Strip trailing padding from HMEF compressed rtf when decoding

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1081414 13f79535-47bb-0310-9956-ffa450edef68

src/scratchpad/src/org/apache/poi/hmef/CompressedRTF.java

@@ -31,9 +31,6 @@ import org.apache.poi.util.LittleEndian;
  * Within a {@link HMEFMessage}, the content is often
  *  stored in as RTF, but LZW compressed. This class
  *  handles decompressing it for you.
- *  
- * Note - this doesn't quite decompress the data correctly,
- *  more work and unit testing is required...
  */
 public final class CompressedRTF extends LZWDecompresser {
    public static final byte[] COMPRESSED_SIGNATURE =
@@ -52,6 +49,9 @@ public final class CompressedRTF extends LZWDecompresser {
       "{\\rtf1\\ansi\\mac\\deff0\\deftab720{\\fonttbl;}{\\f0\\fnil \\froman \\fswiss " +
       "\\fmodern \\fscript \\fdecor MS Sans SerifSymbolArialTimes New RomanCourier" +
       "{\\colortbl\\red0\\green0\\blue0\n\r\\par \\pard\\plain\\f0\\fs20\\b\\i\\u\\tab\\tx";
+
+   private int compressedSize;
+   private int decompressedSize;
    
    public CompressedRTF() {
       // Out flag has the normal meaning
@@ -60,10 +60,18 @@ public final class CompressedRTF extends LZWDecompresser {
       super(true, 2, true);
    }
 
+   /**
+    * Decompresses the whole of the compressed RTF
+    *  stream, outputting the resulting RTF bytes.
+    * Note - will decompress any padding at the end of
+    *  the input, if present, use {@link #getDeCompressedSize()}
+    *  if you need to know how much of the result is
+    *  real. (Padding may be up to 7 bytes).
+    */
    public void decompress(InputStream src, OutputStream res) throws IOException {
       // Validate the header on the front of the RTF
-      int compressedSize = LittleEndian.readInt(src);
-      int uncompressedSize = LittleEndian.readInt(src);
+      compressedSize = LittleEndian.readInt(src);
+      decompressedSize = LittleEndian.readInt(src);
       int compressionType = LittleEndian.readInt(src);
       int dataCRC = LittleEndian.readInt(src);
       
@@ -82,6 +90,21 @@ public final class CompressedRTF extends LZWDecompresser {
       // Have it processed
       super.decompress(src, res);
    }
+   
+   /**
+    * Returns how big the compressed version was.
+    */
+   public int getCompressedSize() {
+      // Return the size less the header
+      return compressedSize - 12;
+   }
+   
+   /**
+    * Returns how big the decompressed version was.
+    */
+   public int getDeCompressedSize() {
+      return decompressedSize;
+   }
 
    /**
     * We use regular dictionary offsets, so no

src/scratchpad/src/org/apache/poi/hmef/attribute/MAPIRtfAttribute.java

@@ -37,9 +37,17 @@ public final class MAPIRtfAttribute extends MAPIAttribute {
    public MAPIRtfAttribute(MAPIProperty property, int type, byte[] data) throws IOException {
       super(property, type, data);
       
+      // Decompress it, removing any trailing padding as needed
       CompressedRTF rtf = new CompressedRTF();
-      this.decompressed = rtf.decompress(new ByteArrayInputStream(data));
+      byte[] tmp = rtf.decompress(new ByteArrayInputStream(data));
+      if(tmp.length > rtf.getDeCompressedSize()) {
+         this.decompressed = new byte[rtf.getDeCompressedSize()];
+         System.arraycopy(tmp, 0, decompressed, 0, decompressed.length);
+      } else {
+         this.decompressed = tmp;
+      }
       
+      // Turn the RTF data into a more useful string
       this.data = StringUtil.getFromCompressedUnicode(decompressed, 0, decompressed.length);
    }
    

src/scratchpad/testcases/org/apache/poi/hmef/TestCompressedRTF.java

@@ -148,7 +148,7 @@ public final class TestCompressedRTF extends TestCase {
      * Check that we can correctly decode the whole file
      * TODO Fix what looks like a padding issue
      */
-    public void DISABLEDtestFull() throws Exception {
+    public void testFull() throws Exception {
        HMEFMessage msg = new HMEFMessage(
              _samples.openResourceAsStream("quick-winmail.dat")
        );
@@ -160,11 +160,26 @@ public final class TestCompressedRTF extends TestCase {
        byte[] expected = IOUtils.toByteArray(
              _samples.openResourceAsStream("quick-contents/message.rtf")
        );
-       byte[] decomp = rtfAttr.getData();
+       
+       CompressedRTF comp = new CompressedRTF();
+       byte[] data = rtfAttr.getRawData();
+       byte[] decomp = comp.decompress(new ByteArrayInputStream(data));
+       
+       // Check the length was as expected
+       assertEquals(data.length, comp.getCompressedSize() + 16);
+       assertEquals(expected.length, comp.getDeCompressedSize()); 
+       
+       // Will have been padded though
+       assertEquals(expected.length+2, decomp.length);
+       byte[] tmp = new byte[expected.length];
+       System.arraycopy(decomp, 0, tmp, 0, tmp.length);
+       decomp = tmp;
        
        // By byte
        assertEquals(expected.length, decomp.length);
-       assertEquals(expected, decomp);
+       for(int i=0; i<expected.length; i++) {
+          assertEquals(expected[i], decomp[i]);
+       }
        
        // By String
        String expString = new String(expected, "ASCII");

src/scratchpad/testcases/org/apache/poi/hmef/TestHMEFMessage.java

@@ -103,9 +103,8 @@ public final class TestHMEFMessage extends HMEFTest {
    /**
     * Checks that the compressed RTF message contents
     *  can be correctly extracted
-    * TODO Fix what looks like a padding issue
     */
-   public void DISABLEDtestMessageContents() throws Exception {
+   public void testMessageContents() throws Exception {
       HMEFMessage msg = new HMEFMessage(
             _samples.openResourceAsStream("quick-winmail.dat")
       );