>From 01ebb45b5e6bc22a5db55343bb6084d9a1800f2e Mon Sep 17 00:00:00 2001 From: Phil Sainty Date: Sun, 3 Sep 2017 14:30:18 +1200 Subject: [PATCH] Avoid creating inconsistent buffer states in term-char-mode (bug#24837) * lisp/term.el (term-mode, term-char-mode, term-line-mode) (term-emulate-terminal): Make buffer read-only in `term-char-mode', except for the process filter's output. Use `read-only-mode-hook' to track and restore the user-set state of `buffer-read-only' for `term-line-mode'. term-line-mode-buffer-read-only: New variable. (term-line-mode-buffer-read-only-update): New function. (term-char-mode, term-line-mode): Use `term-set-goto-process-mark' in pre-command-hook, and `term-goto-process-mark-maybe' in post-command-hook to counter-act unexpected changes to point. term-goto-process-mark: New buffer-local variable. (term-set-goto-process-mark): New function. (term-goto-process-mark-maybe): New function. (term-process-mark): New function. --- lisp/term.el | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) diff --git a/lisp/term.el b/lisp/term.el index c748c45..32dcb5a 100644 --- a/lisp/term.el +++ b/lisp/term.el @@ -427,6 +427,8 @@ term-old-mode-map (defvar term-old-mode-line-format) ; Saves old mode-line-format while paging. (defvar term-pager-old-local-map nil "Saves old keymap while paging.") (defvar term-pager-old-filter) ; Saved process-filter while paging. +(defvar-local term-line-mode-buffer-read-only nil + "The `buffer-read-only' state to set in `term-line-mode'.") (defcustom explicit-shell-file-name nil "If non-nil, is file name to use for explicitly requested inferior shell." @@ -1105,6 +1107,8 @@ term-mode (term-reset-size (cdr size) (car size))) size)) + (add-hook 'read-only-mode-hook #'term-line-mode-buffer-read-only-update nil t) + (easy-menu-add term-terminal-menu) (easy-menu-add term-signals-menu) (or term-input-ring @@ -1246,6 +1250,12 @@ term-char-mode (easy-menu-add term-terminal-menu) (easy-menu-add term-signals-menu) + ;; Don't allow changes to the buffer or to point which are not + ;; caused by the process filter. + (setq buffer-read-only 1) + (add-hook 'pre-command-hook #'term-set-goto-process-mark nil t) + (add-hook 'post-command-hook #'term-goto-process-mark-maybe nil t) + ;; Send existing partial line to inferior (without newline). (let ((pmark (process-mark (get-buffer-process (current-buffer)))) (save-input-sender term-input-sender)) @@ -1265,9 +1275,17 @@ term-line-mode you type \\[term-send-input] which sends the current line to the inferior." (interactive) (when (term-in-char-mode) + (setq buffer-read-only term-line-mode-buffer-read-only) + (remove-hook 'pre-command-hook #'term-set-goto-process-mark t) + (remove-hook 'post-command-hook #'term-goto-process-mark-maybe t) (use-local-map term-old-mode-map) (term-update-mode-line))) +(defun term-line-mode-buffer-read-only-update () + "Update the user-set state of `buffer-read-only' in `term-line-mode'." + (when (term-in-line-mode) + (setq term-line-mode-buffer-read-only buffer-read-only))) + (defun term-update-mode-line () (let ((term-mode (if (term-in-char-mode) @@ -2711,6 +2729,7 @@ term-emulate-terminal count-bytes ; number of bytes decoded-substring save-point save-marker old-point temp win + (inhibit-read-only t) (buffer-undo-list t) (selected (selected-window)) last-win @@ -3109,6 +3128,39 @@ term-emulate-terminal (when (get-buffer-window (current-buffer)) (redisplay)))) +(defvar-local term-goto-process-mark t + "Whether to reset point to the current process mark after each command. + +Set in `pre-command-hook' by `term-set-goto-process-mark'.") + +(defun term-set-goto-process-mark () + "Sets `term-goto-process-mark'. Called during `pre-command-hook'. + +Ensures that when point is equal to the process mark at the +pre-command stage, it will be returned to the process mark at the +post-command stage. See also `term-goto-process-mark-maybe'." + (setq term-goto-process-mark + (eq (point) (marker-position (term-process-mark))))) + +(defun term-goto-process-mark-maybe () + "Move point to the term buffer's process mark upon keyboard input. + +Used as a buffer-local `post-command-hook' function in +`term-char-mode' to prevent commands from putting the buffer into +an inconsistent state by unexpectedly moving point. + +Only acts when the pre-command position of point was equal to the +current process mark. + +Mouse events are ignored so that mouse selection is unimpeded." + (unless (mouse-event-p last-command-event) + (when term-goto-process-mark + (goto-char (term-process-mark))))) + +(defun term-process-mark () + "The current process-mark for the term buffer process." + (process-mark (get-buffer-process (current-buffer)))) + (defun term-handle-deferred-scroll () (let ((count (- (term-current-row) term-height))) (when (>= count 0) -- 2.8.3