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 "tag.h"
  12#include "object.h"
  13#include "commit.h"
  14#include "run-command.h"
  15#include "refs.h"
  16#include "diff.h"
  17#include "diffcore.h"
  18#include "tree.h"
  19#include "branch.h"
  20#include "parse-options.h"
  21#include "unpack-trees.h"
  22#include "cache-tree.h"
  23
  24static const char * const git_reset_usage[] = {
  25        "git reset [--mixed | --soft | --hard | --merge | --keep] [-q] [<commit>]",
  26        "git reset [-q] <commit> [--] <paths>...",
  27        "git reset --patch [<commit>] [--] [<paths>...]",
  28        NULL
  29};
  30
  31enum reset_type { MIXED, SOFT, HARD, MERGE, KEEP, NONE };
  32static const char *reset_type_names[] = {
  33        N_("mixed"), N_("soft"), N_("hard"), N_("merge"), N_("keep"), NULL
  34};
  35
  36static inline int is_merge(void)
  37{
  38        return !access(git_path("MERGE_HEAD"), F_OK);
  39}
  40
  41static int reset_index_file(const unsigned char *sha1, int reset_type, int quiet)
  42{
  43        int nr = 1;
  44        int newfd;
  45        struct tree_desc desc[2];
  46        struct unpack_trees_options opts;
  47        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
  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        newfd = hold_locked_index(lock, 1);
  70
  71        read_cache_unmerged();
  72
  73        if (reset_type == KEEP) {
  74                unsigned char head_sha1[20];
  75                if (get_sha1("HEAD", head_sha1))
  76                        return error(_("You do not have a valid HEAD."));
  77                if (!fill_tree_descriptor(desc, head_sha1))
  78                        return error(_("Failed to find tree of HEAD."));
  79                nr++;
  80                opts.fn = twoway_merge;
  81        }
  82
  83        if (!fill_tree_descriptor(desc + nr - 1, sha1))
  84                return error(_("Failed to find tree of %s."), sha1_to_hex(sha1));
  85        if (unpack_trees(nr, desc, &opts))
  86                return -1;
  87        if (write_cache(newfd, active_cache, active_nr) ||
  88            commit_locked_index(lock))
  89                return error(_("Could not write new index file."));
  90
  91        return 0;
  92}
  93
  94static void print_new_head_line(struct commit *commit)
  95{
  96        const char *hex, *body;
  97
  98        hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
  99        printf(_("HEAD is now at %s"), hex);
 100        body = strstr(commit->buffer, "\n\n");
 101        if (body) {
 102                const char *eol;
 103                size_t len;
 104                body += 2;
 105                eol = strchr(body, '\n');
 106                len = eol ? eol - body : strlen(body);
 107                printf(" %.*s\n", (int) len, body);
 108        }
 109        else
 110                printf("\n");
 111}
 112
 113static int update_index_refresh(int fd, struct lock_file *index_lock, int flags)
 114{
 115        int result;
 116
 117        if (!index_lock) {
 118                index_lock = xcalloc(1, sizeof(struct lock_file));
 119                fd = hold_locked_index(index_lock, 1);
 120        }
 121
 122        if (read_cache() < 0)
 123                return error(_("Could not read index"));
 124
 125        result = refresh_index(&the_index, (flags), NULL, NULL,
 126                               _("Unstaged changes after reset:")) ? 1 : 0;
 127        if (write_cache(fd, active_cache, active_nr) ||
 128                        commit_locked_index(index_lock))
 129                return error ("Could not refresh index");
 130        return result;
 131}
 132
 133static void update_index_from_diff(struct diff_queue_struct *q,
 134                struct diff_options *opt, void *data)
 135{
 136        int i;
 137        int *discard_flag = data;
 138
 139        /* do_diff_cache() mangled the index */
 140        discard_cache();
 141        *discard_flag = 1;
 142        read_cache();
 143
 144        for (i = 0; i < q->nr; i++) {
 145                struct diff_filespec *one = q->queue[i]->one;
 146                if (one->mode && !is_null_sha1(one->sha1)) {
 147                        struct cache_entry *ce;
 148                        ce = make_cache_entry(one->mode, one->sha1, one->path,
 149                                0, 0);
 150                        if (!ce)
