fixed potential issue where a piece could be checked twice

ChangeLog

@@ -28,6 +28,7 @@
 	  incoming connection
 	* added more detailed instrumentation of the disk I/O thread
 
+	* fixed potential issue where a piece could be checked twice
 	* fixed build issue on windows related to GetCompressedSize()
 	* fixed deadlock when starting torrents with certain invalid tracker URLs
 	* fixed iterator bug in disk I/O thread

src/peer_connection.cpp

@@ -2352,6 +2352,7 @@ namespace libtorrent
 			m_timeout_extend = 0;
 		}
 
+		bool was_finished = picker.is_piece_finished(p.piece);
 		// did we request this block from any other peers?
 		bool multi = picker.num_peers(block_finished) > 1;
 		picker.mark_as_writing(block_finished, peer_info_struct());
@@ -2370,7 +2371,7 @@ namespace libtorrent
 		// did we just finish the piece?
 		// this means all blocks are either written
 		// to disk or are in the disk write cache
-		if (picker.is_piece_finished(p.piece))
+		if (picker.is_piece_finished(p.piece) && !was_finished)
 		{
 #ifdef TORRENT_DEBUG
 			check_postcondition post_checker2_(t, false);

src/torrent.cpp

@@ -677,6 +677,8 @@ namespace libtorrent
 		// avoid crash trying to access the picker when there is nont
 		if (is_seed()) return;
 
+		if (picker().have_piece(piece)) return;
+
 		peer_request p;
 		p.piece = piece;
 		p.start = 0;
@@ -739,13 +741,6 @@ namespace libtorrent
 		m_need_save_resume_data = true;
 
 		picker().mark_as_finished(block_finished, 0);
-
-		// did we just finish the piece?
-		if (picker().is_piece_finished(p.piece))
-		{
-			async_verify_piece(p.piece, bind(&torrent::piece_finished, shared_from_this()
-				, p.piece, _1));
-		}
 	}
 	
 	void torrent::on_disk_cache_complete(int ret, disk_io_job const& j)
@@ -2106,6 +2101,8 @@ namespace libtorrent
 
 		TORRENT_ASSERT(valid_metadata());
 
+		TORRENT_ASSERT(!m_picker->have_piece(index));
+
 		// even though the piece passed the hash-check
 		// it might still have failed being written to disk
 		// if so, piece_picker::write_failed() has been