bug#57129: 29.0.50; Improve behavior of conditionals in Eshell

[Eli Zaretskii]

> Cc: larsi@gnus.org, 57129@debbugs.gnu.org
> From: Jim Porter <jporterbugs@gmail.com>
> Date: Mon, 15 Aug 2022 11:08:45 -0700
> 
> >> I did notice one weird issue though, and maybe this has something to do
> >> with the problem: on MS Windows, if I run any command with a
> >> $<subcommand>, the second and subsequent times, it warns me about
> >> changing the temp file, e.g.:
> >>
> >>     3Zz80A has changed since visited or saved.  Save anyway? (yes or no)
> >>
> >> This probably shouldn't do that, and it could definitely cause issues in
> >> the tests, which can't prompt the user for things like that.
> > 
> > I guess this means you somehow reuse the same temporary file on
> > MS-Windows?  Maybe change the test a bit so that the file name
> > definitely differs?
> 
> I need to investigate this a bit further, since on GNU/Linux, I get a 
> new temp file every time.

Can you tell how you create these temporary files?  Or point me to the
code which does that?