates a circular
-;; dependency between nnheader.el and gnus-util.el.
-;;(eval-when-compile (require 'gnus-util))
-
 (require 'mail-utils)
 (require 'mm-util)
 (require 'gnus-util)
@@ -559,11 +552,10 @@ nnheader-callback-function
 
 (autoload 'gnus-get-buffer-create "gnus")
 
-(defun nnheader-init-server-buffer ()
-  "Initialize the Gnus-backend communication buffer."
-  (unless (gnus-buffer-live-p nntp-server-buffer)
-    (setq nntp-server-buffer (gnus-get-buffer-create " *nntpd*")))
-  (with-current-buffer nntp-server-buffer
+(defsubst nnheader-prep-server-buffer (buffer)
+  "Refactor \"setting the table\" of BUFFER for `nnheader-init-server-buffer' and
+`gnus-thread-body'."
+  (with-current-buffer buffer
     (erase-buffer)
     (mm-enable-multibyte)
     (kill-all-local-variables)
@@ -571,6 +563,12 @@ nnheader-init-server-buffer
     (setq-local nntp-process-response nil)
     t))
 
+(defun nnheader-init-server-buffer ()
+  "Initialize the Gnus-backend communication buffer."
+  (unless (gnus-buffer-live-p nntp-server-buffer)
+    (setq nntp-server-buffer (get-buffer-create " *nntpd*")))
+  (nnheader-prep-server-buffer nntp-server-buffer))
+
 ;;; Various functions the backends use.
 
 (defun nnheader-file-error (file)
diff --git a/lisp/gnus/nnimap.el b/lisp/gnus/nnimap.el
index 3e2a202a6c..fe0b79870b 100644
--- a/lisp/gnus/nnimap.el
+++ b/lisp/gnus/nnimap.el
@@ -26,21 +26,37 @@
 
 ;;; Code:
 
-(eval-when-compile
-  (require 'cl-lib)
-  (require 'subr-x))
-
 (require 'nnheader)
-(require 'gnus-util)
 (require 'gnus)
 (require 'nnoo)
 (require 'netrc)
 (require 'utf7)
 (require 'nnmail)
+(require 'cl-seq)
 
 (autoload 'auth-source-forget+ "auth-source")
 (autoload 'auth-source-search "auth-source")
 
+(declare-function x-server-version "xfns.c" (&optional terminal))
+
+(defmacro nnimap-with-context (buffer &rest body)
+  (declare (indent defun))
+  `(with-current-buffer ,buffer ,@body))
+
+(defmacro nnimap-for-process-buffers (b &rest body)
+  (declare (indent defun))
+  `(cl-flet ((match
+              (buf)
+              (let* ((regex* (mapconcat
+                              #'identity
+                              (mapcar #'regexp-quote
+                                      (split-string nnimap--process-buffer-fmt "%s"))
+                              ".*"))
+                     (regex (format "^%s$" regex*)))
+                (string-match-p regex (buffer-name buf)))))
+     (dolist (,b (seq-filter #'match (gnus-buffers)))
+       ,@body)))
+
 (nnoo-declare nnimap)
 
 (defvoo nnimap-address nil
@@ -123,8 +139,6 @@ nnimap-streaming
 Switching this off will make nnimap slower, but it helps with
 some servers.")
 
-(defvoo nnimap-connection-alist nil)
-
 (defvoo nnimap-current-infos nil)
 
 (defvoo nnimap-namespace nil)
@@ -174,7 +188,6 @@ nnimap-process
 (defvar nnimap-status-string "")
 
 (defvar nnimap-keepalive-timer nil)
-(defvar nnimap-process-buffers nil)
 
 (cl-defstruct nnimap
   group process commands capabilities select-result newlinep server
@@ -199,10 +212,29 @@ nnimap-quirks
 
 (defvar nnimap-inhibit-logging nil)
 
+(defconst nnimap--process-buffer-fmt " *nnimap %s*")
+
+(defun nnimap-assert-context (&optional dont-assert)
+  (let ((result (cl-every (lambda (v) (and (boundp v) v))
+                          '(nnimap-address nnimap-server-port))))
+    (prog1 result
+      (unless dont-assert
+        (cl-assert result)))))
+
+(defsubst nnimap-process-buffer-key ()
+  (nnimap-assert-context)
+  (format nnimap--process-buffer-fmt
+          (mapconcat (apply-partially #'format "%s")
+                     (list
+                      (nnoo-current-server 'nnimap)
+                      nnimap-address
+                      nnimap-server-port)
+                     " ")))
+
 (defun nnimap-group-to-imap (group)
   "Convert Gnus group name to IMAP mailbox name."
-  (let* ((inbox (if nnimap-namespace
-                    (substring nnimap-namespace 0 -1) nil)))
+  (let ((inbox (when nnimap-namespace
+                 (substring nnimap-namespace 0 -1))))
     (utf7-encode
      (cond ((or (not inbox)
                 (string-equal group inbox))
@@ -210,10 +242,13 @@ nnimap-group-to-imap
            ((string-prefix-p "#" group)
             (substring group 1))
            (t
-            (concat nnimap-namespace group))) t)))
+            (concat nnimap-namespace group)))
+     t)))
 
-(defun nnimap-buffer ()
-  (nnimap-find-process-buffer nntp-server-buffer))
+(defalias 'nnimap-buffer #'nnimap-process-buffer)
+(defun nnimap-process-buffer ()
+
+  (nnimap-get-process-buffer (nnimap-process-buffer-key)))
 
 (defun nnimap-header-parameters ()
   (let (params)
@@ -233,10 +268,10 @@ nnimap-header-parameters
     (format "%s" (nreverse params))))
 
 (deffoo nnimap-retrieve-headers (articles &optional group server _fetch-old)
-  (with-current-buffer nntp-server-buffer
+  (nnimap-with-context nntp-server-buffer
     (erase-buffer)
     (when (nnimap-change-group group server)
-      (with-current-buffer (nnimap-buffer)
+      (with-current-buffer (nnimap-process-buffer)
 	(erase-buffer)
 	(nnimap-wait-for-response
 	 (nnimap-send-command
@@ -248,8 +283,7 @@ nnimap-retrieve-headers
 	  (error "Server closed connection"))
 	(nnimap-transform-headers)
 	(nnheader-remove-cr-followed-by-lf))
-      (insert-buffer-substring
-       (nnimap-find-process-buffer (current-buffer))))
+      (insert-buffer-substring (nnimap-process-buffer)))
     'headers))
 
 (defun nnimap-transform-headers ()
@@ -366,32 +400,35 @@ nnimap-article-ranges
 	 result))
       (mapconcat #'identity (nreverse result) ",")))))
 
-(deffoo nnimap-open-server (server &optional defs no-reconnect)
-  (if (nnimap-server-opened server)
-      t
-    (unless (assq 'nnimap-address defs)
-      (setq defs (append defs (list (list 'nnimap-address server)))))
-    (nnoo-change-server 'nnimap server defs)
-    (if no-reconnect
-	(nnimap-find-connection nntp-server-buffer)
-      (or (nnimap-find-connection nntp-server-buffer)
-	  (nnimap-open-connection nntp-server-buffer)))))
-
-(defun nnimap-make-process-buffer (buffer)
-  (with-current-buffer
-      (generate-new-buffer (format " *nnimap %s %s %s*"
-				   nnimap-address nnimap-server-port
-                                   buffer))
-    (mm-disable-multibyte)
-    (buffer-disable-undo)
-    (gnus-add-buffer)
-    (setq-local after-change-functions nil) ;FIXME: Why?
-    (setq-local nnimap-object
-                (make-nnimap :server (nnoo-current-server 'nnimap)
-                             :initial-resync 0))
-    (push (list buffer (current-buffer)) nnimap-connection-alist)
-    (push (current-buffer) nnimap-process-buffers)
-    (current-buffer)))
+(deffoo nnimap-open-server (server &optional defs _no-reconnect)
+  "Context switch based on SERVER.
+
+If `nnoo-current-server-p' is false for SERVER,
+`nnoo-change-server' replaces the current context in `nnoo-state-alist'
+with DEFS.  And does so for all parent classes of nnimap.
+
+This imagined necessity of a back-line assoc list called `nnoo-state-alist'
+was of course another \"youthful indiscretion.\"  He just had to augment
+the key of the front-line assoc list to incorporate SERVER."
+  (nnoo-change-server 'nnimap server defs)
+  (nnimap-server-opened server))
+
+(defun nnimap-make-process-buffer (server process-buffer-key)
+  (nnimap-assert-context)
+  (let ((nnimap-vars (cl-remove-if-not
+                      (lambda (entry)
+                        (zerop (or (cl-search "nnimap-" (symbol-name (car entry)))
+                                   -1)))
+                      (buffer-local-variables))))
+    (with-current-buffer (get-buffer-create process-buffer-key t)
+      (prog1 (current-buffer)
+        (mm-disable-multibyte)
+        (buffer-disable-undo)
+        (gnus-add-buffer)
+        (cl-assert (null after-change-functions))
+        (mapc (lambda (v) (set (make-local-variable (car v)) (cdr v))) nnimap-vars)
+        (setq-local nnimap-object (make-nnimap :server server
+                                               :initial-resync 0))))))
 
