Merge Branch Into Current

Scope

Use this skill inside a Git repository when the goal is to merge one branch into the current branch and keep an explicit merge commit.

Default behavior:

• Target branch: the current branch
• Source branch: the branch explicitly provided by the user
• Merge strategy: git merge --no-ff
• Dirty-check scope: the current worktree plus any active worktree that is currently checked out on the source or target branch

Do not use squash merge or rebase unless the user explicitly overrides the request.

Workflow

1. Resolve branch names

Collect:

• source branch, called "specified branch"
• target branch, called "current branch"

If the user gave both names, use them directly after verifying they exist.

If the user did not give names, inspect the repository:

git branch --show-current
git branch --format='%(refname:short)'

If the current branch is main, and there is exactly one local branch that satisfies all of the following, auto-select it as the source branch and continue without asking:

• it is not main
• it is not merged into main
• git rev-list --count main..BRANCH is at least 1

In that case:

• source branch = that unmerged branch
• target branch = main

If the auto-detection rule does not produce exactly one source branch, stop and ask the user for the source branch name. Target branch remains the current branch unless the user states otherwise.

2. Preflight checks

Verify the repository and branch state before merging:

git rev-parse --show-toplevel
git branch --show-current
git show-ref --verify --quiet refs/heads/<source-branch>
git show-ref --verify --quiet refs/heads/<target-branch>

The merge must run from a worktree currently checked out on the target branch. If the current worktree is not on the target branch, stop and tell the user to switch first.

3. Dirty-check both branches

Run the bundled script:

scripts/merge_branch_into_current.sh [source-branch] [target-branch]

The script must:

• inspect git worktree list --porcelain
• find any active worktree checked out on the source or target branch
• run git status --short inside each matching worktree
• abort if either branch has uncommitted tracked or untracked changes

If a matching branch has no active worktree, treat it as clean because Git cannot hold uncommitted state for that branch without a checked-out worktree.

When aborting, clearly report which branch and which worktree path is dirty, and tell the user to整理 or commit/stash those changes before retrying.

4. Merge

If both branches are clean, run:

git merge --no-ff <source-branch>

This preserves a merge commit even when fast-forward would be possible.

If merge conflicts occur:

• stop immediately
• report the conflicted files from git status --short
• do not auto-resolve unless the user asks

5. Report result

On success, report:

• source branch
• target branch
• resulting merge commit SHA from git rev-parse HEAD

Resources

scripts/

• merge_branch_into_current.sh: resolves branches when possible, checks worktree cleanliness for the source and target branches, and runs git merge --no-ff.