FULL PRODUCT VERSION :
java version "1.6.0-beta2"
Java(TM) SE Runtime Environment (build 1.6.0-beta2-b75)
Java HotSpot(TM) Client VM (build 1.6.0-beta2-b75, mixed mode)
java version "1.5.0_06"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-b05)
Java HotSpot(TM) Client VM (build 1.5.0_06-b05, mixed mode)


ADDITIONAL OS VERSION INFORMATION :
Linux snoopy 2.6.13-suspend2-r5 #2 Wed Feb 1 11:19:24 CET 2006 i686 Intel(R) Pentium(R) M processor 1.70GHz GenuineIntel GNU/Linux
Linux pernille 2.6.12-gentoo-r10 #1 Sat Sep 24 13:28:47 CEST 2005 i686 AMD Athlon(tm) XP 2100+ AuthenticAMD GNU/Linux

EXTRA RELEVANT SYSTEM CONFIGURATION :
Both computers use KDE 3.5.1.
One has ATI graphics, using default radeon driver from xorg 6.8.2, the other has Nvidia graphics using official drivers version 6629.

A DESCRIPTION OF THE PROBLEM :
The problem is when appending text to a JTextArea or JTextPane in a JFrame which is hidden with setVisible(false). When the JFrame is setVisible(true) again, only some or nothing of the new text is visible, if the JFrame is opening on top of another window. Selecting the text fixes the problem. If there are no windows behind the JFrame which is setVisible(true), then the text is normal.

This is just in the mustang build. I noticed the problem when I tested with a chat program which can be minimized to the systray.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Make sure to run Mustang (tested only with b75).
2. Compile and run the included app.
3. Place some other window behind the app, so it would cover part of the JTextArea if it was in front.
4. Press the hide button.
5. Wait until the app reappears.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The text in the JTextArea should look normal.
ACTUAL -
The text which was on the spot where the other window was, is not showing. The text which was not covered by the other window looks normal. If the other window covers the java app completely, then everything looks okey.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class TextVisibilityBugTester extends JFrame
{
private Container cont;
private JTextArea txtTA;
private JScrollPane txtS;
private JButton hideB;

public TextVisibilityBugTester()
{
txtTA = new JTextArea();
txtS = new JScrollPane( txtTA );
hideB = new JButton( "Hide 1 sec" );

hideB.addActionListener( new ActionListener()
{
public void actionPerformed( ActionEvent e )
{
setVisible( false );

txtTA.append( "adding some new long text to the\n" );
txtTA.append( "text area to see what happens...\n" );
txtTA.append( "adding some new long text to the\n" );
txtTA.append( "text area to see what happens...\n" );

new Thread()
{
public void run()
{
try
{
Thread.sleep( 1000 );
setVisible( true );
}

catch ( InterruptedException e ) {}
}
}.start();
}
} );

cont = getContentPane();
cont.add( txtS, BorderLayout.CENTER );
cont.add( hideB, BorderLayout.SOUTH );

setSize( 250, 300 );
setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
setTitle( "TextVisibilityBugTester" );
setVisible( true );
}

public static void main( String[] args )
{
new TextVisibilityBugTester();
}
}

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