- return subclasses[status](status, message)
-
- def __init__(self, status, message=None):
+ return subclasses[status]
+
+ def __new__(cls, *args, **kwargs):
+ """Return a correct subclass of NotmuchError if needed
+
+ We return a NotmuchError instance if status is None (or 0) and a
+ subclass that inherits from NotmuchError depending on the
+ 'status' parameter otherwise."""
+ # get 'status'. Passed in as arg or kwarg?
+ status = args[0] if len(args) else kwargs.get('status', None)
+ # no 'status' or cls is subclass already, return 'cls' instance
+ if not status or cls != NotmuchError:
+ return super(NotmuchError, cls).__new__(cls)
+ subclass = cls.get_exc_subclass(status) # which class to use?
+ return subclass.__new__(subclass, *args, **kwargs)
+
+ def __init__(self, status=None, message=None):