If the default button is set, pressing Enter usually actives it.
However it is activated even when the button is invisible.

Expected: default button shouldn't activate when it is invisible
Actual: it works even when it is invisible

Step to reproduce:
- Run the test
- Press Enter
- See the output in the console

import javax.swing.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

public class DefaultButtonTest {

    private static void createGui() {
        final JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
        JButton button = new JButton("Default button");
        button.setDefaultCapable(true);
        button.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                System.out.println("DefaultButtonTest.actionPerformed");
            }
        });

        frame.add(button);
        button.setVisible(false);

        frame.getRootPane().setDefaultButton(button);

        frame.setSize(200, 200);
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) throws Exception {
        SwingUtilities.invokeAndWait(new Runnable() {
            public void run() {
                DefaultButtonTest.createGui();
            }
        });
    }
}