Push a commit in two branches with Git

Question

how do I push a commit in two branches? I can't use "git push", because then it pushes to three branches, and i just want the commit in two of them.. Ive tried a "git merge HEAD --commit id from branch A--" in branch B, but then it takes everything from branch A and merges with branch B. I just want the last commit and not everything else merged with branch B. Anyone know what to do?

Accepted Answer

Short answer

You can apply already existing commit to another branch using `cherry-pick` command, and then push both branches using `git push origin branchA branchB`.

Why pushing a commit in two branches might be useful

Assume you have a repository with this structure:

```
A--B--C--D  ← master ← HEAD
      \--E  ← v1-release
```

After some development (commits `A`, `B`, `C`) project was released and `v1-release` branch was created (so that v1 can be supported with bugfixes and next version can be developed in `master`). Commit `E` was used to specify version information (added release notes, etc). Commit `D` introduced new feature, which is planned for the next version and should not appear in `v1-release`.

Now, if a bug is found in `v1-release`, it must be fixed in both branches, so that users can continue using v1 and it does not appear in the next version.

After fixing the bug in `master`, repository should look like this:

```
A--B--C--D--F  ← master ← HEAD
      \--E     ← v1-release
```

Now commit `F` with a bugfix must be applied to `v1-release` branch.

How to actually do it

Commits cannot be exactly copied (since commit is a directory saved state), but you can apply changes made in commit to another commit.

`cherry-pick` command does exactly that. It applies changes made by a specified commit to the current branch, creating new commit:

```
git checkout v1-release
git cherry-pick F
```

After this, repository should look like this:

```
A--B--C--D--F  ← master
      \--E--G  ← v1-release ← HEAD
```

Commit `G` introduces same changes as `F`.

You may have to resolve conflicts (exactly like after merge).

Error message

The previous cherry pick was now empty ...

means that changes made by cherry-picked commit are already present in current branch. You probably forgot to checkout correct branch.

In case of errors or conflicts cherry-pick can be aborted using `git cherry-pick --abort`.

Finally, you can return to `master` branch and push both branches to remote repository:

```
git checkout master
git push origin master v1-release
```

Final repository structure:

```
A--B--C--D--F  ← master ← HEAD
      \--E--G  ← v1-release
```

Push a commit in two branches with Git

Solution

Problem