sha1_name.c

   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
  10 static int get_sha1_oneline(const char *, unsigned char *, struct commit_list *);
  11
  12 typedef int (*disambiguate_hint_fn)(const unsigned char *, void *);
  13
  14 struct 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
  26 static 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 satisify 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
  74 static 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
 122 static 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
 137 static 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
 179 static 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
 192 static 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
 226 static 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
 232 static 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(lookup_object(sha1), NULL, 0);
 245         if (obj && obj->type == OBJ_COMMIT)
 246                 return 1;
 247         return 0;
 248 }
 249
 250 static 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
 256 static 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
 274 static 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
 280 static 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
 309 static 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
 346
 347 int for_each_abbrev(const char *prefix, each_abbrev_fn fn, void *cb_data)
 348 {
 349         char hex_pfx[40];
 350         unsigned char bin_pfx[20];
 351         struct disambiguate_state ds;
 352         int len = strlen(prefix);
 353
 354         if (len < MINIMUM_ABBREV || len > 40)
 355                 return -1;
 356         if (prepare_prefixes(prefix, len, bin_pfx, hex_pfx) < 0)
 357                 return -1;
 358
 359         prepare_alt_odb();
 360
 361         memset(&ds, 0, sizeof(ds));
 362         ds.always_call_fn = 1;
 363         ds.cb_data = cb_data;
 364         ds.fn = fn;
 365
 366         find_short_object_filename(len, hex_pfx, &ds);
 367         find_short_packed_object(len, bin_pfx, &ds);
 368         return ds.ambiguous;
 369 }
 370
 371 const char *find_unique_abbrev(const unsigned char *sha1, int len)
 372 {
 373         int status, exists;
 374         static char hex[41];
 375
 376         exists = has_sha1_file(sha1);
 377         memcpy(hex, sha1_to_hex(sha1), 40);
 378         if (len == 40 || !len)
 379                 return hex;
 380         while (len < 40) {
 381                 unsigned char sha1_ret[20];
 382                 status = get_short_sha1(hex, len, sha1_ret, GET_SHA1_QUIETLY);
 383                 if (exists
 384                     ? !status
 385                     : status == SHORT_NAME_NOT_FOUND) {
 386                         hex[len] = 0;
 387                         return hex;
 388                 }
 389                 len++;
 390         }
 391         return hex;
 392 }
 393
 394 static int ambiguous_path(const char *path, int len)
 395 {
 396         int slash = 1;
 397         int cnt;
 398
 399         for (cnt = 0; cnt < len; cnt++) {
 400                 switch (*path++) {
 401                 case '\0':
 402                         break;
 403                 case '/':
 404                         if (slash)
 405                                 break;
 406                         slash = 1;
 407                         continue;
 408                 case '.':
 409                         continue;
 410                 default:
 411                         slash = 0;
 412                         continue;
 413                 }
 414                 break;
 415         }
 416         return slash;
 417 }
 418
 419 static inline int upstream_mark(const char *string, int len)
 420 {
 421         const char *suffix[] = { "@{upstream}", "@{u}" };
 422         int i;
 423
 424         for (i = 0; i < ARRAY_SIZE(suffix); i++) {
 425                 int suffix_len = strlen(suffix[i]);
 426                 if (suffix_len <= len
 427                     && !memcmp(string, suffix[i], suffix_len))
 428                         return suffix_len;
 429         }
 430         return 0;
 431 }
 432
 433 static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags);
 434
 435 static 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.object_name_warning false\"");
 448         unsigned char tmp_sha1[20];
 449         char *real_ref = NULL;
 450         int refs_found = 0;
 451         int at, reflog_len;
 452
 453         if (len == 40 && !get_sha1_hex(str, sha1)) {
 454                 if (warn_on_object_refname_ambiguity) {
 455                         refs_found = dwim_ref(str, len, tmp_sha1, &real_ref);
 456                         if (refs_found > 0 && warn_ambiguous_refs) {
 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-2; at >= 0; at--) {
 470                         if (str[at] == '@' && str[at+1] == '{') {
 471                                 if (!upstream_mark(str + at, len - at)) {
 472                                         reflog_len = (len-1) - (at+2);
 473                                         len = at;
 474                                 }
 475                                 break;
 476                         }
 477                 }
 478         }
 479
 480         /* Accept only unambiguous ref paths. */
 481         if (len && ambiguous_path(str, len))
 482                 return -1;
 483
 484         if (!len && reflog_len) {
 485                 struct strbuf buf = STRBUF_INIT;
 486                 int ret;
 487                 /* try the @{-N} syntax for n-th checkout */
 488                 ret = interpret_branch_name(str+at, &buf);
 489                 if (ret > 0) {
 490                         /* substitute this branch name and restart */
 491                         return get_sha1_1(buf.buf, buf.len, sha1, 0);
 492                 } else if (ret == 0) {
 493                         return -1;
 494                 }
 495                 /* allow "@{...}" to mean the current branch reflog */
 496                 refs_found = dwim_ref("HEAD", 4, sha1, &real_ref);
 497         } else if (reflog_len)
 498                 refs_found = dwim_log(str, len, sha1, &real_ref);
