Fix situations in which instance actor can be set to a Mastodon-incompatible name (#22307)

* Validate internal actor

* Use “internal.actor” by default for the server actor username

* Fix instance actor username on the fly if it includes ':'

* Change actor name from internal.actor to mastodon.internal

1 files changed, 4 insertions, 2 deletions

diff --git a/app/models/concerns/account_finder_concern.rb b/app/models/concerns/account_finder_concern.rb
index e8b804934..37c3b8895 100644
--- a/app/models/concerns/account_finder_concern.rb
+++ b/app/models/concerns/account_finder_concern.rb
@@ -13,9 +13,11 @@ module AccountFinderConcern
     end
 
     def representative
-      Account.find(-99).tap(&:ensure_keys!)
+      actor = Account.find(-99).tap(&:ensure_keys!)
+      actor.update!(username: 'mastodon.internal') if actor.username.include?(':')
+      actor
     rescue ActiveRecord::RecordNotFound
-      Account.create!(id: -99, actor_type: 'Application', locked: true, username: Rails.configuration.x.local_domain)
+      Account.create!(id: -99, actor_type: 'Application', locked: true, username: 'mastodon.internal')
     end
 
     def find_local(username)