sha1_name.con commit Merge branch 'nd/gitignore-trailing-whitespace' into maint (7fa1365)
   1#include "cache.h"
   2#include "tag.h"
   3#include "commit.h"
   4#include "tree.h"
   5#include "blob.h"
   6#include "tree-walk.h"
   7#include "refs.h"
   8#include "remote.h"
   9
  10static int get_sha1_oneline(const char *, unsigned char *, struct commit_list *);
  11
  12typedef int (*disambiguate_hint_fn)(const unsigned char *, void *);
  13
  14struct disambiguate_state {
  15        disambiguate_hint_fn fn;
  16        void *cb_data;
  17        unsigned char candidate[20];
  18        unsigned candidate_exists:1;
  19        unsigned candidate_checked:1;
  20        unsigned candidate_ok:1;
  21        unsigned disambiguate_fn_used:1;
  22        unsigned ambiguous:1;
  23        unsigned always_call_fn:1;
  24};
  25
  26static void update_candidates(struct disambiguate_state *ds, const unsigned char *current)
  27{
  28        if (ds->always_call_fn) {
  29                ds->ambiguous = ds->fn(current, ds->cb_data) ? 1 : 0;
  30                return;
  31        }
  32        if (!ds->candidate_exists) {
  33                /* this is the first candidate */
  34                hashcpy(ds->candidate, current);
  35                ds->candidate_exists = 1;
  36                return;
  37        } else if (!hashcmp(ds->candidate, current)) {
  38                /* the same as what we already have seen */
  39                return;
  40        }
  41
  42        if (!ds->fn) {
  43                /* cannot disambiguate between ds->candidate and current */
  44                ds->ambiguous = 1;
  45                return;
  46        }
  47
  48        if (!ds->candidate_checked) {
  49                ds->candidate_ok = ds->fn(ds->candidate, ds->cb_data);
  50                ds->disambiguate_fn_used = 1;
  51                ds->candidate_checked = 1;
  52        }
  53
  54        if (!ds->candidate_ok) {
  55                /* discard the candidate; we know it does not satisfy fn */
  56                hashcpy(ds->candidate, current);
  57                ds->candidate_checked = 0;
  58                return;
  59        }
  60
  61        /* if we reach this point, we know ds->candidate satisfies fn */
  62        if (ds->fn(current, ds->cb_data)) {
  63                /*
  64                 * if both current and candidate satisfy fn, we cannot
  65                 * disambiguate.
  66                 */
  67                ds->candidate_ok = 0;
  68                ds->ambiguous = 1;
  69        }
  70
  71        /* otherwise, current can be discarded and candidate is still good */
  72}
  73
  74static void find_short_object_filename(int len, const char *hex_pfx, struct disambiguate_state *ds)
  75{
  76        struct alternate_object_database *alt;
  77        char hex[40];
  78        static struct alternate_object_database *fakeent;
  79
  80        if (!fakeent) {
  81                /*
  82                 * Create a "fake" alternate object database that
  83                 * points to our own object database, to make it
  84                 * easier to get a temporary working space in
  85                 * alt->name/alt->base while iterating over the
  86                 * object databases including our own.
  87                 */
  88                const char *objdir = get_object_directory();
  89                int objdir_len = strlen(objdir);
  90                int entlen = objdir_len + 43;
  91                fakeent = xmalloc(sizeof(*fakeent) + entlen);
  92                memcpy(fakeent->base, objdir, objdir_len);
  93                fakeent->name = fakeent->base + objdir_len + 1;
  94                fakeent->name[-1] = '/';
  95        }
  96        fakeent->next = alt_odb_list;
  97
  98        sprintf(hex, "%.2s", hex_pfx);
  99        for (alt = fakeent; alt && !ds->ambiguous; alt = alt->next) {
 100                struct dirent *de;
 101                DIR *dir;
 102                sprintf(alt->name, "%.2s/", hex_pfx);
 103                dir = opendir(alt->base);
 104                if (!dir)
 105                        continue;
 106
 107                while (!ds->ambiguous && (de = readdir(dir)) != NULL) {
 108                        unsigned char sha1[20];
 109
 110                        if (strlen(de->d_name) != 38)
 111                                continue;
 112                        if (memcmp(de->d_name, hex_pfx + 2, len - 2))
 113                                continue;
 114                        memcpy(hex + 2, de->d_name, 38);
 115                        if (!get_sha1_hex(hex, sha1))
 116                                update_candidates(ds, sha1);
 117                }
 118                closedir(dir);
 119        }
 120}
 121
 122static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
 123{
 124        do {
 125                if (*a != *b)
 126                        return 0;
 127                a++;
 128                b++;
 129                len -= 2;
 130        } while (len > 1);
 131        if (len)
 132                if ((*a ^ *b) & 0xf0)
 133                        return 0;
 134        return 1;
 135}
 136
 137static void unique_in_pack(int len,
 138                          const unsigned char *bin_pfx,
 139                           struct packed_git *p,
 140                           struct disambiguate_state *ds)
 141{
 142        uint32_t num, last, i, first = 0;
 143        const unsigned char *current = NULL;
 144
 145        open_pack_index(p);
 146        num = p->num_objects;
 147        last = num;
 148        while (first < last) {
 149                uint32_t mid = (first + last) / 2;
 150                const unsigned char *current;
 151                int cmp;
 152
 153                current = nth_packed_object_sha1(p, mid);
 154                cmp = hashcmp(bin_pfx, current);
 155                if (!cmp) {
 156                        first = mid;
 157                        break;
 158                }
 159                if (cmp > 0) {
 160                        first = mid+1;
 161                        continue;
 162                }
 163                last = mid;
 164        }
 165
 166        /*
 167         * At this point, "first" is the location of the lowest object
 168         * with an object name that could match "bin_pfx".  See if we have
 169         * 0, 1 or more objects that actually match(es).
