Sync our copy of the timezone library with IANA release tzcode2017b.

zic no longer mishandles some transitions in January 2038 when it
attempts to work around Qt bug 53071.  This fixes a bug affecting
Pacific/Tongatapu that was introduced in zic 2016e.  localtime.c
now contains a workaround, useful when loading a file generated by
a buggy zic.

There are assorted cosmetic changes as well, notably relocation
of a bunch of #defines.

Author: tglsfdc

src/timezone/README

@@ -50,7 +50,7 @@ match properly on the old version.
 Time Zone code
 ==============
 
-The code in this directory is currently synced with tzcode release 2016j.
+The code in this directory is currently synced with tzcode release 2017b.
 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.

src/timezone/localtime.c

@@ -17,8 +17,9 @@
 #include <fcntl.h>
 
 #include "datatype/timestamp.h"
-#include "private.h"
 #include "pgtz.h"
+
+#include "private.h"
 #include "tzfile.h"
 
 
@@ -414,10 +415,10 @@ tzloadbody(char const * name, char *canonname, struct state * sp, bool doextend,
 		{
 			/*
 			 * Attempt to reuse existing abbreviations. Without this,
-			 * America/Anchorage would stop working after 2037 when
-			 * TZ_MAX_CHARS is 50, as sp->charcnt equals 42 (for LMT CAT CAWT
-			 * CAPT AHST AHDT YST AKDT AKST) and ts->charcnt equals 10 (for
-			 * AKST AKDT).  Reusing means sp->charcnt can stay 42 in this
+			 * America/Anchorage would be right on the edge after 2037 when
+			 * TZ_MAX_CHARS is 50, as sp->charcnt equals 40 (for LMT AST AWT
+			 * APT AHST AHDT YST AKDT AKST) and ts->charcnt equals 10 (for
+			 * AKST AKDT).  Reusing means sp->charcnt can stay 40 in this
 			 * example.
 			 */
 			int			gotabbr = 0;
@@ -451,6 +452,17 @@ tzloadbody(char const * name, char *canonname, struct state * sp, bool doextend,
 			if (gotabbr == 2)
 			{
 				sp->charcnt = charcnt;
+
+				/*
+				 * Ignore any trailing, no-op transitions generated by zic as
+				 * they don't help here and can run afoul of bugs in zic 2016j
+				 * or earlier.
+				 */
+				while (1 < sp->timecnt
+					   && (sp->types[sp->timecnt - 1]
+						   == sp->types[sp->timecnt - 2]))
+					sp->timecnt--;
+
 				for (i = 0; i < ts->timecnt; i++)
 					if (sp->ats[sp->timecnt - 1] < ts->ats[i])
 						break;
@@ -974,6 +986,8 @@ tzparse(const char *name, struct state * sp, bool lastditch)
 			int			yearlim;
 			int			timecnt;
 			pg_time_t	janfirst;
+			int32		janoffset = 0;
+			int			yearbeg;
 
 			++name;
 			if ((name = getrule(name, &start)) == NULL)
@@ -994,8 +1008,23 @@ tzparse(const char *name, struct state * sp, bool lastditch)
 			sp->defaulttype = 0;
 			timecnt = 0;
 			janfirst = 0;
-			yearlim = EPOCH_YEAR + YEARSPERREPEAT;
-			for (year = EPOCH_YEAR; year < yearlim; year++)
+			yearbeg = EPOCH_YEAR;
+
+			do
+			{
+				int32		yearsecs
+				= year_lengths[isleap(yearbeg - 1)] * SECSPERDAY;
+
+				yearbeg--;
+				if (increment_overflow_time(&janfirst, -yearsecs))
+				{
+					janoffset = -yearsecs;
+					break;
+				}
+			} while (EPOCH_YEAR - YEARSPERREPEAT / 2 < yearbeg);
+
+			yearlim = yearbeg + YEARSPERREPEAT + 1;
+			for (year = yearbeg; year < yearlim; year++)
 			{
 				int32
 							starttime = transtime(year, &start, stdoffset),
@@ -1020,24 +1049,34 @@ tzparse(const char *name, struct state * sp, bool lastditch)
 				{
 					if (TZ_MAX_TIMES - 2 < timecnt)
 						break;
-					yearlim = year + YEARSPERREPEAT + 1;
 					sp->ats[timecnt] = janfirst;
-					if (increment_overflow_time
-						(&sp->ats[timecnt], starttime))
-						break;
-					sp->types[timecnt++] = reversed;
+					if (!increment_overflow_time
+						(&sp->ats[timecnt],
+						 janoffset + starttime))
+						sp->types[timecnt++] = reversed;
+					else if (janoffset)
+						sp->defaulttype = reversed;
 					sp->ats[timecnt] = janfirst;
-					if (increment_overflow_time
-						(&sp->ats[timecnt], endtime))
-						break;
-					sp->types[timecnt++] = !reversed;
+					if (!increment_overflow_time
+						(&sp->ats[timecnt],
+						 janoffset + endtime))
+					{
+						sp->types[timecnt++] = !reversed;
+						yearlim = year + YEARSPERREPEAT + 1;
+					}
+					else if (janoffset)
+						sp->defaulttype = !reversed;
 				}
-				if (increment_overflow_time(&janfirst, yearsecs))
+				if (increment_overflow_time
+					(&janfirst, janoffset + yearsecs))
 					break;
+				janoffset = 0;
 			}
 			sp->timecnt = timecnt;
 			if (!timecnt)
 				sp->typecnt = 1;	/* Perpetual DST.  */
+			else if (YEARSPERREPEAT < year - yearbeg)
+				sp->goback = sp->goahead = true;
 		}
 		else
 		{

