decoer/dsdiff: fix endless loop on malformed file

NEWS

 ver 0.18.13 (not yet released)
 * decoder
-  - dsf: fix endless loop on malformed file
+  - dsdiff, dsf: fix endless loop on malformed file
   - ffmpeg: support ffmpeg/libav version 11
 
 ver 0.18.12 (2014/07/30)

src/decoder/DsdiffDecoderPlugin.cxx

@@ -377,7 +377,7 @@ dsdiff_decode_chunk(Decoder &decoder, InputStream &is,
 	const unsigned buffer_samples = buffer_frames * frame_size;
 	const size_t buffer_size = buffer_samples * sample_size;
 
-	while (chunk_size > 0) {
+	while (chunk_size >= frame_size) {
 		/* see how much aligned data from the remaining chunk
 		   fits into the local buffer */
 		size_t now_size = buffer_size;