bug#32226: shadowfile test failures

[Eli Zaretskii]

> From: Michael Albinus <michael.albinus@gmx.de>
> Cc: rgm@gnu.org,  32226@debbugs.gnu.org
> Date: Sat, 21 Jul 2018 14:48:38 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Hmm, I'm not sure I follow.  For the test purposes, you are actually
> > shadowing the files to the current system, right?  If so, the location
> > of the temporary directory is known, right?
> 
> I do both. I shadow the files to the local system ("/<system-name>:") and
> to a remote system ("/method:host:/dir"). For the latter, I mock-up a
> remote temporary directory. This is not possible on MS Windows, because
> I use "/bin/sh" as connection program to that virtual remote host,
> instead of "ssh" or alike.

I don't see why this would be impossible.  The test suite is run from
the MSYS Bash anyway, and if I start Emacs from there, I get this:

  (executable-find "sh")
    => "d:/usr/MSYS/bin/sh.exe"

(even though the directory where sh.exe leaves is not on the
system-wide PATH on my systems, although most other users do place it
on PATH).  So use executable-find to get the absolute file name of the
shell, instead of a literal "/bin/sh", and I think everything else
should "just work", no?

> So you shall declare a usable remote directory via that environment
> variable for the MS WIndows case. If you could give me a recipe how to
> setup a mock-up method for MS Windows - the better!

Does the above fit the bill?  If not, what else is needed for the
mock-up method?