src/revert.c

   1 /*
   2 * Copyright (C) the libgit2 contributors. All rights reserved.
   3 *
   4 * This file is part of libgit2, distributed under the GNU GPL v2 with
   5 * a Linking Exception. For full terms see the included COPYING file.
   6 */
   7
   8 #include "common.h"
   9 #include "repository.h"
  10 #include "filebuf.h"
  11 #include "merge.h"
  12 #include "index.h"
  13
  14 #include "git2/types.h"
  15 #include "git2/merge.h"
  16 #include "git2/revert.h"
  17 #include "git2/commit.h"
  18 #include "git2/sys/commit.h"
  19
  20 #define GIT_REVERT_FILE_MODE            0666
  21
  22 static int write_revert_head(
  23         git_repository *repo,
  24         const char *commit_oidstr)
  25 {
  26         git_filebuf file = GIT_FILEBUF_INIT;
  27         git_buf file_path = GIT_BUF_INIT;
  28         int error = 0;
  29
  30         if ((error = git_buf_joinpath(&file_path, repo->path_repository, GIT_REVERT_HEAD_FILE)) >= 0 &&
  31                 (error = git_filebuf_open(&file, file_path.ptr, GIT_FILEBUF_FORCE, GIT_REVERT_FILE_MODE)) >= 0 &&
  32                 (error = git_filebuf_printf(&file, "%s\n", commit_oidstr)) >= 0)
  33                 error = git_filebuf_commit(&file);
  34
  35         if (error < 0)
  36                 git_filebuf_cleanup(&file);
  37
  38         git_buf_free(&file_path);
  39
  40         return error;
  41 }
  42
  43 static int write_merge_msg(
  44         git_repository *repo,
  45         const char *commit_oidstr,
  46         const char *commit_msgline)
  47 {
  48         git_filebuf file = GIT_FILEBUF_INIT;
  49         git_buf file_path = GIT_BUF_INIT;
  50         int error = 0;
  51
  52         if ((error = git_buf_joinpath(&file_path, repo->path_repository, GIT_MERGE_MSG_FILE)) < 0 ||
  53                 (error = git_filebuf_open(&file, file_path.ptr, GIT_FILEBUF_FORCE, GIT_REVERT_FILE_MODE)) < 0 ||
  54                 (error = git_filebuf_printf(&file, "Revert \"%s\"\n\nThis reverts commit %s.\n",
  55                 commit_msgline, commit_oidstr)) < 0)
  56                 goto cleanup;
  57
  58         error = git_filebuf_commit(&file);
  59
  60 cleanup:
  61         if (error < 0)
  62                 git_filebuf_cleanup(&file);
  63
  64         git_buf_free(&file_path);
  65
  66         return error;
  67 }
  68
  69 static int revert_normalize_opts(
  70         git_repository *repo,
  71         git_revert_options *opts,
  72         const git_revert_options *given,
  73         const char *their_label)
  74 {
  75         int error = 0;
  76         unsigned int default_checkout_strategy = GIT_CHECKOUT_SAFE |
  77                 GIT_CHECKOUT_ALLOW_CONFLICTS;
  78
  79         GIT_UNUSED(repo);
  80
  81         if (given != NULL)
  82                 memcpy(opts, given, sizeof(git_revert_options));
  83         else {
  84                 git_revert_options default_opts = GIT_REVERT_OPTIONS_INIT;
  85                 memcpy(opts, &default_opts, sizeof(git_revert_options));
  86         }
  87
  88         if (!opts->checkout_opts.checkout_strategy)
  89                 opts->checkout_opts.checkout_strategy = default_checkout_strategy;
  90
  91         if (!opts->checkout_opts.our_label)
  92                 opts->checkout_opts.our_label = "HEAD";
  93
  94         if (!opts->checkout_opts.their_label)
  95                 opts->checkout_opts.their_label = their_label;
  96
  97         return error;
  98 }
  99
 100 static int revert_state_cleanup(git_repository *repo)
 101 {
 102         const char *state_files[] = { GIT_REVERT_HEAD_FILE, GIT_MERGE_MSG_FILE };
 103
 104         return git_repository__cleanup_files(repo, state_files, ARRAY_SIZE(state_files));
 105 }
 106
 107 static int revert_seterr(git_commit *commit, const char *fmt)
 108 {
 109         char commit_oidstr[GIT_OID_HEXSZ + 1];
 110
 111         git_oid_fmt(commit_oidstr, git_commit_id(commit));
 112         commit_oidstr[GIT_OID_HEXSZ] = '\0';
 113
 114         giterr_set(GITERR_REVERT, fmt, commit_oidstr);
 115
 116         return -1;
 117 }
 118
 119 int git_revert_commit(
 120         git_index **out,
 121         git_repository *repo,
 122         git_commit *revert_commit,
 123         git_commit *our_commit,
 124         unsigned int mainline,
 125         const git_merge_options *merge_opts)
 126 {
 127         git_commit *parent_commit = NULL;
 128         git_tree *parent_tree = NULL, *our_tree = NULL, *revert_tree = NULL;
