Fixed #12819. Fixed a bug with caching values of nullable 1to1 fields. Thanks,…

Fixed #12819. Fixed a bug with caching values of nullable 1to1 fields. Thanks, s.angel@twidi.com for the initial patch, and Alex Gaynor for the tests.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12543 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/db/models/query.py

@@ -1203,7 +1203,7 @@ def get_cached_row(klass, row, index_start, max_depth=0, cur_depth=0,
                 # If the base object exists, populate the
                 # descriptor cache
                 setattr(obj, f.get_cache_name(), rel_obj)
-            if f.unique:
+            if f.unique and rel_obj is not None:
                 # If the field is unique, populate the
                 # reverse descriptor cache on the related object
                 setattr(rel_obj, f.related.get_cache_name(), obj)

tests/regressiontests/select_related_onetoone/models.py

@@ -44,3 +44,12 @@ class StatDetails(models.Model):
 
 class AdvancedUserStat(UserStat):
     pass
+
+
+class Image(models.Model):
+    name = models.CharField(max_length=100)
+
+
+class Product(models.Model):
+    name = models.CharField(max_length=100)
+    image = models.OneToOneField(Image, null=True)

tests/regressiontests/select_related_onetoone/tests.py

@@ -2,7 +2,8 @@ from django import db
 from django.conf import settings
 from django.test import TestCase
 
-from models import User, UserProfile, UserStat, UserStatResult, StatDetails, AdvancedUserStat
+from models import (User, UserProfile, UserStat, UserStatResult, StatDetails, 
+    AdvancedUserStat, Image, Product)
 
 class ReverseSelectRelatedTestCase(TestCase):
     def setUp(self):
@@ -81,3 +82,10 @@ class ReverseSelectRelatedTestCase(TestCase):
         stat = UserStat.objects.select_related('advanceduserstat').get(posts=200)
         self.assertEqual(stat.advanceduserstat.posts, 200)
         self.assertQueries(1)
+    
+    def test_nullable_relation(self):
+        im = Image.objects.create(name="imag1")
+        p1 = Product.objects.create(name="Django Plushie", image=im)
+        p2 = Product.objects.create(name="Talking Django Plushie")
+        
+        self.assertEqual(len(Product.objects.select_related("image")), 2)