mhyeon.lee 3f8e69211f Fix OAuth2 ClientRegistration scope can be null
Allows scope of OAuth2 ClientRegistration to be null.

- The scope setting in the RFC document is defined as Optional.
https://tools.ietf.org/html/rfc6749#section-4.1.1

    > scope:  OPTIONAL.
    > The scope of the access request as described by Section 3.3.

- When the client omits the scope parameter,
validation is determined by the authorization server.
https://tools.ietf.org/html/rfc6749#section-3.3

    > If the client omits the scope parameter when requesting
   authorization, the authorization server MUST either process the
   request using a pre-defined default value or fail the request
   indicating an invalid scope.  The authorization server SHOULD
   document its scope requirements and default value (if defined).

Fixes gh-5494
2018-07-18 16:17:14 -04:00
..