diff -r 000000000000 -r 6474c204b198 js/src/tests/js1_8_5/extensions/clone-regexp.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/js1_8_5/extensions/clone-regexp.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,33 @@
+// |reftest| skip-if(!xulRuntime.shell)
+// -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+// Any copyright is dedicated to the Public Domain.
+// http://creativecommons.org/licenses/publicdomain/
+
+function testRegExp(b) {
+    var a = deserialize(serialize(b));
+    assertEq(a === b, false);
+    assertEq(Object.getPrototypeOf(a), RegExp.prototype);
+    assertEq(Object.prototype.toString.call(a), "[object RegExp]");
+    for (p in a)
+        throw new Error("cloned RegExp should have no enumerable properties");
+
+    assertEq(a.source, b.source);
+    assertEq(a.global, b.global);
+    assertEq(a.ignoreCase, b.ignoreCase);
+    assertEq(a.multiline, b.multiline);
+    assertEq(a.sticky, b.sticky);
+    assertEq("expando" in a, false);
+}
+
+testRegExp(RegExp(""));
+testRegExp(/(?:)/);
+testRegExp(/^(.*)$/gimy);
+testRegExp(RegExp.prototype);
+
+var re = /\bx\b/gi;
+re.expando = true;
+testRegExp(re);
+re.__proto__ = {};
+testRegExp(re);
+
+reportCompare(0, 0, 'ok');