From bca2ea35dff9cd673cee7600c1173adb21798560 Mon Sep 17 00:00:00 2001
From: Tom Christie <tom@tomchristie.com>
Date: Tue, 14 Jul 2015 13:21:08 +0100
Subject: [PATCH] Ensure that realtionship fields '.choices' returns an empty
 dict when accessed with a read-only field. Closes #2910.

---
 rest_framework/relations.py | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/rest_framework/relations.py b/rest_framework/relations.py
index c5cbfebcd..135b9614d 100644
--- a/rest_framework/relations.py
+++ b/rest_framework/relations.py
@@ -109,12 +109,18 @@ class RelatedField(Field):
 
     @property
     def choices(self):
+        queryset = self.get_queryset()
+        if queryset is None:
+            # Ensure that field.choices returns something sensible
+            # even when accessed with a read-only field.
+            return {}
+
         return OrderedDict([
             (
                 six.text_type(self.to_representation(item)),
                 six.text_type(item)
             )
-            for item in self.get_queryset()
+            for item in queryset
         ])