adding commits to earlier branches?

[alan-nf]

Firstly, thanks for making this great project.

Now my question: I have a repo that looks like this:

➜  git:(feature4) git sl
◇ 70bcbf7a 1h (main, remote origin/main) Initial commit
┃
◯ 2d27ec27 45m (feature1) feature1 work
┃
◯ bff4f430 45m (feature2) feature2 work
┃
◯ 5cd580b9 2m (feature3) feature3 work
┃
● e106b908 2m (feature4) feature4 work

My goal is to make another commit to the feature2 branch and end up with a repo that looks like this:

➜ git:(feature4) git sl
◇ 70bcbf7a 1h (main, remote origin/main) Initial commit
┃
◯ 2d27ec27 48m (feature1) feature1 work
┃
◯ bff4f430 48m feature2 work
┃
◯ 5e3fa576 1m (feature2) more feature2 work     # <=== new commit
┃
◯ 38dadd89 1m (feature3) feature3 work
┃
● 647556fd 1m (feature4) feature4 work

If I didn't use branches this would be trivial. I could just make a fixup commit, or a full commit and then git rebase -i. But I'm having trouble figuring out what the git branchless workflow should be if I'm using branches. This works but is a LOT of steps:

# Make the new commit
echo "more stuff" >> feature2.txt
git commit -a -m "more feature2 work"

# New repo state
➜  git:(feature4) git sl
◇ 70bcbf7a 1h (main, remote origin/main) Initial commit
┃
◯ 2d27ec27 46m (feature1) feature1 work
┃
◯ bff4f430 46m (feature2) feature2 work
┃
◯ 5cd580b9 2m (feature3) feature3 work
┃
◯ e106b908 2m feature4 work
┃
● 86e14ef3 1s (feature4) more feature2 work     # <=== new commit (wrong branch, wrong location)

# Move the new commit up using git rebase
➜  git:(feature4) git rebase -i HEAD~5
➜  git:(feature4) git restack

# New repo state
➜ git:(feature4) git sl
◇ 70bcbf7a 1h (main, remote origin/main) Initial commit
┃
◯ 2d27ec27 1h (feature1) feature1 work
┃
◯ bff4f430 1h (feature2) feature2 work
┃
◯ a841d4e9 4s more feature2 work     # <=== new commit (wrong branch, correct location)
┃
◯ 641cf3fa 3s (feature3) feature3 work
┃
● 8d6f9597 3s (feature4) feature4 work

# fix the branch pointer
➜  git:(feature4) git branch --force feature2 a841d4e9

# New repo state
➜  git:(feature4) git sl
◇ 70bcbf7a 1h (main, remote origin/main) Initial commit
┃
◯ 2d27ec27 1h (feature1) feature1 work
┃
◯ bff4f430 1h feature2 work
┃
◯ a841d4e9 1m (feature2) more feature2 work     # <=== new commit (correct branch, correct location)
┃
◯ 641cf3fa 1m (feature3) feature3 work
┃
● 8d6f9597 1m (feature4) feature4 work

Any tips on better ways of handling this?

[alan-nf]

NOTE: I tried a different way of doing this (make the new commit during an interactive rebase) but that method is equally verbose and also broken (#316)

[arxanas]

EDIT: for the time being, I've added a workflow documentation item titled "Adding a commit to an earlier branch" which points to this answer.

As a general resource, you might want to read this article, as it may answer some workflow questions: https://github.com/arxanas/git-branchless/wiki/Workflow:-Editing-an-old-commit's-contents. I've added a to-do to #115 for your specific use-case, and hopefully I'll get around to it someday 😅 .

For this case, here's what I would do:

1. git co feature-2
2. git commit -am 'more feature2 work'.

• EDIT: @sebastianst points out that in recent versions of git-branchless, rather than run git commit, you can instead run git record -Im 'more feature2 work' to insert the commit and skip step 3.

Your smartlog should look like this:

◇ 70bcbf7a 1h (main, remote origin/main) Initial commit
┃
◯ 2d27ec27 45m (feature1) feature1 work
┃
◯ bff4f430 45m feature2 work
┣━┓
┃ ◯ 5cd580b9 2m (feature3) feature3 work
┃ ┃
┃ ◯ e106b908 2m (feature4) feature4 work
┃
● 5cd580b9 2m (feature2) more feature2 work

3. git move -s feature-3 (which means "move the commits starting at feature3 on top of this commit"; see the documentation)

Now it should look like this:

◇ 70bcbf7a 1h (main, remote origin/main) Initial commit
┃
◯ 2d27ec27 45m (feature1) feature1 work
┃
◯ bff4f430 45m feature2 work
┃
● 5cd580b9 2m (feature2) more feature2 work
┃
◯ 5cd580b9 2m (feature3) feature3 work
┃
◯ e106b908 2m (feature4) feature4 work

Generally speaking, you don't need to heavily rely on git rebase -i to edit previous commits. You can instead just check out the given commit and start making your changes there. Commands like git move, git amend, and git restack will try to be helpful about restacking descendant branches.

[sebastianst]

Couldn't you also just use git record --insert for this workflow?

[alan-nf]

@sebastianst that would certainly let you take @arxanas three-command answer and turn it into two commands, yes. It didn't exist at the time of this discussion but it is helpful here.

[arxanas]

@sebastianst thanks for pointing out, I've updated the answer to mention git record --insert!

[pokey]

@arxanas you might want to delete that final parenthetical as well 😊

[arxanas]

@pokey yes, thanks!