builtin/reset.c

   1 /*
   2  * "git reset" builtin command
   3  *
   4  * Copyright (c) 2007 Carlos Rica
   5  *
   6  * Based on git-reset.sh, which is
   7  *
   8  * Copyright (c) 2005, 2006 Linus Torvalds and Junio C Hamano
   9  */
  10 #include "builtin.h"
  11 #include "lockfile.h"
  12 #include "tag.h"
  13 #include "object.h"
  14 #include "commit.h"
  15 #include "run-command.h"
  16 #include "refs.h"
  17 #include "diff.h"
  18 #include "diffcore.h"
  19 #include "tree.h"
  20 #include "branch.h"
  21 #include "parse-options.h"
  22 #include "unpack-trees.h"
  23 #include "cache-tree.h"
  24
  25 static const char * const git_reset_usage[] = {
  26         N_("git reset [--mixed | --soft | --hard | --merge | --keep] [-q] [<commit>]"),
  27         N_("git reset [-q] <tree-ish> [--] <paths>..."),
  28         N_("git reset --patch [<tree-ish>] [--] [<paths>...]"),
  29         NULL
  30 };
  31
  32 enum reset_type { MIXED, SOFT, HARD, MERGE, KEEP, NONE };
  33 static const char *reset_type_names[] = {
  34         N_("mixed"), N_("soft"), N_("hard"), N_("merge"), N_("keep"), NULL
  35 };
  36
  37 static inline int is_merge(void)
  38 {
  39         return !access(git_path_merge_head(), F_OK);
  40 }
  41
  42 static int reset_index(const unsigned char *sha1, int reset_type, int quiet)
  43 {
  44         int nr = 1;
  45         struct tree_desc desc[2];
  46         struct tree *tree;
  47         struct unpack_trees_options opts;
  48
  49         memset(&opts, 0, sizeof(opts));
  50         opts.head_idx = 1;
  51         opts.src_index = &the_index;
  52         opts.dst_index = &the_index;
  53         opts.fn = oneway_merge;
  54         opts.merge = 1;
  55         if (!quiet)
  56                 opts.verbose_update = 1;
  57         switch (reset_type) {
  58         case KEEP:
  59         case MERGE:
  60                 opts.update = 1;
  61                 break;
  62         case HARD:
  63                 opts.update = 1;
  64                 /* fallthrough */
  65         default:
  66                 opts.reset = 1;
  67         }
  68
  69         read_cache_unmerged();
  70
  71         if (reset_type == KEEP) {
  72                 unsigned char head_sha1[20];
  73                 if (get_sha1("HEAD", head_sha1))
  74                         return error(_("You do not have a valid HEAD."));
  75                 if (!fill_tree_descriptor(desc, head_sha1))
  76                         return error(_("Failed to find tree of HEAD."));
  77                 nr++;
  78                 opts.fn = twoway_merge;
  79         }
  80
  81         if (!fill_tree_descriptor(desc + nr - 1, sha1))
  82                 return error(_("Failed to find tree of %s."), sha1_to_hex(sha1));
  83         if (unpack_trees(nr, desc, &opts))
  84                 return -1;
  85
  86         if (reset_type == MIXED || reset_type == HARD) {
  87                 tree = parse_tree_indirect(sha1);
  88                 prime_cache_tree(&the_index, tree);
  89         }
  90
  91         return 0;
  92 }
  93
  94 static void print_new_head_line(struct commit *commit)
  95 {
  96         const char *hex, *body;
  97         const char *msg;
  98
  99         hex = find_unique_abbrev(commit->object.oid.hash, DEFAULT_ABBREV);
 100         printf(_("HEAD is now at %s"), hex);
 101         msg = logmsg_reencode(commit, NULL, get_log_output_encoding());
 102         body = strstr(msg, "\n\n");
 103         if (body) {
 104                 const char *eol;
 105                 size_t len;
 106                 body = skip_blank_lines(body + 2);
 107                 eol = strchr(body, '\n');
 108                 len = eol ? eol - body : strlen(body);
 109                 printf(" %.*s\n", (int) len, body);
 110         }
 111         else
 112                 printf("\n");
 113         unuse_commit_buffer(commit, msg);
 114 }
 115
 116 static void update_index_from_diff(struct diff_queue_struct *q,
 117                 struct diff_options *opt, void *data)
 118 {
 119         int i;
 120         int intent_to_add = *(int *)data;
 121
