Do not hide request auth attribute errors

Author: Ryan P Kilby

rest_framework/request.py

@@ -380,6 +380,11 @@ def __getattribute__(self, attr):
         try:
             return super(Request, self).__getattribute__(attr)
         except AttributeError:
+            # Do not proxy attribute access for `user` and `auth`, as this
+            # potentially hides AttributeError's raised in `_authenticate`.
+            if attr in ['user', 'auth']:
+                raise
+
             info = sys.exc_info()
             try:
                 return getattr(self._request, attr)