mport java.awt.BorderLayout;
import java.awt.event.ActionEvent;

import javax.swing.AbstractAction;
Reporter of JDK-8174845 verified the bug and reported the following issue:

The problem is only partially solved. A toolbar button with an ImageIcon is
wrong scaled.

We use the follow simple test program (binary attached). Currently we see no
option to prevent this. Is there a new API?

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JToolBar;

public class Main {
    public static void main(String[] args) {
    
        JToolBar toolbar = new JToolBar();
        
        toolbar.add( new JButton(new AbstractAction( "", new
ImageIcon(Main.class.getResource("icon.gif")) ) {
            @Override
            public void actionPerformed(ActionEvent e) {
            }
        }) );
        toolbar.add( new JButton(new AbstractAction( "", new
ImageIcon(Main.class.getResource("icon2.gif")) ) {
            @Override
            public void actionPerformed(ActionEvent e) {
            }
        }) );
        toolbar.add( new JButton(new AbstractAction( "", new
ImageIcon(Main.class.getResource("icon3.gif")) ) {
            @Override
            public void actionPerformed(ActionEvent e) {
            }
        }) );
        
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(toolbar, BorderLayout.NORTH);
        frame.setSize(800, 600);
        frame.setVisible(true);