如何在非连续提交之间移动更改？

Question

So, the situation is like this:

Commit A
**Commit B**
Commit C
Commit D
**Commit E**

Is it possible to pick one file-change from Commit E and move it to Commit B ? Commits C and D don't have anything related to that specific file so I am hoping this is doable.

Answer 1

You can checkout the file as it is in COMMIT-E
Note that this will undo any changes you did to the file in your current branch. You can however edit out the unwanted changes to that file easily because they will be in your commit diff.

# checkout COMMIT-B, ether check out the commit directly ( headless mode ), or checkout the relevan branch.
git checkout COMMIT-B 
git checkout COMMIT-E ./dir/myfile.ext

The file is now in your working directory, you can commit it individually or as part of an other commit. If you checked out COMMIT-B directly ( without a branch ) make sure you create a branch before you navigate away.

Note that if you don't specify the path for the checkout command, your HEAD will change, which you don't want.

If you made any changes to the specific file in your current branch, and you want to preserve those without having to edit the file ( as mentioned above ), you will need to cherry pick the change in commit-E.

# checkout COMMIT-B, ether check out the commit directly ( headless mode ), or checkout the relevan branch.
git checkout COMMIT-B 
git cherry-pick -n COMMIT-E
# clean up the changes you don't want, then commit the changes you are interested in.

If there are multiple changes to the file in the other branch, spread out over multiple commits, it might be tricky to cherry pick all those changes. You could try to rebase the branch on top of your current branch and then checkout the file again as demonstrated above. Or you could create a temporary branch at your current branch, merge the other branch in your temporary branch, checkout COMMIT-B, checkout the file from the temporary branch, commit the file ( clean up by deleting the temporary branch and reset the merged-in branch back to where it came from )
All tough rebasing is probably a more straightforward option, the end result should be similar for the targeted file.

Answer 2

Try with git-rebase :

git rebase -i commitA~1

This will open your default editor to choose what commit from commitA you want to redo.

You will see something like this:

pick SHA1 commitA
pick SHA1 commitB
pick SHA1 commitC
pick SHA1 commitD
pick SHA1 commitE

Change it as you wish. In your case:

pick SHA1 commitA
pick SHA1 commitE
pick SHA1 commitC
pick SHA1 commitD
pick SHA1 commitB

This will generate a new history of commit with different SHA1 but with the same changes in the new order. Depending on the order, or if you remove some commits, you can have conflicts. Be careful.