engine: client: add command replaybufferdat to aid in debugging protocol errors by parsing buffer.dat

engine/client/cl_debug.c

@@ -198,3 +198,44 @@ void CL_WriteMessageHistory( void )
 	CL_WriteErrorMessage( old->starting_offset, msg );
 	cls_message_debug.parsing = false;
 }
+
+void CL_ReplayBufferDat_f( void )
+{
+	file_t *f = FS_Open( Cmd_Argv( 1 ), "rb", true );
+	sizebuf_t msg;
+	char buffer[NET_MAX_MESSAGE];
+	int starting_count, current_count, protocol;
+	fs_offset_t len;
+
+	if( !f )
+		return;
+
+	FS_Read( f, &starting_count, sizeof( starting_count ));
+	FS_Read( f, &current_count, sizeof( current_count ));
+	FS_Read( f, &protocol, sizeof( protocol ));
+
+	cls.legacymode = protocol;
+
+	len = FS_Read( f, buffer, sizeof( buffer ));
+	FS_Close( f );
+
+	MSG_Init( &msg, __func__, buffer, len );
+
+	Delta_Shutdown();
+	Delta_Init();
+
+	clgame.maxEntities = MAX_EDICTS;
+	clgame.entities = Mem_Calloc( clgame.mempool, sizeof( *clgame.entities ) * clgame.maxEntities );
+
+	// ad-hoc implement
+#if 0
+	{
+		const int message_pos = 12; // put real number here
+		MSG_SeekToBit( &msg, ( message_pos - 12 + 1 ) << 3, SEEK_SET );
+
+		CL_ParseYourMom( &msg, protocol );
+	}
+#endif
+
+	Sys_Quit( __func__ );
+}

engine/client/cl_main.c

@@ -3489,6 +3489,8 @@ static void CL_InitLocal( void )
 	Cmd_AddCommand ("fullserverinfo", CL_FullServerinfo_f, "sent by server when serverinfo changes" );
 	Cmd_AddCommand ("upload", CL_BeginUpload_f, "uploading file to the server" );
 
+	Cmd_AddRestrictedCommand( "replaybufferdat", CL_ReplayBufferDat_f, "development and debugging tool" );
+
 	Cmd_AddRestrictedCommand ("quit", CL_Quit_f, "quit from game" );
 	Cmd_AddRestrictedCommand ("exit", CL_Quit_f, "quit from game" );
 

engine/client/client.h

@@ -737,6 +737,7 @@ void CL_ClearResourceLists( void );
 //
 // cl_debug.c
 //
+void CL_ReplayBufferDat_f( void );
 void CL_Parse_Debug( qboolean enable );
 void CL_Parse_RecordCommand( int cmd, int startoffset );
 void CL_ResetFrame( frame_t *frame );