diff --git a/js/tests/js1_5/String/regress-314890.js b/js/tests/js1_5/String/regress-314890.js
new file mode 100755
index 000000000000..66b459ac2850
--- /dev/null
+++ b/js/tests/js1_5/String/regress-314890.js
@@ -0,0 +1,81 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is JavaScript Engine testing utilities.
+ *
+ * The Initial Developer of the Original Code is
+ * Mozilla Foundation.
+ * Portions created by the Initial Developer are Copyright (C) 2005
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s): Jeff Thompson 
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+//-----------------------------------------------------------------------------
+var bug = 314890;
+var summary = 'String == should short circuit for object identify';
+var actual = '';
+var expect = '';
+
+printBugNumber (bug);
+printStatus (summary);
+
+var s1 = 'x';
+var s2;
+var count = 0;
+
+var data = {X:[], Y:[]};
+for (var power = 0; power < 20; power++)
+{  
+  s1 = s1 + s1;
+  s2 = s1;
+
+  data.X.push(s1.length);
+  var start = new Date();
+  for (var count = 0; count < 1000; count++)
+  {
+    if (s1 == s2)
+    {
+      ++count;
+    }
+  }
+  var stop = new Date();
+  data.Y.push(stop - start);
+}
+
+var order = BigO(data);
+
+var msg = '';
+for (var p = 0; p < data.X.length; p++)
+{ 
+  msg += '(' + data.X[p] + ', ' + data.Y[p] + '); ';
+}
+printStatus(msg);
+printStatus('Order: ' + order);
+reportCompare(true, order < 1, 'BigO ' + order + ' < 1');
+
+reportCompare(expect, actual, summary);
+