Fix crash when using CALL on an aggregate

Author: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Reported-by: Rushabh Lathia <rushabh.lathia@gmail.com>

src/backend/parser/parse_func.c

@@ -336,6 +336,15 @@ ParseFuncOrColumn(ParseState *pstate, List *funcname, List *fargs,
 		Form_pg_aggregate classForm;
 		int			catDirectArgs;
 
+		if (proc_call)
+			ereport(ERROR,
+					(errcode(ERRCODE_UNDEFINED_FUNCTION),
+					 errmsg("%s is not a procedure",
+							func_signature_string(funcname, nargs,
+												  argnames,
+												  actual_arg_types)),
+					 parser_errposition(pstate, location)));
+
 		tup = SearchSysCache1(AGGFNOID, ObjectIdGetDatum(funcid));
 		if (!HeapTupleIsValid(tup)) /* should not happen */
 			elog(ERROR, "cache lookup failed for aggregate %u", funcid);

src/test/regress/expected/create_procedure.out

@@ -41,6 +41,15 @@ SELECT 5;
 $$;
 CALL ptest2();
 -- various error cases
+CALL version();  -- error: not a procedure
+ERROR:  version() is not a procedure
+LINE 1: CALL version();
+             ^
+HINT:  To call a function, use SELECT.
+CALL sum(1);  -- error: not a procedure
+ERROR:  sum(integer) is not a procedure
+LINE 1: CALL sum(1);
+             ^
 CREATE PROCEDURE ptestx() LANGUAGE SQL WINDOW AS $$ INSERT INTO cp_test VALUES (1, 'a') $$;
 ERROR:  invalid attribute in procedure definition
 LINE 1: CREATE PROCEDURE ptestx() LANGUAGE SQL WINDOW AS $$ INSERT I...

src/test/regress/sql/create_procedure.sql

@@ -30,6 +30,9 @@ CALL ptest2();
 
 -- various error cases
 
+CALL version();  -- error: not a procedure
+CALL sum(1);  -- error: not a procedure
+
 CREATE PROCEDURE ptestx() LANGUAGE SQL WINDOW AS $$ INSERT INTO cp_test VALUES (1, 'a') $$;
 CREATE PROCEDURE ptestx() LANGUAGE SQL STRICT AS $$ INSERT INTO cp_test VALUES (1, 'a') $$;
 CREATE PROCEDURE ptestx(OUT a int) LANGUAGE SQL AS $$ INSERT INTO cp_test VALUES (1, 'a') $$;