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.

/*
 * Here we are going to implement a function for serial input with a timeout.
 */

#include <stdlib.h>

serial_in_timeout(count)
	unsigned count;
{
	int c;

	do
		c = serial_in_poll();
	while (c < 0 && --count);
	return c;
}

void
cmd_sertimeout(argbulk)
	char *argbulk;
{
	char *argv[2];
	int count;

	if (parse_args(argbulk, 1, 1, argv, 0) < 0)
		return;
	count = atoi(argv[0]);
	serial_in_timeout(count);
}