try to pick an outbound tunnel with same endpoint instead expired

Streaming.cpp

@@ -597,7 +597,7 @@ namespace stream
 			}
 		}
 		if (!m_CurrentOutboundTunnel || !m_CurrentOutboundTunnel->IsEstablished ())
-			m_CurrentOutboundTunnel = m_LocalDestination.GetOwner ().GetTunnelPool ()->GetNextOutboundTunnel ();
+			m_CurrentOutboundTunnel = m_LocalDestination.GetOwner ().GetTunnelPool ()->GetNewOutboundTunnel (m_CurrentOutboundTunnel);
 		if (!m_CurrentOutboundTunnel)
 		{
 			LogPrint (eLogError, "No outbound tunnels in the pool");

TunnelPool.cpp

@@ -131,6 +131,23 @@ namespace tunnel
 		return tunnel;
 	}
 
+	std::shared_ptr<OutboundTunnel> TunnelPool::GetNewOutboundTunnel (std::shared_ptr<OutboundTunnel> old) const
+	{
+		if (old && old->IsEstablished ()) return old;
+		std::shared_ptr<OutboundTunnel> tunnel;	
+		if (old)
+		{
+			std::unique_lock<std::mutex> l(m_OutboundTunnelsMutex);	
+			for (auto it: m_OutboundTunnels)
+				if (it->IsEstablished () && old->GetEndpointRouter ()->GetIdentHash () == it->GetEndpointRouter ()->GetIdentHash ())
+					tunnel = it;
+		}
+	
+		if (!tunnel)
+			tunnel = GetNextOutboundTunnel ();		
+		return tunnel;
+	}
+
 	void TunnelPool::CreateTunnels ()
 	{
 		int num = 0;

TunnelPool.h

@@ -43,6 +43,7 @@ namespace tunnel
 			std::vector<std::shared_ptr<InboundTunnel> > GetInboundTunnels (int num) const;
 			std::shared_ptr<OutboundTunnel> GetNextOutboundTunnel (std::shared_ptr<OutboundTunnel> excluded = nullptr) const;
 			std::shared_ptr<InboundTunnel> GetNextInboundTunnel (std::shared_ptr<InboundTunnel> excluded = nullptr) const;		
+			std::shared_ptr<OutboundTunnel> GetNewOutboundTunnel (std::shared_ptr<OutboundTunnel> old) const;
 
 			void TestTunnels ();
 			void ProcessGarlicMessage (I2NPMessage * msg);