FULL PRODUCT VERSION :
Java(TM) SE Runtime Environment (build 1.6.0_01-b06)
Java(TM) SE Runtime Environment (build 1.7.0-ea-b13)
Java(TM) SE Runtime Environment (build 1.6.0_02-ea-b02)




ADDITIONAL OS VERSION INFORMATION :
The issue occurs on:
- Debian Etch/Lenny
- Ubuntu Edgy/Feisty

A DESCRIPTION OF THE PROBLEM :
On linux, when a set the gtk and feel; if I add a JButton to a JToolbar and I call button.setVisible(false), then the space taken by the button is not released in the toolbar.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
import java.awt.Dimension;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JToolBar;
import javax.swing.UIManager;
 
 
public class PanelTest extends JFrame
{
public static void main(String[] args)
{
try { UIManager.setLookAndFeel("com.sun.java.swing.plaf.gtk.GTKLookAndFeel"); } catch (Exception e) { /* */ }

PanelTest pt = new PanelTest();
pt.setVisible(true);
}


public PanelTest()
{
JToolBar p = new JToolBar();
JButton b1 = new JButton("test1");
JButton b2 = new JButton("test2");
JButton b3 = new JButton("test3");
 
p.add(b1);
p.add(b2);
p.add(b3);

b2.setVisible(false);
 
getContentPane().add(p);
pack();
}
}



EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The space taken by the button "b2" should be release and the position of the two remained buttons should be updated.
ACTUAL -
The space between "b1" and "b3" is not released when the button "b2" is hidden. The position of the two remained buttons is not updated.

REPRODUCIBILITY :
This bug can be reproduced always.