From: Junio C Hamano <gitster@pobox.com>
Date: Tue, 03 Mar 2009 00:57:45 GMT
Subject: Re: [PATCH] rebase -i: avoid 'git reset' when possible
Message-ID: <7v1vtfl8xi.fsf@gitster.siamese.dyndns.org>
In-Reply-To: <alpine.DEB.1.00.0903012242180.10279@pacific.mpi-cbg.de>

Johannes Schindelin <Johannes.Schindelin@gmx.de> writes:

> Or even
>
> 	current=$ONTO
> 	fd=3
> 	while read command sha1 rest
> 	do
> 		case "$fd,$command,$current" in
> 		3,pick,"$sha1"*|t,p,"$sha1"*)
> 			current=$sha1
> 			;;
> 		*)
> 			fd=1
> 			;;
> 		esac
> 		echo "$command $sha1 $rest" >&$fd
> 	done < "$TODO" > "$TODO.new" 3>> "$DONE" &&
> 	mv "$TODO.new" "$TODO"
>
> Hmm?

Certainly.

Even though "3 means we haven't found a non-pick yet" feels slightly
hacky, the logic is contained in this small loop and I do not see it as a
problem.  As long as you are sure $ONTO and all sha1 can be compared
without running them through rev-parse, avoiding rev-parse per iteration
is a very attractive optimization.