 (defvar auth-source-creation-prompts)
 
@@ -418,173 +455,172 @@ nnimap-keepalive
   (let ((now (current-time))
         ;; Set this so we don't wait for a response.
         (nnimap-streaming t))
-    (dolist (buffer nnimap-process-buffers)
-      (when (buffer-live-p buffer)
-	(with-current-buffer buffer
-	  (when (and nnimap-object
-		     (nnimap-last-command-time nnimap-object)
-		     (time-less-p
-		      (cdr nnimap-keepalive-intervals)
-		      (time-subtract
-		       now
-		       (nnimap-last-command-time nnimap-object))))
-            (with-local-quit
-              (ignore-errors          ;E.g. "buffer foo has no process".
-                (nnimap-send-command "NOOP")))))))))
-
-(defun nnimap-open-connection (buffer)
-  ;; Be backwards-compatible -- the earlier value of nnimap-stream was
-  ;; `ssl' when nnimap-server-port was nil.  Sort of.
+    (nnimap-for-process-buffers buffer
+      (with-current-buffer buffer
+	(when (and nnimap-object
+		   (nnimap-last-command-time nnimap-object)
+		   (time-less-p
+		    (cdr nnimap-keepalive-intervals)
+		    (time-subtract
+		     now
+		     (nnimap-last-command-time nnimap-object))))
+          (with-local-quit
+            (ignore-errors (nnimap-send-command "NOOP"))))))))
+
+(defun nnimap-open-connection (process-buffer-key)
+  (nnimap-assert-context)
   (when (and nnimap-server-port
 	     (eq nnimap-stream 'undecided))
     (setq nnimap-stream 'ssl))
   (let ((stream
 	 (if (eq nnimap-stream 'undecided)
 	     (cl-loop for type in '(ssl network)
-		   for stream = (let ((nnimap-stream type))
-				  (nnimap-open-connection-1 buffer))
-		   while (eq stream 'no-connect)
-		   finally (return stream))
-	   (nnimap-open-connection-1 buffer))))
-    (if (eq stream 'no-connect)
-	nil
+		      for stream = (let ((nnimap-stream type))
+				     (nnimap-open-connection-1 process-buffer-key))
+		      while (eq stream 'no-connect)
+		      finally (return stream))
+	   (nnimap-open-connection-1 process-buffer-key))))
+    (unless (eq stream 'no-connect)
       stream)))
 
