diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/for-of/semantics-03.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/for-of/semantics-03.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,13 @@
+// Replacing Array.prototype.iterator with a generator affects for-of behavior.
+
+load(libdir + "iteration.js");
+
+Array.prototype[std_iterator] = function* () {
+    for (var i = this.length; --i >= 0; )
+        yield this[i];
+};
+
+var s = '';
+for (var v of ['a', 'b', 'c', 'd'])
+    s += v;
+assertEq(s, 'dcba');