Minor sync bug.

libethereum/BlockChain.cpp

@@ -329,7 +329,7 @@ h256s BlockChain::import(bytes const& _block, OverlayDB const& _db)
 	return ret;
 }
 
-h256s BlockChain::treeRoute(h256 _from, h256 _to, h256* o_common) const
+h256s BlockChain::treeRoute(h256 _from, h256 _to, h256* o_common, bool _pre, bool _post) const
 {
 	h256s ret;
 	h256s back;
@@ -337,20 +337,24 @@ h256s BlockChain::treeRoute(h256 _from, h256 _to, h256* o_common) const
 	unsigned tn = details(_to).number;
 	while (fn > tn)
 	{
-		ret.push_back(_from);
+		if (_pre)
+			ret.push_back(_from);
 		_from = details(_from).parent;
 		fn--;
 	}
 	while (fn < tn)
 	{
-		back.push_back(_to);
+		if (_post)
+			back.push_back(_to);
 		_to = details(_to).parent;
 		tn--;
 	}
 	while (_from != _to)
 	{
-		_from = details(_from).parent;
-		_to = details(_to).parent;
+		if (_pre)
+			_from = details(_from).parent;
+		if (_post)
+			_to = details(_to).parent;
 		ret.push_back(_from);
 		back.push_back(_to);
 	}

libethereum/BlockChain.h

@@ -128,7 +128,7 @@ public:
 	 * treeRoute(1b, 2a) == { 1b, 1a, 2a }; // *o_common == g
 	 * @endcode
 	 */
-	h256s treeRoute(h256 _from, h256 _to, h256* o_common = nullptr) const;
+	h256s treeRoute(h256 _from, h256 _to, h256* o_common = nullptr, bool _pre = true, bool _post = true) const;
 
 private:
 	template<class T, unsigned N> T queryExtras(h256 _h, std::map<h256, T>& _m, boost::shared_mutex& _x, T const& _n) const

libethereum/PeerServer.cpp

@@ -507,12 +507,18 @@ void PeerServer::maintainBlocks(BlockQueue& _bq, h256 _currentHash)
 	// Send any new blocks.
 	if (_currentHash != m_latestBlockSent)
 	{
-		// TODO: find where they diverge and send complete new branch.
 		RLPStream ts;
 		PeerSession::prep(ts);
-		ts.appendList(2) << BlocksPacket;
+		bytes bs;
+		unsigned c = 0;
+		for (auto h: m_chain->treeRoute(m_latestBlockSent, _currentHash, nullptr, false, true))
+		{
+			bs += m_chain->block(h);
+			++c;
+		}
+		ts.appendList(1 + c).append(BlocksPacket).appendRaw(bs, c);
 		bytes b;
-		ts.appendRaw(m_chain->block()).swapOut(b);
+		ts.swapOut(b);
 		seal(b);
 
 		Guard l(x_peers);