 170         */
 171        for (i = first; i < num && !ds->ambiguous; i++) {
 172                current = nth_packed_object_sha1(p, i);
 173                if (!match_sha(len, bin_pfx, current))
 174                        break;
 175                update_candidates(ds, current);
 176        }
 177}
 178
 179static void find_short_packed_object(int len, const unsigned char *bin_pfx,
 180                                     struct disambiguate_state *ds)
 181{
 182        struct packed_git *p;
 183
 184        prepare_packed_git();
 185        for (p = packed_git; p && !ds->ambiguous; p = p->next)
 186                unique_in_pack(len, bin_pfx, p, ds);
 187}
 188
 189#define SHORT_NAME_NOT_FOUND (-1)
 190#define SHORT_NAME_AMBIGUOUS (-2)
 191
 192static int finish_object_disambiguation(struct disambiguate_state *ds,
 193                                        unsigned char *sha1)
 194{
 195        if (ds->ambiguous)
 196                return SHORT_NAME_AMBIGUOUS;
 197
 198        if (!ds->candidate_exists)
 199                return SHORT_NAME_NOT_FOUND;
 200
 201        if (!ds->candidate_checked)
 202                /*
 203                 * If this is the only candidate, there is no point
 204                 * calling the disambiguation hint callback.
 205                 *
 206                 * On the other hand, if the current candidate
 207                 * replaced an earlier candidate that did _not_ pass
 208                 * the disambiguation hint callback, then we do have
 209                 * more than one objects that match the short name
 210                 * given, so we should make sure this one matches;
 211                 * otherwise, if we discovered this one and the one
 212                 * that we previously discarded in the reverse order,
 213                 * we would end up showing different results in the
 214                 * same repository!
 215                 */
 216                ds->candidate_ok = (!ds->disambiguate_fn_used ||
 217                                    ds->fn(ds->candidate, ds->cb_data));
 218
 219        if (!ds->candidate_ok)
 220                return SHORT_NAME_AMBIGUOUS;
 221
 222        hashcpy(sha1, ds->candidate);
 223        return 0;
 224}
 225
 226static int disambiguate_commit_only(const unsigned char *sha1, void *cb_data_unused)
 227{
 228        int kind = sha1_object_info(sha1, NULL);
 229        return kind == OBJ_COMMIT;
 230}
 231
 232static int disambiguate_committish_only(const unsigned char *sha1, void *cb_data_unused)
 233{
 234        struct object *obj;
 235        int kind;
 236
 237        kind = sha1_object_info(sha1, NULL);
 238        if (kind == OBJ_COMMIT)
 239                return 1;
 240        if (kind != OBJ_TAG)
 241                return 0;
 242
 243        /* We need to do this the hard way... */
 244        obj = deref_tag(parse_object(sha1), NULL, 0);
 245        if (obj && obj->type == OBJ_COMMIT)
 246                return 1;
 247        return 0;
 248}
 249
 250static int disambiguate_tree_only(const unsigned char *sha1, void *cb_data_unused)
 251{
 252        int kind = sha1_object_info(sha1, NULL);
 253        return kind == OBJ_TREE;
 254}
 255
 256static int disambiguate_treeish_only(const unsigned char *sha1, void *cb_data_unused)
 257{
 258        struct object *obj;
 259        int kind;
 260
 261        kind = sha1_object_info(sha1, NULL);
 262        if (kind == OBJ_TREE || kind == OBJ_COMMIT)
 263                return 1;
 264        if (kind != OBJ_TAG)
 265                return 0;
 266
 267        /* We need to do this the hard way... */
 268        obj = deref_tag(lookup_object(sha1), NULL, 0);
 269        if (obj && (obj->type == OBJ_TREE || obj->type == OBJ_COMMIT))
 270                return 1;
 271        return 0;
 272}
 273
 274static int disambiguate_blob_only(const unsigned char *sha1, void *cb_data_unused)
 275{
 276        int kind = sha1_object_info(sha1, NULL);
 277        return kind == OBJ_BLOB;
 278}
 279
 280static int prepare_prefixes(const char *name, int len,
 281                            unsigned char *bin_pfx,
 282                            char *hex_pfx)
 283{
 284        int i;
 285
 286        hashclr(bin_pfx);
 287        memset(hex_pfx, 'x', 40);
 288        for (i = 0; i < len ;i++) {
 289                unsigned char c = name[i];
 290                unsigned char val;
 291                if (c >= '0' && c <= '9')
 292                        val = c - '0';
 293                else if (c >= 'a' && c <= 'f')
 294                        val = c - 'a' + 10;
 295                else if (c >= 'A' && c <='F') {
 296                        val = c - 'A' + 10;
 297                        c -= 'A' - 'a';
 298                }
 299                else
 300                        return -1;
 301                hex_pfx[i] = c;
 302                if (!(i & 1))
 303                        val <<= 4;
 304                bin_pfx[i >> 1] |= val;
 305        }
 306        return 0;
 307}
 308
 309static int get_short_sha1(const char *name, int len, unsigned char *sha1,
 310                          unsigned flags)
 311{
 312        int status;
 313        char hex_pfx[40];
 314        unsigned char bin_pfx[20];
 315        struct disambiguate_state ds;
 316        int quietly = !!(flags & GET_SHA1_QUIETLY);
 317
 318        if (len < MINIMUM_ABBREV || len > 40)
 319                return -1;
 320        if (prepare_prefixes(name, len, bin_pfx, hex_pfx) < 0)
 321                return -1;
 322
 323        prepare_alt_odb();
 324
 325        memset(&ds, 0, sizeof(ds));
 326        if (flags & GET_SHA1_COMMIT)
 327                ds.fn = disambiguate_commit_only;
 328        else if (flags & GET_SHA1_COMMITTISH)
 329                ds.fn = disambiguate_committish_only;
 330        else if (flags & GET_SHA1_TREE)
 331                ds.fn = disambiguate_tree_only;
 332        else if (flags & GET_SHA1_TREEISH)
 333                ds.fn = disambiguate_treeish_only;
 334        else if (flags & GET_SHA1_BLOB)
 335                ds.fn = disambiguate_blob_only;
 336
 337        find_short_object_filename(len, hex_pfx, &ds);
 338        find_short_packed_object(len, bin_pfx, &ds);
 339        status = finish_object_disambiguation(&ds, sha1);
 340
 341        if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
 342                return error("short SHA1 %.*s is ambiguous.", len, hex_pfx);
 343        return status;
 344}
 345
 346int for_each_abbrev(const char *prefix, each_abbrev_fn fn, void *cb_data)
 347{
 348        char hex_pfx[40];
 349        unsigned char bin_pfx[20];
 350        struct disambiguate_state ds;
 351        int len = strlen(prefix);
 352
 353        if (len < MINIMUM_ABBREV || len > 40)
 354                return -1;
 355        if (prepare_prefixes(prefix, len, bin_pfx, hex_pfx) < 0)
 356                return -1;
 357
 358        prepare_alt_odb();
 359
 360        memset(&ds, 0, sizeof(ds));
 361        ds.always_call_fn = 1;
 362        ds.cb_data = cb_data;
 363        ds.fn = fn;
 364
 365        find_short_object_filename(len, hex_pfx, &ds);
 366        find_short_packed_object(len, bin_pfx, &ds);
 367        return ds.ambiguous;
 368}
 369
