Reported on the OpenJDK 2d-dev list :
In trying to render a table of characters using their Unicode
identifiers, I found that the character \u0DDD crashes my JVM as soon
as it is rendered to a Swing component. I'm not particularly
interested in that character--I am just trying to print out different
characters in different fonts to easily track which glyphs are
available per font. I found this by accident. I'm writing to this list
as I suspect (but don't know) that it may be an issue with the font
system.

java -version
java version "1.6.0_10"
Java(TM) SE Runtime Environment (build 1.6.0_10-b33)
Java HotSpot(TM) Client VM (build 11.0-b15, mixed mode, sharing)

Ubuntu 8.10
uname -r
2.6.27-7-generic

Small app that shows the problem:
import javax.swing.*;
import javax.swing.border.LineBorder;
import java.awt.*;
import java.awt.event.ActionEvent;

public class TestChar {
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new TestChar().run();
            }
        });
    }

    private void run() {
        JFrame frame = new JFrame("Test Character");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        JPanel panel = new JPanel();
        final JLabel label = new JLabel("(empty)");
        label.setSize(400, 100);
        label.setBorder(new LineBorder(Color.black));
        JButton button = new JButton("Set Char x0DDD");
        button.addActionListener(new AbstractAction() {
            public void actionPerformed(ActionEvent actionEvent) {
                label.setText(Character.toString('\u0DDD'));
            }
        });
        panel.add(button);
        panel.add(label);

        frame.getContentPane().add(panel);
        frame.pack();
        frame.setVisible(true);
    }
}

Run this, then click the button. On my Ubuntu system, clicking the
button causes an immediate crash of the VM. Have also tested on OS X
java -version
java version "1.6.0_07"
Java(TM) SE Runtime Environment (build 1.6.0_07-b06-153)
Java HotSpot(TM) 64-Bit Server VM (build 1.6.0_07-b06-57, mixed mode)

and the VM _did not crash_.

Output in the Ubuntu console following the crash is attached.



$ java -cp out/production/Samples TestChar &>out.txt
*** glibc detected *** java: free(): invalid next size (fast): 0x09db39d0 ***
======= Backtrace: =========
/lib/tls/i686/cmov/libc.so.6[0xb7f833f4]
/lib/tls/i686/cmov/libc.so.6(cfree+0x96)[0xb7f85456]
/usr/java/jdk1.6.0_10/jre/lib/i386/libfontmanager.so[0xb55c92cc]
/usr/java/jdk1.6.0_10/jre/lib/i386/libfontmanager.so[0xb55d0b22]
/usr/java/jdk1.6.0_10/jre/lib/i386/libfontmanager.so[0xb55d1e4d]
/usr/java/jdk1.6.0_10/jre/lib/i386/libfontmanager.so[0xb55cf90d]
/usr/java/jdk1.6.0_10/jre/lib/i386/libfontmanager.so(Java_sun_font_SunLayoutEngine_nativeLayout+0x24f)[0xb55d193f]