(__mktime_internal): Merge changes from gnulib

involving year 69 and dst2.
This commit is contained in:
Dave Love 2003-06-05 16:24:17 +00:00
parent 3811bec8ed
commit 984257db17

View file

@ -252,6 +252,9 @@ __mktime_internal (tp, convert, offset)
int year_requested = tp->tm_year;
int isdst = tp->tm_isdst;
/* 1 if the previous probe was DST. */
int dst2;
/* Ensure that mon is in range, and set year accordingly. */
int mon_remainder = mon % 12;
int negative_mon_remainder = mon_remainder < 0;
@ -270,6 +273,13 @@ __mktime_internal (tp, convert, offset)
+ mday - 1);
int sec_requested = sec;
/* Only years after 1970 are defined.
If year is 69, it might still be representable due to
timezone differences. */
if (year < 69)
return -1;
#if LEAP_SECONDS_POSSIBLE
/* Handle out-of-range seconds specially,
since ydhms_tm_diff assumes every minute has 60 seconds. */
@ -286,20 +296,24 @@ __mktime_internal (tp, convert, offset)
tm.tm_yday = tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
t0 = ydhms_tm_diff (year, yday, hour, min, sec, &tm);
for (t = t1 = t2 = t0 + *offset;
for (t = t1 = t2 = t0 + *offset, dst2 = 0;
(dt = ydhms_tm_diff (year, yday, hour, min, sec,
ranged_convert (convert, &t, &tm)));
t1 = t2, t2 = t, t += dt)
t1 = t2, t2 = t, t += dt, dst2 = tm.tm_isdst != 0)
if (t == t1 && t != t2
&& (isdst < 0 || tm.tm_isdst < 0
|| (isdst != 0) != (tm.tm_isdst != 0)))
&& (tm.tm_isdst < 0
|| (isdst < 0
? dst2 <= (tm.tm_isdst != 0)
: (isdst != 0) != (tm.tm_isdst != 0))))
/* We can't possibly find a match, as we are oscillating
between two values. The requested time probably falls
within a spring-forward gap of size DT. Follow the common
practice in this case, which is to return a time that is DT
away from the requested time, preferring a time whose
tm_isdst differs from the requested value. In practice,
this is more useful than returning -1. */
tm_isdst differs from the requested value. (If no tm_isdst
was requested and only one of the two values has a nonzero
tm_isdst, prefer that value.) In practice, this is more
useful than returning -1. */
break;
else if (--remaining_probes == 0)
return -1;
@ -373,6 +387,14 @@ __mktime_internal (tp, convert, offset)
return -1;
}
if (year == 69)
{
/* If year was 69, need to check whether the time was representable
or not. */
if (t < 0 || t > 2 * 24 * 60 * 60)
return -1;
}
*tp = tm;
return t;
}