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 header file defines the data structures for the SREC reader module */

struct srecreader {
	char		*filename;
	FILE		*openfile;
	int		lineno;
	u_char		record[256];	/* binary */
	char		record_type;	/* ASCII char */
	u_char		datalen;
	uint32_t	addr;
};