dependent window won't close, causing hang

   a dependent window does not close and causes the entire application to
   hang, when the "hide" method is called.

   reproduce the error with the supplied code:

 run the Hugh program, press Help - About.
   when pressing the "OK" button in the dependent window, any further
   action fails.

   the application works correctly with Win95 x86, with jdk 1.0.2.


>From: ###@###.### ( Andreas Froehlich (J. Zedler))
// source code for file Hugh.java follows
//
// presumed position where bug occurs is marked as follows:
// SITE OF BUG
//

import java.awt.*;

public class Hugh extends Frame {

    Panel guiPanel,
          buttonPanel;

    Choice paraFormat;

    Button boldBtn,
           italBtn;

    TextArea textArea;

    Menu menuFile,
         menuEdit,
         menuFormat,
         menuHelp;

    MenuItem itemOpen,
             itemSaveAs,
             itemExit,
             itemAbout;

    public Hugh() {

        super("Hugh ");

        MenuBar menuBar;
        Menu menu;


     menuBar = new MenuBar();

        menuFile = new Menu("&File");
        menuFile.add(new MenuItem("&New"));
        menuFile.add(itemOpen = new MenuItem("&Open..."));
        menuFile.add(new MenuItem("&Save"));
        menuFile.add(itemSaveAs = new MenuItem("Save &As..."));
        menuFile.addSeparator();
        menuFile.add(itemExit = new MenuItem("E&xit"));
        menuBar.add(menuFile);

        menuEdit = new Menu("&Edit");
        menuEdit.add(new MenuItem("&Undo"));
        menuEdit.addSeparator();
        menuEdit.add(new MenuItem("Cu&t"));
        menuEdit.add(new MenuItem("&Copy"));
        menuEdit.add(new MenuItem("&Paste"));
        menuBar.add(menuEdit);

        menuFormat = new Menu("F&ormat");
        menuFormat.add(new MenuItem("&Font"));
        menuFormat.add(new MenuItem("&Paragraph"));
        menuBar.add(menuFormat);

        menuHelp = new Menu("&Help");
        menuHelp.add(itemAbout = new MenuItem("&About..."));
        menuBar.add(menuHelp);

        setLayout(new BorderLayout());

        guiPanel = new Panel();
        guiPanel.setLayout(new BorderLayout());


        buttonPanel = new Panel();
        GridBagLayout gbl = new GridBagLayout();
        GridBagConstraints c = new GridBagConstraints();


        buttonPanel.setLayout(new GridBagLayout());

        setLayout(gbl);

        c.fill = GridBagConstraints.BOTH;
        c.weightx = 1.0;

        paraFormat = new Choice();
          paraFormat.addItem("Headline");
          paraFormat.addItem("Sub-Headline");
          paraFormat.addItem("numbered");
          paraFormat.addItem("bulleted");
        paraFormat.addItem("regular");
        gbl.setConstraints(paraFormat, c);
        add(paraFormat);

        italBtn = new Button ("Italic");
        gbl.setConstraints(italBtn, c);
        add(italBtn);


        boldBtn = new Button ("Bold");
        c.gridwidth = GridBagConstraints.REMAINDER;
        gbl.setConstraints(boldBtn, c);
        add(boldBtn);

        textArea = new TextArea();

        c.weightx = 0.0;
        c.fill = GridBagConstraints.VERTICAL;
        c.gridwidth = GridBagConstraints.REMAINDER;
        gbl.setConstraints(textArea, c);
        add(textArea);

        setMenuBar(menuBar);

        move(200,200);
        resize(400,300);

     show();
    } // public hugh

    public boolean action(Event event, Object arg)
    {
     if (event.target instanceof MenuItem) {
     MenuItem menuItem = (MenuItem)event.target;
     Menu menuParent = (Menu)(menuItem.getParent());

     if (menuParent == menuFile) {
if (menuItem == itemOpen)
(new FileDialog(this, "Open...")).show();

                else if (menuItem == itemSaveAs)
                    (new FileDialog(this, "Save As...")).show();

     else if (menuItem == itemExit)
(new QuitDialog(this)).show();

