Git branching from an older revision and rolling back the current branch

Question

I don't know Git all that well and for one of our repositories, I made a mistake.

I committed and pushed changes to a branch named "core". But then I realised that my changes should not be there - I should've created a new branch several revisions ago, say, "core-experimental".

To explain, I have:

A---B---C---D---E     "core"

But now I want to change it to

A---B              "core"
    \
     C---D---E     "core-experimental"

No one else in my team has pulled my changes yet, so any reverts I do shouldn't cause pain to anyone.

Is this possible for Git?

Answer 1

The other two answers work fine, but you can actually avoid having to do anything in your work tree:

# create core-experimental using core as starting point
git branch core-experimental core
# move core
git branch -f core <SHA1 of B>

This way you can do it even if you have local modifications in the work tree, and without updating a bunch of timestamps during checkout/resets which will cause you to have to rebuild (assuming this is a compiled project).

Answer 2

git checkout core
git branch core-experimental
git reset --hard <SHA of B>
git push -f <remote> core

Or more descriptively...

1. Checkout core
2. Create the experimental branch at core's HEAD
3. Reset core's HEAD back to where you want it
4. Force a push of the update core

Answer 3

In core:

git branch core-experimental
git reset --hard <revision-B>

And then:

git push -f