Fixed #7512 -- Fixed an oversight when I first fixed ordering on nullable

            self.ref_alias(alias)

        # Must use left outer joins for nullable fields.

        must_promote = False

        for join in joins:

            self.promote_alias(join)

            must_promote = self.promote_alias(join, must_promote)

        # If we get to this point and the field is a relation to another model,

        # append the default ordering for that model.

"""

Regression tests for proper working of ForeignKey(null=True). Tests these bugs:

    * #7512: including a nullable foreign key reference in Meta ordering has un

xpected results

"""

from django.db import models

# The first two models represent a very simple null FK ordering case.

class Author(models.Model):

    name = models.CharField(max_length=150)

class Article(models.Model):

    title = models.CharField(max_length=150)

    author = models.ForeignKey(Author, null=True)

    def __unicode__(self):

        return u'Article titled: %s' % (self.title, )

    class Meta:

        ordering = ['author__name', ]

# These following 4 models represent a far more complex ordering case.

class SystemInfo(models.Model):

    system_name = models.CharField(max_length=32)

class Forum(models.Model):

    system_info = models.ForeignKey(SystemInfo)

    forum_name = models.CharField(max_length=32)

class Post(models.Model):

    forum = models.ForeignKey(Forum, null=True)

    title = models.CharField(max_length=32)

    def __unicode__(self):

        return self.title

class Comment(models.Model):

    post = models.ForeignKey(Post, null=True)

    comment_text = models.CharField(max_length=250)

    class Meta:

        ordering = ['post__forum__system_info__system_name', 'comment_text']

    def __unicode__(self):

        return self.comment_text

class Comment(models.Model):

    post = models.ForeignKey(Post, null=True)

    comment_text = models.CharField(max_length=250)

    class Meta:

        ordering = ['post__forum__system_info__system_name', 'comment_text']

    def __unicode__(self):

        return self.comment_text

__test__ = {'API_TESTS': """

# Regression test for #7512 -- ordering across nullable Foreign Keys shouldn't

# exclude results

>>> author_1 = Author.objects.create(name='Tom Jones')

>>> author_2 = Author.objects.create(name='Bob Smith')

>>> article_1 = Article.objects.create(title='No author on this article')

>>> article_2 = Article.objects.create(author=author_1, title='This article written by Tom Jones')

>>> article_3 = Article.objects.create(author=author_2, title='This article written by Bob Smith')

# We can't compare results directly (since different databases sort NULLs to

# different ends of the ordering), but we can check that all results are

# returned.

>>> len(list(Article.objects.all())) == 3

True

>>> 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')

>>> c1 = Comment.objects.create(post=p, comment_text='My first comment')

>>> c2 = 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')

>>> c3 = Comment.objects.create(comment_text='Another first comment')

>>> c4 = Comment.objects.create(post=p2, comment_text='Another second comment')

# We have to test this carefully. Some databases sort NULL values before

# everything else, some sort them afterwards. So we extract the ordered list

# and check the length. Before the fix, this list was too short (some values

# were omitted).

>>> len(list(Comment.objects.all())) == 4

True

"""

}