Re: [PATCHv2 0/10] pkt-line and remote-curl cleanups server

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 18, 2013, 09:29 UTC
Message-ID: <7vhalaas2b.fsf@alter.siamese.dyndns.org>
In-Reply-To: <20130218091203.GB17003@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

Show 17 quoted lines

> On Sun, Feb 17, 2013 at 05:41:13PM -0800, Jonathan Nieder wrote:
>
>> > I don't think so. Don't ERR lines appear inside their own packets?
>> 
>> Yes, I misread get_remote_heads for some reason.  Thanks for checking.
>
> Thanks for bringing it up. I had not even thought about ERR at all. So
> it was luck rather than skill that I was right. :)
>
>> I'm not sure whether servers are expected to send a flush after an
>> ERR packet.  The only codepath I know of in git itself that sends
>> such packets is git-daemon, which does not flush after the error (but
>> is not used in the stateless-rpc case).  http-backend uses HTTP error
>> codes for its errors.
>
> I just checked, and GitHub also does not send flush packets after ERR.
> Which makes sense; ERR is supposed to end the conversation.

Hmph. A flush packet was supposed to be a mark to say "all the packets before this one can be buffered and kept without getting passed to write(2), but this and all such buffered data _must_ go on the wire _now_". So in the sense, ERR not followed by a flush may not even have a chance to be seen on the other end, no? That is what the comment before the implementation of packet_flush() is all about.