That bug is stuck on not breaking exactly this kind of behavior. They cite Dropbox in that thread (though I haven't read the followups yet), who has www.dropbo

That bug is stuck on not breaking exactly this kind of behavior. They cite Dropbox in that thread (though I haven't read the followups yet), who has www.dropboxlocalhost.com resolving to 127.0.0.1. It sounds like Spotify does something similar.