how-to-rebase-and-squash-many-commits-into-one.md

1 Create or checkout branch B1

git checkout -b B1
git checkout B1

2 Update origin/master

git fetch origin
git fetch upstream          ??
git pull upstream master    ??

3 Interactive rebase B1 onto origin/master and squash

git rebase -i origin/master    // to reduce my commits
git rebase -i upsteam/master   ?? to stay up to date

(not covered: git rebase -i HEAD~4

Edit to

pick 8888888 Commit message 1
squash 8888888 Commit message 2
squash 8888888 Commit message 3

4 push -f

You must push -f (after the first push) because you replace the remote head of your branch with your local, potentially overwriting a 3rd party head.

Links

https://medium.com/@dirk.avery/the-definitive-git-rebase-guide-dbd7717f9437