Move branch pointer to different commit without checkout

To move the branch pointer of a checked out branch, one can use the git reset --hard command. But how to move the branch pointer of a not-checked out branch to point at a different commit (keeping all other stuff like tracked remote branch)?

Solution 1:

git branch -f <branch-name> [<new-tip-commit>]

If new-tip-commit is omitted it defaults to the current commit.

Solution 2:

You can do it for arbitrary refs. This is how to move a branch pointer:

git update-ref -m "reset: Reset <branch> to <new commit>" refs/heads/<branch> <commit>

where -m adds a message to the reflog for the branch.

The general form is

git update-ref -m "reset: Reset <branch> to <new commit>" <ref> <commit>

You can pick nits about the reflog message if you like - I believe the branch -f one is different from the reset --hard one, and this isn't exactly either of them.

Solution 3:

You can also pass git reset --hard a commit reference.

For example:

git checkout branch-name
git reset --hard new-tip-commit

I find I do something like this semi-frequently:

Assuming this history

$ git log --decorate --oneline --graph
* 3daed46 (HEAD, master) New thing I shouldn't have committed to master
* a0d9687 This is the commit that I actually want to be master

# Backup my latest commit to a wip branch
$ git branch wip_doing_stuff

# Ditch that commit on this branch
$ git reset --hard HEAD^

# Now my changes are in a new branch
$ git log --decorate --oneline --graph
* 3daed46 (wip_doing_stuff) New thing I shouldn't have committed to master
* a0d9687 (HEAD, master) This is the commit that I actually want to be master