Added new logic to ACL system:
1) If GRANT OPTION (not mysql db):
Ok to update existing user, but not password.
Not allowed to make a new user.
2) If UPDATE_ACL to mysql DB:
Ok to update current user, but not make a new one.
3) If INSERT_ACL to mysql DB:
Ok to add a new user, but not modify existing.
4) If GRANT OPTION to mysql DB:
All modifications OK.
First one is related to Bug#7905. One should not be allowed to
create new user with password without UPDATE privilege to
MySQL database. Furthermore, executing the same GRANT statement
twice would actually crash the server and corrupt privilege database.
Other bug was that one could update a column, using the existing
value as basis to calculate the new value (e.g. UPDATE t1 SET a=a+1)
without SELECT privilege to the field (a in the above example)
Fixed tests grant.pl and grant2, which were wrong.
are not specified in an insert. Most of these changes are actually to
clean up the test suite to either specify defaults to avoid warnings,
or add the warnings to the results. Related to bug #5986.
he has SELECT and INSERT privileges for table with primary key"
Now we set lex->duplicates= DUP_UPDATE right in parser if INSERT has
ON DUPLICATE KEY UPDATE clause, this simplifies insert_precheck()
function (this also fixes a bug) and some other code.
'SHOW GRANTS' syntax is added
'SHOW GRANTS FOR CURRENT_USER' syntax is added
'SHOW GRANTS FOR CURRENT_USER()' syntax is added
CURRENT_USER without parens in expressions(SELECT CURRENT_USER;)
