bug#49723: 28.0.50; Test in coding.c for NUL bytes in filenames is not reliable

[Eli Zaretskii]

> From: Michael Albinus <michael.albinus@gmx.de>
> Cc: Eli Zaretskii <eliz@gnu.org>,  phst@google.com,  49723@debbugs.gnu.org
> Date: Thu, 16 Sep 2021 20:12:09 +0200
> 
> > +** 'expand-file-name' now checks for null bytes in filenames.
> > +The function will now check for null bytes in both NAME and
> > +DEFAULT-DIRECTORY arguments, as well as in the 'default-directory'
> > +buffer-local variable, assuming its value is used.  If null bytes are
> > +found, 'expand-file-name' will signal an error.
> 
> Should this be implemented also in remote file names?

Are we sure remote file names cannot include null bytes?