Git Merge: Combining Development Histories

Git merge is a command used in Git version control to integrate changes from one branch into another. It combines the development histories of branches, allowing developers to merge the changes made in one branch into another branch seamlessly.

One common scenario where `git merge` is useful is when working on feature branches. Suppose you have a feature branch `feature-branch` that contains new features or fixes. To integrate these changes into the main branch (e.g., `main` or `master`), you would execute the following command:

        git merge feature-branch
    

This command merges the changes from `feature-branch` into the current branch (often `main`). If there are no conflicts, Git will perform a “fast-forward” merge, updating the branch pointer to the latest commit of `feature-branch`.

Another use case is merging branches with conflicts. If both branches have changes in the same file or lines, Git will prompt for manual resolution of conflicts. After resolving conflicts, you can complete the merge with:

        git merge --continue
    

This command continues the merge process after conflicts are resolved and commits the merge.

To abort a merge in progress due to conflicts or other reasons, you can use:

        git merge --abort
    

This command cancels the merge operation and restores the branch to its state before `git merge` was started.

In cases where you want to merge changes from one remote branch into your current local branch, you can specify the remote and branch name:

        git merge origin/other-branch
    

Here, `origin/other-branch` is the remote branch you want to merge into your current local branch.

To verify if a merge was successful, you can inspect the commit history and branch pointers using:

        git log --oneline --graph
    

This command displays a concise log of commits, showing the merged branches and their respective commit histories.

Finally, to ensure that all changes are correctly reflected in the working directory after a merge, you can review the current status of files with:

        git status
    

This command shows the current state of the repository, highlighting any uncommitted changes or conflicts that may require attention.