kdiroperator: fix full file path not being stripped
QDir::isReadable always returns true for an unknown path if the parent folder is readable, so use QFileInfo::isReadable instead.
Need to use QUrl::StripTrailingSlash and QUrl::RemoveFilename separately since in QUrlPrivate::appendPath, QUrl::RemoveFilename is done before QUrl::StripTrailingSlash.
BUG: 459900 FIXED-IN: 5.102