fcup-smsend[mult]: fix buglet in K&R C NULL pointer passing The only 100% safe way to pass a NULL pointer as a function argument in K&R C is to cast 0 to a pointer type; failing to do so may cause mysterious bugs (invalid stack frames or garbage in argument registers) on 64-bit machines. This issue has already been fixed in most of FC host tools, but I just found some missed spots: passing of NULL UDH to PDU encoding functions in fcup-smsend[mult] in the case of single (not concatenated) SMS.

/*
 * This module implements the basic serial port opening operation.
 */

#include <sys/types.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

int target_fd;

open_serial_port(ttyport)
	char *ttyport;
{
	target_fd = open(ttyport, O_RDWR|O_NONBLOCK);
	if (target_fd < 0) {
		perror(ttyport);
		exit(1);
	}
	ioctl(target_fd, TIOCEXCL);
	return 0;
}