# Run with 'changeAuthor "{old email}" "{new name}" "{new email}"
changeAuthor() {
    WRONG_EMAIL="$1"
    NEW_NAME="$2"
    NEW_EMAIL="$3"

    git filter-branch -f --env-filter '
        if [ $GIT_COMMITTER_EMAIL = $WRONG_EMAIL ]
        then
            export GIT_COMMITTER_NAME="${NEW_NAME}"
            export GIT_COMMITTER_EMAIL=$NEW_EMAIL
        fi
        if [ $GIT_AUTHOR_EMAIL = $WRONG_EMAIL ]
        then
            export GIT_AUTHOR_NAME="${NEW_NAME}"
            export GIT_AUTHOR_EMAIL=$NEW_EMAIL
        fi
    ' --tag-name-filter cat -- --branches --tags
}