Bugfix: email reassignment failure when deleting a person

If the person to be deleted had existing posts, updates happened in the
wrong order, causing foreign key violations.

Author: dutow

app/models/person.rb

@@ -98,9 +98,19 @@ def attach_alias!(alias_record, user: nil)
   def cleanup_orphaned_person(person)
     return if person.user.present?
     return if Alias.where(person_id: person.id).exists?
+    reassign_authored_records(person)
     person.destroy!
   end
 
+  def reassign_authored_records(old_person)
+    Topic.where(creator_person_id: old_person.id).update_all(creator_person_id: id)
+    Topic.where(last_sender_person_id: old_person.id).update_all(last_sender_person_id: id)
+    Message.where(sender_person_id: old_person.id).update_all(sender_person_id: id)
+    Mention.where(person_id: old_person.id).update_all(person_id: id)
+    TopicParticipant.where(person_id: old_person.id).where.not(topic_id: TopicParticipant.where(person_id: id).select(:topic_id)).update_all(person_id: id)
+    TopicParticipant.where(person_id: old_person.id).delete_all
+  end
+
   def merge_contributor_memberships_from(other_person)
     other_person.contributor_memberships.find_each do |membership|
       ContributorMembership.find_or_create_by!(person_id: id, contributor_type: membership.contributor_type) do |record|