-;; This is only needed for Windows XP or earlier
-(defun nnimap-map-port (port)
-  (declare-function x-server-version "xfns.c" (&optional terminal))
-  (if (and (eq system-type 'windows-nt)
-           (<= (car (x-server-version)) 5)
-           (equal port "imaps"))
-      "993"
-    port))
-
-(defun nnimap-open-connection-1 (buffer)
-  (unless (or nnimap-keepalive-timer
-              (null nnimap-keepalive-intervals))
-    (setq nnimap-keepalive-timer (run-at-time
-                                  (car nnimap-keepalive-intervals)
-                                  (car nnimap-keepalive-intervals)
-				  #'nnimap-keepalive)))
-  (with-current-buffer (nnimap-make-process-buffer buffer)
+(defun nnimap-open-connection-1 (process-buffer-key)
+  (nnimap-assert-context)
+  (setq nnimap-keepalive-timer
+        (or nnimap-keepalive-timer
+            (when nnimap-keepalive-intervals
+              (run-at-time
+               (car nnimap-keepalive-intervals)
+               (car nnimap-keepalive-intervals)
+	       #'nnimap-keepalive))))
+  ;; Assert commit f33a5dc no longer necessary
+  (when (eq system-type 'windows-nt)
+    (cl-assert (> (car (x-server-version)) 5)))
+  (with-current-buffer
+      (nnimap-make-process-buffer
+       (nnoo-current-server 'nnimap)
+       process-buffer-key)
     (let* ((coding-system-for-read 'binary)
 	   (coding-system-for-write 'binary)
 	   (ports
-	    (cond
-	     ((memq nnimap-stream '(network plain starttls))
-	      (nnheader-message 7 "Opening connection to %s..."
-				nnimap-address)
-	      '("imap" "143"))
-	     ((eq nnimap-stream 'shell)
-	      (nnheader-message 7 "Opening connection to %s via shell..."
-				nnimap-address)
-	      '("imap"))
-	     ((memq nnimap-stream '(ssl tls))
-	      (nnheader-message 7 "Opening connection to %s via tls..."
-				nnimap-address)
-	      '("imaps" "imap" "993" "143"))
-	     (t
-	      (error "Unknown stream type: %s" nnimap-stream))))
-           login-result credentials)
-      (when nnimap-server-port
-	(push nnimap-server-port ports))
-      (let* ((stream-list
-	      (open-network-stream
-	       "*nnimap*" (current-buffer) nnimap-address
-	       (nnimap-map-port (car ports))
-	       :type nnimap-stream
-	       :warn-unless-encrypted t
-	       :return-list t
-	       :shell-command nnimap-shell-program
-	       :capability-command "1 CAPABILITY\r\n"
-               :always-query-capabilities t
-	       :end-of-command "\r\n"
-	       :success " OK "
-	       :starttls-function
-	       (lambda (capabilities)
-		 (when (string-match-p "STARTTLS" capabilities)
-		   "1 STARTTLS\r\n"))))
-	     (stream (car stream-list))
-	     (props (cdr stream-list))
-	     (greeting (plist-get props :greeting))
-	     (capabilities (plist-get props :capabilities))
-	     (stream-type (plist-get props :type))
-             (server (nnoo-current-server 'nnimap)))
-	(when (and stream (not (memq (process-status stream) '(open run))))
-	  (setq stream nil))
-
-        (when (eq (process-type stream) 'network)
-          ;; Use TCP-keepalive so that connections that pass through a NAT
-          ;; router don't hang when left idle.
-          (set-network-process-option stream :keepalive t))
-
-	(setf (nnimap-process nnimap-object) stream)
-	(setf (nnimap-stream-type nnimap-object) stream-type)
-	(if (not stream)
-	    (progn
-	      (nnheader-report 'nnimap "Unable to contact %s:%s via %s"
-			       nnimap-address (car ports) nnimap-stream)
-	      'no-connect)
-	  (set-process-query-on-exit-flag stream nil)
-	  (if (not (string-match-p "[*.] \\(OK\\|PREAUTH\\)" greeting))
-	      (nnheader-report 'nnimap "%s" greeting)
-	    ;; Store the greeting (for debugging purposes).
-	    (setf (nnimap-greeting nnimap-object) greeting)
-	    (setf (nnimap-capabilities nnimap-object)
-		  (mapcar #'upcase
-			  (split-string capabilities)))
-	    (unless (string-match-p "[*.] PREAUTH" greeting)
-	      (if (not (setq credentials
-			     (if (eq nnimap-authenticator 'anonymous)
-				 (list "anonymous"
-				       (message-make-address))
-                               ;; Look for the credentials based on
-                               ;; the virtual server name and the address
-                               (nnimap-credentials
-				(gnus-delete-duplicates
-				 (list server nnimap-address))
-                                ports
-                                nnimap-user))))
-		  (setq nnimap-object nil)
-		(let ((nnimap-inhibit-logging t))
-		  (setq login-result
-			(nnimap-login (car credentials) (cadr credentials))))
-		(if (car login-result)
-		    (progn
-		      ;; Save the credentials if a save function exists
-		      ;; (such a function will only be passed if a new
-		      ;; token was created).
-		      (when (functionp (nth 2 credentials))
-			(funcall (nth 2 credentials)))
-		      ;; See if CAPABILITY is set as part of login
-		      ;; response.
-		      (dolist (response (cddr (nnimap-command "CAPABILITY")))
-			(when (string= "CAPABILITY" (upcase (car response)))
-			  (setf (nnimap-capabilities nnimap-object)
-				(mapcar #'upcase (cdr response)))))
-                      (when (and nnimap-use-namespaces
-                                 (nnimap-capability "NAMESPACE"))
-                        (erase-buffer)
-                        (nnimap-wait-for-response (nnimap-send-command "NAMESPACE"))
-                        (let ((response (nnimap-last-response-string)))
-                          (when (string-match
-                                 "^\\*\\W+NAMESPACE\\W+((\"\\([^\"\n]+\\)\"\\W+\"\\(.\\)\"))\\W+"
-                                 response)
-                            (setq nnimap-namespace (match-string 1 response))))))
-                  ;; If the login failed, then forget the credentials
-		  ;; that are now possibly cached.
-		  (dolist (host (list (nnoo-current-server 'nnimap)
-				      nnimap-address))
-		    (dolist (port ports)
-                      (auth-source-forget+ :host host :port port)))
-		  (delete-process (nnimap-process nnimap-object))
-		  (setq nnimap-object nil))))
-	    (when nnimap-object
-	      (when (nnimap-capability "QRESYNC")
-		(nnimap-command "ENABLE QRESYNC"))
-              (nnheader-message 7 "Opening connection to %s...done"
-				nnimap-address)
-	      (nnimap-process nnimap-object))))))))
+            `(,@(when nnimap-server-port (list nnimap-server-port))
+              ,@(cl-remove-if
+                 (apply-partially #'equal nnimap-server-port)
+                 (cond
+	          ((memq nnimap-stream '(network plain starttls))
+	           (nnheader-message 7 "Opening connection to %s..."
+			             nnimap-address)
+	           '("imap" 143))
+	          ((eq nnimap-stream 'shell)
+	           (nnheader-message 7 "Opening connection to %s via shell..."
+			             nnimap-address)
+	           '("imap"))
+	          ((memq nnimap-stream '(ssl tls))
+	           (nnheader-message 7 "Opening connection to %s via tls..."
+			             nnimap-address)
+	           '("imaps" "imap" 993 143))
+	          (t
+	           (error "Unknown stream type: %s" nnimap-stream))))))
+           login-result
+           credentials
+           (stream-list
+	    (open-network-stream
+             (let ((muffs "[ \t\n\r*]+"))
+	       (string-trim process-buffer-key muffs muffs))
+             (current-buffer)
+             nnimap-address
+             (car ports)
+	     :type nnimap-stream
+	     :warn-unless-encrypted t
+	     :return-list t
+	     :shell-command nnimap-shell-program
+	     :capability-command "1 CAPABILITY\r\n"
+             :always-query-capabilities t
+	     :end-of-command "\r\n"
+	     :success " OK "
+	     :starttls-function
+	     (lambda (capabilities)
+	       (when (string-match-p "STARTTLS" capabilities)
+		 "1 STARTTLS\r\n"))))
+	   (stream (car stream-list))
+	   (props (cdr stream-list))
+	   (greeting (plist-get props :greeting))
+	   (capabilities (plist-get props :capabilities))
+	   (stream-type (plist-get props :type))
+           (server (nnoo-current-server 'nnimap)))
+      (when (and stream (not (memq (process-status stream) '(open run))))
+	(setq stream nil))
+
+      (when (eq (process-type stream) 'network)
+        ;; Use TCP-keepalive so that connections that pass through a NAT
+        ;; router don't hang when left idle.
+        (set-network-process-option stream :keepalive t))
+
+      (setf (nnimap-process nnimap-object) stream)
+      (setf (nnimap-stream-type nnimap-object) stream-type)
+      (if (not stream)
+	  (prog1 'no-connect
+	    (nnheader-report 'nnimap "Unable to contact %s:%s via %s"
+			     nnimap-address (car ports) nnimap-stream))
+	(set-process-query-on-exit-flag stream nil)
+        (set-process-thread stream nil)
+	(if (not (string-match-p "[*.] \\(OK\\|PREAUTH\\)" greeting))
+	    (nnheader-report 'nnimap "%s" greeting)
+	  (setf (nnimap-greeting nnimap-object) greeting)
+	  (setf (nnimap-capabilities nnimap-object)
+		(mapcar #'upcase
+			(split-string capabilities)))
+	  (unless (string-match-p "[*.] PREAUTH" greeting)
+	    (if (not (setq credentials
+			   (if (eq nnimap-authenticator 'anonymous)
+			       (list "anonymous"
+				     (message-make-address))
+                             ;; Look for the credentials based on
+                             ;; the virtual server name and the address
+                             (nnimap-credentials
+			      (gnus-delete-duplicates
+			       (list server nnimap-address))
+                              ports
+                              nnimap-user))))
+		(setq nnimap-object nil)
+	      (let ((nnimap-inhibit-logging t))
+		(setq login-result
+		      (nnimap-login (car credentials) (cadr credentials))))
+	      (if (car login-result)
+		  (progn
+		    ;; Save the credentials if a save function exists
+		    ;; (such a function will only be passed if a new
+		    ;; token was created).
+		    (when (functionp (nth 2 credentials))
+		      (funcall (nth 2 credentials)))
+		    ;; See if CAPABILITY is set as part of login
+		    ;; response.
+		    (dolist (response (cddr (nnimap-command "CAPABILITY")))
+		      (when (string= "CAPABILITY" (upcase (car response)))
+			(setf (nnimap-capabilities nnimap-object)
+			      (mapcar #'upcase (cdr response)))))
+                    (when (and nnimap-use-namespaces
+                               (nnimap-capability "NAMESPACE"))
+                      (erase-buffer)
+                      (nnimap-wait-for-response (nnimap-send-command "NAMESPACE"))
+                      (let ((response (nnimap-last-response-string)))
+                        (when (string-match
+                               "^\\*\\W+NAMESPACE\\W+((\"\\([^\"\n]+\\)\"\\W+\"\\(.\\)\"))\\W+"
+                               response)
+                          (setq nnimap-namespace (match-string 1 response))))))
+                ;; If the login failed, then forget the credentials
+		;; that are now possibly cached.
+		(dolist (host (list (nnoo-current-server 'nnimap)
+				    nnimap-address))
+		  (dolist (port ports)
+                    (auth-source-forget+ :host host :port port)))
+		(delete-process (nnimap-process nnimap-object))
+		(setq nnimap-object nil))))
+	  (when nnimap-object
+	    (when (nnimap-capability "QRESYNC")
+	      (nnimap-command "ENABLE QRESYNC"))
+            (nnheader-message 7 "Opening connection to %s...done"
+			      nnimap-address)
+	    (nnimap-process nnimap-object)))))))
 
 (autoload 'rfc2104-hash "rfc2104")
 
@@ -656,7 +692,7 @@ nnimap-find-parameter
 (deffoo nnimap-close-server (&optional server defs)
   (when (nnoo-change-server 'nnimap server defs)
     (ignore-errors
-      (delete-process (get-buffer-process (nnimap-buffer))))
+      (delete-process (get-buffer-process (nnimap-process-buffer))))
     (nnoo-close-server 'nnimap server)
     t))
 
@@ -664,16 +700,13 @@ nnimap-request-close
   t)
 
 (deffoo nnimap-server-opened (&optional server)
-  (and (nnoo-current-server-p 'nnimap server)
-       nntp-server-buffer
-       (gnus-buffer-live-p nntp-server-buffer)
-       (nnimap-find-connection nntp-server-buffer)))
+  (nnoo-current-server-p 'nnimap server))
 
 (deffoo nnimap-status-message (&optional _server)
   nnimap-status-string)
 
 (deffoo nnimap-request-article (article &optional group server to-buffer)
-  (with-current-buffer nntp-server-buffer
+  (nnimap-with-context nntp-server-buffer
     (let ((result (nnimap-change-group group server))
 	  parts structure)
       (when (stringp article)
@@ -681,7 +714,7 @@ nnimap-request-article
       (when (and result
 		 article)
 	(erase-buffer)
-	(with-current-buffer (nnimap-buffer)
+	(with-current-buffer (nnimap-process-buffer)
 	  (erase-buffer)
 	  (when nnimap-fetch-partial-articles
 	    (nnimap-command "UID FETCH %d (BODYSTRUCTURE)" article)
@@ -705,7 +738,7 @@ nnimap-request-article
 
 (deffoo nnimap-request-head (article &optional group server to-buffer)
   (when (nnimap-change-group group server)
-    (with-current-buffer (nnimap-buffer)
+    (with-current-buffer (nnimap-process-buffer)
       (when (stringp article)
 	(setq article (nnimap-find-article-by-message-id group server article)))
       (if (null article)
@@ -721,11 +754,11 @@ nnimap-request-head
 	    (cons group article)))))))
 
