--- a/src/share/classes/javax/swing/plaf/basic/BasicViewportUI.java	Thu May 20 20:42:56 2010 +0400
+++ b/src/share/classes/javax/swing/plaf/basic/BasicViewportUI.java	Fri May 21 22:04:35 2010 +0400
@@ -56,8 +56,8 @@
     }
 
     public void uninstallUI(JComponent c) {
+        uninstallDefaults(c);
         super.uninstallUI(c);
-
     }
 
     protected void installDefaults(JComponent c) {

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/javax/swing/JViewport/6953396/bug6953396.java	Fri May 21 22:04:35 2010 +0400
@@ -0,0 +1,64 @@
+/*
+ * Copyright 2010 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+/* @test
+ * @bug 6953396
+ * @summary javax.swing.plaf.basic.BasicViewportUI.uninstallDefaults() is not called when UI is uninstalled
+ * @author Alexander Potochkin
+ */
+
+import javax.swing.*;
+import javax.swing.plaf.basic.BasicViewportUI;
+
+public class bug6953396 {
+    static volatile boolean flag;
+
+    public static void main(String[] args) throws Exception {
+        SwingUtilities.invokeAndWait(new Runnable() {
+            @Override
+            public void run() {
+                BasicViewportUI ui = new BasicViewportUI() {
+
+                    @Override
+                    protected void installDefaults(JComponent c) {
+                        super.installDefaults(c);
+                        flag = true;
+                    }
+
+                    @Override
+                    protected void uninstallDefaults(JComponent c) {
+                        super.uninstallDefaults(c);
+                        flag = false;
+                    }
+                };
+
+                JViewport viewport = new JViewport();
+                viewport.setUI(ui);
+                viewport.setUI(null);
+            }
+        });
+        if (flag) {
+            throw new RuntimeException("uninstallDefaults() hasn't been called");
+        }
+    }
+}