Use the properly transformed RangeVar for expandTableLikeClause().

tglsfdc · tglsfdc · commit 86b8ef139457 · 2020-09-13T12:51:21.000-04:00
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 5028981 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
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
@@ -949,6 +949,7 @@ ProcessUtilitySlow(Node *parsetree,
 				{
 					List	   *stmts;
 					ListCell   *l;
+					RangeVar   *table_rv = NULL;
 
 					/* Run parse analysis ... */
 					stmts = transformCreateStmt((CreateStmt *) parsetree,
@@ -961,11 +962,15 @@ ProcessUtilitySlow(Node *parsetree,
 
 						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);
 							EventTriggerCollectSimpleCommand(address,
@@ -983,7 +988,7 @@ ProcessUtilitySlow(Node *parsetree,
 							 * table
 							 */
 							toast_options = transformRelOptions((Datum) 0,
-											  ((CreateStmt *) stmt)->options,
+																cstmt->options,
 																"toast",
 																validnsps,
 																true,
@@ -997,11 +1002,16 @@ ProcessUtilitySlow(Node *parsetree,
 						}
 						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);
-							CreateForeignTable((CreateForeignTableStmt *) stmt,
+							CreateForeignTable(cstmt,
 											   address.objectId);
 							EventTriggerCollectSimpleCommand(address,
 															 secondaryObject,
@@ -1016,10 +1026,11 @@ ProcessUtilitySlow(Node *parsetree,
 							 * 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
@@ -243,6 +243,22 @@ 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 | Modifiers | 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)
+
+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
@@ -112,6 +112,11 @@ SELECT c.relname, objsubid, description FROM pg_description, pg_index i, pg_clas
 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;
 
 
