FULL PRODUCT VERSION :
java version "1.5.0_04"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_04-b05)
Java HotSpot(TM) Client VM (build 1.5.0_04-b05, mixed mode, sharing)

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

A DESCRIPTION OF THE PROBLEM :
If I create a custom FocusTraversalPolicy and set it on a container that is the FocusCycleRoot (Window, Dialog, etc.) and add a JTable as a child of the container, as soon as I edit the first cell, my custom FocusTraversalPolicy is overwritten by LegacyGlueFocusTraversalPolicy. It doesn't matter if it is a custom FTP or the default - it will be replaced.

Related to LegacyGlueFocusTraversalPolicy.
Could not find any existing, reported bugs with the same description.
Exists in all JDK versions since 1.4 (LegacyGlueFocusTraversalPolicy).

Cause:
JTable.prepareEditor() calls jComp.setNextFocusableComponent(this).
JTable.editCellAt() calls add(editorComp) which eventually calls JComponent.registerNextFocusableComponent(comp).
This method ALWAYS replaces the nearest focusCycleRoot's FTP with LegacyGlueFocusTraversalPolicy when a next focusable component exists.

I didn't check JTree or any other containers to see if they do the same thing.


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Create a custom FocusTraversalPolicy and set it on a JFrame or JDialog. Add an editable JTable to it. Run the app. Edit a cell in the JTable. The FocusTraversalPolicy you originally added is now replaced by LegacyGlueFocusTraversalPolicy.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
I would expect the original FocusTraversalPolicy to remain and not be replaced by LegacyGlueFocusTraversalPolicy for any reason.
ACTUAL -
As soon as I edit a cell in a JTable the parent container's FocusTraversalPolicy is replaced by LegacyGlueFocusTraversalPolicy and all of the behavior and state of the previous policy is lost.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
Original FocusTraversalPolicy: javax.swing.LayoutFocusTraversalPolicy@105738

Forced exception call stack when the FTP is replaced:

java.lang.Exception
at test.FocusTraversalPolicyTest$1.propertyChange(FocusTraversalPolicyTest.java:40)
at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:330)
at java.beans.PropertyChangeSupport.firePropertyChange(PropertyChangeSupport.java:257)
at java.awt.Component.firePropertyChange(Component.java:6695)
at java.awt.Container.setFocusTraversalPolicy(Container.java:2525)
at javax.swing.JComponent.registerNextFocusableComponent(JComponent.java:982)
at javax.swing.JComponent.registerNextFocusableComponent(JComponent.java:968)
at javax.swing.JComponent.addNotify(JComponent.java:4292)
at java.awt.Container.addImpl(Container.java:658)
at java.awt.Container.add(Container.java:307)
at javax.swing.JTable.editCellAt(JTable.java:2537)
at javax.swing.plaf.basic.BasicTableUI$MouseInputHandler.adjustFocusAndSelection(BasicTableUI.java:510)
at javax.swing.plaf.basic.BasicTableUI$MouseInputHandler.mousePressed(BasicTableUI.java:494)
at java.awt.AWTEventMulticaster.mousePressed(AWTEventMulticaster.java:222)
at java.awt.Component.processMouseEvent(Component.java:5097)
at java.awt.Component.processEvent(Component.java:4897)
at java.awt.Container.processEvent(Container.java:1569)
at java.awt.Component.dispatchEventImpl(Component.java:3615)
at java.awt.Container.dispatchEventImpl(Container.java:1627)
at java.awt.Component.dispatchEvent(Component.java:3477)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:3483)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3195)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3128)
at java.awt.Container.dispatchEventImpl(Container.java:1613)
at java.awt.Window.dispatchEventImpl(Window.java:1606)
at java.awt.Component.dispatchEvent(Component.java:3477)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:456)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:145)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:137)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:100)

FocusTraversalPolicy after editing a cell in a JTable: javax.swing.LegacyGlueFocusTraversalPolicy@9f5011

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
public class FocusTraversalPolicyTest extends JFrame
{
public FocusTraversalPolicyTest()
{
setTitle("Focus Traversal Policy Test");

Container p = getContentPane();
p.setLayout(new BorderLayout());

// Edit a cell in the table when you run the program
JTable table = new JTable(5,5);
p.add(table);

System.out.println("Original FocusTraversalPolicy: "+FocusTraversalPolicyTest.this.getFocusTraversalPolicy());
addPropertyChangeListener("focusTraversalPolicy", new PropertyChangeListener()
{
public void propertyChange(PropertyChangeEvent evt)
{
new Exception().printStackTrace();
System.out.println("FocusTraversalPolicy after editing a cell in a JTable: "+FocusTraversalPolicyTest.this.getFocusTraversalPolicy());
}
});
}


public static void main(String[] args)
{
FocusTraversalPolicyTest test = new FocusTraversalPolicyTest();

test.setSize(500,500);
test.setLocation(100,100);
test.setVisible(true);
}
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
I have written a temporary fix by overriding a method in JTable but I don't want to include it here because it is not something I want to have to maintain in my code into the future. It also prevents me from using JTable directly - I have to extend it.