Fix logging of unknown options

flask_cors/core.py

@@ -40,7 +40,6 @@
                   'CORS_MAX_AGE', 'CORS_SEND_WILDCARD',
                   'CORS_AUTOMATIC_OPTIONS', 'CORS_VARY_HEADER',
                   'CORS_RESOURCES', 'CORS_INTERCEPT_EXCEPTIONS']
-
 # Attribute added to request object by decorator to indicate that CORS
 # was evaluated, in case the decorator and extension are both applied
 # to a view.
@@ -52,10 +51,12 @@
 DEFAULT_OPTIONS = dict(origins='*',
                        methods=ALL_METHODS,
                        allow_headers='*',
-                       automatic_options=True,
+                       expose_headers=None,
+                       supports_credentials=False,
+                       max_age=None,
                        send_wildcard=False,
+                       automatic_options=True,
                        vary_header=True,
-                       supports_credentials=False,
                        resources=r'/*',
                        intercept_exceptions=True)
 
@@ -287,7 +288,9 @@ def flexible_str(obj):
     to ensure generated responses are consistent when iterables such as Set
     are used.
     """
-    if(not isinstance(obj, string_types)
+    if obj is None:
+        return None
+    elif(not isinstance(obj, string_types)
             and isinstance(obj, collections.Iterable)):
         return ', '.join(str(item) for item in sorted(obj))
     else:

flask_cors/extension.py

@@ -121,14 +121,6 @@ class CORS(object):
 
         Default : True
     :type vary_header: bool
-
-    :param automatic_options:
-        Only applies to the `cross_origin` decorator. If True, Flask-CORS will
-        override Flask's default OPTIONS handling to return CORS headers for
-        OPTIONS requests.
-
-        Default : True
-    :type automatic_options: bool
     """
 
     def __init__(self, app=None, **kwargs):