diff -r 000000000000 -r 6474c204b198 js/src/tests/js1_8/extensions/regress-455973.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/js1_8/extensions/regress-455973.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,29 @@
+/* -*- 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 = 455973;
+var summary = 'Do not assert: !cx->throwing';
+var actual = '';
+var expect = '';
+
+printBugNumber(BUGNUMBER);
+printStatus (summary);
+ 
+jit(true);
+
+try
+{
+  for (let i = 0; i < 5; ++i) void (this["y" + i] = "");
+  this.__defineGetter__("z", function () { throw 2; });
+  for (let j = 0; j < 2; ++j) { [1 for each (q in this) if ('')]; } 
+}
+catch(ex)
+{
+}
+
+jit(false);
+
+reportCompare(expect, actual, summary);