diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/for-of/semantics-07.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/for-of/semantics-07.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,17 @@
+// Deleting the .next method of an iterator in the middle of a for-of loop
+// causes a TypeError at the next iteration.
+
+load(libdir + "asserts.js");
+load(libdir + "iteration.js");
+
+var iterProto = Object.getPrototypeOf([][std_iterator]());
+var s = '';
+assertThrowsInstanceOf(function () {
+    for (var v of ['duck', 'duck', 'duck', 'goose', 'FAIL']) {
+        s += v;
+        if (v === 'goose')
+            delete iterProto.next;
+        s += '.';
+    }
+}, TypeError);
+assertEq(s, 'duck.duck.duck.goose.');