rem: remote_version = read_int(f_in); write_int(f_out,PROTOCOL_VERSION);
add: remote_protocol = read_int(f_in); write_int(f_out, protocol_version);
context: void setup_protocol(int f_out,int f_in){	if (remote_version == 0) {		if (am_server) {			remote_version = read_int(f_in);			write_int(f_out,PROTOCOL_VERSION);		} else {			write_int(f_out,PROTOCOL_VERSION);			remote_version = read_int(f_in);		}	}	if (remote_version < MIN_PROTOCOL_VERSION ||	    remote_version > MAX_PROTOCOL_VERSION) {		rprintf(FERROR,"protocol version mismatch - is your shell clean?\n");		rprintf(FERROR,"(see the rsync man page for an explanation)\n");		exit_cleanup(RERR_PROTOCOL);	}		if (remote_version < OLD_PROTOCOL_VERSION)		rprintf(FINFO,"%s is very old version of rsync, upgrade recommended.\n",			am_server ? "Server" : "Client");	if (am_server) {		if (read_batch || write_batch) /* dw */			checksum_seed = 32761;		else			checksum_seed = time(NULL);		write_int(f_out,checksum_seed);	} else {		checksum_seed = read_int(f_in);	}}