Function writezone

zic.c:2660–3086

  return r;
}

static void
writezone(const char *const name, const char *const string, char version,
	  int defaulttype)
{
	register FILE *			fp;
	register ptrdiff_t		i, j;
	register int			pass;
	char *tempname = NULL;
	char const *outname = name;

	/* Allocate the ATS and TYPES arrays via a single malloc,
	   as this is a bit faster.  Do not malloc(0) if !timecnt,
	   as that might return NULL even on success.  */
	zic_t *ats = xmalloc(align_to(size_product(timecnt + !timecnt,
						   sizeof *ats + 1),
				      alignof(zic_t)));
	void *typesptr = ats + timecnt;
	unsigned char *types = typesptr;
	struct timerange rangeall = {0}, range32, range64;

	/*
	** Sort.
	*/
	if (timecnt > 1)
		qsort(attypes, timecnt, sizeof *attypes, atcomp);
	/*
	** Optimize and skip unwanted transitions.
	*/
	{
		ptrdiff_t fromi, toi;

		toi = 0;
		fromi = 0;
		for ( ; fromi < timecnt; ++fromi) {
			if (toi != 0) {
			    /* Skip the previous transition if it is unwanted
			       because its local time is not earlier.
			       The UT offset additions can't overflow because
			       of how the times were calculated.  */
			    unsigned char type_2 =
			      toi == 1 ? 0 : attypes[toi - 2].type;
			    if ((attypes[fromi].at
				 + utoffs[attypes[toi - 1].type])
				<= attypes[toi - 1].at + utoffs[type_2]) {
				    if (attypes[fromi].type == type_2)
					toi--;
				    else
					attypes[toi - 1].type =
						attypes[fromi].type;
				    continue;
			    }
			}

			/* Use a transition if it is the first one,
			   or if it cannot be merged for other reasons,
			   or if it transitions to different timekeeping.  */