Improve handling of date_trunc() units for infinite input values

Previously, if an infinite value was passed to date_trunc(), then the
same infinite value would always be returned regardless of the field
unit given by the caller.  This commit updates the function so that an
error is returned when an invalid unit is passed to date_trunc() with an
infinite value.

This matches the behavior of date_trunc() with a finite value and
date_part() with an infinite value, making the handling of interval,
timestamp and timestamptz more consistent across the board for these two
functions.

Some tests are added to cover all these new failure cases, with an
unsupported unit and infinite values for the three data types.  There
were no test cases in core that checked all these patterns up to now.

Author: Joseph Koshakow
Discussion: https://postgr.es/m/CAAvxfHc4084dGzEJR0_pBZkDuqbPGc5wn7gK_M0XR_kRiCdUJQ@mail.gmail.com

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 18d7d8a108ac09ec41ee60ec539dc55f6eb2ce36..1b33eb6ea8db7d04b25b7ffe36442023522799ae 100644 (file)
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -4620,9 +4620,6 @@ timestamp_trunc(PG_FUNCTION_ARGS)
    struct pg_tm tt,
               *tm = &tt;
 
-   if (TIMESTAMP_NOT_FINITE(timestamp))
-       PG_RETURN_TIMESTAMP(timestamp);
-
    lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
                                            VARSIZE_ANY_EXHDR(units),
                                            false);
@@ -4631,6 +4628,39 @@ timestamp_trunc(PG_FUNCTION_ARGS)
 
    if (type == UNITS)
    {
+       if (TIMESTAMP_NOT_FINITE(timestamp))
+       {
+           /*
+            * Errors thrown here for invalid units should exactly match those
+            * below, else there will be unexpected discrepancies between
+            * finite- and infinite-input cases.
+            */
+           switch (val)
+           {
+               case DTK_WEEK:
+               case DTK_MILLENNIUM:
+               case DTK_CENTURY:
+               case DTK_DECADE:
+               case DTK_YEAR:
+               case DTK_QUARTER:
+               case DTK_MONTH:
+               case DTK_DAY:
+               case DTK_HOUR:
+               case DTK_MINUTE:
+               case DTK_SECOND:
+               case DTK_MILLISEC:
+               case DTK_MICROSEC:
+                   PG_RETURN_TIMESTAMP(timestamp);
+                   break;
+               default:
+                   ereport(ERROR,
+                           (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                            errmsg("unit \"%s\" not supported for type %s",
+                                   lowunits, format_type_be(TIMESTAMPOID))));
+                   result = 0;
+           }
+       }
+
        if (timestamp2tm(timestamp, NULL, tm, &fsec, NULL, NULL) != 0)
            ereport(ERROR,
                    (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
@@ -4836,6 +4866,40 @@ timestamptz_trunc_internal(text *units, TimestampTz timestamp, pg_tz *tzp)
 
    if (type == UNITS)
    {
+       if (TIMESTAMP_NOT_FINITE(timestamp))
+       {
+           /*
+            * Errors thrown here for invalid units should exactly match those
+            * below, else there will be unexpected discrepancies between
+            * finite- and infinite-input cases.
+            */
+           switch (val)
+           {
+               case DTK_WEEK:
+               case DTK_MILLENNIUM:
+               case DTK_CENTURY:
+               case DTK_DECADE:
+               case DTK_YEAR:
+               case DTK_QUARTER:
+               case DTK_MONTH:
+               case DTK_DAY:
+               case DTK_HOUR:
+               case DTK_MINUTE:
+               case DTK_SECOND:
+               case DTK_MILLISEC:
+               case DTK_MICROSEC:
+                   PG_RETURN_TIMESTAMPTZ(timestamp);
+                   break;
+
+               default:
+                   ereport(ERROR,
+                           (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                            errmsg("unit \"%s\" not supported for type %s",
+                                   lowunits, format_type_be(TIMESTAMPTZOID))));
+                   result = 0;
+           }
+       }
+
        if (timestamp2tm(timestamp, &tz, tm, &fsec, NULL, tzp) != 0)
            ereport(ERROR,
                    (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
@@ -4966,9 +5030,6 @@ timestamptz_trunc(PG_FUNCTION_ARGS)
    TimestampTz timestamp = PG_GETARG_TIMESTAMPTZ(1);
    TimestampTz result;
 
