FULL PRODUCT VERSION :
java version "1.8.0-ea"
Java(TM) SE Runtime Environment (build 1.8.0-ea-b117)
Java HotSpot(TM) 64-Bit Server VM (build 25.0-b59, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Darwin mankell 13.0.2 Darwin Kernel Version 13.0.2: Sun Sep 29 19:38:57 PDT 2013; root:xnu-2422.75.4~1/RELEASE_X86_64 x86_64

This is OS X 10.9.1, Mavericks

A DESCRIPTION OF THE PROBLEM :
Popup menus of native apps on OS X have rounded corners.
Contrary to this behavior, Java Swing apps currently have rectangular corners.

It seems like this has worked properly in earlier versions. See https://developer.apple.com/library/mac/releasenotes/CrossPlatform/JavaSnowLeopardUpdate1LeopardUpdate6RN/NewandNoteworthy/NewandNoteworthy.html



ADDITIONAL REGRESSION INFORMATION:
Please see

https://developer.apple.com/library/mac/releasenotes/CrossPlatform/JavaSnowLeopardUpdate1LeopardUpdate6RN/NewandNoteworthy/NewandNoteworthy.html

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Create a JPopupMenu and add it to a component via setComponentPopupMenu(menu).
Open the popup menu with a right-click.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The appearing popup menu should have rounded corners.
ACTUAL -
The popup menu has rectangular corners.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import javax.swing.*;

public class Popup {


    public static void main(String[] args) {
        final JFrame frame = new JFrame();
        final JLabel label = new JLabel("Label");
        final JPopupMenu popup = new JPopupMenu();
        popup.add(new JMenuItem("Item"));
        label.setComponentPopupMenu(popup);
        frame.add(label);
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                frame.setBounds(100, 100, 100, 100);
                frame.setVisible(true);
            }
        });
    }
}

---------- END SOURCE ----------