FULL PRODUCT VERSION :
java version "1.5.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0-b64)
Java HotSpot(TM) Client VM (build 1.5.0-b64, mixed mode, sharing)


ADDITIONAL OS VERSION INFORMATION :
Linux btu5h 2.4.20-31.9 #1 Tue Apr 13 17:38:16 EDT 2004 i686 athlon i386 GNU/Linux


A DESCRIPTION OF THE PROBLEM :
When I use Toolkit.getDefaultToolkit().getSystemClipboard().addFlavorListener
I will get a stack trace whenever I do a Drag and Drop operation that involves a move. This is true of *any* component using TransferHandler.

If I do not have Toolkit.getDefaultToolkit().getSystemClipboard().addFlavorListener in
my program, all works just fine.


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run the sample program I give later in this report.
Attempt to drag and drop between the two text fields.


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Drag and Drop works fine.

ACTUAL -
Strack trace (although Dnd seems to have worked)


ERROR MESSAGES/STACK TRACES THAT OCCUR :
Exception on Toolkit thread: java.lang.NullPointerException
java.lang.NullPointerException
        at sun.awt.X11.XSelection.checkChange(XSelection.java:701)
        at sun.awt.X11.XSelection.access$200(XSelection.java:28)
        at sun.awt.X11.XSelection$SelectionEventHandler.dispatchEvent(XSelection.java:710)
        at sun.awt.X11.XToolkit.dispatchEvent(XToolkit.java:408)
        at sun.awt.X11.XToolkit.run(XToolkit.java:493)
        at sun.awt.X11.XToolkit.run(XToolkit.java:438)
        at java.lang.Thread.run(Thread.java:595)


REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import javax.swing.* ;
import java.awt.* ;
import java.awt.datatransfer.* ;
                                                                                                                        
public class test extends JFrame {
        public test() {
                getContentPane().setLayout(new FlowLayout()) ;
                JTextField jt1 = new JTextField("abc",20) ;
                jt1.setDragEnabled(true) ;
                JTextField jt2 = new JTextField("def",20) ;
                jt2.setDragEnabled(true) ;
                add(jt1) ;
                add(jt2) ;
        }
                                                                                                                        
    public static void main(String args[]) {
        Toolkit.getDefaultToolkit().getSystemClipboard().addFlavorListener(new FlavorListener() {
            public void flavorsChanged(FlavorEvent e) {
            }
        }) ;
        test t = new test() ;
        t.pack() ;
        t.setVisible(true) ;
    }
}

---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Don't use Toolkit.getDefaultToolkit().getSystemClipboard().addFlavorListener
###@###.### 10/21/04 22:07 GMT