 (deffoo nnimap-request-articles (articles &optional group server)
-  (with-current-buffer nntp-server-buffer
+  (nnimap-with-context nntp-server-buffer
     (let ((result (nnimap-change-group group server)))
       (when result
 	(erase-buffer)
-	(with-current-buffer (nnimap-buffer)
+	(with-current-buffer (nnimap-process-buffer)
 	  (erase-buffer)
 	  (when (nnimap-command
 		 (if (nnimap-ver4-p)
@@ -733,7 +766,7 @@ nnimap-request-articles
 		   "UID FETCH %s RFC822.PEEK")
 		 (nnimap-article-ranges (gnus-compress-sequence articles)))
 	    (let ((buffer (current-buffer)))
-	      (with-current-buffer nntp-server-buffer
+	      (nnimap-with-context nntp-server-buffer
 		(nnheader-insert-buffer-substring buffer)
 		(nnheader-ms-strip-cr)))
 	    t))))))
@@ -873,14 +906,13 @@ nnimap-request-group
   (let ((result (nnimap-change-group
 		 ;; Don't SELECT the group if we're going to select it
 		 ;; later, anyway.
-		 (if (and (not dont-check)
-			  (assoc group nnimap-current-infos))
-		     nil
+		 (when (or dont-check
+			   (not (assoc group nnimap-current-infos)))
 		   group)
 		 server))
 	(info (when info (list info)))
 	active)
-    (with-current-buffer nntp-server-buffer
+    (nnimap-with-context nntp-server-buffer
       (when result
 	(when (or (not dont-check)
 		  (not (setq active
@@ -902,7 +934,7 @@ nnimap-request-group
 (deffoo nnimap-request-group-scan (group &optional server info)
   (when (nnimap-change-group nil server)
     (let (marks high low)
-      (with-current-buffer (nnimap-buffer)
+      (with-current-buffer (nnimap-process-buffer)
 	(erase-buffer)
 	(let ((group-sequence
 	       (nnimap-send-command "SELECT %S" (nnimap-group-to-imap group)))
@@ -926,7 +958,7 @@ nnimap-request-group-scan
 			     (nth 3 (car marks)))
 			   0)
 		  low (or (nth 4 (car marks)) uidnext 1)))))
-      (with-current-buffer nntp-server-buffer
+      (nnimap-with-context nntp-server-buffer
 	(erase-buffer)
 	(insert
 	 (format
@@ -936,17 +968,17 @@ nnimap-request-group-scan
 
 (deffoo nnimap-request-create-group (group &optional server _args)
   (when (nnimap-change-group nil server)
-    (with-current-buffer (nnimap-buffer)
+    (with-current-buffer (nnimap-process-buffer)
       (car (nnimap-command "CREATE %S" (nnimap-group-to-imap group))))))
 
 (deffoo nnimap-request-delete-group (group &optional _force server)
   (when (nnimap-change-group nil server)
-    (with-current-buffer (nnimap-buffer)
+    (with-current-buffer (nnimap-process-buffer)
       (car (nnimap-command "DELETE %S" (nnimap-group-to-imap group))))))
 
 (deffoo nnimap-request-rename-group (group new-name &optional server)
   (when (nnimap-change-group nil server)
-    (with-current-buffer (nnimap-buffer)
+    (with-current-buffer (nnimap-process-buffer)
       (nnimap-unselect-group)
       (car (nnimap-command "RENAME %S %S"
 			   (nnimap-group-to-imap group) (nnimap-group-to-imap new-name))))))
@@ -960,13 +992,13 @@ nnimap-unselect-group
 
 (deffoo nnimap-request-expunge-group (group &optional server)
   (when (nnimap-change-group group server)
-    (with-current-buffer (nnimap-buffer)
+    (with-current-buffer (nnimap-process-buffer)
       (car (nnimap-command "EXPUNGE")))))
 
 (defun nnimap-get-flags (spec)
   (let ((articles nil)
 	elems end)
-    (with-current-buffer (nnimap-buffer)
+    (with-current-buffer (nnimap-process-buffer)
       (erase-buffer)
       (nnimap-wait-for-response (nnimap-send-command
 				 "UID FETCH %s FLAGS" spec))
@@ -984,7 +1016,7 @@ nnimap-get-flags
 (deffoo nnimap-close-group (_group &optional server)
   (when (eq nnimap-expunge 'on-exit)
     (nnoo-change-server 'nnimap server nil)
-    (with-current-buffer (nnimap-buffer)
+    (with-current-buffer (nnimap-process-buffer)
       (nnimap-command "EXPUNGE"))))
 
 (deffoo nnimap-request-move-article (article group server accept-form
@@ -1000,7 +1032,7 @@ nnimap-request-move-article
       ;; easy way.
       (let ((message-id (message-field-value "message-id")))
 	(if internal-move-group
-            (with-current-buffer (nnimap-buffer)
+            (with-current-buffer (nnimap-process-buffer)
               (let* ((can-move (and (nnimap-capability "MOVE")
 				    (equal (nnimap-quirk "MOVE") "MOVE")))
 		     (command (if can-move
@@ -1067,7 +1099,7 @@ nnimap-process-expiry-targets
 			      (gnus-server-to-method
 			       (format "nnimap:%s" server))))
       (and (nnimap-change-group group server)
-	   (with-current-buffer (nnimap-buffer)
+	   (with-current-buffer (nnimap-process-buffer)
 	     (nnheader-message 7 "Expiring articles from %s: %s" group articles)
              (let ((can-move (and (nnimap-capability "MOVE")
 				  (equal (nnimap-quirk "MOVE") "MOVE"))))
@@ -1112,7 +1144,7 @@ nnimap-process-expiry-targets
 (defun nnimap-find-expired-articles (group)
   (let ((cutoff (nnmail-expired-article-p group nil nil)))
     (when cutoff
-      (with-current-buffer (nnimap-buffer)
+      (with-current-buffer (nnimap-process-buffer)
 	(let ((result
 	       (nnimap-command
 		"UID SEARCH SENTBEFORE %s"
@@ -1126,7 +1158,7 @@ nnimap-find-article-by-message-id
 						&optional limit)
   "Search for message with MESSAGE-ID in GROUP from SERVER.
 If LIMIT, first try to limit the search to the N last articles."
-  (with-current-buffer (nnimap-buffer)
+  (with-current-buffer (nnimap-process-buffer)
     (erase-buffer)
     (let* ((change-group-result (nnimap-change-group group server nil t))
            (number-of-article
@@ -1156,7 +1188,7 @@ nnimap-find-article-by-message-id
 
 (defun nnimap-delete-article (articles)
   "Delete ARTICLES."
-  (with-current-buffer (nnimap-buffer)
+  (with-current-buffer (nnimap-process-buffer)
     (nnimap-command "UID STORE %s +FLAGS.SILENT (\\Deleted)"
 		    (nnimap-article-ranges articles))
     (cond
@@ -1208,13 +1240,13 @@ nnimap-request-update-group-status
 		    '((subscribe "SUBSCRIBE")
 		      (unsubscribe "UNSUBSCRIBE")))))
       (when command
-	(with-current-buffer (nnimap-buffer)
+	(with-current-buffer (nnimap-process-buffer)
 	  (nnimap-command "%s %S" (cadr command) (nnimap-group-to-imap group)))))))
 
 (deffoo nnimap-request-set-mark (group actions &optional server)
   (when (nnimap-change-group group server)
     (let (sequence)
-      (with-current-buffer (nnimap-buffer)
+      (with-current-buffer (nnimap-process-buffer)
 	(erase-buffer)
 	;; Just send all the STORE commands without waiting for
 	;; response.  If they're successful, they're successful.
@@ -1259,7 +1291,7 @@ nnimap-request-accept-article
 	  sequence message)
       (nnimap-add-cr)
       (setq message (buffer-substring-no-properties (point-min) (point-max)))
-      (with-current-buffer (nnimap-buffer)
+      (with-current-buffer (nnimap-process-buffer)
 	(when (setq message (or (nnimap-process-quirk "OK Gimap " 'append message)
 				message))
 	  ;; If we have this group open read-only, then unselect it
@@ -1392,14 +1424,14 @@ nnimap-get-responses
 
 (deffoo nnimap-request-list (&optional server)
   (when (nnimap-change-group nil server)
-    (with-current-buffer nntp-server-buffer
+    (nnimap-with-context nntp-server-buffer
       (erase-buffer)
       (let ((groups
-	     (with-current-buffer (nnimap-buffer)
+	     (with-current-buffer (nnimap-process-buffer)
 	       (nnimap-get-groups)))
 	    sequences responses)
 	(when groups
-	  (with-current-buffer (nnimap-buffer)
+	  (with-current-buffer (nnimap-process-buffer)
 	    (setf (nnimap-group nnimap-object) nil)
 	    (dolist (group groups)
 	      (setf (nnimap-examined nnimap-object) group)
@@ -1438,9 +1470,9 @@ nnimap-request-list
 
