Re: [PATCH] rebase: introduce --update-branches option

From: brian m. carlson <sandals@crustytoothpaste.net>
Date: Sep 3, 2019, 00:50 UTC
Message-ID: <20190903005018.GH11334@genre.crustytoothpaste.net>
In-Reply-To: <20190902234109.2922-1-wh109@yahoo.com>

On 2019-09-02 at 23:41:08, Warren He wrote:

Show 13 quoted lines

> Sometimes people have to rebase multiple related branches. One way to do that
> quickly, when there are branches pointing to ancestors of a later branch (which
> happens a lot if you try hard to pad your PR count on GitHub--I mean if you try
> to make small, logically separate changes), is to rebase that later branch and
> then reset ancestor branches to the rewritten commits. You just have to work
> out which branches correspond to which of the new commits.
> 
> Here's an automated way to update those ancestor branches.
> 
> It's implemented as a function that processes a todo list, modeled after
> `todo_list_add_exec_commands`. Currently steps are added as `exec git branch -f
> <branchname>`, which comes with the caveat that they're not applied atomically
> when it finishes rebasing.

This is an interesting idea, and I definitely would find myself using it. I maintain multiple nested branches for the SHA-256 transition and rebasing tends to be a bit of a hassle. The idea of reordering commits further down into earlier branches using this technique is also appealing.

I like the idea of using existing tooling for this and not needing an additional verb.

My gut tells me folks may want a bit more control over *which* branches are rebased, but I don't have a personal need for that, so I'm not going to request it or propose an interface for it. If nobody else does, then I think we should adopt the simplest approach, which is what you've proposed. Users can always edit the todo list if they find an unexpected branch, after all.

The other thought I had about this is a question about how it performs with many refs. I've worked with a repository with easily 80,000 refs, and I wonder if the current technique will perform adequately there.

I'm interested to hear others' opinions on this series and am looking forward to seeing it progress.

-- 
brian m. carlson: Houston, Texas, US
OpenPGP: https://keybase.io/bk2204