diff -r 000000000000 -r 6474c204b198 js/src/tests/js1_5/extensions/regress-339685.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/js1_5/extensions/regress-339685.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,27 @@
+/* -*- 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 = 339685;
+var summary = 'Setting __proto__ null should not affect __iterator__';
+var actual = '';
+var expect = 'No Error';
+
+printBugNumber(BUGNUMBER);
+printStatus (summary);
+ 
+var d = { a:2, b:3 };
+
+d.__proto__ = null;
+
+try {
+  for (var p in d)
+    ;
+  actual = 'No Error';
+} catch(e) {
+  actual = e + '';
+}
+
+reportCompare(expect, actual, summary);