diff -r 000000000000 -r 6474c204b198 js/src/tests/ecma_5/Exceptions/error-expando-reconfigure.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/ecma_5/Exceptions/error-expando-reconfigure.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,28 @@
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/
+ */
+
+var gTestfile = "error-expando-reconfigure.js"
+//-----------------------------------------------------------------------------
+var BUGNUMBER = 961494;
+var summary =
+  "Reconfiguring the first expando property added to an Error object " +
+  "shouldn't assert";
+
+print(BUGNUMBER + ": " + summary);
+
+/**************
+ * BEGIN TEST *
+ **************/
+
+var err = new Error(); // no message argument => no err.message property
+err.expando = 17;
+Object.defineProperty(err, "expando", { configurable: false });
+
+/******************************************************************************/
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
+
+print("Tests complete");