Saving proxy model with raw=True gives UnboundLocalError 'record_exists'

[wardi]

When importing data I am running into this error:

Problem installing fixture '../tpm/contacts/fixtures/sampladata.json': Traceback (most recent call last):
  File "/usr/local/lib/python2.5/site-packages/django/core/management/commands/loaddata.py", line 153, in handle
    obj.save()
  File "/usr/local/lib/python2.5/site-packages/django/core/serializers/base.py", line 163, in save
    models.Model.save_base(self.object, raw=True)
  File "/usr/local/lib/python2.5/site-packages/django/db/models/base.py", line 495, in save_base
    created=(not record_exists), raw=raw)
UnboundLocalError: local variable 'record_exists' referenced before assignment

[wardi]

patch to define record_exists in all cases

[Karen Tracey]

It would help if you would provide sample data to recreate the error. If all fixture loading was broken, the test suite would be having serious problems, and it is not. So what is special about you data that is triggering this problem?

[dc]

I can reproduce this error with this model:

from django.contrib.auth.models import User
class UserProxy(User):
    class Meta:
        proxy = True

and with any fixture, for e.g.

{
	"model": "myapp.userproxy",
	"pk": 1,
	"fields": {
		"username": "username"
	}
}

It also can be repoduced without fixtures:

>>> from myapp.models import UserProxy
>>> UserProxy(username='username').save_base(raw=True)
Traceback (most recent call last):
...
UnboundLocalError: local variable 'record_exists' referenced before assignment

[Karen Tracey]

OK, so the problem is a combination of using raw=True (as fixture loading (always?) does) and proxy models. It looks to me like the save_base routine is coded to never expect to be called with both raw=True and meta.proxy=True. The attached patch fixes the visible error (avoids an exception) but the resulting behavior of the function does not appear to be correct. It sends a pre-save signal, then skips out on the saving of parent class(es) because raw is True, then skips out on the remainder of the try an update, try an insert logic because meta.proxy is True. The only thing left not under the if not meta.proxy is the sending of the post save signal. So that patch makes it possible to call the routine, and the pre and post save signals will be sent, but nothing will be saved. There seems to be a deeper problem than a local variable used before being set here.

Setting 1.1 milestone because someone with a clue about proxy models and serialization should probably look at this before 1.1.

[Russell Keith-Magee]

(In [10955]) Fixed #11194 -- Corrected loading of Proxy models from fixtures (and, by extension, save_base(raw=True) for Proxy models).

[Jacob]

Milestone 1.1 deleted