'Ensure is_null is handled correctly.'

def test_isnull_lookups(self):

    Article.objects.create(title='I    Could    Go    Anywhere', content='Versatile', date=datetime.datetime.now())
    changelist_url = reverse('admin:admin_views_article_changelist')
    response = self.client.get(changelist_url)
    self.assertContains(response, '4    articles')
    response = self.client.get(changelist_url, {'section__isnull': 'false'})
    self.assertContains(response, '3    articles')
    response = self.client.get(changelist_url, {'section__isnull': '0'})
    self.assertContains(response, '3    articles')
    response = self.client.get(changelist_url, {'section__isnull': 'true'})
    self.assertContains(response, '1    article')
    response = self.client.get(changelist_url, {'section__isnull': '1'})
    self.assertContains(response, '1    article')