 151                                die(_("make_cache_entry failed for path '%s'"),
 152                                    one->path);
 153                        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
 154                                ADD_CACHE_OK_TO_REPLACE);
 155                } else
 156                        remove_file_from_cache(one->path);
 157        }
 158}
 159
 160static int interactive_reset(const char *revision, const char **argv,
 161                             const char *prefix)
 162{
 163        const char **pathspec = NULL;
 164
 165        if (*argv)
 166                pathspec = get_pathspec(prefix, argv);
 167
 168        return run_add_interactive(revision, "--patch=reset", pathspec);
 169}
 170
 171static int read_from_tree(const char *prefix, const char **argv,
 172                unsigned char *tree_sha1, int refresh_flags)
 173{
 174        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
 175        int index_fd, index_was_discarded = 0;
 176        struct diff_options opt;
 177
 178        memset(&opt, 0, sizeof(opt));
 179        diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
 180        opt.output_format = DIFF_FORMAT_CALLBACK;
 181        opt.format_callback = update_index_from_diff;
 182        opt.format_callback_data = &index_was_discarded;
 183
 184        index_fd = hold_locked_index(lock, 1);
 185        index_was_discarded = 0;
 186        read_cache();
 187        if (do_diff_cache(tree_sha1, &opt))
 188                return 1;
 189        diffcore_std(&opt);
 190        diff_flush(&opt);
 191        diff_tree_release_paths(&opt);
 192
 193        if (!index_was_discarded)
 194                /* The index is still clobbered from do_diff_cache() */
 195                discard_cache();
 196        return update_index_refresh(index_fd, lock, refresh_flags);
 197}
 198
 199static void set_reflog_message(struct strbuf *sb, const char *action,
 200                               const char *rev)
 201{
 202        const char *rla = getenv("GIT_REFLOG_ACTION");
 203
 204        strbuf_reset(sb);
 205        if (rla)
 206                strbuf_addf(sb, "%s: %s", rla, action);
 207        else if (rev)
 208                strbuf_addf(sb, "reset: moving to %s", rev);
 209        else
 210                strbuf_addf(sb, "reset: %s", action);
 211}
 212
 213static void die_if_unmerged_cache(int reset_type)
 214{
 215        if (is_merge() || read_cache() < 0 || unmerged_cache())
 216                die(_("Cannot do a %s reset in the middle of a merge."),
 217                    _(reset_type_names[reset_type]));
 218
 219}
 220
 221int cmd_reset(int argc, const char **argv, const char *prefix)
 222{
 223        int i = 0, reset_type = NONE, update_ref_status = 0, quiet = 0;
 224        int patch_mode = 0;
 225        const char *rev = "HEAD";
 226        unsigned char sha1[20], *orig = NULL, sha1_orig[20],
 227                                *old_orig = NULL, sha1_old_orig[20];
 228        struct commit *commit;
 229        struct strbuf msg = STRBUF_INIT;
 230        const struct option options[] = {
 231                OPT__QUIET(&quiet, "be quiet, only report errors"),
 232                OPT_SET_INT(0, "mixed", &reset_type,
 233                                                "reset HEAD and index", MIXED),
 234                OPT_SET_INT(0, "soft", &reset_type, "reset only HEAD", SOFT),
 235                OPT_SET_INT(0, "hard", &reset_type,
 236                                "reset HEAD, index and working tree", HARD),
 237                OPT_SET_INT(0, "merge", &reset_type,
 238                                "reset HEAD, index and working tree", MERGE),
 239                OPT_SET_INT(0, "keep", &reset_type,
 240                                "reset HEAD but keep local changes", KEEP),
 241                OPT_BOOLEAN('p', "patch", &patch_mode, "select hunks interactively"),
 242                OPT_END()
 243        };
 244
 245        git_config(git_default_config, NULL);
 246
 247        argc = parse_options(argc, argv, prefix, options, git_reset_usage,
 248                                                PARSE_OPT_KEEP_DASHDASH);
 249
 250        /*
 251         * Possible arguments are:
 252         *
 253         * git reset [-opts] <rev> <paths>...
 254         * git reset [-opts] <rev> -- <paths>...
 255         * git reset [-opts] -- <paths>...
 256         * git reset [-opts] <paths>...
