[michaelmrose]

So you have a file function foo is Apache, bar calls foo. Isn't bar a derivative work of foo? Someone from canonical rewrites foo changing 4 of 7 lines. In this version is foo now canonical's contribution or still the original contributor?

A: Is it accurate to say that there is no metadata regarding who owes what because it would take millions and a trial to decide?

B: Is it accurate to say that this uncertainty is basically as good as owning the whole thing in this case because it is impossible to use it other than either under the terms of the AGPL or some commercial license from Canonical? You are obviously blameless for using the Apache code.

C: Does the inherent confusion mean that if similar features are committed to the mixed proprietary/AGPL branch the inherent complexity of deciding who owns what would make using the open source branch a minefield. EG evilcorp with a substantial budget could simply shut down the open source branch with threats of ruinously expensive lawsuits and false but not obviously false claims of infringement.

D: If A B C does this mean that ANY permissively licensed project which is partially owned by a party which presently contributes substantially to the labor could in effect take an open source project proprietary by first making it the path of least resistance to continue with their fork and later the only choice.

[DannyBee]

Short answer: No in most cases.

You can't create confusion and then sue people over the confusion. This is the purpose of copyright notice - you have to make it clear enough who owns rights to avoid various defenses.

As for your function question: Copyright was created mostly for books, remember.

As such, it gets weird quickly when applied to code.

For example - i write a book, and on page 236, it says at the top "the text of this page is copied from the folowing book <some book>" and then copies it inline.

This is probably infringement.

If i instead write a book, and on page 236, it says at the top "for the text of this page, please see page 194 of the following book <some book>" and does not copy it inline.

This is not infringement.

Now, could you currently convince a judge how shared library vs static library linking works, and that it matters? Maybe. Moreso than you could a decade ago.

[notpushkin]

> bar calls foo. Isn't bar a derivative work of foo?

I think it isn’t. Function signatures are fair use (under certain conditions, as established in Google v. Oracle), so just calling a function isn’t enough to declare your code a derivative work.

The combined work however is of course a derivative work of foo and is subject to its license terms, so if you want to be able to distribute it, you have to allow abide by them (i.e. release source code for both foo and bar if foo is AGPL, even though bar can be Apache or MIT or something; and you can’t use a more restrictive license that AGPL for bar).

If you want you can reimplement foo yourself though – then you can distribute bar together with your implementation under any license you like.

(IANAL)