Re: [PATCH] sequencer: honor GIT_REFLOG_ACTION

> Hi Phillip,
> 
> On Thu, Apr 2, 2020 at 2:25 AM Phillip Wood <phillip.wood123@gmail.com> wrote:
>>
>> Hi Elijah
>>
>> Thanks for fixing this
>>
>> On 01/04/2020 21:31, Elijah Newren via GitGitGadget wrote:
>>> From: Elijah Newren <newren@gmail.com>
>>>
>>> There is a lot of code to honor GIT_REFLOG_ACTION throughout git,
>>> including some in sequencer.c; unfortunately, reflog_message() and its
>>> callers ignored it.  Instruct reflog_message() to check the existing
>>> environment variable, and use it when present as an override to
>>> action_name().
>>>
>>> Also restructure pick_commits() to only temporarily modify
>>> GIT_REFLOG_ACTION for a short duration and then restore the old value,
>>> so that when we do this setting within a loop we do not keep adding "
>>> (pick)" substrings and end up with a reflog message of the form
>>>       rebase (pick) (pick) (pick) (finish): returning to refs/heads/master
>>>
>>> Signed-off-by: Elijah Newren <newren@gmail.com>
>>> ---
>>>       sequencer: honor GIT_REFLOG_ACTION
>>>
>>>       I'm not the best with getenv/setenv. The xstrdup() wrapping is
>>>       apparently necessary on mac and bsd. The xstrdup seems like it leaves us
>>>       with a memory leak, but since setenv(3) says to not alter or free it, I
>>>       think it's right. Anyone have any alternative suggestions?
>>>
>>> Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-746%2Fnewren%2Fhonor-reflog-action-in-sequencer-v1
>>> Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-746/newren/honor-reflog-action-in-sequencer-v1
>>> Pull-Request: https://github.com/git/git/pull/746
>>>
>>>    sequencer.c               |  9 +++++++--
>>>    t/t3406-rebase-message.sh | 16 ++++++++--------
>>>    2 files changed, 15 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/sequencer.c b/sequencer.c
>>> index e528225e787..5837fdaabbe 100644
>>> --- a/sequencer.c
>>> +++ b/sequencer.c
>>> @@ -3708,10 +3708,11 @@ static const char *reflog_message(struct replay_opts *opts,
>>>    {
>>>        va_list ap;
>>>        static struct strbuf buf = STRBUF_INIT;
>>> +     char *reflog_action = getenv("GIT_REFLOG_ACTION");
>>
>> Minor nit - you're using a string here rather that the pre-processor
>> constant that is used below
> 
> Yeah, true.  However, using a mixture of both styles is consistent
> with the current code's inconsistency about which one should be used.
> :-)

>>>        va_start(ap, fmt);
>>>        strbuf_reset(&buf);
>>> -     strbuf_addstr(&buf, action_name(opts));
>>> +     strbuf_addstr(&buf, reflog_action ? reflog_action : action_name(opts));
>>>        if (sub_action)
>>>                strbuf_addf(&buf, " (%s)", sub_action);
>>>        if (fmt) {
>>> @@ -3799,8 +3800,10 @@ static int pick_commits(struct repository *r,
>>>                        struct replay_opts *opts)
>>>    {
>>>        int res = 0, reschedule = 0;
>>> +     char *prev_reflog_action;
>>>
>>>        setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
>>> +     prev_reflog_action = xstrdup(getenv(GIT_REFLOG_ACTION));
>>
>> I'm confused as to why saving the environment variable immediately after
>> setting it works but the test shows it does - why doesn't this clobber
>> the value of GIT_REFLOG_ACTION set by the user?
> 
> The third parameter, 0, means only set the environment variable if
> it's not already set.