RE: completion-setup-function shouldn't set default-directory to nil

[Drew Adams]

> > (when (and minibuffer-completing-file-name
> >            (file-name-directory mbuf-contents))
> >   (with-current-buffer mainbuf
> >      (setq default-directory (file-name-directory mbuf-contents))))
> 
> Or rather
> 
>   (when minibuffer-completing-file-name
>     (with-current-buffer mainbuf
>        (setq default-directory
>              (file-name-directory (expand-file-name mbuf-contents)))))

I don't know about that. Perhaps you're right.