[git] How to git-cherry-pick only changes to certain files?

If I want to merge into a Git branch the changes made only to some of the files changed in a particular commit which includes changes to multiple files, how can this be achieved?

Suppose the Git commit called stuff has changes to files A, B, C, and D but I want to merge only stuff's changes to files A and B. It sounds like a job for git cherry-pick but cherry-pick only knows how to merge entire commits, not a subset of the files.

The situation:

You are on your branch, let's say master and you have your commit on any other branch. You have to pick only one file from that particular commit.

The approach:

Step 1: Checkout on the required branch.

git checkout master

Step 2: Make sure you have copied the required commit hash.

git checkout commit_hash path\to\file

Step 3: You now have the changes of the required file on your desired branch. You just need to add and commit them.

git add path\to\file
git commit -m "Your commit message"

The other methods didn't work for me since the commit had a lot of changes and conflicts to a lot of other files. What I came up with was simply

git show SHA -- file1.txt file2.txt | git apply -

It doesn't actually add the files or do a commit for you so you may need to follow it up with

git add file1.txt file2.txt
git commit -c SHA

Or if you want to skip the add you can use the --cached argument to git apply

git show SHA -- file1.txt file2.txt | git apply --cached -

You can also do the same thing for entire directories

git show SHA -- dir1 dir2 | git apply -

Perhaps the advantage of this method over Jefromi's answer is that you don't have to remember which behaviour of git reset is the right one :)

 # Create a branch to throw away, on which we'll do the cherry-pick:
 git checkout -b to-discard

 # Do the cherry-pick:
 git cherry-pick stuff

 # Switch back to the branch you were previously on:
 git checkout -

 # Update the working tree and the index with the versions of A and B
 # from the to-discard branch:
 git checkout to-discard -- A B

 # Commit those changes:
 git commit -m "Cherry-picked changes to A and B from [stuff]"

 # Delete the temporary branch:
 git branch -D to-discard

I usually use the -p flag with a git checkout from the other branch which I find easier and more granular than most other methods I have come across.

In principle:

git checkout <other_branch_name> <files/to/grab in/list/separated/by/spaces> -p

example:

git checkout mybranch config/important.yml app/models/important.rb -p

You then get a dialog asking you which changes you want in "blobs" this pretty much works out to every chunk of continuous code change which you can then signal y (Yes) n (No) etc for each chunk of code.

The -p or patch option works for a variety of commands in git including git stash save -p which allows you to choose what you want to stash from your current work

I sometimes use this technique when I have done a lot of work and would like to separate it out and commit in more topic based commits using git add -p and choosing what I want for each commit :)

For the sake of completness, what works best for me is:

git show YOURHASH --no-color -- file1.txt file2.txt dir3 dir4 | git apply -3 --index -

It does exactly what OP wants. It does conflict resolution when needed, similarly how merge does it. It does add but not commit your new changes, see with status.

I found another way which prevents any conflicting merge on cherry-picking which IMO is kind of easy to remember and understand. Since you are actually not cherry-picking a commit, but part of it, you need to split it first and then create a commit which will suit your needs and cherry-pick it.

First create a branch from the commit you want to split and checkout it:

$ git checkout COMMIT-TO-SPLIT-SHA -b temp

Then revert previous commit:

$ git reset HEAD~1

Then add the files/changes you want to cherry-pick:

$ git add FILE

and commit it:

$ git commit -m "pick me"

note the commit hash, let's call it PICK-SHA and go back to your main branch, master for example forcing the checkout:

$ git checkout -f master

and cherry-pick the commit:

$ git cherry-pick PICK-SHA

now you can delete the temp branch:

$ git branch -d temp -f

Use git merge --squash branch_name this will get all changes from the other branch and will prepare a commit for you. Now remove all unneeded changes and leave the one you want. And git will not know that there was a merge.

Cherry pick is to pick changes from a specific "commit". The simplest solution is to pick all changes of certain files is to use

 git checkout source_branch <paths>...

In example:

$ git branch
* master
  twitter_integration
$ git checkout twitter_integration app/models/avatar.rb db/migrate/20090223104419_create_avatars.rb test/unit/models/avatar_test.rb test/functional/models/avatar_test.rb
$ git status
# On branch master
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#
#   new file:   app/models/avatar.rb
#   new file:   db/migrate/20090223104419_create_avatars.rb
#   new file:   test/functional/models/avatar_test.rb
#   new file:   test/unit/models/avatar_test.rb
#
$ git commit -m "'Merge' avatar code from 'twitter_integration' branch"
[master]: created 4d3e37b: "'Merge' avatar code from 'twitter_integration' branch"
4 files changed, 72 insertions(+), 0 deletions(-)
create mode 100644 app/models/avatar.rb
create mode 100644 db/migrate/20090223104419_create_avatars.rb
create mode 100644 test/functional/models/avatar_test.rb
create mode 100644 test/unit/models/avatar_test.rb

Sources and full explanation http://jasonrudolph.com/blog/2009/02/25/git-tip-how-to-merge-specific-files-from-another-branch/

UPDATE:

With this method, git will not MERGE the file, it will just override any other change done on the destination branch. You will need to merge the changes manually:

$ git diff HEAD filename

You can use:

git diff <commit>^ <commit> -- <path> | git apply

The notation <commit>^ specifies the (first) parent of <commit>. Hence, this diff command picks the changes made to <path> in the commit <commit>.

Note that this won't commit anything yet (as git cherry-pick does). So if you want that, you'll have to do:

git add <path>
git commit

I would just cherry-pick everything, then do this:

git reset --soft HEAD^

Then I would revert the changes I don't want, then make a new commit.

Merge a branch into new one (squash) and remove the files not needed:

git checkout master
git checkout -b <branch>
git merge --squash <source-branch-with-many-commits>
git reset HEAD <not-needed-file-1>
git checkout -- <not-needed-file-1>
git reset HEAD <not-needed-file-2>
git checkout -- <not-needed-file-2>
git commit