From 905a5579dfaa717ad4210ddd285267bb9bbb9a43 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=B4mulo=20Oliveira?= <romulo.ac.oliveira@gmail.com>
Date: Fri, 1 Dec 2017 06:54:25 -0200
Subject: [PATCH] Non-required fields with 'allow_null=True' should not imply a
 default value (#5639)

Ref #5518.
---
 rest_framework/fields.py | 4 ++--
 tests/test_serializer.py | 8 ++++++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/rest_framework/fields.py b/rest_framework/fields.py
index 55c2fe48e9..a710df7b48 100644
--- a/rest_framework/fields.py
+++ b/rest_framework/fields.py
@@ -442,10 +442,10 @@ def get_attribute(self, instance):
         except (KeyError, AttributeError) as exc:
             if self.default is not empty:
                 return self.get_default()
-            if self.allow_null:
-                return None
             if not self.required:
                 raise SkipField()
+            if self.allow_null:
+                return None
             msg = (
                 'Got {exc_type} when attempting to get a value for field '
                 '`{field}` on serializer `{serializer}`.\nThe serializer '
diff --git a/tests/test_serializer.py b/tests/test_serializer.py
index 23c6ec2c10..0c30deb916 100644
--- a/tests/test_serializer.py
+++ b/tests/test_serializer.py
@@ -372,6 +372,14 @@ def create(self, validated_data):
         serializer.save()
         assert serializer.data == {'included': 'abc'}
 
+    def test_not_required_output_for_allow_null_field(self):
+        class ExampleSerializer(serializers.Serializer):
+            omitted = serializers.CharField(required=False, allow_null=True)
+            included = serializers.CharField()
+
+        serializer = ExampleSerializer({'included': 'abc'})
+        assert 'omitted' not in serializer.data
+
 
 class TestDefaultOutput:
     def setup(self):