I've also explained this in another comment, but basically, the call to `normpath` in his code takes care of this, e.g. >>> normpath('ExistingDir/../../pa

I've also explained this in another comment, but basically, the call to `normpath` in his code takes care of this, e.g. >>> normpath('ExistingDir/../../parentRestrictedDir/passwords') '../parentRestrictedDir/passwords'