An openid cancel operation is not handled and default (ugly) handler is used

[Natalia Bidart]

After contacting an openid provider such as SSO, if the user decides to "go back" to the relying party that redirected her to SSO, the provider will redirect the user to the relying party's complete url with proper query params indicating the success or failure of the auth operation, plus a reason.

For example, if U1 redirects a user to SSO to do login and the user cancels the operation, the return url is:

https://one.ubuntu.com/auth/complete/?next=%2Fservices%2Fsubscribe-base%2F&janrain_nonce=2013-01-17T19%3A46%3A08ZDxh0Wp&openid.mode=cancel&openid.ns=http%3A%2F%2Fspecs.openid.net%2Fauth%2F2.0

(note the "openid.mode=cancel" in the url).

Right now, all the affected (in this bug) services show an unthemed, unformatted, ugly, page reading:

OpenID failed

Authentication cancelled