Name: bsC130419 Date: 06/06/2001


java version "1.4.0-beta"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-beta-b65)
Java HotSpot(TM) Client VM (build 1.4.0-beta-b65, mixed mode)

class: java.awt.CardLayout
method: public void show(Container parent, String name)

API tells that if the component to show doesn't exists, nothing happens. This
is the case in jdk1.3.

In 1.4, a NullPointerException occurs because the code doesn't check for a null
result in this line (CardLayout.java, line 449):

            if (((Card) vector.get(currentCard)).name.equals(name))

The code should check that vector.get(currentCard) doesn't return null.

It was the case in 1.3:
            if ((next != null) && !next.visible){ ... }


Here is small application to reproduce the problem. It works fine in 1.3 but
generates an exception in 1.4 :

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

public class Test extends JFrame {
        public Test() {
                CardLayout layout = new CardLayout();
                getContentPane().setLayout(layout);
                layout.show(getContentPane(), "panel");
        }

        public static void main(String[] s){
                (new Test()).show();
        }
}


(Review ID: 125931)
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