Auto-complete for mentions in subwiki should only list global users with access

I have a sub-wiki, where I allow global and local users, but global users only on invitation by the admins.
When I type @ in a comment or in a page, the auto complete popup for the users to be mentioned appears.

Current behaviour: All local users and all global users are listed in the auto-complete popup.

Expected behaviour: Only the local users and those global users, that have access to the subwiki, are listed in the auto-complete popup.