merge conflicts

Introduction §

Merge conflicts in Git occur when two branches have made edits to the same part of a file and Git is unable to automatically resolve these changes. Understanding how to address these conflicts is essential for smooth collaboration and maintaining a clean project history.

Context §

Scenario 1: Merge §

When merging branches (e.g., merging featureA into main), conflicts may arise:

1. Switch to the main branch:

   git checkout main

2. Merge the feature branch:

   git merge featureA

Scenario 2: Rebase §

Conflicts can also occur during rebase operations:

1. Rebase a feature branch onto the main branch:

   git rebase main featureA

Conflict Example §

Conflicts are indicated in the file with markers:

<<<<<<<< HEAD
if x == 0:
  return false
========
if y == 6:
  return true
elif x == 0:
  return false
>>>>>>> d123456

Resolving the Conflict §

Manually §

1. Open the file in a text editor:

   vim conflict_file.txt

2. Resolve the conflict by choosing one of the options:
   • Option 1: Keep “OUR” change (current branch)
   • Option 2: Keep “THEIR” change (other branch)
   • Option 3: Write a new resolution

Using GUI §

1. Run git mergetool for a GUI-based conflict resolution tool like Meld.

Using vim’s Fugitive §

• Write how to resolve merge conflicts using Fugitive.

Using Lazygit §

• Write how to resolve merge conflicts using Lazygit.

Continuing After Resolution §

1. Stage the resolved files:

   git add <resolved-files>

2. Check for remaining conflicts:

   git diff --check

3. Continue the merge or rebase:
   • For merge:

     git merge --continue

   • For rebase:

     git rebase --continue

Additional Notes §

• The --ours and --theirs options can be used in both merge and rebase scenarios to choose changes from the current branch or the incoming branch, respectively.
• Always ensure conflicts are fully resolved and the code is functional before continuing with merges or rebases.

Understanding and resolving merge conflicts is a critical skill in Git, enabling smoother integration of changes from different branches.