bug#58042: 29.0.50; ASAN use-after-free in re_match_2_internal

[Eli Zaretskii]

> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> Cc: 58042@debbugs.gnu.org
> Date: Sat, 24 Sep 2022 17:08:12 +0200
> 
> But in general, I think the small string compaction could be a serious
> problem here, as soon as a GC happens while the regexp machine holds
> pointers.

What is the path from regexp match to GC?  The GC was triggered by
redisplay, but how did redisplay start while regexp match was in
progress?  Do you see any code in regexp that could trigger redisplay?