GIT-HISTORY(1)

NAME
git-history - EXPERIMENTAL: Rewrite history

SYNOPSIS

git history fixup <commit> [--dry-run] [--update-refs=(branches|head)] [--reedit-message] [--empty=(drop|keep|abort)]
git history reword <commit> [--dry-run] [--update-refs=(branches|head)]
git history split <commit> [--dry-run] [--update-refs=(branches|head)] [--] [<pathspec>...]

DESCRIPTION

Rewrite history by rearranging or modifying specific commits in the history.

THIS COMMAND IS EXPERIMENTAL. THE BEHAVIOR MAY CHANGE.

This command is related to git-rebase(1) in that both commands can be used to rewrite history. There are a couple of major differences though:

    • Most subcommands of git-history(1) can work in a bare repository as they do not need to touch either the index or the worktree. The fixup subcommand is an exception to this, as it reads staged changes from the index.

    • git-history(1) does not execute any githooks(5) at the current point in time. This may change in the future.

    • git-history(1) by default updates all branches that are descendants of the original commit to point to the rewritten commit.

Overall, git-history(1) aims to provide a more opinionated way to modify your commit history that is simpler to use compared to git-rebase(1) in general.

Use git-rebase(1) if you want to reapply a range of commits onto a different base, or interactive rebases if you want to edit a range of commits at once.

LIMITATIONS

This command does not (yet) work with histories that contain merges. You should use git-rebase(1) with the --rebase-merges flag instead.

Furthermore, the command does not support operations that can result in merge conflicts. This limitation is by design as history rewrites are not intended to be stateful operations. The limitation can be lifted once (if) Git learns about first-class conflicts.

When using fixup with --empty=drop, dropping the root commit is not yet supported.

COMMANDS

The following commands are available to rewrite history in different ways:

fixup <commit>
    Apply the currently staged changes to the specified commit. This is similar in nature to git commit --fixup=<commit> followed by git rebase --autosquash <commit>~. Changes are applied to the target commit by performing a three-way merge between the HEAD commit, the target commit and the tree generated from staged changes.

    The commit message and authorship of the target commit are preserved by default, unless you specify --reedit-message.

    If applying the staged changes would result in a conflict, the command aborts with an error. All branches that are descendants of the original commit are updated to point to the rewritten history.

reword <commit>
    Rewrite the commit message of the specified commit. All the other details of this commit remain unchanged. This command will spawn an editor with the current message of that commit.

split <commit> [--] [<pathspec>...]
    Interactively split up <commit> into two commits by choosing hunks introduced by it that will be moved into the new split-out commit. These hunks will then be written into a new commit that becomes the parent of the previous commit. The original commit stays intact, except that its parent will be the newly split-out commit.

    The commit messages of the split-up commits will be asked for by launching the configured editor. Authorship of the commit will be the same as for the original commit.

    If passed, <pathspec> can be used to limit which changes shall be split out of the original commit. Files not matching any of the pathspecs will remain part of the original commit. For more details, see the pathspec entry in gitglossary(7).

    It is invalid to select either all or no hunks, as that would lead to one of the commits becoming empty.

OPTIONS

--dry-run
    Do not update any references, but instead print any ref updates in a format that can be consumed by git-update-ref(1). Necessary new objects will be written into the repository, so applying these printed ref updates is generally safe.

--reedit-message
    Open an editor to modify the target commit’s message.

--empty=(drop|keep|abort)
    Control what happens when a commit becomes empty as a result of the fixup. This can happen in two situations:

        • The fixup target itself becomes empty because the staged changes exactly cancel out all changes introduced by that commit.

        • A descendant commit becomes empty during replay because it introduced the same change that was just fixed up into an ancestor.

    With drop (the default), empty commits are removed from the rewritten history. Descendants of a dropped target commit are replayed directly onto the target’s parent. Note that dropping the root commit is not supported; see LIMITATIONS.

    With keep, empty commits are retained in the rewritten history as-is.

    With abort, the command stops with an error if any commit would become empty.

--update-refs=(branches|head)
    Control which references will be updated by the command, if any. With branches, all local branches that point to commits which are descendants of the original commit will be rewritten. With head, only the current HEAD reference will be rewritten. Defaults to branches.

EXAMPLES

  Fixup a commit

    $ git log --oneline --stat
    abc1234 (HEAD -> main) third
     third.txt | 1 +
    def5678 second
     second.txt | 1 +
    ghi9012 first
     first.txt | 1 +
    $ echo "change" >>unrelated.txt
    $ git add unrelated.txt
    $ git history fixup ghi9012
    $ git log --oneline --stat
    jkl3456 (HEAD -> main) third
     third.txt | 1 +
    mno7890 second
     second.txt | 1 +
    pqr1234 first
     first.txt     | 1 +
     unrelated.txt | 1 +

The staged addition of unrelated.txt has been incorporated into the first commit. All descendant commits have been replayed on top of the rewritten history.

  Split a commit

    $ git log --stat --oneline
    3f81232 (HEAD -> main) original
     bar | 1 +
     foo | 1 +
     2 files changed, 2 insertions(+)
    $ git history split HEAD
    diff --git a/bar b/bar
    new file mode 100644
    index 0000000..5716ca5
    --- /dev/null
    +++ b/bar
    @@ -0,0 +1 @@
    +bar
    (1/1) Stage addition [y,n,q,a,d,p,?]? y
    diff --git a/foo b/foo
    new file mode 100644
    index 0000000..257cc56
    --- /dev/null
    +++ b/foo
    @@ -0,0 +1 @@
    +foo
    (1/1) Stage addition [y,n,q,a,d,p,?]? n
    $ git log --stat --oneline
    7cebe64 (HEAD -> main) original
     foo | 1 +
     1 file changed, 1 insertion(+)
    d1582f3 split-out commit
     bar | 1 +
     1 file changed, 1 insertion(+)

GIT

Part of the git(1) suite