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        if (do_diff_cache(tree_sha1, &opt))
 147                return 1;
 148        diffcore_std(&opt);
 149        diff_flush(&opt);
 150        free_pathspec(&opt.pathspec);
 151
 152        return 0;
 153}
 154
 155static void set_reflog_message(struct strbuf *sb, const char *action,
 156                               const char *rev)
 157{
 158        const char *rla = getenv("GIT_REFLOG_ACTION");
 159
 160        strbuf_reset(sb);
 161        if (rla)
 162                strbuf_addf(sb, "%s: %s", rla, action);
 163        else if (rev)
 164                strbuf_addf(sb, "reset: moving to %s", rev);
 165        else
 166                strbuf_addf(sb, "reset: %s", action);
 167}
 168
 169static void die_if_unmerged_cache(int reset_type)
 170{
 171        if (is_merge() || unmerged_cache())
 172                die(_("Cannot do a %s reset in the middle of a merge."),
 173                    _(reset_type_names[reset_type]));
 174
 175}
 176
 177static void parse_args(struct pathspec *pathspec,
 178                       const char **argv, const char *prefix,
 179                       int patch_mode,
 180                       const char **rev_ret)
 181{
 182        const char *rev = "HEAD";
 183        unsigned char unused[20];
 184        /*
 185         * Possible arguments are:
 186         *
 187         * git reset [-opts] [<rev>]
 188         * git reset [-opts] <tree> [<paths>...]
 189         * git reset [-opts] <tree> -- [<paths>...]
 190         * git reset [-opts] -- [<paths>...]
 191         * git reset [-opts] <paths>...
 192         *
 193         * At this point, argv points immediately after [-opts].
 194         */
 195
 196        if (argv[0]) {
 197                if (!strcmp(argv[0], "--")) {
 198                        argv++; /* reset to HEAD, possibly with paths */
 199                } else if (argv[1] && !strcmp(argv[1], "--")) {
 200                        rev = argv[0];
 201                        argv += 2;
 202                }
 203                /*
 204                 * Otherwise, argv[0] could be either <rev> or <paths> and
 205                 * has to be unambiguous. If there is a single argument, it
 206                 * can not be a tree
 207                 */
 208                else if ((!argv[1] && !get_sha1_committish(argv[0], unused)) ||
 209                         (argv[1] && !get_sha1_treeish(argv[0], unused))) {
 210                        /*
 211                         * Ok, argv[0] looks like a commit/tree; it should not
 212                         * be a filename.
 213                         */
 214                        verify_non_filename(prefix, argv[0]);
 215                        rev = *argv++;
 216                } else {
 217                        /* Otherwise we treat this as a filename */
 218                        verify_filename(prefix, argv[0], 1);
 219                }
 220        }
 221        *rev_ret = rev;
 222
 223        if (read_cache() < 0)
 224                die(_("index file corrupt"));
 225
 226        parse_pathspec(pathspec, 0,
 227                       PATHSPEC_PREFER_FULL |
 228                       PATHSPEC_STRIP_SUBMODULE_SLASH_CHEAP |
 229                       (patch_mode ? PATHSPEC_PREFIX_ORIGIN : 0),
 230                       prefix, argv);
 231}
 232
 233static int reset_refs(const char *rev, const unsigned char *sha1)
 234{
 235        int update_ref_status;
 236        struct strbuf msg = STRBUF_INIT;
 237        unsigned char *orig = NULL, sha1_orig[20],
 238                *old_orig = NULL, sha1_old_orig[20];
 239
 240        if (!get_sha1("ORIG_HEAD", sha1_old_orig))
 241                old_orig = sha1_old_orig;
 242        if (!get_sha1("HEAD", sha1_orig)) {
 243                orig = sha1_orig;
 244                set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
 245                update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
 246        } else if (old_orig)
 247                delete_ref("ORIG_HEAD", old_orig, 0);
 248        set_reflog_message(&msg, "updating HEAD", rev);
 249        update_ref_status = update_ref(msg.buf, "HEAD", sha1, orig, 0, MSG_ON_ERR);
 250        strbuf_release(&msg);
 251        return update_ref_status;
 252}
 253
 254int cmd_reset(int argc, const char **argv, const char *prefix)
 255{
 256        int reset_type = NONE, update_ref_status = 0, quiet = 0;
 257        int patch_mode = 0, unborn;
 258        const char *rev;
 259        unsigned char sha1[20];
 260        struct pathspec pathspec;
 261        const struct option options[] = {
 262                OPT__QUIET(&quiet, N_("be quiet, only report errors")),
 263                OPT_SET_INT(0, "mixed", &reset_type,
 264                                                N_("reset HEAD and index"), MIXED),
 265                OPT_SET_INT(0, "soft", &reset_type, N_("reset only HEAD"), SOFT),
 266                OPT_SET_INT(0, "hard", &reset_type,
 267                                N_("reset HEAD, index and working tree"), HARD),
 268                OPT_SET_INT(0, "merge", &reset_type,
