Sync our copy of the timezone library with IANA release tzcode2019b.

A large fraction of this diff is just due to upstream's somewhat
random decision to rename a bunch of internal variables and struct
fields.  However, there is an interesting new feature in zic:
it's grown a "-b slim" option that emits zone files without 32-bit
data and other backwards-compatibility hacks.  We should consider
whether we wish to enable that.

src/timezone/README

@@ -55,7 +55,7 @@ match properly on the old version.
 Time Zone code
 ==============
 
-The code in this directory is currently synced with tzcode release 2019a.
+The code in this directory is currently synced with tzcode release 2019b.
 There are many cosmetic (and not so cosmetic) differences from the
 original tzcode library, but diffs in the upstream version should usually
 be propagated to our version.  Here are some notes about that.
@@ -127,4 +127,7 @@ and then run them through pgindent.  (The first three sed patterns deal
 with conversion of their block comment style to something pgindent
 won't make a hash of; the remainder address other points noted above.)
 After that, the files can be diff'd directly against our corresponding
-files.
+files.  Also, it's typically helpful to diff against the previous tzcode
+release (after processing that the same way), and then try to apply the
+diff to our files.  This will take care of most of the changes
+mechanically.

src/timezone/localtime.c

@@ -107,15 +107,15 @@ static bool typesequiv(struct state const *, int, int);
 
 static struct pg_tm tm;
 
-/* Initialize *S to a value based on GMTOFF, ISDST, and ABBRIND.  */
+/* Initialize *S to a value based on UTOFF, ISDST, and DESIGIDX.  */
 static void
-init_ttinfo(struct ttinfo *s, int32 gmtoff, bool isdst, int abbrind)
+init_ttinfo(struct ttinfo *s, int32 utoff, bool isdst, int desigidx)
 {
-	s->tt_gmtoff = gmtoff;
+	s->tt_utoff = utoff;
 	s->tt_isdst = isdst;
-	s->tt_abbrind = abbrind;
+	s->tt_desigidx = desigidx;
 	s->tt_ttisstd = false;
-	s->tt_ttisgmt = false;
+	s->tt_ttisut = false;
 }
 
 static int32
@@ -251,7 +251,7 @@ tzloadbody(char const *name, char *canonname, struct state *sp, bool doextend,
 	for (stored = 4; stored <= 8; stored *= 2)
 	{
 		int32		ttisstdcnt = detzcode(up->tzhead.tzh_ttisstdcnt);
-		int32		ttisgmtcnt = detzcode(up->tzhead.tzh_ttisgmtcnt);
+		int32		ttisutcnt = detzcode(up->tzhead.tzh_ttisutcnt);
 		int64		prevtr = 0;
 		int32		prevcorr = 0;
 		int32		leapcnt = detzcode(up->tzhead.tzh_leapcnt);
@@ -270,7 +270,7 @@ tzloadbody(char const *name, char *canonname, struct state *sp, bool doextend,
 			  && 0 <= timecnt && timecnt < TZ_MAX_TIMES
 			  && 0 <= charcnt && charcnt < TZ_MAX_CHARS
 			  && (ttisstdcnt == typecnt || ttisstdcnt == 0)
-			  && (ttisgmtcnt == typecnt || ttisgmtcnt == 0)))
+			  && (ttisutcnt == typecnt || ttisutcnt == 0)))
 			return EINVAL;
 		if (nread
 			< (tzheadsize		/* struct tzhead */
@@ -280,7 +280,7 @@ tzloadbody(char const *name, char *canonname, struct state *sp, bool doextend,
 			   + charcnt		/* chars */
 			   + leapcnt * (stored + 4) /* lsinfos */
 			   + ttisstdcnt		/* ttisstds */
-			   + ttisgmtcnt))	/* ttisgmts */
+			   + ttisutcnt))	/* ttisuts */
 			return EINVAL;
 		sp->leapcnt = leapcnt;
 		sp->timecnt = timecnt;
@@ -332,19 +332,19 @@ tzloadbody(char const *name, char *canonname, struct state *sp, bool doextend,
 		{
 			struct ttinfo *ttisp;
 			unsigned char isdst,
-						abbrind;
+						desigidx;
 
