Prevent ALTER TABLE ... MODIFY ... NOT NULL on columns for which there is a foreign key constraint ON ... SET NULL.  (Bug #25927)
Prevent ALTER TABLE ... MODIFY ... NOT NULL on columns for which
there is a foreign key constraint ON ... SET NULL.  (Bug #25927)

dict_foreign_find_index(): Add paramettter check_null.

dict_foreign_add_to_cache(): Do not allow ON DELETE SET NULL
or ON UPDATE SET NULL if any of the referencing columns are declared NOT NULL.


ollie314/server,slanterns/server,davidl-zend/zenddbi,natsys/mariadb_10.2,davidl-zend/zenddbi,natsys/mariadb_10.2,ollie314/server,flynn1973/mariadb-aix,davidl-zend/zenddbi,ollie314/server,ollie314/server,natsys/mariadb_10.2,flynn1973/mariadb-aix,natsys/mariadb_10.2,davidl-zend/zenddbi,ollie314/server,natsys/mariadb_10.2,flynn1973/mariadb-aix,ollie314/server,davidl-zend/zenddbi,davidl-zend/zenddbi,davidl-zend/zenddbi,davidl-zend/zenddbi,ollie314/server,ollie314/server,natsys/mariadb_10.2,ollie314/server,flynn1973/mariadb-aix,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,davidl-zend/zenddbi,natsys/mariadb_10.2,ollie314/server,flynn1973/mariadb-aix,flynn1973/mariadb-aix,davidl-zend/zenddbi,davidl-zend/zenddbi,natsys/mariadb_10.2,flynn1973/mariadb-aix,flynn1973/mariadb-aix,flynn1973/mariadb-aix,ollie314/server,flynn1973/mariadb-aix,flynn1973/mariadb-aix