 122         for (i = 0; i < q->nr; i++) {
 123                 struct diff_filespec *one = q->queue[i]->one;
 124                 int is_missing = !(one->mode && !is_null_oid(&one->oid));
 125                 struct cache_entry *ce;
 126
 127                 if (is_missing && !intent_to_add) {
 128                         remove_file_from_cache(one->path);
 129                         continue;
 130                 }
 131
 132                 ce = make_cache_entry(one->mode, one->oid.hash, one->path,
 133                                       0, 0);
 134                 if (!ce)
 135                         die(_("make_cache_entry failed for path '%s'"),
 136                             one->path);
 137                 if (is_missing) {
 138                         ce->ce_flags |= CE_INTENT_TO_ADD;
 139                         set_object_name_for_intent_to_add_entry(ce);
 140                 }
 141                 add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
 142         }
 143 }
 144
 145 static int read_from_tree(const struct pathspec *pathspec,
 146                           unsigned char *tree_sha1,
 147                           int intent_to_add)
 148 {
 149         struct diff_options opt;
 150
 151         memset(&opt, 0, sizeof(opt));
 152         copy_pathspec(&opt.pathspec, pathspec);
 153         opt.output_format = DIFF_FORMAT_CALLBACK;
 154         opt.format_callback = update_index_from_diff;
 155         opt.format_callback_data = &intent_to_add;
 156
 157         if (do_diff_cache(tree_sha1, &opt))
 158                 return 1;
 159         diffcore_std(&opt);
 160         diff_flush(&opt);
 161         clear_pathspec(&opt.pathspec);
 162
 163         return 0;
 164 }
 165
 166 static void set_reflog_message(struct strbuf *sb, const char *action,
 167                                const char *rev)
 168 {
 169         const char *rla = getenv("GIT_REFLOG_ACTION");
 170
 171         strbuf_reset(sb);
 172         if (rla)
 173                 strbuf_addf(sb, "%s: %s", rla, action);
 174         else if (rev)
 175                 strbuf_addf(sb, "reset: moving to %s", rev);
 176         else
 177                 strbuf_addf(sb, "reset: %s", action);
 178 }
 179
 180 static void die_if_unmerged_cache(int reset_type)
 181 {
 182         if (is_merge() || unmerged_cache())
 183                 die(_("Cannot do a %s reset in the middle of a merge."),
 184                     _(reset_type_names[reset_type]));
 185
 186 }
 187
 188 static void parse_args(struct pathspec *pathspec,
 189                        const char **argv, const char *prefix,
 190                        int patch_mode,
 191                        const char **rev_ret)
 192 {
 193         const char *rev = "HEAD";
 194         unsigned char unused[20];
 195         /*
 196          * Possible arguments are:
 197          *
 198          * git reset [-opts] [<rev>]
 199          * git reset [-opts] <tree> [<paths>...]
 200          * git reset [-opts] <tree> -- [<paths>...]
 201          * git reset [-opts] -- [<paths>...]
 202          * git reset [-opts] <paths>...
 203          *
 204          * At this point, argv points immediately after [-opts].
 205          */
 206
 207         if (argv[0]) {
 208                 if (!strcmp(argv[0], "--")) {
 209                         argv++; /* reset to HEAD, possibly with paths */
 210                 } else if (argv[1] && !strcmp(argv[1], "--")) {
 211                         rev = argv[0];
 212                         argv += 2;
 213                 }
 214                 /*
 215                  * Otherwise, argv[0] could be either <rev> or <paths> and
 216                  * has to be unambiguous. If there is a single argument, it
 217                  * can not be a tree
 218                  */
 219                 else if ((!argv[1] && !get_sha1_committish(argv[0], unused)) ||
 220                          (argv[1] && !get_sha1_treeish(argv[0], unused))) {
 221                         /*
 222                          * Ok, argv[0] looks like a commit/tree; it should not
 223                          * be a filename.
