Expand the allowed range of timezone offsets to +/-15:59:59 from Greenwich.

We used to only allow offsets less than +/-13 hours, then it was +/14,
then it was +/-15.  That's still not good enough though, as per today's bug
report from Patric Bechtel.  This time I actually looked through the Olson
timezone database to find the largest offsets used anywhere.  The winners
are Asia/Manila, at -15:56:00 until 1844, and America/Metlakatla, at
+15:13:42 until 1867.  So we'd better allow offsets less than +/-16 hours.

Given the history, we are way overdue to have some greppable #define
symbols controlling this, so make some ... and also remove an obsolete
comment that didn't get fixed the last time.

Back-patch to all supported branches.

1 files changed, 2 insertions, 4 deletions

diff --git a/src/backend/utils/adt/datetime.c b/src/backend/utils/adt/datetime.c
index 31ae045da9..d5d34da552 100644
--- a/src/backend/utils/adt/datetime.c
+++ b/src/backend/utils/adt/datetime.c
@@ -2698,9 +2698,6 @@ DecodeNumberField(int len, char *str, int fmask,
  * Return 0 if okay (and set *tzp), a DTERR code if not okay.
  *
  * NB: this must *not* ereport on failure; see commands/variable.c.
- *
- * Note: we allow timezone offsets up to 13:59.  There are places that
- * use +1300 summer time.
  */
 static int
 DecodeTimezone(char *str, int *tzp)
@@ -2745,7 +2742,8 @@ DecodeTimezone(char *str, int *tzp)
 	else
 		min = 0;
 
-	if (hr < 0 || hr > 14)
+	/* Range-check the values; see notes in datatype/timestamp.h */
+	if (hr < 0 || hr > MAX_TZDISP_HOUR)
 		return DTERR_TZDISP_OVERFLOW;
 	if (min < 0 || min >= MINS_PER_HOUR)
 		return DTERR_TZDISP_OVERFLOW;