Unauthorized() overrides www_authenticate=None

[billyrrr]

Unauthorized in werkzeug==0.15.2

class Unauthorized(HTTPException):
    """*401* ``Unauthorized``

    Raise if the user is not authorized to access a resource.

    The ``www_authenticate`` argument should be used to set the
    ``WWW-Authenticate`` header. This is used for HTTP basic auth and
    other schemes. Use :class:`~werkzeug.datastructures.WWWAuthenticate`
    to create correctly formatted values. Strictly speaking a 401
    response is invalid if it doesn't provide at least one value for
    this header, although real clients typically don't care.

    :param description: Override the default message used for the body
        of the response.
    :param www-authenticate: A single value, or list of values, for the
        WWW-Authenticate header.

    .. versionchanged:: 0.15.1
        ``description`` was moved back as the first argument, restoring
         its previous position.

    .. versionchanged:: 0.15.0
        ``www_authenticate`` was added as the first argument, ahead of
        ``description``.
    """

    code = 401
    description = (
        "The server could not verify that you are authorized to access"
        " the URL requested. You either supplied the wrong credentials"
        " (e.g. a bad password), or your browser doesn't understand"
        " how to supply the credentials required."
    )

    def __init__(self, description=None, www_authenticate=None):
        HTTPException.__init__(self, description)
        if not isinstance(www_authenticate, (tuple, list)):
            www_authenticate = (www_authenticate,)
        self.www_authenticate = www_authenticate

    def get_headers(self, environ=None):
        headers = HTTPException.get_headers(self, environ)
        if self.www_authenticate:
            headers.append(
                ("WWW-Authenticate", ", ".join([str(x) for x in self.www_authenticate]))
            )
        return headers

When www_authenticate=None, self.www_authenticate will still be overridden and initialized.

Unauthorized in werkzeug==0.14.1

class Unauthorized(HTTPException):

    """*401* `Unauthorized`
    Raise if the user is not authorized.  Also used if you want to use HTTP
    basic auth.
    """
    code = 401
    description = (
        'The server could not verify that you are authorized to access '
        'the URL requested.  You either supplied the wrong credentials (e.g. '
        'a bad password), or your browser doesn\'t understand how to supply '
        'the credentials required.'
    )