Inline object when Announcing a self-owned private object

lib/pleroma/web/activity_pub/transmogrifier.ex

@@ -830,6 +830,27 @@ def prepare_outgoing(%{"type" => activity_type, "object" => object_id} = data)
     {:ok, data}
   end
 
+  def prepare_outgoing(%{"type" => "Announce", "actor" => ap_id, "object" => object_id} = data) do
+    object =
+      object_id
+      |> Object.normalize()
+
+    data =
+      if Visibility.is_private?(object) && object.data["actor"] == ap_id do
+        data |> Map.put("object", object |> Map.get(:data) |> prepare_object)
+      else
+        data |> maybe_fix_object_url
+      end
+
+    data =
+      data
+      |> strip_internal_fields
+      |> Map.merge(Utils.make_json_ld_header())
+      |> Map.delete("bcc")
+
+    {:ok, data}
+  end
+
   # Mastodon Accept/Reject requires a non-normalized object containing the actor URIs,
   # because of course it does.
   def prepare_outgoing(%{"type" => "Accept"} = data) do

test/web/activity_pub/transmogrifier_test.exs

@@ -1076,6 +1076,20 @@ test "it accepts Flag activities" do
   end
 
   describe "prepare outgoing" do
+    test "it inlines private announced objects" do
+      user = insert(:user)
+
+      {:ok, activity} = CommonAPI.post(user, %{"status" => "hey", "visibility" => "private"})
+
+      {:ok, announce_activity, _} = CommonAPI.repeat(activity.id, user)
+
+      {:ok, modified} = Transmogrifier.prepare_outgoing(announce_activity.data)
+      object = modified["object"]
+
+      assert modified["object"]["content"] == "hey"
+      assert modified["object"]["actor"] == modified["object"]["attributedTo"]
+    end
+
     test "it turns mentions into tags" do
       user = insert(:user)
       other_user = insert(:user)