Re: [PATCH] push: disable lazy --force-with-lease by default

From: Stefan Beller <sbeller@google.com>
Date: Jul 10, 2017, 22:32 UTC
Message-ID: <CAGZ79ka3ZA_9kE+b=bC28dG5fW3REgC0Ecfn7vie1eRiExxOjg@mail.gmail.com>
In-Reply-To: <xmqqk23ldwbv.fsf@gitster.mtv.corp.google.com>

On Thu, Jul 6, 2017 at 3:39 PM, Junio C Hamano <gitster@pobox.com> wrote:

Show 19 quoted lines

> Stefan Beller <sbeller@google.com> writes:
>
>>> diff --git a/Documentation/git-push.txt b/Documentation/git-push.txt
>>> index 0a639664fd..1fa01210a2 100644
>>> --- a/Documentation/git-push.txt
>>> +++ b/Documentation/git-push.txt
>>> @@ -212,8 +212,9 @@ must not already exist.
>>>  +
>>>  Note that all forms other than `--force-with-lease=<refname>:<expect>`
>>>  that specifies the expected current value of the ref explicitly are
>>> -still experimental and their semantics may change as we gain experience
>>
>> This indicates that this feature is not 'experimental' any more, but disabled
>> (for safety reasons as described below). This implies we will not change the
>> heuristic for push.allowLazyForceWithLease easily.
>
> I actually wanted to say it was a failed experiment, but I see your
> point.  Let's leave the "still experimental" label.
>

After rethinking this feature and how to make it safer, we could actually *ask* the user to confirm the sha1:

    # implicit lease:
    $ git push --force-with-lease <remote/refspec>
    # either do an implicit fetch for the refspec first
    # or use the remote tracking branch:
    This would lose HEAD=27956ac767, including
    the following commits on <remote/refspec> :
    27956ac767 Merge branch 'js/rebase-i-final' into pu
    a1b1c5eb04 Merge branch 'sb/hashmap-cleanup' into pu
    ... and 13 more
    Confirm to lose commits by typing yes: yes
    ... normal push

But that may be more effort than this patch originally intended to be, but I would think this makes the lease effective.

Downside is the I/O (Have we any command that is taking user input as such? -p option for reset/add may come to mind) and the unfriendlyness to scripts, but scripting may rely on the non-lazy form of leases.