--- a/jdk/src/share/classes/com/sun/script/javascript/RhinoScriptEngine.java	Wed Mar 09 18:01:43 2011 -0800
+++ b/jdk/src/share/classes/com/sun/script/javascript/RhinoScriptEngine.java	Thu Mar 10 12:52:24 2011 +0530
@@ -115,6 +115,31 @@
 
         //construct object used to implement getInterface
         implementor = new InterfaceImplementor(this) {
+                protected boolean isImplemented(Object thiz, Class<?> iface) {
+                    Context cx = enterContext();
+                    try {
+                        if (thiz != null && !(thiz instanceof Scriptable)) {
+                            thiz = cx.toObject(thiz, topLevel);
+                        }
+                        Scriptable engineScope = getRuntimeScope(context);
+                        Scriptable localScope = (thiz != null)? (Scriptable) thiz :
+                                                    engineScope;
+                        for (Method method : iface.getMethods()) {
+                            // ignore methods of java.lang.Object class
+                            if (method.getDeclaringClass() == Object.class) {
+                                continue;
+                            }
+                            Object obj = ScriptableObject.getProperty(localScope, method.getName());
+                            if (! (obj instanceof Function)) {
+                                return false;
+                            }
+                        }
+                        return true;
+                    } finally {
+                        cx.exit();
+                    }
+                }
+
                 protected Object convertResult(Method method, Object res)
                                             throws ScriptException {
                     Class desiredType = method.getReturnType();

--- a/jdk/src/share/classes/com/sun/script/util/InterfaceImplementor.java	Wed Mar 09 18:01:43 2011 -0800
+++ b/jdk/src/share/classes/com/sun/script/util/InterfaceImplementor.java	Thu Mar 10 12:52:24 2011 +0530
@@ -82,12 +82,19 @@
         if (iface == null || !iface.isInterface()) {
             throw new IllegalArgumentException("interface Class expected");
         }
+        if (! isImplemented(thiz, iface)) {
+            return null;
+        }
         AccessControlContext accCtxt = AccessController.getContext();
         return iface.cast(Proxy.newProxyInstance(iface.getClassLoader(),
             new Class[]{iface},
             new InterfaceImplementorInvocationHandler(thiz, accCtxt)));
     }
 
+    protected boolean isImplemented(Object thiz, Class<?> iface) {
+        return true;
+    }
+
     // called to convert method result after invoke
     protected Object convertResult(Method method, Object res)
                                    throws ScriptException {

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/javax/script/GetInterfaceTest.java	Thu Mar 10 12:52:24 2011 +0530
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2011, 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.
+ */
+
+/*
+ * @test
+ * @bug 6960211
+ * @summary JavaScript engine allows creation of interface although methods not available.
+ */
+
+import javax.script.*;
+
+public class GetInterfaceTest {
+    public static void main(String[] args) throws Exception {
+        ScriptEngineManager manager = new ScriptEngineManager();
+        ScriptEngine engine = manager.getEngineByName("js");
+
+        if (engine == null) {
+            System.out.println("Warning: No engine engine found; test vacuously passes.");
+            return;
+        }
+
+        // don't define any function.
+        engine.eval("");
+
+        Runnable runnable = ((Invocable)engine).getInterface(Runnable.class);
+        if (runnable != null) {
+            throw new RuntimeException("runnable is not null!");
+        }
+
+        // now define "run"
+        engine.eval("function run() { println('this is run function'); }");
+        runnable = ((Invocable)engine).getInterface(Runnable.class);
+        // should not return null now!
+        runnable.run();
+
+        // define only one method of "Foo2"
+        engine.eval("function bar() { println('bar function'); }");
+        Foo2 foo2 = ((Invocable)engine).getInterface(Foo2.class);
+        if (foo2 != null) {
+            throw new RuntimeException("foo2 is not null!");
+        }
+
+        // now define other method of "Foo2"
+        engine.eval("function bar2() { println('bar2 function'); }");
+        foo2 = ((Invocable)engine).getInterface(Foo2.class);
+        foo2.bar();
+        foo2.bar2();
+    }
+
+    interface Foo {
+        public void bar();
+    }
+
+    interface Foo2 extends Foo {
+        public void bar2();
+    }
+}