[PATCH] dix: don't retrieve the syncEvents tail on an empty list

[Chase Douglas]

On 12/18/2011 09:00 PM, Peter Hutterer wrote:
> An empty list points to itself but syncEvents has the list head only and is
> of a different format than the elements. Thus, casting it to a QdEventPtr
> gives us garbage.
> 
> Segfaults with XTS test case Xlib13/XGrabKeyboard
> 
> Introduced in 7af23259d88f4c28ed21140f82cc03b3724c06bb.
> 
> Reported-by: Aaron Plattner <aplattner at nvidia.com>
> Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>

Reviewed-by: Chase Douglas <chase.douglas at canonical.com>