 			ttisp = &sp->ttis[i];
-			ttisp->tt_gmtoff = detzcode(p);
+			ttisp->tt_utoff = detzcode(p);
 			p += 4;
 			isdst = *p++;
 			if (!(isdst < 2))
 				return EINVAL;
 			ttisp->tt_isdst = isdst;
-			abbrind = *p++;
-			if (!(abbrind < sp->charcnt))
+			desigidx = *p++;
+			if (!(desigidx < sp->charcnt))
 				return EINVAL;
-			ttisp->tt_abbrind = abbrind;
+			ttisp->tt_desigidx = desigidx;
 		}
 		for (i = 0; i < sp->charcnt; ++i)
 			sp->chars[i] = *p++;
@@ -398,13 +398,13 @@ tzloadbody(char const *name, char *canonname, struct state *sp, bool doextend,
 			struct ttinfo *ttisp;
 
 			ttisp = &sp->ttis[i];
-			if (ttisgmtcnt == 0)
-				ttisp->tt_ttisgmt = false;
+			if (ttisutcnt == 0)
+				ttisp->tt_ttisut = false;
 			else
 			{
 				if (*p != true && *p != false)
 					return EINVAL;
-				ttisp->tt_ttisgmt = *p++;
+				ttisp->tt_ttisut = *p++;
 			}
 		}
 
@@ -438,13 +438,13 @@ tzloadbody(char const *name, char *canonname, struct state *sp, bool doextend,
 
 			for (i = 0; i < ts->typecnt; i++)
 			{
-				char	   *tsabbr = ts->chars + ts->ttis[i].tt_abbrind;
+				char	   *tsabbr = ts->chars + ts->ttis[i].tt_desigidx;
 				int			j;
 
 				for (j = 0; j < charcnt; j++)
 					if (strcmp(sp->chars + j, tsabbr) == 0)
 					{
-						ts->ttis[i].tt_abbrind = j;
+						ts->ttis[i].tt_desigidx = j;
 						gotabbr++;
 						break;
 					}
@@ -456,7 +456,7 @@ tzloadbody(char const *name, char *canonname, struct state *sp, bool doextend,
 					{
 						strcpy(sp->chars + j, tsabbr);
 						charcnt = j + tsabbrlen + 1;
-						ts->ttis[i].tt_abbrind = j;
+						ts->ttis[i].tt_desigidx = j;
 						gotabbr++;
 					}
 				}
@@ -614,12 +614,13 @@ typesequiv(const struct state *sp, int a, int b)
 		const struct ttinfo *ap = &sp->ttis[a];
 		const struct ttinfo *bp = &sp->ttis[b];
 
-		result = ap->tt_gmtoff == bp->tt_gmtoff &&
-			ap->tt_isdst == bp->tt_isdst &&
-			ap->tt_ttisstd == bp->tt_ttisstd &&
-			ap->tt_ttisgmt == bp->tt_ttisgmt &&
-			strcmp(&sp->chars[ap->tt_abbrind],
-				   &sp->chars[bp->tt_abbrind]) == 0;
+		result = (ap->tt_utoff == bp->tt_utoff
+				  && ap->tt_isdst == bp->tt_isdst
+				  && ap->tt_ttisstd == bp->tt_ttisstd
+				  && ap->tt_ttisut == bp->tt_ttisut
+				  && (strcmp(&sp->chars[ap->tt_desigidx],
+							 &sp->chars[bp->tt_desigidx])
+					  == 0));
 	}
 	return result;
 }
@@ -1176,7 +1177,7 @@ tzparse(const char *name, struct state *sp, bool lastditch)
 				if (!sp->ttis[j].tt_isdst)
 				{
 					theirstdoffset =
-						-sp->ttis[j].tt_gmtoff;
+						-sp->ttis[j].tt_utoff;
 					break;
 				}
 			}
@@ -1187,7 +1188,7 @@ tzparse(const char *name, struct state *sp, bool lastditch)
 				if (sp->ttis[j].tt_isdst)
 				{
 					theirdstoffset =
-						-sp->ttis[j].tt_gmtoff;
+						-sp->ttis[j].tt_utoff;
 					break;
 				}
 			}
@@ -1206,7 +1207,7 @@ tzparse(const char *name, struct state *sp, bool lastditch)
 			{
 				j = sp->types[i];
 				sp->types[i] = sp->ttis[j].tt_isdst;
-				if (sp->ttis[j].tt_ttisgmt)
+				if (sp->ttis[j].tt_ttisut)
 				{
 					/* No adjustment to transition time */
 				}
@@ -1234,7 +1235,7 @@ tzparse(const char *name, struct state *sp, bool lastditch)
 							theirstdoffset;
 					}
 				}
-				theiroffset = -sp->ttis[j].tt_gmtoff;
+				theiroffset = -sp->ttis[j].tt_utoff;
 				if (sp->ttis[j].tt_isdst)
 					theirdstoffset = theiroffset;
 				else
@@ -1357,14 +1358,14 @@ localsub(struct state const *sp, pg_time_t const *timep,
 
