This is a follow up question to an earlier question which included a misunderstanding about the nature of the MIT/X license, and has been clarified there.
Suppose Alice makes some changes to dwm. The changes could be conveniently distributed as either a patch file, or as a fork of the original repository. Suppose that Alice's changes make no alteration to the existing license of dwm. Her fork would include the same license statement that the original project did. Then I think that:
- Alice's forks to dwm are clearly licensed as MIT/X.
- Alice's patches, taken by themselves, have all rights reserved.
It follows that as long as no fork including Alice's patch has been published by Alice, that Bob (who forked dwm and included Alice's patch in good faith), might be violating Alice's copyright by distributing his version. This sounds like a problem for managing copyright among large projects - is it a problem in practice? Is there some inference made about the fact that Alice's changes were clearly intended to patch dwm, or must some explicit agreement be made?
A license with greater copyleft in the parent project (like the GPL) does ensure that Bob's fork is allowed. Section 5 of GPLv3 states (my emphasis):
5. Conveying Modified Source Versions. You may convey a work based on the Program, **or the modifications to produce it from the Program**, in the form of source code under the terms of section 4, provided that you also meet all of these conditions: ...
Copied from previous question: Bart von Ingen Schenau wrote the following relevant detail:
There is only one situation where the default copyright "license" changes if it is known that the changes are intended to be a patch to another work. That is if the changes are offered in a pull-request to a repository that has the policy that the incoming license (the license of contributions) is the same as the outgoing license (the license under which the repository is offered). In that case, by making a pull request, Alice has agreed to license her changes under the repository's license, even when it is not explicitly stated among the changes.
They mention that GitHub is an example of a platform with such a ToS. I am interested in finding out if there are any more general considerations, in the absence of something like a ToS explicitly guaranteeing these rights.