diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/collections/Map-clear-5.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/collections/Map-clear-5.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,14 @@
+// Map.clear is unaffected by deleting/monkeypatching Map.prototype.{delete,iterator}.
+
+var data = [["a", 1], ["b", 2]];
+var m1 = Map(data), m2 = Map(data);
+
+delete Map.prototype.delete;
+delete Map.prototype.iterator;
+m1.clear();
+assertEq(m1.size, 0);
+
+Map.prototype.delete = function () { throw "FAIL"; };
+Map.prototype.iterator = function () { throw "FAIL"; };
+m2.clear();
+assertEq(m2.size, 0);