bug#18891: Doesn't handle pwd = /C: very well

[Eli Zaretskii]

> From: Michael Albinus <michael.albinus@gmx.de>
> Cc: rgm@gnu.org,  monnier@iro.umontreal.ca,  18891@debbugs.gnu.org
> Date: Fri, 07 Nov 2014 17:58:30 +0100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Your change calls Ffile_accessible_directory_p, Fstring_match, and
> > Fsubstring with a unibyte (encoded) string as their argument.  I think
> > we should avoid that, as, e.g., Fstring_match might yield a false
> > positive under some encodings.
> 
> Shall I change it like this?

Yes, I think this is much better.  Thanks.