bug#21802: 25.0.50; segfault in regex.c triggered by an isearch

[Eli Zaretskii]

> From: Dima Kogan <dima@secretsauce.net>
> Date: Sun, 01 Nov 2015 01:36:45 -0800
> 
> Hi. I'm running a recent emacs built from git:
> 
>   https://github.com/emacs-mirror/emacs/commit/6e2a402
> 
> I'm on a Debian machine, running the GTK build of emacs. Segfault
> recipe:
> 
> 1. emacs -Q /tmp/feedgnuplot (source attached)
> 2. M-x cperl-mode
> 3. C-s last if /^exit/ C-s
> 
>    Type out the string "last if /^exit/". It may crash while you're
>    typing it, or it may reach the end of the string in the match on line
>    431. Hit C-s again after you typed it. If it didn't crash already,
>    the extra C-s makes it crash.

Isn't this a duplicate of 21688?