src/timezone/pgtz.c

@@ -17,6 +17,7 @@
 #include <sys/stat.h>
 #include <time.h>
 
+#include "datatype/timestamp.h"
 #include "miscadmin.h"
 #include "pgtz.h"
 #include "storage/fd.h"
@@ -308,14 +309,14 @@ pg_tzset_offset(long gmtoffset)
 	char		tzname[128];
 
 	snprintf(offsetstr, sizeof(offsetstr),
-			 "%02ld", absoffset / SECSPERHOUR);
-	absoffset %= SECSPERHOUR;
+			 "%02ld", absoffset / SECS_PER_HOUR);
+	absoffset %= SECS_PER_HOUR;
 	if (absoffset != 0)
 	{
 		snprintf(offsetstr + strlen(offsetstr),
 				 sizeof(offsetstr) - strlen(offsetstr),
-				 ":%02ld", absoffset / SECSPERMIN);
-		absoffset %= SECSPERMIN;
+				 ":%02ld", absoffset / SECS_PER_MINUTE);
+		absoffset %= SECS_PER_MINUTE;
 		if (absoffset != 0)
 			snprintf(offsetstr + strlen(offsetstr),
 					 sizeof(offsetstr) - strlen(offsetstr),

src/timezone/private.h

@@ -67,14 +67,8 @@ extern int	unlink(const char *filename);
  * Finally, some convenience items.
  */
 
-#ifndef TYPE_BIT
 #define TYPE_BIT(type)	(sizeof (type) * CHAR_BIT)
-#endif   /* !defined TYPE_BIT */
-
-#ifndef TYPE_SIGNED
 #define TYPE_SIGNED(type) (((type) -1) < 0)
-#endif   /* !defined TYPE_SIGNED */
-
 #define TWOS_COMPLEMENT(t) ((t) ~ (t) 0 < 0)
 
 /*
@@ -88,7 +82,6 @@ extern int	unlink(const char *filename);
 #define MINVAL(t, b)						\
   ((t) (TYPE_SIGNED(t) ? - TWOS_COMPLEMENT(t) - MAXVAL(t, b) : 0))
 
-#ifndef INT_STRLEN_MAXIMUM
 /*
  * 302 / 1000 is log10(2.0) rounded up.
  * Subtract one for the sign bit if the type is signed;
@@ -98,7 +91,6 @@ extern int	unlink(const char *filename);
 #define INT_STRLEN_MAXIMUM(type) \
 	((TYPE_BIT(type) - TYPE_SIGNED(type)) * 302 / 1000 + \
 	1 + TYPE_SIGNED(type))
-#endif   /* !defined INT_STRLEN_MAXIMUM */
 
 /*
  * INITIALIZE(x)
@@ -108,24 +100,70 @@ extern int	unlink(const char *filename);
 #undef _
 #define _(msgid) (msgid)
 
-#ifndef YEARSPERREPEAT
+/* Handy macros that are independent of tzfile implementation.  */
+
 #define YEARSPERREPEAT		400 /* years before a Gregorian repeat */
-#endif   /* !defined YEARSPERREPEAT */
+
+#define SECSPERMIN	60
+#define MINSPERHOUR 60
+#define HOURSPERDAY 24
+#define DAYSPERWEEK 7
+#define DAYSPERNYEAR	365
+#define DAYSPERLYEAR	366
+#define SECSPERHOUR (SECSPERMIN * MINSPERHOUR)
+#define SECSPERDAY	((int32) SECSPERHOUR * HOURSPERDAY)
+#define MONSPERYEAR 12
+
+#define TM_SUNDAY	0
+#define TM_MONDAY	1
+#define TM_TUESDAY	2
+#define TM_WEDNESDAY	3
+#define TM_THURSDAY 4
+#define TM_FRIDAY	5
+#define TM_SATURDAY 6
+
+#define TM_JANUARY	0
+#define TM_FEBRUARY 1
+#define TM_MARCH	2
+#define TM_APRIL	3
+#define TM_MAY		4
+#define TM_JUNE		5
+#define TM_JULY		6
+#define TM_AUGUST	7
+#define TM_SEPTEMBER	8
+#define TM_OCTOBER	9
+#define TM_NOVEMBER 10
+#define TM_DECEMBER 11
+
+#define TM_YEAR_BASE	1900
+
+#define EPOCH_YEAR	1970
+#define EPOCH_WDAY	TM_THURSDAY
+
+#define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
 