 (deffoo nnimap-request-newgroups (_date &optional server)
   (when (nnimap-change-group nil server)
-    (with-current-buffer nntp-server-buffer
+    (nnimap-with-context nntp-server-buffer
       (erase-buffer)
-      (dolist (group (with-current-buffer (nnimap-buffer)
+      (dolist (group (with-current-buffer (nnimap-process-buffer)
 		       (nnimap-get-groups)))
 	(unless (assoc group nnimap-current-infos)
 	  ;; Insert dummy numbers here -- they don't matter.
@@ -1448,9 +1480,8 @@ nnimap-request-newgroups
       t)))
 
 (deffoo nnimap-retrieve-group-data-early (server infos)
-  (when (and (nnimap-change-group nil server)
-	     infos)
-    (with-current-buffer (nnimap-buffer)
+  (when (nnimap-change-group nil server)
+    (with-current-buffer (nnimap-process-buffer)
       (erase-buffer)
       (setf (nnimap-group nnimap-object) nil)
       (setf (nnimap-initial-resync nnimap-object) 0)
@@ -1516,10 +1547,10 @@ nnimap-finish-retrieve-group-infos
   (when (and sequences
 	     (nnimap-change-group nil server t)
 	     ;; Check that the process is still alive.
-	     (get-buffer-process (nnimap-buffer))
-	     (memq (process-status (get-buffer-process (nnimap-buffer)))
+	     (get-buffer-process (nnimap-process-buffer))
+	     (memq (process-status (get-buffer-process (nnimap-process-buffer)))
 		   '(open run)))
-    (with-current-buffer (nnimap-buffer)
+    (with-current-buffer (nnimap-process-buffer)
       ;; Wait for the final data to trickle in.
       (when (nnimap-wait-for-response (if (eq (cadar sequences) 'qresync)
 					  (caar sequences)
@@ -1535,7 +1566,7 @@ nnimap-finish-retrieve-group-infos
 	(unless dont-insert
 	  ;; Finally, just return something resembling an active file in
 	  ;; the nntp buffer, so that the agent can save the info, too.
-	  (with-current-buffer nntp-server-buffer
+	  (nnimap-with-context nntp-server-buffer
 	    (erase-buffer)
 	    (dolist (info infos)
 	      (let* ((group (gnus-info-group info))
@@ -1870,8 +1901,20 @@ nnimap-parse-flags
 	  (setq articles nil))))
     groups))
 
-(defun nnimap-find-process-buffer (buffer)
-  (cadr (assoc buffer nnimap-connection-alist)))
+(defun nnimap-get-process-buffer (process-buffer-key)
+  (cl-flet ((get
+             (key)
+             (cl-find-if (lambda (b)
+                           (equal key (buffer-name b)))
+                         (gnus-buffers))))
+    (let ((extant (get process-buffer-key)))
+      (when (and extant (not (get-buffer-process extant)))
+        (gnus-kill-buffer extant)
+        (setq extant nil))
+      (or extant
+          (progn (nnimap-open-connection process-buffer-key)
+                 (get process-buffer-key))
+          (error "Cannot connect to %s" process-buffer-key)))))
 
 (deffoo nnimap-request-post (&optional _server)
   (setq nnimap-status-string "Read-only server")
@@ -1888,7 +1931,7 @@ nnimap-request-thread
       (nnselect-search-thread header)
     (when (nnimap-change-group group server)
       (let* ((cmd (nnimap-make-thread-query header))
-             (result (with-current-buffer (nnimap-buffer)
+             (result (with-current-buffer (nnimap-process-buffer)
                        (nnimap-command  "UID SEARCH %s" cmd))))
         (when result
           (gnus-fetch-headers
@@ -1915,7 +1958,7 @@ nnimap-change-group
      ((not group)
       t)
      (t
-      (with-current-buffer (nnimap-buffer)
+      (with-current-buffer (nnimap-process-buffer)
         (let ((result (nnimap-command "%s %S"
                                       (if read-only
                                           "EXAMINE"
@@ -1926,17 +1969,18 @@ nnimap-change-group
                   (nnimap-select-result nnimap-object) result)
             result)))))))
 
-(defun nnimap-find-connection (buffer)
-  "Find the connection delivering to BUFFER."
-  (let ((entry (assoc buffer nnimap-connection-alist)))
-    (when entry
-      (if (and (buffer-live-p (cadr entry))
-	       (get-buffer-process (cadr entry))
-	       (memq (process-status (get-buffer-process (cadr entry)))
-		     '(open run)))
-	  (get-buffer-process (cadr entry))
-	(setq nnimap-connection-alist (delq entry nnimap-connection-alist))
-	nil))))
+(defun nnimap-find-connection (_buffer)
+  "Find the connection delivering to BUFFER.
+Confusingly, BUFFER will always be `nntp-server-buffer', i.e.,\" *nntpd*\",
+so `nnimap-connection-alist' will usually be of length 1, and look like,
+\((#<buffer  *nntpd*> #<buffer  *nnimap localhost 143  *nntpd**-XXXXXX>))
+
+Multiplexing of different imap servers is made possible because
+`nnoo-change-server' deftly swaps out this associative pair with the
+current imap source (only the XXXXXX string changes).
+
+This is all changing."
+  (cl-assert nil))
 
 ;; Leave room for `open-network-stream' to issue a couple of IMAP
 ;; commands before nnimap starts.
@@ -2012,8 +2056,8 @@ nnimap-wait-for-line
 	 (match-string 1))))
 
 (defun nnimap-wait-for-response (sequence &optional messagep)
-  (let ((process (get-buffer-process (current-buffer)))
-	openp)
+  (let (openp
+        (process (get-buffer-process (current-buffer))))
     (condition-case nil
         (progn
 	  (goto-char (point-max))
@@ -2140,7 +2184,7 @@ nnimap-fetch-inbox
    t))
 
 (defun nnimap-split-incoming-mail ()
-  (with-current-buffer (nnimap-buffer)
+  (with-current-buffer (nnimap-process-buffer)
     (let ((nnimap-incoming-split-list nil)
 	  (nnmail-split-methods
 	   (cond
diff --git a/lisp/gnus/nnmail.el b/lisp/gnus/nnmail.el
index bcf01cfa9e..d8c9d5005c 100644
--- a/lisp/gnus/nnmail.el
+++ b/lisp/gnus/nnmail.el
@@ -29,7 +29,6 @@
 (require 'gnus)				; for macro gnus-kill-buffer, at least
 (require 'nnheader)
 (require 'message)
-(require 'gnus-util)
 (require 'mail-source)
 (require 'mm-util)
 (require 'gnus-int)
@@ -1624,7 +1623,7 @@ nnmail-cache-insert
 	  (insert id "\n"))))))
 
 (defun nnmail-cache-primary-mail-backend ()
-  (let ((be-list (cons gnus-select-method gnus-secondary-select-methods))
+  (let ((be-list gnus-select-methods)
 	(be nil)
 	(res nil)
         (get-new-mail nil))
diff --git a/lisp/gnus/nnmaildir.el b/lisp/gnus/nnmaildir.el
index 4867455393..a2bc109673 100644
--- a/lisp/gnus/nnmaildir.el
+++ b/lisp/gnus/nnmaildir.el
@@ -50,7 +50,6 @@
 
 (require 'nnheader)
 (require 'gnus)
-(require 'gnus-util)
 (require 'gnus-range)
 (require 'gnus-start)
 (require 'gnus-int)
diff --git a/lisp/gnus/nnrss.el b/lisp/gnus/nnrss.el
index a40fa88631..4a796b1bc4 100644
--- a/lisp/gnus/nnrss.el
+++ b/lisp/gnus/nnrss.el
@@ -31,7 +31,6 @@
 (require 'nnmail)
 (require 'message)
 (require 'mm-util)
-(require 'gnus-util)
 (require 'time-date)
 (require 'rfc2231)
 (require 'mm-url)
diff --git a/lisp/gnus/nntp.el b/lisp/gnus/nntp.el
index 1fd2ed06eb..1050779cc4 100644
--- a/lisp/gnus/nntp.el
+++ b/lisp/gnus/nntp.el
@@ -27,8 +27,6 @@
 
 (require 'nnheader)
 (require 'nnoo)
-(require 'gnus-util)
-(require 'gnus)
 (require 'gnus-group) ;; gnus-group-name-charset
 
 (nnoo-declare nntp)
@@ -252,7 +250,6 @@ nntp-server-list-active-group
 
 ;;; Internal variables.
 
