Re: [PATCH 2/4] rebase: avoid double reflog entry when switching branches

[Junio C Hamano <gitster@pobox.com>]

"Johannes Schindelin via GitGitGadget" <gitgitgadget@gmail.com>
writes:

> From: Johannes Schindelin <johannes.schindelin@gmx.de>
>
> When switching a branch *and* updating said branch to a different
> revision, let's avoid a double entry by first updating the branch and
> then adjusting the symbolic ref HEAD.

Ah, in the original sequence, HEAD is updated twice, leaving two
reflog entries for HEAD (and one for the underlying "switch_to"
branch by virtue of REF_UPDATE_VIA_HEAD).  In the new sequence,
update_ref() updates the underlying "switch_to" and then HEAD, so
we'd get one reflog entry for each of them.

Makes sense.  s/let's avoid a double entry/& in HEAD's reflog/ would
have avoided wasting reader's time who needlessly wondered where
that redundancy came from, though.

>
> Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
> ---
>  builtin/rebase.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/builtin/rebase.c b/builtin/rebase.c
> index e1dfa74ca8..768bea0da8 100644
> --- a/builtin/rebase.c
> +++ b/builtin/rebase.c
> @@ -438,10 +438,11 @@ static int reset_head(struct object_id *oid, const char *action,
>  				 detach_head ? REF_NO_DEREF : 0,
>  				 UPDATE_REFS_MSG_ON_ERR);
>  	else {
> -		ret = create_symref("HEAD", switch_to_branch, msg.buf);
> +		ret = update_ref(reflog_orig_head, switch_to_branch, oid,
> +				 NULL, 0, UPDATE_REFS_MSG_ON_ERR);
>  		if (!ret)
> -			ret = update_ref(reflog_head, "HEAD", oid, NULL, 0,
> -					 UPDATE_REFS_MSG_ON_ERR);
> +			ret = create_symref("HEAD", switch_to_branch,
> +					    reflog_head);
>  	}
>  
>  leave_reset_head: