threads / discuss / 47889

I'm trying to break "git pull --rebase"

Subject: I'm trying to break "git pull --rebase"

## tl;dr

3 messages between Feb 20, 2018 and Feb 20, 2018.

replies: 2people: 3as markdown or json

Julius Musseau· Feb 20, 2018, 22:00 UTC · lore

Hi, Git Developers,

I'm currently writing a blog post about "git pull --rebase". The point of the blog post is to examine scenarios where two people are working together on a short-lived feature branch, where history rewrites are allowed, and where both are using "git pull --rebase" to stay in sync with each other.

I was hoping to concoct a situation where "git pull --rebase" makes a mess of things.

So far I have been unable to do this. I tried version v1.7.2 of Git as well as version v2.14.1, and as far as I can tell, "git pull --rebase" is bulletproof.

Does anyone here happen to know a situation where "git pull --rebase" makes a mess?

Here's a draft of the blog post:

Title:  "(Too much) fun with git pull --rebase"

https://mergebase.com/doing-git-wrong/2018/02/17/fun-with-git-pull-rebase/

Here are the "git pull --rebase" scenarios I've tested so far:

1.  origin/feature rebased against origin/master

2.  origin/feature squash-merged against origin/master

3.  origin/feature squashed in-place`

4.  origin/feature dropped a commit

5.  origin/feature insanity (adjusted merge-base, reversed commits,
squashed some commits)

6.  undo of 5

So far "git pull --rebase" does the exact right thing in every case!

If anyone knows a scenario where "git pull --rebase" fails to do the right thing, I would be very grateful to hear of it.

Thanks!

yours sincerely,

Julius Musseau

Stefan Beller· Feb 20, 2018, 22:08 UTC · re: Julius Musseau · lore

Re: I'm trying to break "git pull --rebase"

On Tue, Feb 20, 2018 at 2:00 PM, Julius Musseau <julius@mergebase.com> wrote:

Show 17 quoted lines

> Hi, Git Developers,
>
> I'm currently writing a blog post about "git pull --rebase".   The
> point of the blog post is to examine scenarios where two people are
> working together on a short-lived feature branch, where history
> rewrites are allowed, and where both are using "git pull --rebase" to
> stay in sync with each other.
>
> I was hoping to concoct a situation where "git pull --rebase" makes a
> mess of things.
>
> So far I have been unable to do this.  I tried version v1.7.2 of Git
> as well as version v2.14.1, and as far as I can tell, "git pull
> --rebase" is bulletproof.
>
> Does anyone here happen to know a situation where "git pull --rebase"
> makes a mess?

If you are inclined to experiment with submodules, I would have an easy answer for you. :)

But instead of giving an answer myself (as I love reading about things the usual mailing list folks miss), maybe this is a good starting point to poke at things https://github.com/git/git/commit/a6d7eb2c7a6a402a938824bcf1c5f331dd1a06bb

For the non-submodule use case, I would think pull is pretty solid, as you lay out in your blog draft.

(If you finish by Wednesday 21st), you may be interested in submitting to Git rev-news (or a later edition if you take time writing) https://public-inbox.org/git/CAP8UFD1HPruE3N_0k8_TFreBML9V8K=SS8LqD-XkeEuheSmGvw@mail.gmail.com/

Thanks, Stefan

Martin Langhoff· Feb 20, 2018, 22:21 UTC · re: Julius Musseau · lore

Re: I'm trying to break "git pull --rebase"

On Tue, Feb 20, 2018 at 5:00 PM, Julius Musseau <julius@mergebase.com> wrote:

> I was hoping to concoct a situation where "git pull --rebase" makes a
> mess of things.

It breaks quite easily with some workflows. They are all in the "don't do that" territory.

Open a long-lived feature-dev branch, work on it. Other folks are working on master. Merge master into feature-dev. Make sure some merges might need conflict resolution.

Reorg some code on master, move files around. Code some more on feature-dev branch. Merge master into feature-dev; the merge machinery will probably cope with the code move, file renames. If it doesn't, resolve it by hand.

Let all that simmer for a little bit.

Then try to rebase.

"Doctor, it hurts when I rebase after merging with conflict resolution... "

cheers,