That would not really solve the problem. The Sun/Oracle patent grant only extends to JDKs that conform to the specification, and pass all tests in the test suite. That is, if you can license the test suite (see Apache Harmony).
It is implicit. IANAL, but it is supposedly very weak (see e.g. Novell-Microsoft deal). E.g. the European Commission, after analysis, thinks it does not protect forks. For a good explanation, see:
Yeah, these lines look great:
"OpenJDK is has been distributed by Oracle under GPLv2.[1] GPLv2 includes two implicit patent licences, so users of OpenJDK should be safe, and modified versions of OpenJDK should also be safe (even if they're heavily modified).
The protections in the GPL are unconditional. The software doesn't have to comply with any specifications in order to benefit from these protections."
That's a very interesting consequence of the GPL I hadn't considered before. I wonder where the law would draw the line in regards to modification. I mean, if I download OpenJDK, and delete 99% of it and then code something else, is it still the same software? Does my new program have the same patent protection?
> Does my new program have the same patent protection?
I would say it does to the same extent all the other GPL constraints stay in force. I think that the GPL stays in force down to the smallest unit of copyrightable code - it has to, or you would be legally unable to distribute 1% of the project on its own which makes no sense.
However this would be a big leap: Android is Apache Licensed. Bringing GPL code in to Dalvik will make it (and any other components that are linked to it) GPL licensed, which in turn force all the carriers and handset makers to distribute their own customizations. I'm not sure how far that would extend through Android's code base but it could remove one of the most attractive features of Android for vendors - the fact they can put their own proprietary technology into it and customize it how they like.