Quote from: amaclin on October 15, 2015, 09:33:00 PM

This is very close to hardfork.
Yes. I do understand that it is not a hardfork in strict terms.

I don't agree, not even in the most lax of terms.

It's a standardizes rule, and already on the order of 95% of transactions were already conforming. If a wallet produces a non-conforming transaction anyone in the world can mutate it to the conforming form. Even absent the auto-mutation, when it doesn't work-- it fails safe: you can still receive transactions, but your sends may not work; and you can either update your software or find someone/something to mutate them for you. It's likely that due to 'helpful' mutation and non-upgraded nodes and miners the remainder will continue to get confirmed (with delays) for some time... and that 5% remaining should drop as electrum and armory get updates out.

I would have preferred to continue to wait to activate the filtering, which has been implemented and waiting in Bitcoin core for years now, until even more users were upgraded... but the ongoing attacks made that a poor trade-off: There is no reason that the creators of 95% of the transactions should suffer attacks because we were worried about inconveniencing the remaining 5%. I also called in this thread multiple times for help driving that 5% down to nothing and no one else cares, so-- how much can the negative impact matter when basically none of all the noisy people in this thread cared to lift a finger to help mitigate it?

All the other avenues for "nuisance mutability" that we're aware of were closed long ago, some of those also required getting wallets to update, but far fewer wallets were broken with respect to those rules. Fortunately, until recently, no one who wanted to attack had bothered figuring out how to perform this particular attack (as it's ever so slightly tricker-- can't just be done by stuffing an extra byte in a transaction); unfortunately that didn't last, and so we got to lose huge amounts of effort dealing with this and creating a small amount of additional collateral disruption instead of working on other things; the result will likely also delay the deployment of CLTV some due to difficult in getting miners to update twice in rapid succession... but thats life.