git-merge

Join development histories together

TLDR

Merge branch into current

$ git merge [branch-name]

Merge with commit message

$ git merge [branch] -m "[message]"

Merge without fast-forward (preserve topology)

$ git merge --no-ff [branch]

Only allow fast-forward, otherwise fail

$ git merge --ff-only [branch]

Squash merge (single staged changeset, no merge commit)

$ git merge --squash [branch]

Favor our or their side on conflicts

$ git merge -X ours [branch]

Abort or continue an in-progress merge

$ git merge --abort``` / ```git merge --continue

SYNOPSIS

git merge [options] [commit...]git merge (--continue | --abort | --quit)

git merge incorporates changes from the named commits (typically branch tips) into the current branch. It is also invoked internally by git pull to integrate fetched changes.A fast-forward merge simply advances the current branch pointer to the merged commit without creating a new commit; `--no-ff` forces a merge commit to preserve branch topology, while `--ff-only` refuses the merge unless it is a fast-forward. Squash merges (`--squash`) collapse all incoming changes into a single staged changeset without recording a merge commit.When textual conflicts occur, conflict markers are written into affected files; resolve them, `git add` the files, then run `git merge --continue` (or `git commit`). The default strategy is ort ("Ostensibly Recursive's Twin"), which replaced the older recursive strategy in Git 2.33 and handles three-way merges with rename detection.

PARAMETERS

COMMIT

Branch or commit to merge into current branch.

--no-ff

Always create a merge commit, even when fast-forward is possible.

--ff-only

Refuse to merge unless the current HEAD can be fast-forwarded.

--squash

Produce working tree/index as if a real merge happened, but do not make a commit.

--no-commit

Perform the merge but stop before creating a commit (allows inspection).

-m MESSAGE

Set the commit message for the merge commit.

-e, --edit

Invoke the editor to refine the auto-generated commit message.

--abort

Abort the current conflict resolution and reconstruct the pre-merge state.

--continue

Continue the merge after conflicts have been resolved.

--quit

Forget about the current merge in progress without restoring the pre-merge state.

-s STRATEGY, --strategy=STRATEGY

Select merge strategy: `ort` (default), `resolve`, `octopus`, `ours`, or `subtree`.

-X OPTION, --strategy-option=OPTION

Pass a strategy-specific option (e.g., `ours`, `theirs`, `ignore-all-space`, `find-renames`).

--autostash

Automatically stash and restore local changes around the merge.

--allow-unrelated-histories

Merge histories that do not share a common ancestor.

--verify-signatures

Require a valid GPG signature on the side branch tip.

-S[KEYID], --gpg-sign[=KEYID]

GPG-sign the resulting merge commit.

--log[=N]

Include one-line descriptions of the merged commits in the merge commit message.

--help

Display help information.

CAVEATS

Conflicts require manual resolution before the merge can complete. Fast-forward merges discard branch topology unless `--no-ff` is used. Using `-X ours`/`-X theirs` silently discards one side's changes on conflict. The `--strategy=ours` option is very different from `-X ours` and keeps only the current branch's tree.

HISTORY

git merge has been a core Git command since its earliest releases. The default strategy was renamed from recursive to ort in Git 2.33 (August 2021) for correctness and performance improvements. `--autostash` was added in Git 2.27, and `--quit` in Git 2.11.