Admin ChangeList bypasses model's custom manager

[Ionut Ciocirlan <ionut.ciocirlan@…>]

When using a custom manager for Model.objects that overrides Manager.get_query_set(), the admin ChangeList disregards it. E.g.:

from django.db import models

class MyManager(models.Manager):
    def get_query_set(self):
        return super(MyManager, self).get_query_set().filter(mybool=False)

class MyModel(models.Model):
    mybool = models.BooleanField()
    objects = MyManager()

To reproduce it, add a MyModel object with mybool set to true. The item will appear in the list. While this might be (quite debatably) a good approach, it is inconsistent as trying to edit the object in admin will lead to a 404: object with primary key u'1' does not exist.

[Ionut Ciocirlan <ionut.ciocirlan@…>]

Created the patch above, which fixes the behaviour.

I checked patch needs improvement, as I didn't read the code to see what model._meta.admin.manager actually does and why it was used here.

However, this does work as expected, regardless of the model.objects having been overwritten, and list filters and pagination are preserved.

[Brian Rosner]

model._meta.admin.manager is an undocumented feature of the admin in trunk that is meant for exactly what you are trying to do. Set it up in your model's Admin inner-class. This has been fixed in newforms-admin therefore marking as invalid.

[Ionut Ciocirlan <ionut.ciocirlan@…>]

If so, then the bug is not in change_list, but in change_stage as it uses the model's manager.

And while I agree that strictly speaking the bug is invalid, and I should add a new bug, having been fixed in a branch is a poor explanation for it. The bug was submitted against trunk. Chances are that the "new" bug exists in newforms-admin as well.

[Brian Rosner]

There is no bug here. The real problem was that the manager option was never documented. Had it been, this would have never been a problem. The current admin application in trunk is no longer supported and will be replaced by newforms-admin. Even if this were a bug then it would have been triaged towards newforms-admin. This problem does not exist because you can define the queryset to use for the ChangeList making this obsolete.