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        N_("git reset [--mixed | --soft | --hard | --merge | --keep] [-q] [<commit>]"),
  26        N_("git reset [-q] <tree-ish> [--] <paths>..."),
  27        N_("git reset --patch [<tree-ish>] [--] [<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(const unsigned char *sha1, int reset_type, int quiet)
  42{
  43        int nr = 1;
  44        struct tree_desc desc[2];
  45        struct tree *tree;
  46        struct unpack_trees_options opts;
  47
  48        memset(&opts, 0, sizeof(opts));
  49        opts.head_idx = 1;
  50        opts.src_index = &the_index;
  51        opts.dst_index = &the_index;
  52        opts.fn = oneway_merge;
  53        opts.merge = 1;
  54        if (!quiet)
  55                opts.verbose_update = 1;
  56        switch (reset_type) {
  57        case KEEP:
  58        case MERGE:
  59                opts.update = 1;
  60                break;
  61        case HARD:
  62                opts.update = 1;
  63                /* fallthrough */
  64        default:
  65                opts.reset = 1;
  66        }
  67
  68        read_cache_unmerged();
  69
  70        if (reset_type == KEEP) {
  71                unsigned char head_sha1[20];
  72                if (get_sha1("HEAD", head_sha1))
  73                        return error(_("You do not have a valid HEAD."));
  74                if (!fill_tree_descriptor(desc, head_sha1))
  75                        return error(_("Failed to find tree of HEAD."));
  76                nr++;
  77                opts.fn = twoway_merge;
  78        }
  79
  80        if (!fill_tree_descriptor(desc + nr - 1, sha1))
  81                return error(_("Failed to find tree of %s."), sha1_to_hex(sha1));
  82        if (unpack_trees(nr, desc, &opts))
  83                return -1;
  84
  85        if (reset_type == MIXED || reset_type == HARD) {
  86                tree = parse_tree_indirect(sha1);
  87                prime_cache_tree(&active_cache_tree, tree);
  88        }
  89
  90        return 0;
  91}
  92
  93static void print_new_head_line(struct commit *commit)
  94{
  95        const char *hex, *body;
  96        char *msg;
  97
  98        hex = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
  99        printf(_("HEAD is now at %s"), hex);
 100        msg = logmsg_reencode(commit, NULL, get_log_output_encoding());
 101        body = strstr(msg, "\n\n");
 102        if (body) {
 103                const char *eol;
 104                size_t len;
 105                body += 2;
 106                eol = strchr(body, '\n');
 107                len = eol ? eol - body : strlen(body);
 108                printf(" %.*s\n", (int) len, body);
 109        }
 110        else
 111                printf("\n");
 112        logmsg_free(msg, commit);
 113}
 114
 115static void update_index_from_diff(struct diff_queue_struct *q,
 116                struct diff_options *opt, void *data)
 117{
 118        int i;
 119
 120        for (i = 0; i < q->nr; i++) {
 121                struct diff_filespec *one = q->queue[i]->one;
 122                if (one->mode && !is_null_sha1(one->sha1)) {
 123                        struct cache_entry *ce;
 124                        ce = make_cache_entry(one->mode, one->sha1, one->path,
 125                                0, 0);
 126                        if (!ce)
 127                                die(_("make_cache_entry failed for path '%s'"),
 128                                    one->path);
 129                        add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
 130                                ADD_CACHE_OK_TO_REPLACE);
 131                } else
 132                        remove_file_from_cache(one->path);
 133        }
 134}
 135
 136static int read_from_tree(const struct pathspec *pathspec,
 137                          unsigned char *tree_sha1)
 138{
 139        struct diff_options opt;
 140
 141        memset(&opt, 0, sizeof(opt));
 142        copy_pathspec(&opt.pathspec, pathspec);
 143        opt.output_format = DIFF_FORMAT_CALLBACK;
 144        opt.format_callback = update_index_from_diff;
 145
 146        read_cache();
 147        if (do_diff_cache(tree_sha1, &opt))
 148                return 1;
 149        diffcore_std(&opt);
 150        diff_flush(&opt);
 151        free_pathspec(&opt.pathspec);
 152
 153        return 0;
 154}
 155
 156static void set_reflog_message(struct strbuf *sb, const char *action,
 157                               const char *rev)
 158{
 159        const char *rla = getenv("GIT_REFLOG_ACTION");
 160
 161        strbuf_reset(sb);
 162        if (rla)
 163                strbuf_addf(sb, "%s: %s", rla, action);
 164        else if (rev)
 165                strbuf_addf(sb, "reset: moving to %s", rev);
 166        else
 167                strbuf_addf(sb, "reset: %s", action);
 168}
 169
 170static void die_if_unmerged_cache(int reset_type)
 171{
 172        if (is_merge() || read_cache() < 0 || unmerged_cache())
 173                die(_("Cannot do a %s reset in the middle of a merge."),
 174                    _(reset_type_names[reset_type]));
 175
 176}
 177
 178static void parse_args(struct pathspec *pathspec,
 179                       const char **argv, const char *prefix,
 180                       int patch_mode,
 181                       const char **rev_ret)
 182{
 183        const char *rev = "HEAD";
 184        unsigned char unused[20];
 185        /*
 186         * Possible arguments are:
 187         *
 188         * git reset [-opts] [<rev>]
 189         * git reset [-opts] <tree> [<paths>...]
