bug#43597: 28.0.50; arc-mode.el fails to display a ZIP file

[Eli Zaretskii]

> From: Stephen Berman <stephen.berman@gmx.net>
> Cc: 43597@debbugs.gnu.org
> Date: Fri, 25 Sep 2020 14:05:08 +0200
> 
> > With the file I have, replacing -1 by #xffffffff does the job.  So I
> > guess I will need the file you used after all.  It could be either the
> > file's contents, or maybe there are issues related to whether Emacs is
> > a 32-bit (my case) or a 64-bit (your case) program.
> 
> I can't readily make that specific file available to you (I would have
> to get permission to share it), but fortunately the server I downloaded
> it from automatically creates such ZIP files, so I just uploaded two
> small test files to the server and downloaded them as a ZIP file, and it
> shows exactly the same behavior (trying to visit it in archive-mode
> fails with -1 but not with #xffffffff, but with the latter the size of
> each of the files in the archive is given as #xffffffff), so it should
> serve for debugging.  I've attached that ZIP file.

Thanks, with this file I do see the problem.