Re: [PATCH 3/8] xread_nonblock: add functionality to read from fds without blocking

Jeff King [off-list ref] writes:

Are we trying to protect ourselves against somebody _else_ giving us a
non-blocking descriptor? In that case we'll quietly spin and waste CPU.
Which isn't great, but perhaps better than returning an error.

I think I said it earlier in a message upthread.

Ahh, there is a difference if the file descriptor the caller feeds
strbuf_read_once() happens to be marked as nonblock.  read_once()
wants to return without doing the poll() in such a case.  Even
though this series would not introduce any use of a nonblocking file
descriptor, as a general API function, [4/8] must be prepared for
such a future caller, hence [3/8] is needed.