Workaround for latex-forward-sexp slowness.

* textmodes/tex-mode.el (latex-forward-sexp): Terminate the loop if
sexp scanning does not move point.

Fixes: debbugs:5734

2 files changed, 10 insertions, 2 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index a09042d9faf..b550c8db7e2 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2012-08-03  João Távora  <joaotavora@gmail.com>
+
+        * textmodes/tex-mode.el (latex-forward-sexp): Terminate the loop
+        if sexp scanning does not move point (Bug#5734).
+
 2012-08-02  Tassilo Horn  <tsdh@gnu.org>
 
         * textmodes/reftex-vars.el (reftex-default-label-alist-entries):
diff --git a/lisp/textmodes/tex-mode.el b/lisp/textmodes/tex-mode.el
index 5571af1ad9b..9a3462773fc 100644
--- a/lisp/textmodes/tex-mode.el
+++ b/lisp/textmodes/tex-mode.el
@@ -1722,9 +1722,12 @@ Mark is left at original location."
   "Like `forward-sexp' but aware of multi-char elements and escaped parens."
   (interactive "P")
   (unless arg (setq arg 1))
-  (let ((pos (point)))
+  (let ((pos (point))
+        (opoint 0))
     (condition-case err
-        (while (/= arg 0)
+        (while (and (/= (point) opoint)
+                    (/= arg 0))
+          (setq opoint (point))
           (setq arg
                 (if (> arg 0)
                     (progn (latex-forward-sexp-1) (1- arg))