facebook/php-sdk — pull request #511 by donniekun (2011-12-21 07:26:25+00:00)
Title: http://fb.redirectstohere.com/logincheck?state=c4f3&code=b4b3&base_domain=fb.redirectstohere.com

Happens that FB may redirect back a new value 'base_domain=www.example.org' along with the usual 'state' and 'code'.

This can cause a OAuth 'Error validating verification code' error in getAccessTokenFromCode when the currentUrl does not tally with the original loginUrl that was sent.