Z:gnu-www-ja-assigning-copyright--560127-It is up to you which of these/en

It is up to you which of these activities to permit, but here are the FSF's recommendations. If you plan to make major contributions to the project, insist that the contribution agreement require that software versions including your contributions be available to the public under a free software license. This will allow the developer to sell exceptions, but prevent it from using your contributions in software that is only available under a proprietary license.