'Regression test for #7512
ordering across nullable Foreign Keys shouldn\'t exclude results'

def test_ordering_across_null_fk(self):

    author_1 = Author.objects.create(name='Tom    Jones')
    author_2 = Author.objects.create(name='Bob    Smith')
    Article.objects.create(title='No    author    on    this    article')
    Article.objects.create(author=author_1, title='This    article    written    by    Tom    Jones')
    Article.objects.create(author=author_2, title='This    article    written    by    Bob    Smith')
    self.assertEqual(len(list(Article.objects.all())), 3)
    s = SystemInfo.objects.create(system_name='System    Info')
    f = Forum.objects.create(system_info=s, forum_name='First    forum')
    p = Post.objects.create(forum=f, title='First    Post')
    Comment.objects.create(post=p, comment_text='My    first    comment')
    Comment.objects.create(comment_text='My    second    comment')
    s2 = SystemInfo.objects.create(system_name='More    System    Info')
    f2 = Forum.objects.create(system_info=s2, forum_name='Second    forum')
    p2 = Post.objects.create(forum=f2, title='Second    Post')
    Comment.objects.create(comment_text='Another    first    comment')
    Comment.objects.create(post=p2, comment_text='Another    second    comment')
    self.assertEqual(len(list(Comment.objects.all())), 4)