 224                          */
 225                         verify_non_filename(prefix, argv[0]);
 226                         rev = *argv++;
 227                 } else {
 228                         /* Otherwise we treat this as a filename */
 229                         verify_filename(prefix, argv[0], 1);
 230                 }
 231         }
 232         *rev_ret = rev;
 233
 234         if (read_cache() < 0)
 235                 die(_("index file corrupt"));
 236
 237         parse_pathspec(pathspec, 0,
 238                        PATHSPEC_PREFER_FULL |
 239                        PATHSPEC_STRIP_SUBMODULE_SLASH_CHEAP |
 240                        (patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0),
 241                        prefix, argv);
 242 }
 243
 244 static int reset_refs(const char *rev, const unsigned char *sha1)
 245 {
 246         int update_ref_status;
 247         struct strbuf msg = STRBUF_INIT;
 248         unsigned char *orig = NULL, sha1_orig[20],
 249                 *old_orig = NULL, sha1_old_orig[20];
 250
 251         if (!get_sha1("ORIG_HEAD", sha1_old_orig))
 252                 old_orig = sha1_old_orig;
 253         if (!get_sha1("HEAD", sha1_orig)) {
 254                 orig = sha1_orig;
 255                 set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
 256                 update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0,
 257                            UPDATE_REFS_MSG_ON_ERR);
 258         } else if (old_orig)
 259                 delete_ref("ORIG_HEAD", old_orig, 0);
 260         set_reflog_message(&msg, "updating HEAD", rev);
 261         update_ref_status = update_ref(msg.buf, "HEAD", sha1, orig, 0,
 262                                        UPDATE_REFS_MSG_ON_ERR);
 263         strbuf_release(&msg);
 264         return update_ref_status;
 265 }
 266
 267 int cmd_reset(int argc, const char **argv, const char *prefix)
 268 {
 269         int reset_type = NONE, update_ref_status = 0, quiet = 0;
 270         int patch_mode = 0, unborn;
 271         const char *rev;
 272         struct object_id oid;
 273         struct pathspec pathspec;
 274         int intent_to_add = 0;
 275         const struct option options[] = {
 276                 OPT__QUIET(&quiet, N_("be quiet, only report errors")),
 277                 OPT_SET_INT(0, "mixed", &reset_type,
 278                                                 N_("reset HEAD and index"), MIXED),
 279                 OPT_SET_INT(0, "soft", &reset_type, N_("reset only HEAD"), SOFT),
 280                 OPT_SET_INT(0, "hard", &reset_type,
 281                                 N_("reset HEAD, index and working tree"), HARD),
 282                 OPT_SET_INT(0, "merge", &reset_type,
 283                                 N_("reset HEAD, index and working tree"), MERGE),
 284                 OPT_SET_INT(0, "keep", &reset_type,
 285                                 N_("reset HEAD but keep local changes"), KEEP),
 286                 OPT_BOOL('p', "patch", &patch_mode, N_("select hunks interactively")),
 287                 OPT_BOOL('N', "intent-to-add", &intent_to_add,
 288                                 N_("record only the fact that removed paths will be added later")),
 289                 OPT_END()
 290         };
 291
 292         git_config(git_default_config, NULL);
 293
 294         argc = parse_options(argc, argv, prefix, options, git_reset_usage,
 295                                                 PARSE_OPT_KEEP_DASHDASH);
 296         parse_args(&pathspec, argv, prefix, patch_mode, &rev);
 297
 298         unborn = !strcmp(rev, "HEAD") && get_sha1("HEAD", oid.hash);
 299         if (unborn) {
 300                 /* reset on unborn branch: treat as reset to empty tree */
 301                 hashcpy(oid.hash, EMPTY_TREE_SHA1_BIN);
 302         } else if (!pathspec.nr) {
 303                 struct commit *commit;
 304                 if (get_sha1_committish(rev, oid.hash))
 305                         die(_("Failed to resolve '%s' as a valid revision."), rev);
 306                 commit = lookup_commit_reference(oid.hash);
 307                 if (!commit)
