OPERATING SYSTEM(S):
--------------------
Windows Vista (Japanese)

FULL JDK VERSION(S):
-------------------
java version "1.6.0_01"
Java(TM) SE Runtime Environment (build 1.6.0_01-b05)
Java HotSpot(TM) Client VM (build 1.6.0_01-b05, mixed mode)

DESCRIPTION:
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If Unicode Extension B character is input in JTextArea, character decoration such as underline or reversed doesn't appear.

The problem doesn't occur with only BMP characters.

Recreate steps:
1. Install Windows Vista with Japanese support.
2. Compile and launch the sample code.
3. Turn on MS-IME.
4. Input some Japanese characters.
=> Input characters by MS-IME have underline or reversed decoration.
   However, the decoration does not appear.

If the problem doesn't occur, press Enter key. Then repeat step 4.

It's hard to input Japanese characters without underline and reversed.
They indicate conversion target.

-----JTextAreaTest.java---------------------------------
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class JTextAreaTest extends JTextArea {
        public JTextAreaTest() {
                super();
                setText("Unicode Extension B: \ud840\udc0b");
        }
        public static void main(String[] args) {
                JFrame frame = new JFrame("Swing JTextArea component");
                frame.getContentPane().add(new JTextAreaTest());
                frame.addWindowListener(new WindowAdapter() {
                        public void windowClosing(WindowEvent event) {
                                System.exit(0);
                        }
                });
                frame.setSize(300, 300);
                frame.setVisible(true);
        }
}
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