Name: rmT116609 Date: 11/04/2002


FULL PRODUCT VERSION :
java version "1.4.1"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1-b21)
Java HotSpot(TM) Client VM (build 1.4.1-b21, mixed mode)

FULL OPERATING SYSTEM VERSION :
Windows NT Version 4.0

A DESCRIPTION OF THE PROBLEM :
If a DesktopManager is set in JDesktopPane.setDesktopManager() or returned in a subclass by JDesktopPane.getDesktopManager(), BasicDesktopPaneUI.desktopManager will be set to null after a JDesktopPane.updateUI(). This will cause a crash
on a keyboard internal frame switch (Ctrl-F6).

 From the code, it seems like BasicDesktopPaneUI.installDesktopManager() needs to set desktopManager, but there may be some reason that this was not done.

       protected void installDesktopManager() {
         if(desktop.getDesktopManager() == null) {
            desktopManager = new DefaultDesktopManager();
            desktop.setDesktopManager(desktopManager);
         }
         // Possibly need to add this.
         else
            desktopManager = desktop.getDesktopManager();
      }


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Compile and run code.
2. Select internal frame.
3. Hit Ctrl-F6.

EXPECTED VERSUS ACTUAL BEHAVIOR :
Expect nothing, get a stack dump.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
java.lang.NullPointerException
     at
javax.swing.plaf.basic.BasicDesktopPaneUI$NavigateAction.actionPerformed
(BasicDesktopPaneUI.java:442)
     at javax.swing.SwingUtilities.notifyAction(SwingUtilities.java:1512)
     at javax.swing.JComponent.processKeyBinding(JComponent.java:2435)
     at javax.swing.JComponent.processKeyBindings(JComponent.java:2481)
     at javax.swing.JComponent.processKeyEvent(JComponent.java:2398)
     at java.awt.Component.processEvent(Component.java:4902)
     at java.awt.Container.processEvent(Container.java:1566)
     at java.awt.Component.dispatchEventImpl(Component.java:3598)
     at java.awt.Container.dispatchEventImpl(Container.java:1623)
     at java.awt.Component.dispatchEvent(Component.java:3439)
     at java.awt.KeyboardFocusManager.redispatchEvent
(KeyboardFocusManager.java:1688)
     at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent
(DefaultKeyboardFocusManager.java:593)
     at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent
(DefaultKeyboardFocusManager.java:765)
     at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions
(DefaultKeyboardFocusManager.java:698)
     at java.awt.DefaultKeyboardFocusManager.dispatchEvent
(DefaultKeyboardFocusManager.java:559)
     at java.awt.Component.dispatchEventImpl(Component.java:3468)
     at java.awt.Container.dispatchEventImpl(Container.java:1623)
     at java.awt.Window.dispatchEventImpl(Window.java:1585)
     at java.awt.Component.dispatchEvent(Component.java:3439)
     at java.awt.EventQueue.dispatchEvent(EventQueue.java:450)
     at java.awt.EventDispatchThread.pumpOneEventForHierarchy
(EventDispatchThread.java:197)
     at java.awt.EventDispatchThread.pumpEventsForHierarchy
(EventDispatchThread.java:150)
     at java.awt.EventDispatchThread.pumpEvents
(EventDispatchThread.java:144)
     at java.awt.EventDispatchThread.pumpEvents
(EventDispatchThread.java:136)
     at java.awt.EventDispatchThread.run(EventDispatchThread.java:99)
    


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import javax.swing.*;

    public class JDesktopPaneBug extends JFrame {
   
       public static void main(String[] args) {
         (new JDesktopPaneBug()).setVisible(true);
      }
   
       public JDesktopPaneBug() {
         setSize(400, 400);
         JDesktopPane dtp = new JDesktopPane();
         dtp.setDesktopManager(new DefaultDesktopManager());
         JInternalFrame jif = new JInternalFrame("A", true, false, true, true);
         jif.setSize(200, 200);
         jif.setVisible(true);
         dtp.add(jif);
         getContentPane().add(dtp);
      
         dtp.updateUI();
      }
   }

---------- END SOURCE ----------
(Review ID: 166602)
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