Handling Merge Conflicts

What is a Merge Conflict?

A merge conflict happens when Git cannot automatically combine changes from two branches.
This usually occurs when two branches have changed the same part of a file, or when one branch deletes a file that the other branch has modified.

Why Do Conflicts Happen?

• Two people (or two branches) edit the same line in a file differently.
• One branch deletes a file that the other branch edits.
• Changes are made to the same section of a file in both branches.

Git tries to merge changes automatically, but if it’s unsure which change to keep, it stops and asks you to decide.

How Do You Know There’s a Conflict?

• When you run git merge (or git rebase), Git will pause and show a message like:

  Auto-merging file.txt
  CONFLICT (content): Merge conflict in file.txt
  Automatic merge failed; fix conflicts and then commit the result.
  

• git status will show files with conflicts as “Unmerged paths”.

What Does a Conflict Look Like?

Git marks the conflicting area in your file like this:

<<<<<<< HEAD
This is your change from the current branch.
=======
This is the change from the branch you are merging in.
>>>>>>> feature-branch

• Everything between <<<<<<< HEAD and ======= is your branch’s version.
• Everything between ======= and >>>>>>> branch-name is the other branch’s version.

How to Resolve a Conflict

1. Open the conflicted file(s).
2. Look for the conflict markers (<<<<<<<, =======, >>>>>>>).
3. Decide what the final content should be.
   • Keep your changes, the other branch’s changes, or combine them.
4. Remove the conflict markers and edit the file so it looks exactly how you want.
5. Mark the conflict as resolved by adding the file:

   git add <filename>
   

6. Complete the merge by committing:

   git commit
   

   • If you were in the middle of a merge, Git may auto-generate a commit message.

Example: Resolving a Conflict

Suppose both branches changed the same line in hello.txt:

After merging, hello.txt looks like:

Hello world!
<<<<<<< HEAD
This is my change.
=======
This is their change.
>>>>>>> feature-branch
Goodbye!

To resolve:

• Decide which line (or both) you want to keep.
• Edit the file, for example:

  Hello world!
  This is my change and their change.
  Goodbye!
  

• Save the file.
• Run:

  git add hello.txt
  git commit
  

Tips for Avoiding and Handling Conflicts

• Pull often to keep your branch up to date.
• Communicate with your team about what files you’re working on.
• Keep commits small and focused to make conflicts easier to resolve.
• Use tools like VS Code, GitKraken, or SourceTree for visual conflict resolution.

Tip:
You can always see which files have conflicts with git status.
Use git log --merge to see commits that are causing the