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 tree *tree;
  47        struct unpack_trees_options opts;
  48        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
  49
  50        memset(&opts, 0, sizeof(opts));
  51        opts.head_idx = 1;
  52        opts.src_index = &the_index;
  53        opts.dst_index = &the_index;
  54        opts.fn = oneway_merge;
  55        opts.merge = 1;
  56        if (!quiet)
  57                opts.verbose_update = 1;
  58        switch (reset_type) {
  59        case KEEP:
  60        case MERGE:
  61                opts.update = 1;
  62                break;
  63        case HARD:
  64                opts.update = 1;
  65                /* fallthrough */
  66        default:
  67                opts.reset = 1;
  68        }
  69
  70        newfd = hold_locked_index(lock, 1);
  71
  72        read_cache_unmerged();
  73
  74        if (reset_type == KEEP) {
  75                unsigned char head_sha1[20];
  76                if (get_sha1("HEAD", head_sha1))
  77                        return error(_("You do not have a valid HEAD."));
  78                if (!fill_tree_descriptor(desc, head_sha1))
  79                        return error(_("Failed to find tree of HEAD."));
  80                nr++;
  81                opts.fn = twoway_merge;
  82        }
  83
  84        if (!fill_tree_descriptor(desc + nr - 1, sha1))
  85                return error(_("Failed to find tree of %s."), sha1_to_hex(sha1));
  86        if (unpack_trees(nr, desc, &opts))
  87                return -1;
  88
  89        if (reset_type == MIXED || reset_type == HARD) {
  90                tree = parse_tree_indirect(sha1);
  91                prime_cache_tree(&active_cache_tree, tree);
  92        }
  93
  94        if (write_cache(newfd, active_cache, active_nr) ||
  95            commit_locked_index(lock))
  96                return error(_("Could not write new index file."));
  97
  98        return 0;
  99}
 100
 101static void print_new_head_line(struct commit *commit)
 102{
 103        const char *hex, *body;
 104
 105        hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
 106        printf(_("HEAD is now at %s"), hex);
 107        body = strstr(commit->buffer, "\n\n");
 108        if (body) {
 109                const char *eol;
 110                size_t len;
 111                body += 2;
 112                eol = strchr(body, '\n');
 113                len = eol ? eol - body : strlen(body);
 114                printf(" %.*s\n", (int) len, body);
 115        }
 116        else
 117                printf("\n");
 118}
 119
 120static int update_index_refresh(int fd, struct lock_file *index_lock, int flags)
 121{
 122        int result;
 123
 124        if (!index_lock) {
 125                index_lock = xcalloc(1, sizeof(struct lock_file));
 126                fd = hold_locked_index(index_lock, 1);
 127        }
 128
 129        if (read_cache() < 0)
 130                return error(_("Could not read index"));
 131
 132        result = refresh_index(&the_index, (flags), NULL, NULL,
 133                               _("Unstaged changes after reset:")) ? 1 : 0;
 134        if (write_cache(fd, active_cache, active_nr) ||
 135                        commit_locked_index(index_lock))
 136                return error ("Could not refresh index");
 137        return result;
 138}
 139
 140static void update_index_from_diff(struct diff_queue_struct *q,
 141                struct diff_options *opt, void *data)
 142{
 143        int i;
 144        int *discard_flag = data;
 145
 146        /* do_diff_cache() mangled the index */
 147        discard_cache();
 148        *discard_flag = 1;
 149        read_cache();
 150
 151        for (i = 0; i < q->nr; i++) {
 152                struct diff_filespec *one = q->queue[i]->one;
 153                if (one->mode && !is_null_sha1(one->sha1)) {
 154                        struct cache_entry *ce;
 155                        ce = make_cache_entry(one->mode, one->sha1, one->path,
 156                                0, 0);
 157                        if (!ce)
 158                                die(_("make_cache_entry failed for path '%s'"),
 159                                    one->path);
 160                        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
 161                                ADD_CACHE_OK_TO_REPLACE);
 162                } else
 163                        remove_file_from_cache(one->path);
 164        }
 165}
 166
 167static int interactive_reset(const char *revision, const char **argv,
