Re: [PATCH v2] branch: implement shortcut to delete last branch

[git@matthieu-moy.fr]

Thanks for Cc-ing me, and sorry for not being very responsive these
days :-\.

Jeff King writes:

> On Fri, Mar 23, 2018 at 10:40:34PM +0000, Aaron Greenberg wrote:
>
>> I can appreciate Matthieu's points on the use of "-" in destructive
>> commands. As of this writing, git-merge supports the "-" shorthand,
>> which while not destructive, is at least _mutative_. Also,
>> "git branch -d" is not destructive in the same way that "rm -rf" is
>> destructive since you can recover the branch using the reflog.
>
> There's a slight subtlety there with the reflog, because "branch -d"
> actually _does_ delete the reflog for the branch. By definition if
> you've found the branch with "-" then it was just checked out, so you at
> least have the old tip. But the branch's whole reflog is gone for good.
>
> That said, I'd still be OK with it.

I don't have objection either.

Anyway, we're supporting this "-" shortcut in more and more commands
(partly because it's a nice microproject, but it probably makes sense),
so the "consistency" argument becomes more and more important, and is
probably more important than the (relative) safety of not having the
shortcut.

>> One thing to consider is that approval of this patch extends the
>> implementation of the "-" shorthand in a piecemeal, rather than
>> consistent, way (implementing it in a consistent way was the goal of
>> the patch set you mentioned in your previous email.) Is that okay? Or
>> is it better to pick up the consistent approach where it was left?
>
> I don't have a real opinion on whether it should be implemented
> everywhere or not. But IMHO it's OK to do it piecemeal for now either
> way, unless we're really sure it's time to move to respecting it
> everywhere. Because we can always convert a
> piecemeal-but-covers-everything state to centralized parsing as a
> cleanup.

Not sure whether it's already been mentionned here, but a previous
attempt is here:

  https://public-inbox.org/git/1488007487-12965-1-git-send-email-kannan.siddharth12@gmail.com/

My understanding is that the actual code is quite straightforward, but
1) it needs a few cleanup patches to be done correctly, and 2) there are
corner-cases to deal with like avoiding a commit message like "merge
branch '-' into 'foo'". Regarding 2), any piecemeal implementation with
proper tests is a step in the right direction.

--
Matthieu Moy
https://matthieu-moy.fr/