How do I split up a large Git branch into lots of smaller branches?
I have imported from SVN into Git, now I have one big branch, like this:
- work on feature C
- work on feature B
- work on feature C
- work on feature C
- work on feature B
- work on feature A
I want separate feature branches, for A, B, C. I'm cherry picking commits to new branches but this doesn't remove them from the original branch so I have to manually track which ones I have pulled out.
There are around 800 commits to split up, and maybe 50 features/bugfixes.
It would be nice to have the ones I have pulled out reflected this way somehow in the git log, so I know which ones I have already done. Is this possible?
I can rebase the entire branch, skipping the commits I have pulled out, but I'm worried this will cause lots of conflicts. I don't want to resolve 500 conflicts every time I pull a commit out.
What's the best method of pulling out commits from one uber branch onto smaller feature branches, whilst keeping track of your progress?
Answer
What I do in this case is use interactive rebase.
At your HEAD, create your branches A, B, and C. Also create a "backup" branch (you could name it backup) in case things go wrong and you need your original HEAD back.
git branch feature-a
git branch feature-b
git branch feature-c
git-branch backup-before-rebase
Then, create a branch at the commit you want them to start from, maybe at a convenient stable commit. Call it new_trunk or something.
git checkout HEAD~50 ## this will be the new tree-trunk
git branch new_trunk
Then, do interactive rebases and pick out the commits you want to keep in that branch. Used this way, it's basically like cherry-picking in bulk.
git checkout feature-a
git rebase -i new_trunk ## -i is for "Interactive"
When you're done, you should have 3 branches with separate histories starting from new_trunk and a backup branch reflecting the old HEAD if you still need it.