     } else if (menuParent == menuHelp) {
if (menuItem == itemAbout)
     (new AboutDialog(this)).show();
     }
    }

        return true;
    }

    public boolean handleEvent(Event event) {
     if (event.id == Event.WINDOW_DESTROY)
     {
      //(new QuitDialog(this)).show();
     System.out.println("Hugh:Window_destroy");
     System.exit(0);
     }

     return super.handleEvent(event);
    }

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

// import java.awt.*;

//
// In dieser Klasse AboutDialog
// steckt der ?Fehler?
// m.e. in der handleEvent - methode
//


class AboutDialog extends Dialog {

    public AboutDialog(Frame parent) {
super(parent, "About", true);

setLayout(new FlowLayout());

        add("Center", new Label("Hugh "
                              , Label.CENTER));
     add("South", new Button("OK"));

     reshape(30, 30, 200, 90);

     setResizable(false);
    }

    public synchronized void show() {
     Rectangle bounds = getParent().bounds();
     Rectangle abounds = bounds();

     move(bounds.x + (bounds.width - abounds.width)/ 2,
     bounds.y + (bounds.height - abounds.height)/2);

     super.show();
    }

    public synchronized void wakeUp() {
     notify();
    }

    public boolean handleEvent(Event e) {
     if (e.id == Event.WINDOW_DESTROY) {

// SITE OF BUG

     hide(); // SITE OF BUG

// SITE OF BUG

     return true;
     } else
     return super.handleEvent(e);
    }

    public boolean action(Event e, Object arg) {
     if (((String)arg).equals("OK"))
     hide();

     return true;
    }
} //class AboutDialog


class QuitDialog extends Dialog {

    public QuitDialog(Frame parent) {
     super(parent, "Quit Application?", true);
     setLayout(new FlowLayout());

     add(new Button("Yes"));
     add(new Button("No"));

     reshape(30, 30, 200, 60);

     setResizable(false);
    }

    public synchronized void show() {
     Rectangle bounds = getParent().bounds();
     Rectangle abounds = bounds();

     move(bounds.x + (bounds.width - abounds.width)/ 2,
            bounds.y + (bounds.height - abounds.height)/2);

     super.show();
    }

    public synchronized void wakeUp() {
     notify();
    }

    public boolean handleEvent(Event e) {
if (e.id == Event.WINDOW_DESTROY) {
hide();

return true;

} else
return super.handleEvent(e);
    }

/*
    public boolean handleEvent(Event e) {
if (e.id == Event.WINDOW_DESTROY)
{
hide();
System.out.println("Hide");

// return true;
return super.handleEvent(e);
}
else
{
System.out.println("super.handleEvent");
return super.handleEvent(e);
}
    }
*/

    public boolean action(Event e, Object arg) {
     String label = (String)arg;

     if (label.equals("Yes"))
     System.exit(0);

     else if (label.equals("No"))
     hide();

     return true;
    }
} // class QuitDialog

// end of source code Hugh.java



class QuitDialog extends Dialog {

    public QuitDialog(Frame parent) {
     super(parent, "Quit Application?", true);
     setLayout(new FlowLayout());

     add(new Button("Yes"));
     add(new Button("No"));

     reshape(30, 30, 200, 60);

     setResizable(false);
    }

    public synchronized void show() {
     Rectangle bounds = getParent().bounds();
     Rectangle abounds = bounds();

     move(bounds.x + (bounds.width - abounds.width)/ 2,
            bounds.y + (bounds.height - abounds.height)/2);

     super.show();
    }

   public synchronized void wakeUp() {
     notify();
    }

    public boolean handleEvent(Event e) {
if (e.id == Event.WINDOW_DESTROY) {
hide();

return true;

} else
return super.handleEvent(e);
    }

/*
    public boolean handleEvent(Event e) {
if (e.id == Event.WINDOW_DESTROY)
{
hide();
System.out.println("Hide");

// return true;
return super.handleEvent(e);
}
else
{
System.out.println("super.handleEvent");
return super.handleEvent(e);
}
    }
*/

    public boolean action(Event e, Object arg) {
     String label = (String)arg;

     if (label.equals("Yes"))
     System.exit(0);

     else if (label.equals("No"))
     hide();

     return true;
    }
} // class QuitDialog