From: Martin von Zweigbergk <martin.von.zweigbergk@gmail.com>
Date: Wed, 18 Jul 2012 07:16:47 GMT
Subject: Re: [PATCH v8 4/4] git-rebase: add keep_empty flag
Message-ID: <CAOeW2eHvDMkX++L386aXaUsMPVbmL-9GvioiUAPGX8PjJ8TNTA@mail.gmail.com>
In-Reply-To: <5006614E.8090601@viscovery.net>

On Wed, Jul 18, 2012 at 12:10 AM, Johannes Sixt <j.sixt@viscovery.net> wrote:
> Am 7/18/2012 8:20, schrieb Martin von Zweigbergk:
>> On Fri, Apr 20, 2012 at 7:36 AM, Neil Horman <nhorman@tuxdriver.com> wrote:
>>>  pick_one () {
>>>         ff=--ff
>>> +
>>>         case "$1" in -n) sha1=$2; ff= ;; *) sha1=$1 ;; esac
>>>         case "$force_rebase" in '') ;; ?*) ff= ;; esac
>>>         output git rev-parse --verify $sha1 || die "Invalid commit name: $sha1"
>>> +
>>> +       if is_empty_commit "$sha1"
>>> +       then
>>> +               empty_args="--allow-empty"
>>> +       fi
>>> +
>>>         test -d "$rewritten" &&
>>>                 pick_one_preserving_merges "$@" && return
>>> -       output git cherry-pick $ff "$@"
>>> +       output git cherry-pick $empty_args $ff "$@"
>>
>> The is_empty_commit check seems to mean that if $sha1 is an "empty"
>> commit, we pass the --allow-empty option to cherry-pick. If it's not
>> empty, we don't. The word "allow" in "allow-empty" suggests that even
>> if the commit is not empty, cherry-pick would not mind. So, can we
>> always pass "allow-empty" to cherry-pick (i.e. even if the commit to
>> pick is not empty)?
>
> I don't think so. If the commit is not empty, but all its changes are
> already in HEAD, then it will become "empty" when cherry-picked to HEAD.
> In such a case, we usually do not want to record an empty commit, but stop
> rebase to give to user a chance to deal with the situation.

Ah, makes sense. Thanks!