redirections and thus cannot use CURLOPT_FOLLOWLOCATION easily, we now
  introduce the new CURLINFO_REDIRECT_URL option that lets applications
  extract the URL libcurl would've redirected to if it had been told to. This
  then enables the application to continue to that URL as it thinks is
  suitable, without having to re-implement the magic of creating the new URL
  from the Location: header etc. Test 1029 verifies it.