ActivityPub: Fix deletes being exempt from MRF

Closes #1461

lib/pleroma/activity.ex

@@ -241,9 +241,10 @@ defmodule Pleroma.Activity do
   def normalize(ap_id) when is_binary(ap_id), do: get_by_ap_id_with_object(ap_id)
   def normalize(_), do: nil
 
-  def delete_by_ap_id(id) when is_binary(id) do
+  def delete_all_by_object_ap_id(id) when is_binary(id) do
     id
     |> Queries.by_object_id()
+    |> Queries.exclude_type("Delete")
     |> select([u], u)
     |> Repo.delete_all()
     |> elem(1)
@@ -255,7 +256,7 @@ defmodule Pleroma.Activity do
     |> purge_web_resp_cache()
   end
 
-  def delete_by_ap_id(_), do: nil
+  def delete_all_by_object_ap_id(_), do: nil
 
   defp purge_web_resp_cache(%Activity{} = activity) do
     %{path: path} = URI.parse(activity.data["id"])

lib/pleroma/activity/queries.ex

@@ -64,4 +64,12 @@ defmodule Pleroma.Activity.Queries do
       where: fragment("(?)->>'type' = ?", activity.data, ^activity_type)
     )
   end
+
+  @spec exclude_type(query, String.t()) :: query
+  def exclude_type(query \\ Activity, activity_type) do
+    from(
+      activity in query,
+      where: fragment("(?)->>'type' != ?", activity.data, ^activity_type)
+    )
+  end
 end

lib/pleroma/object.ex

@@ -147,7 +147,7 @@ defmodule Pleroma.Object do
 
   def delete(%Object{data: %{"id" => id}} = object) do
     with {:ok, _obj} = swap_object_with_tombstone(object),
-         deleted_activity = Activity.delete_by_ap_id(id),
+         deleted_activity = Activity.delete_all_by_object_ap_id(id),
          {:ok, true} <- Cachex.del(:object_cache, "object:#{id}"),
          {:ok, _} <- Cachex.del(:web_resp_cache, URI.parse(id).path) do
       {:ok, object, deleted_activity}

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -456,17 +456,18 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     user = User.get_cached_by_ap_id(actor)
     to = (object.data["to"] || []) ++ (object.data["cc"] || [])
 
-    with {:ok, object, activity} <- Object.delete(object),
+    with create_activity <- Activity.get_create_by_object_ap_id(id),
          data <-
            %{
              "type" => "Delete",
              "actor" => actor,
              "object" => id,
              "to" => to,
-             "deleted_activity_id" => activity && activity.id
+             "deleted_activity_id" => create_activity && create_activity.id
            }
            |> maybe_put("id", activity_id),
          {:ok, activity} <- insert(data, local, false),
+         {:ok, object, _create_activity} <- Object.delete(object),
          stream_out_participations(object, user),
          _ <- decrease_replies_count_if_reply(object),
          {:ok, _actor} <- decrease_note_count_if_public(user, object),