Change key type for RelatedField and ManyRelatedField choices

Fixes: #2416

choices() also did not work if queryset was a manager.
It would raise a "'*Manager' object is not iterable" that would
later get silenced by Django template system.

rest_framework/relations.py

@@ -111,10 +111,10 @@ class RelatedField(Field):
     def choices(self):
         return OrderedDict([
             (
-                six.text_type(self.to_representation(item)),
+                self.to_representation(item),
                 six.text_type(item)
             )
-            for item in self.get_queryset()
+            for item in self.get_queryset().all()
         ])
 
 

tests/test_relations.py

@@ -5,6 +5,7 @@ from django.core.exceptions import ImproperlyConfigured
 from django.utils.datastructures import MultiValueDict
 
 from rest_framework import serializers
+from rest_framework.compat import OrderedDict
 from rest_framework.fields import empty
 from rest_framework.test import APISimpleTestCase
 
@@ -58,6 +59,13 @@ class TestPrimaryKeyRelatedField(APISimpleTestCase):
         instance = field.to_internal_value(self.instance.pk)
         assert instance is self.instance
 
+    def test_choices(self):
+        self.assertEquals(
+            OrderedDict([(1, '<MockObject name=foo, pk=1>'),
+                         (2, '<MockObject name=bar, pk=2>'),
+                         (3, '<MockObject name=baz, pk=3>')]),
+            self.field.choices)
+
 
 class TestProxiedPrimaryKeyRelatedField(APISimpleTestCase):
     def setUp(self):
@@ -206,3 +214,17 @@ class TestManyRelatedField(APISimpleTestCase):
 
         mvd = MultiValueDict({'baz': ['bar1', 'bar2']})
         assert empty == self.field.get_value(mvd)
+
+    def test_choices(self):
+        queryset = MockQueryset([
+            MockObject(pk=1, name='foo'),
+            MockObject(pk=2, name='bar'),
+            MockObject(pk=3, name='baz')
+        ])
+        field = serializers.ManyRelatedField(
+            child_relation=serializers.PrimaryKeyRelatedField(queryset=queryset))
+        self.assertEquals(
+            OrderedDict([(1, '<MockObject name=foo, pk=1>'),
+                         (2, '<MockObject name=bar, pk=2>'),
+                         (3, '<MockObject name=baz, pk=3>')]),
+            field.choices)

tests/utils.py

@@ -53,6 +53,9 @@ class MockQueryset(object):
                 return item
         raise ObjectDoesNotExist()
 
+    def all(self):
+        return self.items
+
 
 class BadType(object):
     """