FULL PRODUCT VERSION :
java version "1.9.0-ea"
Java(TM) SE Runtime Environment (build 1.9.0-ea-b65)
Java HotSpot(TM) 64-Bit Server VM (build 1.9.0-ea-b65, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
os x version 10.8.5 build 12F45

A DESCRIPTION OF THE PROBLEM :
getPreferredSize of JTextArea is wrong.
the returned width is one pixel more than the current width


REGRESSION.  Last worked in version 8u60

ADDITIONAL REGRESSION INFORMATION: 
Java(TM) SE Runtime Environment (build 1.8.0_60-ea-b08)
Java HotSpot(TM) 64-Bit Server VM (build 25.60-b08, mixed mode)


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The preferred size should be not keep changing.
ACTUAL -
The preferred size keeps getting wider by one pixel.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.awt.Dimension;

import javax.swing.JTextArea;
import javax.swing.SwingUtilities;

public class JTextAreaPreferredSizeTest
{
	public static void main(String[] args)
	{
		SwingUtilities.invokeLater(new Runnable()
		{
			
			@Override
			public void run()
			{
				JTextArea textArea = new JTextArea("Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut vel mauris eget ante viverra bibendum in ut nulla. Donec varius suscipit arcu, vitae molestie ipsum pharetra eu. Aliquam suscipit sagittis justo. Aliquam erat volutpat. Vivamus dignissim lectus turpis, eget accumsan.");
				textArea.setLineWrap(true);

				for (int index = 0; index < 255; ++index)
				{
					Dimension size = textArea.getPreferredSize();
					textArea.setSize(size);
					
					System.out.println(size);
				}
			}
		});
	}
}

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