From owner-cvs-src@FreeBSD.ORG Fri Oct 26 15:45:33 2007 Return-Path: Delivered-To: cvs-src@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0456016A46C; Fri, 26 Oct 2007 15:45:33 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from speedfactory.net (mail6.speedfactory.net [66.23.216.219]) by mx1.freebsd.org (Postfix) with ESMTP id 5F73B13C48E; Fri, 26 Oct 2007 15:45:32 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from server.baldwin.cx (unverified [66.23.211.162]) by speedfactory.net (SurgeMail 3.8p) with ESMTP id 216226674-1834499 for multiple; Fri, 26 Oct 2007 11:47:40 -0400 Received: from localhost.corp.yahoo.com (john@localhost [127.0.0.1]) (authenticated bits=0) by server.baldwin.cx (8.13.8/8.13.8) with ESMTP id l9QFiftv036512; Fri, 26 Oct 2007 11:44:59 -0400 (EDT) (envelope-from jhb@FreeBSD.org) From: John Baldwin To: Scott Long Date: Fri, 26 Oct 2007 11:44:33 -0400 User-Agent: KMail/1.9.6 References: <200710150951.l9F9pUm7026506@repoman.freebsd.org> <20071025233536.B99770@fledge.watson.org> <472120E8.90504@samsco.org> In-Reply-To: <472120E8.90504@samsco.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200710261144.34645.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-2.0.2 (server.baldwin.cx [127.0.0.1]); Fri, 26 Oct 2007 11:44:59 -0400 (EDT) X-Virus-Scanned: ClamAV 0.91.2/4600/Fri Oct 26 10:02:30 2007 on server.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-4.4 required=4.2 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.1.3 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on server.baldwin.cx Cc: src-committers@FreeBSD.org, d@delphij.net, Andrey Chernov , cvs-all@FreeBSD.org, Robert Watson , cvs-src@FreeBSD.org Subject: Re: cvs commit: src/lib/libc/locale utf8.c X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 26 Oct 2007 15:45:33 -0000 On Thursday 25 October 2007 07:04:08 pm Scott Long wrote: > Robert Watson wrote: > > On Thu, 25 Oct 2007, Andrey Chernov wrote: > > > >> On Thu, Oct 25, 2007 at 12:05:40PM -0700, LI Xin wrote: > >>> Well, I think the problem is not exposing a new symbol by itself, but > >>> __mb_sb_limit is being used in _ctype.h, in a form of __inline > >>> functions. Therefore, the change will break new binaries running on > >>> older systems. > >> > >> Yes. Only vice versa compatibility supported. > > > > I think the issue here is that the change occurred very quickly after > > the branch, and when users wanted to 'change gears' back to RELENG_7 > > from HEAD once it was created immediately ran into the problem. It > > seems like a useful piece of post-branch advice to developers in the > > future will be, "Please don't do things that make switching branches -- > > back or forward -- for the first few weeks after the branch is > > created". In general, I don't think we care about forward > > compatibility, but we are currently getting lots of reports because this > > is one of those few times where a lot of moving backward happens. > > > > We do care about forward compatibility within STABLE branches, as Ken > and I have discussed in side threads. But yes, forward compat between > major branches is merely desired; i.e. changes will happen, and > hopefully not for gratuitous reasons. If we care about forward compatiblity then we can't add new features to RELENG_X branches. For example, MFCing MSI to 6.x broke forward compat since a 6.3 module might call the MSI methods thus can't be used on a 6.2 kernel. AFAIK, we have _never_ promised anything wrt forward compat, only backwards ABI compat. I can agree with Robert above that during a transition time such as now it's really handy to be able to switch easily between branches, but I didn't think it was ever a concern otherwise. If we are going to change the policy for that then there's a whole bunch of crap I need to go back out of 6.x to restore compat. :-/ -- John Baldwin