diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/proxy/testDirectProxyHas6.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/proxy/testDirectProxyHas6.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,12 @@
+/*
+ * Don't throw a type error if the trap reports an undefined property as
+ * non-present, regardless of extensibility.
+ */
+var target = {};
+Object.preventExtensions(target);
+assertEq(
+    'foo' in new Proxy(target, {
+        has: function (target, name) {
+            return false;
+        }
+    }), false);