 190         * git reset [-opts] <tree> -- [<paths>...]
 191         * git reset [-opts] -- [<paths>...]
 192         * git reset [-opts] <paths>...
 193         *
 194         * At this point, argv points immediately after [-opts].
 195         */
 196
 197        if (argv[0]) {
 198                if (!strcmp(argv[0], "--")) {
 199                        argv++; /* reset to HEAD, possibly with paths */
 200                } else if (argv[1] && !strcmp(argv[1], "--")) {
 201                        rev = argv[0];
 202                        argv += 2;
 203                }
 204                /*
 205                 * Otherwise, argv[0] could be either <rev> or <paths> and
 206                 * has to be unambiguous. If there is a single argument, it
 207                 * can not be a tree
 208                 */
 209                else if ((!argv[1] && !get_sha1_committish(argv[0], unused)) ||
 210                         (argv[1] && !get_sha1_treeish(argv[0], unused))) {
 211                        /*
 212                         * Ok, argv[0] looks like a commit/tree; it should not
 213                         * be a filename.
 214                         */
 215                        verify_non_filename(prefix, argv[0]);
 216                        rev = *argv++;
 217                } else {
 218                        /* Otherwise we treat this as a filename */
 219                        verify_filename(prefix, argv[0], 1);
 220                }
 221        }
 222        *rev_ret = rev;
 223        parse_pathspec(pathspec, 0,
 224                       PATHSPEC_PREFER_FULL |
 225                       (patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0),
 226                       prefix, argv);
 227}
 228
 229static int reset_refs(const char *rev, const unsigned char *sha1)
 230{
 231        int update_ref_status;
 232        struct strbuf msg = STRBUF_INIT;
 233        unsigned char *orig = NULL, sha1_orig[20],
 234                *old_orig = NULL, sha1_old_orig[20];
 235
 236        if (!get_sha1("ORIG_HEAD", sha1_old_orig))
 237                old_orig = sha1_old_orig;
 238        if (!get_sha1("HEAD", sha1_orig)) {
 239                orig = sha1_orig;
 240                set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
 241                update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
 242        } else if (old_orig)
 243                delete_ref("ORIG_HEAD", old_orig, 0);
 244        set_reflog_message(&msg, "updating HEAD", rev);
 245        update_ref_status = update_ref(msg.buf, "HEAD", sha1, orig, 0, MSG_ON_ERR);
 246        strbuf_release(&msg);
 247        return update_ref_status;
 248}
 249
 250int cmd_reset(int argc, const char **argv, const char *prefix)
 251{
 252        int reset_type = NONE, update_ref_status = 0, quiet = 0;
 253        int patch_mode = 0, unborn;
 254        const char *rev;
 255        unsigned char sha1[20];
 256        struct pathspec pathspec;
 257        const struct option options[] = {
 258                OPT__QUIET(&quiet, N_("be quiet, only report errors")),
 259                OPT_SET_INT(0, "mixed", &reset_type,
 260                                                N_("reset HEAD and index"), MIXED),
 261                OPT_SET_INT(0, "soft", &reset_type, N_("reset only HEAD"), SOFT),
 262                OPT_SET_INT(0, "hard", &reset_type,
 263                                N_("reset HEAD, index and working tree"), HARD),
 264                OPT_SET_INT(0, "merge", &reset_type,
 265                                N_("reset HEAD, index and working tree"), MERGE),
 266                OPT_SET_INT(0, "keep", &reset_type,
 267                                N_("reset HEAD but keep local changes"), KEEP),
 268                OPT_BOOL('p', "patch", &patch_mode, N_("select hunks interactively")),
 269                OPT_END()
 270        };
 271
 272        git_config(git_default_config, NULL);
 273
 274        argc = parse_options(argc, argv, prefix, options, git_reset_usage,
 275                                                PARSE_OPT_KEEP_DASHDASH);
 276        parse_args(&pathspec, argv, prefix, patch_mode, &rev);
 277
 278        unborn = !strcmp(rev, "HEAD") && get_sha1("HEAD", sha1);
 279        if (unborn) {
