Quote from: CIYAM on March 27, 2016, 03:18:24 AM

It was explained to you that the op code is *valid* in the context of validating a block (so of course the block would not be rejected by older software). Why do you think it is called a NOP?

It's called a "No OPeration" because it doesn't do anything (except maybe wait a clock cycle or so) in the context of script execution.. So it will not influence the result of the script execution. However there could still be a consensus rule that says: scripts shall not contain NOP instructions.

What exactly is the "context of validating" a block? Validating it for wether it should be included in finding the longest chain? So are you saying a block containing a tx with a NOP will be accepted as part of the longest valid chain by core 0.11, 0.12?

Quote from: CIYAM on March 27, 2016, 05:04:50 AM

There are different validation rules depending upon whether you are mining, relaying or verifying a block (i.e. context).

So the rule about a NOP is not the same rule in all three situations (something that you just don't seem to be able to grok).

I understand that. For example BitcoinUnlimited will not relay some blocks if they are too big for the values given in configuration, yet it will still accept it as a valid block for mining.

Quote from: gmaxwell on March 24, 2016, 05:24:27 PM

The primary established mechanism for safe softforks is the reserved script NOPs (which will not be relayed or mined by unmodified software today)

so maxwell here seems to be saying that in the context of relaying a tx, relaying a block and mining, a tx containting a NOP (is that any different from "a reserved script NOP", btw?) instruction or a block containing a tx containing a NOP instruction will not be relayed (in case of a block or tx) and will not be considered when finding the 'longest' chain to mine on? That seems hard to believe. So I'm putting a NOP into a script and that means the tx wont be relayed by standard core nodes and it wont be mined by a miner who runs a core node? Is that what he's saying? Is it true?