NAME

git-reparent - Recommit HEAD with a new set of parents.

SYNOPSIS

git reparent [OPTIONS] ((-p <parent>)... | --no-parent)

DESCRIPTION

Create a new commit object that has the same tree and commit message as HEAD but with a different set of parents. If --no-reset is given, the full object id of this commit is printed and the program exits; otherwise, git reset is used to update HEAD and the current branch to this new commit.

This command can be used to manually shape the history of a repository. Whereas git rebase moves around diffs, git reparent moves around snapshots. See EXAMPLES for a reason why you might want to use this command.

OPTIONS

-h, --help	show the help
-e, --edit	edit the commit message in an editor first
-m, --message <message>
	use the given message instead of that of HEAD
-p, --parent <commit>
	new parent to use; may be given multiple times
--no-parent	create a parentless commit
-q, --quiet	be quiet; only report errors
--no-reset	print the new object id instead of updating HEAD

INSTALLATION

Make executable and place somewhere in your $PATH.

EXAMPLES

Reparenting the tip of a branch

Suppose we create some commit B and then accidentally pass the --amend flag when creating new commit C, resulting in the following history:

        B
       /
...---A---C (HEAD)

What we really wanted was one linear history, ...---A--B--C. If we were to use git rebase or git cherry-pick to reconstruct the history, this would try to apply the diff of A..C onto B, which might fail. Instead, what we really want to do is use the exact message and tree from C but with parent B instead of A. To do this, we run

$ git reparent -p B

where the name B can be found by running git reflog and looking for the first "commit (amend)". The resulting history is now just what we wanted:

        C
       /
...---A---B---C' (HEAD)

Reparenting an inner commit

We can also update the parents of a commit other than the most recent. Suppose that we want to perform a rebase-like operation, moving master onto origin/master, but we want to completely ignore any changes made in the remote branch. That is, our history currently looks like this:

        B---C (master, HEAD)
       /
...---A---D---E (origin/master)

and we want to make it look like this:

        B---C   (origin/master)
       /       /
...---A---D---E---B'---C' (master, HEAD)

We can accomplish this by using git rebase --interactive along with git reparent:

$ git rebase -i A
# select the "edit" command for commit B
# git rebase will dump us out at commit B
$ git reparent -p origin/master
$ git rebase --continue

Now the history will look as desired, and the trees, commit messages, and authors of B' and C' will be identical to those of B and C, respectively.

SEE ALSO

git-filter-branch(1) combined with either git grafts or git-replace(1) can be used to achieve the same effect

git-rebase(1) can be used to re-apply the diffs of the current branch to another

AUTHOR

Mark Lodato <lodato@google.com>

Copyright 2013 Google Inc.

Distributed under the GNU General Public License, version 2.0.