bug#7952: 24.0.50; crash in find_interval

[Eli Zaretskii]

> From: Chong Yidong <cyd@stupidchicken.com>
> Cc: Eli Zaretskii <eliz@gnu.org>, 7952@debbugs.gnu.org
> Date: Wed, 13 Apr 2011 17:06:32 -0400
> 
> Unfortunately, this is a change in only compile.el, which means the
> problem somewhere in the C code did not originate in this commit, and is
> only triggered by it.

Do you succeed in understanding how the problem in intervals.c came
into existence?  E.g., did something change BUF_BEG behind the back of
intervals.c?  How about adding some tracing code to intervals.c and
see what comes up there?

Btw, does this problem happen only while grep-find runs, or also after
it exits?