_get_FIELD_display doesn't work with Field.get_choices using Iterators

[Areski Belaid]

Context:
This issue has been noted when fixing https://code.djangoproject.com/ticket/23112

Current behavior:
Using _get_FIELD_display on a Field.choices using Iterators, you will get the first tuple value.

Expected behavior:
Expected result is to get the human-readable name in from the iterator tuple.

Tests to reproduce the issue:

Edit tests/model_fields/tests.py add inside class ChoicesTests(test.TestCase) the following tests:

def test_iterator_choices_and_field_display(self):
    """
    Check that get_choices works with Iterators (#23112).
    """
    self.assertEqual(WhizIter(c=1).get_c_display(), 'val-1') # A nested value
    self.assertEqual(WhizIter(c=9).get_c_display(), 9) # Invalid value
    self.assertEqual(WhizIter(c=None).get_c_display(), None) # Blank value
    self.assertEqual(WhizIter(c='').get_c_display(), '') # Empty value

[Collin Anderson]

that's odd. it works for me.

In [2]: Address(country='CA').get_country_display()
Out[2]: u'Canada'

In [3]: Address(country='US').get_country_display()
Out[3]: u'United States'

In [4]: import django; django.get_version()
Out[4]: '1.8.dev20140805124457'

In [5]: Address._meta.get_field('country').choices
Out[5]: <itertools.tee at 0x2d978c0>

[Tim Graham]

I don't think there's an issue here. The Counter used for the choices in WhizIter generates values starting from two, not one so the provided test isn't correct. If you change the first line to self.assertEqual(WhizIter(c=2).get_c_display(), 'val-2') it passes.