ADDITIONAL SYSTEM INFORMATION :
Windows 10.
Works on Java 8u201, Java 8u172.
Fails on Java 11.0.7, Java 11.0.9.1, Java 11.0.10, Java 15.0.2
PC has 2 monitors:
\Display0, logical size: 1440.0x2560.0, physical size: 2160x3840
\Display1, logical size: 1280.0x1024.0, physical size: 1280x1024)


A DESCRIPTION OF THE PROBLEM :
JTextArea, when used with a monospaced font and configured to a discrete number of columns, is not wrapping at the indicated number of columns.

REGRESSION : Last worked in version 8u281

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Create a JTextArea()
Set the font to monospaced.
Configure rows and columns to discrete values.
Enable wrap, but wrap on character, not word.
Give it more text in a single string than it has room to wrap.
Pack it into a frame and view.


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Text will wrap at the indicated character (character 35 in the provided SSCCE)
As the font is monospaced, it should in all cases wrap after the defined number of characters appear on a line of text.
ACTUAL -
Text wraps at the wrong spot (character 33 in my SSCCE)

---------- BEGIN SOURCE ----------
package buggy.textareawrap;

import java.awt.BorderLayout;
import java.awt.Font;

import javax.swing.JFrame;
import javax.swing.JTextArea;

public class TextWrapSscce2 {

public static void main(String[] args)
{
JFrame frame = new JFrame("SSCCE - Wordwrap test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
JTextArea textArea = new JTextArea();
Font font = Font.decode(Font.MONOSPACED);
textArea.setFont(font);
textArea.setRows(8);
textArea.setColumns(35);
textArea.setLineWrap(true);
textArea.setWrapStyleWord(false);

//Text should wrap just after the final numeral 5
String text = "Sample text for wrap test:\n"
+ "1234567890123456789012345678901234567890";
textArea.setText(text);

// Don't let the text area acquire space it doesn't claim to need
frame.add(textArea,BorderLayout.WEST);

frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
You can likely get around this by overriding the sizing logic.

FREQUENCY : always