Invoking gdb hangs after tweak in comint.el

[martin rudalics]

This change

diff --git a/lisp/comint.el b/lisp/comint.el
index a5fca7e..e5012be 100644
--- a/lisp/comint.el
+++ b/lisp/comint.el
@@ -2081,7 +2081,7 @@ Make backspaces delete the previous character."
                        (prompt-re (concat "\\`" (regexp-quote prompt))))
                   (while (string-match prompt-re string)
                     (setq string (substring string (match-end 0)))))))
-            (while (string-match (concat "\\(^" comint-prompt-regexp
+            (while (string-match (concat "\\(" comint-prompt-regexp
                                          "\\)\\1+")
                                  string)
               (setq string (replace-match "\\1" nil nil string)))

hangs Emacs indefinitely when I invoke gdb via say

M-x gdb -i=mi home/martin/emacs-git/trunk/obj-gtk/src/emacs

and I subsequently have to kill the Emacs process with the task
manager.

I have reverted that tweak for now.  Please consider a different
solution.

Thanks in advance, martin