Git合并仅更改来自特定提交的文件（而不是整个diff）

Question

So imagine an existing code base with files {A, B, C, D, E}. I clone the repo, create a branch, and issue a series of changes

Commit 1 changes files {A, B}
Commit 2 changes files {C, D}
Commit 3 changes files {D, E}

In this example, I need to merge to the parent the files that changed in commit 2, but without any of the changes in Commit 1.

It is my understanding that each commit contains snapshots of the entire code base, as illustrated here: source

So commit 2 has the changes to files C and D, but it also has the changes to file A and B from commit 1, which should not be merged.

So, how would I merge up the versions of C and D from Commit 2, without changing the parent's version of A and B?

Answer 1

One way would be to create a new branch out of your branch which has all 3 commits. Use git rebase to drop unwanted commits. Then checkout to parent branch and the use git merge new branch name

Answer 2

This is what git cherry-pick is for.

As I understand it, you want a new branch with only commit 2 on top of master , starting from this state:

o 8021  commit 3 that changes D and E  [feature-branch (HEAD)]
|
o bb6e  commit 2 that changes C and D
|
o f8a2  commit 1 that changes A and B
|
o 218a  commit 0 the initial state of the repository  [master]

First you should create a new branch just-commit-2 on top of master and check it out:

git checkout master
git checkout -b just-commit-2

Then cherry-pick commit 2:

git cherry-pick bb6e

You will end up with this state:

o 12c9  commit 2 that changes C and D  [just-commit-2 (HEAD)]
|
| o 8021  commit 3 that changes D and E  [feature-branch]
| |
| o bb6e  commit 2 that changes C and D
| |
| o f8a2  commit 1 that changes A and B
|/
o 218a  commit 0 the initial state of the repository  [master]

If you look at the state of your working tree at just-commit-2 , files C and D will be the only files different from the files in master .