From 191beeeedaea8d72ee09171a0d6dc23c24460c2d Mon Sep 17 00:00:00 2001
From: Swen Mun <longfinfunnel@gmail.com>
Date: Thu, 25 Apr 2019 13:54:26 +0900
Subject: [PATCH] Replace outdated peer.

---
 Libplanet/Net/Swarm.cs | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/Libplanet/Net/Swarm.cs b/Libplanet/Net/Swarm.cs
index 6a86984d5f..be2d526120 100644
--- a/Libplanet/Net/Swarm.cs
+++ b/Libplanet/Net/Swarm.cs
@@ -1288,6 +1288,7 @@ CancellationToken cancellationToken
 
             if (IsUnknownPeer(sender))
             {
+                _logger.Debug("The sender of delta is unknown.");
                 if (IsDifferentProtocolVersion(sender))
                 {
                     var args = new DifferentProtocolVersionEventArgs
@@ -1336,13 +1337,20 @@ CancellationToken cancellationToken
 
         private bool IsUnknownPeer(Peer sender)
         {
-            if (_peers.Keys.All(p => !sender.PublicKey.Equals(p.PublicKey)))
+            Peer existing = _peers.Keys
+                .FirstOrDefault(p => sender.PublicKey.Equals(p.PublicKey));
+
+            if (existing is null)
             {
                 return true;
             }
 
-            if (_dealers.Keys.All(a => !sender.Address.Equals(a)))
+            if (!existing.EndPoint.Equals(sender.EndPoint))
             {
+                // Clear outdated existing peer.
+                _peers.Remove(existing);
+                CloseDealer(existing);
+
                 return true;
             }