[Emacs-diffs] Changes to emacs/src/mktime.c

[Dave Love]

Index: emacs/src/mktime.c
diff -c emacs/src/mktime.c:1.13 emacs/src/mktime.c:1.14
*** emacs/src/mktime.c:1.13     Mon Jun 19 09:05:51 2000
--- emacs/src/mktime.c  Thu Jun  5 12:24:17 2003
***************
*** 252,257 ****
--- 252,260 ----
    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;
***************
*** 270,275 ****
--- 273,285 ----
              + 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.  */
***************
*** 286,305 ****
    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;
         (dt = ydhms_tm_diff (year, yday, hour, min, sec,
                            ranged_convert (convert, &t, &tm)));
!        t1 = t2, t2 = t, t += dt)
      if (t == t1 && t != t2
!       && (isdst < 0 || 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.  */
        break;
      else if (--remaining_probes == 0)
        return -1;
--- 296,319 ----
    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, dst2 = 0;
         (dt = ydhms_tm_diff (year, yday, hour, min, sec,
                            ranged_convert (convert, &t, &tm)));
!        t1 = t2, t2 = t, t += dt, dst2 = tm.tm_isdst != 0)
      if (t == t1 && t != t2
!       && (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.  (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;
***************
*** 370,375 ****
--- 384,397 ----
        const time_t time_t_min = TIME_T_MIN;
  
        if (time_t_max / 3 - time_t_min / 3 < (dsec < 0 ? - dsec : dsec))
+       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;
      }