tags 40088 + patch
quit

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> Since the void-variable is getting triggered from
>> backtrace_eval_unrewind, I tried the patch below, which almost seems
>> to fix the problem,
>
> Indeed, the patch looks good (except for the removal of `static` which
> seems like a spurious artifact).

No, the removal is on purpose, because I'm calling default_value from
eval.c, and it's defined in data.c.  But, maybe you thought that because
I didn't add the corresponding declaration in a header file, and...

>> but after continuing from the debugger there's a
>> segfault in GC, so it's definitely not the Right Thing.

... the segfault happens because I forgot to declare default_value in
lisp.h, so its return value got converted to int.  *Forehead slap*

So here's the proper patch.  Eli, is it okay for emacs-27?  As I
mentioned earlier, the underlying bug was present in Emacs 26 and
earlier, but it's only surfaced in Emacs 27 because of debug.el
enhancements.