From f2ebd01ef02968c03c3886296de3242bbc5f817d Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Fri, 9 Sep 2005 06:46:14 +0000
Subject: [PATCH] timestamptz_izone should return the input, not NULL, when the
 input is a non-finite timestamp, for consistency with related functions. In
 other words: +infinity rotated to a different timezone is still +infinity.

---
 src/backend/utils/adt/timestamp.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index b2d6f774c2..8f18b870b5 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.152 2005/09/09 02:31:49 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.153 2005/09/09 06:46:14 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1897,18 +1897,14 @@ timestamp_mi(PG_FUNCTION_ARGS)
 	result = (Interval *) palloc(sizeof(Interval));
 
 	if (TIMESTAMP_NOT_FINITE(dt1) || TIMESTAMP_NOT_FINITE(dt2))
-	{
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
 				 errmsg("cannot subtract infinite timestamps")));
 
-		result->time = 0;
-	}
-	else
 #ifdef HAVE_INT64_TIMESTAMP
-		result->time = dt1 - dt2;
+	result->time = dt1 - dt2;
 #else
-		result->time = JROUND(dt1 - dt2);
+	result->time = JROUND(dt1 - dt2);
 #endif
 
 	result->month = 0;
@@ -4196,7 +4192,7 @@ timestamptz_izone(PG_FUNCTION_ARGS)
 	int			tz;
 
 	if (TIMESTAMP_NOT_FINITE(timestamp))
-		PG_RETURN_NULL();
+		PG_RETURN_TIMESTAMP(timestamp);
 
 	if (zone->month != 0)
 		ereport(ERROR,