Fixed #5570: generic foreign keys no longer do multiple lookups on the content...

        # content-type/object-id fields.

        if self.name in kwargs:

            value = kwargs.pop(self.name)

            kwargs[self.ct_field] = self.get_content_type(value)

            kwargs[self.ct_field] = self.get_content_type(obj=value)

            kwargs[self.fk_field] = value._get_pk_val()

    def get_content_type(self, obj):

    def get_content_type(self, obj=None, id=None):

        # Convenience function using get_model avoids a circular import when using this model

        ContentType = get_model("contenttypes", "contenttype")

        if obj:

            return ContentType.objects.get_for_model(obj)

        elif id:

            return ContentType.objects.get_for_id(id)

        else:

            # This should never happen. I love comments like this, don't you?

            raise Exception("Impossible arguments to GFK.get_content_type!")

    def __get__(self, instance, instance_type=None):

        if instance is None:

            return getattr(instance, self.cache_attr)

        except AttributeError:

            rel_obj = None

            ct = getattr(instance, self.ct_field)

            if ct:

            # Make sure to use ContentType.objects.get_for_id() to ensure that

            # lookups are cached (see ticket #5570). This takes more code than

            # the naive ``getattr(instance, self.ct_field)``, but has better 

            # performance when dealing with GFKs in loops and such.

            f = self.model._meta.get_field(self.ct_field)

            ct_id = getattr(instance, f.get_attname(), None)

            if ct_id:

                ct = self.get_content_type(id=ct_id)

                try:

                    rel_obj = ct.get_object_for_this_type(pk=getattr(instance, self.fk_field))

                except ObjectDoesNotExist:

        ct = None

        fk = None

        if value is not None:

            ct = self.get_content_type(value)

            ct = self.get_content_type(obj=value)

            fk = value._get_pk_val()

        setattr(instance, self.ct_field, ct)