diff -r 000000000000 -r 6474c204b198 js/src/tests/ecma_5/eval/strict-eval-json-object-repeated-property-name.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/ecma_5/eval/strict-eval-json-object-repeated-property-name.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,44 @@
+// Any copyright is dedicated to the Public Domain.
+// http://creativecommons.org/licenses/publicdomain/
+"use strict";
+
+//-----------------------------------------------------------------------------
+var BUGNUMBER = 657713;
+var summary =
+  "eval JSON parser hack misfires in strict mode, for objects with duplicate " +
+  "property names";
+
+print(BUGNUMBER + ": " + summary);
+
+/**************
+ * BEGIN TEST *
+ **************/
+
+try
+{
+  var r = eval('({"a": 2, "a": 3})');
+  throw new Error("didn't throw, returned " + r);
+}
+catch (e)
+{
+  assertEq(e instanceof SyntaxError, true,
+           "strict mode forbids objects with duplicated property names: " + e);
+}
+
+try
+{
+  var r = Function("'use strict'; return eval('({\"a\": 2, \"a\": 3})');")();
+  throw new Error("didn't throw, returned " + r);
+}
+catch (e)
+{
+  assertEq(e instanceof SyntaxError, true,
+           "strict mode forbids objects with duplicated property names: " + e);
+}
+
+/******************************************************************************/
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
+
+print("Tests complete!");