 370const char *find_unique_abbrev(const unsigned char *sha1, int len)
 371{
 372        int status, exists;
 373        static char hex[41];
 374
 375        exists = has_sha1_file(sha1);
 376        memcpy(hex, sha1_to_hex(sha1), 40);
 377        if (len == 40 || !len)
 378                return hex;
 379        while (len < 40) {
 380                unsigned char sha1_ret[20];
 381                status = get_short_sha1(hex, len, sha1_ret, GET_SHA1_QUIETLY);
 382                if (exists
 383                    ? !status
 384                    : status == SHORT_NAME_NOT_FOUND) {
 385                        hex[len] = 0;
 386                        return hex;
 387                }
 388                len++;
 389        }
 390        return hex;
 391}
 392
 393static int ambiguous_path(const char *path, int len)
 394{
 395        int slash = 1;
 396        int cnt;
 397
 398        for (cnt = 0; cnt < len; cnt++) {
 399                switch (*path++) {
 400                case '\0':
 401                        break;
 402                case '/':
 403                        if (slash)
 404                                break;
 405                        slash = 1;
 406                        continue;
 407                case '.':
 408                        continue;
 409                default:
 410                        slash = 0;
 411                        continue;
 412                }
 413                break;
 414        }
 415        return slash;
 416}
 417
 418static inline int upstream_mark(const char *string, int len)
 419{
 420        const char *suffix[] = { "@{upstream}", "@{u}" };
 421        int i;
 422
 423        for (i = 0; i < ARRAY_SIZE(suffix); i++) {
 424                int suffix_len = strlen(suffix[i]);
 425                if (suffix_len <= len
 426                    && !memcmp(string, suffix[i], suffix_len))
 427                        return suffix_len;
 428        }
 429        return 0;
 430}
 431
 432static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags);
 433static int interpret_nth_prior_checkout(const char *name, int namelen, struct strbuf *buf);
 434
 435static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 436{
 437        static const char *warn_msg = "refname '%.*s' is ambiguous.";
 438        static const char *object_name_msg = N_(
 439        "Git normally never creates a ref that ends with 40 hex characters\n"
 440        "because it will be ignored when you just specify 40-hex. These refs\n"
 441        "may be created by mistake. For example,\n"
 442        "\n"
 443        "  git checkout -b $br $(git rev-parse ...)\n"
 444        "\n"
 445        "where \"$br\" is somehow empty and a 40-hex ref is created. Please\n"
 446        "examine these refs and maybe delete them. Turn this message off by\n"
 447        "running \"git config advice.objectNameWarning false\"");
 448        unsigned char tmp_sha1[20];
 449        char *real_ref = NULL;
 450        int refs_found = 0;
 451        int at, reflog_len, nth_prior = 0;
 452
 453        if (len == 40 && !get_sha1_hex(str, sha1)) {
 454                if (warn_ambiguous_refs && warn_on_object_refname_ambiguity) {
 455                        refs_found = dwim_ref(str, len, tmp_sha1, &real_ref);
 456                        if (refs_found > 0) {
 457                                warning(warn_msg, len, str);
 458                                if (advice_object_name_warning)
 459                                        fprintf(stderr, "%s\n", _(object_name_msg));
 460                        }
 461                        free(real_ref);
 462                }
 463                return 0;
 464        }
 465
 466        /* basic@{time or number or -number} format to query ref-log */
 467        reflog_len = at = 0;
 468        if (len && str[len-1] == '}') {
 469                for (at = len-4; at >= 0; at--) {
 470                        if (str[at] == '@' && str[at+1] == '{') {
 471                                if (str[at+2] == '-') {
 472                                        if (at != 0)
 473                                                /* @{-N} not at start */
 474                                                return -1;
 475                                        nth_prior = 1;
 476                                        continue;
 477                                }
 478                                if (!upstream_mark(str + at, len - at)) {
 479                                        reflog_len = (len-1) - (at+2);
 480                                        len = at;
 481                                }
 482                                break;
 483                        }
 484                }
 485        }
 486
 487        /* Accept only unambiguous ref paths. */
 488        if (len && ambiguous_path(str, len))
 489                return -1;
 490
 491        if (nth_prior) {
 492                struct strbuf buf = STRBUF_INIT;
 493                int detached;
 494
 495                if (interpret_nth_prior_checkout(str, len, &buf) > 0) {
 496                        detached = (buf.len == 40 && !get_sha1_hex(buf.buf, sha1));
 497                        strbuf_release(&buf);
 498                        if (detached)
 499                                return 0;
 500                }
 501        }
 502
 503        if (!len && reflog_len)
 504                /* allow "@{...}" to mean the current branch reflog */
 505                refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
 506        else if (reflog_len)
 507                refs_found = dwim_log(str, len, sha1, &real_ref);
 508        else
 509                refs_found = dwim_ref(str, len, sha1, &real_ref);
 510
 511        if (!refs_found)
 512                return -1;
 513
 514        if (warn_ambiguous_refs &&
 515            (refs_found > 1 ||
 516             !get_short_sha1(str, len, tmp_sha1, GET_SHA1_QUIETLY)))
 517                warning(warn_msg, len, str);
 518
 519        if (reflog_len) {
 520                int nth, i;
 521                unsigned long at_time;
 522                unsigned long co_time;
 523                int co_tz, co_cnt;
 524
 525                /* Is it asking for N-th entry, or approxidate? */
 526                for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
 527                        char ch = str[at+2+i];
 528                        if ('0' <= ch && ch <= '9')
 529                                nth = nth * 10 + ch - '0';
 530                        else
 531                                nth = -1;
 532                }
 533                if (100000000 <= nth) {
 534                        at_time = nth;
 535                        nth = -1;
 536                } else if (0 <= nth)
 537                        at_time = 0;
 538                else {
 539                        int errors = 0;
 540                        char *tmp = xstrndup(str + at + 2, reflog_len);
 541                        at_time = approxidate_careful(tmp, &errors);
 542                        free(tmp);
 543                        if (errors) {
 544                                free(real_ref);
 545                                return -1;
 546                        }
 547                }
