problem w/ reverse relationships & recursion in ModelResources

[phobologic]

Hi, I'm running into an issue where if I include a reverse relationship in a ModelResource it recurses repeatedly back and forth between the original object & the related object. Here's an example:

# models.py
from django.db import models

class Host(models.Model):
    name = models.CharField(max_length=16, unique=True)

    def __unicode__(self):
        return unicode(self.name)

    @property
    def extra(self):
        related_name = self.__class__.__name__.lower() + 'extra'
        return getattr(self, related_name)


class HostExtra(models.Model):
    host = models.OneToOneField(Host)
    ip = models.IPAddressField()

    def __unicode__(self):
        return unicode("%s: %s" % (self.host.name, self.ip))

# api.py
from djangorestframework.resources import ModelResource
from djangorestframework.reverse import reverse
from apps.recursion.models import Host

class HostResource(ModelResource):
    model = Host
    include = ('extra',)

    def url(self, instance):
        return reverse('host_resource', kwargs={'id': instance.id},
                request=self.request)

# creating the objects
>>> x = Host(name='foo')
>>> x.save()
>>> e = HostExtra(host=x, ip='192.168.2.1')
>>> e.save()

Here's an example of the output that I get when I make the query:

[{"name": "foo", "extra": {"ip": "192.168.2.1", "host": {"name": "foo", "extra": {"ip": "192.168.2.1", "host": {"name": "foo", "extra": {"ip": "192.168.2.1", "host": {"name": "foo", "extra": {"ip": "192.168.2.1", "host": {"name": "foo", "extra": {"ip": "192.168.2.1", "host": {"name": "foo", "extra": {"ip": "192.168.2.1", "host": {"name": "foo", "extra"
...

I took a look at the code, and this bit (in serializer.py, line 185) seems to be intended to stop this, but it fails:

        if any([obj is elem for elem in self.stack]):
            return self.serialize_recursion(obj)

However, if I replace that if statement with the following it works fine:

        if obj in self.stack:
            return self.serialize_recursion(obj)

[tomchristie]

Seems valid. Care to submit a pull req?
I'm freezing updates to 0.4 pending the incoming 2.0 release, but clear bugs like this I think should still make it in.

[phobologic]

Done, thanks!