+ if (ttisp->tt_abbrind < 0 ||
+ ttisp->tt_abbrind > sp->charcnt)
+ return -1;
+ }
+ for (i = 0; i < sp->charcnt; ++i)
+ sp->chars[i] = *p++;
+ sp->chars[i] = '\0'; /* ensure '\0' at end */
+ for (i = 0; i < sp->leapcnt; ++i) {
+ register struct lsinfo * lsisp;
+
+ lsisp = &sp->lsis[i];
+ lsisp->ls_trans = detzcode(p);
+ p += 4;
+ lsisp->ls_corr = detzcode(p);
+ p += 4;
+ }
+ for (i = 0; i < sp->typecnt; ++i) {
+ register struct ttinfo * ttisp;
+
+ ttisp = &sp->ttis[i];
+ if (ttisstdcnt == 0)
+ ttisp->tt_ttisstd = FALSE;
+ else {
+ ttisp->tt_ttisstd = *p++;
+ if (ttisp->tt_ttisstd != TRUE &&
+ ttisp->tt_ttisstd != FALSE)
+ return -1;
+ }
+ }
+ }
+ return 0;
+}
+
+static const int mon_lengths[2][MONSPERYEAR] = {
+ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31,
+ 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
+};
+
+static const int year_lengths[2] = {
+ DAYSPERNYEAR, DAYSPERLYEAR
+};
+
+/*
+** Given a pointer into a time zone string, scan until a character that is not
+** a valid character in a zone name is found. Return a pointer to that
+** character.
+*/
+
+static const char *
+getzname(strp)
+register const char * strp;
+{
+ register char c;
+
+ while ((c = *strp) != '\0' && !isdigit(c) && c != ',' && c != '-' &&
+ c != '+')
+ ++strp;
+ return strp;
+}
+
+/*
+** Given a pointer into a time zone string, extract a number from that string.
+** Check that the number is within a specified range; if it is not, return
+** NULL.
+** Otherwise, return a pointer to the first character not part of the number.
+*/
+
+static const char *
+getnum(strp, nump, min, max)
+register const char * strp;
+int * const nump;
+const int min;
+const int max;
+{
+ register char c;
+ register int num;
+
+ if (strp == NULL || !isdigit(*strp))
+ return NULL;
+ num = 0;
+ while ((c = *strp) != '\0' && isdigit(c)) {
+ num = num * 10 + (c - '0');
+ if (num > max)
+ return NULL; /* illegal value */
+ ++strp;
+ }
+ if (num < min)
+ return NULL; /* illegal value */
+ *nump = num;
+ return strp;
+}
+
+/*
+** Given a pointer into a time zone string, extract a number of seconds,
+** in hh[:mm[:ss]] form, from the string.
+** If any error occurs, return NULL.
+** Otherwise, return a pointer to the first character not part of the number
+** of seconds.
+*/
+
+static const char *
+getsecs(strp, secsp)
+register const char * strp;
+long * const secsp;
+{
+ int num;
+
+ strp = getnum(strp, &num, 0, HOURSPERDAY);
+ if (strp == NULL)
+ return NULL;
+ *secsp = num * SECSPERHOUR;
+ if (*strp == ':') {
+ ++strp;
+ strp = getnum(strp, &num, 0, MINSPERHOUR - 1);
+ if (strp == NULL)
+ return NULL;
+ *secsp += num * SECSPERMIN;
+ if (*strp == ':') {
+ ++strp;
+ strp = getnum(strp, &num, 0, SECSPERMIN - 1);
+ if (strp == NULL)
+ return NULL;
+ *secsp += num;
+ }
+ }
+ return strp;
+}
+
+/*
+** Given a pointer into a time zone string, extract an offset, in
+** [+-]hh[:mm[:ss]] form, from the string.
+** If any error occurs, return NULL.
+** Otherwise, return a pointer to the first character not part of the time.
+*/
+
+static const char *
+getoffset(strp, offsetp)
+register const char * strp;
+long * const offsetp;
+{
+ register int neg;
+
+ if (*strp == '-') {
+ neg = 1;
+ ++strp;
+ } else if (isdigit(*strp) || *strp++ == '+')
+ neg = 0;
+ else return NULL; /* illegal offset */
+ strp = getsecs(strp, offsetp);
+ if (strp == NULL)
+ return NULL; /* illegal time */
+ if (neg)
+ *offsetp = -*offsetp;
+ return strp;
+}
+
+/*
+** Given a pointer into a time zone string, extract a rule in the form
+** date[/time]. See POSIX section 8 for the format of "date" and "time".
