Question

I have two branches. Say, the first one commit’s checksum is 11223344, the second one has 55667788. How to assign the commit 55667788 to the first branch?

Answer 1

If you simply want to apply the changes in commit 55667788 to branch first, you can just use cherry-pick.

git checkout first
git cherry-pick 55667788

If you are actually after importing all commits that second has that first doesn’t (including 55667788) you would merge it.

git checkout first
git merge --no-ff second

The --no-ff argument is made clear here

^{(From nvie.com, Vincent Driessen, post “A successful Git branching model“)}