diff -r 000000000000 -r 6474c204b198 js/src/tests/ecma_5/extensions/strict-option-redeclared-parameter.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/ecma_5/extensions/strict-option-redeclared-parameter.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,30 @@
+/*
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/licenses/publicdomain/
+ */
+
+//-----------------------------------------------------------------------------
+var BUGNUMBER = 630770;
+var summary =
+  'Correctly warn about duplicate parameters when the strict option is enabled';
+
+print(BUGNUMBER + ": " + summary);
+
+/**************
+ * BEGIN TEST *
+ **************/
+
+// Verify that duplicate parameters, with the strict option set, don't provoke
+// an assertion.  Ideally we'd also verify that we warn exactly once per
+// duplicated parameter name, but at present there's no way to test that
+// without more effort (further customizing the shell JSErrorReporter) than we
+// want to make now.
+options("strict");
+eval("function a(x, x, x, x) { }");
+
+/******************************************************************************/
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);
+
+print("All tests passed!");