diff -r 000000000000 -r 6474c204b198 js/src/tests/ecma_6/Generators/delegating-yield-12.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/tests/ecma_6/Generators/delegating-yield-12.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,49 @@
+// yield* calls @@iterator on the iterable to produce the iterator.
+
+var log = '';
+
+function IteratorWrapper(iterator) {
+    return {
+        next: function (val) {
+            log += 'n';
+            return iterator.next(val);
+        },
+
+        throw: function (exn) {
+            log += 't';
+            return iterator.throw(exn);
+        }
+    };
+}
+
+function IterableWrapper(iterable) {
+    var ret = {};
+
+    ret[std_iterator] = function () {
+        log += 'i';
+        return IteratorWrapper(iterable[std_iterator]());
+    }
+
+    return ret;
+}
+
+function* delegate(iter) { return yield* iter; }
+
+var iter = delegate(IterableWrapper([1, 2, 3]));
+assertIteratorNext(iter, 1);
+assertIteratorNext(iter, 2);
+assertIteratorNext(iter, 3);
+assertIteratorDone(iter, undefined);
+
+assertEq(log, 'innnn');
+
+iter = delegate([1, 2, 3]);
+assertIteratorNext(iter, 1);
+assertIteratorNext(iter, 2);
+assertIteratorNext(iter, 3);
+assertIteratorDone(iter, undefined);
+
+assertEq(log, 'innnn');
+
+if (typeof reportCompare == "function")
+    reportCompare(true, true);