Understanding Git Merge Conflicts and Repository Corruption

When merging branches in Git, conflicts occur if the same file has been modified in different branches. If conflicts are not resolved properly or history is rewritten incorrectly, the repository can become unstable, leading to orphaned commits, unmerged changes, or lost commits.

Common Causes of Merge Conflicts and Repository Corruption

  • Conflicting changes in the same file: Multiple branches modify the same file differently.
  • Rebasing onto a diverged history: Force-pushing after a rebase can break branch consistency.
  • Interrupted merge operations: Aborted merges leave the repository in an incomplete state.
  • Incorrect conflict resolution: Manually resolving conflicts improperly can cause missing changes.

Diagnosing Merge Issues

Checking for Ongoing Merge Conflicts

Identify unresolved conflicts:

git status

Look for files marked as both modified.

Listing Unmerged Files

Check which files have unresolved conflicts:

git ls-files -u

Inspecting Repository Integrity

Detect corrupted objects:

git fsck --full

Look for orphaned commits or missing objects.

Fixing Merge Conflicts and Repository Corruption

Resetting a Broken Merge

Abort an incomplete merge:

git merge --abort

Manually Resolving Merge Conflicts

Open each conflicted file and edit the conflict markers (<<<<<<<, =======, >>>>>>>).

git add resolved_file.txt
git commit

Recovering Lost Work After a Corrupt Merge

Find lost commits:

git reflog

Restore a previous commit:

git reset --hard HEAD@{1}

Reconstructing a Corrupt Repository

If the repository state is broken, reclone it:

git clone --mirror remote_repo.git

Preventing Future Merge Issues

  • Always fetch the latest changes before merging.
  • Use git mergetool for conflict resolution.
  • Avoid force-pushing after rebasing.

Conclusion

Git merge conflicts and repository corruption can disrupt workflows and lead to data loss. By properly resolving conflicts, monitoring repository health, and using safe merging practices, developers can maintain stable Git workflows.

FAQs

1. Why does Git say I have unresolved conflicts?

Git detected conflicting changes in the same file between branches.

2. How do I abort a merge if something goes wrong?

Use git merge --abort to cancel the merge.

3. Can I recover lost commits after a merge failure?

Yes, use git reflog to find and restore lost commits.

4. What should I do if my Git repository is corrupted?

Run git fsck to check integrity and reclone if necessary.

5. How do I prevent merge conflicts?

Regularly pull updates before merging and communicate changes with your team.