-(defvoo nntp-retrieval-in-progress nil)
 (defcustom nntp-record-commands nil
   "If non-nil, nntp will record all commands in the \"*nntp-log*\" buffer."
   :type 'boolean)
@@ -399,9 +396,8 @@ nntp-wait-for
 
 (defun nntp-kill-buffer (buffer)
   (when (buffer-live-p buffer)
-    (let ((process (get-buffer-process buffer)))
-      (when process
-	(delete-process process)))
+    (when-let ((process (get-buffer-process buffer)))
+      (delete-process process))
     (kill-buffer buffer)
     (nnheader-init-server-buffer)))
 
@@ -410,7 +406,7 @@ nntp-erase-buffer
   (with-current-buffer buffer
     (erase-buffer)))
 
-(defsubst nntp-find-connection (buffer)
+(defun nntp-find-connection (buffer)
   "Find the connection delivering to BUFFER."
   (let ((alist nntp-connection-alist)
 	(buffer (if (stringp buffer) (get-buffer buffer) buffer))
@@ -432,9 +428,8 @@ nntp-find-connection-entry
 
 (defun nntp-find-connection-buffer (buffer)
   "Return the process connection buffer tied to BUFFER."
-  (let ((process (nntp-find-connection buffer)))
-    (when process
-      (process-buffer process))))
+  (when-let ((process (nntp-find-connection buffer)))
+    (process-buffer process)))
 
 (defun nntp-retrieve-data (command address _port buffer
 				      &optional wait-for callback decode)
@@ -528,8 +523,8 @@ nntp-send-command-nodelete
 
 (defun nntp-send-command-and-decode (wait-for &rest strings)
   "Send STRINGS to server and wait until WAIT-FOR returns."
-  (when (not (or nnheader-callback-function
-                 nntp-inhibit-output))
+  (when (and (not nnheader-callback-function)
+             (not nntp-inhibit-output))
     (nntp-erase-buffer nntp-server-buffer))
   (let* ((command (mapconcat #'identity strings " "))
 	 (process (nntp-find-connection nntp-server-buffer))
@@ -734,32 +729,19 @@ nntp-retrieve-headers
 (deffoo nntp-retrieve-group-data-early (server infos)
   "Retrieve group info on INFOS."
   (nntp-with-open-group nil server
-    (let ((buffer (nntp-find-connection-buffer nntp-server-buffer)))
-      (unless infos
-	(with-current-buffer buffer
-	  (setq nntp-retrieval-in-progress nil)))
-      (when (and buffer
-		 infos
-		 (with-current-buffer buffer
-		   (not nntp-retrieval-in-progress)))
-	;; The first time this is run, this variable is `try'.  So we
-	;; try.
-	(when (eq nntp-server-list-active-group 'try)
-	  (nntp-try-list-active
-	   (gnus-group-real-name (gnus-info-group (car infos)))))
-	(with-current-buffer buffer
-	  (erase-buffer)
-	  ;; Mark this buffer as "in use" in case we try to issue two
-	  ;; retrievals from the same server.  This shouldn't happen,
-	  ;; so this is mostly a sanity check.
-	  (setq nntp-retrieval-in-progress t)
-	  (let ((nntp-inhibit-erase t)
-		(command (if nntp-server-list-active-group
-			     "LIST ACTIVE" "GROUP")))
-	    (dolist (info infos)
-	      (nntp-send-command
-	       nil command (gnus-group-real-name (gnus-info-group info)))))
-	  (length infos))))))
+    (when-let ((buffer (nntp-find-connection-buffer nntp-server-buffer)))
+      (when (eq nntp-server-list-active-group 'try) ;; `try' is initial value
+	(nntp-try-list-active
+	 (gnus-group-real-name (gnus-info-group (car infos)))))
+      (with-current-buffer buffer
+	(erase-buffer)
+	(let ((nntp-inhibit-erase t)
+	      (command (if nntp-server-list-active-group
+			   "LIST ACTIVE" "GROUP")))
+	  (dolist (info infos)
+	    (nntp-send-command
+	     nil command (gnus-group-real-name (gnus-info-group info)))))
+	(length infos)))))
 
 (deffoo nntp-finish-retrieve-group-infos (server infos count)
   (nntp-with-open-group nil server
@@ -769,8 +751,6 @@ nntp-finish-retrieve-group-infos
 		   (car infos)))
 	  (received 0)
 	  (last-point 1))
-      (with-current-buffer buf
-	(setq nntp-retrieval-in-progress nil))
       (when (and buf
 		 count)
 	(with-current-buffer buf
@@ -815,14 +795,7 @@ nntp-retrieve-groups
   "Retrieve group info on GROUPS."
   (nntp-with-open-group
    nil server
-   (when (and (nntp-find-connection-buffer nntp-server-buffer)
-	      (with-current-buffer
-		  (nntp-find-connection-buffer nntp-server-buffer)
-		(if (not nntp-retrieval-in-progress)
-		    t
-		  (message "Warning: Refusing to do retrieval from %s because a retrieval is already happening"
-			   server)
-		  nil)))
+   (when (nntp-find-connection-buffer nntp-server-buffer)
      (catch 'done
        (save-excursion
          ;; Erase nntp-server-buffer before nntp-inhibit-erase.
@@ -1235,8 +1208,7 @@ nntp-make-process-buffer
 		nntp-process-callback nil
 		nntp-process-to-buffer nil
 		nntp-process-start-point nil
-		nntp-process-decode nil
-		nntp-retrieval-in-progress nil)
+		nntp-process-decode nil)
     (current-buffer)))
 
 (defun nntp-open-connection (buffer)
@@ -1311,6 +1283,19 @@ nntp-open-connection
 	  (prog1
 	      (caar (push (list process buffer nil) nntp-connection-alist))
 	    (push process nntp-connection-list)
+            (with-current-buffer buffer
+              (add-hook 'kill-buffer-hook
+                        (apply-partially
+                         (lambda (buffer)
+                           (when-let ((process
+                                       (car (nntp-find-connection-entry buffer))))
+                             (setq nntp-connection-list
+                                   (delq process nntp-connection-list))
+                             (setq nntp-connection-alist
+                                   (assq-delete-all process nntp-connection-alist))
+                             (ignore-errors (delete-process process))))
+                         buffer)
+                        nil t))
 	    (with-current-buffer pbuffer
 	      (nntp-read-server-type)
 	      (erase-buffer)
diff --git a/lisp/gnus/nnvirtual.el b/lisp/gnus/nnvirtual.el
index 03a0ff296f..7ee21c633a 100644
--- a/lisp/gnus/nnvirtual.el
+++ b/lisp/gnus/nnvirtual.el
@@ -32,9 +32,7 @@
 
 (require 'nntp)
 (require 'nnheader)
-(require 'gnus)
 (require 'nnoo)
-(require 'gnus-util)
 (require 'gnus-start)
 (require 'gnus-sum)
 (require 'gnus-msg)
diff --git a/lisp/gnus/nnweb.el b/lisp/gnus/nnweb.el
index f08dc47e31..b8cfacb5d5 100644
--- a/lisp/gnus/nnweb.el
+++ b/lisp/gnus/nnweb.el
@@ -24,11 +24,8 @@
 
 ;;; Code:
 
-(eval-when-compile (require 'cl-lib))
-
 (require 'nnoo)
 (require 'message)
-(require 'gnus-util)
 (require 'gnus)
 (require 'nnmail)
 (require 'mm-util)
diff --git a/lisp/obsolete/nnir.el b/lisp/obsolete/nnir.el
index 40a8ec57b9..51dd14de95 100644
--- a/lisp/obsolete/nnir.el
+++ b/lisp/obsolete/nnir.el
@@ -37,7 +37,7 @@
 ;; The Lisp setup may involve setting a few variables and setting up the
 ;; search engine.  You can define the variables in the server definition
 ;; like this :
-;;   (setq gnus-secondary-select-methods '(
+;;   (setq gnus-select-methods '(
 ;;       (nnimap "" (nnimap-address "localhost")
 ;;                  (nnir-search-engine namazu)
 ;;       )))
@@ -518,7 +518,7 @@ nnir-compose-result
 
 (autoload 'gnus-server-get-active "gnus-int")
 (autoload 'nnimap-change-group "nnimap")
-(declare-function nnimap-buffer "nnimap" ())
+(declare-function nnimap-process-buffer "nnimap" ())
 (declare-function nnimap-command "nnimap" (&rest args))
 
