Ticket #12420: t12420_1.diff

django/forms/models.py

@@ -50 +50 @@
             continue
         # OneToOneField doesn't allow assignment of None. Guard against that
         # instead of allowing it and throwing an error.
-        if isinstance(f, models.OneToOneField) and cleaned_data[f.name] is None:
+        if isinstance(f, models.OneToOneField) and not f.null and cleaned_data[f.name] is None:
             continue
         # Defer saving file-type fields until after the other fields, so a
         # callable upload_to can use the values from other fields.

tests/regressiontests/model_forms_regress/models.py

@@ -37 +37 @@
 
 class CustomFF(models.Model):
     f = CustomFileField(upload_to='unused', blank=True)
+
+class Author(models.Model):
+    publication = models.OneToOneField(Publication, null=True, blank=True)
+    full_name = models.CharField(max_length=255)

tests/regressiontests/model_forms_regress/tests.py

@@ -6 +6 @@
 from django.conf import settings
 from django.test import TestCase
 
-from models import Person, Triple, FilePathModel, Article, Publication, CustomFF
+from models import Person, Triple, FilePathModel, Article, Publication, CustomFF, Author
 
 class ModelMultipleChoiceFieldTests(TestCase):
 
@@ -134 +134 @@
             date_published=date(1991, 8, 22))
         f = Form()
         self.assertEqual(len(f.fields["publications"].choices), 1)
+
+class OneToOneFieldTests(TestCase):
+    def test_non_assignment(self):
+        class AuthorForm(forms.ModelForm):
+            class Meta:
+                model = Author
+                fields = ['publication', 'full_name']
+
+        publication = Publication.objects.create(title="Pravda",
+            date_published=date(1991, 8, 22))
+        author = Author.objects.create(publication=publication, full_name='John Doe')
+        form = AuthorForm({'publication':u'', 'full_name':'John Doe'}, instance=author)
+        if form.is_valid():
+            self.assertEqual(form.cleaned_data['publication'], None)
+            author = form.save()
+            #author object returned from form still retains original publication object
+            #that's why we need to retreive it from database again
+            new_author = Author.objects.get(pk=author.pk)
+            self.assertEqual(new_author.publication, None)