Charfied from_native method returns default instead of None. Updated tests.

rest_framework/fields.py

@@ -469,8 +469,15 @@ class CharField(WritableField):
             self.validators.append(validators.MaxLengthValidator(max_length))
 
     def from_native(self, value):
-        if isinstance(value, six.string_types) or value is None:
+        if isinstance(value, six.string_types):
             return value
+
+        if value is None:
+            if self.default:
+                return self.default
+            else:
+                value
+
         return smart_text(value)
 
 

rest_framework/tests/models.py

@@ -105,6 +105,7 @@ class Album(RESTFrameworkModel):
     title = models.CharField(max_length=100, unique=True)
     ref = models.CharField(max_length=10, unique=True, null=True, blank=True)
 
+
 class Photo(RESTFrameworkModel):
     description = models.TextField()
     album = models.ForeignKey(Album)
@@ -112,7 +113,8 @@ class Photo(RESTFrameworkModel):
 
 # Model for issue #324
 class BlankFieldModel(RESTFrameworkModel):
-    title = models.CharField(max_length=100, blank=True, null=False)
+    title = models.CharField(max_length=100, blank=True, null=False,
+                             default="title")
 
 
 # Model for issue #380

rest_framework/tests/test_serializer.py

@@ -1238,6 +1238,7 @@ class BlankFieldTests(TestCase):
         self.assertEqual(serializer.is_valid(), True)
         serializer.save()
         self.assertTrue(serializer.object.pk is not None)
+        self.assertEqual(serializer.object.title, 'title')
 
     def test_create_not_blank_field(self):
         """