diff -r 000000000000 -r 6474c204b198 js/src/tests/js1_6/Array/regress-415540.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/js1_6/Array/regress-415540.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,21 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+//-----------------------------------------------------------------------------
+var BUGNUMBER = 415540;
+var summary = 'Array.push'
+var actual = '';
+var expect = '';
+
+var Constr = function() {};
+Constr.prototype = [];
+var c = new Constr();
+c.push(5);
+c.push(6);
+var actual = Array.push(c,7);
+reportCompare(3, actual, "result of Array.push is length");
+reportCompare(5, c[0], "contents of c[0]");
+reportCompare(6, c[1], "contents of c[1]");
+reportCompare(7, c[2], "contents of c[2]");