diff -r 000000000000 -r 6474c204b198 browser/base/content/test/general/browser_bug427559.js
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/base/content/test/general/browser_bug427559.js Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,40 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * Test bug 427559 to make sure focused elements that are no longer on the page
+ * will have focus transferred to the window when changing tabs back to that
+ * tab with the now-gone element.
+ */
+
+// Default focus on a button and have it kill itself on blur
+let testPage = 'data:text/html,