bug#47244: 28.0.50; SIGSEGV in long-runnning Emacs

[Eli Zaretskii <eliz@gnu.org>]

> From: Michael Welsh Duggan <mwd@cert.org>
> Cc: "mwd@md5i.com" <mwd@md5i.com>,
>         "47244@debbugs.gnu.org"
>  <47244@debbugs.gnu.org>
> Date: Thu, 18 Mar 2021 14:54:19 -0400
> 
> I do have a gnus demon running in the background:
>   (gnus-demon-add-handler 'gnus-demon-scan-news 5 nil)

Maybe that is the reason that the current buffer is being killed under
our feet, I don't know.

Is the GDB session still alive?  If so, could you show what the
following displays?

  (gdb) p XWINDOW(selected_window)->contents
  (gdb) xtype

If "xtype" says it's a buffer, please type:

  (gdb) xbuffer

and tell what that shows.

> If you want me to set a conditional breakpoint anywhere I can do that in
> hopes of capturing something more useful the next time this happens.

I don't really have an idea where to set such a breakpoint, since I
don't understand how is this buffer killed.  I'm guessing you have
some elaborate hooks set up that succeed in killing the current buffer
while redisplay runs or something, that's how such problems are
usually born.