 ;; imap interface
@@ -547,7 +547,7 @@ nnir-run-imap
 		(condition-case ()
 		    (when (nnimap-change-group
 			   (gnus-group-short-name group) server)
-		      (with-current-buffer (nnimap-buffer)
+		      (with-current-buffer (nnimap-process-buffer)
 			(message "Searching %s..." group)
 			(let ((arts 0)
 			      (result (nnimap-command "UID SEARCH %s"
diff --git a/lisp/org/ol-gnus.el b/lisp/org/ol-gnus.el
index 2d51447e0c..d913e5fc02 100644
--- a/lisp/org/ol-gnus.el
+++ b/lisp/org/ol-gnus.el
@@ -32,7 +32,6 @@
 ;;; Code:
 
 (require 'gnus-sum)
-(require 'gnus-util)
 (require 'nnheader)
 (or (require 'nnselect nil t)           ; Emacs >= 28
     (require 'nnir nil t))              ; Emacs < 28
diff --git a/test/lisp/gnus/gnus-test-select-methods.el b/test/lisp/gnus/gnus-test-select-methods.el
new file mode 100644
index 0000000000..6fdde070e5
--- /dev/null
+++ b/test/lisp/gnus/gnus-test-select-methods.el
@@ -0,0 +1,103 @@
+;;; gnus-test-select-methods.el    -*- lexical-binding:t -*-
+
+;; Copyright (C) 2019 Free Software Foundation, Inc.
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Code:
+
+(require 'ert)
+(require 'gnus)
+(require 'gnus-int)
+(require 'gnus-start)
+
+(eval-when-compile
+  (put 'gnus-secondary-select-methods 'byte-obsolete-variable nil)
+  (put 'gnus-select-method 'byte-obsolete-variable nil)
+  (put 'gnus-nntp-server 'byte-obsolete-variable nil))
+
+(ert-deftest gnus-test-select-methods-basic ()
+  "Customizing `gnus-select-method' and `gnus-secondary-select-methods'
+also modifies `gnus-select-methods'."
+  (let (gnus-select-method
+        gnus-secondary-select-methods
+        gnus-select-methods
+        (test-methods '((nnnil) (nntp "flab.flab.edu"))))
+    (custom-set-variables `(gnus-select-method (quote ,(car test-methods)))
+                          `(gnus-secondary-select-methods (quote ,(cdr test-methods))))
+    (should (cl-every #'identity
+                      (cl-mapcar #'gnus-methods-equal-p gnus-select-methods test-methods)))
+    (should (gnus-method-equal gnus-select-method (car gnus-select-methods)))
+    (should (cl-every #'identity
+                      (cl-mapcar #'gnus-methods-equal-p gnus-secondary-select-methods
+                                 (cdr gnus-select-methods))))))
+
+(ert-deftest gnus-test-select-methods-out-of-band ()
+  "Hamfistedly setting, not customizing, `gnus-select-method' and
+`gnus-secondary-select-methods' also modifies `gnus-select-methods'."
+  (let (gnus-select-method
+        gnus-secondary-select-methods
+        gnus-select-methods
+        (test-methods '((nnnil) (nntp "flab.flab.edu"))))
+    (setq gnus-select-method (car test-methods)
+          gnus-secondary-select-methods (cdr test-methods))
+    (should (cl-every #'identity
+                      (cl-mapcar #'gnus-methods-equal-p gnus-select-methods test-methods)))
+    (should (gnus-method-equal gnus-select-method (car gnus-select-methods)))
+    (should (cl-every #'identity
+                      (cl-mapcar #'gnus-methods-equal-p gnus-secondary-select-methods
+                                 (cdr gnus-select-methods))))))
+
+(ert-deftest gnus-test-select-methods-override ()
+  "Customizing `gnus-select-methods' overrides earlier customizations
+of `gnus-select-method' and `gnus-secondary-select-methods'."
+  (let (gnus-select-method
+        gnus-secondary-select-methods
+        gnus-select-methods
+        (test-methods '((nnnil) (nntp "flab.flab.edu")))
+        (override-methods '((nntp "override") (nnnil))))
+    (custom-set-variables `(gnus-select-method (quote ,(car test-methods)))
+                          `(gnus-secondary-select-methods (quote ,(cdr test-methods)))
+                          `(gnus-select-methods (quote ,override-methods)))
+    (should (cl-every #'identity
+                      (cl-mapcar #'gnus-methods-equal-p gnus-select-methods override-methods)))
+    (should (gnus-method-equal gnus-select-method (car gnus-select-methods)))
+    (should (cl-every #'identity
+                      (cl-mapcar #'gnus-methods-equal-p gnus-secondary-select-methods
+                                 (cdr gnus-select-methods))))))
+
+(ert-deftest gnus-test-gnus-start-news-server ()
+  "Test an archaic method of initiating gnus."
+  (let (gnus-current-select-method
+        (gnus-nntp-server "::"))
+    (cl-letf (((symbol-function 'gnus-y-or-n-p) #'ignore))
+      (gnus-start-news-server)
+      (should (gnus-method-equal gnus-select-method `(nnspool ,(system-name)))))))
+
+(ert-deftest gnus-test-gnus-read-active-file ()
+  "Ensure unification does right by `gnus-read-active-file'."
+  (let (gnus-select-method
+        gnus-secondary-select-methods
+        gnus-select-methods
+        (test-methods '((nnnil) (nntp "flab.flab.edu"))))
+    (custom-set-variables `(gnus-select-methods (quote ,test-methods)))
+    (should (equal
+             (cl-remove-if (lambda (method)
+                             (gnus-method-equal method gnus-select-method))
+                           gnus-select-methods)
+             gnus-secondary-select-methods))))
+
+;;; gnus-test-select-methods.el ends here
diff --git a/test/lisp/gnus/gnus-tests.el b/test/lisp/gnus/gnus-tests.el
index 6602e67a34..c65c2ce880 100644
--- a/test/lisp/gnus/gnus-tests.el
+++ b/test/lisp/gnus/gnus-tests.el
@@ -25,9 +25,95 @@
 ;; tests that are not standalone.
 
 ;;; Code:
-;; registry.el is required by gnus-registry.el but this way we're explicit.
-(require 'registry)
-(require 'gnus-registry)
+;;
+
+(require 'cl-macs)
+(require 'message)
+(require 'gnus)
+(require 'gnus-start)
+(require 'nsm)
+
+(defconst gnus-tests-load-file-name (or load-file-name
+                                        (buffer-file-name)))
+
+(defmacro gnus-tests-let-customs (bindings &rest forms)
+  (declare (indent defun))
+  `(let (,@(mapcar #'car bindings))
+     (ignore ,@(mapcar #'car bindings))
+     (funcall #'custom-set-variables
+              ,@(mapcar (apply-partially #'list 'quote) bindings))
+     ,@forms))
+
+(cl-defmacro gnus-tests-doit (&rest
+                              body
+                              &key
+                              (select-methods '(default-value 'gnus-select-methods))
+                              (customs)
+                              &allow-other-keys
+                              &aux
+                              (body
+                               (cl-loop until (not (keywordp (car body)))
+                                        do (setq body (nthcdr 2 body))
+                                        finally return body)))
+  (declare (indent defun))
+  `(let* ((parent-dir (file-name-directory gnus-tests-load-file-name))
+          (default-directory (file-name-as-directory (concat parent-dir "gnus-tests")))
+	  (user-emacs-directory default-directory))
+     (unless (file-exists-p default-directory)
+       (make-directory default-directory))
+     (gnus-tests-let-customs
+       ((gnus-verbose 8)
+        (gnus-save-dot-newsrc nil)
+        (gnus-home-directory default-directory)
+        (gnus-use-dribble-file nil)
+        (network-security-level (quote low))
+        (gnus-interactive-exit (quote quiet))
+        (gnus-select-methods ,select-methods)
+        (message-directory (concat default-directory "Mail"))
+        (mail-source-directory message-directory)
+        (mail-source-crash-box (concat default-directory ".whatev"))
+        (gnus-newsrc-file (nnheader-concat gnus-home-directory ".newsrc.eld"))
+        (gnus-init-file (nnheader-concat gnus-home-directory ".gnus"))
+        (gnus-directory (nnheader-concat gnus-home-directory "News/"))
+        ,@customs)
+       (unwind-protect
+           (progn ,@body)
+         (cl-macrolet ((safe-delete
+                        (x)
+                        `(if (cl-search "gnus-tests/" ,x)
+                             (delete-directory ,x t)
+                           (error "Attempted delete of %s!" ,x))))
+           (safe-delete default-directory))))))
+
+(ert-deftest gnus-test-clean-room ()
+  (gnus-tests-doit
+    (should (equal gnus-select-methods (default-value 'gnus-select-methods)))
+    (should-not gnus-save-dot-newsrc))
+  (should gnus-save-dot-newsrc))
+
+(ert-deftest gnus-test-select-methods ()
+  (gnus-tests-doit :select-methods (quote ((nnfolder "")))
+    (should (equal gnus-select-methods (quote ((nnfolder "")))))
+    (should (equal gnus-select-method (quote (nnfolder ""))))
+    (should-not gnus-secondary-select-methods)))
+
+(ert-deftest gnus-test-be-nicer-to-noobs ()
+  "Between the time Linux entered the home and the time I wrote this test,
+the innocent user trying `M-x gnus` would be rebuffed with hostility."
+  (gnus-tests-doit
+    (with-current-buffer "*Messages*"
+      (let ((inhibit-read-only t))
+        (erase-buffer)))
+    (let ((inhibit-message t))
+      (call-interactively #'gnus))
+    (with-current-buffer "*Messages*"
+      (save-excursion
+        (goto-char (point-min))
+        (should-error (re-search-forward "failed"))))))
+
+(ert-deftest gnus-test-basic-op ()
+  (gnus-tests-doit :select-methods (quote ((nnfolder "")))
+    (call-interactively #'gnus)))
 
