From 296ebc5c274f2dfff46a4ac916851e8c73b8a21e Mon Sep 17 00:00:00 2001
From: 5505005 <964309172@qq.com>
Date: Tue, 26 Mar 2019 22:06:01 +0800
Subject: [PATCH] When i using the source function of serializers there was a
 problem, the source of a foreign key field will give me an error named
 incorrectly and not match any attribute, the foreign key is correct, but I
 just haven't add data, it is clearly wrong, so I modified the code, let it
 out key correctly and without adding data return None

---
 rest_framework/fields.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/rest_framework/fields.py b/rest_framework/fields.py
index c8f65db0e..adec05eec 100644
--- a/rest_framework/fields.py
+++ b/rest_framework/fields.py
@@ -101,6 +101,8 @@ def get_attribute(instance, attrs):
                 instance = getattr(instance, attr)
         except ObjectDoesNotExist:
             return None
+        if instance == None:
+            return None
         if is_simple_callable(instance):
             try:
                 instance = instance()