Avoid allowing internal users to be invited as guests

Issue Summary

In order to invite a user to become a guest, a site administrator must use the Invite > Guests option from the user management or toggle the Guest access under the user's profile.

If a user already has internal access to Confluence, it will not be possible to toggle the Guest access under the user's profile and vice-versa, avoiding a user being both guest and an internal collaborator.

Even though the user is already an internal user, if the administrator uses the Invite > Guests option, it will bypass the restriction and allow the user to become both a guest and an internal user, which will trigger the following error message as soon as the invite is done and has the Configure space access pop-up:

Some users couldn't be added. Try searching for them, or refresh the page.

Steps to Reproduce

1. Invite a user and give the account application access to Confluence (internal).
2. Once the user is invited and has the application access, invite the same user as a guest via the Invite > Guests option from the user management.
3. Once the invite is finished, tap the Configure space access pop-up, which will redirect the admin to Confluence's Global permissions.

Expected Results

The user's profile and list of spaces should be displayed so the admin can pick a space and provide the guest with access to it.

Actual Results

The following error is displayed:

Additional notes

• In the global permissions pop-up, if the admin adds the invited user's name, an error message will be displayed:

Guests can only have access to one space at a time. <GUEST-USER> already has access to another space

* This behavior can also be replicated if:

• • The admin invites the user as a guest, but in the invitation flow, adds the user to an internal group of Confluence (I.E. confluence-users)
  • In the new administration experience, if the admin uses the option to invite as a guest and select User along with the Guest option for product roles.

Suggestion

To avoid such errors, this is a suggestion to:

• Under the invitation flow, have a message stating that the user is already an internal user and block it from being invited as a guest.
• If the user is still invited, provided a clear message in the space access pop-up, stating that the user is already an internal one and product access for Confluence should be removed.