Bug #16896 Stored function: unused AGGREGATE-clause in CREATE FUNCTION

Description:
MySQL does not support aggregate stored functions, however the parser
allows AGGREGATE-clause in CREATE FUNCTION statement. This clause
is meaningless, i.e. it does not affect the definition.

How to repeat:
mysql> CREATE AGGREGATE FUNCTION f1() RETURNS INT RETURN 1;
Query OK, 0 rows affected (0.01 sec)

mysql> SELECT * FROM mysql.proc;
+------+------+----------+---------------+----------+-----------------+------------------+---------------+------------+---------+----------+----------------+---------------------+---------------------+----------+---------+
| db   | name | type     | specific_name | language | sql_data_access | is_deterministic | security_type | param_list | returns | body     | definer        | created             | modified            | sql_mode | comment |
+------+------+----------+---------------+----------+-----------------+------------------+---------------+------------+---------+----------+----------------+---------------------+---------------------+----------+---------+
| test | f1   | FUNCTION | f1            | SQL      | CONTAINS_SQL    | NO               | DEFINER       |            | int(11) | RETURN 1 | root@localhost | 2006-01-30 14:39:00 | 2006-01-30 14:39:00 |          |         |
+------+------+----------+---------------+----------+-----------------+------------------+---------------+------------+---------+----------+----------------+---------------------+---------------------+----------+---------+
1 row in set (0.00 sec)

mysql> SHOW CREATE FUNCTION f1;
+----------+----------+-------------------------------------------------+
| Function | sql_mode | Create Function                                 |
+----------+----------+-------------------------------------------------+
| f1       |          | CREATE FUNCTION `f1`() RETURNS int(11)
RETURN 1 |
+----------+----------+-------------------------------------------------+
1 row in set (0.00 sec)

mysql> SELECT * FROM information_schema.routines;
+---------------+-----------------+----------------+--------------+--------------+----------------+--------------+--------------------+---------------+-------------------+-----------------+------------------+-----------------+----------+---------------+---------------------+---------------------+----------+-----------------+----------------+
| SPECIFIC_NAME | ROUTINE_CATALOG | ROUTINE_SCHEMA | ROUTINE_NAME | ROUTINE_TYPE | DTD_IDENTIFIER | ROUTINE_BODY | ROUTINE_DEFINITION | EXTERNAL_NAME | EXTERNAL_LANGUAGE | PARAMETER_STYLE | IS_DETERMINISTIC | SQL_DATA_ACCESS | SQL_PATH | SECURITY_TYPE | CREATED             | LAST_ALTERED        | SQL_MODE | ROUTINE_COMMENT | DEFINER        |
+---------------+-----------------+----------------+--------------+--------------+----------------+--------------+--------------------+---------------+-------------------+-----------------+------------------+-----------------+----------+---------------+---------------------+---------------------+----------+-----------------+----------------+
| f1            | NULL            | test           | f1           | FUNCTION     | int(11)        | SQL          | RETURN 1           | NULL          | NULL              | SQL             | NO               | CONTAINS SQL    | NULL     | DEFINER       | 2006-01-30 14:39:00 | 2006-01-30 14:39:00 |          |                 | root@localhost |
+---------------+-----------------+----------------+--------------+--------------+----------------+--------------+--------------------+---------------+-------------------+-----------------+------------------+-----------------+----------+---------------+---------------------+---------------------+----------+-----------------+----------------+
1 row in set (0.01 sec)

Suggested fix:
Prohibit AGGREGATE-clause in CREATE FUNCTION statement.

A patch for this bug has been committed. After review, it may
be pushed to the relevant source trees for release in the next
version. You can access the patch from:

  http://lists.mysql.com/commits/2359

Approved by email (ok to push).

Pushed to bk 5.0.19.

"CREATE AGGREGATE FUNCTION p(...) ..."  (i.e. not an UDF), now gives the error message:
"ERROR 42000: AGGREGATE is not supported for stored functions"

Noted in 5.0.19 changelog.

The parser allowed <literal>CREATE AGGREGATE
FUNCTION</literal> for creating stored functions, even though
<literal>AGGREGATE</literal> does not apply. (It is used only
for <literal>CREATE FUNCTION</literal> only when creating
user-defined functions.) (Bug #16896)