diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug642206.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug642206.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,30 @@
+this.__proto__ = null;
+
+function testLenientAndStrict(code, lenient_pred, strict_pred) {
+  return (strict_pred("'use strict'; " + code) && 
+          lenient_pred(code));
+}
+function raisesException(exception) {
+  return function (code) {
+    try {
+      eval(code);
+    } catch (actual) {
+    }
+  };
+};
+try {
+function arr() {
+  return Object.defineProperty(Object()* delete Object, 0, {writable: false});
+}
+assertEq(testLenientAndStrict('var a = arr(); [a.splice(0, 1), a]',
+                              raisesException(TypeError),
+                              raisesException(TypeError)),
+         true);
+} catch (e) {}
+ForIn_2(this);
+function ForIn_2(object) {
+  for ( property in object ) {
+    with ( object ) {
+    }
+  }
+}