Re: t5401-update-hooks test failure

["Shawn O. Pearce" <spearce@spearce.org>]

Nicolas Pitre <nico@fluxnic.net> wrote:
> On Tue, 9 Feb 2010, Shawn O. Pearce wrote:
> > 
> > builtin-send-pack.c clearly isn't stopping early while processing
> > the stream, since we see later messages from the post-receive and
> > post-update hooks just fine.
> > 
> > So I think the only code that is in question is the case 2 arm of
> > recv_sideband().  But to be honest, I can't find any fault with it.
> 
> Note that strict order of messages passed through the sideband can't be 
> relied upon.  Often you have sideband 1 connected to stdin and sideband 
> 2 connected to stderr,

Oh.  Sure.  But that isn't really the case here.

The messages are all coming down side band #2, before we write
anything down side band #1.  The missing message in question
should have appeared somewhere in the middle of that side band
#2 stream that we are seeing in the test output.  Given that its
all serialized down into a single stream by the parent process
receive-pack, we really shouldn't see the messages out of order.


> and they are linked with pipes, and various 
> factors such as stdio buffering or even printf implementation in the C 
> lib

The only way I can see this missing message happening is if the C
library isn't flushing the stdio buffer before the hook process
exits.  Given that the hook process is a /bin/sh shell script,
and its using echo to print its messages... I'm at a loss for how
to fix that in Git.

Unless its the recv_sideband() somehow skipping a line.  But I
can't see it doing that.

-- 
Shawn.