diff -r 000000000000 -r 6474c204b198 js/src/tests/js1_5/Regress/regress-458851.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/js1_5/Regress/regress-458851.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,32 @@
+/* -*- 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 = 458851;
+var summary = 'TM: for-in loops should not skip every other value sometimes';
+var actual = '';
+var expect = '';
+
+printBugNumber(BUGNUMBER);
+printStatus (summary);
+ 
+jit(true);
+
+function f() {
+  var a = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16];
+  var x = 0;
+  for (var i in a) {
+    i = parseInt(i);
+    x++;
+  }
+  print(actual = x);
+}
+
+expect = 16;
+f();
+
+jit(false);
+
+reportCompare(expect, actual, summary);