You're right about r/strip(), thanks (new patch in attachment).

> In your test you're checking whether returned facts 
> contain every requested fact, this is not guaranteed by RFC.

Yes, but we're using a dummy FTP server returning static MLSD_DATA, so this is not important.

> Also, not sure what the last for statement 
> is supposed to mean. Is it a typo?

It makes sure whether in case of directory empty (see: no data returned) we don't enter in the "for" block.
Probably it's not even necessary because this is already tested by:
self.assertRaises(StopIteration, next, self.client.mlsd())
...but... whathever.