[VM] Why is vm closing imap session on each vm-get-new-mail?

[Mark Diekhans]

Does anyone know why vm-imap closes sessions after retrieving
mail? The "The IMAP session protocol" section in vm-imap.e
describes this but doesn't indicate the motivation. There is
also some discusion in the "The IMAP sessions work as follows"
indicates this is because another connection may have deleted
messages.

For some reason, gmail IMAP login has gotten very slow recently;
to the point that I was thinking of running a caching imap proxy
on my laptop :-(

I have changed calls to vm-establish-new-folder-imap-session to
vm-re-establish-folder-imap-session and all seems to work fine
and it's much faster.

However, when I delete a message from the gmail interface and
then do a (vm-imap-synchronize nil) with the connection is open.
I get the below error.

Any insight on the design? 

Thanks
Mark




Debugger entered--Lisp error: (void-variable \223594)
  symbol-value(\223594)
  (cons uid (symbol-value sym))
  (cons (cons uid (symbol-value sym)) retrieve-list)
  (setq retrieve-list (cons (cons uid (symbol-value sym)) retrieve-list))
  (if (or do-full-retrieve (null retrieved-entry)) (setq retrieve-list (cons 
(cons uid (symbol-value sym)) retrieve-list)) (setq remote-expunge-list (cons 
(cons uid uid-validity) remote-expunge-list)))
  (if (boundp (intern uid here)) nil (setq retrieved-entry (vm-find 
vm-imap-retrieved-messages (function (lambda (entry) (and (equal (car entry) 
uid) (equal (car ...) uid-validity)))))) (if (or do-full-retrieve (null 
retrieved-entry)) (setq retrieve-list (cons (cons uid (symbol-value sym)) 
retrieve-list)) (setq remote-expunge-list (cons (cons uid uid-validity) 
remote-expunge-list))))
  (let ((uid (symbol-name sym))) (if (boundp (intern uid here)) nil (setq 
retrieved-entry (vm-find vm-imap-retrieved-messages (function (lambda (entry) 
(and (equal ... uid) (equal ... uid-validity)))))) (if (or do-full-retrieve 
(null retrieved-entry)) (setq retrieve-list (cons (cons uid (symbol-value sym)) 
retrieve-list)) (setq remote-expunge-list (cons (cons uid uid-validity) 
remote-expunge-list)))))
  (lambda (sym) (let ((uid (symbol-name sym))) (if (boundp (intern uid here)) 
nil (setq retrieved-entry (vm-find vm-imap-retrieved-messages (function (lambda 
(entry) (and ... ...))))) (if (or do-full-retrieve (null retrieved-entry)) 
(setq retrieve-list (cons (cons uid (symbol-value sym)) retrieve-list)) (setq 
remote-expunge-list (cons (cons uid uid-validity) 
remote-expunge-list))))))(\223594)
  mapatoms((lambda (sym) (let ((uid (symbol-name sym))) (if (boundp (intern uid 
here)) nil (setq retrieved-entry (vm-find vm-imap-retrieved-messages (function 
(lambda (entry) (and ... ...))))) (if (or do-full-retrieve (null 
retrieved-entry)) (setq retrieve-list (cons (cons uid (symbol-value sym)) 
retrieve-list)) (setq remote-expunge-list (cons (cons uid uid-validity) 
remote-expunge-list)))))) [\223634 \223635 \223636 \223637 \223701 \223745 
\223703 \223704 \223705 \223706 \223707 \223708 \223640 \223641 \223642 \223600 
\223601 \223602 \223603 \223604 \223605 \223649 \223607 \223608 \223609 \223584 
\223585 \223586 \223650 \223588 \223695 \223610 \223611 \223612 \223613 \223614 
\223615 \223590 \223591 \223618 \223619 \223594 \223727 \223596 \223597 \223598 
\223599 \223620 \223621 \223622 ...])
