Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of dashjr.org
	designates 85.234.147.28 as permitted sender)
	client-ip=85.234.147.28; envelope-from=luke@dashjr.org;
	helo=zinan.dashjr.org; 
From: Luke Dashjr <luke@dashjr.org>
To: bitcoin-development@lists.sourceforge.net
Date: Wed, 27 May 2015 03:46:15 +0000
User-Agent: KMail/1.13.7 (Linux/3.14.41-gentoo; KDE/4.14.3; x86_64; ; )
References: <CAPg+sBg5TqQ=zjyZ7dp-d1oBGp31Krnix3zyt9suP4-AGbxW=Q@mail.gmail.com>
In-Reply-To: <CAPg+sBg5TqQ=zjyZ7dp-d1oBGp31Krnix3zyt9suP4-AGbxW=Q@mail.gmail.com>
MIME-Version: 1.0
Content-Type: Text/Plain;
  charset="iso-8859-15"
Content-Transfer-Encoding: 7bit
Message-Id: <201505270346.17014.luke@dashjr.org>
Subject: Re: [Bitcoin-development] Version bits proposal
Precedence: list

On Wednesday, May 27, 2015 1:48:05 AM Pieter Wuille wrote:
> Feel free to comment. As the gist does not support notifying participants
> of new comments, I would suggest using the mailing list instead.

I suggest adding a section describing how this interacts with and changes GBT.

Currently, the client tells the server what the highest block version it 
supports is, and the server indicates a block version to use in its template, 
as well as optional instructions for the client to forcefully use this version 
despite its own maximum version number. Making the version a bitfield 
contradicts the increment-only assumption of this design, and since GBT 
clients are not aware of overall network consensus state, reused bits can 
easily become confused. I suggest, therefore, that GBT clients should indicate 
(instead of a maximum supported version number) a list of softforks by 
identifier keyword, and the GBT server respond with a template indicating:
- An object of softfork keywords to bit values, that the server will accept.
- The version number, as presently conveyed, indicating the preferred softfork 
flags.

Does this sound reasonable, and/or am I missing anything else?

Luke