partition-funcs-tweak.patch

diff --git a/src/backend/utils/adt/partitionfuncs.c b/src/backend/utils/adt/partitionfuncs.c
index 36d9f69cbc..a2fe4f34b6 100644
--- a/src/backend/utils/adt/partitionfuncs.c
+++ b/src/backend/utils/adt/partitionfuncs.c
@@ -35,17 +35,17 @@ static bool
 check_rel_can_be_partition(Oid relid)
 {
 	char		relkind;
+	bool		relispartition;
 
 	/* Check if relation exists */
 	if (!SearchSysCacheExists1(RELOID, ObjectIdGetDatum(relid)))
 		return false;
 
 	relkind = get_rel_relkind(relid);
+	relispartition = get_rel_relispartition(relid);
 
 	/* Only allow relation types that can appear in partition trees. */
-	if (relkind != RELKIND_RELATION &&
-		relkind != RELKIND_FOREIGN_TABLE &&
-		relkind != RELKIND_INDEX &&
+	if (!relispartition &&
 		relkind != RELKIND_PARTITIONED_TABLE &&
 		relkind != RELKIND_PARTITIONED_INDEX)
 		return false;
@@ -189,13 +189,6 @@ pg_partition_root(PG_FUNCTION_ARGS)
 	if (!check_rel_can_be_partition(relid))
 		PG_RETURN_NULL();
 
-	/*
-	 * If the relation is not a partition (it may be the partition parent),
-	 * return itself as a result.
-	 */
-	if (!get_rel_relispartition(relid))
-		PG_RETURN_OID(relid);
-
 	/* Fetch the top-most parent */
 	ancestors = get_partition_ancestors(relid);
 	rootrelid = llast_oid(ancestors);
diff --git a/src/test/regress/expected/partition_info.out b/src/test/regress/expected/partition_info.out
index 73269ffd09..24e3fe60f3 100644
--- a/src/test/regress/expected/partition_info.out
+++ b/src/test/regress/expected/partition_info.out
@@ -138,19 +138,18 @@ SELECT relid, parentrelid, level, isleaf
 (6 rows)
 
 DROP TABLE ptif_test;
--- Table that is not part of any partition tree is the only member listed.
+-- Table that is not part of any partition tree is not listed.
 CREATE TABLE ptif_normal_table(a int);
 SELECT relid, parentrelid, level, isleaf
   FROM pg_partition_tree('ptif_normal_table');
-       relid       | parentrelid | level | isleaf 
--------------------+-------------+-------+--------
- ptif_normal_table |             |     0 | t
-(1 row)
+ relid | parentrelid | level | isleaf 
+-------+-------------+-------+--------
+(0 rows)
 
 SELECT pg_partition_root('ptif_normal_table');
  pg_partition_root 
 -------------------
- ptif_normal_table
+ 
 (1 row)
 
 DROP TABLE ptif_normal_table;
diff --git a/src/test/regress/sql/partition_info.sql b/src/test/regress/sql/partition_info.sql
index 119b90afe4..d9dfa5d5d7 100644
--- a/src/test/regress/sql/partition_info.sql
+++ b/src/test/regress/sql/partition_info.sql
@@ -64,7 +64,7 @@ SELECT relid, parentrelid, level, isleaf
 
 DROP TABLE ptif_test;
 
--- Table that is not part of any partition tree is the only member listed.
+-- Table that is not part of any partition tree is not listed.
 CREATE TABLE ptif_normal_table(a int);
 SELECT relid, parentrelid, level, isleaf
   FROM pg_partition_tree('ptif_normal_table');