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