JListBox.getSelectedIndices() does not work correctly

To reproduce the problem, compile and run the following code.

import java.awt.*;
import java.awt.event.*;
import com.sun.java.swing.*;

public class listbox2
{
    public static void main(String[] args)
        {
            String strings[] = { "zero", "one", "two", "three", "four" };
            final JListBox listbox = new JListBox( strings );
            JPanel p = new JPanel();
            p.setLayout(new GridLayout(1,1));
            p.add(listbox);

            listbox.addSelectionInterval(0,3);
            int ids[] = listbox.getSelectedIndices();
            System.out.println( "Number of selected indices = " + ids.length +
                                " (should be 4)" );
            System.out.println( "Selected indices:" );
            for( int i=0; i<ids.length; i++ )
                System.out.println( " " + ids[i] );

            WindowListener l = new WindowAdapter() {
                public void windowClosing(WindowEvent e) {System.exit(0);}
            };

            JFrame f = new JFrame("ListBox");
            f.addWindowListener(l);
            f.add(p);
            f.pack();
            f.show();
        }
}