+** If a valid rule is not found, return NULL.
+** Otherwise, return a pointer to the first character not part of the rule.
+*/
+
+static const char *
+getrule(strp, rulep)
+const char * strp;
+register struct rule * const rulep;
+{
+ if (*strp == 'J') {
+ /*
+ ** Julian day.
+ */
+ rulep->r_type = JULIAN_DAY;
+ ++strp;
+ strp = getnum(strp, &rulep->r_day, 1, DAYSPERNYEAR);
+ } else if (*strp == 'M') {
+ /*
+ ** Month, week, day.
+ */
+ rulep->r_type = MONTH_NTH_DAY_OF_WEEK;
+ ++strp;
+ strp = getnum(strp, &rulep->r_mon, 1, MONSPERYEAR);
+ if (strp == NULL)
+ return NULL;
+ if (*strp++ != '.')
+ return NULL;
+ strp = getnum(strp, &rulep->r_week, 1, 5);
+ if (strp == NULL)
+ return NULL;
+ if (*strp++ != '.')
+ return NULL;
+ strp = getnum(strp, &rulep->r_day, 0, DAYSPERWEEK - 1);
+ } else if (isdigit(*strp)) {
+ /*
+ ** Day of year.
+ */
+ rulep->r_type = DAY_OF_YEAR;
+ strp = getnum(strp, &rulep->r_day, 0, DAYSPERLYEAR - 1);
+ } else return NULL; /* invalid format */
+ if (strp == NULL)
+ return NULL;
+ if (*strp == '/') {
+ /*
+ ** Time specified.
+ */
+ ++strp;
+ strp = getsecs(strp, &rulep->r_time);
+ } else rulep->r_time = 2 * SECSPERHOUR; /* default = 2:00:00 */
+ return strp;
+}
+
+/*
+** Given the Epoch-relative time of January 1, 00:00:00 GMT, in a year, the
+** year, a rule, and the offset from GMT at the time that rule takes effect,
+** calculate the Epoch-relative time that rule takes effect.
+*/
+
+static time_t
+transtime(janfirst, year, rulep, offset)
+const time_t janfirst;
+const int year;
+register const struct rule * const rulep;
+const long offset;
+{
+ register int leapyear;
+ register time_t value;
+ register int i;
+ int d, m1, yy0, yy1, yy2, dow;
+
+ leapyear = isleap(year);
+ switch (rulep->r_type) {
+
+ case JULIAN_DAY:
+ /*
+ ** Jn - Julian day, 1 == January 1, 60 == March 1 even in leap
+ ** years.
+ ** In non-leap years, or if the day number is 59 or less, just
+ ** add SECSPERDAY times the day number-1 to the time of
+ ** January 1, midnight, to get the day.
+ */
+ value = janfirst + (rulep->r_day - 1) * SECSPERDAY;
+ if (leapyear && rulep->r_day >= 60)
+ value += SECSPERDAY;
+ break;
+
+ case DAY_OF_YEAR:
+ /*
+ ** n - day of year.
+ ** Just add SECSPERDAY times the day number to the time of
+ ** January 1, midnight, to get the day.
+ */
+ value = janfirst + rulep->r_day * SECSPERDAY;
+ break;
+
+ case MONTH_NTH_DAY_OF_WEEK:
+ /*
+ ** Mm.n.d - nth "dth day" of month m.
+ */
+ value = janfirst;
+ for (i = 0; i < rulep->r_mon - 1; ++i)
+ value += mon_lengths[leapyear][i] * SECSPERDAY;
+
+ /*
+ ** Use Zeller's Congruence to get day-of-week of first day of
+ ** month.
+ */
+ m1 = (rulep->r_mon + 9) % 12 + 1;
+ yy0 = (rulep->r_mon <= 2) ? (year - 1) : year;
+ yy1 = yy0 / 100;
+ yy2 = yy0 % 100;
+ dow = ((26 * m1 - 2) / 10 +
+ 1 + yy2 + yy2 / 4 + yy1 / 4 - 2 * yy1) % 7;
+ if (dow < 0)
+ dow += DAYSPERWEEK;
+
+ /*
+ ** "dow" is the day-of-week of the first day of the month. Get
+ ** the day-of-month (zero-origin) of the first "dow" day of the
+ ** month.
+ */
+ d = rulep->r_day - dow;
+ if (d < 0)
+ d += DAYSPERWEEK;
+ for (i = 1; i < rulep->r_week; ++i) {
+ if (d + DAYSPERWEEK >=
+ mon_lengths[leapyear][rulep->r_mon - 1])
+ break;
+ d += DAYSPERWEEK;