ADDITIONAL SYSTEM INFORMATION :
Windows, Ubuntu at least
OpenJDK at least

A DESCRIPTION OF THE PROBLEM :
When calling the methods drawLine(x1,y1,x2,y2) on a Buffered image of type byte binary, for graphics 2d not being draw correctly,

@Override
public void paint(Graphics g1) {
BufferedImage colored = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_BYTE_BINARY);

Graphics2D g = colored.createGraphics();
g.setColor(Color.white);
g.fillRect(0, 0, getWidth(), getHeight());
g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
g.setColor(Color.black);

g.drawLine(40, 10, 0, 10);
g.drawLine(80, 21, 10, 20);
g.drawLine(120, 32, 20, 30);
g.drawLine(160, 43, 30, 40);
g.drawLine(50, 50, 200, 54);


g1.drawImage(colored, 0, 0, 300, 300, 0, 0, 300, 300, null);
}

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Create e JPanel inside a JFrame overriding paint method. Code bellow

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
complete lines
ACTUAL -
dashed lines

---------- BEGIN SOURCE ----------
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.WindowConstants;

public class JTestFrame extends JFrame {

public JTestFrame() {
super();
JTestPanel a = new JTestPanel();
a.setSize(300, 300);
a.setBackground(Color.BLACK);
add(a);
}


public static void main(String[] args) {
JTestFrame t = new JTestFrame();
t.setSize(300, 300);
t.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
t.setVisible(true);
}

private class JTestPanel extends JPanel {

@Override
public void paint(Graphics g1) {
BufferedImage colored = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_BYTE_BINARY);

Graphics2D g = colored.createGraphics();
g.setColor(Color.white);
g.fillRect(0, 0, getWidth(), getHeight());
g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
g.setColor(Color.black);

g.drawLine(40, 10, 0, 10);
g.drawLine(80, 21, 10, 20);
g.drawLine(120, 32, 20, 30);
g.drawLine(160, 43, 30, 40);
g.drawLine(50, 50, 200, 54);


g1.drawImage(colored, 0, 0, 300, 300, 0, 0, 300, 300, null);
}
}
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
this only happens when y1>y2, the workaround it to switch y2 for y1 and the respective x1 and x2