 	/*
 	 * To get (wrong) behavior that's compatible with System V Release 2.0
-	 * you'd replace the statement below with t += ttisp->tt_gmtoff;
+	 * you'd replace the statement below with t += ttisp->tt_utoff;
 	 * timesub(&t, 0L, sp, tmp);
 	 */
-	result = timesub(&t, ttisp->tt_gmtoff, sp, tmp);
+	result = timesub(&t, ttisp->tt_utoff, sp, tmp);
 	if (result)
 	{
 		result->tm_isdst = ttisp->tt_isdst;
-		result->tm_zone = unconstify(char *, &sp->chars[ttisp->tt_abbrind]);
+		result->tm_zone = unconstify(char *, &sp->chars[ttisp->tt_desigidx]);
 	}
 	return result;
 }
@@ -1647,7 +1648,7 @@ pg_next_dst_boundary(const pg_time_t *timep,
 				break;
 			}
 		ttisp = &sp->ttis[i];
-		*before_gmtoff = ttisp->tt_gmtoff;
+		*before_gmtoff = ttisp->tt_utoff;
 		*before_isdst = ttisp->tt_isdst;
 		return 0;
 	}
@@ -1700,7 +1701,7 @@ pg_next_dst_boundary(const pg_time_t *timep,
 		/* No known transition > t, so use last known segment's type */
 		i = sp->types[sp->timecnt - 1];
 		ttisp = &sp->ttis[i];
-		*before_gmtoff = ttisp->tt_gmtoff;
+		*before_gmtoff = ttisp->tt_utoff;
 		*before_isdst = ttisp->tt_isdst;
 		return 0;
 	}
@@ -1715,13 +1716,13 @@ pg_next_dst_boundary(const pg_time_t *timep,
 				break;
 			}
 		ttisp = &sp->ttis[i];
-		*before_gmtoff = ttisp->tt_gmtoff;
+		*before_gmtoff = ttisp->tt_utoff;
 		*before_isdst = ttisp->tt_isdst;
 		*boundary = sp->ats[0];
 		/* And for "after", use the first segment's type */
 		i = sp->types[0];
 		ttisp = &sp->ttis[i];
-		*after_gmtoff = ttisp->tt_gmtoff;
+		*after_gmtoff = ttisp->tt_utoff;
 		*after_isdst = ttisp->tt_isdst;
 		return 1;
 	}
@@ -1743,12 +1744,12 @@ pg_next_dst_boundary(const pg_time_t *timep,
 	}
 	j = sp->types[i - 1];
 	ttisp = &sp->ttis[j];
-	*before_gmtoff = ttisp->tt_gmtoff;
+	*before_gmtoff = ttisp->tt_utoff;
 	*before_isdst = ttisp->tt_isdst;
 	*boundary = sp->ats[i];
 	j = sp->types[i];
 	ttisp = &sp->ttis[j];
-	*after_gmtoff = ttisp->tt_gmtoff;
+	*after_gmtoff = ttisp->tt_utoff;
 	*after_isdst = ttisp->tt_isdst;
 	return 1;
 }
@@ -1832,9 +1833,9 @@ pg_interpret_timezone_abbrev(const char *abbrev,
 	for (i = cutoff - 1; i >= 0; i--)
 	{
 		ttisp = &sp->ttis[sp->types[i]];
-		if (ttisp->tt_abbrind == abbrind)
+		if (ttisp->tt_desigidx == abbrind)
 		{
-			*gmtoff = ttisp->tt_gmtoff;
+			*gmtoff = ttisp->tt_utoff;
 			*isdst = ttisp->tt_isdst;
 			return true;
 		}
@@ -1846,9 +1847,9 @@ pg_interpret_timezone_abbrev(const char *abbrev,
 	for (i = cutoff; i < sp->timecnt; i++)
 	{
 		ttisp = &sp->ttis[sp->types[i]];
-		if (ttisp->tt_abbrind == abbrind)
+		if (ttisp->tt_desigidx == abbrind)
 		{
-			*gmtoff = ttisp->tt_gmtoff;
+			*gmtoff = ttisp->tt_utoff;
 			*isdst = ttisp->tt_isdst;
 			return true;
 		}
@@ -1875,10 +1876,10 @@ pg_get_timezone_offset(const pg_tz *tz, long int *gmtoff)
 	sp = &tz->state;
 	for (i = 1; i < sp->typecnt; i++)
 	{
-		if (sp->ttis[i].tt_gmtoff != sp->ttis[0].tt_gmtoff)
+		if (sp->ttis[i].tt_utoff != sp->ttis[0].tt_utoff)
 			return false;
 	}
-	*gmtoff = sp->ttis[0].tt_gmtoff;
+	*gmtoff = sp->ttis[0].tt_utoff;
 	return true;
 }
 