 499         else
 500                 refs_found = dwim_ref(str, len, sha1, &real_ref);
 501
 502         if (!refs_found)
 503                 return -1;
 504
 505         if (warn_ambiguous_refs &&
 506             (refs_found > 1 ||
 507              !get_short_sha1(str, len, tmp_sha1, GET_SHA1_QUIETLY)))
 508                 warning(warn_msg, len, str);
 509
 510         if (reflog_len) {
 511                 int nth, i;
 512                 unsigned long at_time;
 513                 unsigned long co_time;
 514                 int co_tz, co_cnt;
 515
 516                 /* a @{-N} placed anywhere except the start is an error */
 517                 if (str[at+2] == '-')
 518                         return -1;
 519
 520                 /* Is it asking for N-th entry, or approxidate? */
 521                 for (i = nth = 0; 0 <= nth && i < reflog_len; i++) {
 522                         char ch = str[at+2+i];
 523                         if ('0' <= ch && ch <= '9')
 524                                 nth = nth * 10 + ch - '0';
 525                         else
 526                                 nth = -1;
 527                 }
 528                 if (100000000 <= nth) {
 529                         at_time = nth;
 530                         nth = -1;
 531                 } else if (0 <= nth)
 532                         at_time = 0;
 533                 else {
 534                         int errors = 0;
 535                         char *tmp = xstrndup(str + at + 2, reflog_len);
 536                         at_time = approxidate_careful(tmp, &errors);
 537                         free(tmp);
 538                         if (errors)
 539                                 return -1;
 540                 }
 541                 if (read_ref_at(real_ref, at_time, nth, sha1, NULL,
 542                                 &co_time, &co_tz, &co_cnt)) {
 543                         if (at_time)
 544                                 warning("Log for '%.*s' only goes "
 545                                         "back to %s.", len, str,
 546                                         show_date(co_time, co_tz, DATE_RFC2822));
 547                         else {
 548                                 free(real_ref);
 549                                 die("Log for '%.*s' only has %d entries.",
 550                                     len, str, co_cnt);
 551                         }
 552                 }
 553         }
 554
 555         free(real_ref);
 556         return 0;
 557 }
 558
 559 static int get_parent(const char *name, int len,
 560                       unsigned char *result, int idx)
 561 {
 562         unsigned char sha1[20];
 563         int ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
 564         struct commit *commit;
 565         struct commit_list *p;
 566
 567         if (ret)
 568                 return ret;
 569         commit = lookup_commit_reference(sha1);
 570         if (!commit)
 571                 return -1;
 572         if (parse_commit(commit))
 573                 return -1;
 574         if (!idx) {
 575                 hashcpy(result, commit->object.sha1);
 576                 return 0;
 577         }
 578         p = commit->parents;
 579         while (p) {
 580                 if (!--idx) {
 581                         hashcpy(result, p->item->object.sha1);
 582                         return 0;
 583                 }
 584                 p = p->next;
 585         }
 586         return -1;
 587 }
 588
 589 static int get_nth_ancestor(const char *name, int len,
 590                             unsigned char *result, int generation)
 591 {
 592         unsigned char sha1[20];
 593         struct commit *commit;
 594         int ret;
 595
 596         ret = get_sha1_1(name, len, sha1, GET_SHA1_COMMITTISH);
 597         if (ret)
 598                 return ret;
 599         commit = lookup_commit_reference(sha1);
 600         if (!commit)
 601                 return -1;
 602
 603         while (generation--) {
 604                 if (parse_commit(commit) || !commit->parents)
 605                         return -1;
 606                 commit = commit->parents->item;
 607         }
 608         hashcpy(result, commit->object.sha1);
 609         return 0;
 610 }
 611
 612 struct object *peel_to_type(const char *name, int namelen,
 613                             struct object *o, enum object_type expected_type)
 614 {
 615         if (name && !namelen)
 616                 namelen = strlen(name);
 617         while (1) {
 618                 if (!o || (!o->parsed && !parse_object(o->sha1)))
 619                         return NULL;
 620                 if (expected_type == OBJ_ANY || o->type == expected_type)
 621                         return o;
 622                 if (o->type == OBJ_TAG)
 623                         o = ((struct tag*) o)->tagged;
 624                 else if (o->type == OBJ_COMMIT)
 625                         o = &(((struct commit *) o)->tree->object);
 626                 else {
 627                         if (name)
 628                                 error("%.*s: expected %s type, but the object "
 629                                       "dereferences to %s type",
 630                                       namelen, name, typename(expected_type),
 631                                       typename(o->type));
 632                         return NULL;
 633                 }
 634         }
 635 }
 636
 637 static int peel_onion(const char *name, int len, unsigned char *sha1)
 638 {
 639         unsigned char outer[20];
 640         const char *sp;
 641         unsigned int expected_type = 0;
 642         unsigned lookup_flags = 0;
 643         struct object *o;
 644
 645         /*
 646          * "ref^{type}" dereferences ref repeatedly until you cannot
 647          * dereference anymore, or you get an object of given type,
 648          * whichever comes first.  "ref^{}" means just dereference
 649          * tags until you get a non-tag.  "ref^0" is a shorthand for
 650          * "ref^{commit}".  "commit^{tree}" could be used to find the
 651          * top-level tree of the given commit.
