将多个分支合并为一个分支

Question

Assuming I have branches o1 o2 o3 o4 .

They all have multiple commits where all commits in o1 were made before o2 which were made before o3 , etc...

I want to create a branch d1 which contains all commits from o1 , o2 , o3 and o4 intact. Ie same hash identifier. You can assume that they do not conflict with each other.

The main purpose is that if they become merged to somewhere else in the project, no duplicate commits are detected (2 different commits with the same changes).

I'm puzzled trying to do this because git merge removes the branch after merging and it is the only thing I was able to think of and cherry-pick (if I understood right), doesn't seem to be a proper option.

Answer 1

The only way you can create d1 without modifying the hashes is if you already have history that looks something like this:

* -- * -- * -- * -- * -- * -- * -- * -- * -- * -- *
     o1             o2             o3             o4

That is, if everything you can reach from o1 is also reachable from o2 , etc. Otherwise, creating your branch d1 will involve creating at least one new commit from an old one, with the new one having a different parent. The parent of a commit contributes to its hash, so what you want is not possible.