Subject: 24.4.50; user-uid no longer set

From: Paul Eggert <[email-masked]>
Date: Sun, 03 Aug 2014 22:55:20 -0700

All the uses I see of this idiom treat it as a function.  E.g., 
<http://www.emacswiki.org/emacs/AutoSave> says:

     (defconst emacs-tmp-dir
       (format "%s/%s%s/" temporary-file-directory "emacs" (user-uid)))