I have a hybrid mobile app that logs into a customer community. The Community has a custom login page the provides the sso links to 3 Auth Providers i've configured (FB, Google, LinkedIn). If the user clicks the link and successfully logs in to the social auth provider, my Reg handler is called; if the reg handler authenticates the user, everything works.
Where I have questions are where the process goes wrong: if the login process fails, the system calls the Custom Error URL defined for the auth provider; in this case, it's a publicly accessible page within the community site that explains the login error and provides a link back to the login page - we don't want to show the OOB Salesforce error page.
It works, except as soon as the custom error page displays, it is replaced with a dialog, "Can't connect to Salesforce: the URL can't be shown". Clicking Retry (only option) returns you to the login page. I believe the auth manager sees that we've strayed outside the auth flow and interceeds; it works but it is ugly. I'd like to just display the auth page. Is there a way I can prevent this? Some way to whitelist the error page with the auth manager?