 257         *
 258         * At this point, argv[i] points immediately after [-opts].
 259         */
 260
 261        if (i < argc) {
 262                if (!strcmp(argv[i], "--")) {
 263                        i++; /* reset to HEAD, possibly with paths */
 264                } else if (i + 1 < argc && !strcmp(argv[i+1], "--")) {
 265                        rev = argv[i];
 266                        i += 2;
 267                }
 268                /*
 269                 * Otherwise, argv[i] could be either <rev> or <paths> and
 270                 * has to be unambiguous.
 271                 */
 272                else if (!get_sha1(argv[i], sha1)) {
 273                        /*
 274                         * Ok, argv[i] looks like a rev; it should not
 275                         * be a filename.
 276                         */
 277                        verify_non_filename(prefix, argv[i]);
 278                        rev = argv[i++];
 279                } else {
 280                        /* Otherwise we treat this as a filename */
 281                        verify_filename(prefix, argv[i]);
 282                }
 283        }
 284
 285        if (get_sha1(rev, sha1))
 286                die(_("Failed to resolve '%s' as a valid ref."), rev);
 287
 288        commit = lookup_commit_reference(sha1);
 289        if (!commit)
 290                die(_("Could not parse object '%s'."), rev);
 291        hashcpy(sha1, commit->object.sha1);
 292
 293        if (patch_mode) {
 294                if (reset_type != NONE)
 295                        die(_("--patch is incompatible with --{hard,mixed,soft}"));
 296                return interactive_reset(rev, argv + i, prefix);
 297        }
 298
 299        /* git reset tree [--] paths... can be used to
 300         * load chosen paths from the tree into the index without
 301         * affecting the working tree nor HEAD. */
 302        if (i < argc) {
 303                if (reset_type == MIXED)
 304                        warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
 305                else if (reset_type != NONE)
 306                        die(_("Cannot do %s reset with paths."),
 307                                        _(reset_type_names[reset_type]));
 308                return read_from_tree(prefix, argv + i, sha1,
 309                                quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
 310        }
 311        if (reset_type == NONE)
 312                reset_type = MIXED; /* by default */
 313
 314        if (reset_type != SOFT && reset_type != MIXED)
 315                setup_work_tree();
 316
 317        if (reset_type == MIXED && is_bare_repository())
 318                die(_("%s reset is not allowed in a bare repository"),
 319                    _(reset_type_names[reset_type]));
 320
 321        /* Soft reset does not touch the index file nor the working tree
 322         * at all, but requires them in a good order.  Other resets reset
 323         * the index file to the tree object we are switching to. */
 324        if (reset_type == SOFT)
 325                die_if_unmerged_cache(reset_type);
 326        else {
 327                int err;
 328                if (reset_type == KEEP)
 329                        die_if_unmerged_cache(reset_type);
 330                err = reset_index_file(sha1, reset_type, quiet);
 331                if (reset_type == KEEP)
 332                        err = err || reset_index_file(sha1, MIXED, quiet);
 333                if (err)
 334                        die(_("Could not reset index file to revision '%s'."), rev);
 335        }
 336
 337        /* Any resets update HEAD to the head being switched to,
 338         * saving the previous head in ORIG_HEAD before. */
 339        if (!get_sha1("ORIG_HEAD", sha1_old_orig))
 340                old_orig = sha1_old_orig;
 341        if (!get_sha1("HEAD", sha1_orig)) {
 342                orig = sha1_orig;
 343                set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
 344                update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
 345        }
 346        else if (old_orig)
 347                delete_ref("ORIG_HEAD", old_orig, 0);
 348        set_reflog_message(&msg, "updating HEAD", rev);
 349        update_ref_status = update_ref(msg.buf, "HEAD", sha1, orig, 0, MSG_ON_ERR);
 350
 351        switch (reset_type) {
 352        case HARD:
 353                if (!update_ref_status && !quiet)
 354                        print_new_head_line(commit);
 355                break;
 356        case SOFT: /* Nothing else to do. */
 357                break;
 358        case MIXED: /* Report what has not been updated. */
 359                update_index_refresh(0, NULL,
 360                                quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
 361                break;
 362        }
 363
 364        remove_branch_state();
 365
 366        strbuf_release(&msg);
 367
 368        return update_ref_status;
 369}