The sort of software that’s used for research is the sort of software designed by engineers, not developers. With tight deadlines, corners get cut. This creates software that supports more shell injections, sql injections, and venous injections than useful functions. That’s bad, but all too common. This block that Koen found, on the other hand, is special.

if (substr($string,0,7) != "http://" ) {
    $string = "http://" . $string;
}

if (substr($string,0,7) == "http://" ) {
     $string = substr_replace($string,"",0,7);
}