diff -r 000000000000 -r 6474c204b198 js/src/tests/js1_5/GC/regress-313479.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/js1_5/GC/regress-313479.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,37 @@
+/* -*- 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 = 313479;
+var summary = 'Root access in jsnum.c';
+var actual = '';
+var expect = '';
+
+printBugNumber(BUGNUMBER);
+printStatus (summary);
+
+var prepared_string = String(1);
+String(2); // To remove prepared_string from newborn
+
+var likeString = {
+  toString: function() {
+    var tmp = prepared_string;
+    prepared_string = null;
+    return tmp;
+  }
+};
+
+var likeNumber = {
+  valueOf: function() {
+    gc();
+    return 10;
+  }
+}
+
+  var expect = 1;
+var actual = parseInt(likeString, likeNumber);
+printStatus("expect="+expect+" actual="+actual);
+ 
+reportCompare(expect, actual, summary);