From 7da90af2f48da480881e1c7fb7b02c01f0a949a5 Mon Sep 17 00:00:00 2001
From: Patric Stout <truebrain@openttd.org>
Date: Sat, 27 Feb 2021 10:50:41 +0100
Subject: [PATCH] Fix: [Network] send map to next client if current client
 disconnects

Also terminate creating of the savegame, as the client is gone,
there really is no need for that anymore.

(cherry picked from commit 8d199b1bbc2f7f0db98b47b709b75ff97b23e730)
---
 src/network/network_server.cpp | 59 ++++++++++++++++++++++------------
 src/network/network_server.h   |  2 ++
 2 files changed, 40 insertions(+), 21 deletions(-)

diff --git a/src/network/network_server.cpp b/src/network/network_server.cpp
index 421fc9907e..70238b17ec 100644
--- a/src/network/network_server.cpp
+++ b/src/network/network_server.cpp
@@ -280,6 +280,16 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::CloseConnection(NetworkRecvSta
 		}
 	}
 
+	/* If we were transfering a map to this client, stop the savegame creation
+	 * process and queue the next client to receive the map. */
+	if (this->status == STATUS_MAP) {
+		/* Ensure the saving of the game is stopped too. */
+		this->savegame->Destroy();
+		this->savegame = nullptr;
+
+		this->CheckNextClientToSendMap(this);
+	}
+
 	NetworkAdminClientError(this->client_id, NETWORK_ERROR_CONNECTION_LOST);
 	DEBUG(net, 1, "Closed client connection %d", this->client_id);
 
@@ -590,6 +600,33 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::SendWait()
 	return NETWORK_RECV_STATUS_OKAY;
 }
 
+void ServerNetworkGameSocketHandler::CheckNextClientToSendMap(NetworkClientSocket *ignore_cs)
+{
+	/* Find the best candidate for joining, i.e. the first joiner. */
+	NetworkClientSocket *best = nullptr;
+	for (NetworkClientSocket *new_cs : NetworkClientSocket::Iterate()) {
+		if (ignore_cs == new_cs) continue;
+
+		if (new_cs->status == STATUS_MAP_WAIT) {
+			if (best == nullptr || best->GetInfo()->join_date > new_cs->GetInfo()->join_date || (best->GetInfo()->join_date == new_cs->GetInfo()->join_date && best->client_id > new_cs->client_id)) {
+				best = new_cs;
+			}
+		}
+	}
+
+	/* Is there someone else to join? */
+	if (best != nullptr) {
+		/* Let the first start joining. */
+		best->status = STATUS_AUTHORIZED;
+		best->SendMap();
+
+		/* And update the rest. */
+		for (NetworkClientSocket *new_cs : NetworkClientSocket::Iterate()) {
+			if (new_cs->status == STATUS_MAP_WAIT) new_cs->SendWait();
+		}
+	}
+}
+
 /** This sends the map to the client */
 NetworkRecvStatus ServerNetworkGameSocketHandler::SendMap()
 {
@@ -649,27 +686,7 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::SendMap()
 			 *  to send it is ready (maybe that happens like never ;)) */
 			this->status = STATUS_DONE_MAP;
 
-			/* Find the best candidate for joining, i.e. the first joiner. */
-			NetworkClientSocket *best = nullptr;
-			for (NetworkClientSocket *new_cs : NetworkClientSocket::Iterate()) {
-				if (new_cs->status == STATUS_MAP_WAIT) {
-					if (best == nullptr || best->GetInfo()->join_date > new_cs->GetInfo()->join_date || (best->GetInfo()->join_date == new_cs->GetInfo()->join_date && best->client_id > new_cs->client_id)) {
-						best = new_cs;
-					}
-				}
-			}
-
-			/* Is there someone else to join? */
-			if (best != nullptr) {
-				/* Let the first start joining. */
-				best->status = STATUS_AUTHORIZED;
-				best->SendMap();
-
-				/* And update the rest. */
-				for (NetworkClientSocket *new_cs : NetworkClientSocket::Iterate()) {
-					if (new_cs->status == STATUS_MAP_WAIT) new_cs->SendWait();
-				}
-			}
+			this->CheckNextClientToSendMap();
 		}
 
 		switch (this->SendPackets()) {
diff --git a/src/network/network_server.h b/src/network/network_server.h
index 12a65bd81e..0f1d3ee29a 100644
--- a/src/network/network_server.h
+++ b/src/network/network_server.h
@@ -89,6 +89,8 @@ public:
 	NetworkRecvStatus CloseConnection(NetworkRecvStatus status) override;
 	void GetClientName(char *client_name, const char *last) const;
 
+	void CheckNextClientToSendMap(NetworkClientSocket *ignore_cs = nullptr);
+
 	NetworkRecvStatus SendMap();
 	NetworkRecvStatus SendErrorQuit(ClientID client_id, NetworkErrorCode errorno);
 	NetworkRecvStatus SendQuit(ClientID client_id);