Bug#28318 (CREATE FUNCTION (UDF) requires a schema) -- part II

The root cause of the issue was that the CREATE FUNCTION grammar,
for User Defined Functions, was using the sp_name rule.
The sp_name rule is intended for fully qualified stored procedure names,
like either ident.ident, or just ident but with a default database
implicitly selected.

A UDF does not have a fully qualified name, only a name (ident), and should
not use the sp_name grammar fragment during parsing.

The fix is to re-organize the CREATE FUNCTION grammar, to better separate:
- creating UDF (no definer, can have AGGREGATE, simple ident)
- creating Stored Functions (definer, no AGGREGATE, fully qualified name)

With the test case provided, another issue was exposed which is also fixed:
the DROP FUNCTION statement was using sp_name and also failing when no database
is implicitly selected, when droping UDF functions.
The fix is also to change the grammar so that DROP FUNCTION works with
both the ident.ident syntax (to drop a stored function), or just the ident
syntax (to drop either a UDF or a Stored Function, in the current database)


mysql-test/r/sp-error.result:
  Adjust test results
mysql-test/r/udf.result:
  Adjust test results
mysql-test/t/sp-error.test:
  Adjust test results
mysql-test/t/udf.test:
  Adjust test results
sql/sql_parse.cc:
  CREATE UDF FUNCTION does not use a fully qualified name.
sql/sql_yacc.yy:
  Fix grammar for CREATE / DROP FUNCTION, FOR udf
  Improve error messages for select no_such_function()

1 files changed, 2 insertions, 2 deletions

diff --git a/mysql-test/r/sp-error.result b/mysql-test/r/sp-error.result
index cc217ecd093..b4bcfbdc7f7 100644
--- a/mysql-test/r/sp-error.result
+++ b/mysql-test/r/sp-error.result
@@ -1211,7 +1211,7 @@ ERROR 42S02: Unknown table 'c' in field list
 drop procedure bug15091;
 drop function if exists bug16896;
 create aggregate function bug16896() returns int return 1;
-ERROR 42000: AGGREGATE is not supported for stored functions
+ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '() returns int return 1' at line 1
 DROP PROCEDURE IF EXISTS bug14702;
 CREATE IF NOT EXISTS PROCEDURE bug14702()
 BEGIN
@@ -1457,7 +1457,7 @@ CREATE DATABASE mysqltest;
 USE mysqltest;
 DROP DATABASE mysqltest;
 SELECT inexistent(), 1 + ,;
-ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1
+ERROR 42000: FUNCTION inexistent does not exist
 SELECT inexistent();
 ERROR 42000: FUNCTION inexistent does not exist
 SELECT .inexistent();