 168                             const char *prefix)
 169{
 170        const char **pathspec = NULL;
 171
 172        if (*argv)
 173                pathspec = get_pathspec(prefix, argv);
 174
 175        return run_add_interactive(revision, "--patch=reset", pathspec);
 176}
 177
 178static int read_from_tree(const char *prefix, const char **argv,
 179                unsigned char *tree_sha1, int refresh_flags)
 180{
 181        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
 182        int index_fd, index_was_discarded = 0;
 183        struct diff_options opt;
 184
 185        memset(&opt, 0, sizeof(opt));
 186        diff_tree_setup_paths(get_pathspec(prefix, (const char **)argv), &opt);
 187        opt.output_format = DIFF_FORMAT_CALLBACK;
 188        opt.format_callback = update_index_from_diff;
 189        opt.format_callback_data = &index_was_discarded;
 190
 191        index_fd = hold_locked_index(lock, 1);
 192        index_was_discarded = 0;
 193        read_cache();
 194        if (do_diff_cache(tree_sha1, &opt))
 195                return 1;
 196        diffcore_std(&opt);
 197        diff_flush(&opt);
 198        diff_tree_release_paths(&opt);
 199
 200        if (!index_was_discarded)
 201                /* The index is still clobbered from do_diff_cache() */
 202                discard_cache();
 203        return update_index_refresh(index_fd, lock, refresh_flags);
 204}
 205
 206static void set_reflog_message(struct strbuf *sb, const char *action,
 207                               const char *rev)
 208{
 209        const char *rla = getenv("GIT_REFLOG_ACTION");
 210
 211        strbuf_reset(sb);
 212        if (rla)
 213                strbuf_addf(sb, "%s: %s", rla, action);
 214        else if (rev)
 215                strbuf_addf(sb, "reset: moving to %s", rev);
 216        else
 217                strbuf_addf(sb, "reset: %s", action);
 218}
 219
 220static void die_if_unmerged_cache(int reset_type)
 221{
 222        if (is_merge() || read_cache() < 0 || unmerged_cache())
 223                die(_("Cannot do a %s reset in the middle of a merge."),
 224                    _(reset_type_names[reset_type]));
 225
 226}
 227
 228int cmd_reset(int argc, const char **argv, const char *prefix)
 229{
 230        int i = 0, reset_type = NONE, update_ref_status = 0, quiet = 0;
 231        int patch_mode = 0;
 232        const char *rev = "HEAD";
 233        unsigned char sha1[20], *orig = NULL, sha1_orig[20],
 234                                *old_orig = NULL, sha1_old_orig[20];
 235        struct commit *commit;
 236        struct strbuf msg = STRBUF_INIT;
 237        const struct option options[] = {
 238                OPT__QUIET(&quiet, "be quiet, only report errors"),
 239                OPT_SET_INT(0, "mixed", &reset_type,
 240                                                "reset HEAD and index", MIXED),
 241                OPT_SET_INT(0, "soft", &reset_type, "reset only HEAD", SOFT),
 242                OPT_SET_INT(0, "hard", &reset_type,
 243                                "reset HEAD, index and working tree", HARD),
 244                OPT_SET_INT(0, "merge", &reset_type,
 245                                "reset HEAD, index and working tree", MERGE),
 246                OPT_SET_INT(0, "keep", &reset_type,
 247                                "reset HEAD but keep local changes", KEEP),
 248                OPT_BOOLEAN('p', "patch", &patch_mode, "select hunks interactively"),
 249                OPT_END()
 250        };
 251
 252        git_config(git_default_config, NULL);
 253
 254        argc = parse_options(argc, argv, prefix, options, git_reset_usage,
 255                                                PARSE_OPT_KEEP_DASHDASH);
 256
 257        /*
 258         * Possible arguments are:
 259         *
 260         * git reset [-opts] <rev> <paths>...
 261         * git reset [-opts] <rev> -- <paths>...
 262         * git reset [-opts] -- <paths>...
 263         * git reset [-opts] <paths>...
 264         *
 265         * At this point, argv[i] points immediately after [-opts].
 266         */
 267
 268        if (i < argc) {
 269                if (!strcmp(argv[i], "--")) {
 270                        i++; /* reset to HEAD, possibly with paths */
 271                } else if (i + 1 < argc && !strcmp(argv[i+1], "--")) {
 272                        rev = argv[i];
 273                        i += 2;
 274                }
 275                /*
 276                 * Otherwise, argv[i] could be either <rev> or <paths> and
 277                 * has to be unambiguous.
