> From: Tino Calancha <tino.calancha@gmail.com>
> Date: Fri, 4 Aug 2017 14:21:01 +0900 (JST)
> cc: Tino Calancha <tino.calancha@gmail.com>,
>     Emacs developers <emacs-devel@gnu.org>
>
> > maybe if you could explain the idea behind the code I could think of a
> > reason why it doesn't work here.
> I added more comments and sanity checks in commit
> db5d38ddb0de83d8f920b7a128fe3fd5156fdf85
> (Fix 2 tests that fail in MS-Windows)
> Does it work now in Windows?

It didn't, but given the comments I've now succeeded to understand the
idea of dired-test-bug25609, and fixed it.

dired-test-bug27631 still fails, and it fails because of this:

          (setq buf (dired (expand-file-name "dir*/*.txt" dir)))

ls-lisp signals an error here:

   wrong-type-argument listp "dir*/*.txt"

Didn't you add a feature lately that should support this in ls-lisp?
I guess that feature needs to be turned on for this test to pass on
Windows.