Change a commit's parent

Occasionally I want to move some commits from one branch to another. I do this rarely enough that I forget how to do it each time, but often enough that I know I’ll need to do it again.

There are some detailed Stack Overflow answers that dig into different ways to do it. But I find them tricky to understand and follow, mainly because I know this is something I’ve done in the past without much fuss.

Here it is:

git rebase --onto <new-parent-ref> <old-parent-ref> <target-branch-ref>

If you skip the third argument, the current HEAD is used instead.

There are some great examples in the git docs.

Here’s an example from the docs that covers my most common use-case. With branches like:

 o---o---o---o---o  main
         \
          o---o---o---o---o  next
                           \
                            o---o---o  topic

And a desired layout of:

o---o---o---o---o  main
        |            \
        |             o--o--o  topic
         \
          o---o---o---o---o  next

You can use the following command:

git rebase --onto main next topic

Note that the refs can be commit hashes as well as branch names (does this apply to <target-branch-ref>?).

Thanks git!