bug#68940: 29.2; Random crashes in face for char / font

[Gerd Möllmann]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Gerd Möllmann <gerd.moellmann@gmail.com>
>> Cc: 68940@debbugs.gnu.org,  Eli Zaretskii <eliz@gnu.org>
>> Date: Thu, 08 Feb 2024 06:42:14 +0100
>> 
>> Robert Vojta <rvojta@me.com> writes:
>> 
>> > Address sanitizer gave me ...
>> >
>> >   https://gist.github.com/zrzka/3506322a8e4e63fc6b323a48faad8f64
>> >
>> > ... heap user after free in "Automatic GC". When this happened, Emacs
>> > was showing the mentioned init file load error, and weird character.
>> >
>> > Don't know if it's related to my initial issue, if the problem is the
>> > timer & kill, ...
>> 
>> I can't make sense of what is happening here: A marker M is created from
>> Lisp (point-marker), and later GC'd. So far so good, and nrmal, but some
>> later GC then finds M in a member of struct buffer. No idea how that's
>> possible.
>
> Exactly my thoughts.  I suspect that it could be a bug in the address
> sanitizer, perhaps triggered by our quite unique memory management.

Maybe it would be worth upgrading to current LLVM? I think Robert
mentioned he is using LLVM 15 from Apple, and LLVM from Homebrew is now
at 17.0.6.