GIT: Using git-cherry-pick

Recently I ran into a problem on a project where I was working on the wrong branch and committed changes. Those commits were supposed to go elsewhere and I now I need to get them into the correct branch!

There are a few options to solve this:

• Merge the incorrect branch into the correct branch. But I don’t want to that because there are items in the incorrect branch that I don’t want. So, that’s out.
• Recreate those changes in my working branch and just go on with my day. But that’s a waste of my time and I’m adamantly against redoing work!
• Create a patch and then apply that patch to the new branch.

All solid options but there’s still something better:

$ git cherry-pick

Let’s review where we’re at and then how to solve the problem using git-cherry-pick.

The State of Things

I created a new commit in my repository, in the branch called some_other_feature. But that’s the wrong branch!

$ git branch
    develop
    master
    my_new_feature
*   some_other_feature
    stage

The new commit should be on the my_new_feature branch. I could merge the branches but the some_other_feature branch contains commits and changes that I don’t want in the other branch (they are not ready for merging into any upstream branches, like develop or master.

Here’s the commit I need to get into my_new_feature:

commit ec485b624e85b2cad930cf8b7c383a134748b057
Author: Ryan Irelan 
Date:   Fri Aug 19 10:44:47 2016 -0500

    new contact page

Using git-cherry-pick

The syntax of git-cherry-pick is this:

$ git cherry-pick [commit hash]

The first step is fetch the commit hash for the commits we want to cherry-pick. We can do that using git-log and then copying the hash (in full or just the last 7 characters will work) to our clipboard.

Next, we need to be on the branch where we want the changes to be (our destination branch).

$ git checkout my_new_feature

Now we can run the git-cherry-pick command and apply the commit to our destination branch.

$ git cherry-pick ec485b624e85b2cad930cf8b7c383a134748b057

This will return something like this:

[my_new_feature 1bf8955] new contact page
Date: Fri Aug 19 10:44:47 2016 -0500
1 file changed, 1 insertion(+)
create mode 100644 contact.html

If we look at our log for this branch, we now see our commit:

$ git log
commit 1bf8955d5e6ca71633cc57971379e86b9de41916
Author: Ryan Irelan 
Date:   Fri Aug 19 10:44:47 2016 -0500

    new contact page

What’s happening when we run git-cherry-pick?

• Git is fetching the changes in the specified commit and replaying them in the current branch. The commits are not removed from the source branch; they remain intact.
• Because this commit is being applied to a new branch and therefore has different contents it will get a different hash than the source commit.

With the problem solved, we are ready to move on with our development work!

GIT: Using the Git cherry-pick command

38.1. Applying a single commit with cherry-pick

The git cherry-pick command allows you to select the patch which was introduced with an individual commit and apply this patch on another branch. The patch is captured as a new commit on the other branch.

This way you can select individual changes from one branch and transfer them to another branch.

The new commit does not point back to its original commit so do not use  cherry-pick blindly since you may end up with several copies of the same  change. Most often cherry-pick is either used locally (to emulate an interactive  rebase) or to port individual bug fixes done on a development branch into  maintenance branches.

38.2. Example: Using cherry-pick

In the following example you create a new branch and commit two changes.

# create new branch
git checkout -b picktest

# create some data and commit
touch pickfile.txt
git add pickfile.txt
git commit -m "adds new file"

# create second commit
echo "changes to file" > pickfile.txt
git commit -a -m "changes in file"

You can check the commit history, for example, with the git log --oneline command.

# see change commit history

git log --oneline

# results in the following output

2fc2e55 changes in file
ebb46b7 adds new file
[MORE COMMITS]
330b6a3 initial commit

The following command selects the first commit based on the commit ID and applies its changes to the master branch. This creates a new commit on the master branch.

git checkout master
git cherry-pick ebb46b7

The cherry-pick command can be used to change the order of commits. git cherry-pick also accepts commit ranges for example in the following command.

git checkout master
# pick the last two commits
git cherry-pick picktest~1..picktest~2

If things go wrong or you change your mind, you can always reset to the previous state using the following command.

git cherry-pick --abort