 269                                N_("reset HEAD, index and working tree"), MERGE),
 270                OPT_SET_INT(0, "keep", &reset_type,
 271                                N_("reset HEAD but keep local changes"), KEEP),
 272                OPT_BOOL('p', "patch", &patch_mode, N_("select hunks interactively")),
 273                OPT_END()
 274        };
 275
 276        git_config(git_default_config, NULL);
 277
 278        argc = parse_options(argc, argv, prefix, options, git_reset_usage,
 279                                                PARSE_OPT_KEEP_DASHDASH);
 280        parse_args(&pathspec, argv, prefix, patch_mode, &rev);
 281
 282        unborn = !strcmp(rev, "HEAD") && get_sha1("HEAD", sha1);
 283        if (unborn) {
 284                /* reset on unborn branch: treat as reset to empty tree */
 285                hashcpy(sha1, EMPTY_TREE_SHA1_BIN);
 286        } else if (!pathspec.nr) {
 287                struct commit *commit;
 288                if (get_sha1_committish(rev, sha1))
 289                        die(_("Failed to resolve '%s' as a valid revision."), rev);
 290                commit = lookup_commit_reference(sha1);
 291                if (!commit)
 292                        die(_("Could not parse object '%s'."), rev);
 293                hashcpy(sha1, commit->object.sha1);
 294        } else {
 295                struct tree *tree;
 296                if (get_sha1_treeish(rev, sha1))
 297                        die(_("Failed to resolve '%s' as a valid tree."), rev);
 298                tree = parse_tree_indirect(sha1);
 299                if (!tree)
 300                        die(_("Could not parse object '%s'."), rev);
 301                hashcpy(sha1, tree->object.sha1);
 302        }
 303
 304        if (patch_mode) {
 305                if (reset_type != NONE)
 306                        die(_("--patch is incompatible with --{hard,mixed,soft}"));
 307                return run_add_interactive(rev, "--patch=reset", &pathspec);
 308        }
 309
 310        /* git reset tree [--] paths... can be used to
 311         * load chosen paths from the tree into the index without
 312         * affecting the working tree nor HEAD. */
 313        if (pathspec.nr) {
 314                if (reset_type == MIXED)
 315                        warning(_("--mixed with paths is deprecated; use 'git reset -- <paths>' instead."));
 316                else if (reset_type != NONE)
 317                        die(_("Cannot do %s reset with paths."),
 318                                        _(reset_type_names[reset_type]));
 319        }
 320        if (reset_type == NONE)
 321                reset_type = MIXED; /* by default */
 322
 323        if (reset_type != SOFT && reset_type != MIXED)
 324                setup_work_tree();
 325
 326        if (reset_type == MIXED && is_bare_repository())
 327                die(_("%s reset is not allowed in a bare repository"),
 328                    _(reset_type_names[reset_type]));
 329
 330        /* Soft reset does not touch the index file nor the working tree
 331         * at all, but requires them in a good order.  Other resets reset
 332         * the index file to the tree object we are switching to. */
 333        if (reset_type == SOFT || reset_type == KEEP)
 334                die_if_unmerged_cache(reset_type);
 335
 336        if (reset_type != SOFT) {
 337                struct lock_file *lock = xcalloc(1, sizeof(*lock));
 338                int newfd = hold_locked_index(lock, 1);
 339                if (reset_type == MIXED) {
 340                        int flags = quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN;
 341                        if (read_from_tree(&pathspec, sha1))
 342                                return 1;
 343                        refresh_index(&the_index, flags, NULL, NULL,
 344                                      _("Unstaged changes after reset:"));
 345                } else {
 346                        int err = reset_index(sha1, reset_type, quiet);
 347                        if (reset_type == KEEP && !err)
 348                                err = reset_index(sha1, MIXED, quiet);
 349                        if (err)
 350                                die(_("Could not reset index file to revision '%s'."), rev);
 351                }
 352
 353                if (write_cache(newfd, active_cache, active_nr) ||
 354                    commit_locked_index(lock))
 355                        die(_("Could not write new index file."));
 356        }
 357
 358        if (!pathspec.nr && !unborn) {
 359                /* Any resets without paths update HEAD to the head being
 360                 * switched to, saving the previous head in ORIG_HEAD before. */
 361                update_ref_status = reset_refs(rev, sha1);
 362
 363                if (reset_type == HARD && !update_ref_status && !quiet)
 364                        print_new_head_line(lookup_commit_reference(sha1));
 365        }
 366        if (!pathspec.nr)
 367                remove_branch_state();
 368
 369        return update_ref_status;
 370}