bug#39962: 27.0.90; Crash in Emacs 27.0.90

[Eli Zaretskii]

> From: Pip Cet <pipcet@gmail.com>
> Date: Wed, 11 Mar 2020 18:53:55 +0000
> Cc: pieter-l@vanoostrum.org, 39962@debbugs.gnu.org, eggert@cs.ucla.edu
> 
> > Did you audit all the users of this function, both direct and
> > indirect?  Some of them are outside of GC.
> 
> Thanks for the comment; I just re-checked, and they look fine to me.

??? Fine in what way?  One of the callers is live_buffer_p, which is
called by valid_lisp_object_p, which is expected to return a special
value for dead buffers.  Your change will break that, no?

IOW, you are changing the semantics of "live buffer", for a reason
that can hardly justify that.  That doesn't sound economical to me; it
will certainly make it much harder for me to agree to make the change
on the release branch.  The problem you are trying to solve is rare
and obscure, since this code was with us since 20 years ago without
anyone bumping into it, so changing it to solve such a rare problem,
and on the release branch on top of that, doesn't sound right to me.

Am I missing something?