From 20baf8e39074313cc3620d99e3cd099d87d933dc Mon Sep 17 00:00:00 2001
From: Knightmare66 <knightmare66@yahoo.com>
Date: Thu, 18 Mar 2021 05:35:26 -0400
Subject: [PATCH] Added handling for "print" command in
 cl_main.c->CL_ConnectionlessPacket() that changes cl_servertrick and
 reconnects when a known "wrong version" rejection message is received.
 Changed wrong protocol rejection messaged in sv_main.c->SVC_DirectConnect()
 to send KMQuake2 version instead of just version number.

---
 client/cl_main.c       | 27 +++++++++++++++++++++++++++
 kmquake2.txt           |  2 +-
 kmquake2_changelog.txt |  2 ++
 server/sv_main.c       |  3 ++-
 4 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/client/cl_main.c b/client/cl_main.c
index 1887ccd..d4c99cd 100644
--- a/client/cl_main.c
+++ b/client/cl_main.c
@@ -1569,11 +1569,38 @@ void CL_ConnectionlessPacket (void)
 		Cbuf_AddText ("\n");
 		return;
 	}
+
 	// print command from somewhere
 	if (!strcmp(c, "print"))
 	{
+		char	thisVersionRejMsg[64];
+
 		s = MSG_ReadString (&net_message);
 		Com_Printf ("%s", s);
+
+		// catch wrong version reply from server here
+		Com_sprintf (thisVersionRejMsg, sizeof(thisVersionRejMsg), "You need KMQuake2 version %4.2f to play on this server.", VERSION);
+		if ( strstr(s, "Server is version 3.19") || strstr(s, "Server is version 3.2")	// stock Q2 3.19 / 3.2x rejection messages
+			|| strstr(s, "You need Quake II 3.19 or higher to play on this server.")	// R1Q2
+			|| strstr(s, "Unsupported protocol version") || strstr(s, "You need Quake 2 version 3.19 or higher.") )	// Q2Pro
+		{
+			Cvar_SetInteger ("cl_servertrick", 1);
+			Com_Printf ("Wrong version reply received from server.  Reconnecting as protocol version %i.\n", OLD_PROTOCOL_VERSION);
+			CL_Reconnect_f ();
+		}
+		else if ( strstr(s, thisVersionRejMsg) )	// Same version of KMQ2
+		{
+			Cvar_SetInteger ("cl_servertrick", 0);
+			Com_Printf ("Wrong version reply received from server.  Reconnecting as protocol version %i.\n", PROTOCOL_VERSION);
+			CL_Reconnect_f ();
+		}
+		else if ( strstr(s, "Server is version") )	// don't keep going if unknown version
+		{
+			Com_Printf ("Unknown wrong version reply received from server.  Disconnecting.\n");
+			SCR_EndLoadingPlaque ();
+			CL_Disconnect ();
+		}
+
 		return;
 	}
 
diff --git a/kmquake2.txt b/kmquake2.txt
index 3692f72..bb56b6b 100644
--- a/kmquake2.txt
+++ b/kmquake2.txt
@@ -113,7 +113,7 @@ How To Run
 	mod's code to run, it must be compiled into a kmq2gamex86.dll (see end of file for
 	instructions).
 
-	To connect to standard Quake2 (protocol 34) servers, add
+	To ping info from and connect to standard Quake2 (protocol 34) servers, add
 	
 	+set cl_servertrick 1
 	
diff --git a/kmquake2_changelog.txt b/kmquake2_changelog.txt
index 5c2143a..57f96e1 100644
--- a/kmquake2_changelog.txt
+++ b/kmquake2_changelog.txt
@@ -21,6 +21,8 @@ Changes as of v0.20 update 8:
 
 - Added support for quake2:// URLs.
 
+- Added client auto-reconnect with cl_servertrick set correspondingly when a known "wrong version" rejection message is received.
+
 - Added cel shading support.  Uses cvars r_celshading to enable, and r_celshading_width for line width (1-10).
 
 - Added horizontal offset to third-person mode.  Offset distance is controlled by cvar cg_thirdperson_offset.
diff --git a/server/sv_main.c b/server/sv_main.c
index f18bc59..b1ef288 100644
--- a/server/sv_main.c
+++ b/server/sv_main.c
@@ -399,7 +399,8 @@ void SVC_DirectConnect (void)
 	version = atoi(Cmd_Argv(1));
 	if (version != PROTOCOL_VERSION)
 	{
-		Netchan_OutOfBandPrint (NS_SERVER, adr, "print\nServer is version %4.2f.\n", VERSION);
+	//	Netchan_OutOfBandPrint (NS_SERVER, adr, "print\nServer is version %4.2f.\n", VERSION);
+		Netchan_OutOfBandPrint (NS_SERVER, adr, "print\nYou need KMQuake2 version %4.2f to play on this server.\n", VERSION);
 		Com_DPrintf ("    rejected connect from version %i\n", version);
 		return;
 	}