diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/for-of/proxy-2.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/for-of/proxy-2.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,29 @@
+// Basic for-of test with Proxy whose iterator method is a generator.
+
+var arr = ['a', 'b', 'c', 'd'];
+var proxy = Proxy.create({
+    getPropertyDescriptor: function (name) {
+        if (name == 'iterator') {
+            return {
+                configurable: false,
+                enumerable: false,
+                writeable: false,
+                value:  function () {
+                    for (var i = 0; i < arr.length; i++)
+                        yield arr[i];
+                }
+            };
+        }
+
+        // Otherwise, inherit the property from arr.
+        for (var obj = arr; obj; obj = Object.getPrototypeOf(obj)) {
+            var desc = Object.getOwnPropertyDescriptor(obj, name);
+            if (desc)
+                return desc;
+        }
+        return undefined;
+    }
+});
+
+for (var i = 0; i < 2; i++)
+    assertEq([v for (v of proxy)].join(","), "a,b,c,d");