Fixed #9462 -- Set the instance in an inline formset correctly so that None does…

Fixed #9462 -- Set the instance in an inline formset correctly so that None does not get passed through to the queryset. Thanks tobias and copelco for the ticket.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@9293 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/forms/models.py

@@ -446,7 +446,10 @@ class BaseInlineFormSet(BaseModelFormSet):
     def __init__(self, data=None, files=None, instance=None,
                  save_as_new=False, prefix=None):
         from django.db.models.fields.related import RelatedObject
-        self.instance = instance
+        if instance is None:
+            self.instance = self.model()
+        else:
+            self.instance = instance
         self.save_as_new = save_as_new
         # is there a better way to get the object descriptor?
         self.rel_name = RelatedObject(self.fk.rel.to, self.model, self.fk).get_accessor_name()

tests/modeltests/model_formsets/models.py

@@ -107,6 +107,17 @@ class Membership(models.Model):
     date_joined = models.DateTimeField(default=datetime.datetime.now)
     karma = models.IntegerField()
 
+# models for testing a null=True fk to a parent
+class Team(models.Model):
+    name = models.CharField(max_length=100)
+
+class Player(models.Model):
+    team = models.ForeignKey(Team, null=True)
+    name = models.CharField(max_length=100)
+    
+    def __unicode__(self):
+        return self.name
+
 __test__ = {'API_TESTS': """
 
 >>> from datetime import date
@@ -701,4 +712,19 @@ False
 >>> formset.is_valid()
 True
 
+# inlineformset_factory tests with fk having null=True. see #9462.
+# create some data that will exbit the issue
+>>> team = Team.objects.create(name=u"Red Vipers")
+>>> Player(name="Timmy").save()
+>>> Player(name="Bobby", team=team).save()
+
+>>> PlayerInlineFormSet = inlineformset_factory(Team, Player)
+>>> formset = PlayerInlineFormSet()
+>>> formset.get_queryset()
+[]
+
+>>> formset = PlayerInlineFormSet(instance=team)
+>>> formset.get_queryset()
+[<Player: Bobby>]
+
 """}