--- a/nashorn/src/jdk/nashorn/internal/runtime/linker/JavaAdapterFactory.java	Wed Jan 30 14:57:19 2013 +0100
+++ b/nashorn/src/jdk/nashorn/internal/runtime/linker/JavaAdapterFactory.java	Wed Jan 30 21:15:14 2013 +0530
@@ -286,8 +286,8 @@
 
     private static String getGeneratedClassName(final Class<?> superType, final List<Class<?>> interfaces) {
         // The class we use to primarily name our adapter is either the superclass, or if it is Object (meaning we're
-        // just implementing interfaces), then the first implemented interface.
-        final Class<?> namingType = superType == Object.class ? interfaces.get(0) : superType;
+        // just implementing interfaces or extending Object), then the first implemented interface or Object.
+        final Class<?> namingType = superType == Object.class ? (interfaces.isEmpty()? Object.class : interfaces.get(0)) : superType;
         final Package pkg = namingType.getPackage();
         final String namingTypeName = Type.getInternalName(namingType);
         final StringBuilder buf = new StringBuilder();

--- a/nashorn/test/script/basic/JDK-8006424.js	Wed Jan 30 14:57:19 2013 +0100
+++ b/nashorn/test/script/basic/JDK-8006424.js	Wed Jan 30 21:15:14 2013 +0530
@@ -1,3 +1,26 @@
+/*
+ * 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-8006424 : Passing null or undefined to adapter class constructors results in NPE or ClassCastException
  *

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/test/script/basic/JDK-8007140.js	Wed Jan 30 21:15:14 2013 +0530
@@ -0,0 +1,115 @@
+/*
+ * 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-8007140: Java.extend crashes when attempting to extend java.lang.Object
+ *
+ * @test
+ * @run
+ */
+
+
+// try various Java.extend cases
+
+// Single interface
+var runReached = false;
+var r = new (Java.extend(java.lang.Runnable)) {
+    run: function() {
+        runReached = true;
+    }
+};
+
+r.run();
+if (! runReached) {
+    fail("run was not called");
+}
+
+if (! (r instanceof java.lang.Runnable)) {
+    fail("r is not a Runnable");
+}
+
+// Multiple intefaces
+var runReached = false;
+var actionPerformedReached = false;
+
+var obj = new (Java.extend(java.awt.event.ActionListener, java.lang.Runnable)) {
+    actionPerformed : function(e) {
+        actionPerformedReached = true;
+    },
+
+    run: function() {
+        runReached = true;
+    }
+};
+
+obj.actionPerformed(null);
+if (! actionPerformedReached) {
+    fail("actionPerformed was not called");
+}
+
+obj.run();
+if (! runReached) {
+    fail("run was not called");
+}
+
+if (! (obj instanceof java.lang.Runnable)) {
+    fail("obj is not a Runnable");
+}
+
+if (! (obj instanceof java.awt.event.ActionListener)) {
+    fail("obj is not an ActionListener");
+}
+
+// Single class
+var obj = new (Java.extend(java.lang.Object)) {
+    toString: function() { return "I am an Object"; }
+};
+
+if (! (obj instanceof java.lang.Object)) {
+    fail("obj is not an instance of java.lang.Object");
+}
+
+if (obj.toString() != "I am an Object") {
+    fail("Object.toString did not get called");
+}
+
+// Single class and single interface
+var runReached = false;
+var obj = new (Java.extend(java.lang.Object, java.lang.Runnable)) {
+    run: function() {
+        runReached = true;
+    },
+
+    hashCode: function() {
+        return 12;
+    }
+};
+
+obj.run();
+if (! runReached) {
+    fail("run was not called");
+}
+
+if (obj.hashCode() != 12) {
+    fail("hashCode does not return 12");
+}