fix bug where seeking past the end of the stream could cause an infinite loop

diff --git a/src/libFLAC/seekable_stream_decoder.c b/src/libFLAC/seekable_stream_decoder.c
index eb8cc4f..3cea37b 100644 (file)
--- a/src/libFLAC/seekable_stream_decoder.c
+++ b/src/libFLAC/seekable_stream_decoder.c
@@ -644,7 +644,7 @@ FLAC_API FLAC__bool FLAC__seekable_stream_decoder_seek_absolute(FLAC__SeekableSt
        FLAC__uint64 length;
 
        FLAC__ASSERT(0 != decoder);
-       FLAC__ASSERT(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_OK || decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM);
+       FLAC__ASSERT(decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_OK /*@@@@@ why shouldn't you be able to do this? || decoder->protected_->state == FLAC__SEEKABLE_STREAM_DECODER_END_OF_STREAM*/);
 
        decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEKING;
 
@@ -669,7 +669,7 @@ FLAC_API FLAC__bool FLAC__seekable_stream_decoder_seek_absolute(FLAC__SeekableSt
                decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_STREAM_DECODER_ERROR;
                return false;
        }
-       if(decoder->private_->stream_info.total_samples > 0 && sample > decoder->private_->stream_info.total_samples) {
+       if(decoder->private_->stream_info.total_samples > 0 && sample >= decoder->private_->stream_info.total_samples) {
                decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
                return false;
        }
@@ -982,8 +982,8 @@ FLAC__bool seek_to_absolute_sample_(FLAC__SeekableStreamDecoder *decoder, FLAC__
                else { /* we need to narrow the search */
                        FLAC__uint64 this_frame_sample = decoder->private_->last_frame.header.number.sample_number;
                        FLAC__ASSERT(decoder->private_->last_frame.header.number_type == FLAC__FRAME_NUMBER_TYPE_SAMPLE_NUMBER);
-                       if(this_frame_sample == last_frame_sample) {
-                               /* our last move backwards wasn't big enough */
+                       if(this_frame_sample == last_frame_sample && pos < last_pos) {
+                               /* our last move backwards wasn't big enough, double it */
                                pos -= (last_pos - pos);
                                needs_seek = true;
                        }
@@ -1004,6 +1004,14 @@ FLAC__bool seek_to_absolute_sample_(FLAC__SeekableStreamDecoder *decoder, FLAC__
                                        pos = (FLAC__int32)upos;
                                        pos -= FLAC__stream_decoder_get_input_bytes_unconsumed(decoder->private_->stream_decoder);
                                        needs_seek = false;
+                                       /*
+                                        * if we haven't hit the target frame yet and our position hasn't changed,
+                                        * it means we're at the end of the stream and the seek target does not exist.
+                                        */
+                                       if(last_pos == pos) {
+                                               decoder->protected_->state = FLAC__SEEKABLE_STREAM_DECODER_SEEK_ERROR;
+                                               return false;
+                                       }
                                }
                        }
                        if(pos < (FLAC__int64)lower_bound)