diff -r 000000000000 -r 6474c204b198 js/src/tests/js1_8/genexps/regress-666852.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/js1_8/genexps/regress-666852.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,18 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+
+//-----------------------------------------------------------------------------
+var BUGNUMBER = 665286;
+var summary = 'yield in comprehension RHS';
+var actual = '';
+var expect = '';
+
+function reported() {
+    [1 for (x in yield)]
+}
+
+reportCompare(reported.isGenerator(), true, "reported case: is generator");
+reportCompare(typeof reported(), "object", "reported case: calling doesn't crash");