Getting grubby with ZFS - GPLv2 or later legality
Posted Dec 10, 2010 4:36 UTC (Fri) by giraffedata
In reply to: Getting grubby with ZFS
Parent article: Getting grubby with ZFS
it seems to me that what you're implying would contradict ex post facto and "grandfathering" concepts.
Those legal doctrines don't apply because they are about criminal law. A government can't make something illegal and then punish people who have already done it. A more fuzzy version of it also says a government cannot change the meaning of an existing contract unless the government makes it really clear it means to do so. But FSF isn't a government, so it doesn't apply.
What we should be thinking of is the rule that a contract isn't enforceable if it's too speculative at the time it is executed -- i.e. the parties couldn't reasonably predict its effect. A contract can certainly require actions that are to be determined later. For example, "tenant agrees to pay for all glass breakage," even though neither party knows what breakage that will be. Or actions dependent on someone else: "tenant shall replace smoke alarm batteries," even though the batteries have to be supplied by someone else and no one knows on what terms he will offer them at the time the tenant needs to acquire one. But you can go too far. "Tenant promises to pay any bill Landlord sends him" is a promise a court would not enforce.
I don't know how enforceable "GPL v2 or later" would be (and we aren't talking about a true contract here, but a conditional license), but assuming GPL v4 is in the same spirit as v2, I can see it being sufficiently predictable that the condition would be enforceable.
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