diff -r 000000000000 -r 6474c204b198 js/src/tests/js1_8/genexps/regress-667131.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/js1_8/genexps/regress-667131.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,54 @@
+/* -*- 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 = 667131;
+var summary = 'yield ignored if maybeNoteLegacyGenerator called too late';
+var actual = '';
+var expect = '';
+
+function testGenerator(f, desc) {
+    reportCompare(f.isGenerator(), true, desc + ": is generator");
+    reportCompare(typeof f(), "object", desc + ": calling doesn't crash");
+}
+
+function reported1() {
+    (function(){})([yield[]], (""))
+}
+
+function reported2() {
+    (function(){})(let(w = "") yield, (e))
+}
+
+function simplified1() {
+    print([yield], (0))
+}
+
+function simplified2() {
+    print(let(w) yield, (0))
+}
+
+function f1(a) { [x for (x in yield) for (y in (a))] }
+function f2(a) { [x for (x in yield) if (y in (a))] }
+function f3(a) { ([x for (x in yield) for (y in (a))]) }
+function f4(a) { ([x for (x in yield) if (y in (a))]) }
+
+function f7() { print({a:yield},(0)) }
+
+function f8() { ([yield], (0)) }
+function f9() { (let(w)yield, (0)) }
+
+testGenerator(reported1, "reported function with array literal");
+testGenerator(reported2, "reported function with let-expression");
+testGenerator(simplified1, "reported function with array literal, simplified");
+testGenerator(simplified2, "reported function with let-expression, simplified");
+testGenerator(f1, "top-level array comprehension with paren expr in for-block");
+testGenerator(f2, "top-level array comprehension with paren expr in if-block");
+testGenerator(f3, "parenthesized array comprehension with paren expr in for-block");
+testGenerator(f4, "parenthesized array comprehension with paren expr in if-block");
+testGenerator(f7, "object literal");
+testGenerator(f8, "array literal in paren exp");
+testGenerator(f9, "let-expression in paren exp");