bug#66744: 30.0.50; Emacs crashes when re-dumping into the same dump file another Emacs instance is using

[Eli Zaretskii]

> Cc: 66744@debbugs.gnu.org
> From: Gerd Möllmann <gerd.moellmann@gmail.com>
> Date: Thu, 26 Oct 2023 17:45:49 +0200
> 
> The linux man page for mmap says, according to Google,
> 
>   MAP_PRIVATE
>        ...
>       It is unspecified whether changes made to the file
>       after the mmap() call are visible in the mapped region.
> 
> So, if the changes made to the dump file in step 3 are visible in the
> mmaped dump file that Emacs from step 2 uses, that would be a bit
> suboptimal :-).

Emacs on GNU/Linux doesn't use mmap, we stopped doing this many years
ago.

It could be relevant to MS-Windows, which emulates mmap and uses the
relevant code in Emacs.  But Ihor doesn't use MS-Windows, AFAIK.