From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 09 Jan 2013 19:55:25 GMT
Subject: Re: [PATCH 10/19] reset --keep: only write index file once
Message-ID: <7vd2xe5dxu.fsf@alter.siamese.dyndns.org>
In-Reply-To: <1357719376-16406-11-git-send-email-martinvonz@gmail.com>

Martin von Zweigbergk <martinvonz@gmail.com> writes:

> "git reset --keep" calls reset_index_file() twice, first doing a
> two-way merge to the target revision, updating the index and worktree,
> and then resetting the index. After each call, we write the index
> file.
>
> In the unlikely event that the second call to reset_index_file()
> fails, the index will have been merged to the target revision, but
> HEAD will not be updated, leaving the user with a dirty index.
>
> By moving the locking, writing and committing out of
> reset_index_file() and into the caller, we can avoid writing the index
> twice, thereby making the sure we don't end up in the half-way reset
> state.

Nice.