Forking and adding a feature from the branch on a fork: Git subtree

[ddkapan]

A QUICK FYI:
Git subtree to add features from one repo to another and preserve commit history, or

How to fork a repo and add a feature from a new feature branch on the fork:

1. Forked the repo COMB to COMBddkapan on personal GitHub & clone from GitHub to your favorite place for git projects (mine is called GitHub)

cd ~/GitHub
git clone https://github.com/ddkapan/COMB COMBddkapan

2. Change directory to the local copy of CAPLES (the source repo)

cd ~/GitHub/CAPLES

3. Then split out the feature as a branch with the feature name as a subtree

git subtree split -P point_counts -b point_counts

4. Change directory to the COMBddkapan & make a feature branch

cd ~/GitHub/COMBddkapan
git branch point_counts
git checkout point_counts

5. Add the subtree to COMBddkapan

git subtree add -P point_counts /Users/dkapan/GitHub/CAPLES point_counts --squash

Note --squash(ing) is recommended to compress the source repo history from the subtree (could have done this at first) similar to rebase.

6. Push to upstream branch.

git push --set-upstream origin point_counts

7. Then, got to GitHub & make a pull request to developers (us) of the original COMB repo.

• Verify that the merge-pull worked: first check online. Then pull updates locally and run the code.
• (Back-out by resetting if necessary: e.g. git reset --hard HEAD~1) #careful

8. Once verified, return to the original source repo (in this case the local copy of CAPLES)

cd ~/GitHub/CAPLES

9. and delete the split out branch that you never even pushed to the remote

git branch -D point_counts

10. check that all is ok in the original source repository (CAPLES) and the new updated destination public repo (COMB), for instance, run

git status
git log 
#etc...