Bug: Karma score/AJAX voting bug about drum HOT 5 CLOSED

@receiver(post_save, sender=Rating)
def karma(sender, **kwargs):
    """
    Each time a rating is saved, check its value and modify the
    profile karma for the related object's user accordingly.
    Since ratings are either +1/-1, if a rating is being edited,
    we can assume that the existing rating is in the other direction,
    so we multiply the karma modifier by 2.
    """
    rating = kwargs["instance"]
    value = int(rating.value)
    if not kwargs["created"]:
        value *= 2
    content_object = rating.content_object
    if rating.user != content_object.user:
        queryset = Profile.objects.filter(user=content_object.user)
        queryset.update(karma=models.F("karma") + value)