 308                         die(_("Could not parse object '%s'."), rev);
 309                 oidcpy(&oid, &commit->object.oid);
 310         } else {
 311                 struct tree *tree;
 312                 if (get_sha1_treeish(rev, oid.hash))
 313                         die(_("Failed to resolve '%s' as a valid tree."), rev);
 314                 tree = parse_tree_indirect(oid.hash);
 315                 if (!tree)
 316                         die(_("Could not parse object '%s'."), rev);
 317                 oidcpy(&oid, &tree->object.oid);
 318         }
 319
 320         if (patch_mode) {
 321                 if (reset_type != NONE)
 322                         die(_("--patch is incompatible with --{hard,mixed,soft}"));
 323                 return run_add_interactive(rev, "--patch=reset", &pathspec);
 324         }
 325
 326         /* git reset tree [--] paths... can be used to
 327          * load chosen paths from the tree into the index without
 328          * affecting the working tree nor HEAD. */
 329         if (pathspec.nr) {
 330                 if (reset_type == MIXED)
 331                         warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
 332                 else if (reset_type != NONE)
 333                         die(_("Cannot do %s reset with paths."),
 334                                         _(reset_type_names[reset_type]));
 335         }
 336         if (reset_type == NONE)
 337                 reset_type = MIXED; /* by default */
 338
 339         if (reset_type != SOFT && (reset_type != MIXED || get_git_work_tree()))
 340                 setup_work_tree();
 341
 342         if (reset_type == MIXED && is_bare_repository())
 343                 die(_("%s reset is not allowed in a bare repository"),
 344                     _(reset_type_names[reset_type]));
 345
 346         if (intent_to_add && reset_type != MIXED)
 347                 die(_("-N can only be used with --mixed"));
 348
 349         /* Soft reset does not touch the index file nor the working tree
 350          * at all, but requires them in a good order.  Other resets reset
 351          * the index file to the tree object we are switching to. */
 352         if (reset_type == SOFT || reset_type == KEEP)
 353                 die_if_unmerged_cache(reset_type);
 354
 355         if (reset_type != SOFT) {
 356                 struct lock_file *lock = xcalloc(1, sizeof(*lock));
 357                 hold_locked_index(lock, 1);
 358                 if (reset_type == MIXED) {
 359                         int flags = quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN;
 360                         if (read_from_tree(&pathspec, oid.hash, intent_to_add))
 361                                 return 1;
 362                         if (get_git_work_tree())
 363                                 refresh_index(&the_index, flags, NULL, NULL,
 364                                               _("Unstaged changes after reset:"));
 365                 } else {
 366                         int err = reset_index(oid.hash, reset_type, quiet);
 367                         if (reset_type == KEEP && !err)
 368                                 err = reset_index(oid.hash, MIXED, quiet);
 369                         if (err)
 370                                 die(_("Could not reset index file to revision '%s'."), rev);
 371                 }
 372
 373                 if (write_locked_index(&the_index, lock, COMMIT_LOCK))
 374                         die(_("Could not write new index file."));
 375         }
 376
 377         if (!pathspec.nr && !unborn) {
 378                 /* Any resets without paths update HEAD to the head being
 379                  * switched to, saving the previous head in ORIG_HEAD before. */
 380                 update_ref_status = reset_refs(rev, oid.hash);
 381
 382                 if (reset_type == HARD && !update_ref_status && !quiet)
 383                         print_new_head_line(lookup_commit_reference(oid.hash));
 384         }
 385         if (!pathspec.nr)
 386                 remove_branch_state();
 387
 388         return update_ref_status;
 389 }