Hi!

> I haven't had time to see what actually happens in the code, though.
> However,
> > the " if (STRING_MULTIBYTE (file))" looks suspicious as the decoded
> value needs
> > to be checked even for strings like "a". (However, I don't really know
> what
> > STRING_MULTIBYTE does.)
>
> Does removing the STRING_MULTIBYTE test make it work?
>

Yes, it does:

(file-name-all-completions "a" ".")
("aaosecond.txt")

    -- Anders