layoutManager: Return null monitor if focusIndex is invalid

https://bugzilla.gnome.org/show_bug.cgi?id=788882

diff --git a/js/ui/layout.js b/js/ui/layout.js
index 6f810395da1153d4fa19be5e7f48b8c830219d76..dcffe479ced4ee17868ffe60c771fea41ab122a3 100644 (file)
--- a/js/ui/layout.js
+++ b/js/ui/layout.js
@@ -557,6 +557,8 @@ var LayoutManager = new Lang.Class({
     },
 
     get focusMonitor() {
+        if (this.focusIndex < 0)
+            return null;
         return this.monitors[this.focusIndex];
     },