diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/for-of/semantics-04.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/for-of/semantics-04.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,17 @@
+// Giving an Array an own .iterator property affects for-of.
+
+load(libdir + "asserts.js");
+load(libdir + "iteration.js");
+
+var a = [];
+a[std_iterator] = function* () {
+    yield 'o';
+    yield 'k';
+};
+var s = '';
+for (var v of a)
+    s += v;
+assertEq(s, 'ok');
+
+a[std_iterator] = undefined;
+assertThrowsInstanceOf(function () { for (var v of a) ; }, TypeError);