 652          */
 653         if (len < 4 || name[len-1] != '}')
 654                 return -1;
 655
 656         for (sp = name + len - 1; name <= sp; sp--) {
 657                 int ch = *sp;
 658                 if (ch == '{' && name < sp && sp[-1] == '^')
 659                         break;
 660         }
 661         if (sp <= name)
 662                 return -1;
 663
 664         sp++; /* beginning of type name, or closing brace for empty */
 665         if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
 666                 expected_type = OBJ_COMMIT;
 667         else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
 668                 expected_type = OBJ_TREE;
 669         else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
 670                 expected_type = OBJ_BLOB;
 671         else if (!prefixcmp(sp, "object}"))
 672                 expected_type = OBJ_ANY;
 673         else if (sp[0] == '}')
 674                 expected_type = OBJ_NONE;
 675         else if (sp[0] == '/')
 676                 expected_type = OBJ_COMMIT;
 677         else
 678                 return -1;
 679
 680         if (expected_type == OBJ_COMMIT)
 681                 lookup_flags = GET_SHA1_COMMITTISH;
 682         else if (expected_type == OBJ_TREE)
 683                 lookup_flags = GET_SHA1_TREEISH;
 684
 685         if (get_sha1_1(name, sp - name - 2, outer, lookup_flags))
 686                 return -1;
 687
 688         o = parse_object(outer);
 689         if (!o)
 690                 return -1;
 691         if (!expected_type) {
 692                 o = deref_tag(o, name, sp - name - 2);
 693                 if (!o || (!o->parsed && !parse_object(o->sha1)))
 694                         return -1;
 695                 hashcpy(sha1, o->sha1);
 696                 return 0;
 697         }
 698
 699         /*
 700          * At this point, the syntax look correct, so
 701          * if we do not get the needed object, we should
 702          * barf.
 703          */
 704         o = peel_to_type(name, len, o, expected_type);
 705         if (!o)
 706                 return -1;
 707
 708         hashcpy(sha1, o->sha1);
 709         if (sp[0] == '/') {
 710                 /* "$commit^{/foo}" */
 711                 char *prefix;
 712                 int ret;
 713                 struct commit_list *list = NULL;
 714
 715                 /*
 716                  * $commit^{/}. Some regex implementation may reject.
 717                  * We don't need regex anyway. '' pattern always matches.
 718                  */
 719                 if (sp[1] == '}')
 720                         return 0;
 721
 722                 prefix = xstrndup(sp + 1, name + len - 1 - (sp + 1));
 723                 commit_list_insert((struct commit *)o, &list);
 724                 ret = get_sha1_oneline(prefix, sha1, list);
 725                 free(prefix);
 726                 return ret;
 727         }
 728         return 0;
 729 }
 730
 731 static int get_describe_name(const char *name, int len, unsigned char *sha1)
 732 {
 733         const char *cp;
 734         unsigned flags = GET_SHA1_QUIETLY | GET_SHA1_COMMIT;
 735
 736         for (cp = name + len - 1; name + 2 <= cp; cp--) {
 737                 char ch = *cp;
 738                 if (hexval(ch) & ~0377) {
 739                         /* We must be looking at g in "SOMETHING-g"
 740                          * for it to be describe output.
 741                          */
 742                         if (ch == 'g' && cp[-1] == '-') {
 743                                 cp++;
 744                                 len -= cp - name;
 745                                 return get_short_sha1(cp, len, sha1, flags);
 746                         }
 747                 }
 748         }
 749         return -1;
 750 }
 751
 752 static int get_sha1_1(const char *name, int len, unsigned char *sha1, unsigned lookup_flags)
 753 {
 754         int ret, has_suffix;
 755         const char *cp;
 756
 757         /*
 758          * "name~3" is "name^^^", "name~" is "name~1", and "name^" is "name^1".
