Prevent multiple handlers for Delete of Actor from running (#9292)

app/lib/activitypub/activity.rb

@@ -129,4 +129,10 @@ class ActivityPub::Activity
       ::FetchRemoteStatusService.new.call(@object['url'])
     end
   end
+
+  def lock_or_return(key, expire_after = 7.days.seconds)
+    yield if redis.set(key, true, nx: true, ex: expire_after)
+  ensure
+    redis.del(key)
+  end
 end

app/lib/activitypub/activity/delete.rb

@@ -12,9 +12,11 @@ class ActivityPub::Activity::Delete < ActivityPub::Activity
   private
 
   def delete_person
+    lock_or_return("delete_in_progress:#{@account.id}") do
       SuspendAccountService.new.call(@account)
       @account.destroy!
     end
+  end
 
   def delete_note
     return if object_uri.nil?