2 files changed, 47 insertions, 0 deletions
diff --git a/src/test/regress/expected/subselect.out b/src/test/regress/expected/subselect.out
index 9eecdc1e924..2d35de3fad6 100644
--- a/src/test/regress/expected/subselect.out
+++ b/src/test/regress/expected/subselect.out
@@ -1722,6 +1722,35 @@ fetch backward all in c1;
 
 commit;
 --
+-- Verify that we correctly flatten cases involving a subquery output
+-- expression that doesn't need to be wrapped in a PlaceHolderVar
+--
+explain (costs off)
+select tname, attname from (
+select relname::information_schema.sql_identifier as tname, * from
+  (select * from pg_class c) ss1) ss2
+  right join pg_attribute a on a.attrelid = ss2.oid
+where tname = 'tenk1' and attnum = 1;
+                                QUERY PLAN                                
+--------------------------------------------------------------------------
+ Nested Loop
+   ->  Index Scan using pg_class_relname_nsp_index on pg_class c
+         Index Cond: (relname = 'tenk1'::name)
+   ->  Index Scan using pg_attribute_relid_attnum_index on pg_attribute a
+         Index Cond: ((attrelid = c.oid) AND (attnum = 1))
+(5 rows)
+
+select tname, attname from (
+select relname::information_schema.sql_identifier as tname, * from
+  (select * from pg_class c) ss1) ss2
+  right join pg_attribute a on a.attrelid = ss2.oid
+where tname = 'tenk1' and attnum = 1;
+ tname | attname 
+-------+---------
+ tenk1 | unique1
+(1 row)
+
+--
 -- Tests for CTE inlining behavior
 --
 -- Basic subquery that can be inlined
diff --git a/src/test/regress/sql/subselect.sql b/src/test/regress/sql/subselect.sql
index 75a9b718b2f..af6e157aca0 100644
--- a/src/test/regress/sql/subselect.sql
+++ b/src/test/regress/sql/subselect.sql
@@ -891,6 +891,24 @@ fetch backward all in c1;
 commit;
 
 --
+-- Verify that we correctly flatten cases involving a subquery output
+-- expression that doesn't need to be wrapped in a PlaceHolderVar
+--
+
+explain (costs off)
+select tname, attname from (
+select relname::information_schema.sql_identifier as tname, * from
+  (select * from pg_class c) ss1) ss2
+  right join pg_attribute a on a.attrelid = ss2.oid
+where tname = 'tenk1' and attnum = 1;
+
+select tname, attname from (
+select relname::information_schema.sql_identifier as tname, * from
+  (select * from pg_class c) ss1) ss2
+  right join pg_attribute a on a.attrelid = ss2.oid
+where tname = 'tenk1' and attnum = 1;
+
+--
 -- Tests for CTE inlining behavior
 --