FULL PRODUCT VERSION :
java version "1.6.0_03"
Java(TM) SE Runtime Environment (build 1.6.0_03-b05)
Java HotSpot(TM) Client VM (build 1.6.0_03-b05, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
5.1.2600

A DESCRIPTION OF THE PROBLEM :
If you enter a tab character in a JTextPane then select it and press Enter to delete it the application locks up.

The tab should have some text before it and some text after it.


STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
This test code below shows problem. The same happens with a JTextPane

Run test code
Put cursor on line between ‘1’ and ‘2’
Press Tab
Select Tab
Press Enter
Application locks up with Java 6. Java 5 is ok.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Should be able to continue editing.
ACTUAL -
Application containing JTextPane is frozen.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
public class TabBug extends javax.swing.JDialog
{

  public TabBug(java.awt.Frame parent)
  {
    super(parent, true);
    initComponents();
  }

  private void initComponents()
  {

    javax.swing.JScrollPane jScrollPane1 = new javax.swing.JScrollPane();
    javax.swing.JEditorPane editPane = new javax.swing.JTextPane();

    editPane.setText("1\n\n2");
    jScrollPane1.setViewportView(editPane);

    add(jScrollPane1);


    pack();
  }

  public static void main(String args[])
  {
    TabBug dialog = new TabBug(new javax.swing.JFrame());
    dialog.setVisible(true);
  }
}

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

CUSTOMER SUBMITTED WORKAROUND :
None found so far.

Release Regression From : 5.0u12
The above release value was the last known release where this
bug was not reproducible. Since then there has been a regression.