diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/collections/iterator-proto-1.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/collections/iterator-proto-1.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,15 @@
+// All iterators of the same collection type share their immediate prototype.
+// Those prototype objects in turn inherit directly from Iterator.prototype.
+
+load(libdir + "iteration.js");
+
+function test(obj0, obj1) {
+    var iter0 = obj0[std_iterator](), iter1 = obj1[std_iterator]();
+    var proto = Object.getPrototypeOf(iter0);
+    assertEq(Object.getPrototypeOf(iter1), proto);
+    assertEq(Object.getPrototypeOf(proto), Iterator.prototype);
+}
+
+test([], [1]);
+test(Map(), Map([[1, 1]]));
+test(Set(), Set([1]));