Summary: We sometimes call PhabricatorEnv::getProductionURI($file->getBestURI()) or similar, but this may currently cause us to construct a URI like this: http://domain.com/http://cdn-domain.com/file/data/xxx/yyy/name.jpg Instead, if the provided URI has a domain already, leave it unmodified. Test Plan: Attached a file to a task; got an email with a valid URI instead of an invalid URI. Reviewers: btrahan Reviewed By: btrahan CC: Makinde, aran, epriestley Differential Revision: https://secure.phabricator.com/D1622