From b41739146e8c3d8ba30d496e0aed70582ca2eba5 Mon Sep 17 00:00:00 2001
From: Quentin Bazin <quent42340@gmail.com>
Date: Sun, 23 May 2021 02:43:18 +0200
Subject: [PATCH] Fixed server crash when two players tried to connect with
 same name.

---
 source/server/network/Server.cpp              | 32 +++++++++----------
 source/server/network/Server.hpp              |  3 +-
 .../server/network/ServerCommandHandler.cpp   | 17 +++++++---
 .../server/network/ServerCommandHandler.hpp   |  2 +-
 4 files changed, 30 insertions(+), 24 deletions(-)

diff --git a/source/server/network/Server.cpp b/source/server/network/Server.cpp
index 31cc832cc..ca3b56040 100644
--- a/source/server/network/Server.cpp
+++ b/source/server/network/Server.cpp
@@ -43,6 +43,22 @@ void Server::disconnectAllClients() {
 		disconnectClient(it);
 }
 
+void Server::disconnectClient(ClientInfo &client) {
+	Network::Packet packet;
+	packet << Network::Command::ClientDisconnect << client.id;
+	sendToAllClients(packet);
+
+	m_commands[Network::Command::ClientDisconnect](client, packet);
+
+	m_selector.remove(*client.tcpSocket);
+	m_info.removeClient(client.id);
+
+	if (m_isSingleplayer && m_info.clients().size() == 0) {
+		m_tcpListener.close();
+		m_isRunning = false;
+	}
+}
+
 void Server::handleGameEvents() {
 	if (m_selector.wait(sf::milliseconds(10))) {
 		if (m_selector.isReady(m_tcpListener)) {
@@ -121,22 +137,6 @@ void Server::handleClientMessages() {
 	}
 }
 
-void Server::disconnectClient(ClientInfo &client) {
-	Network::Packet packet;
-	packet << Network::Command::ClientDisconnect << client.id;
-	sendToAllClients(packet);
-
-	m_commands[Network::Command::ClientDisconnect](client, packet);
-
-	m_selector.remove(*client.tcpSocket);
-	m_info.removeClient(client.id);
-
-	if (m_isSingleplayer && m_info.clients().size() == 0) {
-		m_tcpListener.close();
-		m_isRunning = false;
-	}
-}
-
 void Server::sendToAllClients(Network::Packet &packet) const {
 	for (const ClientInfo &client : m_info.clients()) {
 		client.tcpSocket->send(packet);
diff --git a/source/server/network/Server.hpp b/source/server/network/Server.hpp
index 6113e9c4d..36fa26069 100644
--- a/source/server/network/Server.hpp
+++ b/source/server/network/Server.hpp
@@ -44,6 +44,7 @@ class Server {
 		void init(u16 port = 4242);
 
 		void disconnectAllClients();
+		void disconnectClient(ClientInfo &client);
 
 		void handleGameEvents();
 
@@ -66,8 +67,6 @@ class Server {
 		void handleNewConnections();
 		void handleClientMessages();
 
-		void disconnectClient(ClientInfo &client);
-
 		bool m_isRunning = false;
 		bool m_isSingleplayer = false;
 
diff --git a/source/server/network/ServerCommandHandler.cpp b/source/server/network/ServerCommandHandler.cpp
index e3b9e9918..0768907f8 100644
--- a/source/server/network/ServerCommandHandler.cpp
+++ b/source/server/network/ServerCommandHandler.cpp
@@ -48,14 +48,18 @@ void ServerCommandHandler::sendServerTick(const ClientInfo *client) const {
 		client->tcpSocket->send(packet);
 }
 
-void ServerCommandHandler::sendServerClosed(const std::string &message, const ClientInfo *client) const {
+void ServerCommandHandler::sendServerClosed(const std::string &message, ClientInfo *client) const {
 	Network::Packet packet;
 	packet << Network::Command::ServerClosed << message;
 
-	if (!client)
+	if (!client) {
 		m_server.sendToAllClients(packet);
-	else
+		m_server.disconnectAllClients();
+	}
+	else {
 		client->tcpSocket->send(packet);
+		m_server.disconnectClient(*client);
+	}
 }
 
 void ServerCommandHandler::sendChunkUnload(s32 chunkX, s32 chunkY, s32 chunkZ, const ClientInfo *client) const {
@@ -294,8 +298,11 @@ void ServerCommandHandler::setupCallbacks() {
 	});
 
 	m_server.setCommandCallback(Network::Command::ClientDisconnect, [this](ClientInfo &client, Network::Packet &) {
-		m_players.getPlayerFromClientID(client.id)->clearLoadedChunks();
-		m_players.disconnectPlayer(client.playerName);
+		ServerPlayer *player = m_players.getPlayerFromClientID(client.id);
+		if (player) {
+			player->clearLoadedChunks();
+			m_players.disconnectPlayer(client.playerName);
+		}
 	});
 
 	m_server.setCommandCallback(Network::Command::ChunkUnload, [this](ClientInfo &client, Network::Packet &packet) {
diff --git a/source/server/network/ServerCommandHandler.hpp b/source/server/network/ServerCommandHandler.hpp
index d5ed4c8ec..adf240618 100644
--- a/source/server/network/ServerCommandHandler.hpp
+++ b/source/server/network/ServerCommandHandler.hpp
@@ -62,7 +62,7 @@ class ServerCommandHandler {
 			: m_scriptEngine(scriptEngine), m_server(server), m_worldController(worldController), m_players(players), m_registry(registry) {}
 
 		void sendServerTick(const ClientInfo *client = nullptr) const;
-		void sendServerClosed(const std::string &message, const ClientInfo *client = nullptr) const;
+		void sendServerClosed(const std::string &message, ClientInfo *client = nullptr) const;
 		void sendChunkUnload(s32 chunkX, s32 chunkY, s32 chunkZ, const ClientInfo *client = nullptr) const;
 		void sendBlockDataUpdate(s32 x, s32 y, s32 z, const BlockData *blockData, const ClientInfo *client = nullptr) const;
 		void sendBlockInvUpdate(s32 x, s32 y, s32 z, const Inventory &inventory, const ClientInfo *client = nullptr) const;