diff -r 000000000000 -r b1a7da25b547 test/script/basic/JDK-8023368_2.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/script/basic/JDK-8023368_2.js	Wed Apr 27 01:36:41 2016 +0800
@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * JDK-8023368: Instance __proto__ property should exist and be writable.
+ *
+ * @test
+ * @run
+ */
+
+// check Object.setPrototypeOf extension rather than using __proto__
+
+// function to force same callsites
+function check(obj) {
+    print(obj.func());
+    print(obj.x);
+    print(obj.toString());
+}
+
+function Func() {
+}
+
+Func.prototype.func = function() {
+    return "Func.prototype.func";
+}
+
+Func.prototype.x = "hello";
+
+var obj = new Func();
+var obj2 = Object.create(obj);
+
+// check direct and indirect __proto__ change
+check(obj);
+check(obj2);
+Object.setPrototypeOf(obj, {
+   func: function() {
+        return "obj.__proto__.func @ " + __LINE__;
+   },
+   x: 344
+});
+
+check(obj);
+check(obj2);
+
+// check indirect (1 and 2 levels) __proto__ function change
+Object.setPrototypeOf(Object.getPrototypeOf(obj), {
+    toString: function() {
+        return "new object.toString";
+    }
+});
+
+check(obj);
+check(obj2);