Fixing a commit in the middle of a set

Another tip for those who’ve needed to do this: let’s say you’ve created a feature branch and are adding tests to the code, and you realize that one of your tests is incorrect several commits further on. What do you do?

If this is a plain old feature branch, you can just make the fixup commit and have two commits for that test. This is perfectly fine.

If however, you’re constructing a series of commits to be cherry-picked later, it’s better to have all the related changes together.

You can do this by doing a git log and capturing the output in order back to the incomplete commit. Save that output, then git reset --hard oldcommit.

The incomplete commit is now the current one, so you can make any fixes you need, git add them, and then git commit --amend to include them in the current (formerly incomplete) commit.

Now go back to the log output, and find the commit just after the current one; record that, and then record the old HEAD commit. git cherry-pick nextcommit..oldhead will then reapply all of the commits following the one you just repaired, and your branch will be back where it was, with the one incorrect commit repaired.