668ce - 2y
Let’s say BIP300 is activated via MASF, people start using sidechains, and the blocks are mined. The Bitcoin timechain continues. If another group says they have a version of Bitcoin Core that doesn’t have drivechain, but it does have something like CTV, then that is a hard fork. It is no longer compatible with the longest timechain, because it is not backwards compatible with BIP300.
0575b - 2y
couldnt you make the same argument with how segwit got activated?
SegWit was different. The big blockers had a hard fork and both were being mined at the same time. The hard fork wasn’t backwards compatible, so older nodes couldn’t validate the blocks. When SegWit activated, it had the acceptance of both updated nodes, and the legacy nodes that refused to upgrade. So it did not break the timechain at all.
so CTV is a hardfork?
semisol @semisol - 2y
the longest chain is not always the right chain. otherwise forced MASFs could happen
No not at all. CTV is a proposed soft fork. I’m saying if there is a version of Bitcoin Core that has CTV, but doesn’t have TapRoot, that would be a hard fork because it’s not backwards compatible with the timechain.
because in the case the timechain is with taproot and a version without taproot would be a hard fork because there are already blocks with taproot!?
Yes, so right now CTV is a proposed soft fork. It would work with all of the nodes if implemented. TapRoot has already had blocks mined, so it is the continuation of the timechain. If a new version of Core comes out, and it doesn’t have TapRoot but has CTV, then even though it’s a soft fork of a previous Core version, it is a hard fork from the timechain because it wouldn’t be backwards compatible with the blocks mined with TapRoot transactions.