  (let ((here (make-vector 67 0)) there flags (uid-validity 
(vm-folder-imap-uid-validity)) (do-full-retrieve (eq do-retrieves (quote 
full))) retrieve-list remote-expunge-list local-expunge-list stale-list uid mp 
retrieved-entry) (vm-imap-retrieve-uid-and-flags-data) (setq there 
(vm-folder-imap-uid-obarray)) (setq mp vm-message-list) (while mp (cond ((not 
(equal (vm-imap-uid-validity-of (car mp)) uid-validity)) (setq stale-list (cons 
(car mp) stale-list))) ((member "stale" (vm-decoded-labels-of (car mp))) nil) 
(t (setq uid (vm-imap-uid-of (car mp))) (set (intern uid here) (car mp)) (if 
(not (boundp (intern uid there))) (setq local-expunge-list (cons (car mp) 
local-expunge-list))))) (setq mp (cdr mp))) (mapatoms (function (lambda (sym) 
(let ((uid (symbol-name sym))) (if (boundp (intern uid here)) nil (setq 
retrieved-entry (vm-find vm-imap-retrieved-messages ...)) (if (or 
do-full-retrieve ...) (setq retrieve-list ...) (setq remote-expunge-list 
...)))))) there) (setq retrieve-list (sort retrieve-list (function (lambda 
(**pair1 **pair2) (< (cdr **pair1) (cdr **pair2)))))) (list retrieve-list 
remote-expunge-list local-expunge-list stale-list))
  vm-imap-get-synchronization-data(t)
  (let* ((folder-buffer (current-buffer)) (folder-name (buffer-name 
folder-buffer)) (process (vm-folder-imap-process)) (imap-buffer (process-buffer 
process)) (uid-validity (vm-folder-imap-uid-validity)) (imapdrop 
(vm-folder-imap-maildrop-spec)) (folder (or (vm-imap-folder-for-spec imapdrop) 
(vm-safe-imapdrop-string imapdrop))) new-messages (sync-data 
(vm-imap-get-synchronization-data do-retrieves)) (retrieve-list (nth 0 
sync-data)) (remote-expunge-list (nth 1 sync-data)) (local-expunge-list (nth 2 
sync-data)) (stale-list (nth 3 sync-data))) (if save-attributes (progn (let 
((mp vm-message-list) (errors 0)) (vm-inform 6 "%s: Updating attributes on the 
IMAP server... " folder-name) (while mp (if (or (eq save-attributes ...) 
(vm-attribute-modflag-of ...)) (condition-case nil (vm-imap-save-message-flags 
process ...) (vm-imap-protocol-error ... ...))) (setq mp (cdr mp))) (if (> 
errors 0) (vm-inform 3 "%s: Updating attributes on the IMAP server... %d 
errors" folder-name errors) (vm-inform 6 "%s: Updating attributes on the IMAP 
server... done" folder-name))))) (if retrieve-attributes (progn (let ((mp 
vm-message-list) (len (length vm-message-list)) (n 0) uid m mflags) (vm-inform 
6 "%s: Retrieving message attributes and labels... " folder-name) (while mp 
(setq m (car mp)) (setq uid (vm-imap-uid-of m)) (if (and (equal ... 
uid-validity) (vm-folder-imap-uid-msn uid)) (progn (setq mflags ...) 
(vm-imap-update-message-flags m mflags t))) (setq mp (cdr mp) n (1+ n))) 
(vm-inform 6 "%s: Retrieving message atrributes and labels... done" 
folder-name)))) (if (and do-retrieves retrieve-list) (progn (setq new-messages 
(vm-imap-retrieve-messages retrieve-list)))) (if do-local-expunges (progn 
(vm-inform 6 "%s: Expunging messages in cache... " folder-name) 
(vm-expunge-folder :quiet t :just-these-messages local-expunge-list) (if (and 
(eq interactive t) stale-list) (if (y-or-n-p (format "%s: Found %s messages 
with invalid UIDs.  Expunge them? " folder-name (length stale-list))) 
(vm-expunge-folder :quiet t :just-these-messages stale-list) (vm-inform 1 "%s: 
They will be labelled 'stale'" folder-name) (mapc (function (lambda ... ...)) 
stale-list))) (vm-inform 6 "%s: Expunging messages in cache... done" 
folder-name))) (if (and do-remote-expunges (if (eq do-remote-expunges (quote 
all)) (setq vm-imap-messages-to-expunge remote-expunge-list) 
vm-imap-messages-to-expunge)) (progn (vm-imap-expunge-remote-messages))) (setq 
vm-imap-connection-mode (quote online)) new-messages)
  (if (or vm-global-block-new-mail (eq vm-imap-connection-mode (quote offline)) 
(null (vm-re-establish-folder-imap-session interactive "general operation" 
nil))) (vm-imap-server-error "Could not connect to the IMAP server") (if 
do-retrieves (vm-assimilate-new-messages)) (vm-inform 6 "%s: Logging into the 
IMAP server..." (buffer-name)) (let* ((folder-buffer (current-buffer)) 
(folder-name (buffer-name folder-buffer)) (process (vm-folder-imap-process)) 
(imap-buffer (process-buffer process)) (uid-validity 
(vm-folder-imap-uid-validity)) (imapdrop (vm-folder-imap-maildrop-spec)) 
(folder (or (vm-imap-folder-for-spec imapdrop) (vm-safe-imapdrop-string 
imapdrop))) new-messages (sync-data (vm-imap-get-synchronization-data 
do-retrieves)) (retrieve-list (nth 0 sync-data)) (remote-expunge-list (nth 1 
sync-data)) (local-expunge-list (nth 2 sync-data)) (stale-list (nth 3 
sync-data))) (if save-attributes (progn (let ((mp vm-message-list) (errors 0)) 
(vm-inform 6 "%s: Updating attributes on the IMAP server... " folder-name) 
(while mp (if (or ... ...) (condition-case nil ... ...)) (setq mp (cdr mp))) 
(if (> errors 0) (vm-inform 3 "%s: Updating attributes on the IMAP server... %d 
errors" folder-name errors) (vm-inform 6 "%s: Updating attributes on the IMAP 
server... done" folder-name))))) (if retrieve-attributes (progn (let ((mp 
vm-message-list) (len (length vm-message-list)) (n 0) uid m mflags) (vm-inform 
6 "%s: Retrieving message attributes and labels... " folder-name) (while mp 
(setq m (car mp)) (setq uid (vm-imap-uid-of m)) (if (and ... ...) (progn ... 
...)) (setq mp (cdr mp) n (1+ n))) (vm-inform 6 "%s: Retrieving message 
atrributes and labels... done" folder-name)))) (if (and do-retrieves 
retrieve-list) (progn (setq new-messages (vm-imap-retrieve-messages 
retrieve-list)))) (if do-local-expunges (progn (vm-inform 6 "%s: Expunging 
messages in cache... " folder-name) (vm-expunge-folder :quiet t 
:just-these-messages local-expunge-list) (if (and (eq interactive t) 
stale-list) (if (y-or-n-p (format "%s: Found %s messages with invalid UIDs.  
Expunge them? " folder-name ...)) (vm-expunge-folder :quiet t 
:just-these-messages stale-list) (vm-inform 1 "%s: They will be labelled 
'stale'" folder-name) (mapc (function ...) stale-list))) (vm-inform 6 "%s: 
Expunging messages in cache... done" folder-name))) (if (and do-remote-expunges 
(if (eq do-remote-expunges (quote all)) (setq vm-imap-messages-to-expunge 
remote-expunge-list) vm-imap-messages-to-expunge)) (progn 
(vm-imap-expunge-remote-messages))) (setq vm-imap-connection-mode (quote 
online)) new-messages))
  (progn (if vm-buffer-type-debug (setq vm-buffer-type-trail (cons (quote 
synchronize) vm-buffer-type-trail))) (vm-buffer-type:set (quote folder)) 
(vm-imap-init-log) (vm-imap-log-tokens (list (quote synchronize) 
(current-buffer) (vm-folder-imap-process))) (setq vm-buffer-type-trail nil) (if 
(and do-retrieves vm-block-new-mail) (error "Can't get new mail until you save 
this folder")) (if (or vm-global-block-new-mail (eq vm-imap-connection-mode 
(quote offline)) (null (vm-re-establish-folder-imap-session interactive 
"general operation" nil))) (vm-imap-server-error "Could not connect to the IMAP 
server") (if do-retrieves (vm-assimilate-new-messages)) (vm-inform 6 "%s: 
Logging into the IMAP server..." (buffer-name)) (let* ((folder-buffer 
(current-buffer)) (folder-name (buffer-name folder-buffer)) (process 
(vm-folder-imap-process)) (imap-buffer (process-buffer process)) (uid-validity 
(vm-folder-imap-uid-validity)) (imapdrop (vm-folder-imap-maildrop-spec)) 
(folder (or (vm-imap-folder-for-spec imapdrop) (vm-safe-imapdrop-string 
imapdrop))) new-messages (sync-data (vm-imap-get-synchronization-data 
do-retrieves)) (retrieve-list (nth 0 sync-data)) (remote-expunge-list (nth 1 
sync-data)) (local-expunge-list (nth 2 sync-data)) (stale-list (nth 3 
sync-data))) (if save-attributes (progn (let ((mp vm-message-list) (errors 0)) 
(vm-inform 6 "%s: Updating attributes on the IMAP server... " folder-name) 
(while mp (if ... ...) (setq mp ...)) (if (> errors 0) (vm-inform 3 "%s: 
Updating attributes on the IMAP server... %d errors" folder-name errors) 
(vm-inform 6 "%s: Updating attributes on the IMAP server... done" 
folder-name))))) (if retrieve-attributes (progn (let ((mp vm-message-list) (len 
...) (n 0) uid m mflags) (vm-inform 6 "%s: Retrieving message attributes and 
labels... " folder-name) (while mp (setq m ...) (setq uid ...) (if ... ...) 
