The current Url Decorator does not allow the usage of URIs without a defined scheme. These are treated as relative instead.

eg.:

//static.example.com will be turned into /static.example.com by the decorator instead of leaving it as is.

Since PHP 5.4.7 parse_url correctly returns host when there is no scheme defined.

One use case is to allow CDN URIs which would use the same URI scheme as the main page the user is browsing.