[xmonad] darcs patch: Fix possible head []

[Don Stewart]

sean.escriva:
> On Tue, Jan 06, 2009 at 08:21:15PM +0100, Joachim Breitner wrote:
> > Hi,
> > 
> > there are not many places where head is used in xmonad, but this is one of
> > them. Time to make it safe.
> 
> Interesting. I had noticed an occasional 'Prelude: head empty
> list' message. I wonder if this is the source.
> 

Any such error should be immediately reported, fwiw.