 759          */
 760         has_suffix = 0;
 761         for (cp = name + len - 1; name <= cp; cp--) {
 762                 int ch = *cp;
 763                 if ('0' <= ch && ch <= '9')
 764                         continue;
 765                 if (ch == '~' || ch == '^')
 766                         has_suffix = ch;
 767                 break;
 768         }
 769
 770         if (has_suffix) {
 771                 int num = 0;
 772                 int len1 = cp - name;
 773                 cp++;
 774                 while (cp < name + len)
 775                         num = num * 10 + *cp++ - '0';
 776                 if (!num && len1 == len - 1)
 777                         num = 1;
 778                 if (has_suffix == '^')
 779                         return get_parent(name, len1, sha1, num);
 780                 /* else if (has_suffix == '~') -- goes without saying */
 781                 return get_nth_ancestor(name, len1, sha1, num);
 782         }
 783
 784         ret = peel_onion(name, len, sha1);
 785         if (!ret)
 786                 return 0;
 787
 788         ret = get_sha1_basic(name, len, sha1);
 789         if (!ret)
 790                 return 0;
 791
 792         /* It could be describe output that is "SOMETHING-gXXXX" */
 793         ret = get_describe_name(name, len, sha1);
 794         if (!ret)
 795                 return 0;
 796
 797         return get_short_sha1(name, len, sha1, lookup_flags);
 798 }
 799
 800 /*
 801  * This interprets names like ':/Initial revision of "git"' by searching
 802  * through history and returning the first commit whose message starts
 803  * the given regular expression.
 804  *
 805  * For future extension, ':/!' is reserved. If you want to match a message
 806  * beginning with a '!', you have to repeat the exclamation mark.
 807  */
 808 #define ONELINE_SEEN (1u<<20)
 809
 810 static int handle_one_ref(const char *path,
 811                 const unsigned char *sha1, int flag, void *cb_data)
 812 {
 813         struct commit_list **list = cb_data;
 814         struct object *object = parse_object(sha1);
 815         if (!object)
 816                 return 0;
 817         if (object->type == OBJ_TAG) {
 818                 object = deref_tag(object, path, strlen(path));
 819                 if (!object)
 820                         return 0;
 821         }
 822         if (object->type != OBJ_COMMIT)
 823                 return 0;
 824         commit_list_insert_by_date((struct commit *)object, list);
 825         return 0;
 826 }
 827
 828 static int get_sha1_oneline(const char *prefix, unsigned char *sha1,
 829                             struct commit_list *list)
 830 {
 831         struct commit_list *backup = NULL, *l;
 832         int found = 0;
 833         regex_t regex;
 834
 835         if (prefix[0] == '!') {
 836                 if (prefix[1] != '!')
 837                         die ("Invalid search pattern: %s", prefix);
 838                 prefix++;
 839         }
 840
 841         if (regcomp(&regex, prefix, REG_EXTENDED))
 842                 die("Invalid search pattern: %s", prefix);
 843
 844         for (l = list; l; l = l->next) {
 845                 l->item->object.flags |= ONELINE_SEEN;
 846                 commit_list_insert(l->item, &backup);
 847         }
 848         while (list) {
 849                 char *p, *to_free = NULL;
 850                 struct commit *commit;
 851                 enum object_type type;
 852                 unsigned long size;
 853                 int matches;
 854
 855                 commit = pop_most_recent_commit(&list, ONELINE_SEEN);
 856                 if (!parse_object(commit->object.sha1))
 857                         continue;
 858                 if (commit->buffer)
 859                         p = commit->buffer;
 860                 else {
 861                         p = read_sha1_file(commit->object.sha1, &type, &size);
 862                         if (!p)
 863                                 continue;
 864                         to_free = p;
 865                 }
 866
 867                 p = strstr(p, "\n\n");
 868                 matches = p && !regexec(&regex, p + 2, 0, NULL, 0);
 869                 free(to_free);
 870
 871                 if (matches) {
 872                         hashcpy(sha1, commit->object.sha1);
 873                         found = 1;
 874                         break;
 875                 }
 876         }
 877         regfree(&regex);
 878         free_commit_list(list);
 879         for (l = backup; l; l = l->next)
 880                 clear_commit_marks(l->item, ONELINE_SEEN);
 881         free_commit_list(backup);
 882         return found ? 0 : -1;
 883 }
 884
 885 struct grab_nth_branch_switch_cbdata {
 886         int remaining;
 887         struct strbuf buf;
 888 };
 889
 890 static int grab_nth_branch_switch(unsigned char *osha1, unsigned char *nsha1,
 891                                   const char *email, unsigned long timestamp, int tz,
 892                                   const char *message, void *cb_data)
 893 {
 894         struct grab_nth_branch_switch_cbdata *cb = cb_data;
 895         const char *match = NULL, *target = NULL;
 896         size_t len;
 897
 898         if (!prefixcmp(message, "checkout: moving from ")) {
 899                 match = message + strlen("checkout: moving from ");
 900                 target = strstr(match, " to ");
 901         }
 902
 903         if (!match || !target)
 904                 return 0;
 905         if (--(cb->remaining) == 0) {
 906                 len = target - match;
 907                 strbuf_reset(&cb->buf);
 908                 strbuf_add(&cb->buf, match, len);
 909                 return 1; /* we are done */
 910         }
 911         return 0;
 912 }
 913
 914 /*
 915  * Parse @{-N} syntax, return the number of characters parsed
 916  * if successful; otherwise signal an error with negative value.
