Fix: [Network] clients leaving because of broken connections was not broadcasted (#9238)

The code mixed up "client has quit but we already told everyone"
with "client lost connection, handle this".

Split up those two signals:
- CLIENT_QUIT means we told everyone and the connection is now dead
- CONNECTION_LIST means we should tell everyone we lost a client

6 files changed, 25 insertions, 24 deletions

diff --git a/src/network/core/core.h b/src/network/core/core.h
index aac36080f..37948ad52 100644
--- a/src/network/core/core.h
+++ b/src/network/core/core.h
@@ -20,16 +20,17 @@ void NetworkCoreShutdown();
 
 /** Status of a network client; reasons why a client has quit */
 enum NetworkRecvStatus {
-	NETWORK_RECV_STATUS_OKAY,             ///< Everything is okay
-	NETWORK_RECV_STATUS_DESYNC,           ///< A desync did occur
-	NETWORK_RECV_STATUS_NEWGRF_MISMATCH,  ///< We did not have the required NewGRFs
-	NETWORK_RECV_STATUS_SAVEGAME,         ///< Something went wrong (down)loading the savegame
-	NETWORK_RECV_STATUS_CONN_LOST,        ///< The connection is 'just' lost
-	NETWORK_RECV_STATUS_MALFORMED_PACKET, ///< We apparently send a malformed packet
-	NETWORK_RECV_STATUS_SERVER_ERROR,     ///< The server told us we made an error
-	NETWORK_RECV_STATUS_SERVER_FULL,      ///< The server is full
-	NETWORK_RECV_STATUS_SERVER_BANNED,    ///< The server has banned us
-	NETWORK_RECV_STATUS_CLOSE_QUERY,      ///< Done querying the server
+	NETWORK_RECV_STATUS_OKAY,             ///< Everything is okay.
+	NETWORK_RECV_STATUS_DESYNC,           ///< A desync did occur.
+	NETWORK_RECV_STATUS_NEWGRF_MISMATCH,  ///< We did not have the required NewGRFs.
+	NETWORK_RECV_STATUS_SAVEGAME,         ///< Something went wrong (down)loading the savegame.
+	NETWORK_RECV_STATUS_CLIENT_QUIT,      ///< The connection is lost gracefully. Other clients are already informed of this leaving client.
+	NETWORK_RECV_STATUS_MALFORMED_PACKET, ///< We apparently send a malformed packet.
+	NETWORK_RECV_STATUS_SERVER_ERROR,     ///< The server told us we made an error.
+	NETWORK_RECV_STATUS_SERVER_FULL,      ///< The server is full.
+	NETWORK_RECV_STATUS_SERVER_BANNED,    ///< The server has banned us.
+	NETWORK_RECV_STATUS_CLOSE_QUERY,      ///< Done querying the server.
+	NETWORK_RECV_STATUS_CONNECTION_LOST,  ///< The connection is lost unexpectedly.
 };
 
 /** Forward declaration due to circular dependencies */
diff --git a/src/network/core/tcp_admin.cpp b/src/network/core/tcp_admin.cpp
index c72583f55..36daae4a1 100644
--- a/src/network/core/tcp_admin.cpp
+++ b/src/network/core/tcp_admin.cpp
@@ -41,7 +41,7 @@ NetworkAdminSocketHandler::~NetworkAdminSocketHandler()
 NetworkRecvStatus NetworkAdminSocketHandler::CloseConnection(bool error)
 {
 	delete this;
-	return NETWORK_RECV_STATUS_CONN_LOST;
+	return NETWORK_RECV_STATUS_CLIENT_QUIT;
 }
 
 /**
diff --git a/src/network/core/tcp_game.cpp b/src/network/core/tcp_game.cpp
index eb53db5ac..771ea37b1 100644
--- a/src/network/core/tcp_game.cpp
+++ b/src/network/core/tcp_game.cpp
@@ -48,10 +48,10 @@ NetworkRecvStatus NetworkGameSocketHandler::CloseConnection(bool error)
 		_networking = false;
 		ShowErrorMessage(STR_NETWORK_ERROR_LOSTCONNECTION, INVALID_STRING_ID, WL_CRITICAL);
 
-		return NETWORK_RECV_STATUS_CONN_LOST;
+		return NETWORK_RECV_STATUS_CLIENT_QUIT;
 	}
 
-	return this->CloseConnection(error ? NETWORK_RECV_STATUS_SERVER_ERROR : NETWORK_RECV_STATUS_CONN_LOST);
+	return this->CloseConnection(NETWORK_RECV_STATUS_CONNECTION_LOST);
 }
 
 
diff --git a/src/network/network.cpp b/src/network/network.cpp
index 4fdbdab73..2186cb8a1 100644
--- a/src/network/network.cpp
+++ b/src/network/network.cpp
@@ -585,13 +585,13 @@ void NetworkClose(bool close_admins)
 		}
 
 		for (NetworkClientSocket *cs : NetworkClientSocket::Iterate()) {
-			cs->CloseConnection(NETWORK_RECV_STATUS_CONN_LOST);
+			cs->CloseConnection(NETWORK_RECV_STATUS_CLIENT_QUIT);
 		}
 		ServerNetworkGameSocketHandler::CloseListeners();
 		ServerNetworkAdminSocketHandler::CloseListeners();
 	} else if (MyClient::my_client != nullptr) {
 		MyClient::SendQuit();
-		MyClient::my_client->CloseConnection(NETWORK_RECV_STATUS_CONN_LOST);
+		MyClient::my_client->CloseConnection(NETWORK_RECV_STATUS_CLIENT_QUIT);
 	}
 
