bug#74966: 31.0.50; Crash report (using igc on macOS)

[Eli Zaretskii <eliz@gnu.org>]

> Date: Fri, 20 Dec 2024 16:40:52 +0000
> From: Pip Cet <pipcet@protonmail.com>
> Cc: Gerd Möllmann <gerd.moellmann@gmail.com>, Eli Zaretskii <eliz@gnu.org>, acorallo@gnu.org, spd@toadstyle.org, 74966@debbugs.gnu.org
> 
> I meant this patch, which splits "doc" into "doc_index" and
> "doc_offset".  It'd probably be better to use a Lisp_Object here, which
> can be either a fixnum (index into etc/DOC) or a string (the doc string
> specified in some other manner).  And maybe we can drop the docfile
> index thing entirely at some point soon?

TBH, I'd be much happier without splitting 'doc' into two members.
Isn't it possible to avoid overwriting 'doc', thus avoiding the crash,
without splitting the member in two?

DOC handling in Emacs is extremely complex and has many subtle
aspects.  Experience teaches us that bugs in this area sometimes take
years to report and fix.  Splitting a member into two risks
introducing bugs because we might use the wrong member in some
situation(s).  The test suite's coverage of doc.c and features related
to doc strings is still rudimentary, so we cannot be sure any such
bugs will be caught in time by the tests.  Which is why I hope we can
avoid splitting this member in two.

Thanks.