 548                if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
 549                                &co_time, &co_tz, &co_cnt)) {
 550                        if (!len) {
 551                                if (starts_with(real_ref, "refs/heads/")) {
 552                                        str = real_ref + 11;
 553                                        len = strlen(real_ref + 11);
 554                                } else {
 555                                        /* detached HEAD */
 556                                        str = "HEAD";
 557                                        len = 4;
 558                                }
 559                        }
 560                        if (at_time)
 561                                warning("Log for '%.*s' only goes "
 562                                        "back to %s.", len, str,
 563                                        show_date(co_time, co_tz, DATE_RFC2822));
 564                        else {
 565                                die("Log for '%.*s' only has %d entries.",
 566                                    len, str, co_cnt);
 567                        }
 568                }
 569        }
 570
 571        free(real_ref);
 572        return 0;
 573}
 574
 575static int get_parent(const char *name, int len,
 576                      unsigned char *result, int idx)
 577{
 578        unsigned char sha1[20];
 579        int ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
 580        struct commit *commit;
 581        struct commit_list *p;
 582
 583        if (ret)
 584                return ret;
 585        commit = lookup_commit_reference(sha1);
 586        if (parse_commit(commit))
 587                return -1;
 588        if (!idx) {
 589                hashcpy(result, commit->object.sha1);
 590                return 0;
 591        }
 592        p = commit->parents;
 593        while (p) {
 594                if (!--idx) {
 595                        hashcpy(result, p->item->object.sha1);
 596                        return 0;
 597                }
 598                p = p->next;
 599        }
 600        return -1;
 601}
 602
 603static int get_nth_ancestor(const char *name, int len,
 604                            unsigned char *result, int generation)
 605{
 606        unsigned char sha1[20];
 607        struct commit *commit;
 608        int ret;
 609
 610        ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
 611        if (ret)
 612                return ret;
 613        commit = lookup_commit_reference(sha1);
 614        if (!commit)
 615                return -1;
 616
 617        while (generation--) {
 618                if (parse_commit(commit) || !commit->parents)
 619                        return -1;
 620                commit = commit->parents->item;
 621        }
 622        hashcpy(result, commit->object.sha1);
 623        return 0;
 624}
 625
 626struct object *peel_to_type(const char *name, int namelen,
 627                            struct object *o, enum object_type expected_type)
 628{
 629        if (name && !namelen)
 630                namelen = strlen(name);
 631        while (1) {
 632                if (!o || (!o->parsed && !parse_object(o->sha1)))
 633                        return NULL;
 634                if (expected_type == OBJ_ANY || o->type == expected_type)
 635                        return o;
 636                if (o->type == OBJ_TAG)
 637                        o = ((struct tag*) o)->tagged;
 638                else if (o->type == OBJ_COMMIT)
 639                        o = &(((struct commit *) o)->tree->object);
 640                else {
 641                        if (name)
 642                                error("%.*s: expected %s type, but the object "
 643                                      "dereferences to %s type",
 644                                      namelen, name, typename(expected_type),
 645                                      typename(o->type));
 646                        return NULL;
 647                }
 648        }
 649}
 650
 651static int peel_onion(const char *name, int len, unsigned char *sha1)
 652{
 653        unsigned char outer[20];
 654        const char *sp;
 655        unsigned int expected_type = 0;
 656        unsigned lookup_flags = 0;
 657        struct object *o;
 658
 659        /*
 660         * "ref^{type}" dereferences ref repeatedly until you cannot
 661         * dereference anymore, or you get an object of given type,
 662         * whichever comes first.  "ref^{}" means just dereference
 663         * tags until you get a non-tag.  "ref^0" is a shorthand for
 664         * "ref^{commit}".  "commit^{tree}" could be used to find the
 665         * top-level tree of the given commit.
 666         */
 667        if (len < 4 || name[len-1] != '}')
 668                return -1;
 669
 670        for (sp = name + len - 1; name <= sp; sp--) {
 671                int ch = *sp;
 672                if (ch == '{' && name < sp && sp[-1] == '^')
 673                        break;
 674        }
 675        if (sp <= name)
 676                return -1;
 677
 678        sp++; /* beginning of type name, or closing brace for empty */
 679        if (starts_with(sp, "commit}"))
 680                expected_type = OBJ_COMMIT;
 681        else if (starts_with(sp, "tag}"))
 682                expected_type = OBJ_TAG;
 683        else if (starts_with(sp, "tree}"))
 684                expected_type = OBJ_TREE;
 685        else if (starts_with(sp, "blob}"))
 686                expected_type = OBJ_BLOB;
 687        else if (starts_with(sp, "object}"))
 688                expected_type = OBJ_ANY;
 689        else if (sp[0] == '}')
 690                expected_type = OBJ_NONE;
 691        else if (sp[0] == '/')
 692                expected_type = OBJ_COMMIT;
 693        else
 694                return -1;
 695
 696        if (expected_type == OBJ_COMMIT)
 697                lookup_flags = GET_SHA1_COMMITTISH;
 698        else if (expected_type == OBJ_TREE)
 699                lookup_flags = GET_SHA1_TREEISH;
 700
 701        if (get_sha1_1(name, sp - name - 2, outer, lookup_flags))
 702                return -1;
 703
 704        o = parse_object(outer);
 705        if (!o)
 706                return -1;
 707        if (!expected_type) {
 708                o = deref_tag(o, name, sp - name - 2);
 709                if (!o || (!o->parsed && !parse_object(o->sha1)))
 710                        return -1;
 711                hashcpy(sha1, o->sha1);
 712                return 0;
 713        }
 714
 715        /*
 716         * At this point, the syntax look correct, so
 717         * if we do not get the needed object, we should
 718         * barf.
 719         */
 720        o = peel_to_type(name, len, o, expected_type);
 721        if (!o)
 722                return -1;
 723
 724        hashcpy(sha1, o->sha1);
 725        if (sp[0] == '/') {
 726                /* "$commit^{/foo}" */
 727                char *prefix;
 728                int ret;
 729                struct commit_list *list = NULL;
 730
 731                /*
 732                 * $commit^{/}. Some regex implementation may reject.
 733                 * We don't need regex anyway. '' pattern always matches.
