In case if the view mysql.user was created (e.g. in 10.6) with a
pre- 18edb0959f server with an unexpected
character_set_client or collation_connection, e.g.
utf8mb3 and utf8mb3_general_ci, mysql_upgrade did not fix it to the
expected latin1 and latin1_swedish_ci.
Since 11.8 this could often lead to "Illegax mix of collations" errors
when querying mysql.user, because since 11.8 the default collation for
utf8mb3 is utf8mb3_uca1400_ai_ci, according to the default
@@character_set_collations. For consistency, it's better to fix the
problem starting from 11.4.
For example:
MariaDB [test]> select user,host,is_role from
-> mysql.user where is_role='N';
ERROR 1267 (HY000): Illegal mix of collations (utf8mb3_general_ci,COERCIBLE)
and (utf8mb3_uca1400_ai_ci,COERCIBLE) for operation '='
Fixing mariadb_system_tables_fix.sql to drop the view if it has non-standard
character set or collations, so it gets recreated again correctly by
the CREATE statement in mariadb_system_tables.sql
ae5c8bfe76