Make MRF Keyword history-aware

lib/pleroma/object/updater.ex

@@ -197,4 +197,44 @@ defmodule Pleroma.Object.Updater do
       used_history_in_new_object?: used_history_in_new_object?
     }
   end
+
+  defp for_each_history_item(%{"orderedItems" => items} = history, _object, fun) do
+    new_items =
+      Enum.map(items, fun)
+      |> Enum.reduce_while(
+        {:ok, []},
+        fn
+          {:ok, item}, {:ok, acc} -> {:cont, {:ok, acc ++ [item]}}
+          e, _acc -> {:halt, e}
+        end
+      )
+
+    case new_items do
+      {:ok, items} -> {:ok, Map.put(history, "orderedItems", items)}
+      e -> e
+    end
+  end
+
+  defp for_each_history_item(history, _, _) do
+    {:ok, history}
+  end
+
+  def do_with_history(object, fun) do
+    with history <- object["formerRepresentations"],
+         object <- Map.drop(object, ["formerRepresentations"]),
+         {_, {:ok, object}} <- {:main_body, fun.(object)},
+         {_, {:ok, history}} <- {:history_items, for_each_history_item(history, object, fun)} do
+      object =
+        if history do
+          Map.put(object, "formerRepresentations", history)
+        else
+          object
+        end
+
+      {:ok, object}
+    else
+      {:main_body, e} -> e
+      {:history_items, e} -> e
+    end
+  end
 end

lib/pleroma/web/activity_pub/mrf/keyword_policy.ex

@@ -27,24 +27,46 @@ defmodule Pleroma.Web.ActivityPub.MRF.KeywordPolicy do
   end
 
   defp check_reject(%{"object" => %{} = object} = message) do
-    payload = object_payload(object)
+    with {:ok, _new_object} <-
+           Pleroma.Object.Updater.do_with_history(object, fn object ->
+             payload = object_payload(object)
 
-    if Enum.any?(Pleroma.Config.get([:mrf_keyword, :reject]), fn pattern ->
-         string_matches?(payload, pattern)
-       end) do
-      {:reject, "[KeywordPolicy] Matches with rejected keyword"}
-    else
+             if Enum.any?(Pleroma.Config.get([:mrf_keyword, :reject]), fn pattern ->
+                  string_matches?(payload, pattern)
+                end) do
+               {:reject, "[KeywordPolicy] Matches with rejected keyword"}
+             else
+               {:ok, message}
+             end
+           end) do
       {:ok, message}
+    else
+      e -> e
     end
   end
 
-  defp check_ftl_removal(%{"to" => to, "object" => %{} = object} = message) do
-    payload = object_payload(object)
+  defp check_ftl_removal(%{"type" => "Create", "to" => to, "object" => %{} = object} = message) do
+    check_keyword = fn object ->
+      payload = object_payload(object)
 
-    if Pleroma.Constants.as_public() in to and
-         Enum.any?(Pleroma.Config.get([:mrf_keyword, :federated_timeline_removal]), fn pattern ->
+      if Enum.any?(Pleroma.Config.get([:mrf_keyword, :federated_timeline_removal]), fn pattern ->
            string_matches?(payload, pattern)
          end) do
+        {:should_delist, nil}
+      else
+        {:ok, %{}}
+      end
+    end
+
+    should_delist? = fn object ->
+      with {:ok, _} <- Pleroma.Object.Updater.do_with_history(object, check_keyword) do
+        false
+      else
+        _ -> true
+      end
+    end
+
+    if Pleroma.Constants.as_public() in to and should_delist?.(object) do
       to = List.delete(to, Pleroma.Constants.as_public())
       cc = [Pleroma.Constants.as_public() | message["cc"] || []]
 
@@ -59,8 +81,12 @@ defmodule Pleroma.Web.ActivityPub.MRF.KeywordPolicy do
     end
   end
 
+  defp check_ftl_removal(message) do
+    {:ok, message}
+  end
+
   defp check_replace(%{"object" => %{} = object} = message) do
-    object =
+    replace_kw = fn object ->
       ["content", "name", "summary"]
       |> Enum.filter(fn field -> Map.has_key?(object, field) && object[field] end)
       |> Enum.reduce(object, fn field, object ->
@@ -73,6 +99,10 @@ defmodule Pleroma.Web.ActivityPub.MRF.KeywordPolicy do
 
         Map.put(object, field, data)
       end)
+      |> (fn object -> {:ok, object} end).()
+    end
+
+    {:ok, object} = Pleroma.Object.Updater.do_with_history(object, replace_kw)
 
     message = Map.put(message, "object", object)
 
@@ -80,7 +110,8 @@ defmodule Pleroma.Web.ActivityPub.MRF.KeywordPolicy do
   end
 
   @impl true
-  def filter(%{"type" => "Create", "object" => %{"content" => _content}} = message) do
+  def filter(%{"type" => type, "object" => %{"content" => _content}} = message)
+      when type in ["Create", "Update"] do
     with {:ok, message} <- check_reject(message),
          {:ok, message} <- check_ftl_removal(message),
          {:ok, message} <- check_replace(message) do