model inheritance with foreign key problem

[marcominutoli@…]

I have these three models:

class Address(models.Model):
   name = models.CharField(max_length=100)
   ## many other fields ##

   class Meta:
       ordering = ('name',)

   def __unicode__(self):
       return self.name


class Organization(models.Model):
   name = models.CharField(max_length=100)
   ## many other fields ##

   class Meta:
       ordering = ('name',)

   def __unicode__(self):
       return self.name


class OrganizationAddress(Address):
   organization = models.ForeignKey (
       Organization,
       related_name = "addresses",
   )

When i try to add/edit an organization and add one address i've got this error:

      " ValueError: Cannot assign None: "OrganizationAddress.address_ptr" does not allow null values. "

I've tried to understand the problem (because it happened since one day to another..) and i've found that the problem was born after the django commit of the changeset [9664]

This is the "incriminated code" of changeset:

	488	        if fk_attname == self._pk_field.attname: 
 	489	            exclude =  [self._pk_field.name] 
 	490	        else: 
 	491	            exclude = []

I have "organization_id" in the fk_attname e "address_ptr" in the self._pk_field.attname and so the primary_key wasn't insert in the exclude list.

Below a code portion to test the problem.

from django.forms.models import inlineformset_factory
from my_apps.models import Organization, Address, OrganizationAddress

Organization(name='test').save()
org = Organization.objects.get(name='test')

inline_formset = inlineformset_factory(Organization, OrganizationAddress, can_delete=False, extra=2)

data = {
   'addresses-TOTAL_FORMS': '2', # the number of forms rendered
   'addresses-INITIAL_FORMS': '0', # the number of forms with initial data
   'addresses-0-name': 'Test test',
}

formset = inline_formset(data, instance=org)

formset.is_valid()
formset.save()

Sorry for my english.
Marco M.

[Ramiro Morales]

(edited description, please please use the 'Preview' button when submitting a ticket)

[Karen Tracey]

OK, I attached a patch that slightly modifies the fix from r9664 to handle this case. I'm kind of guessing, though, since I'm not very familiar with the inheritance implementation nor the intricate details of inline formsets. Review from someone with more of a clue in this area would be appreciated.

[anonymous]

Tested with incriminated code and everything work as expected (=as before r9664).

[Simon Litchfield]

See somewhat related #10180.

[Malcolm Tredinnick]

Karen, this looks like a fix, at least, and we should probably commit it to make things more or less work. It feels a bit messy, having to special-case things like that and it might be a variation on the problem I want to fix that #9994 is the tip of the iceberg for. No amazing (internal) API comes to mind, though.

[Karen Tracey]

(In [9811]) Fixed #10075: Allowed saving of inline-edited models that use multi-table inheritance.

r9809 from trunk.