Actually I broke BlockEncoder, but now it works.

src/main/java/org/at4j/comp/bzip2/BZip2OutputStream.java

@@ -263,6 +263,17 @@ public class BZip2OutputStream extends OutputStream
 		return this == o;
 	}
 
+	/**
+	 * Close the stream if the client has been sloppy about it.
+	 */
+	@Override
+	protected void finalize() throws Throwable
+	{
+		close();
+		super.finalize();
+	}
+
+
 	/**
 	 * Create a {@link BZip2EncoderExecutorService} that can be shared between
 	 * several {@link BZip2OutputStream}:s to spread the bzip2 encoding work

src/main/java/org/at4j/comp/bzip2/BlockEncoder.java

@@ -179,9 +179,9 @@ final class BlockEncoder
 	{
 		byte[] res = m_scratchpad.m_sequenceMap;
 		byte index = 0;
-		for (int i : symbols)
+		for (byte i : symbols)
 		{
-			res[symbols[i] & 0xFF] = index++;
+			res[i & 0xFF] = index++;
 		}
 		return res;
 	}
@@ -754,7 +754,7 @@ final class BlockEncoder
 	private void writeBlockHeader(final int blockChecksum, int bwFirstPointer, boolean[] seenDifferentBytes, MTFAndRLEResult mtfrle, HuffmanTreesAndUsage htau) throws IOException
 	{
 		// Block magic
-		for (int b : BLOCK_MAGIC) {
+		for (byte b : BLOCK_MAGIC) {
 			m_out.writeBitsLittleEndian(b & 0xFF, 8);
 		}
 		// Checksum

src/main/java/org/at4j/comp/bzip2/BlockOutputStream.java

@@ -307,7 +307,7 @@ final class BlockOutputStream extends OutputStream
 	@Override
 	public void write(final byte[] data) throws IOException
 	{
-		for (int datum : data) {
+		for (byte datum : data) {
 			write(datum & 0xFF);
 		}
 	}