From: Luke Dashjr <luke@dashjr.org>
To: bitcoin-dev@lists.linuxfoundation.org,
	Rusty Russell <rusty@rustcorp.com.au>
Date: Thu, 10 May 2018 02:27:41 +0000
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Subject: Re: [bitcoin-dev] Making OP_TRUE standard?
Precedence: list

An OP_TRUE-only script with a low value seems like a good example of where the 
weight doesn't reflect the true cost: it uses a UTXO forever, while only 
costing a weight of 4.

I like Johnson's idea to have some template (perhaps OP_2-only, to preserve 
expected behaviour of OP_TRUE-only) that when combined with a 0-value is 
always valid only if spent in the same block.

I wonder if it would make sense to actually tie it to a transaction version 
bit, such that when the bit is set, the transaction is serialised with +1 on 
the output count and 00000000000000000181 is simply injected into the 
transaction hashing... But for now, simply having a consensus rule that a bit 
MUST be set for the expected behaviour, and the bit may ONLY be set when the 
last output is exactly 00000000000000000181, would allow us to code the 
transaction serialisation up later. (Maybe it should be the first output 
instead of the last... Is there any legitimate reason one would have multiple 
such dummy outputs?)

Luke


On Tuesday 08 May 2018 23:57:11 Rusty Russell via bitcoin-dev wrote:
> Hi all,
>
>         The largest problem we are having today with the lightning
> protocol is trying to predict future fees.  Eltoo solves this elegantly,
> but meanwhile we would like to include a 546 satoshi OP_TRUE output in
> commitment transactions so that we use minimal fees and then use CPFP
> (which can't be done at the moment due to CSV delays on outputs).
>
> Unfortunately, we'd have to P2SH it at the moment as a raw 'OP_TRUE' is
> non-standard.  Are there any reasons not to suggest such a policy
> change?
>
> Thanks!
> Rusty.
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