ActivityPub / Transmogrifier: Correctly store incoming Update id.

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -17,6 +17,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
   alias Pleroma.User
   alias Pleroma.Web.ActivityPub.MRF
   alias Pleroma.Web.ActivityPub.Transmogrifier
+  alias Pleroma.Web.ActivityPub.Utils
   alias Pleroma.Web.Streamer
   alias Pleroma.Web.WebFinger
 
@@ -270,8 +271,8 @@ def reject(%{to: to, actor: actor, object: object} = params) do
   end
 
   def update(%{to: to, cc: cc, actor: actor, object: object} = params) do
-    # only accept false as false value
     local = !(params[:local] == false)
+    activity_id = params[:activity_id]
 
     with data <- %{
            "to" => to,
@@ -280,6 +281,7 @@ def update(%{to: to, cc: cc, actor: actor, object: object} = params) do
            "actor" => actor,
            "object" => object
          },
+         data <- Utils.maybe_put(data, "id", activity_id),
          {:ok, activity} <- insert(data, local),
          :ok <- maybe_federate(activity) do
       {:ok, activity}

lib/pleroma/web/activity_pub/transmogrifier.ex

@@ -621,7 +621,8 @@ def handle_incoming(
         to: data["to"] || [],
         cc: data["cc"] || [],
         object: object,
-        actor: actor_id
+        actor: actor_id,
+        activity_id: data["id"]
       })
     else
       e ->

lib/pleroma/web/activity_pub/utils.ex

@@ -728,6 +728,6 @@ def get_existing_votes(actor, %{data: %{"id" => id}}) do
     |> Repo.all()
   end
 
-  defp maybe_put(map, _key, nil), do: map
-  defp maybe_put(map, key, value), do: Map.put(map, key, value)
+  def maybe_put(map, _key, nil), do: map
+  def maybe_put(map, key, value), do: Map.put(map, key, value)
 end

test/web/activity_pub/transmogrifier_test.exs

@@ -516,6 +516,8 @@ test "it works for incoming update activities" do
 
       {:ok, %Activity{data: data, local: false}} = Transmogrifier.handle_incoming(update_data)
 
+      assert data["id"] == update_data["id"]
+
       user = User.get_cached_by_ap_id(data["actor"])
       assert user.name == "gargle"