Git Branch Merge

Change Platform:

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GitHub Bitbucket GitLab

Merge Branches

We have the emergency fix ready, and so let's merge the master and emergency-fix branches.

First, we need to change to the master branch:

git checkout master
Switched to branch 'master'

Now we merge the current branch (master) with emergency-fix:

git merge emergency-fix
Updating 09f4acd..dfa79db
Fast-forward
 index.html | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Since the emergency-fix branch came directly from master, and no other changes had been made to master while we were working, Git sees this as a continuation of master. So it can "Fast-forward", just pointing both master and emergency-fix to the same commit.

As master and emergency-fix are essentially the same now, we can delete emergency-fix, as it is no longer needed:

git branch -d emergency-fix
Deleted branch emergency-fix (was dfa79db).

Merge Conflict

Now we can move over to hello-world-images and keep working. Add another image file (img_hello_git.jpg) and change index.html, so it shows it:

git checkout hello-world-images
Switched to branch 'hello-world-images'

Now, we are done with our work here and can stage and commit for this branch:

git add --all
git commit -m "added new image"
[hello-world-images 1f1584e] added new image
 2 files changed, 1 insertion(+)
 create mode 100644 img_hello_git.jpg

Now we are ready to merge this hello-world-images into master. But what will happen to the changes we recently made in master?

We see that index.html has been changed in both branches. Now we are ready to merge hello-world-images into master. But what will happen to the changes we recently made in master?

git checkout master
git merge hello-world-images
Auto-merging index.html
CONFLICT (content): Merge conflict in index.html
Automatic merge failed; fix conflicts and then commit the result.

The merge failed, as there is conflict between the versions for index.html. Let us check the status:

git status
On branch master
You have unmerged paths.
  (fix conflicts and run "git commit")
  (use "git merge --abort" to abort the merge)

Changes to be committed:
        new file:   img_hello_git.jpg
        new file:   img_hello_world.jpg

Unmerged paths:
  (use "git add <file>..." to mark resolution)
        both modified:   index.html

This confirms there is a conflict in index.html, but the image files are ready and stagedto be committed.

So we need to fix that conflict. Open the file in our editor:

We can see the differences between the versions and edit it like we want:

Now we can stage index.html and check the status:

git add index.html
git status
On branch master
All conflicts fixed but you are still merging.
  (use "git commit" to conclude merge)

Changes to be committed:
        new file:   img_hello_git.jpg
        new file:   img_hello_world.jpg
        modified:   index.html

The conflict has been fixed, and we can use commit to conclude the merge:

git commit -m "merged with hello-world-images after fixing conflicts"
[master e0b6038] merged with hello-world-images after fixing conflicts

And delete the hello-world-images branch:

git branch -d hello-world-images
Deleted branch hello-world-images (was 1f1584e).

Now you have a better understanding of how branches and merging works. Time to start working with a remote repository!

git  hello-you