From patchwork Wed Jan 5 17:27:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Elijah Newren X-Patchwork-Id: 12704541 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 85308C433FE for ; Wed, 5 Jan 2022 17:27:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242223AbiAER1p (ORCPT ); Wed, 5 Jan 2022 12:27:45 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54626 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242206AbiAER1l (ORCPT ); Wed, 5 Jan 2022 12:27:41 -0500 Received: from mail-wm1-x332.google.com (mail-wm1-x332.google.com [IPv6:2a00:1450:4864:20::332]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0D59FC061245 for ; Wed, 5 Jan 2022 09:27:41 -0800 (PST) Received: by mail-wm1-x332.google.com with SMTP id k66-20020a1ca145000000b00345fa984108so3707325wme.2 for ; Wed, 05 Jan 2022 09:27:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:in-reply-to:references:from:date:subject:fcc :content-transfer-encoding:mime-version:to:cc; bh=7GoB9E//7sqZ3qsTLDJp/wclKZXAI4SgsQ5Qaeegepk=; b=QPppUko9E1HRHDI0weHL1Y+YIMXaFEL3kH/Uuc9DOpo5PiXih3mcvp9USNoI0zsstE a9OcLw4gortFE2xrKaqYriVO8pt/BipWYbCyeEQ6vb9zsx+/UjNdyCyYOY/c/Iib4U07 DyIJG6yFSIsuqoTB+2lI/ITWQVevyFCs2M23Xf7eHjc07QWHRVklmFRKUCr62OArZTHF BKECspYPzM9RckfE647y635rbVH5DKy6nukOSIzF33T4CjR4C//Br56gUnKnmbEh0vlU HGCPrJLd3SAq1vKb4o7fya8LwbP19xHDLI5o/8lbyb28hLS4y2gkC1hwwKGgPNKrY3mc l8QQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:in-reply-to:references:from:date :subject:fcc:content-transfer-encoding:mime-version:to:cc; bh=7GoB9E//7sqZ3qsTLDJp/wclKZXAI4SgsQ5Qaeegepk=; b=14bIo+ERvcsbFFLMvXA3Xd0OG7Kp8v1I+5325IJ0lKcYA1dCGk/kWdsLFz89MwloP2 WfFtocy9a6MYCmWk50aeHuTKPCIQ+oATpPqELJ70HtK2q6I9xVgIvHV5TeVLUAsinaoV aFGeXm7ifBIC7dM/EQ+bMmrFCVo5z1FHhL01JzFs6aLsh37Aw9ltErvhzfQ3F5dUy3VJ OyX/Z7S1UfZERtu937qkX0gGm/tiRXPAfUmjGW6QnCa288ci7Y7ZniXhDH8iW0GiGnbN cJ7E3EcbdQu6Q7VOljOApef8EpsOGBpHfVUj5iMpCj5jBtC+KWBNncRfCHaxtF6M6783 S8lA== X-Gm-Message-State: AOAM531Kl2ZIR6hX1MRuwPRtjXHEOFobY5Bi7QNg0Xf+YWKOQWd4UMYS F+MDlyRR4HoReRzop854duUP+N+ZpXU= X-Google-Smtp-Source: ABdhPJwpf7gQzMHE2ZWa5TXAp/szNihC/P561a+Mm8vSRn2gR45cUwVGoVFz3F9Sg2qDihd+HOm4xQ== X-Received: by 2002:a7b:c058:: with SMTP id u24mr3716075wmc.90.1641403659362; Wed, 05 Jan 2022 09:27:39 -0800 (PST) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id x8sm2921905wmj.44.2022.01.05.09.27.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 05 Jan 2022 09:27:39 -0800 (PST) Message-Id: <1710ba4a9e432e2a854579c4c929e7f2cfc92211.1641403655.git.gitgitgadget@gmail.com> In-Reply-To: References: Date: Wed, 05 Jan 2022 17:27:31 +0000 Subject: [PATCH v2 4/8] merge-tree: implement real merges Fcc: Sent MIME-Version: 1.0 To: git@vger.kernel.org Cc: Christian Couder , Taylor Blau , Johannes Altmanninger , Elijah Newren , Elijah Newren , Elijah Newren Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Elijah Newren From: Elijah Newren This adds the ability to perform real merges rather than just trivial merges (meaning handling three way content merges, recursive ancestor consolidation, renames, proper directory/file conflict handling, and so forth). However, unlike `git merge`, the working tree and index are left alone and no branch is updated. The only output is: - the toplevel resulting tree printed on stdout - exit status of 0 (clean) or 1 (conflicts present) This output is mean to be used by some higher level script, perhaps in a sequence of steps like this: NEWTREE=$(git merge-tree --real $BRANCH1 $BRANCH2) test $? -eq 0 || die "There were conflicts..." NEWCOMMIT=$(git commit-tree $NEWTREE -p $BRANCH1 -p $BRANCH2) git update-ref $BRANCH1 $NEWCOMMIT Note that higher level scripts may also want to access the conflict/warning messages normally output during a merge, or have quick access to a list of files with conflicts. That is not available in this preliminary implementation, but subsequent commits will add that ability. Signed-off-by: Elijah Newren --- Documentation/git-merge-tree.txt | 28 +++++++---- builtin/merge-tree.c | 55 +++++++++++++++++++++- t/t4301-merge-tree-real.sh | 81 ++++++++++++++++++++++++++++++++ 3 files changed, 153 insertions(+), 11 deletions(-) create mode 100755 t/t4301-merge-tree-real.sh diff --git a/Documentation/git-merge-tree.txt b/Documentation/git-merge-tree.txt index 58731c19422..5823938937f 100644 --- a/Documentation/git-merge-tree.txt +++ b/Documentation/git-merge-tree.txt @@ -3,26 +3,34 @@ git-merge-tree(1) NAME ---- -git-merge-tree - Show three-way merge without touching index +git-merge-tree - Perform merge without touching index or working tree SYNOPSIS -------- [verse] +'git merge-tree' --real 'git merge-tree' DESCRIPTION ----------- -Reads three tree-ish, and output trivial merge results and -conflicting stages to the standard output. This is similar to -what three-way 'git read-tree -m' does, but instead of storing the -results in the index, the command outputs the entries to the -standard output. +Performs a merge, but does not make any new commits and does not read +from or write to either the working tree or index. -This is meant to be used by higher level scripts to compute -merge results outside of the index, and stuff the results back into the -index. For this reason, the output from the command omits -entries that match the tree. +The first form will merge the two branches, doing a full recursive +merge with rename detection. If the merge is clean, the exit status +will be `0`, and if the merge has conflicts, the exit status will be +`1`. The output will consist solely of the resulting toplevel tree +(which may have files including conflict markers). + +The second form is meant for backward compatibility and will only do a +trival merge. It reads three tree-ish, and outputs trivial merge +results and conflicting stages to the standard output in a semi-diff +format. Since this was designed for higher level scripts to consume +and merge the results back into the index, it omits entries that match +. The result of this second form is is similar to what +three-way 'git read-tree -m' does, but instead of storing the results +in the index, the command outputs the entries to the standard output. GIT --- diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c index e1d2832c809..ac50f3d108b 100644 --- a/builtin/merge-tree.c +++ b/builtin/merge-tree.c @@ -2,6 +2,9 @@ #include "builtin.h" #include "tree-walk.h" #include "xdiff-interface.h" +#include "help.h" +#include "commit-reach.h" +#include "merge-ort.h" #include "object-store.h" #include "parse-options.h" #include "repository.h" @@ -392,7 +395,57 @@ struct merge_tree_options { static int real_merge(struct merge_tree_options *o, const char *branch1, const char *branch2) { - die(_("real merges are not yet implemented")); + struct commit *parent1, *parent2; + struct commit_list *common; + struct commit_list *merge_bases = NULL; + struct commit_list *j; + struct merge_options opt; + struct merge_result result = { 0 }; + + parent1 = get_merge_parent(branch1); + if (!parent1) + help_unknown_ref(branch1, "merge", + _("not something we can merge")); + + parent2 = get_merge_parent(branch2); + if (!parent2) + help_unknown_ref(branch2, "merge", + _("not something we can