Comment 1 for bug 1285138

Consistency sounds good to me.

From the pure UI side, it looks like this could simply be a matter of calling the default option "No default project", give it a specific fake id and check for that before attempting to update the default project.

https://github.com/openstack/horizon/blob/ac0ccc8e06/openstack_dashboard/dashboards/admin/users/forms.py#L53

We'll also need to update the user_update() API call to avoid always trying to update the default tenant no matter what:

https://github.com/openstack/horizon/blob/ac0ccc8e06/openstack_dashboard/api/keystone.py#L337