diff -r 000000000000 -r 6474c204b198 js/src/tests/ecma_3/Array/15.5.4.8-01.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/ecma_3/Array/15.5.4.8-01.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,43 @@
+/* -*- 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 = 480096;
+var summary = 'Array.lastIndexOf';
+var actual = '';
+var expect = '';
+
+
+//-----------------------------------------------------------------------------
+test();
+//-----------------------------------------------------------------------------
+
+function test()
+{
+  enterFunc ('test');
+  printBugNumber(BUGNUMBER);
+  printStatus (summary);
+
+  expect = '-12';
+  actual = 0;
+  actual += Array.lastIndexOf([2, 3,, 4, 5, 6]);
+  actual += [2, 3,, 4, 5, 6].lastIndexOf();
+  actual += Array.prototype.lastIndexOf.call([2, 3,, 4, 5, 6]);
+  actual += Array.prototype.lastIndexOf.apply([2, 3,, 4, 5, 6], [, -4]);
+  actual += Array.prototype.lastIndexOf.apply([2, 3,, 4, 5, 6], [undefined, -4]);
+  actual += Array.prototype.lastIndexOf.apply([2, 3,, 4, 5, 6], [undefined, -5]);
+  actual += Array.lastIndexOf([2, 3,, 4, 5, 6], undefined);
+  actual += Array.lastIndexOf([2, 3,, 4, 5, 6], undefined, 1);
+  actual += Array.lastIndexOf([2, 3,, 4, 5, 6], undefined, 2);
+  actual += Array.lastIndexOf([2, 3,, 4, 5, 6], undefined);
+  actual += Array.lastIndexOf([2, 3,, 4, 5, 6], undefined, 1);
+  actual += Array.lastIndexOf([2, 3,, 4, 5, 6], undefined, 2);
+
+  actual = String(actual);
+
+  reportCompare(expect, actual, summary);
+
+  exitFunc ('test');
+}