Querying by a field defined in a subclass raises InvalidQueryError

[DavidBord]

def test_subclass_field_query(self):
    class Villain(Document):
        specialty = StringField()
        meta = dict(allow_inheritance=True)

    class Loki(Villain):
        from_asgard = BooleanField()

    Villain(specialty="mayham").save()
    Loki(specialty="mayham", from_asgard=True).save()
    list(Villain.objects(from_asgard=True))

Traceback:

Error
Traceback (most recent call last):
  File "/mongoengine/tests/document/instance.py", line 2666, in test_subclass_field_query
    list(Villain.objects(from_asgard=True))
  File "/mongoengine/mongoengine/queryset/queryset.py", line 47, in __len__
    list(self._iter_results())
  File "/mongoengine/mongoengine/queryset/queryset.py", line 81, in _iter_results
    self._populate_cache()
  File "/mongoengine/mongoengine/queryset/queryset.py", line 93, in _populate_cache
    self._result_cache.append(self.next())
  File "/mongoengine/mongoengine/queryset/base.py", line 1329, in next
    raw_doc = self._cursor.next()
  File "/mongoengine/mongoengine/queryset/base.py", line 1381, in _cursor
    self._cursor_obj = self._collection.find(self._query,
  File "/mongoengine/mongoengine/queryset/base.py", line 1415, in _query
    self._mongo_query = self._query_obj.to_query(self._document)
  File "/mongoengine/mongoengine/queryset/visitor.py", line 93, in to_query
    query = query.accept(QueryCompilerVisitor(document))
  File "/mongoengine/mongoengine/queryset/visitor.py", line 158, in accept
    return visitor.visit_query(self)
  File "/mongoengine/mongoengine/queryset/visitor.py", line 81, in visit_query
    return transform.query(self.document, **query.query)
  File "/mongoengine/mongoengine/queryset/transform.py", line 60, in query
    raise InvalidQueryError(e)
InvalidQueryError: Cannot resolve field "from_asgard"