git commit doesn't add to current branch

[bcspragu]

I've got a setup that looks something like:

◇ 67d7ee3 7h (main, remote origin/main) [...]
┃
◯ 0ccfe18 6h Commit #1
┃
◯ e5e6e68 2h Commit #2
┃
◯ 72a4e46 2h Commit #3
┃
◯ 60a10d8 1h (brandon/first-branch) Commit #4, out for review in PR1
┃
● 981808f 22m (brandon/second-branch) Commit #5, still working on it
┃
◯ 30e9a32 4m Commit #6, which I thought would get updated as brandon/second-branch, but didn't

I don't think I did anything special here, just:

git co # select brandon/second-branch
vim ... # write some code
git commit # commit the new stuff, 'Commit #6' in this example

I'd expect the branch pointer for brandon/second-branch to be on Commit #6, which is what usually happens, but it looks like I'm in a detatched HEAD state now?

My questions:

1. How did I end up here?
2. How do I fix it (e.g. move the branch pointer from 981808f to 30e9a32) without breaking everything?

[bcspragu]

I was able to fix it with git branch -f brandon/second-branch 30e9a32, but still not sure how I got into that state.

As a test, I checkout out brandon/second-branch and then ran:

git co -b brandon/second-branch-2
vim ... # write some code
git commit

And it worked as expected, brandon/second-branch-2 was updated to point to the latest commit

[claytonrcarter]

Hi there. I'm not very familiar w/ the interactive mode of git co, but it looks like it leaves you in a detached HEAD by design. So even though you selected the commit w/ your intended branch name, it just checked out that commit, not the branch. You can also use git switch <branch> or git checkout <branch> to checkout a branch. Your example with git co -b brandon/second-branch-2 worked as expected because specifying -b will bypass the interactive mode and act just like git checkout -b <branch>.

There are several other options for moving branches around. One is to just delete it and recreate it: git branch -D <branch>; git branch <branch> <commit>. Another is move it manually: git branch -f <branch> <commit>. Note that the latter doesn't work if you have that branch checked out.

[bcspragu]

Ah, I guess that's the distinction, I usually specify the branch name directly, I just thought the interactive mode would be more convenient. Good to know, thanks!

[arxanas]

@bcspragu Also check out the thread at #402 for some ideas on how to manipulate the branch pointer. I added a link to that thread to the Wiki.

For git co, it usually does delegate to git checkout, but like @claytonrcarter mentioned, it doesn't check out branches when using the interactive mode. I think there's a good case to be made for git-branchless to automatically check out the associated branch when moving to a given commit, whether by git co or by using git next/git prev. If you're interested in implementing that, I'm happy to guide you 🙂.

[bcspragu]

I'm definitely interested in trying to implement that, any pointers would be supremely useful

[bcspragu]

Sent out #526 as a first attempt, let me know what you think