 917  */
 918 static int interpret_nth_prior_checkout(const char *name, struct strbuf *buf)
 919 {
 920         long nth;
 921         int retval;
 922         struct grab_nth_branch_switch_cbdata cb;
 923         const char *brace;
 924         char *num_end;
 925
 926         if (name[0] != '@' || name[1] != '{' || name[2] != '-')
 927                 return -1;
 928         brace = strchr(name, '}');
 929         if (!brace)
 930                 return -1;
 931         nth = strtol(name + 3, &num_end, 10);
 932         if (num_end != brace)
 933                 return -1;
 934         if (nth <= 0)
 935                 return -1;
 936         cb.remaining = nth;
 937         strbuf_init(&cb.buf, 20);
 938
 939         retval = 0;
 940         if (0 < for_each_reflog_ent_reverse("HEAD", grab_nth_branch_switch, &cb)) {
 941                 strbuf_reset(buf);
 942                 strbuf_add(buf, cb.buf.buf, cb.buf.len);
 943                 retval = brace - name + 1;
 944         }
 945
 946         strbuf_release(&cb.buf);
 947         return retval;
 948 }
 949
 950 int get_sha1_mb(const char *name, unsigned char *sha1)
 951 {
 952         struct commit *one, *two;
 953         struct commit_list *mbs;
 954         unsigned char sha1_tmp[20];
 955         const char *dots;
 956         int st;
 957
 958         dots = strstr(name, "...");
 959         if (!dots)
 960                 return get_sha1(name, sha1);
 961         if (dots == name)
 962                 st = get_sha1("HEAD", sha1_tmp);
 963         else {
 964                 struct strbuf sb;
 965                 strbuf_init(&sb, dots - name);
 966                 strbuf_add(&sb, name, dots - name);
 967                 st = get_sha1_committish(sb.buf, sha1_tmp);
 968                 strbuf_release(&sb);
 969         }
 970         if (st)
 971                 return st;
 972         one = lookup_commit_reference_gently(sha1_tmp, 0);
 973         if (!one)
 974                 return -1;
 975
 976         if (get_sha1_committish(dots[3] ? (dots + 3) : "HEAD", sha1_tmp))
 977                 return -1;
 978         two = lookup_commit_reference_gently(sha1_tmp, 0);
 979         if (!two)
 980                 return -1;
 981         mbs = get_merge_bases(one, two, 1);
 982         if (!mbs || mbs->next)
 983                 st = -1;
 984         else {
 985                 st = 0;
 986                 hashcpy(sha1, mbs->item->object.sha1);
 987         }
 988         free_commit_list(mbs);
 989         return st;
 990 }
 991
 992 /*
 993  * This reads short-hand syntax that not only evaluates to a commit
 994  * object name, but also can act as if the end user spelled the name
 995  * of the branch from the command line.
 996  *
 997  * - "@{-N}" finds the name of the Nth previous branch we were on, and
 998  *   places the name of the branch in the given buf and returns the
 999  *   number of characters parsed if successful.
1000  *
1001  * - "<branch>@{upstream}" finds the name of the other ref that
1002  *   <branch> is configured to merge with (missing <branch> defaults
1003  *   to the current branch), and places the name of the branch in the
1004  *   given buf and returns the number of characters parsed if
1005  *   successful.
1006  *
1007  * If the input is not of the accepted format, it returns a negative
1008  * number to signal an error.
1009  *
1010  * If the input was ok but there are not N branch switches in the
1011  * reflog, it returns 0.
