A revised time patch

[hjl@lucon.org (H.J. Lu)]

Hi,

Here is a revised time patch. Now it passes all mktime
tests in VSX-PCT. The testcase is in my previous email.

BTW, you also need my timezone patch.


Thanks.


-- 
H.J. Lu (hjl@gnu.org)
---
Fri Oct 30 17:48:48 1998  H.J. Lu  <hjl@gnu.org>

	* time/mktime.c (__mktime_internal): Handle the case where
	tm_isdst is different from __daylight != 0 correctly.

	* time/tzfile (__tzfile_read): Set __daylight to the difference
	between DST and STD.
	(__tzfile_compute): Likewise.
	* time/tzset.c (tz_compute): Likewise.

Index: time/mktime.c
===================================================================
RCS file: /home/work/cvs/gnu/glibc/time/mktime.c,v
retrieving revision 1.1.1.13
diff -u -p -r1.1.1.13 mktime.c
--- time/mktime.c	1998/10/17 02:11:00	1.1.1.13
+++ time/mktime.c	1998/10/31 01:45:11
@@ -334,10 +334,13 @@ __mktime_internal (tp, convert, 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
+    if ((0 <= isdst && 0 <= tm.tm_isdst
+	 && dt == __daylight * ((isdst != 0) - (tm.tm_isdst != 0)))
+	|| (t == t1 && t != t2
+	    && (isdst < 0 || tm.tm_isdst < 0
+		|| (isdst != 0) != (tm.tm_isdst != 0))))
+      /* We find a match due to difference between STD and DST. Or
+	 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
@@ -355,11 +358,11 @@ __mktime_internal (tp, convert, offset)
       int dst_diff = (isdst != 0) - (tm.tm_isdst != 0);
       if (dst_diff)
 	{
-	  /* Move two hours in the direction indicated by the disagreement,
-	     probe some more, and switch to a new time if found.
-	     The largest known fallback due to daylight savings is two hours:
-	     once, in Newfoundland, 1988-10-30 02:00 -> 00:00.  */
-	  time_t ot = t - 2 * 60 * 60 * dst_diff;
+	  /* Move __daylight seconds in the direction indicated by the
+	     disagreement, probe some more, and switch to a new time
+	     if found. The fallback due to daylight savings is stored
+	     in __daylight.  */
+	  time_t ot = t - __daylight * dst_diff;
 	  while (--remaining_probes != 0)
 	    {
 	      struct tm otm;
Index: time/tzfile.c
===================================================================
RCS file: /home/work/cvs/gnu/glibc/time/tzfile.c,v
retrieving revision 1.1.1.13
diff -u -p -r1.1.1.13 tzfile.c
--- time/tzfile.c	1998/10/26 15:33:26	1.1.1.13
+++ time/tzfile.c	1998/10/28 17:32:31
@@ -298,7 +298,7 @@ __tzfile_read (const char *file)
 	}
     }
 
-  __daylight = rule_stdoff != rule_dstoff;
+  __daylight = rule_dstoff - rule_stdoff;
   __timezone = -rule_stdoff;
 
   __use_tzfile = 1;
@@ -436,7 +436,7 @@ __tzfile_compute (time_t timer, int use_
   if (use_localtime)
     {
       struct ttinfo *info = find_transition (timer);
-      __daylight = rule_stdoff != rule_dstoff;
+      __daylight = rule_dstoff - rule_stdoff;
       __timezone = -rule_stdoff;
       __tzname[1] = NULL;
       for (i = 0; i < num_types; ++i)
Index: time/tzset.c
===================================================================
RCS file: /home/work/cvs/gnu/glibc/time/tzset.c,v
retrieving revision 1.1.1.16
diff -u -p -r1.1.1.16 tzset.c
--- time/tzset.c	1998/10/26 23:24:25	1.1.1.16
+++ time/tzset.c	1998/10/28 17:34:50
@@ -528,7 +528,7 @@ tz_compute (timer, tm)
       && ! compute_change (&tz_rules[1], 1900 + tm->tm_year + 1))
     return 0;
 
-  __daylight = tz_rules[0].offset != tz_rules[1].offset;
+  __daylight = tz_rules[1].offset - tz_rules[0].offset;
   __timezone = -tz_rules[0].offset;
   __tzname[0] = (char *) tz_rules[0].name;
   __tzname[1] = (char *) tz_rules[1].name;