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/udf.result b/mysql-test/r/udf.result
index 3e29c780ca8..4a12e8e6d81 100644
--- a/mysql-test/r/udf.result
+++ b/mysql-test/r/udf.result
@@ -95,10 +95,10 @@ FR
 DROP TABLE bug19904;
 CREATE DEFINER=CURRENT_USER() FUNCTION should_not_parse
 RETURNS STRING SONAME "should_not_parse.so";
-ERROR HY000: Incorrect usage of SONAME and DEFINER
+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 STRING SONAME "should_not_parse.so"' at line 2
 CREATE DEFINER=someone@somewhere FUNCTION should_not_parse
 RETURNS STRING SONAME "should_not_parse.so";
-ERROR HY000: Incorrect usage of SONAME and DEFINER
+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 STRING SONAME "should_not_parse.so"' at line 2
 create table t1(f1 int);
 insert into t1 values(1),(2);
 explain select myfunc_int(f1) from t1 order by 1;