merge")); + + init_merge_options(&opt, the_repository); + /* + * TODO: Support subtree and other -X options? + if (use_strategies_nr == 1 && + !strcmp(use_strategies[0]->name, "subtree")) + opt.subtree_shift = ""; + for (x = 0; x < xopts_nr; x++) + if (parse_merge_opt(&opt, xopts[x])) + die(_("Unknown strategy option: -X%s"), xopts[x]); + */ + + opt.show_rename_progress = 0; + + opt.branch1 = merge_remote_util(parent1)->name; /* or just branch1? */ + opt.branch2 = merge_remote_util(parent2)->name; /* or just branch2? */ + + /* + * Get the merge bases, in reverse order; see comment above + * merge_incore_recursive in merge-ort.h + */ + common = get_merge_bases(parent1, parent2); + for (j = common; j; j = j->next) + commit_list_insert(j->item, &merge_bases); + + /* + * TODO: notify if merging unrelated histories? + if (!common) + fprintf(stderr, _("merging unrelated histories")); + */ + + merge_incore_recursive(&opt, merge_bases, parent1, parent2, &result); + printf("%s\n", oid_to_hex(&result.tree->object.oid)); + merge_switch_to_result(&opt, NULL, &result, 0, 0); + return result.clean ? 0 : 1; } int cmd_merge_tree(int argc, const char **argv, const char *prefix) diff --git a/t/t4301-merge-tree-real.sh b/t/t4301-merge-tree-real.sh new file mode 100755 index 00000000000..f7aa310f8c1 --- /dev/null +++ b/t/t4301-merge-tree-real.sh @@ -0,0 +1,81 @@ +#!/bin/sh + +test_description='git merge-tree --real' + +. ./test-lib.sh + +# This test is ort-specific +GIT_TEST_MERGE_ALGORITHM=ort +export GIT_TEST_MERGE_ALGORITHM + +test_expect_success setup ' + test_write_lines 1 2 3 4 5 >numbers && + echo hello >greeting && + echo foo >whatever && + git add numbers greeting whatever && + git commit -m initial && + + git branch side1 && + git branch side2 && + + git checkout side1 && + test_write_lines 1 2 3 4 5 6 >numbers && + echo hi >greeting && + echo bar >whatever && + git add numbers greeting whatever && + git commit -m modify-stuff && + + git checkout side2 && + test_write_lines 0 1 2 3 4 5 >numbers && + echo yo >greeting && + git rm whatever && + mkdir whatever && + >whatever/empty && + git add numbers greeting whatever/empty && + git commit -m other-modifications +' + +test_expect_success 'Content merge and a few conflicts' ' + git checkout side1^0 && + test_must_fail git merge side2 && + cp .git/AUTO_MERGE EXPECT && + E_TREE=$(cat EXPECT) && + + git reset --hard && + test_must_fail git merge-tree --real side1 side2 >RESULT && + R_TREE=$(cat RESULT) && + + # Due to differences of e.g. "HEAD" vs "side1", the results will not + # exactly match. Dig into individual files. + + # Numbers should have three-way merged cleanly + test_write_lines 0 1 2 3 4 5 6 >expect && + git show ${R_TREE}:numbers >actual && + test_cmp expect actual && + + # whatever and whatever~ should have same HASHES + git rev-parse ${E_TREE}:whatever ${E_TREE}:whatever~HEAD >expect && + git rev-parse ${R_TREE}:whatever ${R_TREE}:whatever~side1 >actual && + test_cmp expect actual && + + # greeting should have a merge conflict + git show ${E_TREE}:greeting >tmp && + cat tmp | sed -e s/HEAD/side1/ >expect && + git show ${R_TREE}:greeting >actual && + test_cmp expect actual +' + +test_expect_success 'Barf on misspelled option' ' + # Mis-spell with single "s" instead of double "s" + test_expect_code 129 git merge-tree --real --mesages FOOBAR side1 side2 2>expect && + + grep "error: unknown option.*mesages" expect +' + +test_expect_success 'Barf on too many arguments' ' + test_expect_code 129 git merge-tree --real side1 side2 side3 2>expect && + + grep "^usage: git merge-tree" expect +' + +test_done