From: Johannes Sixt <j6t@kdbg.org>
Date: Fri, 20 Apr 2012 16:45:34 GMT
Subject: Re: [PATCH] rebase -i: avoid checking out $branch when possible
Message-ID: <4F9192AE.5050304@kdbg.org>
In-Reply-To: <fee3225e29915e1b61e29a5d2fe37db20fa4b596.1334933837.git.trast@student.ethz.ch>

Am 20.04.2012 17:05, schrieb Thomas Rast:
> The command
> 
>   git rebase [-i] [--onto $onto] $base $branch
> 
> is defined to be equivalent to
> 
>   git checkout $branch && git rebase [-i] [--onto $onto] $base
> 
> However, we do not have to actually perform the checkout.  The rebase
> starts building on top of $base (or $onto, if given).  The tree
> _state_ (not diff) of $branch is irrelevant.  Actually performing the
> checkout has some downsides: $branch may potentially be way out of
> touch with HEAD, and thus e.g. trigger a full rebuild in a timestamp-
> based build system, even if $base..$branch only edits the README.

Thanks, this is very much appreciated. I like it (because it would
prevent lots of unneeded rebuilds in my use-cases).

>  cp "$todo" "$todo".backup
>  git_sequence_editor "$todo" ||
> -	die_abort "Could not execute editor"
> +	die_abort_with_checkout "Could not execute editor"

I don't think that we want to checkout here, even if the docs say we do.

-- Hannes