Re: [PATCH v5 2/3] branch: Mark and color a branch differently if it is checked out in a linked worktree

From: Nickolai Belakovski <nbelakovski@gmail.com>
Date: Jan 13, 2019, 01:41 UTC
Message-ID: <CAC05384uh_xRboFhxohRq-vKFrTPDnszSaS3vW+BAv30h-Zd+g@mail.gmail.com>
In-Reply-To: <e313d0b1-54b1-9fe2-6c75-d2ae7b57fe3a@iee.org>

On Thu, Jan 10, 2019 at 1:43 PM Philip Oakley <philipoakley@iee.org> wrote:

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>
> On 07/01/2019 19:04, Junio C Hamano wrote:
> > I do not think it is warranted to paint the safety features as
> > "limitations".
>
> Is this not just a case of needing to clarify that this is 'safety'
> related to the _users_ mental model (or lack of) relative to the limited
> information that was previously given by the branch command's list.
>
> You are right that there is no data safety issue, but users make
> mistakes when they misunderstand the situation.

Not trying to paint anything one way or another. I found that these features got in the way of my workflows and didn't see any immediate reason why they had to exist. Thinking about it a bit more, is it unreasonable to delete a branch even if it's checked out in a worktree as long as the user uses git branch --delete --force or -D? This would leave the worktree in a detached head state, but all the data would be untouched. The output of deletion could mention that the branch had been checked out in a worktree so that the user is fully informed.

Checking out the same branch in two worktrees should be technically possible to implement safely, but I don't see a use case for having the same branch checked out in multiple worktrees anyway. Why use multiple worktrees at that point? If a user really wants the same contents in two directories they can work around this limitation/safety feature by just making another branch pointing at the same commit. But anyway I'm just explaining why I chose the word 'limitation'.

Show 5 quoted lines

> >    If you do want to remove that branch,
> > you need to go to that worktree that has a checkout of that branch,
> > check out a different branch there, and then remove it.  Again,
> > knowing where that other worktree is is the fist thing you need to
> > know.

This just seems silly to me when git branch --delete has a --force option. But that's off topic.

Show 23 quoted lines

> >
> >> The git worktree list command contains the relevant information, however
> >> this is a much less frquently used command than git branch.
> > It is not a good justification.  If the "relevant information" given
> > by the command is necessary one, the user can run that command.  If
> > the situation where that "relevant information" becomes necessary is
> > rare, the command is run much less frequently is not a problem---it
> > is expected.  And overloading a more frequently used command with
> > information that is less frequently wanted is actually not a great
> > design.
> But leaving the older command unaware of the newer developments and the
> user unwise as to its missing info is equally a poor situation.
> >
> > A more relevant justification may be that even though the
> > information can already be found in "worktree list" output, it would
> > give us flexibility in presentation to allow the custom format in
> > for-each-ref to show it.
> >
> > So, I am between moderately Meh to fairly negative on this step; Meh
> > in the sense that "thanks to the previous step, we _could_ do this,
> > it does not give incorrect information, and it makes the output more
> > cheerful, but it does not add that much useful and actionable piece
> > of information".

Allow me to add some color to my original commit message. The point of this patch is so that the user is not surprised when they see the message that this branch is checked out in another worktree when trying to delete it or check it out, since they have presumably run git branch recently and seen the formatted output indicating that a branch they may want to delete/checkout is checked out in a worktree. This was my frustration that prompted me to dive into this in the first place - I'm cleaning up my branches and all of a sudden git decides it doesn't want to let me delete one because it's checked out somewhere else, even though I know I don't care about it because I know the branch has already been merged upstream, or is old, or whatever. I thought, if git branch output could at least let me know that it's going to treat some branches differently, I can be proactive about things and go to my worktree and delete the branch, or skip trying to clean it up or not check it out.

I'll pursue the above-mentioned topic of allowing git branch -D to allow the user to delete branches checked out in a worktree separately, but even if that goes through, I think this patch would still be useful in that it tells me that I can't check out the branches that are colored in cyan.

Does that make more sense?