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

> From: Stephen Berman <[email protected]>
> Cc: Eli Zaretskii <[email protected]>,  [email protected], john muhl
>  <[email protected]>
> Date: Mon, 27 Jul 2026 23:51:29 +0200
> 
> > I think this is correct, but I think the fix, both for the test failures
> > and for deciding whether to display the warning and suggest changing the
> > the Dired display, is to use `dired-use-ls-dired', as was considered
> > earlier on in that other bug report
> > (https://debbugs.gnu.org/cgi/bugreport.cgi?bug=80499#145), instead
> > testing for ls support of -b.  I'll post a patch later.
> 
> The patch is attached.  If I made no mistake, the tests
> dired-test-filename-with-newline-1 and
> dired-test-filename-with-newline-2 should now be skipped on platforms
> using an `ls' that does not support the --dired switch, and on such
> platforms no warning should be displayed when visiting in Dired a
> directory listing a file name containing a newline with
> `dired-auto-toggle-b-switch' set to nil (the default), and setting this
> user option to t should have no effect on such platforms.  Paul, can you
> confirm for Solaris, and John Muhl (Cc'd), can you confirm for Alpine,
> and Eli, can you confirm for MS-Windows?  (On platforms with an `ls'
> that supports --dired, the behavior with the patch should be unchanged
> from the behavior with the current code; I've confirmed this for my
> GNU/Linux system.)

How should I test on Windows, given that my 'ls' is GNU 'ls' and that
by default 'ls' is not used on Windows?  Also, Windows doesn't allow
file names with embedded newlines.  So what and how should I test?

The patch LGTM otherwise.

> Eli, if you, Paul and John confirm as requested, can this patch go into
> emacs-31?

Yes.