 278                 */
 279                else if (!get_sha1_committish(argv[i], sha1)) {
 280                        /*
 281                         * Ok, argv[i] looks like a rev; it should not
 282                         * be a filename.
 283                         */
 284                        verify_non_filename(prefix, argv[i]);
 285                        rev = argv[i++];
 286                } else {
 287                        /* Otherwise we treat this as a filename */
 288                        verify_filename(prefix, argv[i], 1);
 289                }
 290        }
 291
 292        if (get_sha1_committish(rev, sha1))
 293                die(_("Failed to resolve '%s' as a valid ref."), rev);
 294
 295        /*
 296         * NOTE: As "git reset $treeish -- $path" should be usable on
 297         * any tree-ish, this is not strictly correct. We are not
 298         * moving the HEAD to any commit; we are merely resetting the
 299         * entries in the index to that of a treeish.
 300         */
 301        commit = lookup_commit_reference(sha1);
 302        if (!commit)
 303                die(_("Could not parse object '%s'."), rev);
 304        hashcpy(sha1, commit->object.sha1);
 305
 306        if (patch_mode) {
 307                if (reset_type != NONE)
 308                        die(_("--patch is incompatible with --{hard,mixed,soft}"));
 309                return interactive_reset(rev, argv + i, prefix);
 310        }
 311
 312        /* git reset tree [--] paths... can be used to
 313         * load chosen paths from the tree into the index without
 314         * affecting the working tree nor HEAD. */
 315        if (i < argc) {
 316                if (reset_type == MIXED)
 317                        warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
 318                else if (reset_type != NONE)
 319                        die(_("Cannot do %s reset with paths."),
 320                                        _(reset_type_names[reset_type]));
 321                return read_from_tree(prefix, argv + i, sha1,
 322                                quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
 323        }
 324        if (reset_type == NONE)
 325                reset_type = MIXED; /* by default */
 326
 327        if (reset_type != SOFT && reset_type != MIXED)
 328                setup_work_tree();
 329
 330        if (reset_type == MIXED && is_bare_repository())
 331                die(_("%s reset is not allowed in a bare repository"),
 332                    _(reset_type_names[reset_type]));
 333
 334        /* Soft reset does not touch the index file nor the working tree
 335         * at all, but requires them in a good order.  Other resets reset
 336         * the index file to the tree object we are switching to. */
 337        if (reset_type == SOFT)
 338                die_if_unmerged_cache(reset_type);
 339        else {
 340                int err;
 341                if (reset_type == KEEP)
 342                        die_if_unmerged_cache(reset_type);
 343                err = reset_index_file(sha1, reset_type, quiet);
 344                if (reset_type == KEEP)
 345                        err = err || reset_index_file(sha1, MIXED, quiet);
 346                if (err)
 347                        die(_("Could not reset index file to revision '%s'."), rev);
 348        }
 349
 350        /* Any resets update HEAD to the head being switched to,
 351         * saving the previous head in ORIG_HEAD before. */
 352        if (!get_sha1("ORIG_HEAD", sha1_old_orig))
 353                old_orig = sha1_old_orig;
 354        if (!get_sha1("HEAD", sha1_orig)) {
 355                orig = sha1_orig;
 356                set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
 357                update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
 358        }
 359        else if (old_orig)
 360                delete_ref("ORIG_HEAD", old_orig, 0);
 361        set_reflog_message(&msg, "updating HEAD", rev);
 362        update_ref_status = update_ref(msg.buf, "HEAD", sha1, orig, 0, MSG_ON_ERR);
 363
 364        switch (reset_type) {
 365        case HARD:
 366                if (!update_ref_status && !quiet)
 367                        print_new_head_line(commit);
 368                break;
 369        case SOFT: /* Nothing else to do. */
 370                break;
 371        case MIXED: /* Report what has not been updated. */
 372                update_index_refresh(0, NULL,
 373                                quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN);
 374                break;
 375        }
 376
 377        remove_branch_state();
 378
 379        strbuf_release(&msg);
 380
 381        return update_ref_status;
 382}