--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/parts/django/tests/regressiontests/null_fk_ordering/tests.py	Sat Jan 08 11:20:57 2011 +0530
@@ -0,0 +1,39 @@
+from django.test import TestCase
+
+from regressiontests.null_fk_ordering.models import *
+
+class NullFkOrderingTests(TestCase):
+
+    def test_ordering_across_null_fk(self):
+        """
+        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.
+        self.assertTrue(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')
+        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).
+        self.assertTrue(len(list(Comment.objects.all())) == 4)