 	TCPConnecter::KillAll();
diff --git a/src/network/network_client.cpp b/src/network/network_client.cpp
index f827c5735..501449705 100644
--- a/src/network/network_client.cpp
+++ b/src/network/network_client.cpp
@@ -656,7 +656,7 @@ NetworkRecvStatus ClientNetworkGameSocketHandler::Receive_SERVER_CLIENT_INFO(Pac
 	p->Recv_string(name, sizeof(name));
 
 	if (this->status < STATUS_AUTHORIZED) return NETWORK_RECV_STATUS_MALFORMED_PACKET;
-	if (this->HasClientQuit()) return NETWORK_RECV_STATUS_CONN_LOST;
+	if (this->HasClientQuit()) return NETWORK_RECV_STATUS_CLIENT_QUIT;
 	/* The server validates the name when receiving it from clients, so when it is wrong
 	 * here something went really wrong. In the best case the packet got malformed on its
 	 * way too us, in the worst case the server is broken or compromised. */
diff --git a/src/network/network_server.cpp b/src/network/network_server.cpp
index e8266a84f..eccf80f78 100644
--- a/src/network/network_server.cpp
+++ b/src/network/network_server.cpp
@@ -256,7 +256,7 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::CloseConnection(NetworkRecvSta
 	 */
 	if (this->sock == INVALID_SOCKET) return status;
 
-	if (status != NETWORK_RECV_STATUS_CONN_LOST && status != NETWORK_RECV_STATUS_SERVER_ERROR && !this->HasClientQuit() && this->status >= STATUS_AUTHORIZED) {
+	if (status != NETWORK_RECV_STATUS_CLIENT_QUIT && status != NETWORK_RECV_STATUS_SERVER_ERROR && !this->HasClientQuit() && this->status >= STATUS_AUTHORIZED) {
 		/* We did not receive a leave message from this client... */
 		char client_name[NETWORK_CLIENT_NAME_LENGTH];
 
@@ -893,7 +893,7 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_JOIN(Packet *p)
 	p->Recv_string(name, sizeof(name));
 	playas = (Owner)p->Recv_uint8();
 
-	if (this->HasClientQuit()) return NETWORK_RECV_STATUS_CONN_LOST;
+	if (this->HasClientQuit()) return NETWORK_RECV_STATUS_CLIENT_QUIT;
 
 	/* join another company does not affect these values */
 	switch (playas) {
@@ -1077,7 +1077,7 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_COMMAND(Packet
 	CommandPacket cp;
 	const char *err = this->ReceiveCommand(p, &cp);
 
-	if (this->HasClientQuit()) return NETWORK_RECV_STATUS_CONN_LOST;
+	if (this->HasClientQuit()) return NETWORK_RECV_STATUS_CLIENT_QUIT;
 
 	NetworkClientInfo *ci = this->GetInfo();
 
@@ -1136,7 +1136,7 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_ERROR(Packet *p
 
 	/* The client was never joined.. thank the client for the packet, but ignore it */
 	if (this->status < STATUS_DONE_MAP || this->HasClientQuit()) {
-		return this->CloseConnection(NETWORK_RECV_STATUS_CONN_LOST);
+		return this->CloseConnection(NETWORK_RECV_STATUS_CLIENT_QUIT);
 	}
 
 	this->GetClientName(client_name, lastof(client_name));
@@ -1156,7 +1156,7 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_ERROR(Packet *p
 
 	NetworkAdminClientError(this->client_id, errorno);
 
-	return this->CloseConnection(NETWORK_RECV_STATUS_CONN_LOST);
+	return this->CloseConnection(NETWORK_RECV_STATUS_CLIENT_QUIT);
 }
 
 NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_QUIT(Packet *p)
@@ -1167,7 +1167,7 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_QUIT(Packet *p)
 
 	/* The client was never joined.. thank the client for the packet, but ignore it */
 	if (this->status < STATUS_DONE_MAP || this->HasClientQuit()) {
-		return this->CloseConnection(NETWORK_RECV_STATUS_CONN_LOST);
+		return this->CloseConnection(NETWORK_RECV_STATUS_CLIENT_QUIT);
 	}
 
 	this->GetClientName(client_name, lastof(client_name));
@@ -1182,7 +1182,7 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_QUIT(Packet *p)
 
 	NetworkAdminClientQuit(this->client_id);
 
-	return this->CloseConnection(NETWORK_RECV_STATUS_CONN_LOST);
+	return this->CloseConnection(NETWORK_RECV_STATUS_CLIENT_QUIT);
 }
 
 NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_ACK(Packet *p)
@@ -1412,7 +1412,7 @@ NetworkRecvStatus ServerNetworkGameSocketHandler::Receive_CLIENT_SET_NAME(Packet
 	p->Recv_string(client_name, sizeof(client_name));
 	ci = this->GetInfo();
 
-	if (this->HasClientQuit()) return NETWORK_RECV_STATUS_CONN_LOST;
+	if (this->HasClientQuit()) return NETWORK_RECV_STATUS_CLIENT_QUIT;
 
 	if (ci != nullptr) {
 		if (!NetworkIsValidClientName(client_name)) {