bug#61326: 30.0.50; Editing fil in zip file without extension save creates new file

[Eli Zaretskii]

> Date: Mon, 06 Feb 2023 18:00:14 +0100
> From:  Adam Sjøgren via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>
> 
> 
> If I open a zip archive in Emacs, I get a listing of files within the
> archive, and I can edit the files by pressing RET, and if I then save
> the file, Emacs updates the archive.
> 
> However, if the zip archive doesn't have ".zip" (or ".jar") at the end
> of the filename, Emacs instead of updating the archive opened, creates a
> new archive with ".zip" added.

AFAIR, Emacs uses the 'zip' program to create or update a zip archive,
and I suspect that the fact the archive has .zip appended is because
that's what the 'zip' program does.

Did you try looking at the command that Emacs invokes when you update
a member of the archive?