From 69204aec07fb1e03fd6bf976d1d6511a691fbc86 Mon Sep 17 00:00:00 2001
From: Alibek Omarov <a1ba.omarov@gmail.com>
Date: Sun, 28 Sep 2025 22:31:46 +0500
Subject: [PATCH] engine: client: synchronize sv_cheats state with the server

---
 engine/client/cl_main.c     | 46 +++++++++++++++++++++++++------------
 engine/client/cl_parse.c    |  4 ++++
 engine/client/cl_parse_gs.c | 11 ++-------
 engine/client/client.h      |  5 ++++
 4 files changed, 42 insertions(+), 24 deletions(-)

diff --git a/engine/client/cl_main.c b/engine/client/cl_main.c
index fac7ff7c..1ec33bc6 100644
--- a/engine/client/cl_main.c
+++ b/engine/client/cl_main.c
@@ -174,6 +174,22 @@ connprotocol_t CL_Protocol( void )
 	return cls.legacymode;
 }
 
+void CL_SetCheatState( qboolean multiplayer, qboolean allow_cheats )
+{
+	if( NET_NetadrType( &cls.netchan.remote_address ) == NA_LOOPBACK )
+		return;
+
+	if( allow_cheats )
+	{
+		Cvar_FullSet( "sv_cheats", "1", FCVAR_READ_ONLY | FCVAR_SERVER );
+	}
+	else
+	{
+		Cvar_FullSet( "sv_cheats", "0", FCVAR_READ_ONLY | FCVAR_SERVER );
+		Cvar_SetCheatState();
+	}
+}
+
 /*
 ===============
 CL_CheckClientState
@@ -1072,13 +1088,9 @@ static void CL_SendConnectPacket( connprotocol_t proto, int challenge )
 	input_devices = IN_CollectInputDevices();
 	IN_LockInputDevices( adrtype != NA_LOOPBACK ? true : false );
 
-	// GoldSrc doesn't need sv_cheats set to 0, it's handled by svc_goldsrc_sendextrainfo
-	// it also doesn't need useragent string
+	// GoldSrc doesn't need useragent string
 	if( adrtype != NA_LOOPBACK && proto != PROTO_GOLDSRC )
 	{
-		Cvar_SetCheatState();
-		Cvar_FullSet( "sv_cheats", "0", FCVAR_READ_ONLY | FCVAR_SERVER );
-
 		Info_SetValueForKeyf( protinfo, "d", sizeof( protinfo ),  "%d", input_devices );
 		Info_SetValueForKey( protinfo, "v", XASH_VERSION, sizeof( protinfo ) );
 		Info_SetValueForKeyf( protinfo, "b", sizeof( protinfo ), "%d", Q_buildnum( ));
@@ -2338,16 +2350,24 @@ static void CL_ClientConnect( connprotocol_t proto, const char *c, netadr_t from
 		if( Q_strcmp( c, S2C_GOLDSRC_CONNECTION ))
 		{
 			Con_DPrintf( S_ERROR "GoldSrc client connect expected but wasn't received, ignored\n");
+			CL_Disconnect_f();
 			return;
 		}
 
-		if( Cmd_Argc() > 4 )
-			cls.build_num = Q_atoi( Cmd_Argv( 4 ));
+		cls.build_num = Q_atoi( Cmd_Argv( 4 ));
+		cls.allow_cheats = false; // set by svc_goldsrc_sendextrainfo
 	}
-	else if( !Q_strcmp( c, S2C_GOLDSRC_CONNECTION ))
+	else
 	{
-		Con_DPrintf( S_ERROR "GoldSrc client connect received but wasn't expected, ignored\n");
-		return;
+		if( Q_strcmp( c, S2C_CONNECTION ))
+		{
+			Con_DPrintf( S_ERROR "Xash3D client connect expected but wasn't received, ignored\n");
+			CL_Disconnect_f();
+			return;
+		}
+
+		cls.build_num = 0; // not used in Xash3D protocols
+		cls.allow_cheats = Q_atoi( Info_ValueForKey( Cmd_Argv( 1 ), "cheats" ));
 	}
 
 	CL_Reconnect( true );
@@ -2753,11 +2773,7 @@ static void CL_ReadPackets( void )
 	CL_ReadNetMessage();
 
 	CL_ApplyAddAngle();
-#if 0
-	// keep cheat cvars are unchanged
-	if( cl.maxclients > 1 && cls.state == ca_active && !host_developer.value )
-		Cvar_SetCheatState();
-#endif
+
 	// hot precache and downloading resources
 	if( cls.signon == SIGNONS && cl.lastresourcecheck < host.realtime )
 	{
diff --git a/engine/client/cl_parse.c b/engine/client/cl_parse.c
index 1997dd93..755cf1ac 100644
--- a/engine/client/cl_parse.c
+++ b/engine/client/cl_parse.c
@@ -1003,6 +1003,10 @@ void CL_ParseServerData( sizebuf_t *msg, connprotocol_t proto )
 	}
 	else Cvar_DirectSet( &r_decals, NULL );
 
+	// for GoldSrc, it's handled by svc_goldsrc_sendextrainfo
+	if( proto != PROTO_GOLDSRC )
+		CL_SetCheatState( cl.maxclients > 1, cls.allow_cheats );
+
 	// set the background state
 	if( cls.demoplayback && ( cls.demonum != -1 ))
 		cl.background = true;
diff --git a/engine/client/cl_parse_gs.c b/engine/client/cl_parse_gs.c
index 5bfce813..4d9903ae 100644
--- a/engine/client/cl_parse_gs.c
+++ b/engine/client/cl_parse_gs.c
@@ -31,15 +31,8 @@ static void CL_ParseExtraInfo( sizebuf_t *msg )
 	if( COM_CheckStringEmpty( clientfallback ))
 		Con_Reportf( S_ERROR "%s: TODO: add fallback directory %s!\n", __func__, clientfallback );
 
-	if( MSG_ReadByte( msg ))
-	{
-		Cvar_FullSet( "sv_cheats", "1", FCVAR_READ_ONLY | FCVAR_SERVER );
-	}
-	else
-	{
-		Cvar_SetCheatState();
-		Cvar_FullSet( "sv_cheats", "0", FCVAR_READ_ONLY | FCVAR_SERVER );
-	}
+	cls.allow_cheats = MSG_ReadByte( msg ) ? true : false;
+	CL_SetCheatState( cl.maxclients > 1, cls.allow_cheats );
 }
 
 static void CL_ParseNewMovevars( sizebuf_t *msg )
diff --git a/engine/client/client.h b/engine/client/client.h
index 4ba3a969..5750aea4 100644
--- a/engine/client/client.h
+++ b/engine/client/client.h
@@ -640,6 +640,10 @@ typedef struct
 	// server's build number (might be zero)
 	int build_num;
 	uint8_t steamid[8];
+
+	// whether server allows cheats or not
+	// set differently depending on protocol and extensions
+	qboolean allow_cheats;
 } client_static_t;
 
 #ifdef __cplusplus
@@ -763,6 +767,7 @@ void CL_UpdateFrameLerp( void );
 int CL_IsDevOverviewMode( void );
 void CL_SignonReply( connprotocol_t proto );
 void CL_ClearState( void );
+void CL_SetCheatState( qboolean multiplayer, qboolean allow_cheats );
 
 //
 // cl_demo.c