# Merge & Cherrypick

Repository.merge_base(oid1: Oid, oid2: Oid) → Oid

  Find as good common ancestors as possible for a merge. Returns None if there is no merge base between the commits

Repository.merge(id: ~_pygit2.Oid | str, favor=MergeFavor.NORMAL, flags=<MergeFlag.FIND_RENAMES: 1>, file_flags=<MergeFileFlag.DEFAULT: 0>)

  Merges the given id into HEAD.

  Merges the given commit(s) into HEAD, writing the results into the working directory. Any changes are staged for commit and any conflicts are written to the index. Callers should inspect the repository’s index after this completes, resolve any conflicts and prepare a commit.

  Parameters:

  id

    The id to merge into HEAD

  favor

    An enums.MergeFavor constant specifying how to deal with file-level conflicts. For all but NORMAL, the index will not record a conflict.

  flags

    A combination of enums.MergeFlag constants.

  file_flags

    A combination of enums.MergeFileFlag constants.

Repository.merge_analysis(their_head: Oid, our_ref: str = 'HEAD') → tuple[MergeAnalysis, MergePreference]

  Analyzes the given branch and determines the opportunities for merging it into a reference (defaults to HEAD).

  Parameters:

  our_ref

    The reference name (String) to perform the analysis from

  their_head

    Head (commit Oid) to merge into

  The first returned value is a mixture of the MergeAnalysis.NONE, NORMAL, UP_TO_DATE, FASTFORWARD and UNBORN flags. The second value is the user’s preference from ‘merge.ff’

## The merge method

The method does a merge over the current working copy. It gets an Oid object as a parameter.

As its name says, it only does the merge, does not commit nor update the branch reference in the case of a fastforward.

Example:

    >>> from pygit2.enums import MergeFavor, MergeFlag
    >>> other_branch_tip = '5ebeeebb320790caf276b9fc8b24546d63316533'
    >>> repo.merge(other_branch_tip)
    >>> repo.merge(other_branch_tip, favor=MergeFavor.OURS)
    >>> repo.merge(other_branch_tip, flags=MergeFlag.FIND_RENAMES | MergeFlag.NO_RECURSIVE)
    >>> repo.merge(other_branch_tip, flags=0)  # turn off FIND_RENAMES (on by default if flags omitted)

You can now inspect the index file for conflicts and get back to the user to resolve if there are. Once there are no conflicts left, you can create a commit with these two parents.

    >>> user = repo.default_signature
    >>> tree = repo.index.write_tree()
    >>> message = "Merging branches"
    >>> new_commit = repo.create_commit('HEAD', user, user, message, tree,
                                        [repo.head.target, other_branch_tip])

## Cherrypick

Repository.cherrypick(id: Oid)

  Cherry-pick the given oid, producing changes in the index and working directory.

  Merges the given commit into HEAD as a cherrypick, writing the results into the working directory. Any changes are staged for commit and any conflicts are written to the index. Callers should inspect the repository’s index after this completes, resolve any conflicts and prepare a commit.

Note that after a successful cherrypick you have to run `Repository.state_cleanup()` in order to get the repository out of cherrypicking mode.

## Lower-level methods

These methods allow more direct control over how to perform the merging. They do not modify the working directory and return an in-memory Index representing the result of the merge.

Repository.merge_commits(ours: str | ~_pygit2.Oid | ~_pygit2.Commit, theirs: str | ~_pygit2.Oid | ~_pygit2.Commit, favor=MergeFavor.NORMAL, flags=<MergeFlag.FIND_RENAMES: 1>, file_flags=<MergeFileFlag.DEFAULT: 0>) → Index

  Merge two arbitrary commits.

  Returns: an index with the result of the merge.

  Parameters:

  ours

    The commit to take as “ours” or base.

  theirs

    The commit which will be merged into “ours”

  favor

    An enums.MergeFavor constant specifying how to deal with file-level conflicts. For all but NORMAL, the index will not record a conflict.

  flags

    A combination of enums.MergeFlag constants.

  file_flags

    A combination of enums.MergeFileFlag constants.

  Both “ours” and “theirs” can be any object which peels to a commit or the id (string or Oid) of an object which peels to a commit.

Repository.merge_trees(ancestor: str | ~_pygit2.Oid | ~_pygit2.Tree, ours: str | ~_pygit2.Oid | ~_pygit2.Tree, theirs: str | ~_pygit2.Oid | ~_pygit2.Tree, favor=MergeFavor.NORMAL, flags=<MergeFlag.FIND_RENAMES: 1>, file_flags=<MergeFileFlag.DEFAULT: 0>)

  Merge two trees.

  Returns: an Index that reflects the result of the merge.

  Parameters:

  ancestor

    The tree which is the common ancestor between ‘ours’ and ‘theirs’.

  ours

    The commit to take as “ours” or base.

  theirs

    The commit which will be merged into “ours”.

  favor

    An enums.MergeFavor constant specifying how to deal with file-level conflicts. For all but NORMAL, the index will not record a conflict.

  flags

    A combination of enums.MergeFlag constants.

  file_flags

    A combination of enums.MergeFileFlag constants.

## N-way merges

The following methods perform the calculation for a base to an n-way merge.

Repository.merge_base_many(oids: list[Oid]) → Oid

  Find as good common ancestors as possible for an n-way merge. Returns None if there is no merge base between the commits

Repository.merge_base_octopus(oids: list[Oid]) → Oid

  Find as good common ancestors as possible for an n-way octopus merge. Returns None if there is no merge base between the commits

With this base at hand one can do repeated invokations of `Repository.merge_commits()` and `Repository.merge_trees()` to perform the actual merge into one tree (and deal with conflicts along the way).