*fix* Check wmhints for NULL

git-svn-id: http://tint2.googlecode.com/svn/trunk@179 121b4492-b84c-0410-8b4c-0d4edfb3f3cc

src/tint.c

@@ -583,7 +583,7 @@ void event_property_notify (XEvent *e)
 		}
 		else if (at == server.atom.WM_HINTS) {
 			XWMHints* wmhints = XGetWMHints(server.dsp, win);
-			if (wmhints->flags & XUrgencyHint) {
+			if (wmhints && wmhints->flags & XUrgencyHint) {
 				task_urgent = tsk;
 				tick_urgent = 0;
 				time_precision = 1;