From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 18 Jun 2014 20:34:41 GMT
Subject: Re: [PATCH v3 01/14] refs.c make ref_transaction_create a wrapper to ref_transaction_update
Message-ID: <xmqqha3ihs7y.fsf@gitster.dls.corp.google.com>
In-Reply-To: <1403111346-18466-2-git-send-email-sahlberg@google.com>

Ronnie Sahlberg <sahlberg@google.com> writes:

> Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
> ---
>  refs.c | 13 ++-----------
>  refs.h |  7 ++++---
>  2 files changed, 6 insertions(+), 14 deletions(-)
>
> diff --git a/refs.c b/refs.c
> index dfbf003..a9f91ab 100644
> --- a/refs.c
> +++ b/refs.c
> @@ -3487,23 +3487,14 @@ int ref_transaction_create(struct ref_transaction *transaction,
>  			   int flags, const char *msg,
>  			   struct strbuf *err)
>  {
> -	struct ref_update *update;
> -
>  	if (transaction->state != REF_TRANSACTION_OPEN)
>  		die("BUG: create called for transaction that is not open");
>  
>  	if (!new_sha1 || is_null_sha1(new_sha1))
>  		die("BUG: create ref with null new_sha1");
>  
> -	update = add_update(transaction, refname);
> -
> -	hashcpy(update->new_sha1, new_sha1);
> -	hashclr(update->old_sha1);
> -	update->flags = flags;
> -	update->have_old = 1;
> -	if (msg)
> -		update->msg = xstrdup(msg);
> -	return 0;
> +	return ref_transaction_update(transaction, refname, new_sha1,
> +				      null_sha1, flags, 1, msg, err);
>  }

Hmmm.

This probably logically belongs to the end of the previous series
and not necessarily tied to reflog transaction, no?

At the beginning of ref_transaction_update() there also is the same
guard on transaction->state, and having both feels somewhat iffy.
Of course it will give a wrong BUG message if we removed the check
from this function, so perhaps the code is OK as-is.

>  int ref_transaction_delete(struct ref_transaction *transaction,
> diff --git a/refs.h b/refs.h
> index db463d0..495740d 100644
> --- a/refs.h
> +++ b/refs.h
> @@ -283,9 +283,10 @@ struct ref_transaction *ref_transaction_begin(struct strbuf *err);
>  /*
>   * Add a reference update to transaction.  new_sha1 is the value that
>   * the reference should have after the update, or zeros if it should
> - * be deleted.  If have_old is true, then old_sha1 holds the value
> - * that the reference should have had before the update, or zeros if
> - * it must not have existed beforehand.
> + * be deleted.  If have_old is true and old_sha is not the null_sha1
> + * then the previous value of the ref must match or the update will fail.
> + * If have_old is true and old_sha1 is the null_sha1 then the ref must not
> + * already exist and a new ref will be created with new_sha1.
>   * Function returns 0 on success and non-zero on failure. A failure to update
>   * means that the transaction as a whole has failed and will need to be
>   * rolled back.