Re: IMAP and Exchange 2007 - imap-fetch-safe

[Reiner Steib <reinersteib+gmane@imap.cc>]

On Mon, Feb 02 2009, Dave Goldberg wrote:

> Unfortunately I cannot report the same success.  I use XEmacs:
>
> "XEmacs 21.4 (patch 21) \"Educational Television\" [Lucid] (x86_64-unknown-linux, Mule) of Tue Jan  6 2009 on blackbird"

Does anyone have an idea what is different in XEmacs?

Here's the relevant code:

(defun imap-fetch-safe (uids props &optional receive nouidfetch buffer)
  "Like `imap-fetch', but DTRT with Exchange 2007 bug.
However, UIDS here is a cons, where the car is the canonical form
of the UIDS specification, and the cdr is the one which works with
Exchange 2007 or, potentially, other buggy servers.
See `imap-enable-exchange-bug-workaround'."
  ;; The first time we get here for a given, we'll try the canonical
  ;; form.  If we get the known error from the buggy server, set the
  ;; flag buffer-locally (to account for connections to multiple
  ;; servers), then re-try with the alternative UIDS spec.  We don't
  ;; unconditionally use the alternative form, since the
  ;; currently-used alternatives are seriously inefficient with some
  ;; servers (although they are valid).
  ;;
  ;; FIXME:  Maybe it would be cleaner to have a flag to not signal
  ;; the error (which otherwise gives a message), and test
  ;; `imap-failed-tags'.  Also, Other IMAP clients use other forms of
  ;; request which work with Exchange, e.g. Claws does "UID FETCH 1:*
  ;; (UID)" rather than "FETCH UID 1,*".  Is there a good reason not
  ;; to do the same?
  (condition-case data
      ;; Binding `debug-on-error' allows us to get the error from
      ;; `imap-parse-response' -- it's normally caught by Emacs around
      ;; execution of a process filter.
      (let ((debug-on-error t))
	(imap-fetch (if imap-enable-exchange-bug-workaround
			(cdr uids)
		      (car uids))
		    props receive nouidfetch buffer))
    (error
     (if (and (not imap-enable-exchange-bug-workaround)
	      ;; This is the Exchange 2007 response.  It may be more
	      ;; robust just to check for a BAD response to the
	      ;; attempted fetch.
	      (string-match "The specified message set is invalid"
			    (cadr data)))
	 (with-current-buffer (or buffer (current-buffer))
	   (set (make-local-variable 'imap-enable-exchange-bug-workaround)
		t)
	   (imap-fetch (cdr uids) props receive nouidfetch))
       (signal (car data) (cdr data))))))

> and if I don't set imap-enable-exchange-bug-workaround to t, I get
> this backtrace:
>
> Debugger entered--Lisp error: (error "Internal error, tag 13 status BAD code nil text The specified message set is invalid.")
>   signal(error ("Internal error, tag 13 status BAD code nil text The specified message set is invalid."))
>   cerror("Internal error, tag %s status %s code %s text %s" 13 BAD nil "The specified message set is invalid.")
>   apply(cerror "Internal error, tag %s status %s code %s text %s" (13 BAD nil "The specified message set is invalid."))
>   error("Internal error, tag %s status %s code %s text %s" 13 BAD nil "The specified message set is invalid.")
>   imap-parse-response()
>   imap-arrival-filter(#<process "imap<1>" pid 10620 state:run> "ecified message set is invalid.
> \n")
>   accept-process-output(#<process "imap<1>" pid 10620 state:run> 0 100)
>   imap-wait-for-tag(13 nil)
>   imap-send-command-wait("FETCH 1,* UID")
>   imap-fetch("1,*" "UID" nil nouidfetch nil)
>   byte-code("..." [nouidfetch receive props imap-enable-exchange-bug-workaround debug-on-error uids t imap-fetch buffer] 6)
>   imap-fetch-safe(("1,*" . "1,*:*") "UID" nil nouidfetch)
>   nnimap-find-minmax-uid("INBOX" examine)
>   nnimap-retrieve-groups(("INBOX" "Calendar" "Sent Items" "INBOX/Miscellaneous" "INBOX/MessageArchive" "Contacts") "imc")
>   gnus-retrieve-groups(("INBOX" "Calendar" "Sent Items" "INBOX/Miscellaneous" "INBOX/MessageArchive" "Contacts") (nnimap "imc" (nnimap-address "imc.mitre.org") (nnimap-stream starttls) (nnimap-server-port 143) (nnimap-need-unselect-to-notice-new-mail t) (nnimap-nov-is-evil t)))
>   gnus-read-active-file-2(("INBOX" "Calendar" "Sent Items" "INBOX/Miscellaneous" "INBOX/MessageArchive" "Contacts") (nnimap "imc" (nnimap-address "imc.mitre.org") (nnimap-stream starttls) (nnimap-server-port 143) (nnimap-need-unselect-to-notice-new-mail t) (nnimap-nov-is-evil t)))
>   gnus-read-active-file-1((nnimap "imc" (nnimap-address "imc.mitre.org") (nnimap-stream starttls) (nnimap-server-port 143) (nnimap-need-unselect-to-notice-new-mail t) (nnimap-nov-is-evil t)) nil)
>   gnus-read-active-file(nil nil)
>   gnus-setup-news(nil nil nil)
>   byte-code("..." [gnus-slave gnus-current-startup-file gnus-startup-file did-connect level dont-connect gnus-group-quit gnus-run-hooks gnus-startup-hook gnus-make-newsrc-file gnus-dribble-read-file gnus-request-create-group "queue" (nndraft "") "drafts" (nndraft "") gnus-setup-news nil gnus-setup-news-hook gnus-start-draft-setup gnus-group-list-groups gnus-group-first-unread-group gnus-configure-windows group gnus-group-set-mode-line gnus-started-hook gnus-use-dribble-file gnus-agent] 4)
>   gnus-1(nil nil nil)
>   gnus(nil)
>   call-interactively(gnus)
>   command-execute(gnus t)
>   execute-extended-command(nil)
>   call-interactively(execute-extended-command)

Bye, Reiner.
-- 
       ,,,
      (o o)
---ooO-(_)-Ooo---  |  PGP key available  |  http://rsteib.home.pages.de/