git-cherry-pick-backdate.py

#!/usr/bin/env python3

import subprocess
import sys


def git_author_date(commit):
    return subprocess.check_output(['git', 'show', '--format=%aD', '--no-patch', commit]).decode("utf-8").strip()


def git_author_email(commit):
    return subprocess.check_output(['git', 'show', '--format=%ae', '--no-patch', commit]).decode("utf-8").strip()


def git_author_name(commit):
    return subprocess.check_output(['git', 'show', '--format=%an', '--no-patch', commit]).decode("utf-8").strip()


def git_committer_date(commit):
    return subprocess.check_output(['git', 'show', '--format=%cD', '--no-patch', commit]).decode("utf-8").strip()


def git_committer_email(commit):
    return subprocess.check_output(['git', 'show', '--format=%ce', '--no-patch', commit]).decode("utf-8").strip()


def git_committer_name(commit):
    return subprocess.check_output(['git', 'show', '--format=%cn', '--no-patch', commit]).decode("utf-8").strip()


def git_committer_name(commit):
    return subprocess.check_output(['git', 'show', '--format=%cn', '--no-patch', commit]).decode("utf-8").strip()


def git_cherry_pick(commit, author_date, author_email, author_name, committer_date, committer_email, committer_name):
    subprocess.check_call(['git', 'cherry-pick', commit], env={
        "GIT_AUTHOR_DATE": author_date,
        "GIT_AUTHOR_EMAIL": author_email,
        "GIT_AUTHOR_NAME": author_name,
        "GIT_COMMITTER_DATE": committer_date,
        "GIT_COMMITTER_EMAIL": committer_email,
        "GIT_COMMITTER_NAME": committer_name,
    })


def main(argv):
    if len(argv) < 2:
        return 1

    for commit in argv[1:]:
        author_date = git_author_date(commit)
        author_email = git_author_email(commit)
        author_name = git_author_name(commit)
        committer_date = git_committer_date(commit)
        committer_email = git_committer_email(commit)
        committer_name = git_committer_name(commit)
        print("commit {}".format(commit))
        print("Author: {} <{}> {}".format(author_name, author_email, author_date))
        print("Committer: {} <{}> {}".format(committer_name, committer_email, committer_date))
        print("")
        git_cherry_pick(commit, author_date, author_email, author_name, committer_date, committer_email, committer_name)


if __name__ == '__main__':
    sys.exit(main(sys.argv))