Fix parse tree of DROP TRANSFORM and COMMENT ON TRANSFORM

The plain C string language name needs to be wrapped in makeString() so
that the parse tree is copyable.  This is detectable by
-DCOPY_PARSE_PLAN_TREES.  Add a test case for the COMMENT case.

Also make the quoting in the error messages more consistent.

discovered by Tom Lane

contrib/hstore_plperl/expected/create_transform.out

@@ -23,21 +23,22 @@ CREATE TRANSFORM FOR hstore LANGUAGE plperl (FROM SQL WITH FUNCTION internal_in(
 ERROR:  first argument of transform function must be type "internal"
 CREATE TRANSFORM FOR hstore LANGUAGE plperl (FROM SQL WITH FUNCTION hstore_to_plperl(internal), TO SQL WITH FUNCTION plperl_to_hstore(internal));  -- ok
 CREATE TRANSFORM FOR hstore LANGUAGE plperl (FROM SQL WITH FUNCTION hstore_to_plperl(internal), TO SQL WITH FUNCTION plperl_to_hstore(internal));  -- fail
-ERROR:  transform for type hstore language plperl already exists
+ERROR:  transform for type hstore language "plperl" already exists
 CREATE OR REPLACE TRANSFORM FOR hstore LANGUAGE plperl (FROM SQL WITH FUNCTION hstore_to_plperl(internal), TO SQL WITH FUNCTION plperl_to_hstore(internal));  -- ok
 CREATE OR REPLACE TRANSFORM FOR hstore LANGUAGE plperl (FROM SQL WITH FUNCTION hstore_to_plperl(internal));  -- ok
 CREATE OR REPLACE TRANSFORM FOR hstore LANGUAGE plperl (TO SQL WITH FUNCTION plperl_to_hstore(internal));  -- ok
+COMMENT ON TRANSFORM FOR hstore LANGUAGE plperl IS 'test';
 DROP TRANSFORM IF EXISTS FOR fake_type LANGUAGE plperl;
 NOTICE:  type "fake_type" does not exist, skipping
 DROP TRANSFORM IF EXISTS FOR hstore LANGUAGE fake_lang;
-NOTICE:  transform for type hstore language fake_lang does not exist, skipping
+NOTICE:  transform for type hstore language "fake_lang" does not exist, skipping
 DROP TRANSFORM FOR foo LANGUAGE plperl;
 ERROR:  type "foo" does not exist
 DROP TRANSFORM FOR hstore LANGUAGE foo;
 ERROR:  language "foo" does not exist
 DROP TRANSFORM FOR hstore LANGUAGE plperl;
 DROP TRANSFORM IF EXISTS FOR hstore LANGUAGE plperl;
-NOTICE:  transform for type hstore language plperl does not exist, skipping
+NOTICE:  transform for type hstore language "plperl" does not exist, skipping
 DROP FUNCTION hstore_to_plperl(val internal);
 DROP FUNCTION plperl_to_hstore(val internal);
 CREATE EXTENSION hstore_plperl;

contrib/hstore_plperl/sql/create_transform.sql

@@ -26,6 +26,8 @@ CREATE OR REPLACE TRANSFORM FOR hstore LANGUAGE plperl (FROM SQL WITH FUNCTION h
 CREATE OR REPLACE TRANSFORM FOR hstore LANGUAGE plperl (FROM SQL WITH FUNCTION hstore_to_plperl(internal));  -- ok
 CREATE OR REPLACE TRANSFORM FOR hstore LANGUAGE plperl (TO SQL WITH FUNCTION plperl_to_hstore(internal));  -- ok
 
+COMMENT ON TRANSFORM FOR hstore LANGUAGE plperl IS 'test';
+
 DROP TRANSFORM IF EXISTS FOR fake_type LANGUAGE plperl;
 DROP TRANSFORM IF EXISTS FOR hstore LANGUAGE fake_lang;
 DROP TRANSFORM FOR foo LANGUAGE plperl;

src/backend/catalog/objectaddress.c

@@ -770,7 +770,7 @@ get_object_address(ObjectType objtype, List *objname, List *objargs,
 			case OBJECT_TRANSFORM:
 				{
 					TypeName   *typename = (TypeName *) linitial(objname);
-					char	   *langname = (char *) linitial(objargs);
+					char	   *langname = strVal(linitial(objargs));
 					Oid			type_id = LookupTypeNameOid(NULL, typename, missing_ok);
 					Oid			lang_id = get_language_oid(langname, missing_ok);
 

src/backend/commands/dropcmds.c

@@ -369,9 +369,9 @@ does_not_exist_skipping(ObjectType objtype, List *objname, List *objargs)
 		case OBJECT_TRANSFORM:
 			if (!type_in_list_does_not_exist_skipping(objname, &msg, &name))
 			{
-				msg = gettext_noop("transform for type %s language %s does not exist, skipping");
+				msg = gettext_noop("transform for type %s language \"%s\" does not exist, skipping");
 				name = TypeNameToString((TypeName *) linitial(objname));
-				args = (char *) linitial(objargs);
+				args = strVal(linitial(objargs));
 			}
 			break;
 		case OBJECT_TRIGGER:

src/backend/commands/functioncmds.c

@@ -1867,7 +1867,7 @@ CreateTransform(CreateTransformStmt *stmt)
 		if (!stmt->replace)
 			ereport(ERROR,
 					(errcode(ERRCODE_DUPLICATE_OBJECT),
-					 errmsg("transform for type %s language %s already exists",
+					 errmsg("transform for type %s language \"%s\" already exists",
 							format_type_be(typeid),
 							stmt->lang)));
 

src/backend/parser/gram.y

@@ -4112,7 +4112,7 @@ AlterExtensionContentsStmt:
 					n->action = $4;
 					n->objtype = OBJECT_TRANSFORM;
 					n->objname = list_make1($7);
-					n->objargs = list_make1($9);
+					n->objargs = list_make1(makeString($9));
 					$$ = (Node *)n;
 				}
 			| ALTER EXTENSION name add_drop TYPE_P Typename
@@ -5773,7 +5773,7 @@ CommentStmt:
 					CommentStmt *n = makeNode(CommentStmt);
 					n->objtype = OBJECT_TRANSFORM;
 					n->objname = list_make1($5);
-					n->objargs = list_make1($7);
+					n->objargs = list_make1(makeString($7));
 					n->comment = $9;
 					$$ = (Node *) n;
 				}
@@ -7389,7 +7389,7 @@ DropTransformStmt: DROP TRANSFORM opt_if_exists FOR Typename LANGUAGE name opt_d
 					DropStmt *n = makeNode(DropStmt);
 					n->removeType = OBJECT_TRANSFORM;
 					n->objects = list_make1(list_make1($5));
-					n->arguments = list_make1(list_make1($7));
+					n->arguments = list_make1(list_make1(makeString($7)));
 					n->behavior = $8;
 					n->missing_ok = $3;
 					$$ = (Node *)n;