From 1380bf9b88521ccd57d510abe51c7eef68919b92 Mon Sep 17 00:00:00 2001
From: sfan5 <sfan5@live.de>
Date: Wed, 21 Aug 2024 22:13:03 +0200
Subject: [PATCH] Fix ordering issue with new server peers

---
 src/client/client.cpp     |  2 ++
 src/network/peerhandler.h | 21 ++------------------
 src/server.cpp            | 41 +++++----------------------------------
 src/server.h              |  7 -------
 4 files changed, 9 insertions(+), 62 deletions(-)

diff --git a/src/client/client.cpp b/src/client/client.cpp
index d07a8eb4a..9c12be8f2 100644
--- a/src/client/client.cpp
+++ b/src/client/client.cpp
@@ -436,6 +436,8 @@ void Client::step(float dtime)
 		}
 	}
 
+	// The issue that made this workaround necessary was fixed in August 2024, but
+	// it's not like we can remove this code - ever.
 	if (m_state == LC_Created) {
 		float &counter = m_connection_reinit_timer;
 		counter -= dtime;
diff --git a/src/network/peerhandler.h b/src/network/peerhandler.h
index 1e00249ca..64e2c85fb 100644
--- a/src/network/peerhandler.h
+++ b/src/network/peerhandler.h
@@ -30,9 +30,10 @@ class PeerHandler
 {
 public:
 	PeerHandler() = default;
-
 	virtual ~PeerHandler() = default;
 
+	// Note: all functions are called from within a Receive() call on the same thread.
+
 	/*
 		This is called after the Peer has been inserted into the
 		Connection's peer container.
@@ -46,22 +47,4 @@ public:
 	virtual void deletingPeer(IPeer *peer, bool timeout) = 0;
 };
 
-enum PeerChangeType : u8
-{
-	PEER_ADDED,
-	PEER_REMOVED
-};
-
-struct PeerChange
-{
-	PeerChange(PeerChangeType t, session_t _peer_id, bool _timeout) :
-			type(t), peer_id(_peer_id), timeout(_timeout)
-	{
-	}
-	PeerChange() = delete;
-
-	PeerChangeType type;
-	session_t peer_id;
-	bool timeout;
-};
 }
diff --git a/src/server.cpp b/src/server.cpp
index fe831d0f7..609b7188b 100644
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -623,8 +623,6 @@ void Server::AsyncRunStep(float dtime, bool initial_step)
 	*/
 	m_uptime_counter->increment(dtime);
 
-	handlePeerChanges();
-
 	/*
 		Update time of day and overall game time
 	*/
@@ -1257,19 +1255,18 @@ void Server::onMapEditEvent(const MapEditEvent &event)
 
 void Server::peerAdded(con::IPeer *peer)
 {
-	verbosestream<<"Server::peerAdded(): peer->id="
-			<<peer->id<<std::endl;
+	verbosestream << "Server::peerAdded(): id=" << peer->id << std::endl;
 
-	m_peer_change_queue.push(con::PeerChange(con::PEER_ADDED, peer->id, false));
+	m_clients.CreateClient(peer->id);
 }
 
 void Server::deletingPeer(con::IPeer *peer, bool timeout)
 {
-	verbosestream<<"Server::deletingPeer(): peer->id="
-			<<peer->id<<", timeout="<<timeout<<std::endl;
+	verbosestream << "Server::deletingPeer(): id=" << peer->id
+		<< ", timeout=" << timeout << std::endl;
 
 	m_clients.event(peer->id, CSE_Disconnect);
-	m_peer_change_queue.push(con::PeerChange(con::PEER_REMOVED, peer->id, timeout));
+	DeleteClient(peer->id, timeout ? CDR_TIMEOUT : CDR_LEAVE);
 }
 
 bool Server::getClientConInfo(session_t peer_id, con::rtt_stat_type type, float* retval)
@@ -1313,34 +1310,6 @@ const ClientDynamicInfo *Server::getClientDynamicInfo(session_t peer_id)
 	return &client->getDynamicInfo();
 }
 
-void Server::handlePeerChanges()
-{
-	while(!m_peer_change_queue.empty())
-	{
-		con::PeerChange c = m_peer_change_queue.front();
-		m_peer_change_queue.pop();
-
-		verbosestream<<"Server: Handling peer change: "
-				<<"id="<<c.peer_id<<", timeout="<<c.timeout
-				<<std::endl;
-
-		switch(c.type)
-		{
-		case con::PEER_ADDED:
-			m_clients.CreateClient(c.peer_id);
-			break;
-
-		case con::PEER_REMOVED:
-			DeleteClient(c.peer_id, c.timeout?CDR_TIMEOUT:CDR_LEAVE);
-			break;
-
-		default:
-			FATAL_ERROR("Invalid peer change event received!");
-			break;
-		}
-	}
-}
-
 void Server::printToConsoleOnly(const std::string &text)
 {
 	if (m_admin_chat) {
diff --git a/src/server.h b/src/server.h
index 76c2dfc41..17eb9d769 100644
--- a/src/server.h
+++ b/src/server.h
@@ -673,13 +673,6 @@ private:
 	*/
 	ClientInterface m_clients;
 
-	/*
-		Peer change queue.
-		Queues stuff from peerAdded() and deletingPeer() to
-		handlePeerChanges()
-	*/
-	std::queue<con::PeerChange> m_peer_change_queue;
-
 	std::unordered_map<session_t, std::string> m_formspec_state_data;
 
 	/*