Merge pull request #212 from jeflem/none_permissions_fix

Fix AttributeError if no permissions are available (webdav resources, for instance)

jupyterfs/fsmanager.py

@@ -281,7 +281,7 @@ def _base_model(self, path, info):
             try:
                 # Fall back on "u_w" check, even if we don't know if our user == owner...
                 model["writable"] = info.permissions.check("u_w")
-            except (errors.MissingInfoNamespace,):
+            except (errors.MissingInfoNamespace, AttributeError):
                 # use default if access namespace is missing
                 model["writable"] = self._default_writable
         except (OSError, PermissionDenied):