bug#66546: 30.0.50; save-buffer to write-protected file without backup fails

[Eli Zaretskii]

> From: Jens Schmidt <jschmidt4gnu@vodafonemail.de>
> Cc: 66546@debbugs.gnu.org
> Date: Sat, 21 Oct 2023 22:17:18 +0200
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> >>   (equal buffer-file-name (nth 2 setmodes))
> >> 
> >> could also be true in other cases.
> >
> > It doesn't matter which cases could cause this.  What matters is that
> > only when these two are identical that we need to make sure the file
> > ends up read-only as it was before the call to set-file-modes.
> 
> Makes sense, will do.  In that case, would a plain `equal' be enough to
> compare file paths?

Yes, I think so.