 734                 */
 735                if (sp[1] == '}')
 736                        return 0;
 737
 738                prefix = xstrndup(sp + 1, name + len - 1 - (sp + 1));
 739                commit_list_insert((struct commit *)o, &list);
 740                ret = get_sha1_oneline(prefix, sha1, list);
 741                free(prefix);
 742                return ret;
 743        }
 744        return 0;
 745}
 746
 747static int get_describe_name(const char *name, int len, unsigned char *sha1)
 748{
 749        const char *cp;
 750        unsigned flags = GET_SHA1_QUIETLY | GET_SHA1_COMMIT;
 751
 752        for (cp = name + len - 1; name + 2 <= cp; cp--) {
 753                char ch = *cp;
 754                if (hexval(ch) & ~0377) {
 755                        /* We must be looking at g in "SOMETHING-g"
 756                         * for it to be describe output.
 757                         */
 758                        if (ch == 'g' && cp[-1] == '-') {
 759                                cp++;
 760                                len -= cp - name;
 761                                return get_short_sha1(cp, len, sha1, flags);
 762                        }
 763                }
 764        }
 765        return -1;
 766}
 767
 768static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags)
 769{
 770        int ret, has_suffix;
 771        const char *cp;
 772
 773        /*
 774         * "name~3" is "name^^^", "name~" is "name~1", and "name^" is "name^1".
 775         */
 776        has_suffix = 0;
 777        for (cp = name + len - 1; name <= cp; cp--) {
 778                int ch = *cp;
 779                if ('0' <= ch && ch <= '9')
 780                        continue;
 781                if (ch == '~' || ch == '^')
 782                        has_suffix = ch;
 783                break;
 784        }
 785
 786        if (has_suffix) {
 787                int num = 0;
 788                int len1 = cp - name;
 789                cp++;
 790                while (cp < name + len)
 791                        num = num * 10 + *cp++ - '0';
 792                if (!num && len1 == len - 1)
 793                        num = 1;
 794                if (has_suffix == '^')
 795                        return get_parent(name, len1, sha1, num);
 796                /* else if (has_suffix == '~') -- goes without saying */
 797                return get_nth_ancestor(name, len1, sha1, num);
 798        }
 799
 800        ret = peel_onion(name, len, sha1);
 801        if (!ret)
 802                return 0;
 803
 804        ret = get_sha1_basic(name, len, sha1);
 805        if (!ret)
 806                return 0;
 807
 808        /* It could be describe output that is "SOMETHING-gXXXX" */
 809        ret = get_describe_name(name, len, sha1);
 810        if (!ret)
 811                return 0;
 812
 813        return get_short_sha1(name, len, sha1, lookup_flags);
 814}
 815
 816/*
 817 * This interprets names like ':/Initial revision of "git"' by searching
 818 * through history and returning the first commit whose message starts
 819 * the given regular expression.
 820 *
 821 * For future extension, ':/!' is reserved. If you want to match a message
 822 * beginning with a '!', you have to repeat the exclamation mark.
 823 */
 824
 825/* Remember to update object flag allocation in object.h */
 826#define ONELINE_SEEN (1u<<20)
 827
 828static int handle_one_ref(const char *path,
 829                const unsigned char *sha1, int flag, void *cb_data)
 830{
 831        struct commit_list **list = cb_data;
 832        struct object *object = parse_object(sha1);
 833        if (!object)
 834                return 0;
 835        if (object->type == OBJ_TAG) {
 836                object = deref_tag(object, path, strlen(path));
 837                if (!object)
 838                        return 0;
 839        }
 840        if (object->type != OBJ_COMMIT)
 841                return 0;
 842        commit_list_insert_by_date((struct commit *)object, list);
 843        return 0;
 844}
 845
 846static int get_sha1_oneline(const char *prefix, unsigned char *sha1,
 847                            struct commit_list *list)
 848{
 849        struct commit_list *backup = NULL, *l;
 850        int found = 0;
 851        regex_t regex;
 852
 853        if (prefix[0] == '!') {
 854                if (prefix[1] != '!')
 855                        die ("Invalid search pattern: %s", prefix);
 856                prefix++;
 857        }
 858
 859        if (regcomp(&regex, prefix, REG_EXTENDED))
 860                die("Invalid search pattern: %s", prefix);
 861
 862        for (l = list; l; l = l->next) {
 863                l->item->object.flags |= ONELINE_SEEN;
 864                commit_list_insert(l->item, &backup);
 865        }
 866        while (list) {
 867                const char *p, *buf;
 868                struct commit *commit;
 869                int matches;
 870
 871                commit = pop_most_recent_commit(&list, ONELINE_SEEN);
 872                if (!parse_object(commit->object.sha1))
 873                        continue;
 874                buf = get_commit_buffer(commit, NULL);
 875                p = strstr(buf, "\n\n");
 876                matches = p && !regexec(&regex, p + 2, 0, NULL, 0);
 877                unuse_commit_buffer(commit, buf);
 878
 879                if (matches) {
 880                        hashcpy(sha1, commit->object.sha1);
 881                        found = 1;
 882                        break;
 883                }
 884        }
 885        regfree(&regex);
 886        free_commit_list(list);
 887        for (l = backup; l; l = l->next)
 888                clear_commit_marks(l->item, ONELINE_SEEN);
 889        free_commit_list(backup);
 890        return found ? 0 : -1;
 891}
 892
 893struct grab_nth_branch_switch_cbdata {
 894        int remaining;
 895        struct strbuf buf;
 896};
 897
 898static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
 899                                  const char *email, unsigned long timestamp, int tz,
 900                                  const char *message, void *cb_data)
 901{
 902        struct grab_nth_branch_switch_cbdata *cb = cb_data;
 903        const char *match = NULL, *target = NULL;
 904        size_t len;
 905
 906        if (skip_prefix(message, "checkout: moving from ", &match))
 907                target = strstr(match, " to ");
 908
 909        if (!match || !target)
 910                return 0;
 911        if (--(cb->remaining) == 0) {
 912                len = target - match;
 913                strbuf_reset(&cb->buf);
 914                strbuf_add(&cb->buf, match, len);
 915                return 1; /* we are done */
 916        }
 917        return 0;
 918}
 919
 920/*
 921 * Parse @{-N} syntax, return the number of characters parsed
 922 * if successful; otherwise signal an error with negative value.