 (provide 'gnus-tests)
 ;;; gnus-tests.el ends here
diff --git a/test/src/process-tests.el b/test/src/process-tests.el
index b64c82c87d..708473bf8a 100644
--- a/test/src/process-tests.el
+++ b/test/src/process-tests.el
@@ -111,6 +111,15 @@ process-test-stderr-buffer
 	      (goto-char (point-min))
 	      (looking-at "hello stderr!"))))))
 
+(ert-deftest process-test-stopped-pipe ()
+  (skip-unless (executable-find "cat"))
+  (with-temp-buffer
+    (let ((proc (make-pipe-process :name "pipe" :buffer (current-buffer)
+                                   :command '("cat") :stop t)))
+      (unwind-protect
+          (should (list-processes--refresh))
+        (delete-process proc)))))
+
 (ert-deftest process-test-stderr-filter ()
   (skip-unless (executable-find "bash"))
   (with-timeout (60 (ert-fail "Test timed out"))
diff --git a/test/src/thread-tests.el b/test/src/thread-tests.el
index fc7bc7441b..2b0fcb5383 100644
--- a/test/src/thread-tests.el
+++ b/test/src/thread-tests.el
@@ -20,6 +20,8 @@
 ;;; Code:
 
 (require 'thread)
+(require 'eieio)
+(require 'ring)
 
 ;; Declare the functions in case Emacs has been configured --without-threads.
 (declare-function all-threads "thread.c" ())
@@ -42,6 +44,26 @@
 (declare-function thread-yield "thread.c" ())
 (defvar main-thread)
 
+(defclass threads-test-channel ()
+  ((condition :initarg :condition :type condition-variable)
+   (msg-queue :initarg :msg-queue :type ring)))
+
+(cl-defgeneric threads-test-channel-send ((channel threads-test-channel) message)
+  (with-slots (condition msg-queue) channel
+    (with-mutex (condition-mutex condition)
+      (while (<= (ring-size msg-queue) (ring-length msg-queue))
+        (condition-wait condition))
+      (ring-insert msg-queue message)
+      (condition-notify condition t))))
+
+(cl-defgeneric threads-test-channel-recv ((channel threads-test-channel))
+  (with-slots (condition msg-queue) channel
+    (with-mutex (condition-mutex condition)
+      (while (ring-empty-p msg-queue)
+        (condition-wait condition))
+      (prog1 (ring-remove msg-queue)
+        (condition-notify condition t)))))
+
 (ert-deftest threads-is-one ()
   "Test for existence of a thread."
   (skip-unless (featurep 'threads))
@@ -318,7 +340,7 @@ threads-signal-early
          (make-thread (lambda ()
                         (while t (thread-yield))))))
     (thread-signal thread 'error nil)
-    (sit-for 1)
+    (funcall (if noninteractive #'sit-for #'sleep-for) 1)
     (should-not (thread-live-p thread))
     (should (equal (thread-last-error) '(error)))))
 
@@ -389,7 +411,99 @@ threads-condvar-wait
     (should (equal (thread-last-error) '(error "Die, die, die!")))))
 
 (ert-deftest threads-test-bug33073 ()
+  (skip-unless (featurep 'threads))
   (let ((th (make-thread 'ignore)))
     (should-not (equal th main-thread))))
 
-;;; threads.el ends here
+(ert-deftest threads-test-bug36609-signal ()
+  "Would only fail under TEST_INTERACTIVE=yes, and not every time.
+The failure manifests only by being unable to exit the interactive emacs."
+  (skip-unless (featurep 'threads))
+  (let* ((cv (make-condition-variable (make-mutex) "CV"))
+       condition
+       (notify (lambda ()
+                 (sleep-for 1) ;; let wait() start spinning first
+                 (with-mutex (condition-mutex cv)
+                   (setq condition t)
+                   (condition-notify cv))))
+       (wait (lambda () (with-mutex (condition-mutex cv)
+                          (while (not condition)
+                            (condition-wait cv)))))
+       (herring (make-thread (apply-partially #'sleep-for 1000) "unrelated")))
+    ;; herring is a non-main thread that, if the bug is still present,
+    ;; could assume the glib context lock when the main thread executes wait()
+    (make-thread notify "notify")
+    (funcall wait)
+    (thread-signal herring 'quit nil)))
+
+(ert-deftest threads-test-glib-lock ()
+  "Would only fail under TEST_INTERACTIVE=yes, and not every time.
+The failure manifests only by being unable to exit the interactive emacs."
+  (skip-unless (featurep 'threads))
+  (cl-macrolet ((run-thread
+                 (name what)
+                 `(make-thread
+                   (lambda ()
+                     (sleep-for (1+ (random 3)))
+                     (funcall ,what))
+                   ,name)))
+    (let* ((n 3)
+           (capacity 1)
+           (channel (make-instance
+                     'threads-test-channel
+                     :condition (make-condition-variable (make-mutex) "channel")
+                     :msg-queue (make-ring capacity))))
+      (dotimes (i n)
+        (let ((send-name (format "send-%d" (1+ i)))
+	      (recv-name (format "recv-%d" (- n i))))
+          (run-thread send-name
+		      (lambda () (threads-test-channel-send channel 42)))
+          (run-thread recv-name
+		      (lambda () (threads-test-channel-recv channel))))))))
+
+(ert-deftest threads-test-promiscuous-process ()
+  "Can't we `accept-process-output' of a process started by another thread?
+For whatever reason, in 2012, tromey inserted an assertion forbidding this.
+We test flouting that edict here."
+  (skip-unless (featurep 'threads))
+  (thread-last-error t)
+  (let* ((thread-tests-main (get-buffer-create "thread-tests-main" t))
+         (buffers (list thread-tests-main))
+         (start-proc (lambda (n b)
+                       (apply #'start-process n b "cat" (split-string "/dev/urandom"))))
+         (n 3))
+    (funcall start-proc "threads-tests-main" (car buffers))
+    (dotimes (i (1- n))
+      (push (get-buffer-create (format "thread-tests-%d" i) t) buffers)
+      (make-thread (apply-partially start-proc
+                                    (format "thread-tests-%d" i)
+                                    (car buffers))))
+    (should (cl-loop repeat 10
+                     when (cl-every #'processp (mapcar #'get-buffer-process buffers))
+                     return t
+                     do (accept-process-output nil 0.1)
+                     finally return nil))
+    (let ((procs (mapcar #'get-buffer-process buffers)))
+      (mapc (lambda (proc) (set-process-thread proc nil)) procs)
+      (dotimes (i (1- n))
+        (make-thread
+         (lambda ()
+           (cl-loop repeat 5
+                    do (accept-process-output
+                        (nth (random (length procs)) procs)
+                        0.2
+                        nil
+                        t)))
+         (format "thread-tests-%d" i)))
+      (should (cl-loop repeat 20
+                       unless (cl-some
+                               (lambda (thr)
+                                 (cl-search "thread-tests-" (thread-name thr)))
+                               (all-threads))
+                       return t
+                       do (accept-process-output
+                           (nth (random (length procs)) procs) 1.0)
+                       finally return nil)))
+    (mapc (lambda (b) (kill-buffer b)) buffers))
+  (should-not (thread-last-error t)))
+;;; thread-tests.el ends here
-- 
2.26.2