Add basic incoming deletions.

lib/pleroma/activity.ex

@@ -15,9 +15,13 @@ defmodule Pleroma.Activity do
       where: fragment("(?)->>'id' = ?", activity.data, ^to_string(ap_id)))
   end
 
+  def all_by_object_ap_id_q(ap_id) do
+    from activity in Activity,
+      where: fragment("(?)->'object'->>'id' = ?", activity.data, ^to_string(ap_id))
+  end
+
   def all_by_object_ap_id(ap_id) do
-    Repo.all(from activity in Activity,
-      where: fragment("(?)->'object'->>'id' = ?", activity.data, ^to_string(ap_id)))
+    Repo.all(all_by_object_ap_id_q(ap_id))
   end
 
   def get_create_activity_by_object_ap_id(ap_id) do

lib/pleroma/web/ostatus/handlers/delete_handler.ex

@@ -0,0 +1,14 @@
+defmodule Pleroma.Web.OStatus.DeleteHandler do
+  require Logger
+  alias Pleroma.Web.{XML, OStatus}
+  alias Pleroma.{Activity, Object, Repo}
+
+  def handle_delete(entry, doc \\ nil) do
+    with id <- XML.string_from_xpath("//id", entry),
+         object when not is_nil(object) <- Object.get_by_ap_id(id) do
+      Repo.delete(object)
+      Repo.delete_all(Activity.all_by_object_ap_id_q(id))
+      nil
+    end
+  end
+end

lib/pleroma/web/ostatus/ostatus.ex

@@ -9,7 +9,7 @@ defmodule Pleroma.Web.OStatus do
   alias Pleroma.Web.ActivityPub.ActivityPub
   alias Pleroma.Web.ActivityPub.Utils
   alias Pleroma.Web.{WebFinger, Websub}
-  alias Pleroma.Web.OStatus.{FollowHandler, NoteHandler}
+  alias Pleroma.Web.OStatus.{FollowHandler, NoteHandler, DeleteHandler}
 
   def feed_path(user) do
     "#{user.ap_id}/feed.atom"
@@ -34,6 +34,8 @@ defmodule Pleroma.Web.OStatus do
 
       try do
         case verb do
+          'http://activitystrea.ms/schema/1.0/delete' ->
+            with {:ok, activity} <- DeleteHandler.handle_delete(entry, doc), do: activity
           'http://activitystrea.ms/schema/1.0/follow' ->
             with {:ok, activity} <- FollowHandler.handle(entry, doc), do: activity
           'http://activitystrea.ms/schema/1.0/share' ->