put {} back info if blocks because that's actually good idea

assert is before loop now

add assert

In D54759#1251338, @kevans wrote:

I'm not sure I'm convinced that dir is actually always set, but I haven't spent that much time reading the above logic. An assertion on that here might be good to try and do something useful instead of infinitely looping, but I don't insist

i was thinking of that already. that there must be way to run that while loop once with stream == 0. this is even better maybe as it shoots first and asks questions later. maybe it fits as there's no extra useless check. anyway i was always like how about an Actual C Coder (TM) *also* reviewing this

In D54734#1250682, @adrian wrote:

The manpage could do with a bit more work but we can work on that a bit after landing. Lemme get some more eyeballs on this.