FULL PRODUCT VERSION :
java version "1.6.0-ea"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.6.0-ea-b46)
Java HotSpot(TM) Client VM (build 1.6.0-ea-b46, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]

A DESCRIPTION OF THE PROBLEM :
When a JMenuItem is displayed and the same application (running in the same JVM) has a TrayIcon, errors occur when clicking on the tray icon. A ClassCastException occurs which comes from javax.swing.plaf.basic.BasicLookAndFeel$AWTEventHelper.eventDispatched. This class seems to run through all mouse events in the AWT in order to process menu popups.

My guess to the cause of the problem is line 2086 in AWTEventHelper.eventDispatched(). The code is attempting to cast the source of a mouse event into a java.awt.Component, assuming that all sources of mouse events are Components. While this might have been true for JDK 1.5 and earlier, in JDK 1.6 TrayIcons can also generate mouse events and they are NOT subclasses of java.awt.Component.

An instanceof check in AWTEventHelper.eventDispatched() should fix this bug.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run the code in the test case specified. The stack trace occurs when clicking on the tray icon.


ERROR MESSAGES/STACK TRACES THAT OCCUR :
Exception occurred during event dispatching:
java.lang.ClassCastException: java.awt.TrayIcon cannot be cast to java.awt.Component
at javax.swing.plaf.basic.BasicLookAndFeel$AWTEventHelper.eventDispatched(BasicLookAndFeel.java:2086)
at java.awt.Toolkit$SelectiveAWTEventListener.eventDispatched(Toolkit.java:2274)
at java.awt.Toolkit.notifyAWTEventListeners(Toolkit.java:2126)
at java.awt.TrayIcon.dispatchEvent(TrayIcon.java:605)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:597)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:270)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:198)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:171)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:166)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:158)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:119)


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
public class TestMenuAndTray
{
    public static void main(String[] args)
    {
        JFrame pFrame = new JFrame("Good Morning");
        JMenuBar myBar = new JMenuBar();
        JMenu myMenu = new JMenu("File");
        myBar.add(myMenu);
        JMenuItem open = new JMenuItem("Open...");
        myMenu.add(open);
        pFrame.setJMenuBar(myBar);
        pFrame.pack();
        pFrame.setVisible(true);

        SystemTray tray = SystemTray.getSystemTray();
        Image image = Toolkit.getDefaultToolkit().getImage("appicon.jpg");
        TrayIcon myIcon = new TrayIcon(image);
        tray.add(myIcon);
    }
}
---------- END SOURCE ----------