src/timezone/pgtz.h

@@ -25,11 +25,11 @@
 
 struct ttinfo
 {								/* time type information */
-	int32		tt_gmtoff;		/* UT offset in seconds */
+	int32		tt_utoff;		/* UT offset in seconds */
 	bool		tt_isdst;		/* used to set tm_isdst */
-	int			tt_abbrind;		/* abbreviation list index */
+	int			tt_desigidx;	/* abbreviation list index */
 	bool		tt_ttisstd;		/* transition is std time */
-	bool		tt_ttisgmt;		/* transition is UT */
+	bool		tt_ttisut;		/* transition is UT */
 };
 
 struct lsinfo

src/timezone/tzfile.h

@@ -41,7 +41,7 @@ struct tzhead
 	char		tzh_magic[4];	/* TZ_MAGIC */
 	char		tzh_version[1]; /* '\0' or '2' or '3' as of 2013 */
 	char		tzh_reserved[15];	/* reserved; must be zero */
-	char		tzh_ttisgmtcnt[4];	/* coded number of trans. time flags */
+	char		tzh_ttisutcnt[4];	/* coded number of trans. time flags */
 	char		tzh_ttisstdcnt[4];	/* coded number of trans. time flags */
 	char		tzh_leapcnt[4]; /* coded number of leap seconds */
 	char		tzh_timecnt[4]; /* coded number of transition times */
@@ -64,14 +64,15 @@ struct tzhead
  *		one (char [4])		total correction after above
  *	tzh_ttisstdcnt (char)s		indexed by type; if 1, transition
  *					time is standard time, if 0,
- *					transition time is wall clock time
- *					if absent, transition times are
- *					assumed to be wall clock time
- *	tzh_ttisgmtcnt (char)s		indexed by type; if 1, transition
- *					time is UT, if 0,
- *					transition time is local time
- *					if absent, transition times are
+ *					transition time is local (wall clock)
+ *					time; if absent, transition times are
  *					assumed to be local time
+ *	tzh_ttisutcnt (char)s		indexed by type; if 1, transition
+ *					time is UT, if 0, transition time is
+ *					local time; if absent, transition
+ *					times are assumed to be local time.
+ *					When this is 1, the corresponding
+ *					std/wall indicator must also be 1.
  */
 
 /*