--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/test/javax/swing/JComponent/6683775/bug6683775.java	Thu May 21 12:29:25 2009 +0400
@@ -0,0 +1,82 @@
+/* @test
+   @bug 6683775 6794764
+   @summary Painting artifacts is seen when panel is made setOpaque(false) for a translucent window
+   @author Alexander Potochkin
+   @run main bug6683775
+*/
+
+import com.sun.awt.AWTUtilities;
+import sun.awt.SunToolkit;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.image.BufferedImage;
+
+public class bug6683775 {
+    public static void main(String[] args) throws Exception {
+        GraphicsConfiguration gc = getGC();
+        if (!AWTUtilities.isTranslucencySupported(
+                AWTUtilities.Translucency.PERPIXEL_TRANSLUCENT)
+                || gc == null) {
+            return;
+        }
+        SunToolkit toolkit = (SunToolkit) Toolkit.getDefaultToolkit();
+        Robot robot = new Robot();
+        final JFrame testFrame = new JFrame(gc);
+
+        SwingUtilities.invokeLater(new Runnable() {
+            public void run() {
+                JFrame backgroundFrame = new JFrame("Background frame");
+                backgroundFrame.setUndecorated(true);
+                JPanel panel = new JPanel();
+                panel.setBackground(Color.RED);
+                backgroundFrame.add(panel);
+                backgroundFrame.setSize(200, 200);
+                backgroundFrame.setVisible(true);
+
+                testFrame.setUndecorated(true);
+                JPanel p = new JPanel();
+                p.setOpaque(false);
+                testFrame.add(p);
+                AWTUtilities.setWindowOpaque(testFrame, false);
+                testFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+                testFrame.setSize(400, 400);
+                testFrame.setLocation(0, 0);
+                testFrame.setVisible(true);
+            }
+        });
+
+        toolkit.realSync();
+
+        //robot.getPixelColor() didn't work right for some reason
+        BufferedImage capture = robot.createScreenCapture(new Rectangle(100, 100));
+
+        int redRGB = Color.RED.getRGB();
+        if (redRGB != capture.getRGB(10, 10)) {
+            throw new RuntimeException("Transparent frame is not transparent!");
+        }
+    }
+
+    private static GraphicsConfiguration getGC() {
+        GraphicsConfiguration transparencyCapableGC =
+                GraphicsEnvironment.getLocalGraphicsEnvironment()
+                        .getDefaultScreenDevice().getDefaultConfiguration();
+        if (!AWTUtilities.isTranslucencyCapable(transparencyCapableGC)) {
+            transparencyCapableGC = null;
+
+            GraphicsEnvironment env =
+                    GraphicsEnvironment.getLocalGraphicsEnvironment();
+            GraphicsDevice[] devices = env.getScreenDevices();
+
+            for (int i = 0; i < devices.length && transparencyCapableGC == null; i++) {
+                GraphicsConfiguration[] configs = devices[i].getConfigurations();
+                for (int j = 0; j < configs.length && transparencyCapableGC == null; j++) {
+                    if (AWTUtilities.isTranslucencyCapable(configs[j])) {
+                        transparencyCapableGC = configs[j];
+                    }
+                }
+            }
+        }
+        return transparencyCapableGC;
+    }
+}