diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/for-of/array-holes-4.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/for-of/array-holes-4.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,13 @@
+// for-of on an Array consults the prototype chain when it encounters a hole.
+
+load(libdir + "iteration.js");
+
+var m = {1: 'peek'};
+var a = [0, , 2, 3];
+a.__proto__ = m;
+var log = [];
+Object.prototype[std_iterator] = Array.prototype[std_iterator];
+for (var x of a)
+    log.push(x);
+assertEq(log[1], 'peek');
+assertEq(log.join(), "0,peek,2,3");