bug#81481: 31.0.91; dired-test-filename-with-newline failures on 32-bit Solaris sparc

> From: Stephen Berman <[email protected]>
> Cc: [email protected],  [email protected],  [email protected]
> Date: Tue, 28 Jul 2026 13:39:16 +0200
> 
> On Tue, 28 Jul 2026 14:03:51 +0300 Eli Zaretskii <[email protected]> wrote:
> 
> > How should I test on Windows, given that my 'ls' is GNU 'ls' and that
> > by default 'ls' is not used on Windows?
> 
> Hm, I thought, evidently mistakenly, that any `ls' program did not work
> on MS-Windows and that's why ls-lisp is used for Dired there.

That's the default, yes.  But MS-Windows ports of GNU 'ls' do exist,
and I have such a port.  So I can use it if necessary for this
testing.

> >                                          Also, Windows doesn't allow
> > file names with embedded newlines.  So what and how should I test?
> 
> Now I'm not sure; if your Windows uses GNU `ls' what happens if you try
> to visit in Dired a directory listing a file name containing a newline,

There cannot be such file names on Windows, because Windows
filesystems don't allow that.

> > The patch LGTM otherwise.
> 
> I'm not sure about that either: in the tests I removed `(skip-when (memq
> system-type '(windows-nt ms-dos)))' because I thought `(skip-unless
> (dired--check-use-ls-dired))' would also skip the tests under Windows,
> but if GNU `ls' can be used there, I guess that wouldn't suffice and the
> skip-when sexp has to be restored?  And `dired--toggle-b-switch' and the
> code in `dired-internal-noselect' for displaying the warning about file
> names with newlines would have to explicitly exclude windows-nt and
> ms-dos?

You can check whether 'ls' is being used by testing
ls-lisp-use-insert-directory-program: its default is nil, but if the
user wants to use a ported 'ls', they can customize it to a non-nil
value.