The Tor Browser / file revision

 // Test yield* with iter.next and monkeypatching.

 function* g(n) { for (var i=0; i<n; i++) yield i; }

 function* delegate(iter) { return yield* iter; }

 var GeneratorObjectPrototype = Object.getPrototypeOf(g).prototype;

 var GeneratorObjectPrototype_next = GeneratorObjectPrototype.next;

 // Monkeypatch next on an iterator.

 var inner = g(20);

 var outer = delegate(inner);

 assertIteratorNext(outer, 0);

 assertIteratorNext(outer, 1);

 inner.next = function() { return 0; };

 // 42 yielded directly without re-boxing.

 assertEq(0, outer.next());

 // Outer generator not terminated.

 assertEq(0, outer.next());

 // Restore.

 inner.next = GeneratorObjectPrototype_next;

 assertIteratorNext(outer, 2);

 // Repatch.

 inner.next = function() { return { value: 42, done: true }; };

 assertIteratorDone(outer, 42);

 // Monkeypunch next on the prototype.

 var inner = g(20);

 var outer = delegate(inner);

 assertIteratorNext(outer, 0);

 assertIteratorNext(outer, 1);

 GeneratorObjectPrototype.next = function() { return 0; };

 // 42 yielded directly without re-boxing.

 assertEq(0, GeneratorObjectPrototype_next.call(outer));

 // Outer generator not terminated.

 assertEq(0, GeneratorObjectPrototype_next.call(outer));

 // Restore.

 GeneratorObjectPrototype.next = GeneratorObjectPrototype_next;

 assertIteratorNext(outer, 2);

 if (typeof reportCompare == "function")

     reportCompare(true, true);