1012  */
1013 int interpret_branch_name(const char *name, struct strbuf *buf)
1014 {
1015         char *cp;
1016         struct branch *upstream;
1017         int namelen = strlen(name);
1018         int len = interpret_nth_prior_checkout(name, buf);
1019         int tmp_len;
1020
1021         if (!len)
1022                 return len; /* syntax Ok, not enough switches */
1023         if (0 < len && len == namelen)
1024                 return len; /* consumed all */
1025         else if (0 < len) {
1026                 /* we have extra data, which might need further processing */
1027                 struct strbuf tmp = STRBUF_INIT;
1028                 int used = buf->len;
1029                 int ret;
1030
1031                 strbuf_add(buf, name + len, namelen - len);
1032                 ret = interpret_branch_name(buf->buf, &tmp);
1033                 /* that data was not interpreted, remove our cruft */
1034                 if (ret < 0) {
1035                         strbuf_setlen(buf, used);
1036                         return len;
1037                 }
1038                 strbuf_reset(buf);
1039                 strbuf_addbuf(buf, &tmp);
1040                 strbuf_release(&tmp);
1041                 /* tweak for size of {-N} versus expanded ref name */
1042                 return ret - used + len;
1043         }
1044
1045         cp = strchr(name, '@');
1046         if (!cp)
1047                 return -1;
1048         tmp_len = upstream_mark(cp, namelen - (cp - name));
1049         if (!tmp_len)
1050                 return -1;
1051         len = cp + tmp_len - name;
1052         cp = xstrndup(name, cp - name);
1053         upstream = branch_get(*cp ? cp : NULL);
1054         /*
1055          * Upstream can be NULL only if cp refers to HEAD and HEAD
1056          * points to something different than a branch.
1057          */
1058         if (!upstream)
1059                 return error(_("HEAD does not point to a branch"));
1060         if (!upstream->merge || !upstream->merge[0]->dst) {
1061                 if (!ref_exists(upstream->refname))
1062                         return error(_("No such branch: '%s'"), cp);
1063                 if (!upstream->merge)
1064                         return error(_("No upstream configured for branch '%s'"),
1065                                      upstream->name);
1066                 return error(
1067                         _("Upstream branch '%s' not stored as a remote-tracking branch"),
1068                         upstream->merge[0]->src);
1069         }
1070         free(cp);
1071         cp = shorten_unambiguous_ref(upstream->merge[0]->dst, 0);
1072         strbuf_reset(buf);
1073         strbuf_addstr(buf, cp);
1074         free(cp);
1075         return len;
1076 }
1077
1078 int strbuf_branchname(struct strbuf *sb, const char *name)
1079 {
1080         int len = strlen(name);
1081         if (interpret_branch_name(name, sb) == len)
1082                 return 0;
1083         strbuf_add(sb, name, len);
1084         return len;
1085 }
1086
1087 int strbuf_check_branch_ref(struct strbuf *sb, const char *name)
1088 {
1089         strbuf_branchname(sb, name);
1090         if (name[0] == '-')
1091                 return -1;
1092         strbuf_splice(sb, 0, 0, "refs/heads/", 11);
1093         return check_refname_format(sb->buf, 0);
1094 }
1095
1096 /*
1097  * This is like "get_sha1_basic()", except it allows "sha1 expressions",
1098  * notably "xyz^" for "parent of xyz"
1099  */
1100 int get_sha1(const char *name, unsigned char *sha1)
1101 {
1102         struct object_context unused;
1103         return get_sha1_with_context(name, 0, sha1, &unused);
1104 }
1105
1106 /*
1107  * Many callers know that the user meant to name a committish by
1108  * syntactical positions where the object name appears.  Calling this
1109  * function allows the machinery to disambiguate shorter-than-unique
1110  * abbreviated object names between committish and others.
1111  *
1112  * Note that this does NOT error out when the named object is not a
1113  * committish. It is merely to give a hint to the disambiguation
1114  * machinery.