 129         int parent = 0, error = 0;
 130
 131         assert(out && repo && revert_commit && our_commit);
 132
 133         if (git_commit_parentcount(revert_commit) > 1) {
 134                 if (!mainline)
 135                         return revert_seterr(revert_commit,
 136                                 "Mainline branch is not specified but %s is a merge commit");
 137
 138                 parent = mainline;
 139         } else {
 140                 if (mainline)
 141                         return revert_seterr(revert_commit,
 142                                 "Mainline branch specified but %s is not a merge commit");
 143
 144                 parent = git_commit_parentcount(revert_commit);
 145         }
 146
 147         if (parent &&
 148                 ((error = git_commit_parent(&parent_commit, revert_commit, (parent - 1))) < 0 ||
 149                 (error = git_commit_tree(&parent_tree, parent_commit)) < 0))
 150                 goto done;
 151
 152         if ((error = git_commit_tree(&revert_tree, revert_commit)) < 0 ||
 153                 (error = git_commit_tree(&our_tree, our_commit)) < 0)
 154                 goto done;
 155
 156         error = git_merge_trees(out, repo, revert_tree, our_tree, parent_tree, merge_opts);
 157
 158 done:
 159         git_tree_free(parent_tree);
 160         git_tree_free(our_tree);
 161         git_tree_free(revert_tree);
 162         git_commit_free(parent_commit);
 163
 164         return error;
 165 }
 166
 167 int git_revert(
 168         git_repository *repo,
 169         git_commit *commit,
 170         const git_revert_options *given_opts)
 171 {
 172         git_revert_options opts;
 173         git_reference *our_ref = NULL;
 174         git_commit *our_commit = NULL;
 175         char commit_oidstr[GIT_OID_HEXSZ + 1];
 176         const char *commit_msg;
 177         git_buf their_label = GIT_BUF_INIT;
 178         git_index *index = NULL;
 179         git_indexwriter indexwriter = GIT_INDEXWRITER_INIT;
 180         int error;
 181
 182         assert(repo && commit);
 183
 184         GITERR_CHECK_VERSION(given_opts, GIT_REVERT_OPTIONS_VERSION, "git_revert_options");
 185
 186         if ((error = git_repository__ensure_not_bare(repo, "revert")) < 0)
 187                 return error;
 188
 189         git_oid_fmt(commit_oidstr, git_commit_id(commit));
 190         commit_oidstr[GIT_OID_HEXSZ] = '\0';
 191
 192         if ((commit_msg = git_commit_summary(commit)) == NULL) {
 193                 error = -1;
 194                 goto on_error;
 195         }
 196
 197         if ((error = git_buf_printf(&their_label, "parent of %.7s... %s", commit_oidstr, commit_msg)) < 0 ||
 198                 (error = revert_normalize_opts(repo, &opts, given_opts, git_buf_cstr(&their_label))) < 0 ||
 199                 (error = git_indexwriter_init_for_operation(&indexwriter, repo, &opts.checkout_opts.checkout_strategy)) < 0 ||
 200                 (error = write_revert_head(repo, commit_oidstr)) < 0 ||
 201                 (error = write_merge_msg(repo, commit_oidstr, commit_msg)) < 0 ||
 202                 (error = git_repository_head(&our_ref, repo)) < 0 ||
 203                 (error = git_reference_peel((git_object **)&our_commit, our_ref, GIT_OBJ_COMMIT)) < 0 ||
 204                 (error = git_revert_commit(&index, repo, commit, our_commit, opts.mainline, &opts.merge_opts)) < 0 ||
 205                 (error = git_merge__check_result(repo, index)) < 0 ||
 206                 (error = git_merge__append_conflicts_to_merge_msg(repo, index)) < 0 ||
 207                 (error = git_checkout_index(repo, index, &opts.checkout_opts)) < 0 ||
 208                 (error = git_indexwriter_commit(&indexwriter)) < 0)
 209                 goto on_error;
 210
 211         goto done;
 212
 213 on_error:
 214         revert_state_cleanup(repo);
 215
 216 done:
 217         git_indexwriter_cleanup(&indexwriter);
 218         git_index_free(index);
 219         git_commit_free(our_commit);
 220         git_reference_free(our_ref);
 221         git_buf_free(&their_label);
 222
 223         return error;
 224 }
 225
 226 int git_revert_init_options(git_revert_options *opts, unsigned int version)
 227 {
 228         GIT_INIT_STRUCTURE_FROM_TEMPLATE(
 229                 opts, version, git_revert_options, GIT_REVERT_OPTIONS_INIT);
 230         return 0;
 231 }