What does cherry-picking a commit with Git mean?

This quote is taken from: Version Control with Git

Using git cherry-pick The command git cherry-pick commit applies the changes introduced by the named commit on the current branch. It will introduce a new, distinct commit. Strictly speaking, using git cherry-pick doesn’t alter the existing history within a repository; instead, it adds to the history. As with other Git operations that introduce changes via the process of applying a diff, you may need to resolve conflicts to fully apply the changes from the given commit . The command git cherry-pick is typically used to introduce particular commits from one branch within a repository onto a different branch. A common use is to forward- or back-port commits from a maintenance branch to a development branch.

$ git checkout rel_2.3
$ git cherry-pick dev~2 # commit F, below

before:

after:

Also, here is a very nice in action video tutorial about it: Youtube: Introduction to Git cherry-pick

cherry-picking in Git is designed to apply some commit from one branch into another branch. It can be done if you, for example, made a mistake and committed a change into wrong branch, but do not want to merge the whole branch. You can just, for example, revert the commit and cherry-pick it on another branch.

To use it, you just need git cherry-pick hash, where hash is a commit hash from other branch.

For full procedure see: Git cherry-picking: Move small code patches across branches

I prepared step-by-step illustrations what cherry-pick does — and an animation of these illustrations (near the end).

1. Before cherry-picking
   (we are going to do a cherry-pick of the commit L from the branch feature):

2. Starting the command git cherry-pick feature~2
   (feature~2 is the 2^nd commit before
   feature, i.e. the commit L):

3. After performing the command (git cherry-pick feature~2):

The same animated:

Note:

The commit L' is from the user's point of view (commit = snapshot) the exact copy of the commit L.

Technically (internally), it's a new, different commit (because e.g. L contains a pointer to K (as its parent), while L' contains a pointer to E).

A short example of a situation when you need cherry-pick

Consider following scenario. You have two branches.

a) release1 - This branch is going to your customer, but there are still some bugs to be fixed.

b) master - Classic master branch, where you can for example add functionality for release2.

Now: You fix something in release1. Of course, you also need this fix in master. And that is a typical use-case for cherry-picking. So cherry-pick in this scenario means that you take a commit from release1 branch and include it into the master branch.

cherry-pick is a Git feature. If someone wants to Commit specific commits in one branch to a target branch, then cherry-pick is used.
git cherry-pick steps are as below.

1. checkout (switch to) target branch.

2. git cherry-pick <commit id>
   

   Here commit id is activity id of another branch.Eg.

   git cherry-pick 9772dd546a3609b06f84b680340fb84c5463264f
   

3. push to target branch

Visit https://git-scm.com/docs/git-cherry-pick

You can think if a cherry-pick as similar to a rebase, or rather it's managed like a rebase. By this, I mean that it takes an existing commit and regenerates it taking, as the starting point, the head of the branch you're currently on.

A rebase takes a commit that had a parent X and regenerates the commit as if it actually had a parent Y, and this is precisely what a cherry-pick does.

Cherry-pick is more about how you select the commits. With pull (rebase), Git implicitly regenerates your local commits on top of what's pulled to your branch, but with cherry-pick you explicitly choose some commit(s), and implicitly regenerate it (them) on top of your current branch.

So the way you do it differs, but under the hood they are very similar operations - the regeneration of commits.

It will apply a particular commit to your current branch.

This means:

• all files added by this commit will be added
• all files deleted by this commit will be deleted
• all files modified by this commit will be merged. This means the whole file from the commit, not only the changes from this commit!

Example: Consider commit A

added newFileA
modified main:
+ import './newFileA'

commit B

added newFileB
modified main:
+ import './newFileB'

If you cherry-pick commit B on another branch, Git will try to merge this:

/newFileB
/main :
   import './newFileA'
   import './newFileB'

... and most likely cause a merge conflict.
Since commit B contains newFileB and main but no newFileA, use with caution.

It's kind of like Copy (from somewhere) and Paste (to somewhere), but for specific commits.

If you want to do a hot fix, for example, then you can use the cherry-pick feature.

Do your cherry-pick in a development branch, and merge that commit to a release branch. Likewise, do a cherry-pick from a release branch to master. Voila

If you want to merge without commit ids you can use this command

git cherry-pick master~2 master~0

The above command will merge last three commits of master from 1 to 3

If you want to do this for single commit just remove last option

git cherry-pick master~2

This way you will merge 3rd commit from the end of master.

When you are working with a team of developers on a project, managing the changes between a number of Git branches can become a complex task. Sometimes you don't want to merge a whole branch into another, and only need to pick one or two specific commits. This process is called 'cherry-picking'.

I found a great article on cherry-picking. Check it out for in-depth details: Introduction to cherry-picking with Git

Here you can perform the cherry pick step by step

Pick only specific commit(s) and raise PR for only those changes:

Step 1: Select those commit hash (Click on commit id and get the complete hash):

https://bitbucket.org/project-name/repo-name/commits/52597fbcc7010e3d4e1ccbdeb5b325331bd3c26

In the above URL, commit hash is: 52597fbcc7010e3d4e1ccbdeb5b325331bd3c26

Step 2: Collect all commit hash that need to have in PR, Suppose, I need 3 commits and its code to have in master and I need raise the PR:

https://bitbucket.org/project-name/repo-name/commits/52597fbcc7010e3d4e1ccbdeb5b32

https://bitbucket.org/project-name/repo-name/commits/ed0e2169ca0f2c69687999977773cc100938185

https://bitbucket.org/project-name/repo-name/commits/5e770f730bacb9ee6e4804b5e66df90b6493139

Step 3: Go to the Repo and run following commands:

git stash
git checkout master
git pull origin master
git checkout -b "my-new-branch"
git cherry-pick 52597fbcc7010e3d4e1ccbdeb5b325331bd3c26
git cherry-pick ed0e2169ca0f2c69687999977773cc100938185
git cherry-pick 5e770f730bacb9ee6e4804b5e66df90b6493139

git push origin my-new-branch

Step 4: Raise the PR against master

Git commits to be picked by another branch and appended to the current working HEAD.

In layman's terms, you just take some particular commit (only a particular change, not the whole commit history) and merge it into some branch.

For example, the repository has three branches: one of them is the default - main, the second one is custom-branch1, and third is custom-branch2. You, for instance, need to pull some particular changes made in custom-branch2 into custom-branch1, so you do a cherry pick - switch to custom-branch1 and pull that particular commit.

Excerpt from the official documentation:

Given one or more existing commits, apply the change each one introduces, recording a new commit for each. This requires your working tree to be clean (no modifications from the HEAD commit).

When it is not obvious how to apply a change, the following happens:

1. The current branch and HEAD pointer stay at the last commit successfully made.

2. The CHERRY_PICK_HEAD ref is set to point at the commit that introduced the change that is difficult to apply.

3. Paths in which the change applied cleanly are updated both in the index file and in your working tree.

4. For conflicting paths, the index file records up to three versions, as described in the "TRUE MERGE" section of git-merge. The working tree files will include a description of the conflict bracketed by the usual conflict markers <<<<<<< and >>>>>>>.

No other modifications are made.

Read more...

Follow these steps for copy commit from branchA to branchB.

• Checkout to branchA
• Pull latest
• Checkout to branchB
• git cherry-pick {commit-id-of-branchA}
• git push origin branchB