Infinite, non-breakable loop in imenu [PATCH]

[Kim F. Storm]

Please describe exactly what actions triggered the bug
and the precise symptoms of the bug:

emacs -q

Eval:
(add-hook 'texinfo-mode-hook '(lambda () (imenu-add-to-menubar 
"Texinfo-Sections")))

C-x C-f lispref/syntax.texi RET


Emacs is non-responsive, basta!


It seems related to this change:

2004-10-26  Daniel Pfeiffer  <address@hidden>

        * imenu.el (imenu--generic-function): Skip matches in comments.



The problem is that imenu--generic-function loops because it starts
the re-search-backward in the same position on every pass.
And for some reason, C-g doesn't break the loop.

Here is a fix for both problems.  It works for me, but please review.



*** imenu.el    04 Nov 2004 15:50:52 +0100      1.103
--- imenu.el    12 Nov 2004 23:59:15 +0100      
***************
*** 808,821 ****
                  (index (nth 2 pat))
                  (function (nth 3 pat))
                  (rest (nthcdr 4 pat))
                  cs)
              ;; Go backwards for convenience of adding items in order.
!             (goto-char (point-max))
!             (while (re-search-backward regexp nil t)
                (goto-char (match-end index))
-               (setq beg (match-beginning index))
                (if (setq cs (save-match-data (comment-beginning)))
!                   (goto-char cs)      ; skip this one, it's in a comment
                  (goto-char beg)
                  (imenu-progress-message prev-pos nil t)
                  ;; Add this sort of submenu only when we've found an
--- 808,825 ----
                  (index (nth 2 pat))
                  (function (nth 3 pat))
                  (rest (nthcdr 4 pat))
+                 (next-pos (point-max))
                  cs)
              ;; Go backwards for convenience of adding items in order.
!             (while (and (> next-pos (point-min))
!                         (not quit-flag)
!                         (progn (goto-char next-pos)
!                                (re-search-backward regexp nil t)))
!               (setq beg (match-beginning index)
!                     next-pos (max (point) (1- beg)))
                (goto-char (match-end index))
                (if (setq cs (save-match-data (comment-beginning)))
!                   (setq next-pos (min next-pos cs))   ; skip this one, it's 
in a comment
                  (goto-char beg)
                  (imenu-progress-message prev-pos nil t)
                  ;; Add this sort of submenu only when we've found an




In GNU Emacs 21.3.50.63 (i686-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2004-11-12 on kfs-l.imdomain.dk
Distributor `The XFree86 Project, Inc', version 11.0.40300000
configured using `configure 'CFLAGS=-DUSE_LSB_TAGS=1 -g -Wall''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8
  default-enable-multibyte-characters: t

--
Kim F. Storm  http://www.cua.dk