bug#16133: 24.3; copy-file fails on chmod when copying to FAT filesystem

[Eli Zaretskii]

> From: Josh <josh@foxtail.org>
> Date: Sat, 14 Dec 2013 12:46:59 -0800
> Cc: Paul Eggert <eggert@cs.ucla.edu>, Artem Chuprina <ran@lasgalen.net>,
>       16133@debbugs.gnu.org
> 
> On Sat, Dec 14, 2013 at 12:19 PM, Glenn Morris <rgm@gnu.org> wrote:
> > I don't know how we tidy this up for the future though.
> > Add yet another optional argument "error-if-permissions-fail"? Yuck.
> 
> It might be reasonable to error only when the existing
> PRESERVE-UID-GID argument was non-nil.

That argument has nothing to do with mode bits, which is what this bug
is about.