Transmogrifier: Save correct ids for incoming deletes.

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -409,7 +409,10 @@ def delete(%User{ap_id: ap_id, follower_address: follower_address} = user) do
     end
   end
 
-  def delete(%Object{data: %{"id" => id, "actor" => actor}} = object, local \\ true) do
+  def delete(%Object{data: %{"id" => id, "actor" => actor}} = object, options \\ []) do
+    local = Keyword.get(options, :local, true)
+    activity_id = Keyword.get(options, :activity_id, nil)
+
     user = User.get_cached_by_ap_id(actor)
     to = (object.data["to"] || []) ++ (object.data["cc"] || [])
 
@@ -420,7 +423,8 @@ def delete(%Object{data: %{"id" => id, "actor" => actor}} = object, local \\ tru
            "object" => id,
            "to" => to,
            "deleted_activity_id" => activity && activity.id
-         },
+         }
+         |> maybe_put("id", activity_id),
          {:ok, activity} <- insert(data, local, false),
          stream_out_participations(object, user),
          _ <- decrease_replies_count_if_reply(object),

lib/pleroma/web/activity_pub/transmogrifier.ex

@@ -637,7 +637,7 @@ def handle_incoming(
   # an error or a tombstone.  This would allow us to verify that a deletion actually took
   # place.
   def handle_incoming(
-        %{"type" => "Delete", "object" => object_id, "actor" => actor, "id" => _id} = data,
+        %{"type" => "Delete", "object" => object_id, "actor" => actor, "id" => id} = data,
         _options
       ) do
     object_id = Utils.get_ap_id(object_id)
@@ -646,7 +646,7 @@ def handle_incoming(
          {:ok, %User{} = actor} <- User.get_or_fetch_by_ap_id(actor),
          {:ok, object} <- get_obj_helper(object_id),
          :ok <- Containment.contain_origin(actor.ap_id, object.data),
-         {:ok, activity} <- ActivityPub.delete(object, false) do
+         {:ok, activity} <- ActivityPub.delete(object, local: false, activity_id: id) do
       {:ok, activity}
     else
       nil ->

test/web/activity_pub/transmogrifier_test.exs

@@ -696,8 +696,9 @@ test "it works for incoming deletes" do
         |> Map.put("object", object)
         |> Map.put("actor", activity.data["actor"])
 
-      {:ok, %Activity{local: false}} = Transmogrifier.handle_incoming(data)
+      {:ok, %Activity{local: false, data: %{"id" => id}}} = Transmogrifier.handle_incoming(data)
 
+      assert id == data["id"]
       refute Activity.get_by_id(activity.id)
     end