Fix MRF reject for ChatMessage

lib/pleroma/web/api_spec/operations/chat_operation.ex

@@ -184,7 +184,8 @@ defmodule Pleroma.Web.ApiSpec.ChatOperation do
             "application/json",
             ChatMessage
           ),
-        400 => Operation.response("Bad Request", "application/json", ApiError)
+        400 => Operation.response("Bad Request", "application/json", ApiError),
+        422 => Operation.response("MRF Rejection", "application/json", ApiError)
       },
       security: [
         %{

lib/pleroma/web/api_spec/operations/status_operation.ex

@@ -55,7 +55,7 @@ defmodule Pleroma.Web.ApiSpec.StatusOperation do
             "application/json",
             %Schema{oneOf: [Status, ScheduledStatus]}
           ),
-        422 => Operation.response("Bad Request", "application/json", ApiError)
+        422 => Operation.response("Bad Request / MRF Rejection", "application/json", ApiError)
       }
     }
   end

lib/pleroma/web/common_api/common_api.ex

@@ -48,6 +48,9 @@ defmodule Pleroma.Web.CommonAPI do
               local: true
             )} do
       {:ok, activity}
+    else
+      {:common_pipeline, {:reject, _} = e} -> e
+      e -> e
     end
   end
 

lib/pleroma/web/pleroma_api/controllers/chat_controller.ex

@@ -90,6 +90,16 @@ defmodule Pleroma.Web.PleromaAPI.ChatController do
       conn
       |> put_view(MessageReferenceView)
       |> render("show.json", chat_message_reference: cm_ref)
+    else
+      {:reject, message} ->
+        conn
+        |> put_status(:unprocessable_entity)
+        |> json(%{error: message})
+
+      {:error, message} ->
+        conn
+        |> put_status(:bad_request)
+        |> json(%{error: message})
     end
   end