-   if (TIMESTAMP_NOT_FINITE(timestamp))
-       PG_RETURN_TIMESTAMPTZ(timestamp);
-
    result = timestamptz_trunc_internal(units, timestamp, session_timezone);
 
    PG_RETURN_TIMESTAMPTZ(result);
@@ -4986,13 +5047,6 @@ timestamptz_trunc_zone(PG_FUNCTION_ARGS)
    TimestampTz result;
    pg_tz      *tzp;
 
-   /*
-    * timestamptz_zone() doesn't look up the zone for infinite inputs, so we
-    * don't do so here either.
-    */
-   if (TIMESTAMP_NOT_FINITE(timestamp))
-       PG_RETURN_TIMESTAMP(timestamp);
-
    /*
     * Look up the requested timezone.
     */
@@ -5020,12 +5074,6 @@ interval_trunc(PG_FUNCTION_ARGS)
 
    result = (Interval *) palloc(sizeof(Interval));
 
-   if (INTERVAL_NOT_FINITE(interval))
-   {
-       memcpy(result, interval, sizeof(Interval));
-       PG_RETURN_INTERVAL_P(result);
-   }
-
    lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
                                            VARSIZE_ANY_EXHDR(units),
                                            false);
@@ -5034,6 +5082,41 @@ interval_trunc(PG_FUNCTION_ARGS)
 
    if (type == UNITS)
    {
+       if (INTERVAL_NOT_FINITE(interval))
+       {
+           /*
+            * Errors thrown here for invalid units should exactly match those
+            * below, else there will be unexpected discrepancies between
+            * finite- and infinite-input cases.
+            */
+           switch (val)
+           {
+               case DTK_MILLENNIUM:
+               case DTK_CENTURY:
+               case DTK_DECADE:
+               case DTK_YEAR:
+               case DTK_QUARTER:
+               case DTK_MONTH:
+               case DTK_DAY:
+               case DTK_HOUR:
+               case DTK_MINUTE:
+               case DTK_SECOND:
+               case DTK_MILLISEC:
+               case DTK_MICROSEC:
+                   memcpy(result, interval, sizeof(Interval));
+                   PG_RETURN_INTERVAL_P(result);
+                   break;
+
+               default:
+                   ereport(ERROR,
+                           (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+                            errmsg("unit \"%s\" not supported for type %s",
+                                   lowunits, format_type_be(INTERVALOID)),
+                            (val == DTK_WEEK) ? errdetail("Months usually have fractional weeks.") : 0));
+                   result = 0;
+           }
+       }
+
        interval2itm(*interval, tm);
        switch (val)
        {

diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index e5d919d0cf025e4d8963f8730b51bd3c6512f8f1..a16e3ccdb2ee1690205d7028f34cf76bd745cf47 100644 (file)
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -2219,6 +2219,15 @@ SELECT i AS interval, date_trunc('hour', i)
  -infinity | -infinity
 (2 rows)
 
+SELECT i AS interval, date_trunc('week', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ERROR:  unit "week" not supported for type interval
+DETAIL:  Months usually have fractional weeks.
+SELECT i AS interval, date_trunc('ago', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+ERROR:  unit "ago" not recognized for type interval
 SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
     FROM INFINITE_INTERVAL_TBL
     WHERE NOT isfinite(i);

diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index e287260051cecc4b5796ba27feb9dfaf70310482..6aaa19c8f4e4625d4ee83195b54f28d458dcb7f8 100644 (file)
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -591,6 +591,8 @@ SELECT date_trunc( 'week', timestamp '2004-02-29 15:44:17.71393' ) AS week_trunc
  Mon Feb 23 00:00:00 2004
 (1 row)
 
+SELECT date_trunc( 'ago', timestamp 'infinity' ) AS invalid_trunc;
+ERROR:  unit "ago" not recognized for type timestamp without time zone
 -- verify date_bin behaves the same as date_trunc for relevant intervals
 -- case 1: AD dates, origin < input
 SELECT

diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index b437613ac82e7cb9f12b7c45127af2ec29358292..a6dd45626ce6f1bfc6649efaa3cb4282a06cd86c 100644 (file)
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -701,6 +701,8 @@ SELECT date_trunc( 'week', timestamp with time zone '2004-02-29 15:44:17.71393'
  Mon Feb 23 00:00:00 2004 PST
 (1 row)
 
+SELECT date_trunc( 'ago', timestamp with time zone 'infinity' ) AS invalid_trunc;
+ERROR:  unit "ago" not recognized for type timestamp with time zone
 SELECT date_trunc('day', timestamp with time zone '2001-02-16 20:38:40+00', 'Australia/Sydney') as sydney_trunc;  -- zone name
          sydney_trunc         
 ------------------------------
@@ -719,6 +721,8 @@ SELECT date_trunc('day', timestamp with time zone '2001-02-16 20:38:40+00', 'VET
  Thu Feb 15 20:00:00 2001 PST
 (1 row)
 
+SELECT date_trunc('ago', timestamp with time zone 'infinity', 'GMT') AS invalid_zone_trunc;
+ERROR:  unit "ago" not recognized for type timestamp with time zone
 -- verify date_bin behaves the same as date_trunc for relevant intervals
 SELECT
   str,

diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 55054ae65d16f44fddb6d486c1f4c9665d0a647f..43bc793925ee5686e2ce1ec7ed126f1cbc80a124 100644 (file)
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -776,6 +776,14 @@ SELECT i AS interval, date_trunc('hour', i)
     FROM INFINITE_INTERVAL_TBL
     WHERE NOT isfinite(i);
 
+SELECT i AS interval, date_trunc('week', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
+SELECT i AS interval, date_trunc('ago', i)
+    FROM INFINITE_INTERVAL_TBL
+    WHERE NOT isfinite(i);
+
 SELECT i AS interval, justify_days(i), justify_hours(i), justify_interval(i)
     FROM INFINITE_INTERVAL_TBL
     WHERE NOT isfinite(i);

diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index 748469576d838525f0338cacfb0fe4fc454cf110..55f80530ea05efc8829ea18ffbe08bbe0c41ea4b 100644 (file)
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -176,6 +176,8 @@ SELECT d1 - timestamp without time zone '1997-01-02' AS diff
 
 SELECT date_trunc( 'week', timestamp '2004-02-29 15:44:17.71393' ) AS week_trunc;
 
+SELECT date_trunc( 'ago', timestamp 'infinity' ) AS invalid_trunc;
+
 -- verify date_bin behaves the same as date_trunc for relevant intervals
 
 -- case 1: AD dates, origin < input

diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index 6b91e7eddc787c38b447da6633aa0eb6d12687b4..a92586c363e20b94432ca9a17f10fb5623dea074 100644 (file)
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -200,10 +200,14 @@ SELECT d1 - timestamp with time zone '1997-01-02' AS diff
    FROM TIMESTAMPTZ_TBL WHERE d1 BETWEEN '1902-01-01' AND '2038-01-01';
 
 SELECT date_trunc( 'week', timestamp with time zone '2004-02-29 15:44:17.71393' ) AS week_trunc;
+SELECT date_trunc( 'ago', timestamp with time zone 'infinity' ) AS invalid_trunc;
 
 SELECT date_trunc('day', timestamp with time zone '2001-02-16 20:38:40+00', 'Australia/Sydney') as sydney_trunc;  -- zone name
 SELECT date_trunc('day', timestamp with time zone '2001-02-16 20:38:40+00', 'GMT') as gmt_trunc;  -- fixed-offset abbreviation
 SELECT date_trunc('day', timestamp with time zone '2001-02-16 20:38:40+00', 'VET') as vet_trunc;  -- variable-offset abbreviation
+SELECT date_trunc('ago', timestamp with time zone 'infinity', 'GMT') AS invalid_zone_trunc;
+
+
 
 -- verify date_bin behaves the same as date_trunc for relevant intervals
 SELECT