/**
* Test if folder is subfolder of its parent folder.
*
* @param string $subfolder absolute path to folder which we need test
* @param string $folder absolute path to tested folder parent folder
* @return mixed true/false/null - is subfolder/is not subfolder/unable test
*/
public static function isSubFolder($subfolder, $folder)
{
$subfolder = JPath::clean($subfolder);
$folder = JPath::clean($folder);
if (!JoomDOCFileSystem::exists($subfolder) || !JoomDOCFileSystem::exists($folder)) {
return null;
}
return JString::strpos($subfolder, $folder) === 0;
}