(setq mp ... n ...)) (vm-inform 6 "%s: Retrieving message atrributes and 
labels... done" folder-name)))) (if (and do-retrieves retrieve-list) (progn 
(setq new-messages (vm-imap-retrieve-messages retrieve-list)))) (if 
do-local-expunges (progn (vm-inform 6 "%s: Expunging messages in cache... " 
folder-name) (vm-expunge-folder :quiet t :just-these-messages 
local-expunge-list) (if (and (eq interactive t) stale-list) (if (y-or-n-p ...) 
(vm-expunge-folder :quiet t :just-these-messages stale-list) (vm-inform 1 "%s: 
They will be labelled 'stale'" folder-name) (mapc ... stale-list))) (vm-inform 
6 "%s: Expunging messages in cache... done" folder-name))) (if (and 
do-remote-expunges (if (eq do-remote-expunges (quote all)) (setq 
vm-imap-messages-to-expunge remote-expunge-list) vm-imap-messages-to-expunge)) 
(progn (vm-imap-expunge-remote-messages))) (setq vm-imap-connection-mode (quote 
online)) new-messages)))
  (progn (let ((--cl-keys-- --cl-rest--)) (while --cl-keys-- (cond ((memq (car 
--cl-keys--) (quote (:interactive :do-remote-expunges :do-local-expunges 
:do-retrieves :save-attributes :retrieve-attributes :allow-other-keys))) (setq 
--cl-keys-- (cdr (cdr --cl-keys--)))) ((car (cdr (memq ... --cl-rest--))) (setq 
--cl-keys-- nil)) (t (error "Keyword argument %s not one of (:interactive 
:do-remote-expunges :do-local-expunges :do-retrieves :save-attributes 
:retrieve-attributes)" (car --cl-keys--)))))) (progn (if vm-buffer-type-debug 
(setq vm-buffer-type-trail (cons (quote synchronize) vm-buffer-type-trail))) 
(vm-buffer-type:set (quote folder)) (vm-imap-init-log) (vm-imap-log-tokens 
(list (quote synchronize) (current-buffer) (vm-folder-imap-process))) (setq 
vm-buffer-type-trail nil) (if (and do-retrieves vm-block-new-mail) (error 
"Can't get new mail until you save this folder")) (if (or 
vm-global-block-new-mail (eq vm-imap-connection-mode (quote offline)) (null 
(vm-re-establish-folder-imap-session interactive "general operation" nil))) 
(vm-imap-server-error "Could not connect to the IMAP server") (if do-retrieves 
(vm-assimilate-new-messages)) (vm-inform 6 "%s: Logging into the IMAP 
server..." (buffer-name)) (let* ((folder-buffer (current-buffer)) (folder-name 
(buffer-name folder-buffer)) (process (vm-folder-imap-process)) (imap-buffer 
(process-buffer process)) (uid-validity (vm-folder-imap-uid-validity)) 
(imapdrop (vm-folder-imap-maildrop-spec)) (folder (or (vm-imap-folder-for-spec 
imapdrop) (vm-safe-imapdrop-string imapdrop))) new-messages (sync-data 
(vm-imap-get-synchronization-data do-retrieves)) (retrieve-list (nth 0 
sync-data)) (remote-expunge-list (nth 1 sync-data)) (local-expunge-list (nth 2 
sync-data)) (stale-list (nth 3 sync-data))) (if save-attributes (progn (let 
(... ...) (vm-inform 6 "%s: Updating attributes on the IMAP server... " 
folder-name) (while mp ... ...) (if ... ... ...)))) (if retrieve-attributes 
(progn (let (... ... ... uid m mflags) (vm-inform 6 "%s: Retrieving message 
attributes and labels... " folder-name) (while mp ... ... ... ...) (vm-inform 6 
"%s: Retrieving message atrributes and labels... done" folder-name)))) (if (and 
do-retrieves retrieve-list) (progn (setq new-messages 
(vm-imap-retrieve-messages retrieve-list)))) (if do-local-expunges (progn 
(vm-inform 6 "%s: Expunging messages in cache... " folder-name) 
(vm-expunge-folder :quiet t :just-these-messages local-expunge-list) (if (and 
