[nerdponx]

That makes sense. Thanks for clarifying.

I imagine this could be an issue if, say, it's a project like Firefox and they start including some binary blobs. Without an explicit CLA, couldn't a FOSS-zealot contributor now sue to have their code excised from the product?

[maxlybbert]

For the record, I'm not a lawyer. If I understand the question correctly, I believe the argument would be that the contributor believed all contributors were on equal footing (e.g., all contributions had to comply with the same rules) or that the project somehow promised to behave a certain way -- and that promise may have been included in the license. Without a separate explicit promise about how the project would act in the future, I wouldn't expect the lawsuit to go anywhere, but I don't think it's a silly argument, and it may have a better chance than I believe.

Broadly speaking, the CLAs I've seen either (1) fall into the classic legal "belt and suspenders" approach of being explicit where there is arguably an implicit promise, or (2) require the contributor to transfer copyright to the project and then make promises about what the project will do with the code, including promises about relicensing, and a broad license back to the original contributor.

US copyright law sometimes assumes that there is some kind of agreement between people who collaborate on a copyrightable project, and generally speaking, the CLA looks like it serves that purpose.

[maxlybbert]

Your question is based on a common assumption, that you asked about a couple of days ago. In the US, at least, there are two ways multiple people can hold copyright on something: (1) if each contribution is independent, like a magazine or encyclopedia article, you have a collective copyright; (2) if each contribution is meant to merge with the others, you have a joint copyright. The rules for collective copyrights are basically what programmers seem to expect for collaborative works: each contributor owns copyright on their particular contribution.

However, I believe most open source projects are actually joint works, and the rules for joint copyrights are wildly different from what programmers seem to expect (e.g., http://copyright.universityofcalifornia.edu/ownership/joint-... , but you can find other explanations online, including at http://copyright.gov ). It's clear to me that the law assumes people who collaborate on a joint work will have some kind of agreement between them, like a CLA. I'm not able to find it right now, but I'm aware of one case where somebody contributed to a proprietary program, declared that made him a joint copyright holder, and started selling copies of the software without permission. The court agreed that if he had been a joint owner he would have had authority to sell copies without coordinating with the other owners, but the court decided he only had copyright in his contribution, like a collective work, not because the contribution could stand alone, but because it was relatively small and easily identified.

Based on that ruling, if I maintained an open source project under some kind of restrictive license that I intended to enforce, I wouldn't worry about getting a CLA for small patches (aside from getting some statement that they had authority to offer the contribution), but I would worry about getting one from regular contributors.

There is some point when a contributor crosses a threshold and becomes a joint owner. You want a clear agreement between the joint owners, but I don't believe the license is the right place for that agreement.