 /*
- * The Gregorian year averages 365.2425 days, which is 31556952 seconds.
+ * Since everything in isleap is modulo 400 (or a factor of 400), we know that
+ *	isleap(y) == isleap(y % 400)
+ * and so
+ *	isleap(a + b) == isleap((a + b) % 400)
+ * or
+ *	isleap(a + b) == isleap(a % 400 + b % 400)
+ * This is true even if % means modulo rather than Fortran remainder
+ * (which is allowed by C89 but not C99).
+ * We use this to avoid addition overflow problems.
  */
 
-#ifndef AVGSECSPERYEAR
-#define AVGSECSPERYEAR		31556952L
-#endif   /* !defined AVGSECSPERYEAR */
+#define isleap_sum(a, b)	isleap((a) % 400 + (b) % 400)
 
-#ifndef SECSPERREPEAT
-#define SECSPERREPEAT		((int64) YEARSPERREPEAT * (int64) AVGSECSPERYEAR)
-#endif   /* !defined SECSPERREPEAT */
 
-#ifndef SECSPERREPEAT_BITS
+/*
+ * The Gregorian year averages 365.2425 days, which is 31556952 seconds.
+ */
+
+#define AVGSECSPERYEAR		31556952L
+#define SECSPERREPEAT \
+  ((int64) YEARSPERREPEAT * (int64) AVGSECSPERYEAR)
 #define SECSPERREPEAT_BITS	34	/* ceil(log2(SECSPERREPEAT)) */
-#endif   /* !defined SECSPERREPEAT_BITS */
 
 #endif   /* !defined PRIVATE_H */

src/timezone/strftime.c

@@ -1,4 +1,4 @@
-/* Convert a broken-down time stamp to a string. */
+/* Convert a broken-down timestamp to a string. */
 
 /*
  * Copyright 1989 The Regents of the University of California.
@@ -44,7 +44,6 @@
 #include <locale.h>
 
 #include "private.h"
-#include "tzfile.h"
 
 
 struct lc_time_T
@@ -452,11 +451,17 @@ _fmt(const char *format, const struct pg_tm * t, char *pt, const char *ptlim,
 					{
 						long		diff;
 						char const *sign;
+						bool		negative;
 
 						if (t->tm_isdst < 0)
 							continue;
 						diff = t->tm_gmtoff;
-						if (diff < 0)
+						negative = diff < 0;
+						if (diff == 0)
+						{
+							negative = t->tm_zone[0] == '-';
+						}
+						if (negative)
 						{
 							sign = "-";
 							diff = -diff;

src/timezone/tzfile.h

@@ -100,56 +100,4 @@ struct tzhead
 
 #define TZ_MAX_LEAPS	50		/* Maximum number of leap second corrections */
 
-#define SECSPERMIN	60
-#define MINSPERHOUR 60
-#define HOURSPERDAY 24
-#define DAYSPERWEEK 7
-#define DAYSPERNYEAR	365
-#define DAYSPERLYEAR	366
-#define SECSPERHOUR (SECSPERMIN * MINSPERHOUR)
-#define SECSPERDAY	((int32) SECSPERHOUR * HOURSPERDAY)
-#define MONSPERYEAR 12
-
-#define TM_SUNDAY	0
-#define TM_MONDAY	1
-#define TM_TUESDAY	2
-#define TM_WEDNESDAY	3
-#define TM_THURSDAY 4
-#define TM_FRIDAY	5
-#define TM_SATURDAY 6
-
-#define TM_JANUARY	0
-#define TM_FEBRUARY 1
-#define TM_MARCH	2
-#define TM_APRIL	3
-#define TM_MAY		4
-#define TM_JUNE		5
-#define TM_JULY		6
-#define TM_AUGUST	7
-#define TM_SEPTEMBER	8
-#define TM_OCTOBER	9
-#define TM_NOVEMBER 10
-#define TM_DECEMBER 11
-
-#define TM_YEAR_BASE	1900
-
-#define EPOCH_YEAR	1970
-#define EPOCH_WDAY	TM_THURSDAY
-
-#define isleap(y) (((y) % 4) == 0 && (((y) % 100) != 0 || ((y) % 400) == 0))
-
-/*
- * Since everything in isleap is modulo 400 (or a factor of 400), we know that
- *	  isleap(y) == isleap(y % 400)
- * and so
- *	  isleap(a + b) == isleap((a + b) % 400)
- * or
- *	  isleap(a + b) == isleap(a % 400 + b % 400)
- * This is true even if % means modulo rather than Fortran remainder
- * (which is allowed by C89 but not C99).
- * We use this to avoid addition overflow problems.
- */
-
-#define isleap_sum(a, b)	isleap((a) % 400 + (b) % 400)
-
 #endif   /* !defined TZFILE_H */