1115  */
1116 int get_sha1_committish(const char *name, unsigned char *sha1)
1117 {
1118         struct object_context unused;
1119         return get_sha1_with_context(name, GET_SHA1_COMMITTISH,
1120                                      sha1, &unused);
1121 }
1122
1123 int get_sha1_treeish(const char *name, unsigned char *sha1)
1124 {
1125         struct object_context unused;
1126         return get_sha1_with_context(name, GET_SHA1_TREEISH,
1127                                      sha1, &unused);
1128 }
1129
1130 int get_sha1_commit(const char *name, unsigned char *sha1)
1131 {
1132         struct object_context unused;
1133         return get_sha1_with_context(name, GET_SHA1_COMMIT,
1134                                      sha1, &unused);
1135 }
1136
1137 int get_sha1_tree(const char *name, unsigned char *sha1)
1138 {
1139         struct object_context unused;
1140         return get_sha1_with_context(name, GET_SHA1_TREE,
1141                                      sha1, &unused);
1142 }
1143
1144 int get_sha1_blob(const char *name, unsigned char *sha1)
1145 {
1146         struct object_context unused;
1147         return get_sha1_with_context(name, GET_SHA1_BLOB,
1148                                      sha1, &unused);
1149 }
1150
1151 /* Must be called only when object_name:filename doesn't exist. */
1152 static void diagnose_invalid_sha1_path(const char *prefix,
1153                                        const char *filename,
1154                                        const unsigned char *tree_sha1,
1155                                        const char *object_name,
1156                                        int object_name_len)
1157 {
1158         struct stat st;
1159         unsigned char sha1[20];
1160         unsigned mode;
1161
1162         if (!prefix)
1163                 prefix = "";
1164
1165         if (!lstat(filename, &st))
1166                 die("Path '%s' exists on disk, but not in '%.*s'.",
1167                     filename, object_name_len, object_name);
1168         if (errno == ENOENT || errno == ENOTDIR) {
1169                 char *fullname = xmalloc(strlen(filename)
1170                                              + strlen(prefix) + 1);
1171                 strcpy(fullname, prefix);
1172                 strcat(fullname, filename);
1173
1174                 if (!get_tree_entry(tree_sha1, fullname,
1175                                     sha1, &mode)) {
1176                         die("Path '%s' exists, but not '%s'.\n"
1177                             "Did you mean '%.*s:%s' aka '%.*s:./%s'?",
1178                             fullname,
1179                             filename,
1180                             object_name_len, object_name,
1181                             fullname,
1182                             object_name_len, object_name,
1183                             filename);
1184                 }
1185                 die("Path '%s' does not exist in '%.*s'",
1186                     filename, object_name_len, object_name);
1187         }
1188 }
1189
1190 /* Must be called only when :stage:filename doesn't exist. */
1191 static void diagnose_invalid_index_path(int stage,
1192                                         const char *prefix,
1193                                         const char *filename)
1194 {
1195         struct stat st;
1196         struct cache_entry *ce;
1197         int pos;
1198         unsigned namelen = strlen(filename);
1199         unsigned fullnamelen;
1200         char *fullname;
1201
1202         if (!prefix)
1203                 prefix = "";
1204
1205         /* Wrong stage number? */
1206         pos = cache_name_pos(filename, namelen);
1207         if (pos < 0)
1208                 pos = -pos - 1;
1209         if (pos < active_nr) {
1210                 ce = active_cache[pos];
1211                 if (ce_namelen(ce) == namelen &&
1212                     !memcmp(ce->name, filename, namelen))
1213                         die("Path '%s' is in the index, but not at stage %d.\n"
1214                             "Did you mean ':%d:%s'?",
1215                             filename, stage,
1216                             ce_stage(ce), filename);
1217         }
1218
1219         /* Confusion between relative and absolute filenames? */
1220         fullnamelen = namelen + strlen(prefix);
1221         fullname = xmalloc(fullnamelen + 1);
1222         strcpy(fullname, prefix);
1223         strcat(fullname, filename);
1224         pos = cache_name_pos(fullname, fullnamelen);
1225         if (pos < 0)
1226                 pos = -pos - 1;
1227         if (pos < active_nr) {
1228                 ce = active_cache[pos];
1229                 if (ce_namelen(ce) == fullnamelen &&
1230                     !memcmp(ce->name, fullname, fullnamelen))
1231                         die("Path '%s' is in the index, but not '%s'.\n"
1232                             "Did you mean ':%d:%s' aka ':%d:./%s'?",
1233                             fullname, filename,
1234                             ce_stage(ce), fullname,
1235                             ce_stage(ce), filename);
1236         }
1237
1238         if (!lstat(filename, &st))
1239                 die("Path '%s' exists on disk, but not in the index.", filename);
1240         if (errno == ENOENT || errno == ENOTDIR)
1241                 die("Path '%s' does not exist (neither on disk nor in the index).",
1242                     filename);
1243
1244         free(fullname);
1245 }
1246
1247
1248 static char *resolve_relative_path(const char *rel)
1249 {
1250         if (prefixcmp(rel, "./") && prefixcmp(rel, "../"))
1251                 return NULL;
1252
1253         if (!startup_info)
1254                 die("BUG: startup_info struct is not initialized.");
1255
1256         if (!is_inside_work_tree())
1257                 die("relative path syntax can't be used outside working tree.");
1258
1259         /* die() inside prefix_path() if resolved path is outside worktree */
1260         return prefix_path(startup_info->prefix,
1261                            startup_info->prefix ? strlen(startup_info->prefix) : 0,
