reset stream RTO if outbound tunnel was changed

libi2pd/Streaming.cpp

@@ -916,20 +916,32 @@ namespace stream
 			UpdateCurrentRemoteLease (true);
 		if (m_CurrentRemoteLease && ts < m_CurrentRemoteLease->endDate + i2p::data::LEASE_ENDDATE_THRESHOLD)
 		{
+			bool freshTunnel = false;
 			if (!m_CurrentOutboundTunnel)
 			{
 				auto leaseRouter = i2p::data::netdb.FindRouter (m_CurrentRemoteLease->tunnelGateway);
 				m_CurrentOutboundTunnel = m_LocalDestination.GetOwner ()->GetTunnelPool ()->GetNextOutboundTunnel (nullptr,
 					leaseRouter ? leaseRouter->GetCompatibleTransports (false) : (i2p::data::RouterInfo::CompatibleTransports)i2p::data::RouterInfo::eAllTransports);
+				freshTunnel = true;
 			}
 			else if (!m_CurrentOutboundTunnel->IsEstablished ())
+			{
+				auto oldOutboundTunnel = m_CurrentOutboundTunnel;
 				m_CurrentOutboundTunnel = m_LocalDestination.GetOwner ()->GetTunnelPool ()->GetNewOutboundTunnel (m_CurrentOutboundTunnel);
+				if (m_CurrentOutboundTunnel && oldOutboundTunnel->GetEndpointIdentHash() != m_CurrentOutboundTunnel->GetEndpointIdentHash())
+					freshTunnel = true;
+			}
 			if (!m_CurrentOutboundTunnel)
 			{
 				LogPrint (eLogError, "Streaming: No outbound tunnels in the pool, sSID=", m_SendStreamID);
 				m_CurrentRemoteLease = nullptr;
 				return;
 			}
+			if (freshTunnel)
+			{
+				m_RTO = INITIAL_RTO;
+				m_TunnelsChangeSequenceNumber = m_SequenceNumber; // should be determined more precisely
+			}
 
 			std::vector<i2p::tunnel::TunnelMessageBlock> msgs;
 			for (const auto& it: packets)