forked from mirrors/jj
b64ee147ae
We used to have documention about how conflicts are implemented, but I removed that a long time ago when I rewrote the README to target users rather than VCS hackers. Let's have a doc for the VCS hackers (and curious users) as well, though.
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2.5 KiB
First-class conflicts
Introduction
Like Pijul and Darcs but unlike most other VCSs, Jujutsu can record conflicted states in commits. For example, if you rebase a commit and it results in a conflict, the conflict will be recorded in the rebased commit and the rebase operation will succeed. You can then resolve the conflict whenever you want. Conflicted states can be further rebased, merged, or backed out. Note that what's stored in the commit is a logical representation of the conflict, not conflict markers; rebasing a conflict doesn't result in a nested conflict markers (see technical doc for how this works).
Advantages
The deeper understanding of conflicts has many advantages:
- Removes the need for things like
git rebase/merge/cherry-pick/etc --continue. Instead, you get a single workflow for resolving conflicts: check out the conflicted commit, resolve conflicts, and amend. - Enables the "auto-rebase" feature, where descendants of rewritten commits automatically get rewritten. This feature mostly replaces Mercurial's Changeset Evolution.
- Lets us define the change in a merge commit as being compared to the merged parents. That way, we can rebase merge commits correctly (unlike both Git and Mercurial). That includes conflict resolutions done in the merge commit, addressing a common use case for git rerere. Since the changes in a merge commit are displayed and rebased as expected, evil merges are arguably not as evil anymore.
- Allows you to postpone conflict resolution until you're ready for it. You can easily keep all your work-in-progress commits rebased onto upstream's head if you like.
- Criss-cross merges and octopus merges become trivial (implementation-wise); some cases that Git can't currently handle, or that would result in nested conflict markers, can be automatically resolved.
- Enables collaborative conflict resolution. (This assumes that you can share the conflicts with others, which you probably shouldn't do if some people interact with your project using Git.)
For information about how conflicts are handled in the working copy, see here.