1262                            rel);
1263 }
1264
1265 static int get_sha1_with_context_1(const char *name,
1266                                    unsigned flags,
1267                                    const char *prefix,
1268                                    unsigned char *sha1,
1269                                    struct object_context *oc)
1270 {
1271         int ret, bracket_depth;
1272         int namelen = strlen(name);
1273         const char *cp;
1274         int only_to_die = flags & GET_SHA1_ONLY_TO_DIE;
1275
1276         memset(oc, 0, sizeof(*oc));
1277         oc->mode = S_IFINVALID;
1278         ret = get_sha1_1(name, namelen, sha1, flags);
1279         if (!ret)
1280                 return ret;
1281         /*
1282          * sha1:path --> object name of path in ent sha1
1283          * :path -> object name of absolute path in index
1284          * :./path -> object name of path relative to cwd in index
1285          * :[0-3]:path -> object name of path in index at stage
1286          * :/foo -> recent commit matching foo
1287          */
1288         if (name[0] == ':') {
1289                 int stage = 0;
1290                 struct cache_entry *ce;
1291                 char *new_path = NULL;
1292                 int pos;
1293                 if (!only_to_die && namelen > 2 && name[1] == '/') {
1294                         struct commit_list *list = NULL;
1295                         for_each_ref(handle_one_ref, &list);
1296                         return get_sha1_oneline(name + 2, sha1, list);
1297                 }
1298                 if (namelen < 3 ||
1299                     name[2] != ':' ||
1300                     name[1] < '0' || '3' < name[1])
1301                         cp = name + 1;
1302                 else {
1303                         stage = name[1] - '0';
1304                         cp = name + 3;
1305                 }
1306                 new_path = resolve_relative_path(cp);
1307                 if (!new_path) {
1308                         namelen = namelen - (cp - name);
1309                 } else {
1310                         cp = new_path;
1311                         namelen = strlen(cp);
1312                 }
1313
1314                 strncpy(oc->path, cp,
1315                         sizeof(oc->path));
1316                 oc->path[sizeof(oc->path)-1] = '\0';
1317
1318                 if (!active_cache)
1319                         read_cache();
1320                 pos = cache_name_pos(cp, namelen);
1321                 if (pos < 0)
1322                         pos = -pos - 1;
1323                 while (pos < active_nr) {
1324                         ce = active_cache[pos];
1325                         if (ce_namelen(ce) != namelen ||
1326                             memcmp(ce->name, cp, namelen))
1327                                 break;
1328                         if (ce_stage(ce) == stage) {
1329                                 hashcpy(sha1, ce->sha1);
1330                                 oc->mode = ce->ce_mode;
1331                                 free(new_path);
1332                                 return 0;
1333                         }
1334                         pos++;
1335                 }
1336                 if (only_to_die && name[1] && name[1] != '/')
1337                         diagnose_invalid_index_path(stage, prefix, cp);
1338                 free(new_path);
1339                 return -1;
1340         }
1341         for (cp = name, bracket_depth = 0; *cp; cp++) {
1342                 if (*cp == '{')
1343                         bracket_depth++;
1344                 else if (bracket_depth && *cp == '}')
1345                         bracket_depth--;
1346                 else if (!bracket_depth && *cp == ':')
1347                         break;
1348         }
1349         if (*cp == ':') {
1350                 unsigned char tree_sha1[20];
1351                 int len = cp - name;
1352                 if (!get_sha1_1(name, len, tree_sha1, GET_SHA1_TREEISH)) {
1353                         const char *filename = cp+1;
1354                         char *new_filename = NULL;
1355
1356                         new_filename = resolve_relative_path(filename);
1357                         if (new_filename)
1358                                 filename = new_filename;
1359                         ret = get_tree_entry(tree_sha1, filename, sha1, &oc->mode);
1360                         if (ret && only_to_die) {
1361                                 diagnose_invalid_sha1_path(prefix, filename,
1362                                                            tree_sha1,
1363                                                            name, len);
1364                         }
1365                         hashcpy(oc->tree, tree_sha1);
1366                         strncpy(oc->path, filename,
1367                                 sizeof(oc->path));
1368                         oc->path[sizeof(oc->path)-1] = '\0';
1369
1370                         free(new_filename);
1371                         return ret;
1372                 } else {
1373                         if (only_to_die)
1374                                 die("Invalid object name '%.*s'.", len, name);
1375                 }
1376         }
1377         return ret;
1378 }
1379
1380 /*
1381  * Call this function when you know "name" given by the end user must
1382  * name an object but it doesn't; the function _may_ die with a better
1383  * diagnostic message than "no such object 'name'", e.g. "Path 'doc' does not
1384  * exist in 'HEAD'" when given "HEAD:doc", or it may return in which case
1385  * you have a chance to diagnose the error further.
1386  */
1387 void maybe_die_on_misspelt_object_name(const char *name, const char *prefix)
1388 {
1389         struct object_context oc;
1390         unsigned char sha1[20];
1391         get_sha1_with_context_1(name, GET_SHA1_ONLY_TO_DIE, prefix, sha1, &oc);
1392 }
1393
1394 int get_sha1_with_context(const char *str, unsigned flags, unsigned char *sha1, struct object_context *orc)
1395 {
1396         return get_sha1_with_context_1(str, flags, NULL, sha1, orc);
1397 }