git-rebase分支，建立在另一个分支之上，在master上

Question

I am working on a feature in a repo. I have created a feature branch (say branch_1 ) and another branch (say branch_2 ) on top of branch_1 . I used to rebase branch_2 every time branch_1 was updated, but now the branch_1 is being merged into master so I want to rebase branch_2 into master , so that branch_2 have only its own changes. How do I do this? Also is the right way or is there any other method?

Answer 1

You can just rebase this branch on master:

src/myproject (branch2)$ git rebase master

Any changes in contains that are already in master will be "swallowed" into those master changes, and you'll remain with just the distinct changes this branch contains.

Answer 2

It's quite convenient to never rebase your feature branches but merge them with the upstream. However, it kind of assumes that you don't deliver your merges but only the squashed content of the branches (because who wants all those merges on master, right?).

In large systems it can be quite nice to have this uplift history preserved in your development branch, since the uplift can introduce new problems to your feature. Rebasing the feature branch can hide what introduced the problem, even though the problem is of course the same.

Say you have branches master , feat1 off of master and feat2 off of feat1 .

To uplift feat2 to a new feat1 you do:

git fetch
git checkout origin/feat2
git merge origin/feat1
git push origin feat2

Uplifting feat1 to a new master would be:

git fetch
git checkout origin/feat1
git merge origin/master
git push origin feat1

But then say you want to switch upstream for feat2 because feat1 has been delivered to master . No problem.

git fetch
git checkout origin/feat2
git merge origin/master
git push origin feat2

Answer 3

There are several possible solutions for you request. If you are not satisfied with Mureinik's answer you can try to rebuild your branch using git cherry-pick . Basically, create a new branch from master and pick all commits from the place where branch_1 was merged into master to HEAD commit of branch_2 . To do so you will have to use a command like (assuming you are on the new branch):

git cherry-pick branch_2~10 branch_2

assuming that 10 is the number of commits in branch_2 after merging of branch_1 . branch_2 without specifying a number of 'commits back' is the latest commit of the branch.