 923 */
 924static int interpret_nth_prior_checkout(const char *name, int namelen,
 925                                        struct strbuf *buf)
 926{
 927        long nth;
 928        int retval;
 929        struct grab_nth_branch_switch_cbdata cb;
 930        const char *brace;
 931        char *num_end;
 932
 933        if (namelen < 4)
 934                return -1;
 935        if (name[0] != '@' || name[1] != '{' || name[2] != '-')
 936                return -1;
 937        brace = memchr(name, '}', namelen);
 938        if (!brace)
 939                return -1;
 940        nth = strtol(name + 3, &num_end, 10);
 941        if (num_end != brace)
 942                return -1;
 943        if (nth <= 0)
 944                return -1;
 945        cb.remaining = nth;
 946        strbuf_init(&cb.buf, 20);
 947
 948        retval = 0;
 949        if (0 < for_each_reflog_ent_reverse("HEAD", grab_nth_branch_switch, &cb)) {
 950                strbuf_reset(buf);
 951                strbuf_addbuf(buf, &cb.buf);
 952                retval = brace - name + 1;
 953        }
 954
 955        strbuf_release(&cb.buf);
 956        return retval;
 957}
 958
 959int get_sha1_mb(const char *name, unsigned char *sha1)
 960{
 961        struct commit *one, *two;
 962        struct commit_list *mbs;
 963        unsigned char sha1_tmp[20];
 964        const char *dots;
 965        int st;
 966
 967        dots = strstr(name, "...");
 968        if (!dots)
 969                return get_sha1(name, sha1);
 970        if (dots == name)
 971                st = get_sha1("HEAD", sha1_tmp);
 972        else {
 973                struct strbuf sb;
 974                strbuf_init(&sb, dots - name);
 975                strbuf_add(&sb, name, dots - name);
 976                st = get_sha1_committish(sb.buf, sha1_tmp);
 977                strbuf_release(&sb);
 978        }
 979        if (st)
 980                return st;
 981        one = lookup_commit_reference_gently(sha1_tmp, 0);
 982        if (!one)
 983                return -1;
 984
 985        if (get_sha1_committish(dots[3] ? (dots + 3) : "HEAD", sha1_tmp))
 986                return -1;
 987        two = lookup_commit_reference_gently(sha1_tmp, 0);
 988        if (!two)
 989                return -1;
 990        mbs = get_merge_bases(one, two, 1);
 991        if (!mbs || mbs->next)
 992                st = -1;
 993        else {
 994                st = 0;
 995                hashcpy(sha1, mbs->item->object.sha1);
 996        }
 997        free_commit_list(mbs);
 998        return st;
 999}
1000
1001/* parse @something syntax, when 'something' is not {.*} */
1002static int interpret_empty_at(const char *name, int namelen, int len, struct strbuf *buf)
1003{
1004        const char *next;
1005
1006        if (len || name[1] == '{')
1007                return -1;
1008
1009        /* make sure it's a single @, or @@{.*}, not @foo */
1010        next = memchr(name + len + 1, '@', namelen - len - 1);
1011        if (next && next[1] != '{')
1012                return -1;
1013        if (!next)
1014                next = name + namelen;
1015        if (next != name + 1)
1016                return -1;
1017
1018        strbuf_reset(buf);
1019        strbuf_add(buf, "HEAD", 4);
1020        return 1;
1021}
1022
1023static int reinterpret(const char *name, int namelen, int len, struct strbuf *buf)
1024{
1025        /* we have extra data, which might need further processing */
1026        struct strbuf tmp = STRBUF_INIT;
1027        int used = buf->len;
1028        int ret;
1029
1030        strbuf_add(buf, name + len, namelen - len);
1031        ret = interpret_branch_name(buf->buf, buf->len, &tmp);
1032        /* that data was not interpreted, remove our cruft */
1033        if (ret < 0) {
1034                strbuf_setlen(buf, used);
1035                return len;
1036        }
1037        strbuf_reset(buf);
1038        strbuf_addbuf(buf, &tmp);
1039        strbuf_release(&tmp);
1040        /* tweak for size of {-N} versus expanded ref name */
1041        return ret - used + len;
1042}
1043
1044static void set_shortened_ref(struct strbuf *buf, const char *ref)
1045{
1046        char *s = shorten_unambiguous_ref(ref, 0);
1047        strbuf_reset(buf);
1048        strbuf_addstr(buf, s);
1049        free(s);
1050}
1051
1052static const char *get_upstream_branch(const char *branch_buf, int len)
1053{
1054        char *branch = xstrndup(branch_buf, len);
1055        struct branch *upstream = branch_get(*branch ? branch : NULL);
1056
1057        /*
1058         * Upstream can be NULL only if branch refers to HEAD and HEAD
1059         * points to something different than a branch.
1060         */
1061        if (!upstream)
1062                die(_("HEAD does not point to a branch"));
1063        if (!upstream->merge || !upstream->merge[0]->dst) {
1064                if (!ref_exists(upstream->refname))
1065                        die(_("No such branch: '%s'"), branch);
1066                if (!upstream->merge) {
1067                        die(_("No upstream configured for branch '%s'"),
1068                                upstream->name);
1069                }
1070                die(
1071                        _("Upstream branch '%s' not stored as a remote-tracking branch"),
1072                        upstream->merge[0]->src);
1073        }
1074        free(branch);
1075
1076        return upstream->merge[0]->dst;
1077}
1078
1079static int interpret_upstream_mark(const char *name, int namelen,
1080                                   int at, struct strbuf *buf)
1081{
1082        int len;
1083
1084        len = upstream_mark(name + at, namelen - at);
1085        if (!len)
1086                return -1;
1087
1088        if (memchr(name, ':', at))
1089                return -1;
1090
1091        set_shortened_ref(buf, get_upstream_branch(name, at));
1092        return len + at;
1093}
1094
1095/*
1096 * This reads short-hand syntax that not only evaluates to a commit
1097 * object name, but also can act as if the end user spelled the name
1098 * of the branch from the command line.
1099 *
1100 * - "@{-N}" finds the name of the Nth previous branch we were on, and
1101 *   places the name of the branch in the given buf and returns the
1102 *   number of characters parsed if successful.
1103 *
1104 * - "<branch>@{upstream}" finds the name of the other ref that
1105 *   <branch> is configured to merge with (missing <branch> defaults
1106 *   to the current branch), and places the name of the branch in the
1107 *   given buf and returns the number of characters parsed if
1108 *   successful.
1109 *
1110 * If the input is not of the accepted format, it returns a negative
1111 * number to signal an error.
1112 *
1113 * If the input was ok but there are not N branch switches in the
1114 * reflog, it returns 0.
