bug#58334: 29.0.50; ASAN heap use after free in gui_produce_glyphs

[Eli Zaretskii]

> From: Po Lu <luangruo@yahoo.com>
> Cc: gerd.moellmann@gmail.com,  58334@debbugs.gnu.org
> Date: Fri, 07 Oct 2022 20:16:43 +0800
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > You don't need process_pending_signals, it's enough that some hook
> > calls 'redisplay' from Lisp.
> 
> process_pending_signals called from probably_quit and unblock_input
> calling handle_async_input, and thus gobble_input, is what will run that
> hook calling redisplay, right?

I meant that the problem is much wider and more general: any Lisp can
call redisplay at will.  And we call Lisp from C all over the place.