Re: [PATCH 1/6] t0080: move expected output to a file

From: Jeff King <peff@peff.net>
Date: Jul 2, 2024, 00:57 UTC
Message-ID: <20240702005743.GB27170@coredump.intra.peff.net>
In-Reply-To: <xmqqcynwu1h6.fsf@gitster.g>

On Mon, Jul 01, 2024 at 04:38:45PM -0700, Junio C Hamano wrote:

Show 11 quoted lines

> > I just (re-)posted it in:
> >
> >   https://lore.kernel.org/git/20240701220815.GA20293@coredump.intra.peff.net/
> >
> > so you can see the improvement in some other real cases.
> 
> ;-)
> 
> The shells we care about (and that does not include the /bin/sh on
> ancient Solaris ☹) should be OK, but "IFS= read -r line" somehow
> makes me feel nervous.  Maybe I am superstitious.

I don't know offhand of any case where it will fail. I'd prefer to start with it and see if it bites us, given that it saves us a process invocation per test (and those do add up in some cases).

I also wondered if we might be able to save the syscall-per-byte overhead of "read" for some shells (since we know we are reading until EOF anyway). Using "read -N" with bash would let us do that, but obviously we'd still need to fall back to regular "read" for other shells. I don't think it's worth the complexity unless we can really show a measurable speedup (and I didn't seem to see one).

-Peff