bug#865: 23.0.60; The directory is unsafe today

[Eli Zaretskii]

> Date: Fri, 05 Sep 2008 06:51:30 +0800
> From: Jason Rumney <jasonr@gnu.org>
> CC: 865@emacsbugs.donarmstrong.com, emacs-pretest-bug@gnu.org
> 
> > But in other cases, Emacs could compare the ownership to a UID
> > of some other user, and what will we do then?
> >   
> 
> I can't imagine any Lisp code doing this, as it will not know which 
> other users are on the system.

It's quite easy to enumerate users defined on a system, both on Unix
and Windows.  Also, the user ID could be recorded in a file.  See, for
example, vc-rcs.el, where it checks whether the current user is the
one who locked the file.  (We are lucky that it compares user _names_
rather than UIDs.)