LDAP Authentication re-create global user locally

When a global user logs in locally, a new local user is created instead of updating the global user which has rights to the local xwiki. This seems to be related to the way findUser() search for existing user only the local database.

Moreover, restriction based on ldap.user_group applied locally, require global user to be also member of the locally defined ldap group to be able to log in. Do not know if this intended or not, but I do not feel this to be very practical since the only way I have got to avoid local user to login globally and create a user globally, is by restricting global and local login to different ldap group.