Conflict Resolution

Git Conflict Resolution & Triage

Advanced Recovery Techniques

Handling Git conflicts is a crucial skill. This guide covers how to survive "Merge Hell" and use advanced Git features for history manipulation and debugging.

1. The 3-Way Merge Mechanism

When rebasing or merging, Git compares the current branch, the incoming branch, and their common ancestor (the merge base).

• Merge Conflict: Occurs when two branches modify the same line of the same file, or one deletes a file while the other modifies it.
• Resolution: Use <<< HEAD (current changes) and >>> incoming (incoming changes) markers to manually accept or combine lines.

2. Advanced: Git Rerere

Reuse Recorded Resolution (Rerere) is a hidden Git feature.

• Concept: When you resolve a conflict, Git remembers how you solved it. If the exact same conflict happens again (e.g., during a long rebase), Git resolves it automatically.
• Enable: git config --global rerere.enabled true

3. Advanced: Interactive Rebase & Bisect

• git rebase -i (Interactive): Allows you to squash, drop, edit, or reword previous commits. Crucial for cleaning up a messy feature branch before a PR.
• git bisect: Uses a binary search algorithm to find the exact commit that introduced a bug. You mark the current state as bad and a past state as good, and Git checks out commits in between for testing.

Rebase & Conflict Flow

%%{init: {"theme": "default", "flowchart": {"useMaxWidth": true}}}%%
flowchart TD
    subgraph Git_Rebase ["Rebase Operation"]
        A["git rebase main"]
        B["Apply Commit 1"]
        C["Apply Commit 2 (Conflict!)"]
    end
    
    subgraph Triage ["Conflict Resolution"]
        D["Open Editor (VSCode / Vim)"]
        E["Resolve <<< HEAD / >>> incoming"]
        F["git add ."]
        G["git rebase --continue"]
    end
    
    subgraph Rerere ["Rerere Cache"]
        H["Record Resolution Pattern"]
        I["Auto-apply in Future"]
    end
    
    A --> B
    B --> C
    C -->|"Pauses Execution"| D
    D --> E
    E --> F
    F --> G
    G -.->|"Save memory"| H
    H -.->|"Cache hit"| I