Allow multiple streams in input

bzip2 can handle inputs that consist of multiple concatenated bzip2 streams.
To support this functionality, the decoder needs to continue after seeing an
EOS marker because it may be followed by another bzip2 stream.

index.js

@@ -29,8 +29,8 @@ function unbzip2Stream() {
 
             streamCRC = bz2.decompress(bitReader, f, buf, bufsize, streamCRC);
             if (streamCRC === null) {
-                push(null);
-                //console.error('done');
+                // reset for next bzip2 header
+                blockSize = 0;
                 return false;
             }else{
                 //console.error('decompressed', chunk.length,'bytes');
@@ -71,16 +71,20 @@ function unbzip2Stream() {
                     return bufferQueue.shift();
                 });
             }
-            while (hasBytes - bitReader.bytesRead + 1 >= ((25000 + 100000 * blockSize) || 4)){
+            while (!broken && hasBytes - bitReader.bytesRead + 1 >= ((25000 + 100000 * blockSize) || 4)){
                 //console.error('decompressing with', hasBytes - bitReader.bytesRead + 1, 'bytes in buffer');
-                if (!done) done = !decompressAndQueue(this);
-                if (done) break;
+                decompressAndQueue(this);
             }
         },
         function end(x) {
             //console.error(x,'last compressing with', hasBytes, 'bytes in buffer');
-            if (!done) {
-                while(decompressAndQueue(this));
+            while (!broken && hasBytes > bitReader.bytesRead){
+                decompressAndQueue(this);
+            }
+            if (!broken) {
+                if (streamCRC !== null)
+                    stream.emit('error', new Error("input stream ended prematurely"));
+                this.queue(null);
             }
         }
     );

test/simple.js

@@ -17,6 +17,20 @@ test('one chunk of compressed data piped into unbzip2-stream results in original
 
 });
 
+test('concatenated bz2 streams piped into unbzip2-stream results in original file content', function(t) {
+    t.plan(1);
+    var compressed = fs.readFileSync('test/fixtures/concatenated.bz2');
+    var unbz2 = unbzip2Stream();
+    unbz2.pipe( concat(function(data) {
+        var expected = "ab\n";
+        t.equal(data.toString('utf-8'), expected);
+    }));
+
+    unbz2.write(compressed);
+    unbz2.end();
+
+});
+
 test('should emit error when stream is broken', function(t) {
     t.plan(1);
     var compressed = fs.readFileSync('test/fixtures/broken');