Bug #42476:

- fix NPE in XMLReader when no handler is found for the image
- prevent SVGReader from closing the input stream if the image actually isn't SVG
- reduce log level in SVGReader and XMLReader to avoid "false positive" (read error reported whereas the image format actually isn't recognized). This may hide regular I/O errors to the end-user, but I assume this will be rare enough compared to the annoyance of such messages when third-party plugins are used.

Patch submitted by Max Berger (max.at.berger.name)


git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@542447 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/fop/image/analyser/ImageReaderFactory.java

@@ -87,6 +87,8 @@ public class ImageReaderFactory {
                     return info;
                 }
             }
+            log.warn("No ImageReader found for " + uri);
+            in.close();
         } catch (IOException ex) {
             log.error("Error while recovering Image Informations ("
                 + uri + ")", ex);

src/java/org/apache/fop/image/analyser/SVGReader.java

@@ -43,6 +43,7 @@ import org.apache.fop.image.XMLImage;
 import org.apache.fop.image.FopImage;
 import org.apache.fop.apps.FOUserAgent;
 import org.apache.fop.svg.SVGUserAgent;
+import org.apache.fop.util.UnclosableInputStream;
 
 /** 
  * ImageReader object for SVG document image type.
@@ -112,58 +113,7 @@ public class SVGReader implements ImageReader {
             // parse document and get the size attributes of the svg element
 
             try {
-                int length = 5;
-                fis.mark(length);
-                byte[] b = new byte[length];
-                fis.read(b);
-                String start = new String(b);
-                fis.reset();
-
-                //TODO "true ||" here is a hack to improve SVG detection rate. Please improve.
-                if (true || start.equals("<?xml")) {
-                    // we have xml, might be another doc
-                    // so stop batik from closing the stream
-                    final InputStream input = fis;
-                    fis =
-                        new InputStream() {
-                            public int read() throws IOException {
-                                return input.read();
-                            }
-
-                            public int read(byte[] b) throws IOException {
-                                return input.read(b);
-                            }
-
-                            public int read(byte[] b, int off, int len)
-                                    throws IOException {
-                                return input.read(b, off, len);
-                            }
-
-                            public long skip(long n) throws IOException {
-                                return input.skip(n);
-                            }
-
-                            public int available() throws IOException {
-                                return input.available();
-                            }
-
-                            public void mark(int rl) {
-                                input.mark(rl);
-                            }
-
-                            public boolean markSupported() {
-                                return input.markSupported();
-                            }
-
-                            public void reset() throws IOException {
-                                input.reset();
-                            }
-
-                            public void close() throws IOException {
-                                //ignore
-                            }
-                        };
-                }
+                fis = new UnclosableInputStream(fis);
 
                 FopImage.ImageInfo info = new FopImage.ImageInfo();
 
@@ -175,7 +125,7 @@ public class SVGReader implements ImageReader {
                 info.mimeType = getMimeType();
                 info.str = SVGDOMImplementation.SVG_NAMESPACE_URI;
 
-                length = fis.available();
+                int length = fis.available();
                 fis.mark(length + 1);
                 SAXSVGDocumentFactory factory = new SAXSVGDocumentFactory(
                         XMLImage.getParserName());
@@ -217,7 +167,7 @@ public class SVGReader implements ImageReader {
                 batik = false;
                 log.warn("Batik not in class path", ncdfe);
                 return null;
-            } catch (Exception e) {
+            } catch (IOException e) {
                 // If the svg is invalid then it throws an IOException
                 // so there is no way of knowing if it is an svg document
 

src/java/org/apache/fop/image/analyser/XMLReader.java

@@ -31,6 +31,7 @@ import org.w3c.dom.Element;
 
 // FOP
 import org.apache.fop.image.FopImage;
+import org.apache.fop.util.UnclosableInputStream;
 import org.apache.fop.apps.FOUserAgent;
 
 // Commons-Logging
@@ -63,8 +64,8 @@ public class XMLReader implements ImageReader {
             FOUserAgent ua)
         throws IOException {
         FopImage.ImageInfo info = loadImage(uri, fis, ua);
-        info.originalURI = uri;
         if (info != null) {
+            info.originalURI = uri;
             IOUtils.closeQuietly(fis);
         }
         return info;
@@ -98,16 +99,17 @@ public class XMLReader implements ImageReader {
     /**
      * Creates an ImageInfo object from an XML image read from a stream.
      *
-     * @param is  The InputStream
+     * @param input  The InputStream
      * @param ua  The user agent
      * @return    An ImageInfo object describing the image
      */
-    public FopImage.ImageInfo createDocument(InputStream is, FOUserAgent ua) {
+    public FopImage.ImageInfo createDocument(final InputStream input, final FOUserAgent ua) {
         Document doc = null;
         FopImage.ImageInfo info = new FopImage.ImageInfo();
         info.mimeType = getMimeType();
 
         try {
+            final InputStream is = new UnclosableInputStream(input);
             int length = is.available();
             is.mark(length);
 
@@ -128,14 +130,21 @@ public class XMLReader implements ImageReader {
                 }
             }
         } catch (Exception e) {
-            log.warn("Error while constructing image from XML", e);
+            log.debug("Error while constructing image from XML", e);
             try {
-                is.reset();
+                input.reset();
             } catch (IOException ioe) {
                 // throw the original exception, not this one
             }
             return null;
         }
+        if (info != null) {
+            try {
+                input.close();
+            } catch (IOException io) {
+                // ignore
+            }
+        }
         return info;
     }
 

src/java/org/apache/fop/util/UnclosableInputStream.java

@@ -0,0 +1,46 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ * 
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/* $Id$ */
+
+package org.apache.fop.util;
+
+import java.io.FilterInputStream;
+import java.io.InputStream;
+
+/**
+ * Provides an InputStreamFilter which avoids closing the original stream.
+ */
+public class UnclosableInputStream extends FilterInputStream {
+
+    /**
+     * Default constructor.
+     * 
+     * @param in the Stream to filter.
+     */
+    public UnclosableInputStream(InputStream in) {
+        super(in);
+    }
+
+    /**
+     * Does <strong>not</strong> close the original stream.
+     */
+    public void close() {
+        // ignore
+    }
+
+}