Improvements to file transfer:

- corrected 2 potential flaws of swarming causing request of unavailable data (This should normally be taken care of on the server side!)
- improved swarming test code with fault simulation
- only ask CRC32 maps to peers that have a complete file.
 


git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@4947 b45a01b8-16f6-495d-af2f-9b41ad6348cc

libretroshare/src/ft/ftchunkmap.h

@@ -84,6 +84,16 @@ class SourceChunksInfo
 		CompressedChunkMap cmap ;	//! map of what the peer has/doens't have
 		time_t TS ;						//! last update time for this info
 		bool is_full ;					//! is the map full ? In such a case, re-asking for it is unnecessary.
+
+		// Returns true if the offset is starting in a mapped chunk.
+		//
+		bool hasData(uint64_t offset,uint32_t fixed_chunk_size) const
+		{
+			if(is_full)
+				return true ;
+
+			return cmap[offset / (uint64_t)fixed_chunk_size ] ;
+		}
 };
 
 class ChunkMap