bug#10483: 24.0.92; cperl-indent-exp hangs

[Eric Hanchrow <eric.hanchrow@gmail.com>]

Please describe exactly what actions triggered the bug, and
the precise symptoms of the bug.  If you can, give a recipe
starting from `emacs -Q':

1. Save the following to (e.g.) /tmp/bug.el:

===8<======8<======8<======8<======8<======8<======8<======8<======8<===
    (switch-to-buffer "frotz.pl")
    (cperl-mode)
    (insert "poop ('foo', \n      'bar')")
    ;(insert ";")
    (goto-char 5)
    (cperl-indent-exp)
===8<======8<======8<======8<======8<======8<======8<======8<======8<===

2.  Invoke emacs like "emacs -Q --load /tmp/bug.el".

3.  Note that Emacs has hung.

If you'd like ...

4.  Kill the hung emacs

5.  Uncomment the fourth line in bug.el

6. Invoke emacs the same way again

7. Note that Emacs is perfectly happy.

If Emacs crashed, and you have the Emacs process in the gdb debugger,
please include the output from the following gdb commands:
    `bt full' and `xbacktrace'.
For information about debugging Emacs, please read the file
/home/ehanchrow/local/emacs-master-gui/share/emacs/24.0.92/etc/DEBUG.


In GNU Emacs 24.0.92.3 (x86_64-unknown-linux-gnu, GTK+ Version 2.20.1)
 of 2012-01-03 on rampage.sea
Windowing system distributor `The X.Org Foundation', version 11.0.10402000
configured using `configure  '--prefix=/home/ehanchrow/local/emacs-master-gui''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: C
  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
  value of $XMODIFIERS: nil
  locale-coding-system: utf-8-unix
  default enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
M-x r e p o r t - e m a c s - b u g <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr message format-spec rfc822 mml easymenu
mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231 rfc2047 rfc2045
ietf-drums mm-util mail-prsvr mailabbrev mail-utils gmm-utils mailheader
emacsbug time-date tooltip ediff-hook vc-hooks lisp-float-type mwheel
x-win x-dnd tool-bar dnd fontset image fringe lisp-mode register page
menu-bar rfn-eshadow timer select scroll-bar mouse jit-lock font-lock
syntax facemenu font-core frame cham georgian utf-8-lang misc-lang
vietnamese tibetan thai tai-viet lao korean japanese hebrew greek
romanian slovak czech european ethiopic indian cyrillic chinese
case-table epa-hook jka-cmpr-hook help simple abbrev minibuffer loaddefs
button faces cus-face files text-properties overlay sha1 md5 base64
format env code-pages mule custom widget hashtable-print-readable
backquote make-network-process dbusbind dynamic-setting
system-font-setting font-render-setting move-toolbar gtk x-toolkit x
multi-tty emacs)