I am pretty new to git, so I apologize if this is a simple solution.
I need to rebase the entire master branch of a repo to a feature branch. The repo was made, then someone used master as the first feature branch. So, what I have now is:
A -- B -- C -- D (branch: master)
and what I would like to do is
A--B--C--D (branch: new-feature)
/
Z (branch: master)
where Z represents a commit containing just a .gitignore file (or some other "repo-initializing commit" ... I'd even take a blank commit containing no files, but I don't think git likes/allows that).
I understand how to rebase commits within a branch, so I understand how to do this:
C--D (branch: new-feature)
/
A--B (branch: master)
but I have not been able to figure out how to rebase all of master onto a feature branch. I believe the crux of the issue I keep facing is that I don't have any commit to point master at, since there is no Z commit (commit A has partial feature implementation, so I can't use A in place of Z).
Thank you in advance!
Why bother rebasing? Just merge the new master base at the new feature tip. With master checked out (to provide a decent starting point)
git checkout -B feature
git branch -f master $(git commit-tree -m 'Initial commit.' `:|git mktree`)
git merge -s ours --allow-unrelated-histories master
producing
A ... D---E feature
/
Z master
and now history reflects exactly what happened, everything works.
If you really want to do the rebase, as the doc points out there's a --root option:
git checkout -B feature
git branch -f master $(git commit-tree -m 'Initial commit.' `:|git mktree`)
git rebase --root --onto master
which will cause heartache if any branches off of the old master (the new feature) exist anywhere.