Git Rebase multiple times on same topic branch

Question

I have a Topic branch which I continuous do development on it. From time to time I need to put the content back to Main Branch. I use rebase to do the merge for the first time ( T1 to B as shown in the picture). After that both Topic and Main branch continue to grow, at certain point T2 I want to rebase again

Problem comes here, what I want is to apply commits between T1 and T2 one by one to Main Head, however, git still tries to apply commits between T0 to T2 to Main head. In another word, git are not aware of the fact that commits between T0 and T1 has already been rebased to Main . This is causing many unnecessary conflicts.

I read through the git rebase documentation, but seems there is not a parameter which can specify the starting point to calculate the delta patches . So I am stuck at this point.

Any one can help me out?

Answer 1

You are mixing up merge and rebase .

You have merged T0.. T1 into the main branch, you have not rebased them onto the main branch. You should choose your strategy: rebase or merge always.

If you would have rebased T0..T1 on the main branch, your graph would have looked like this:

A main branch start
...
B <- main branch
T0'
...
T1' <- topic branch

That is: a linear history: Short recap:

• merge creates a single merge commit, history of each branch remains exactly as it was (as in your example)
• rebase rewrites the history of your (topic) branch. The result is a linear history.

Answer 2

Find the answer after reading rebase doc

git rebase --onto main T1 T2

It calculate the delta between [T1, T2] and apply them one by one to main .