 280                /* reset on unborn branch: treat as reset to empty tree */
 281                hashcpy(sha1, EMPTY_TREE_SHA1_BIN);
 282        } else if (!pathspec.nr) {
 283                struct commit *commit;
 284                if (get_sha1_committish(rev, sha1))
 285                        die(_("Failed to resolve '%s' as a valid revision."), rev);
 286                commit = lookup_commit_reference(sha1);
 287                if (!commit)
 288                        die(_("Could not parse object '%s'."), rev);
 289                hashcpy(sha1, commit->object.sha1);
 290        } else {
 291                struct tree *tree;
 292                if (get_sha1_treeish(rev, sha1))
 293                        die(_("Failed to resolve '%s' as a valid tree."), rev);
 294                tree = parse_tree_indirect(sha1);
 295                if (!tree)
 296                        die(_("Could not parse object '%s'."), rev);
 297                hashcpy(sha1, tree->object.sha1);
 298        }
 299
 300        if (patch_mode) {
 301                if (reset_type != NONE)
 302                        die(_("--patch is incompatible with --{hard,mixed,soft}"));
 303                return run_add_interactive(sha1_to_hex(sha1), "--patch=reset", &pathspec);
 304        }
 305
 306        /* git reset tree [--] paths... can be used to
 307         * load chosen paths from the tree into the index without
 308         * affecting the working tree nor HEAD. */
 309        if (pathspec.nr) {
 310                if (reset_type == MIXED)
 311                        warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
 312                else if (reset_type != NONE)
 313                        die(_("Cannot do %s reset with paths."),
 314                                        _(reset_type_names[reset_type]));
 315        }
 316        if (reset_type == NONE)
 317                reset_type = MIXED; /* by default */
 318
 319        if (reset_type != SOFT && reset_type != MIXED)
 320                setup_work_tree();
 321
 322        if (reset_type == MIXED && is_bare_repository())
 323                die(_("%s reset is not allowed in a bare repository"),
 324                    _(reset_type_names[reset_type]));
 325
 326        /* Soft reset does not touch the index file nor the working tree
 327         * at all, but requires them in a good order.  Other resets reset
 328         * the index file to the tree object we are switching to. */
 329        if (reset_type == SOFT || reset_type == KEEP)
 330                die_if_unmerged_cache(reset_type);
 331
 332        if (reset_type != SOFT) {
 333                struct lock_file *lock = xcalloc(1, sizeof(*lock));
 334                int newfd = hold_locked_index(lock, 1);
 335                if (reset_type == MIXED) {
 336                        int flags = quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN;
 337                        if (read_from_tree(&pathspec, sha1))
 338                                return 1;
 339                        refresh_index(&the_index, flags, NULL, NULL,
 340                                      _("Unstaged changes after reset:"));
 341                } else {
 342                        int err = reset_index(sha1, reset_type, quiet);
 343                        if (reset_type == KEEP && !err)
 344                                err = reset_index(sha1, MIXED, quiet);
 345                        if (err)
 346                                die(_("Could not reset index file to revision '%s'."), rev);
 347                }
 348
 349                if (write_cache(newfd, active_cache, active_nr) ||
 350                    commit_locked_index(lock))
 351                        die(_("Could not write new index file."));
 352        }
 353
 354        if (!pathspec.nr && !unborn) {
 355                /* Any resets without paths update HEAD to the head being
 356                 * switched to, saving the previous head in ORIG_HEAD before. */
 357                update_ref_status = reset_refs(rev, sha1);
 358
 359                if (reset_type == HARD && !update_ref_status && !quiet)
 360                        print_new_head_line(lookup_commit_reference(sha1));
 361        }
 362        if (!pathspec.nr)
 363                remove_branch_state();
 364
 365        return update_ref_status;
 366}