... stale-list) (if ... ... ... ...)) (vm-inform 6 "%s: Expunging messages in 
cache... done" folder-name))) (if (and do-remote-expunges (if (eq 
do-remote-expunges ...) (setq vm-imap-messages-to-expunge remote-expunge-list) 
vm-imap-messages-to-expunge)) (progn (vm-imap-expunge-remote-messages))) (setq 
vm-imap-connection-mode (quote online)) new-messages))))
  (let* ((interactive (car (cdr (plist-member --cl-rest-- (quote 
:interactive))))) (do-remote-expunges (car (cdr (plist-member --cl-rest-- 
(quote :do-remote-expunges))))) (do-local-expunges (car (cdr (plist-member 
--cl-rest-- (quote :do-local-expunges))))) (do-retrieves (car (cdr 
(plist-member --cl-rest-- (quote :do-retrieves))))) (save-attributes (car (cdr 
(plist-member --cl-rest-- (quote :save-attributes))))) (retrieve-attributes 
(car (cdr (plist-member --cl-rest-- (quote :retrieve-attributes)))))) (progn 
(let ((--cl-keys-- --cl-rest--)) (while --cl-keys-- (cond ((memq (car 
--cl-keys--) (quote ...)) (setq --cl-keys-- (cdr ...))) ((car (cdr ...)) (setq 
--cl-keys-- nil)) (t (error "Keyword argument %s not one of (:interactive 
:do-remote-expunges :do-local-expunges :do-retrieves :save-attributes 
:retrieve-attributes)" (car --cl-keys--)))))) (progn (if vm-buffer-type-debug 
(setq vm-buffer-type-trail (cons (quote synchronize) vm-buffer-type-trail))) 
(vm-buffer-type:set (quote folder)) (vm-imap-init-log) (vm-imap-log-tokens 
(list (quote synchronize) (current-buffer) (vm-folder-imap-process))) (setq 
vm-buffer-type-trail nil) (if (and do-retrieves vm-block-new-mail) (error 
"Can't get new mail until you save this folder")) (if (or 
vm-global-block-new-mail (eq vm-imap-connection-mode (quote offline)) (null 
(vm-re-establish-folder-imap-session interactive "general operation" nil))) 
(vm-imap-server-error "Could not connect to the IMAP server") (if do-retrieves 
(vm-assimilate-new-messages)) (vm-inform 6 "%s: Logging into the IMAP 
server..." (buffer-name)) (let* ((folder-buffer (current-buffer)) (folder-name 
(buffer-name folder-buffer)) (process (vm-folder-imap-process)) (imap-buffer 
(process-buffer process)) (uid-validity (vm-folder-imap-uid-validity)) 
(imapdrop (vm-folder-imap-maildrop-spec)) (folder (or ... ...)) new-messages 
(sync-data (vm-imap-get-synchronization-data do-retrieves)) (retrieve-list (nth 
0 sync-data)) (remote-expunge-list (nth 1 sync-data)) (local-expunge-list (nth 
2 sync-data)) (stale-list (nth 3 sync-data))) (if save-attributes (progn (let 
... ... ... ...))) (if retrieve-attributes (progn (let ... ... ... ...))) (if 
(and do-retrieves retrieve-list) (progn (setq new-messages ...))) (if 
do-local-expunges (progn (vm-inform 6 "%s: Expunging messages in cache... " 
folder-name) (vm-expunge-folder :quiet t :just-these-messages 
local-expunge-list) (if ... ...) (vm-inform 6 "%s: Expunging messages in 
cache... done" folder-name))) (if (and do-remote-expunges (if ... ... 
vm-imap-messages-to-expunge)) (progn (vm-imap-expunge-remote-messages))) (setq 
vm-imap-connection-mode (quote online)) new-messages)))))
  vm-imap-synchronize-folder(:interactive t :do-local-expunges t :do-retrieves 
t :save-attributes t :retrieve-attributes t)
  vm-get-spooled-mail(t)
  vm-get-new-mail(nil)
  funcall-interactively(vm-get-new-mail nil)
  call-interactively(vm-get-new-mail nil nil)
  command-execute(vm-get-new-mail)