activitypub: upload: pass through an upload limit if one is provided

config/config.exs

@@ -84,6 +84,9 @@
   description: "A Pleroma instance, an alternative fediverse server",
   limit: 5000,
   upload_limit: 16_000_000,
+  avatar_upload_limit: 2_000_000,
+  background_upload_limit: 4_000_000,
+  banner_upload_limit: 4_000_000,
   registrations_open: true,
   federating: true,
   allow_relay: true,

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -575,9 +575,12 @@ def fetch_activities_bounded(recipients_to, recipients_cc, opts \\ %{}) do
     |> Enum.reverse()
   end
 
-  def upload(file) do
-    data = Upload.store(file, Application.get_env(:pleroma, :instance)[:dedupe_media])
-    Repo.insert(%Object{data: data})
+  def upload(file, size_limit \\ nil) do
+    with data <-
+           Upload.store(file, Application.get_env(:pleroma, :instance)[:dedupe_media], size_limit),
+         false <- is_nil(data) do
+      Repo.insert(%Object{data: data})
+    end
   end
 
   def user_data_from_user_object(data) do