Use the properly transformed RangeVar for expandTableLikeClause().

transformCreateStmt() adjusts the transformed statement's RangeVar
to specify the target schema explicitly, for the express reason
of making sure that auxiliary statements derived by parse
transformation operate on the right table.  But the refactoring
I did in commit 502898192 got this wrong and passed the untransformed
RangeVar to expandTableLikeClause().  This could lead to assertion
failures or weird misbehavior if the wrong table was accessed.

Per report from Alexander Lakhin.  Like the previous patch, back-patch
to all supported branches.

Discussion: https://postgr.es/m/05051f9d-b32b-cb35-6735-0e9f2ab86b5f@gmail.com

3 files changed, 40 insertions, 6 deletions

diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 4992c22bbbf..79aba2acbcb 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -995,6 +995,7 @@ ProcessUtilitySlow(ParseState *pstate,
 				{
 					List	   *stmts;
 					ListCell   *l;
+					RangeVar   *table_rv = NULL;
 
 					/* Run parse analysis ... */
 					stmts = transformCreateStmt((CreateStmt *) parsetree,
@@ -1007,11 +1008,15 @@ ProcessUtilitySlow(ParseState *pstate,
 
 						if (IsA(stmt, CreateStmt))
 						{
+							CreateStmt *cstmt = (CreateStmt *) stmt;
 							Datum		toast_options;
 							static char *validnsps[] = HEAP_RELOPT_NAMESPACES;
 
+							/* Remember transformed RangeVar for LIKE */
+							table_rv = cstmt->relation;
+
 							/* Create the table itself */
-							address = DefineRelation((CreateStmt *) stmt,
+							address = DefineRelation(cstmt,
 													 RELKIND_RELATION,
 													 InvalidOid, NULL,
 													 queryString);
@@ -1030,7 +1035,7 @@ ProcessUtilitySlow(ParseState *pstate,
 							 * table
 							 */
 							toast_options = transformRelOptions((Datum) 0,
-																((CreateStmt *) stmt)->options,
+																cstmt->options,
 																"toast",
 																validnsps,
 																true,
@@ -1044,12 +1049,17 @@ ProcessUtilitySlow(ParseState *pstate,
 						}
 						else if (IsA(stmt, CreateForeignTableStmt))
 						{
+							CreateForeignTableStmt *cstmt = (CreateForeignTableStmt *) stmt;
+
+							/* Remember transformed RangeVar for LIKE */
+							table_rv = cstmt->base.relation;
+
 							/* Create the table itself */
-							address = DefineRelation((CreateStmt *) stmt,
+							address = DefineRelation(&cstmt->base,
 													 RELKIND_FOREIGN_TABLE,
 													 InvalidOid, NULL,
 													 queryString);
-							CreateForeignTable((CreateForeignTableStmt *) stmt,
+							CreateForeignTable(cstmt,
 											   address.objectId);
 							EventTriggerCollectSimpleCommand(address,
 															 secondaryObject,
@@ -1064,10 +1074,11 @@ ProcessUtilitySlow(ParseState *pstate,
 							 * to-do list.
 							 */
 							TableLikeClause *like = (TableLikeClause *) stmt;
-							RangeVar   *rv = ((CreateStmt *) parsetree)->relation;
 							List	   *morestmts;
 
-							morestmts = expandTableLikeClause(rv, like);
+							Assert(table_rv != NULL);
+
+							morestmts = expandTableLikeClause(table_rv, like);
 							stmts = list_concat(stmts, morestmts);
 
 							/*
diff --git a/src/test/regress/expected/create_table_like.out b/src/test/regress/expected/create_table_like.out
index f9fad8457fb..4796373e2ee 100644
--- a/src/test/regress/expected/create_table_like.out
+++ b/src/test/regress/expected/create_table_like.out
@@ -421,6 +421,24 @@ CREATE TABLE inh_error2 (LIKE ctlt4 INCLUDING STORAGE) INHERITS (ctlt1);
 NOTICE:  merging column "a" with inherited definition
 ERROR:  column "a" has a storage parameter conflict
 DETAIL:  MAIN versus EXTENDED
+-- Check that LIKE isn't confused by a system catalog of the same name
+CREATE TABLE pg_attrdef (LIKE ctlt1 INCLUDING ALL);
+\d+ public.pg_attrdef
+                               Table "public.pg_attrdef"
+ Column | Type | Collation | Nullable | Default | Storage  | Stats target | Description 
+--------+------+-----------+----------+---------+----------+--------------+-------------
+ a      | text |           | not null |         | main     |              | A
+ b      | text |           |          |         | extended |              | B
+Indexes:
+    "pg_attrdef_pkey" PRIMARY KEY, btree (a)
+    "pg_attrdef_b_idx" btree (b)
+    "pg_attrdef_expr_idx" btree ((a || b))
+Check constraints:
+    "ctlt1_a_check" CHECK (length(a) > 2)
+Statistics objects:
+    "public"."pg_attrdef_a_b_stat" (ndistinct, dependencies, mcv) ON a, b FROM public.pg_attrdef
+
+DROP TABLE public.pg_attrdef;
 DROP TABLE ctlt1, ctlt2, ctlt3, ctlt4, ctlt12_storage, ctlt12_comments, ctlt1_inh, ctlt13_inh, ctlt13_like, ctlt_all, ctla, ctlb CASCADE;
 NOTICE:  drop cascades to table inhe
 /* LIKE with other relation kinds */
diff --git a/src/test/regress/sql/create_table_like.sql b/src/test/regress/sql/create_table_like.sql
index 9d00f4309fa..f3e5758e15f 100644
--- a/src/test/regress/sql/create_table_like.sql
+++ b/src/test/regress/sql/create_table_like.sql
@@ -163,6 +163,11 @@ SELECT s.stxname, objsubid, description FROM pg_description, pg_statistic_ext s
 CREATE TABLE inh_error1 () INHERITS (ctlt1, ctlt4);
 CREATE TABLE inh_error2 (LIKE ctlt4 INCLUDING STORAGE) INHERITS (ctlt1);
 
+-- Check that LIKE isn't confused by a system catalog of the same name
+CREATE TABLE pg_attrdef (LIKE ctlt1 INCLUDING ALL);
+\d+ public.pg_attrdef
+DROP TABLE public.pg_attrdef;
+
 DROP TABLE ctlt1, ctlt2, ctlt3, ctlt4, ctlt12_storage, ctlt12_comments, ctlt1_inh, ctlt13_inh, ctlt13_like, ctlt_all, ctla, ctlb CASCADE;