Now, not null fields are respected by the UTF-8 migration process. Also, for those NULLable fields, if the default was '', convert it to null (i.e. disable de default).
Now, not null fields are respected by the UTF-8 migration process. Also,
for those NULLable fields, if the default was '', convert it to null (i.e.
disable de default).

dilawar/moodle