Re: [PATCH 0/5] bisect: Add support for a --no-checkout option.

From: Jon Seymour <jon.seymour@gmail.com>
Date: Aug 2, 2011, 01:15 UTC
Message-ID: <CAH3AnrrrvX64s3p_=5mrVcwx5FeO0iT8uX47remyCuCwPpOo=A@mail.gmail.com>
In-Reply-To: <7vaabshfmb.fsf@alter.siamese.dyndns.org>

On Tue, Aug 2, 2011 at 9:33 AM, Junio C Hamano <gitster@pobox.com> wrote:

Show 30 quoted lines

> Jon Seymour <jon.seymour@gmail.com> writes:
>
>> On Tue, Aug 2, 2011 at 3:33 AM, Junio C Hamano <gitster@pobox.com> wrote:
>>> Jon Seymour <jon.seymour@gmail.com> writes:
>>>
>>>> It might become more important if someone ever writes a tool that does
>>>> a bisection on the user's behalf. In this case, aborting the tool
>>>> might leave the HEAD in, what appears to the user, a confused state.
>> ...
>> In this hypothetical additional series, are you happy for
>> --no-checkout to become a synonym for --update-ref=HEAD in the manner
>> of v8? From a technical perspective, it doesn't seem necessary to
>> duplicate the state variables and parameters.
>
> Well, from a technical perspective, which ref is to be updated is an
> option that is valid _only_ under no-checkout mode, and no-checkout mode
> could be using HEAD, so I think you would need two variables. One for
> "what mode are we running", and the other that is only valid under "we are
> in no-checkout mode" that says "we update BISECT_HEAD".
>
> If no-checkout mode _never_ updates HEAD, because the normal mode _always_
> updates HEAD, you could reduce them into a single variable (i.e. if we are
> updating HEAD then we are in normal mode, otherwise we are in no-checkout
> mode).  I actually have a mild suspicion that the no-checkout mode may
> turn out to be too confusing for people if it by default updates HEAD, and
> we may want to have it update something that is not HEAD by default (or
> forbid --update-ref from specifying HEAD), so if that turns out to be the
> approach we are going to proceed, we _might_ end up needing only one
> variable, but I do not think we know it just yet.  At least I don't.
>

How about in the current series, I change the option parsed by bisect--helper.c to be:

    --bisect-mode=checkout|update-ref

The porcelain option can still be --no-checkout (or should it be --bisect-mode too?). The porcelain will maintain a state variable called (rather than BISECT_NO_CHECKOUT).

     BISECT_MODE

Then, the next series can add a --bisect-head option (instead of --update-ref) to allow the head to be varied (defaulting to BISECT_HEAD) if not specified.

Sound ok?

jon.