Andrew's git - gitweb.git/blob

   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
  25static 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
  32enum reset_type { MIXED, SOFT, HARD, MERGE, KEEP, NONE };
  33static const char *reset_type_names[] = {
  34        N_("mixed"), N_("soft"), N_("hard"), N_("merge"), N_("keep"), NULL
  35};
  36
  37static inline int is_merge(void)
  38{
  39        return !access(git_path("MERGE_HEAD"), F_OK);
  40}
  41
  42static 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
  94static 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.sha1, 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 += 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
 116static 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_sha1(one->sha1));
 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->sha1, 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
 145static 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        free_pathspec(&opt.pathspec);
 162
 163        return 0;
 164}
 165
 166static 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
 180static 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
 188static 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
 244static 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
 267int 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        unsigned char sha1[20];
 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", sha1);
 299        if (unborn) {
 300                /* reset on unborn branch: treat as reset to empty tree */
 301                hashcpy(sha1, EMPTY_TREE_SHA1_BIN);
 302        } else if (!pathspec.nr) {
 303                struct commit *commit;
 304                if (get_sha1_committish(rev, sha1))
 305                        die(_("Failed to resolve '%s' as a valid revision."), rev);
 306                commit = lookup_commit_reference(sha1);
 307                if (!commit)
 308                        die(_("Could not parse object '%s'."), rev);
 309                hashcpy(sha1, commit->object.sha1);
 310        } else {
 311                struct tree *tree;
 312                if (get_sha1_treeish(rev, sha1))
 313                        die(_("Failed to resolve '%s' as a valid tree."), rev);
 314                tree = parse_tree_indirect(sha1);
 315                if (!tree)
 316                        die(_("Could not parse object '%s'."), rev);
 317                hashcpy(sha1, tree->object.sha1);
 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, sha1, 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(sha1, reset_type, quiet);
 367                        if (reset_type == KEEP && !err)
 368                                err = reset_index(sha1, 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, sha1);
 381
 382                if (reset_type == HARD && !update_ref_status && !quiet)
 383                        print_new_head_line(lookup_commit_reference(sha1));
 384        }
 385        if (!pathspec.nr)
 386                remove_branch_state();
 387
 388        return update_ref_status;
 389}