From 5c680c36e435ffa29ba6ed5f439d22ea4e849c67 Mon Sep 17 00:00:00 2001
From: Mark Aaron Shirley <maspwr@gmail.com>
Date: Wed, 19 Dec 2012 09:26:40 -0800
Subject: [PATCH] Check if RelatedField is required.

---
 rest_framework/fields.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/rest_framework/fields.py b/rest_framework/fields.py
index 2060e3e70..b0dfdce8c 100644
--- a/rest_framework/fields.py
+++ b/rest_framework/fields.py
@@ -351,6 +351,11 @@ class RelatedField(WritableField):
         if self.read_only:
             return
 
+        if field_name not in data and self.required:
+            raise ValidationError(self.error_messages['required'])
+        elif field_name not in data:
+            return
+
         value = data.get(field_name)
 
         if value in (None, '') and not self.null: