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=-2.7 required=3.0 tests=AWL,BAYES_00, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_HI,T_RP_MATCHES_RCVD shortcircuit=no autolearn=no 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 1EE5D1FADF for ; Thu, 18 Jan 2018 15:35:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932662AbeARPfm (ORCPT ); Thu, 18 Jan 2018 10:35:42 -0500 Received: from mout.gmx.net ([212.227.15.19]:54196 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932640AbeARPfi (ORCPT ); Thu, 18 Jan 2018 10:35:38 -0500 Received: from [10.122.129.233] ([46.142.197.184]) by mail.gmx.com (mrgmx001 [212.227.17.190]) with ESMTPSA (Nemesis) id 0MA9Yv-1eVpVv0PNp-00BOAI; Thu, 18 Jan 2018 16:35:34 +0100 Date: Thu, 18 Jan 2018 16:35:34 +0100 (STD) From: Johannes Schindelin X-X-Sender: virtualbox@MININT-6BKU6QN.europe.corp.microsoft.com To: git@vger.kernel.org cc: Junio C Hamano , Jacob Keller Subject: [PATCH 3/8] sequencer: fast-forward merge commits, if possible In-Reply-To: Message-ID: <9878bd57cc82daf08309943305460c1e8a050518.1516225925.git.johannes.schindelin@gmx.de> References: User-Agent: Alpine 2.21.1 (DEB 209 2017-03-23) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Provags-ID: V03:K0:kjL5xEEhGIYL4Q3kSDqnRCB19R5xpKEa+hmbaRC7jqZReT9Uq/B MZCB70N7EBIN0lNd9qpF3GmRCFHkrjg2Wt1wUR+Kg6NxAo+WDZ3REdrKFd4exyygquTvYdk C3mNcvPLxneQJJy3/TmaIfyvYJS4I4ROF0LycoQTzuZPMA2DXxtsjeDcjGqsavPY4Qrb53A Tj3rk3T/LwRSK0G5qNlkA== X-UI-Out-Filterresults: notjunk:1;V01:K0:+cQZwjnjcpE=:0HCyivH4xgGP8q5G5h5OIg PtJx/fFQY3IbUqGRZRMorJYpiY//R+82UE8YdTFEmZHwtDrKyQ/vbD8CpNnku2wxrbSOZqJTZ eoMk2KiW4egHvwCGOqXhfMeSH3v/y33xaF05KMB1fYIpVJqULdf4E5P7YM3Xp1Uzc84ypR+ws 8Ter3f0uN3J2x4HWsBdS4CbNtv5GhvsmgpeIGcY5Hp0TNSrsslrSg8EDdiBQ8JJFNs1ob6S01 oRKTp9hN6AlT1t3w0LElMQodeYNurt940ZzTPjki027urNqn79DdiwJPiwktVR//UT6hJ3JyT LsGPjWAfZJIkl0Ai04aaaaGHwhxpQ9O7lfRFIhbmAh0ynRRk1JftZzN/4RXigXC35L4qZmvlx Lzz5JIqKLXwzvJ3omtNJlmB8naYFVx/ggKR3H+pKPXFdNwD8DeWAhkbSYKnnCuwrLljTXsqC5 b3qr9JhNRDx9vAKhZPIh0XZQWf0Li3HZ/2NJIY4M/so8hlpdts03F7trKH6C884mjtk2vHi3y DjzygmiSPejRzS+sqvqDBCHe7XiItZZ2fqoeiW7KE8MUsJbLDIm7wMQgkEg3lvcKFE6aQH7pc B+2nHDMh0P/xU7hVMC98mN/pYAdcJ/pQ7VPIBlLwOhD+Fliqsb3d1Ev3Nom0kmXC186/jdNHU Yvgm9LxsuUgcoCJFxXdh+mC/MbPCxBBxTQOuGWbf50r8Ly11OwRwRsr3vdcZr943GggmOJXFd MwhdS9heQ3Z0wm2PF4uzAo7i+DmqEbS09V0XAvrRLfxzHly1CwPWtvgP8qdpIWT39C12AgkWY Gy1mvT4LX+4gyWu3VLFgN5nTVO9IGndh66H3PlBH0i7C+tYCaw= Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Just like with regular `pick` commands, if we are trying to recreate a merge commit, we now test whether the parents of said commit match HEAD and the commits to be merged, and fast-forward if possible. This is not only faster, but also avoids unnecessary proliferation of new objects. Signed-off-by: Johannes Schindelin --- sequencer.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/sequencer.c b/sequencer.c index 567cfcbbe8b..a96255426e7 100644 --- a/sequencer.c +++ b/sequencer.c @@ -2085,7 +2085,7 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len, struct commit *head_commit, *merge_commit, *i; struct commit_list *common, *j, *reversed = NULL; struct merge_options o; - int ret; + int can_fast_forward, ret; static struct lock_file lock; for (merge_arg_len = 0; merge_arg_len < arg_len; merge_arg_len++) @@ -2151,6 +2151,14 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len, return error(_("Cannot merge without a current revision")); } + /* + * If HEAD is not identical to the parent of the original merge commit, + * we cannot fast-forward. + */ + can_fast_forward = commit && commit->parents && + !oidcmp(&commit->parents->item->object.oid, + &head_commit->object.oid); + strbuf_addf(&ref_name, "refs/rewritten/%.*s", merge_arg_len, arg); merge_commit = lookup_commit_reference_by_name(ref_name.buf); if (!merge_commit) { @@ -2164,6 +2172,17 @@ static int do_merge(struct commit *commit, const char *arg, int arg_len, rollback_lock_file(&lock); return -1; } + + if (can_fast_forward && commit->parents->next && + !commit->parents->next->next && + !oidcmp(&commit->parents->next->item->object.oid, + &merge_commit->object.oid)) { + strbuf_release(&ref_name); + rollback_lock_file(&lock); + return fast_forward_to(&commit->object.oid, + &head_commit->object.oid, 0, opts); + } + write_message(oid_to_hex(&merge_commit->object.oid), GIT_SHA1_HEXSZ, git_path_merge_head(), 0); write_message("no-ff", 5, git_path_merge_mode(), 0); -- 2.15.1.windows.2.1430.ga56c4f9e2a9