From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.3 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 08BCA1F859 for ; Wed, 7 Sep 2016 22:51:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751724AbcIGWvP (ORCPT ); Wed, 7 Sep 2016 18:51:15 -0400 Received: from relay6-d.mail.gandi.net ([217.70.183.198]:33901 "EHLO relay6-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751099AbcIGWvO (ORCPT ); Wed, 7 Sep 2016 18:51:14 -0400 Received: from mfilter18-d.gandi.net (mfilter18-d.gandi.net [217.70.178.146]) by relay6-d.mail.gandi.net (Postfix) with ESMTP id 64104FB882; Thu, 8 Sep 2016 00:51:11 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at mfilter18-d.gandi.net Received: from relay6-d.mail.gandi.net ([IPv6:::ffff:217.70.183.198]) by mfilter18-d.gandi.net (mfilter18-d.gandi.net [::ffff:10.0.15.180]) (amavisd-new, port 10024) with ESMTP id 8RrQ-Wt8LLk2; Thu, 8 Sep 2016 00:51:09 +0200 (CEST) X-Originating-IP: 50.39.163.18 Received: from x (50-39-163-18.bvtn.or.frontiernet.net [50.39.163.18]) (Authenticated sender: josh@joshtriplett.org) by relay6-d.mail.gandi.net (Postfix) with ESMTPSA id E3356FB877; Thu, 8 Sep 2016 00:51:06 +0200 (CEST) Date: Wed, 7 Sep 2016 15:51:04 -0700 From: Josh Triplett To: Jeff King Cc: git@vger.kernel.org, Michael Haggerty , Kevin Willford , Xiaolong Ye , Johannes Schindelin Subject: Re: [RFC/PATCH v2 0/3] patch-id for merges Message-ID: <20160907225104.f5wi2yo4d2f26tti@x> References: <20160907075346.z6wtmqnfc6bsunjb@sigill.intra.peff.net> <20160907220101.hwwutkiagfottbdd@sigill.intra.peff.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160907220101.hwwutkiagfottbdd@sigill.intra.peff.net> User-Agent: NeoMutt/ (1.7.0) Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Wed, Sep 07, 2016 at 06:01:01PM -0400, Jeff King wrote: > Here's a re-roll of the series I posted at: > > http://public-inbox.org/git/20160907075346.z6wtmqnfc6bsunjb@sigill.intra.peff.net/ > > Basically, it drops the time for "format-patch --cherry-pick" on a > particular case from 3 minutes down to 3 seconds, by avoiding diffs > on merge commits. Compared to v1, it fixes the totally-broken handling > of commit_patch_id() pointed out by Johannes. > > We can drop the diffs on the merge commits because they're quite broken, > as discussed in the commit message of patch 3 (they don't take into > account any parent except the first). So what do we do when somebody > asks for the patch-id of a merge commit? > > This is still marked RFC, because there are really two approaches here, > and I'm not sure which one is better for "format-patch --base". I'd like > to get input from Xiaolong Ye (who worked on --base), and Josh Triplett > (who has proposed some patches in that area, and is presumably using > them). Thanks. I'd love to see a more resilient patch-id mechanism, to make it easier to match up patches between branches. I don't think it makes sense to talk about the patch-id of a merge commit (though it might make sense for a merge which makes additional changes not present in any of the parents). Even if someone wants to match up merge commits with merge commits, I don't think that should happen via patch-id; I think that should happen in terms of "what patches does this merge introduce", without constructing a merge-patch-id via a Merkle tree of commit patch-ids. So, I think this patch series makes sense (modulo the comments about the commit message in patch 3). We already don't respect merge commits when doing format-patch; this seems consistent with that. If we ever make it possible for format-patch to handle merge commits, then we should also allow it to have merge commits as prerequisites. - Josh Triplett