Comment 2 for bug 1642687

I'm currently working on a patch that would require the domain_id when registering an IdP. If not explicitly provided (existing code), the current plan is to map the IdP to a default 'Federated' domain. Which is what is currently happening (sort of), except the Federated domain is not a real domain. Now it will be.

The problem with automatically creating a new domain for every IdP is that it would likely be unexpected for the admin. Imagine you were creating and deleting IdPs and you now had a bunch of new domains and no idea where they belong or why they were created.