8005930: [lcms] ColorConvertOp: Alpha channel is not transferred from source to destination

Reviewed-by: prr

jdk/src/share/classes/sun/java2d/cmm/lcms/LCMSTransform.java

@@ -163,13 +163,15 @@ public class LCMSTransform implements ColorTransform {
     public void colorConvert(BufferedImage src, BufferedImage dst) {
         LCMSImageLayout srcIL, dstIL;
 
-        dstIL = LCMSImageLayout.createImageLayout(dst);
+        if (!dst.getColorModel().hasAlpha()) {
+            dstIL = LCMSImageLayout.createImageLayout(dst);
 
-        if (dstIL != null) {
-            srcIL = LCMSImageLayout.createImageLayout(src);
-            if (srcIL != null) {
-                doTransform(srcIL, dstIL);
-                return;
+            if (dstIL != null) {
+                srcIL = LCMSImageLayout.createImageLayout(src);
+                if (srcIL != null) {
+                    doTransform(srcIL, dstIL);
+                    return;
+                }
             }
         }
 

jdk/test/sun/java2d/cmm/ColorConvertOp/AlphaTest.java

@@ -0,0 +1,99 @@
+/*
+ * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/**
+ * @test
+ * @bug     8005930
+ * @summary Thest verifies that color conversion does not distort
+ *          alpha channel in the destination image.
+ *
+ * @run     main AlphaTest
+ */
+
+import java.awt.AlphaComposite;
+import java.awt.Color;
+import java.awt.Graphics2D;
+import java.awt.color.ColorSpace;
+import java.awt.image.BufferedImage;
+import java.awt.image.ColorConvertOp;
+
+public class AlphaTest {
+    public static void main(String[] args) {
+        ColorSpace cs = ColorSpace.getInstance(ColorSpace.CS_GRAY);
+
+        ColorConvertOp op = new ColorConvertOp(cs, null);
+        // create source image filled with an opaque color
+        BufferedImage src = createSrc();
+        int srcAlpha = getAlpha(src);
+
+        System.out.printf("Src alpha: 0x%02x\n", srcAlpha);
+
+        // create clear (transparent black) destination image
+        BufferedImage dst = createDst();
+        int dstAlpha = getAlpha(dst);
+        System.out.printf("Dst alpha: 0x%02x\n", dstAlpha);
+
+
+        dst = op.filter(src, dst);
+        dstAlpha = getAlpha(dst);
+        // we expect that destination image is opaque
+        // i.e. alpha is transferred from source to
+        // the destination
+        System.out.printf("Result alpha: 0x%02x\n", dstAlpha);
+
+        if (srcAlpha != dstAlpha) {
+            throw new RuntimeException("Test failed!");
+        }
+        System.out.println("Test passed");
+    }
+
+    private static BufferedImage createSrc() {
+        BufferedImage img = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
+
+        Graphics2D g = img.createGraphics();
+        g.setColor(Color.red);
+        g.fillRect(0, 0, w, h);
+        g.dispose();
+
+        return img;
+    }
+
+    private static BufferedImage createDst() {
+        BufferedImage img = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
+
+        Graphics2D g = img.createGraphics();
+        g.setComposite(AlphaComposite.Clear);
+        g.fillRect(0, 0, w, h);
+        g.dispose();
+
+        return img;
+    }
+
+    private static int getAlpha(BufferedImage img) {
+        int argb = img.getRGB(w / 2, h / 2);
+        return 0xff & (argb >> 24);
+    }
+
+    private static final int w = 100;
+    private static final int h = 100;
+}