bug#71712: 29.3; Crash on OpenBSD

[Eli Zaretskii <eliz@gnu.org>]

> Date: Wed, 26 Jun 2024 10:11:04 +0100
> From: Kirill A. Korinsky <kirill@korins.ky>
> Cc: luangruo@yahoo.com,
> 	71712@debbugs.gnu.org
> 
> 
> I had upgraded to 29.4, and it had crashed one more time.
> 
> This time the crash had happened when I make a commit into large git
> repository via magit.
> 
> I write commits message in new frame, and after pressing c c to open a frame
> to write commit message, I had switched to another virtual desktop.
> 
> When I've switched back, I hadn't find emacs, but .core was here with the
> same stack trace.
> 
> Inside magit's commit message buffere I use markdown mode.

The way to find the culprit in these cases is to run the recipe with a
watchpoint on the frame cache's 'used' count, and see which code
causes it to be zeroed.  Usually, it is some crazy Lisp run from one
of the hooks which we so graciously offer for grabs.  The tricky part
is to find that code and/or the recipe which could be used to
reproduce the problem at will, which I understand you don't have...