Bug 12314

Description David Wegener 2002-03-26 15:31:11 EST

Build 20020321 Stable
While trying to step into the String constructor, I receive an Application 
Error: The instruction at "0x504cd71f" referenced memory at "0x00000000". The 
memory could not be "read".  The error occurs in the VM being debugged, so 
Eclipse isn't crashing.

I am able to reproduce this problem and even have a simple example that 
displays the problem.  The problem occurs when debugging on the Sun jdk1.2.2 
fullversion:JDK-1.2.2_008

Here is the example code.  Run the DebugStringTest class with a breakpoint set 
in the insertString() method of the DebugTestDocument class.  When the frame is 
displayed, enter a character, step into while on the line marked in the 
source.  This will attempt to step into the String constructor.  This is where 
I get the error.

---------------------------------------------------
package debug.test;

import javax.swing.JFrame;
import javax.swing.JTextField;

import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;

public class DebugStringTest extends JFrame {
	private JTextField testField;
	/**
	 * Constructor for DebugStringTest.
	 */
	public DebugStringTest() {
		testField = new JTextField();
		testField.setDocument(new DebugTestDocument());
		testField.setPreferredSize(new Dimension(150,50));
		Container content = getContentPane();
		content.setLayout((new FlowLayout(FlowLayout.LEFT)));
		content.add(testField);
	}

	/**
	 * Constructor for DebugStringTest.
	 * @param title
	 */
	public DebugStringTest(String title) {
		super(title);
	}

	public static void main(String[] args) {
		DebugStringTest test = new DebugStringTest();
		test.pack();
		test.show();
		
	}
}


--------------------------------------------------------



package debug.test;

import javax.swing.text.PlainDocument;
import javax.swing.text.AbstractDocument.Content;

public class DebugTestDocument extends PlainDocument {
	/**
 * This method was created in VisualAge.
 * @param offs int
 * @param str java.lang.String
 * @param a AttributeSet
 * @exception javax.swing.text.BadLocationException The exception description.
 */
public void insertString( int offs, String str, javax.swing.text.AttributeSet 
a ) throws javax.swing.text.BadLocationException {
	if( str == null ) {
		return;
	}
	
	char[] upper = str.toCharArray();
	for( int i = 0; i < upper.length; i++ ) {
		upper[i] = Character.toUpperCase( upper[i] );
	}
	super.insertString( offs, new String(upper), a);  //<--- breakpoint 
here, then step into
	
}


	/**
	 * Constructor for DebugTestDocument.
	 */
	public DebugTestDocument() {
		super();
	}

	/**
	 * Constructor for DebugTestDocument.
	 * @param arg0
	 */
	protected DebugTestDocument(Content arg0) {
		super(arg0);
	}

}