FULL PRODUCT VERSION :
java version "1.7.0_11"
Java(TM) SE Runtime Environment (build 1.7.0_11-b21)
Java HotSpot(TM) 64-Bit Server VM (build 23.6-b04, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.1.7601]

A DESCRIPTION OF THE PROBLEM :
Press the button to open the dialog at least once.
When the main window is then closed, the "windowClosed fired" related to the dialog re-appears, and the JVM never completes.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
See executable test case.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
JVM terminates. Dialog closing action is not fired by the main window closing.
ACTUAL -
JVM does not terminate. Dialog closing action fires when the main window closes.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;
import java.awt.Dialog;
import java.awt.event.ActionEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

public class DialogClosingBug implements Runnable
{
    public static void main(String[] args)
    {
        SwingUtilities.invokeLater(new DialogClosingBug());
    }

    @Override
    public void run()
    {
        final JFrame frame = new JFrame("Test");
        frame.add(new JButton(new AbstractAction("Show Dialog")
        {
            @Override
            public void actionPerformed(ActionEvent event)
            {
                showDialog(frame);
            }
        }));
        frame.pack();
        frame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
        frame.setVisible(true);
    }

    private void showDialog(final JFrame frame)
    {
        JDialog dialog = new JDialog(frame, "Dialog", Dialog.ModalityType.DOCUMENT_MODAL);
        dialog.add(new JLabel("Content here"));
        dialog.pack();
        dialog.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
        dialog.addWindowListener(new WindowAdapter()
        {
            @Override
            public void windowClosed(WindowEvent event)
            {
                JOptionPane.showMessageDialog(frame, "windowClosed fired");
            }
        });
        dialog.setVisible(true);
    }
}
---------- END SOURCE ----------