From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Tan Subject: [PATCH v2 13/19] pull: implement pulling into an unborn branch Date: Wed, 3 Jun 2015 14:48:57 +0800 Message-ID: <1433314143-4478-14-git-send-email-pyokagan@gmail.com> References: <1433314143-4478-1-git-send-email-pyokagan@gmail.com> Cc: Stefan Beller , Johannes Schindelin , Stephen Robin , Paul Tan To: git@vger.kernel.org X-From: git-owner@vger.kernel.org Wed Jun 03 08:50:44 2015 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Z02Va-0004sO-3v for gcvg-git-2@plane.gmane.org; Wed, 03 Jun 2015 08:50:38 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753371AbbFCGue (ORCPT ); Wed, 3 Jun 2015 02:50:34 -0400 Received: from mail-pa0-f49.google.com ([209.85.220.49]:35790 "EHLO mail-pa0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753345AbbFCGuY (ORCPT ); Wed, 3 Jun 2015 02:50:24 -0400 Received: by padjw17 with SMTP id jw17so699983pad.2 for ; Tue, 02 Jun 2015 23:50:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=7p2jQaLdB7KHvc+FHaNIaLWv/tM4TNya5jWnUDI4XAw=; b=pWzk7LmVy/+7xyl12mW6G24ehy90y/VKMcG7DrAbAh37s7Opm8255UAQgkxZOmVopI A0rrxzy6taVJEBVmzSyq7535GZiOs8FK5SXsBrmzzIL6jQ+0QQmNB5bV1oQ/x8mkCfdy WK6Jok5kPdbE7j6UEugorJQnBzkLmaOMfxvPy4+tSBmCDk5LiVxdWmDe/Hi2kh/fsIc3 TjVGU3rYEET1eOjfWgNHRib/FD0CjlCVnVbIWKb5JQJFJso4VzEHbbjndNw+QuDHD4Th M3Q+7VhR7ty9fa8VqRPJiAOXwAfT92esFSlZqlHM8Tk2fvbCzYh+VXp/0/3bBnJj5E3g iO2w== X-Received: by 10.66.139.70 with SMTP id qw6mr56886190pab.112.1433314223703; Tue, 02 Jun 2015 23:50:23 -0700 (PDT) Received: from yoshi.pyokagan.tan ([116.86.132.138]) by mx.google.com with ESMTPSA id qt4sm19474130pbc.86.2015.06.02.23.50.20 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 02 Jun 2015 23:50:22 -0700 (PDT) X-Mailer: git-send-email 2.1.4 In-Reply-To: <1433314143-4478-1-git-send-email-pyokagan@gmail.com> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: b4dc085 (pull: merge into unborn by fast-forwarding from empty tree, 2013-06-20) established git-pull's current behavior of pulling into an unborn branch by fast-forwarding the work tree from an empty tree to the merge head, then setting HEAD to the merge head. Re-implement this behavior by introducing pull_into_void() which will be called instead of run_merge() if HEAD is invalid. Helped-by: Stephen Robin Signed-off-by: Paul Tan --- builtin/pull.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/builtin/pull.c b/builtin/pull.c index 8db0db2..f0d4710 100644 --- a/builtin/pull.c +++ b/builtin/pull.c @@ -13,6 +13,7 @@ #include "sha1-array.h" #include "remote.h" #include "dir.h" +#include "refs.h" static const char * const pull_usage[] = { N_("git pull [options] [ [...]]"), @@ -367,6 +368,27 @@ static int run_fetch(const char *repo, const char **refspecs) } /** + * "Pulls into void" by branching off merge_head. + */ +static int pull_into_void(unsigned char merge_head[GIT_SHA1_RAWSZ], + unsigned char curr_head[GIT_SHA1_RAWSZ]) +{ + /* + * Two-way merge: we claim the index is based on an empty tree, + * and try to fast-forward to HEAD. This ensures we will not lose + * index/worktree changes that the user already made on the unborn + * branch. + */ + if (checkout_fast_forward(EMPTY_TREE_SHA1_BIN, merge_head, 0)) + return 1; + + if (update_ref("initial pull", "HEAD", merge_head, curr_head, 0, UPDATE_REFS_DIE_ON_ERR)) + return 1; + + return 0; +} + +/** * Runs git-merge, returning its exit status. */ static int run_merge(void) @@ -475,5 +497,10 @@ int cmd_pull(int argc, const char **argv, const char *prefix) if (!merge_heads.nr) die_no_merge_candidates(repo, refspecs); - return run_merge(); + if (is_null_sha1(orig_head)) { + if (merge_heads.nr > 1) + die(_("Cannot merge multiple branches into empty head.")); + return pull_into_void(*merge_heads.sha1, curr_head); + } else + return run_merge(); } -- 2.1.4