Fix breadcrumb rendering issue

docs/topics/release-notes.md

@@ -40,6 +40,12 @@ You can determine your currently installed version using `pip freeze`:
 
 ## 2.3.x series
 
+### 2.3.1
+
+**Date**: 7th May 2013
+
+* Bugfix: Fix breadcrumb rendering issue.
+
 ### 2.3.0
 
 **Date**: 7th May 2013

rest_framework/__init__.py

-__version__ = '2.3.0'
+__version__ = '2.3.1'
 
 VERSION = __version__  # synonym
 

rest_framework/utils/breadcrumbs.py

@@ -24,7 +24,8 @@ def get_breadcrumbs(url):
         else:
             # Check if this is a REST framework view,
             # and if so add it to the breadcrumbs
-            if issubclass(getattr(view, 'cls', None), APIView):
+            cls = getattr(view, 'cls', None)
+            if cls is not None and issubclass(cls, APIView):
                 # Don't list the same view twice in a row.
                 # Probably an optional trailing slash.
                 if not seen or seen[-1] != view: