Validate units in date_trunc for infinity (#29)

Author: jkosh44

CONTRIBUTING.md

@@ -7,7 +7,7 @@ To execute all tests run:
 ```bash
 make
 make install
-mask installcheck
+make installcheck
 ```
 
 You must have a running PostgreSQL server and the default user must have `LOGIN` and `SUPERUSER` privileges.

src/pg_duration.c

@@ -722,12 +722,6 @@ duration_trunc(PG_FUNCTION_ARGS)
 	struct pg_itm tt,
 			   *tm = &tt;
 
-	if (DURATION_NOT_FINITE(duration))
-	{
-		result = duration;
-		PG_RETURN_DURATION(result);
-	}
-
 	lowunits = downcase_truncate_identifier(VARDATA_ANY(units),
 											VARSIZE_ANY_EXHDR(units),
 											false);
@@ -736,6 +730,33 @@ duration_trunc(PG_FUNCTION_ARGS)
 
 	if (type == UNITS)
 	{
+		if (DURATION_NOT_FINITE(duration))
+		{
+			/*
+			 * 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_HOUR:
+				case DTK_MINUTE:
+				case DTK_SECOND:
+				case DTK_MILLISEC:
+				case DTK_MICROSEC:
+					result = duration;
+					PG_RETURN_DURATION(result);
+					break;
+
+				default:
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("unit \"%s\" not supported for type duration",
+									lowunits)));
+					result = 0;
+			}
+		}
+
 		duration2itm(duration, tm);
 		switch (val)
 		{

test/expected/duration.out

@@ -723,113 +723,41 @@ SELECT f, d, date_trunc(f, d) FROM valid_fields, inf_table WHERE NOT isfinite(d)
 (10 rows)
 
 SELECT date_trunc('epoch', duration 'infinity');
- date_trunc 
-------------
- infinity
-(1 row)
-
+ERROR:  unit "epoch" not recognized for type duration
 SELECT date_trunc('millennium', duration 'infinity');
- date_trunc 
-------------
- infinity
-(1 row)
-
+ERROR:  unit "millennium" not supported for type duration
 SELECT date_trunc('century', duration 'infinity');
- date_trunc 
-------------
- infinity
-(1 row)
-
+ERROR:  unit "century" not supported for type duration
 SELECT date_trunc('decade', duration 'infinity');
- date_trunc 
-------------
- infinity
-(1 row)
-
+ERROR:  unit "decade" not supported for type duration
 SELECT date_trunc('year', duration 'infinity');
- date_trunc 
-------------
- infinity
-(1 row)
-
+ERROR:  unit "year" not supported for type duration
 SELECT date_trunc('quarter', duration 'infinity');
- date_trunc 
-------------
- infinity
-(1 row)
-
+ERROR:  unit "quarter" not supported for type duration
 SELECT date_trunc('month', duration 'infinity');
- date_trunc 
-------------
- infinity
-(1 row)
-
+ERROR:  unit "month" not supported for type duration
 SELECT date_trunc('week', duration 'infinity');
- date_trunc 
-------------
- infinity
-(1 row)
-
+ERROR:  unit "week" not supported for type duration
 SELECT date_trunc('day', duration 'infinity');
- date_trunc 
-------------
- infinity
-(1 row)
-
+ERROR:  unit "day" not supported for type duration
 SELECT date_trunc('epoch', duration '-infinity');
- date_trunc 
-------------
- -infinity
-(1 row)
-
+ERROR:  unit "epoch" not recognized for type duration
 SELECT date_trunc('millennium', duration '-infinity');
- date_trunc 
-------------
- -infinity
-(1 row)
-
+ERROR:  unit "millennium" not supported for type duration
 SELECT date_trunc('century', duration '-infinity');
- date_trunc 
-------------
- -infinity
-(1 row)
-
+ERROR:  unit "century" not supported for type duration
 SELECT date_trunc('decade', duration '-infinity');
- date_trunc 
-------------
- -infinity
-(1 row)
-
+ERROR:  unit "decade" not supported for type duration
 SELECT date_trunc('year', duration '-infinity');
- date_trunc 
-------------
- -infinity
-(1 row)
-
+ERROR:  unit "year" not supported for type duration
 SELECT date_trunc('quarter', duration '-infinity');
- date_trunc 
-------------
- -infinity
-(1 row)
-
+ERROR:  unit "quarter" not supported for type duration
 SELECT date_trunc('month', duration '-infinity');
- date_trunc 
-------------
- -infinity
-(1 row)
-
+ERROR:  unit "month" not supported for type duration
 SELECT date_trunc('week', duration '-infinity');
- date_trunc 
-------------
- -infinity
-(1 row)
-
+ERROR:  unit "week" not supported for type duration
 SELECT date_trunc('day', duration '-infinity');
- date_trunc 
-------------
- -infinity
-(1 row)
-
+ERROR:  unit "day" not supported for type duration
 -- date_part
 SELECT f, d, date_part(f, d) FROM valid_fields, inf_table WHERE NOT isfinite(d);
       f      |     d     | date_part 
@@ -997,7 +925,6 @@ ERROR:  duration out of range
 SELECT sum(d) FROM inf_table;
 ERROR:  duration out of range
 -- Overflow
--- This matches PostgreSQL semantics, but is probably incorrect.
 SELECT duration '9223372036854775807 us';
  duration 
 ----------

test/sql/duration.sql

@@ -349,7 +349,6 @@ SELECT max(d), min(d) FROM inf_table;
 SELECT avg(d) FROM inf_table;
 SELECT sum(d) FROM inf_table;
 -- Overflow
--- This matches PostgreSQL semantics, but is probably incorrect.
 SELECT duration '9223372036854775807 us';
 SELECT duration '-9223372036854775808 us';