[BeetleB]

I would think the obvious answer is how jj deals with merge conflicts.

In git, if you get a conflict, you feel like you have to resolve it now.

With jj, most of the times I get merge conflicts, I simply ignore them and deal with them later. A conflict is not at all a blocker.

[nocman]

> In git, if you get a conflict, you feel like you have to resolve it now.

I guess I view that as a positive rather than a negative. I'm not saying that dealing with merge conflicts is a picnic -- it isn't. I just find it difficult to believe that ignoring them and resolving them later will improve the situation in the long run.

[hellcow]

It's not about "ignoring" conflicts. In jj you're often working with stacked diffs, and merge conflicts can impact a dozen "branches" all at once. This is trivial to resolve in jj and a nightmare in git. It lets you work on them one piece at a time and upon resolving it, instantly see the conflicts fixed across all your branches at once.

[steveklabnik]

It’s about giving you choice. If you want to then fix them immediately, you can. But you don’t have to if you don’t want to.

But really, it’s about something deeper: rebase is a first-class operation in memory, and not a serious of patch applications via the file system. They’re therefore lightning quick, and will always succeed, which is nice. If you get partway through resolving a conflict and want to change to something else for some reason, that’s possible and simple.

[MrJohz]

I think the word "later" is unhelpful in this situation because it implies all sorts of different timescales. You don't want to be resolving merge conflicts three weeks after you've created them, you're right!

Typically for me, "later" means "immediately after the rebase command has finished", which is very similar to git's "while the rebase command is running", but has some subtle and important differences.

For example, because the rebase completes first, I get to see roughly what the end-state of the rebase is before I start doing the hard work of fixing conflicts. This is useful as a sanity check - sometimes the reason I'm getting a bunch of merge conflicts is because I was rebasing the wrong things in the first place and included an extra commit somewhere. Seeing the result first gives me the chance to sanity check what I'm doing.

Another thing is that my repository is never in a broken state where I can't continue doing other things. There's no way in git to stash a rebase, say because I've realised a different approach might work better or just because I urgently need to work on something different. I either need to cancel the rebase and start it again later, or keep on going until it's over. In jj, because the conflicts are automatically checked in as part of the commits, I can easily jump backwards and forwards between the work I'm doing resolving my conflicts, and anything else.

Another way of thinking about it is that git is very modal. You check out a branch and are in the "branch" mode, and then you start a rebase and are in the "rebase" mode, and then you do a bisection and are in the "bisect" mode - it's difficult to move freely between these modes, and there's certain things you can only do in some modes and can't do in others. In contrast, jj has exactly one mode: "there is a commit checked out". The different operations like rebasing all happen atomically, so you never see the halfway state. But because things like conflicts can be encoded in the commit itself, you still have all the same power that the modal approach had, just with a simpler conceptual model.

[raylu]

the thing about rebasing/cherry-picking (including just popping the stash) in git is that you only have 2 choices: fix the conflict now or abandon the entire rebase/cherry-pick

with jj, you have the option to fix half of it and come back later. you can take a look and see how bad the conflicts are if you go a certain route and compare to another option

[skydhash]

Are you using your editor or a special software/plugin for resolving conflicts. I used Sublime Merge in the patch, but now I’m using Magit+ediff. Resolving conflicts is quite trivial in that case. And I can always ‘rebase -i’ to revert some of the decisions I’ve taken.

[touristtam]

> With jj, most of the times I get merge conflicts, I simply ignore them and deal with them later.

Sorry? You what? How do you know which bit from which source goes where?

[BeetleB]

Here's a typical scenario.

You do a git pull, just so your branch isn't so out of sync. Immediately you get merge conflicts. You then tell jj "Hey, I'll deal with this later", and make a branch off of the last commit that was conflict free and continue your work there. jj stores the conflict as is, but your branch is conflict free.

When you feel you have the energy to deal with the conflict, you switch to the branch that has the conflict, and fix the issue(s). Then you can manipulate the graph (rebase, whatever) so you can have everything in one branch - your changes and the changes you pulled in.

[EMM_386]

> When you feel you have the energy to deal with the conflict

So you just kick the can down the road and end up with possibly an even more difficult conflict resolution?

[BeetleB]

> So you just kick the can down the road and end up with possibly an even more difficult conflict resolution?

That sentiment is true for pretty much anything in life one may decide to defer till later :-)

More concretely, it's often not hard to tell if deferring it will make it worse, or merely the same.

The whole point of version control is to give your mind some peace in not worrying about things ("Let's make this change and we can always revert if it doesn't work out"). Conflicts are no different. There's no fundamental reason a conflict needs to be treated like an emergency.

[sunshowers]

Or none at all, if you decide to abandon that work (as has happened to me a bunch).

[MangoToupe]

Isn't this equivalent to simply hard resetting to before the pull? (Or the commit before the conflict?) Plus then you don't end up with an extraneous branch.

[1718627440]

So you essentially do a fast-forward until the first commit with a merge commit and then take the previous one?

Sounds like something that could also become a flag for git merge.

[riwsky]

No. The GP making a commit off of the first non-conflict isn’t the essence of the feature he’s talking about, just an example of what he can do next.

He’d also be free to edit upstream to not commit, or split a change in two so that parts unrelated to the conflict are in their own change. The big idea is that he doesn’t need to blindly decide that before seeing what the conflict is.

[steveklabnik]

Git won’t let the portion of the branch that’s still conflicted remain in conflict while you go and work on the other part.

[1718627440]

I would just abort the conflict resolution.

[steveklabnik]

Then you’re back to the state before the rebase. Which is fine, the point is just that they’re not equivalent!