bug#58956: mark_object, mark_objects(?) crash

[Eli Zaretskii]

> Date: Sat, 5 Nov 2022 13:54:54 -0700
> Cc: vincent@vinc17.net, spwhitton@spwhitton.name, 58956@debbugs.gnu.org,
>  1017711@bugs.debian.org
> From: Paul Eggert <eggert@cs.ucla.edu>
> 
> On 2022-11-04 00:00, Eli Zaretskii wrote:
> > We need to establish what is the
> > source of SIGHUP in these cases.  "These cases" mean, AFAIU, the
> > situations where Emacs launched an async subprocess to do native
> > compilation (which is another Emacs process in a --batch session), and
> > the parent Emacs session is terminated by the user before the async
> > compilation runs to completion.  Would the child Emacs process get
> > SIGHUP in this scenario?
> 
> Hard for me to say. It's a messy area, with kernels (and Emacs itself) 
> sending SIGHUP on various whims.

But is it possible for a program like Emacs to get SIGHUP in such a
situation, or is that highly improbable?  We have standard streams of
the inferior Emacs process connected via PTYs to the parent process, I
believe -- does that deliver SIGHUP or SIGPIPE when the parent exits?

> Does the attached patch fix things? It builds on your commit 
> 190a6853708ab22072437f6ebd93beb3ec1a9ce6 dated 2020-12-04; I don't know 
> why that earlier patch was installed, but it would seem to apply to 
> SIGHUP and SIGTERM as well as it applies to SIGINT.

I was trying to be conservative, that's all.  I'm okay with doing the
same for SIGHUP.  Vincent, can you try this patch, please?