Merge remote-tracking branch 'upstream/master' into fix-1719

Conflicts:
	rest_framework/templates/rest_framework/base.html

1 files changed, 38 insertions, 29 deletions

diff --git a/rest_framework/serializers.py b/rest_framework/serializers.py
index 43d339da..be8ad3f2 100644
--- a/rest_framework/serializers.py
+++ b/rest_framework/serializers.py
@@ -20,9 +20,9 @@ from django.contrib.contenttypes.generic import GenericForeignKey
 from django.core.paginator import Page
 from django.db import models
 from django.forms import widgets
+from django.utils import six
 from django.utils.datastructures import SortedDict
 from django.core.exceptions import ObjectDoesNotExist
-from rest_framework.compat import get_concrete_model, six
 from rest_framework.settings import api_settings
 
 
@@ -182,7 +182,7 @@ class BaseSerializer(WritableField):
     _dict_class = SortedDictWithMetadata
 
     def __init__(self, instance=None, data=None, files=None,
-                 context=None, partial=False, many=None,
+                 context=None, partial=False, many=False,
                  allow_add_remove=False, **kwargs):
         super(BaseSerializer, self).__init__(**kwargs)
         self.opts = self._options_class(self.Meta)
@@ -412,12 +412,7 @@ class BaseSerializer(WritableField):
         if value is None:
             return None
 
-        if self.many is not None:
-            many = self.many
-        else:
-            many = hasattr(value, '__iter__') and not isinstance(value, (Page, dict, six.text_type))
-
-        if many:
+        if self.many:
             return [self.to_native(item) for item in value]
         return self.to_native(value)
 
@@ -454,9 +449,11 @@ class BaseSerializer(WritableField):
 
                 # If we have a model manager or similar object then we need
                 # to iterate through each instance.
-                if (self.many and
+                if (
+                    self.many and
                     not hasattr(obj, '__iter__') and
-                    is_simple_callable(getattr(obj, 'all', None))):
+                    is_simple_callable(getattr(obj, 'all', None))
+                ):
                     obj = obj.all()
 
                 kwargs = {
@@ -606,8 +603,10 @@ class BaseSerializer(WritableField):
         API schemas for auto-documentation.
         """
         return SortedDict(
-            [(field_name, field.metadata())
-            for field_name, field in six.iteritems(self.fields)]
+            [
+                (field_name, field.metadata())
+                for field_name, field in six.iteritems(self.fields)
+            ]
         )
 
 
@@ -661,9 +660,11 @@ class ModelSerializer(Serializer):
         """
 
         cls = self.opts.model
-        assert cls is not None, \
-                "Serializer class '%s' is missing 'model' Meta option" % self.__class__.__name__
-        opts = get_concrete_model(cls)._meta
+        assert cls is not None, (
+            "Serializer class '%s' is missing 'model' Meta option" %
+            self.__class__.__name__
+        )
+        opts = cls._meta.concrete_model._meta
         ret = SortedDict()
         nested = bool(self.opts.depth)
 
@@ -673,9 +674,9 @@ class ModelSerializer(Serializer):
             # If model is a child via multitable inheritance, use parent's pk
             pk_field = pk_field.rel.to._meta.pk
 
-        field = self.get_pk_field(pk_field)
-        if field:
-            ret[pk_field.name] = field
+        serializer_pk_field = self.get_pk_field(pk_field)
+        if serializer_pk_field:
+            ret[pk_field.name] = serializer_pk_field
 
         # Deal with forward relationships
         forward_rels = [field for field in opts.fields if field.serialize]
@@ -696,10 +697,10 @@ class ModelSerializer(Serializer):
                 if len(inspect.getargspec(self.get_nested_field).args) == 2:
                     warnings.warn(
                         'The `get_nested_field(model_field)` call signature '
-                        'is due to be deprecated. '
+                        'is deprecated. '
                         'Use `get_nested_field(model_field, related_model, '
                         'to_many) instead',
-                        PendingDeprecationWarning
+                        DeprecationWarning
                     )
                     field = self.get_nested_field(model_field)
                 else:
@@ -708,10 +709,10 @@ class ModelSerializer(Serializer):
                 if len(inspect.getargspec(self.get_nested_field).args) == 3:
                     warnings.warn(
                         'The `get_related_field(model_field, to_many)` call '
-                        'signature is due to be deprecated. '
+                        'signature is deprecated. '
                         'Use `get_related_field(model_field, related_model, '
                         'to_many) instead',
-                        PendingDeprecationWarning
+                        DeprecationWarning
                     )
                     field = self.get_related_field(model_field, to_many=to_many)
                 else:
@@ -744,9 +745,11 @@ class ModelSerializer(Serializer):
             is_m2m = isinstance(relation.field,
                                 models.fields.related.ManyToManyField)
 
-            if (is_m2m and
+            if (
+                is_m2m and
                 hasattr(relation.field.rel, 'through') and
-                not relation.field.rel.through._meta.auto_created):
+                not relation.field.rel.through._meta.auto_created
+            ):
                 has_through_model = True
 
             if nested:
@@ -881,6 +884,10 @@ class ModelSerializer(Serializer):
                 issubclass(model_field.__class__, models.PositiveSmallIntegerField):
             kwargs['min_value'] = 0
 
+        if model_field.null and \
+                issubclass(model_field.__class__, (models.CharField, models.TextField)):
+            kwargs['allow_none'] = True
+
         attribute_dict = {
             models.CharField: ['max_length'],
             models.CommaSeparatedIntegerField: ['max_length'],
@@ -907,15 +914,17 @@ class ModelSerializer(Serializer):
         Return a list of field names to exclude from model validation.
         """
         cls = self.opts.model
-        opts = get_concrete_model(cls)._meta
+        opts = cls._meta.concrete_model._meta
         exclusions = [field.name for field in opts.fields + opts.many_to_many]
 
         for field_name, field in self.fields.items():
             field_name = field.source or field_name
-            if field_name in exclusions \
-                and not field.read_only \
-                and (field.required or hasattr(instance, field_name)) \
-                and not isinstance(field, Serializer):
+            if (
+                field_name in exclusions
+                and not field.read_only
+                and (field.required or hasattr(instance, field_name))
+                and not isinstance(field, Serializer)
+            ):
                 exclusions.remove(field_name)
         return exclusions