Hi,
over recent months I've been playing around with Jujutsu quite
frequently. While I still prefer using Git, there's been a couple
features in it that I really like and that I'd like to have in Git, as
well.
A copule of these features relate to history editing. Most importantly,
I really dig the following commands:
- jj-abandon(1) to drop a specific commit from your history.
- jj-absorb(1) to take some changes and automatically apply them to
commits in your history that last modified the respective hunks.
- jj-split(1) to split a commit into two.
- jj-new(1) to insert a new commit after or before a specific other
commit.
Not all of these commands can be ported directly into Git. jj-new(1) for
example doesn't really make a ton of sense for us, I'd claim. But some
of these commands _do_ make sense.
I thus had a look at implementing some of these commands in Git itself,
where the result is this patch series. Specifically, the following
commands are introduced by this patch series:
- `git history drop` to drop a specific commit. This is basically the
same as jj-abandon(1).
- `git history reorder` to reorder a specific commit before or after
another commit. This is inspired by jj-new(1).
- `git history split` takes a commit and splits it into two. This is
basically the same as jj-split(1).
If this is something we want to have I think it'd be just a starting
point. There's other commands that I think are quite common and that
might make sense to introduce eventually:
- An equivalent to jj-absorb(1) would be awesome to have.
- `git history reword` to change only the commit message of a specific
commit.
- `git history squash` to squash together multiple commits into one.
In the end, I'd like us to learn from what people like about Jujutsu and
apply those learnings to Git. We won't be able to apply all learnings
from Jujutsu, as the workflow is quite different there due to the lack
of the index. But other things we certainly can apply to Git directly.
Note: This patch series currently builds on the cherry-pick infra.
As such, when one hits a merge conflict one needs to `git cherry-pick
--continue`, which is quite suboptimal. I didn't want to overpolish this
series before getting some feedback, but it is something I'll fix in
subsequent versions. Furthermore, the command for now bails out in the
case where there's any merge commits in the history that is being
rewritten. This is another restriction that can be lifted in the future.
Thanks!
Patrick
---
Patrick Steinhardt (11):
sequencer: optionally skip printing commit summary
sequencer: add option to rewind HEAD after picking commits
cache-tree: allow writing in-memory index as tree
builtin: add new "history" command
builtin/history: implement "drop" subcommand
builtin/history: implement "reorder" subcommand
add-patch: split out header from "add-interactive.h"
add-patch: split out `struct interactive_options`
add-patch: remove dependency on "add-interactive" subsystem
add-patch: add support for in-memory index patching
builtin/history: implement "split" subcommand
.gitignore | 1 +
Documentation/git-history.adoc | 159 ++++++++++
Documentation/meson.build | 1 +
Makefile | 1 +
add-interactive.c | 151 +++------
add-interactive.h | 43 +--
add-patch.c | 271 ++++++++++++++--
add-patch.h | 61 ++++
builtin.h | 1 +
builtin/add.c | 22 +-
builtin/checkout.c | 7 +-
builtin/commit.c | 16 +-
builtin/history.c | 691 +++++++++++++++++++++++++++++++++++++++++
builtin/reset.c | 16 +-
builtin/stash.c | 46 +--
cache-tree.c | 5 +-
cache-tree.h | 3 +-
commit.h | 2 +-
git.c | 1 +
meson.build | 1 +
sequencer.c | 36 ++-
sequencer.h | 4 +
t/meson.build | 5 +-
t/t3450-history-drop.sh | 127 ++++++++
t/t3451-history-reorder.sh | 218 +++++++++++++
t/t3452-history-split.sh | 304 ++++++++++++++++++
26 files changed, 1947 insertions(+), 246 deletions(-)
---
base-commit: c44beea485f0f2feaf460e2ac87fdd5608d63cf0
change-id: 20250819-b4-pks-history-builtin-83398f9a05f0
