#276 Fix DHT inconsistency

imageio/imageio-jpeg/src/main/java/com/twelvemonkeys/imageio/plugins/jpeg/JPEGImage10MetadataCleaner.java

@@ -197,9 +197,7 @@ final class JPEGImage10MetadataCleaner {
             IIOMetadataNode unknown = new IIOMetadataNode("unknown");
             unknown.setAttribute("MarkerTag", Integer.toString(segment.marker() & 0xff));
 
-            DataInputStream stream = new DataInputStream(segment.data());
-
-            try {
+            try (DataInputStream stream = new DataInputStream(segment.data())) {
                 String identifier = segment.identifier();
                 int off = identifier != null ? identifier.length() + 1 : 0;
 
@@ -213,9 +211,6 @@ final class JPEGImage10MetadataCleaner {
 
                 unknown.setUserObject(data);
             }
-            finally {
-                stream.close();
-            }
 
             if (next == null) {
                 // To be semi-compatible with the functionality in mergeTree,
@@ -271,12 +266,12 @@ final class JPEGImage10MetadataCleaner {
                 dht.getParentNode().insertBefore(acTables, dht.getNextSibling());
 
                 // Split into 2 dht nodes, one for AC and one for DC
-                for (int i = 0; i < dhtables.getLength(); i++) {
+                for (int i = dhtables.getLength() - 1; i >= 0 ; i--) {
                     Element dhtable = (Element) dhtables.item(i);
                     String tableClass = dhtable.getAttribute("class");
                     if ("1".equals(tableClass)) {
                         dht.removeChild(dhtable);
-                        acTables.appendChild(dhtable);
+                        acTables.insertBefore(dhtable, acTables.getFirstChild());
                     }
                 }
             }

imageio/imageio-jpeg/src/test/java/com/twelvemonkeys/imageio/plugins/jpeg/JPEGImage10MetadataCleanerTest.java

@@ -0,0 +1,96 @@
+package com.twelvemonkeys.imageio.plugins.jpeg;
+
+import com.twelvemonkeys.imageio.stream.URLImageInputStreamSpi;
+import org.junit.Test;
+import org.w3c.dom.Element;
+import org.w3c.dom.NodeList;
+
+import javax.imageio.ImageIO;
+import javax.imageio.ImageReader;
+import javax.imageio.metadata.IIOMetadata;
+import javax.imageio.metadata.IIOMetadataNode;
+import javax.imageio.spi.IIORegistry;
+import javax.imageio.spi.ImageReaderSpi;
+import javax.imageio.stream.ImageInputStream;
+import java.util.Arrays;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+/**
+ * JPEGImage10MetadataCleanerTest.
+ *
+ * @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
+ * @author last modified by $Author: harald.kuhr$
+ * @version $Id: JPEGImage10MetadataCleanerTest.java,v 1.0 08/08/16 harald.kuhr Exp$
+ */
+public class JPEGImage10MetadataCleanerTest {
+
+    static {
+        IIORegistry.getDefaultInstance().registerServiceProvider(new URLImageInputStreamSpi());
+        ImageIO.setUseCache(false);
+    }
+
+    protected static final JPEGImageReaderSpi SPI = new JPEGImageReaderSpi(lookupDelegateProvider());
+
+    protected static ImageReaderSpi lookupDelegateProvider() {
+        return JPEGImageReaderSpi.lookupDelegateProvider(IIORegistry.getDefaultInstance());
+    }
+
+    // Unit/regression test for #276
+    @Test
+    public void cleanMetadataMoreThan4DHTSegments() throws Exception {
+        List<String> testData = Arrays.asList("/jpeg/5dhtsegments.jpg", "/jpeg/6dhtsegments.jpg");
+
+        for (String data : testData) {
+            try (ImageInputStream origInput = ImageIO.createImageInputStream(getClass().getResource(data));
+                 ImageInputStream input = ImageIO.createImageInputStream(getClass().getResource(data))) {
+
+                ImageReader origReader = SPI.delegateProvider.createReaderInstance();
+                origReader.setInput(origInput);
+
+                ImageReader reader = SPI.createReaderInstance();
+                reader.setInput(input);
+
+                IIOMetadata original = origReader.getImageMetadata(0);
+                IIOMetadataNode origTree = (IIOMetadataNode) original.getAsTree(JPEGImage10MetadataCleaner.JAVAX_IMAGEIO_JPEG_IMAGE_1_0);
+
+                JPEGImage10MetadataCleaner cleaner = new JPEGImage10MetadataCleaner((JPEGImageReader) reader);
+                IIOMetadata cleaned = cleaner.cleanMetadata(origReader.getImageMetadata(0));
+
+                IIOMetadataNode cleanTree = (IIOMetadataNode) cleaned.getAsTree(JPEGImage10MetadataCleaner.JAVAX_IMAGEIO_JPEG_IMAGE_1_0);
+
+                NodeList origDHT = origTree.getElementsByTagName("dht");
+                assertEquals(1, origDHT.getLength());
+
+                NodeList cleanDHT = cleanTree.getElementsByTagName("dht");
+                assertEquals(2, cleanDHT.getLength());
+
+                NodeList cleanDHTable = cleanTree.getElementsByTagName("dhtable");
+                NodeList origDHTable = origTree.getElementsByTagName("dhtable");
+
+                assertEquals(origDHTable.getLength(), cleanDHTable.getLength());
+
+                // Note: This also tests that the order of the htables are the same,
+                // but that will only hold if they are already sorted by class.
+                // Luckily, they are in these cases...
+                for (int i = 0; i < origDHTable.getLength(); i++) {
+                    Element cleanDHTableElem = (Element) cleanDHTable.item(i);
+                    Element origDHTableElem = (Element) origDHTable.item(i);
+
+                    assertNotNull(cleanDHTableElem);
+
+                    assertNotNull(cleanDHTableElem.getAttribute("class"));
+                    assertEquals(origDHTableElem.getAttribute("class"), cleanDHTableElem.getAttribute("class"));
+
+                    assertNotNull(cleanDHTableElem.getAttribute("htableId"));
+                    assertEquals(origDHTableElem.getAttribute("htableId"), cleanDHTableElem.getAttribute("htableId"));
+                }
+
+                reader.dispose();
+                origReader.dispose();
+            }
+        }
+    }
+}