1115 */
1116int interpret_branch_name(const char *name, int namelen, struct strbuf *buf)
1117{
1118        char *at;
1119        const char *start;
1120        int len = interpret_nth_prior_checkout(name, namelen, buf);
1121
1122        if (!namelen)
1123                namelen = strlen(name);
1124
1125        if (!len) {
1126                return len; /* syntax Ok, not enough switches */
1127        } else if (len > 0) {
1128                if (len == namelen)
1129                        return len; /* consumed all */
1130                else
1131                        return reinterpret(name, namelen, len, buf);
1132        }
1133
1134        for (start = name;
1135             (at = memchr(start, '@', namelen - (start - name)));
1136             start = at + 1) {
1137
1138                len = interpret_empty_at(name, namelen, at - name, buf);
1139                if (len > 0)
1140                        return reinterpret(name, namelen, len, buf);
1141
1142                len = interpret_upstream_mark(name, namelen, at - name, buf);
1143                if (len > 0)
1144                        return len;
1145        }
1146
1147        return -1;
1148}
1149
1150int strbuf_branchname(struct strbuf *sb, const char *name)
1151{
1152        int len = strlen(name);
1153        int used = interpret_branch_name(name, len, sb);
1154
1155        if (used == len)
1156                return 0;
1157        if (used < 0)
1158                used = 0;
1159        strbuf_add(sb, name + used, len - used);
1160        return len;
1161}
1162
1163int strbuf_check_branch_ref(struct strbuf *sb, const char *name)
1164{
1165        strbuf_branchname(sb, name);
1166        if (name[0] == '-')
1167                return -1;
1168        strbuf_splice(sb, 0, 0, "refs/heads/", 11);
1169        return check_refname_format(sb->buf, 0);
1170}
1171
1172/*
1173 * This is like "get_sha1_basic()", except it allows "sha1 expressions",
1174 * notably "xyz^" for "parent of xyz"
1175 */
1176int get_sha1(const char *name, unsigned char *sha1)
1177{
1178        struct object_context unused;
1179        return get_sha1_with_context(name, 0, sha1, &unused);
1180}
1181
1182/*
1183 * Many callers know that the user meant to name a commit-ish by
1184 * syntactical positions where the object name appears.  Calling this
1185 * function allows the machinery to disambiguate shorter-than-unique
1186 * abbreviated object names between commit-ish and others.
1187 *
1188 * Note that this does NOT error out when the named object is not a
1189 * commit-ish. It is merely to give a hint to the disambiguation
1190 * machinery.
1191 */
1192int get_sha1_committish(const char *name, unsigned char *sha1)
1193{
1194        struct object_context unused;
1195        return get_sha1_with_context(name, GET_SHA1_COMMITTISH,
1196                                     sha1, &unused);
1197}
1198
1199int get_sha1_treeish(const char *name, unsigned char *sha1)
1200{
1201        struct object_context unused;
1202        return get_sha1_with_context(name, GET_SHA1_TREEISH,
1203                                     sha1, &unused);
1204}
1205
1206int get_sha1_commit(const char *name, unsigned char *sha1)
1207{
1208        struct object_context unused;
1209        return get_sha1_with_context(name, GET_SHA1_COMMIT,
1210                                     sha1, &unused);
1211}
1212
1213int get_sha1_tree(const char *name, unsigned char *sha1)
1214{
1215        struct object_context unused;
1216        return get_sha1_with_context(name, GET_SHA1_TREE,
1217                                     sha1, &unused);
1218}
1219
1220int get_sha1_blob(const char *name, unsigned char *sha1)
1221{
1222        struct object_context unused;
1223        return get_sha1_with_context(name, GET_SHA1_BLOB,
1224                                     sha1, &unused);
1225}
1226
1227/* Must be called only when object_name:filename doesn't exist. */
1228static void diagnose_invalid_sha1_path(const char *prefix,
1229                                       const char *filename,
1230                                       const unsigned char *tree_sha1,
1231                                       const char *object_name,
1232                                       int object_name_len)
1233{
1234        struct stat st;
1235        unsigned char sha1[20];
1236        unsigned mode;
1237
1238        if (!prefix)
1239                prefix = "";
1240
1241        if (!lstat(filename, &st))
1242                die("Path '%s' exists on disk, but not in '%.*s'.",
1243                    filename, object_name_len, object_name);
1244        if (errno == ENOENT || errno == ENOTDIR) {
1245                char *fullname = xstrfmt("%s%s", prefix, filename);
1246
1247                if (!get_tree_entry(tree_sha1, fullname,
1248                                    sha1, &mode)) {
1249                        die("Path '%s' exists, but not '%s'.\n"
1250                            "Did you mean '%.*s:%s' aka '%.*s:./%s'?",
1251                            fullname,
1252                            filename,
1253                            object_name_len, object_name,
1254                            fullname,
1255                            object_name_len, object_name,
1256                            filename);
1257                }
1258                die("Path '%s' does not exist in '%.*s'",
1259                    filename, object_name_len, object_name);
1260        }
1261}
1262
1263/* Must be called only when :stage:filename doesn't exist. */
1264static void diagnose_invalid_index_path(int stage,
1265                                        const char *prefix,
1266                                        const char *filename)
1267{
1268        struct stat st;
1269        const struct cache_entry *ce;
1270        int pos;
1271        unsigned namelen = strlen(filename);
1272        unsigned fullnamelen;
1273        char *fullname;
1274
1275        if (!prefix)
1276                prefix = "";
1277
1278        /* Wrong stage number? */
1279        pos = cache_name_pos(filename, namelen);
1280        if (pos < 0)
1281                pos = -pos - 1;
1282        if (pos < active_nr) {
1283                ce = active_cache[pos];
1284                if (ce_namelen(ce) == namelen &&
1285                    !memcmp(ce->name, filename, namelen))
1286                        die("Path '%s' is in the index, but not at stage %d.\n"
1287                            "Did you mean ':%d:%s'?",
1288                            filename, stage,
1289                            ce_stage(ce), filename);
1290        }
1291
1292        /* Confusion between relative and absolute filenames? */
1293        fullnamelen = namelen + strlen(prefix);
1294        fullname = xmalloc(fullnamelen + 1);
1295        strcpy(fullname, prefix);
1296        strcat(fullname, filename);
1297        pos = cache_name_pos(fullname, fullnamelen);
1298        if (pos < 0)
1299                pos = -pos - 1;
1300        if (pos < active_nr) {
1301                ce = active_cache[pos];
1302                if (ce_namelen(ce) == fullnamelen &&
1303                    !memcmp(ce->name, fullname, fullnamelen))
1304                        die("Path '%s' is in the index, but not '%s'.\n"
