Setting setWrapStyleWord(true) and then setting setWrapStyleWord(false) and
then setWrapStyleWord(true) again some how unmaps the JTextArea getRowStart. It causes an Exception to be thrown.

Steps to Reproduce bug:
1: Compile and excute code snippet below.
2: Check Word Wrap check box
3: Uncheck Word Wrap check box
4: Check Word Wrap check box
5: Double Click in JTextArea or Click in JTextArea and then press the
End Key on the keyboard.

Error:
Words should wrap and unwrap. Instead they don't wrap and unwrap and
they cause a NullPointerException to be thrown for
  javax.swing.text.Utilities.getRowStart

Exception:

java SetWordWrap
Exception occurred during event dispatching:
java.lang.NullPointerException
at javax.swing.text.Utilities.getRowStart(Compiled Code)
at javax.swing.text.DefaultEditorKit$BeginLineAction.actionPerformed(DefaultEditorKit.java:1724)
at javax.swing.text.DefaultEditorKit$SelectLineAction.actionPerformed(DefaultEditorKit.java:1961)
at javax.swing.text.DefaultCaret.mouseClicked(DefaultCaret.java:298)
at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:211)
at java.awt.AWTEventMulticaster.mouseClicked(AWTEventMulticaster.java:210)
at java.awt.Component.processMouseEvent(Compiled Code)
at java.awt.Component.processEvent(Compiled Code)
at java.awt.Container.processEvent(Compiled Code)
at java.awt.Component.dispatchEventImpl(Compiled Code)
at java.awt.Container.dispatchEventImpl(Compiled Code)
at java.awt.Component.dispatchEvent(Compiled Code)
at java.awt.LightweightDispatcher.retargetMouseEvent(Compiled Code)
at java.awt.LightweightDispatcher.processMouseEvent(Compiled Code)
at java.awt.LightweightDispatcher.dispatchEvent(Compiled Code)
at java.awt.Container.dispatchEventImpl(Compiled Code)
at java.awt.Window.dispatchEventImpl(Compiled Code)
at java.awt.Component.dispatchEvent(Compiled Code)
at java.awt.EventQueue.dispatchEvent(Compiled Code)
at java.awt.EventDispatchThread.run(Compiled Code)

Things Tried:
1: If you set JTextArea.setWrapStyleWord(true) and then click in JTextArea and
  press End key all is well.
2: Tried the cricket release.


Testcase:

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

class SetWordWrap extends JFrame implements ActionListener {

  public SetWordWrap() {
    
    JPanel mainPanel = new JPanel(new BorderLayout());
    JPanel cbPanel = new JPanel();
    JPanel buttonPanel = new JPanel();
    JPanel statusPanel = new JPanel();
    JPanel bottomPanel = new JPanel(new BorderLayout());
    

    line = addCheckBox(cbPanel, "Word Wrap");

    /** For Debugging purpose
    test = addButton(buttonPanel,"Test",Color.yellow);
    */

    pass = addButton(buttonPanel,"Pass",Color.green);
    fail = addButton(buttonPanel,"Fail",Color.red);
    
    textArea.setWrapStyleWord(true);
    textArea.setText(text1);
    scrollPane = new JScrollPane(textArea);

    mainPanel.add(cbPanel,BorderLayout.NORTH);
    mainPanel.add(scrollPane,BorderLayout.CENTER);

    //Add Status Bar
    statusPanel.setBorder(BorderFactory.createEtchedBorder());
    statusPanel.setLayout(new FlowLayout(FlowLayout.LEFT,0,0));
    statusPanel.add(status);
    status.setHorizontalAlignment(JLabel.LEFT);

    bottomPanel.add(buttonPanel,BorderLayout.NORTH);
    bottomPanel.add(statusPanel,BorderLayout.SOUTH);

    contentPane.add(mainPanel, BorderLayout.NORTH);
    contentPane.add(bottomPanel, BorderLayout.SOUTH);

    // Add Window handler
    addWindowListener(new WindowAdapter(){
      public void windowClosing(WindowEvent event){ System.exit(0);}
    });
    
  }

  public static void main(String[] args) {
    SetWordWrap f = new SetWordWrap();
    f.setTitle("Word Wrap Test for JTextArea");
    f.pack();
    f.show();
  }

  
  public JButton addButton(JPanel addComponent, String name, Color color) {
    JButton b = new JButton(name);
    b.setBackground(color);
    b.addActionListener(this);
    addComponent.add(b);
    return b;
  }


  public JCheckBox addCheckBox(JPanel addComponent, String name) {
    JCheckBox c = new JCheckBox(name);
    c.addActionListener(this);
    addComponent.add(c);
    return c;
  }

  public void actionPerformed(ActionEvent evt) {
    String cmd = evt.getActionCommand();
    
    if (line.isSelected()) {
      textArea.setWrapStyleWord(true);
      status.setText(textStatus2);
    }
    else {
      textArea.setWrapStyleWord(false);
      status.setText(textStatus1);
    }

    if (evt.getSource() == pass) {
      System.out.println("Test Passed");
      System.exit(0);
    }
    else if (evt.getSource() == fail) {
      System.out.println("Test Failed");
      System.exit(1);
    }
    /** For Debugging purpose
    else if (evt.getSource() == test) {
      System.out.println(textArea.getWrapStyleWord());
    }
    */
  }

  private JScrollPane scrollPane;
  private JTextArea textArea = new JTextArea(8,25);
  private Container contentPane = getContentPane();
  private JCheckBox insert;
  private JCheckBox line;
  private JCheckBox word;
  private JLabel status = new JLabel("Toggle Line Wrap CheckBox on/off.");
  private String textStatus1 = "Text should be scrollable.";
  private String textStatus2 = "Does the text wrap to next line?";
  private String text1 = "This is a default String that should force word wrapping.";
  private JButton pass;
  private JButton fail;
  // private JButton test; // For debugging purpose
  private boolean state = true;


gary.collins@East 1999-05-05