bug#15778: 24.3; cperl-mode causes emacs to lock up

[Eli Zaretskii <eliz@gnu.org>]

> From: Nathan Trapuzzano <nbtrap@nbtrap.com>
> Cc: 15778@debbugs.gnu.org
> Date: Fri, 01 Nov 2013 08:16:24 -0400
> 
> > Please attach a debugger and show the backtrace.  The file etc/DEBUG
> > explains how to look for a place that infloops, perhaps you could
> > follow that and provide a more detailed information.
> 
> There's an infinite loop somewhere in exec_byte_code.  I've attached the
> backtrace at the point.  Moreover, sending emacs a SIGUSR2 does invoke
> the lisp debugger with the following message:
> 
> Debugger entered--entering a function:
> * #[0 "\301\300\302\"\207" [(0 1) set-match-data evaporate] 3 "\n\n(fn)"]()
> * funcall(#[0 "\301\300\302\"\207" [(0 1) set-match-data evaporate] 3 "\n\n(fn)"])
>   jit-lock-fontify-now(1111 1611)
>   jit-lock-function(1111)
>   redisplay_internal\ \(C\ function\)()
> 
> If this is not enough, I can try to look into it more later.

I cannot reproduce this.  Does it happen in "emacs -Q"?