diff --git a/src/share/classes/com/sun/java/swing/plaf/gtk/GTKFileChooserUI.java b/src/share/classes/com/sun/java/swing/plaf/gtk/GTKFileChooserUI.java
index d338c08d6fd8c9c0d14055d085d4e271fbcaa322..a640862c50c506db7c3b8c55a5386516fdb598dc 100644
--- a/src/share/classes/com/sun/java/swing/plaf/gtk/GTKFileChooserUI.java
+++ b/src/share/classes/com/sun/java/swing/plaf/gtk/GTKFileChooserUI.java
@@ -97,14 +97,11 @@ class GTKFileChooserUI extends SynthFileChooserUI {
     private static final Dimension hstrut3 = new Dimension(3, 1);
     private static final Dimension vstrut10 = new Dimension(1, 10);
 
-    private static final Insets insets = new Insets(10, 10, 10, 10);
-
     private static Dimension prefListSize = new Dimension(75, 150);
 
     private static Dimension PREF_SIZE = new Dimension(435, 360);
     private static Dimension MIN_SIZE = new Dimension(200, 300);
 
-    private static Dimension PREF_ACC_SIZE = new Dimension(10, 10);
     private static Dimension ZERO_ACC_SIZE = new Dimension(1, 1);
 
     private static Dimension MAX_SIZE = new Dimension(Short.MAX_VALUE, Short.MAX_VALUE);
@@ -125,7 +122,6 @@ class GTKFileChooserUI extends SynthFileChooserUI {
     private JPanel bottomButtonPanel;
     private GTKDirectoryModel model = null;
     private Action newFolderAction;
-    private JPanel interior;
     private boolean readOnly;
     private boolean showDirectoryIcons;
     private boolean showFileIcons;
@@ -710,15 +706,19 @@ class GTKFileChooserUI extends SynthFileChooserUI {
         bottomButtonPanel.setName("GTKFileChooser.bottomButtonPanel");
         align(bottomButtonPanel);
 
+        JPanel pnButtons = new JPanel(new GridLayout(1, 2, 5, 0));
+
         JButton cancelButton = getCancelButton(fc);
         align(cancelButton);
         cancelButton.setMargin(buttonMargin);
-        bottomButtonPanel.add(cancelButton);
+        pnButtons.add(cancelButton);
 
-        JButton approveButton = getApproveButton(fc);;
+        JButton approveButton = getApproveButton(fc);
         align(approveButton);
         approveButton.setMargin(buttonMargin);
-        bottomButtonPanel.add(approveButton);
+        pnButtons.add(approveButton);
+
+        bottomButtonPanel.add(pnButtons);
 
         if (fc.getControlButtonsAreShown()) {
             fc.add(bottomButtonPanel, BorderLayout.SOUTH);
@@ -1108,7 +1108,7 @@ class GTKFileChooserUI extends SynthFileChooserUI {
             // Get the canonical (full) path. This has the side
             // benefit of removing extraneous chars from the path,
             // for example /foo/bar/ becomes /foo/bar
-            File canonical = null;
+            File canonical;
             try {
                 canonical = fsv.createFileObject(ShellFolder.getNormalizedFile(directory).getPath());
             } catch (IOException e) {
diff --git a/src/share/classes/javax/swing/MenuSelectionManager.java b/src/share/classes/javax/swing/MenuSelectionManager.java
index 1070f35983c20a7f7596f47f4d81e084040dc5dd..aec83c9ab193302929d8fad9984ed151a5f375b8 100644
--- a/src/share/classes/javax/swing/MenuSelectionManager.java
+++ b/src/share/classes/javax/swing/MenuSelectionManager.java
@@ -218,9 +218,9 @@ public class MenuSelectionManager {
         int selectionSize;
         p = event.getPoint();
 
-        Component source = (Component)event.getSource();
+        Component source = event.getComponent();
 
-        if (!source.isShowing()) {
+        if ((source != null) && !source.isShowing()) {
             // This can happen if a mouseReleased removes the
             // containing component -- bug 4146684
             return;
@@ -236,7 +236,9 @@ public class MenuSelectionManager {
             return;
         }
 
-        SwingUtilities.convertPointToScreen(p,source);
+        if (source != null) {
+            SwingUtilities.convertPointToScreen(p, source);
+        }
 
         screenX = p.x;
         screenY = p.y;
diff --git a/test/javax/swing/JPopupMenu/6690791/bug6690791.java b/test/javax/swing/JPopupMenu/6690791/bug6690791.java
new file mode 100644
index 0000000000000000000000000000000000000000..bfbf3c39e4ea75d8b33876efb2489fac743c7b7f
--- /dev/null
+++ b/test/javax/swing/JPopupMenu/6690791/bug6690791.java
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2008 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 6690791
+ * @summary Checks that there is no ClassCastException
+ * in MenuSelectionManager.processMouseEvent()
+ * @author Mikhail Lapshin
+ * @run main bug6690791
+ */
+
+import javax.swing.*;
+import java.awt.event.MouseEvent;
+
+public class bug6690791 {
+    public static void main(String[] args) throws Exception {
+        MouseEvent me = new MouseEvent(new JLabel(), MouseEvent.MOUSE_CLICKED,
+                System.currentTimeMillis(), MouseEvent.ALT_MASK,
+                10, 10, 100, 100, 1, false, MouseEvent.BUTTON1);
+        me.setSource(new Object());
+        MenuSelectionManager.defaultManager().processMouseEvent(me);
+    }
+}