Merge pull request 'Fix Pleroma’s unlisted posts' (#885) from Oneric/akkoma:pleroma_unlisted into develop

Reviewed-on: https://akkoma.dev/AkkomaGang/akkoma/pulls/885

lib/pleroma/web/activity_pub/transmogrifier.ex

@@ -118,7 +118,7 @@ defp normalise_addressing_public_list(%{} = map, [field | fields]) do
 
         Map.put(map, field, new_fval)
       else
-        map
+        Map.put(map, field, [])
       end
 
     normalise_addressing_public_list(map, fields)
@@ -208,6 +208,19 @@ def fix_in_reply_to(%{"inReplyTo" => in_reply_to} = object, options)
 
   def fix_in_reply_to(object, _options), do: object
 
+  # Pleroma sends unlisted posts without addressing public scope in the enclosing activity
+  # but we only use the ativity for access perm cheks, see:
+  # https://git.pleroma.social/pleroma/pleroma/-/issues/3323
+  defp fix_create_visibility(%{"type" => "Create", "object" => %{} = object} = activity) do
+    activity
+    |> Map.put("to", object["to"])
+    |> Map.put("cc", object["cc"])
+    |> Map.put("bto", object["bto"])
+    |> Map.put("bcc", object["bcc"])
+  end
+
+  defp fix_create_visibility(activity), do: activity
+
   def fix_quote_url(object, options \\ [])
 
   def fix_quote_url(%{"quoteUri" => quote_url} = object, options)
@@ -513,6 +526,7 @@ defp handle_incoming_normalised(
        )
        when objtype in ~w{Question Answer Audio Video Event Article Note Page} do
     fetch_options = Keyword.put(options, :depth, (options[:depth] || 0) + 1)
+    data = fix_create_visibility(data)
 
     object =
       data["object"]

test/pleroma/web/activity_pub/transmogrifier/note_handling_test.exs

@@ -17,6 +17,8 @@ defmodule Pleroma.Web.ActivityPub.Transmogrifier.NoteHandlingTest do
   import Mock
   import Pleroma.Factory
 
+  require Pleroma.Constants
+
   setup_all do
     Tesla.Mock.mock_global(fn env -> apply(HttpRequestMock, :request, [env]) end)
     :ok
@@ -276,6 +278,32 @@ test "it ensures that address fields become lists" do
       refute is_nil(data["cc"])
     end
 
+    test "it fixes Pleroma unlisted" do
+      # https://git.pleroma.social/pleroma/pleroma/-/issues/3323
+      user1 = insert(:user)
+      user2 = insert(:user)
+
+      data =
+        File.read!("test/fixtures/mastodon-post-activity.json")
+        |> Jason.decode!()
+        |> Map.put("actor", user1.ap_id)
+        |> Map.put("cc", [])
+        |> Map.put("to", [user2.ap_id, user1.follower_address])
+
+      object =
+        data["object"]
+        |> Map.put("attributedTo", user1.ap_id)
+        |> Map.put("cc", [Pleroma.Constants.as_public()])
+        |> Map.put("to", [user2.ap_id, user1.follower_address])
+        |> Map.put("id", user1.ap_id <> "/activities/12345678")
+
+      data = Map.put(data, "object", object)
+
+      {:ok, %Activity{} = activity} = Transmogrifier.handle_incoming(data)
+
+      assert "unlisted" == Pleroma.Web.ActivityPub.Visibility.get_visibility(activity)
+    end
+
     test "it strips internal likes" do
       data =
         File.read!("test/fixtures/mastodon-post-activity.json")