From 1ba014d9dba9b1884d7c889fb726eeeca6ff0634 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Florian=20M=C3=BCllner?= <fmuellner@gnome.org>
Date: Tue, 13 Jun 2017 05:39:06 +0200
Subject: [PATCH] layout: Range-check index before array lookup

findMonitorForActor() may be called before the layoutManager gets
to initialize monitors, so make sure the monitor index is in range
to avoid a warning.

https://bugzilla.gnome.org/show_bug.cgi?id=781471
---
 js/ui/layout.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/js/ui/layout.js b/js/ui/layout.js
index aaf9da536..b1e7f94b0 100644
--- a/js/ui/layout.js
+++ b/js/ui/layout.js
@@ -896,7 +896,10 @@ const LayoutManager = new Lang.Class({
     },
 
     findMonitorForActor: function(actor) {
-        return this.monitors[this.findIndexForActor(actor)];
+        let index = this.findIndexForActor(actor);
+        if (index >= 0 && index < this.monitors.length)
+            return this.monitors[index];
+        return null;
     },
 
     _queueUpdateRegions: function() {