defer('related__subfield') and select_related() on proxy model raises error

[lovasb]

Given model (in the defer test directory):

class Secondary(models.Model):
    first = models.CharField(max_length=50)
    second = models.CharField(max_length=50)


@python_2_unicode_compatible
class Primary(models.Model):
    name = models.CharField(max_length=50)
    value = models.CharField(max_length=50)
    related = models.ForeignKey(Secondary)

    def __str__(self):
        return self.name
        
class PrimaryProxy(Primary):
    class Meta:
        proxy = True

Select only() on related models: PrimaryProxy.objects.all().select_related().only('related__first')
Raises KeyError:

E
======================================================================
ERROR: test_defer_proxy_related_field (defer.tests.DeferTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/lovasb/WORK/Personal/django/tests/defer/tests.py", line 176, in test_defer_proxy_related_field
    self.assertEqual(len(children), 1)
  File "/home/lovasb/WORK/Personal/django/django/db/models/query.py", line 122, in __len__
    self._fetch_all()
  File "/home/lovasb/WORK/Personal/django/django/db/models/query.py", line 963, in _fetch_all
    self._result_cache = list(self.iterator())
  File "/home/lovasb/WORK/Personal/django/django/db/models/query.py", line 222, in iterator
    only_load = self.query.get_loaded_field_names()
  File "/home/lovasb/WORK/Personal/django/django/db/models/sql/query.py", line 1819, in get_loaded_field_names
    self.deferred_to_data(collection, self.get_loaded_field_names_cb)
  File "/home/lovasb/WORK/Personal/django/django/db/models/sql/query.py", line 602, in deferred_to_data
    must_include[old_model].add(source)
KeyError: <class 'defer.models.PrimaryProxy'>

[lovasb]

Defer test models.py

[lovasb]

Defer tests.py

[lovasb]

Patch.py

[Baptiste Mispelon]

Hi,

Could you submit a pull request for this, or at least consolidate all the patches into one? It would make reviewing the ticket easier.

Thanks.

[Baptiste Mispelon]

Looks like there's one already: ​https://github.com/django/django/pull/2279

[lovasb]

Replying to bmispelon:

Hi,

Could you submit a pull request for this, or at least consolidate all the patches into one? It would make reviewing the ticket easier.

Thanks.

Hi,

Here is my pull request: ​https://github.com/django/django/pull/2279/files

Bence

[lovasb]

Replying to bmispelon:

Looks like there's one already: ​https://github.com/django/django/pull/2279

Yeah, that's mine! :)

[Tim Graham <timograham@…>]

In 9385aa3198e7ab460990dd8f82e466fd243557a0:

Fixed #22050 -- Fixed defer fields on proxy related models.