1305                            "Did you mean ':%d:%s' aka ':%d:./%s'?",
1306                            fullname, filename,
1307                            ce_stage(ce), fullname,
1308                            ce_stage(ce), filename);
1309        }
1310
1311        if (!lstat(filename, &st))
1312                die("Path '%s' exists on disk, but not in the index.", filename);
1313        if (errno == ENOENT || errno == ENOTDIR)
1314                die("Path '%s' does not exist (neither on disk nor in the index).",
1315                    filename);
1316
1317        free(fullname);
1318}
1319
1320
1321static char *resolve_relative_path(const char *rel)
1322{
1323        if (!starts_with(rel, "./") && !starts_with(rel, "../"))
1324                return NULL;
1325
1326        if (!startup_info)
1327                die("BUG: startup_info struct is not initialized.");
1328
1329        if (!is_inside_work_tree())
1330                die("relative path syntax can't be used outside working tree.");
1331
1332        /* die() inside prefix_path() if resolved path is outside worktree */
1333        return prefix_path(startup_info->prefix,
1334                           startup_info->prefix ? strlen(startup_info->prefix) : 0,
1335                           rel);
1336}
1337
1338static int get_sha1_with_context_1(const char *name,
1339                                   unsigned flags,
1340                                   const char *prefix,
1341                                   unsigned char *sha1,
1342                                   struct object_context *oc)
1343{
1344        int ret, bracket_depth;
1345        int namelen = strlen(name);
1346        const char *cp;
1347        int only_to_die = flags & GET_SHA1_ONLY_TO_DIE;
1348
1349        memset(oc, 0, sizeof(*oc));
1350        oc->mode = S_IFINVALID;
1351        ret = get_sha1_1(name, namelen, sha1, flags);
1352        if (!ret)
1353                return ret;
1354        /*
1355         * sha1:path --> object name of path in ent sha1
1356         * :path -> object name of absolute path in index
1357         * :./path -> object name of path relative to cwd in index
1358         * :[0-3]:path -> object name of path in index at stage
1359         * :/foo -> recent commit matching foo
1360         */
1361        if (name[0] == ':') {
1362                int stage = 0;
1363                const struct cache_entry *ce;
1364                char *new_path = NULL;
1365                int pos;
1366                if (!only_to_die && namelen > 2 && name[1] == '/') {
1367                        struct commit_list *list = NULL;
1368                        for_each_ref(handle_one_ref, &list);
1369                        return get_sha1_oneline(name + 2, sha1, list);
1370                }
1371                if (namelen < 3 ||
1372                    name[2] != ':' ||
1373                    name[1] < '0' || '3' < name[1])
1374                        cp = name + 1;
1375                else {
1376                        stage = name[1] - '0';
1377                        cp = name + 3;
1378                }
1379                new_path = resolve_relative_path(cp);
1380                if (!new_path) {
1381                        namelen = namelen - (cp - name);
1382                } else {
1383                        cp = new_path;
1384                        namelen = strlen(cp);
1385                }
1386
1387                strncpy(oc->path, cp,
1388                        sizeof(oc->path));
1389                oc->path[sizeof(oc->path)-1] = '\0';
1390
1391                if (!active_cache)
1392                        read_cache();
1393                pos = cache_name_pos(cp, namelen);
1394                if (pos < 0)
1395                        pos = -pos - 1;
1396                while (pos < active_nr) {
1397                        ce = active_cache[pos];
1398                        if (ce_namelen(ce) != namelen ||
1399                            memcmp(ce->name, cp, namelen))
1400                                break;
1401                        if (ce_stage(ce) == stage) {
1402                                hashcpy(sha1, ce->sha1);
1403                                oc->mode = ce->ce_mode;
1404                                free(new_path);
1405                                return 0;
1406                        }
1407                        pos++;
1408                }
1409                if (only_to_die && name[1] && name[1] != '/')
1410                        diagnose_invalid_index_path(stage, prefix, cp);
1411                free(new_path);
1412                return -1;
1413        }
1414        for (cp = name, bracket_depth = 0; *cp; cp++) {
1415                if (*cp == '{')
1416                        bracket_depth++;
1417                else if (bracket_depth && *cp == '}')
1418                        bracket_depth--;
1419                else if (!bracket_depth && *cp == ':')
1420                        break;
1421        }
1422        if (*cp == ':') {
1423                unsigned char tree_sha1[20];
1424                int len = cp - name;
1425                if (!get_sha1_1(name, len, tree_sha1, GET_SHA1_TREEISH)) {
1426                        const char *filename = cp+1;
1427                        char *new_filename = NULL;
1428
1429                        new_filename = resolve_relative_path(filename);
1430                        if (new_filename)
1431                                filename = new_filename;
1432                        ret = get_tree_entry(tree_sha1, filename, sha1, &oc->mode);
1433                        if (ret && only_to_die) {
1434                                diagnose_invalid_sha1_path(prefix, filename,
1435                                                           tree_sha1,
1436                                                           name, len);
1437                        }
1438                        hashcpy(oc->tree, tree_sha1);
1439                        strncpy(oc->path, filename,
1440                                sizeof(oc->path));
1441                        oc->path[sizeof(oc->path)-1] = '\0';
1442
1443                        free(new_filename);
1444                        return ret;
1445                } else {
1446                        if (only_to_die)
1447                                die("Invalid object name '%.*s'.", len, name);
1448                }
1449        }
1450        return ret;
1451}
1452
1453/*
1454 * Call this function when you know "name" given by the end user must
1455 * name an object but it doesn't; the function _may_ die with a better
1456 * diagnostic message than "no such object 'name'", e.g. "Path 'doc' does not
1457 * exist in 'HEAD'" when given "HEAD:doc", or it may return in which case
1458 * you have a chance to diagnose the error further.
1459 */
1460void maybe_die_on_misspelt_object_name(const char *name, const char *prefix)
1461{
1462        struct object_context oc;
1463        unsigned char sha1[20];
1464        get_sha1_with_context_1(name, GET_SHA1_ONLY_TO_DIE, prefix, sha1, &oc);
1465}
1466
1467int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc)
1468{
1469        return get_sha1_with_context_1(str, flags, NULL, sha1, orc);
1470}