From: Junio C Hamano <gitster@pobox.com>
Date: Fri, 13 Feb 2015 18:27:44 GMT
Subject: Re: [PATCH v2 04/12] ref_transaction_update(): remove "have_old" parameter
Message-ID: <xmqqfva9oee7.fsf@gitster.dls.corp.google.com>
In-Reply-To: <54DE3135.7070902@alum.mit.edu>

Michael Haggerty <mhagger@alum.mit.edu> writes:

> On 02/12/2015 06:32 PM, Junio C Hamano wrote:
>> On Thu, Feb 12, 2015 at 3:12 AM, Michael Haggerty <mhagger@alum.mit.edu> wrote:
>>> Instead, verify the reference's old value if and only if old_sha1 is
>>> non-NULL.
>>>
>>> ...
>>> @@ -3664,9 +3664,6 @@ int ref_transaction_update(struct ref_transaction *transaction,
>>>         if (transaction->state != REF_TRANSACTION_OPEN)
>>>                 die("BUG: update called for transaction that is not open");
>>>
>>> -       if (have_old && !old_sha1)
>>> -               die("BUG: have_old is true but old_sha1 is NULL");
>>> -
>> 
>> In the old world, old_sha1 here used to be one of
>>  (1) NULL, (2) null_sha1[], or (3) a real object name.
>> What is the rule in the new world?
> ...
>     ... If old_sha1 is NULL, then the previous
>     value is not checked.

OK.  That makes it perfectly clear that removing these lines is the
right thing to do.

Thanks.