bug#18912: 24.4; mode-line corruption on graphical frames in dual-headed display

[Eli Zaretskii]

> Date: Tue, 04 Nov 2014 18:14:47 -0200
> From: Bruno Félix Rezende Ribeiro <oitofelix@gnu.org>
> CC: 18912@debbugs.gnu.org
> 
> > I'm not yet convinced that Emacs can do _anything_ to provide a 
> > workaround for this problem.  See my other messages as to why.
> 
> Why do you think my proposed workaround wouldn't work?  My answers to
> your other messages, and your commentaries, seem to suggest Emacs can
> help to work around this.

Then try this:

  (add-hook 'pre-command-hook 'force-mode-line-update)

(I'm not holding my breath.)