git.oblomov.eu Git - git/blob - refs.c

   1 /*
   2  * The backend-independent part of the reference module.
   3  */
   4
   5 #include "cache.h"
   6 #include "config.h"
   7 #include "hashmap.h"
   8 #include "lockfile.h"
   9 #include "iterator.h"
  10 #include "refs.h"
  11 #include "refs/refs-internal.h"
  12 #include "object.h"
  13 #include "tag.h"
  14 #include "submodule.h"
  15 #include "worktree.h"
  16
  17 /*
  18  * List of all available backends
  19  */
  20 static struct ref_storage_be *refs_backends = &refs_be_files;
  21
  22 static struct ref_storage_be *find_ref_storage_backend(const char *name)
  23 {
  24         struct ref_storage_be *be;
  25         for (be = refs_backends; be; be = be->next)
  26                 if (!strcmp(be->name, name))
  27                         return be;
  28         return NULL;
  29 }
  30
  31 int ref_storage_backend_exists(const char *name)
  32 {
  33         return find_ref_storage_backend(name) != NULL;
  34 }
  35
  36 /*
  37  * How to handle various characters in refnames:
  38  * 0: An acceptable character for refs
  39  * 1: End-of-component
  40  * 2: ., look for a preceding . to reject .. in refs
  41  * 3: {, look for a preceding @ to reject @{ in refs
  42  * 4: A bad character: ASCII control characters, and
  43  *    ":", "?", "[", "\", "^", "~", SP, or TAB
  44  * 5: *, reject unless REFNAME_REFSPEC_PATTERN is set
  45  */
  46 static unsigned char refname_disposition[256] = {
  47         1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  48         4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
  49         4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 0, 2, 1,
  50         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
  51         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  52         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
  53         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  54         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
  55 };
  56
  57 /*
  58  * Try to read one refname component from the front of refname.
  59  * Return the length of the component found, or -1 if the component is
  60  * not legal.  It is legal if it is something reasonable to have under
  61  * ".git/refs/"; We do not like it if:
  62  *
  63  * - any path component of it begins with ".", or
  64  * - it has double dots "..", or
  65  * - it has ASCII control characters, or
  66  * - it has ":", "?", "[", "\", "^", "~", SP, or TAB anywhere, or
  67  * - it has "*" anywhere unless REFNAME_REFSPEC_PATTERN is set, or
  68  * - it ends with a "/", or
  69  * - it ends with ".lock", or
  70  * - it contains a "@{" portion
  71  */
  72 static int check_refname_component(const char *refname, int *flags)
  73 {
  74         const char *cp;
  75         char last = '\0';
  76
  77         for (cp = refname; ; cp++) {
  78                 int ch = *cp & 255;
  79                 unsigned char disp = refname_disposition[ch];
  80                 switch (disp) {
  81                 case 1:
  82                         goto out;
  83                 case 2:
  84                         if (last == '.')
  85                                 return -1; /* Refname contains "..". */
  86                         break;
  87                 case 3:
  88                         if (last == '@')
  89                                 return -1; /* Refname contains "@{". */
  90                         break;
  91                 case 4:
  92                         return -1;
  93                 case 5:
  94                         if (!(*flags & REFNAME_REFSPEC_PATTERN))
  95                                 return -1; /* refspec can't be a pattern */
  96
  97                         /*
  98                          * Unset the pattern flag so that we only accept
  99                          * a single asterisk for one side of refspec.
 100                          */
 101                         *flags &= ~ REFNAME_REFSPEC_PATTERN;
 102                         break;
 103                 }
 104                 last = ch;
 105         }
 106 out:
 107         if (cp == refname)
 108                 return 0; /* Component has zero length. */
 109         if (refname[0] == '.')
 110                 return -1; /* Component starts with '.'. */
 111         if (cp - refname >= LOCK_SUFFIX_LEN &&
 112             !memcmp(cp - LOCK_SUFFIX_LEN, LOCK_SUFFIX, LOCK_SUFFIX_LEN))
 113                 return -1; /* Refname ends with ".lock". */
 114         return cp - refname;
 115 }
 116
 117 int check_refname_format(const char *refname, int flags)
 118 {
 119         int component_len, component_count = 0;
 120
 121         if (!strcmp(refname, "@"))
 122                 /* Refname is a single character '@'. */
 123                 return -1;
 124
 125         while (1) {
 126                 /* We are at the start of a path component. */
 127                 component_len = check_refname_component(refname, &flags);
 128                 if (component_len <= 0)
 129                         return -1;
 130
 131                 component_count++;
 132                 if (refname[component_len] == '\0')
 133                         break;
 134                 /* Skip to next component. */
 135                 refname += component_len + 1;
 136         }
 137
 138         if (refname[component_len - 1] == '.')
 139                 return -1; /* Refname ends with '.'. */
 140         if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
 141                 return -1; /* Refname has only one component. */
 142         return 0;
 143 }
 144
 145 int refname_is_safe(const char *refname)
 146 {
 147         const char *rest;
 148
 149         if (skip_prefix(refname, "refs/", &rest)) {
 150                 char *buf;
 151                 int result;
 152                 size_t restlen = strlen(rest);
 153
 154                 /* rest must not be empty, or start or end with "/" */
 155                 if (!restlen || *rest == '/' || rest[restlen - 1] == '/')
 156                         return 0;
 157
 158                 /*
 159                  * Does the refname try to escape refs/?
 160                  * For example: refs/foo/../bar is safe but refs/foo/../../bar
 161                  * is not.
 162                  */
 163                 buf = xmallocz(restlen);
 164                 result = !normalize_path_copy(buf, rest) && !strcmp(buf, rest);
 165                 free(buf);
 166                 return result;
 167         }
 168
 169         do {
 170                 if (!isupper(*refname) && *refname != '_')
 171                         return 0;
 172                 refname++;
 173         } while (*refname);
 174         return 1;
 175 }
 176
 177 /*
 178  * Return true if refname, which has the specified oid and flags, can
 179  * be resolved to an object in the database. If the referred-to object
 180  * does not exist, emit a warning and return false.
 181  */
 182 int ref_resolves_to_object(const char *refname,
 183                            const struct object_id *oid,
 184                            unsigned int flags)
 185 {
 186         if (flags & REF_ISBROKEN)
 187                 return 0;
 188         if (!has_sha1_file(oid->hash)) {
 189                 error("%s does not point to a valid object!", refname);
 190                 return 0;
 191         }
 192         return 1;
 193 }
 194
 195 char *refs_resolve_refdup(struct ref_store *refs,
 196                           const char *refname, int resolve_flags,
 197                           unsigned char *sha1, int *flags)
 198 {
 199         const char *result;
 200
 201         result = refs_resolve_ref_unsafe(refs, refname, resolve_flags,
 202                                          sha1, flags);
 203         return xstrdup_or_null(result);
 204 }
 205
 206 char *resolve_refdup(const char *refname, int resolve_flags,
 207                      unsigned char *sha1, int *flags)
 208 {
 209         return refs_resolve_refdup(get_main_ref_store(),
 210                                    refname, resolve_flags,
 211                                    sha1, flags);
 212 }
 213
 214 /* The argument to filter_refs */
 215 struct ref_filter {
 216         const char *pattern;
 217         each_ref_fn *fn;
 218         void *cb_data;
 219 };
 220
 221 int refs_read_ref_full(struct ref_store *refs, const char *refname,
 222                        int resolve_flags, unsigned char *sha1, int *flags)
 223 {
 224         if (refs_resolve_ref_unsafe(refs, refname, resolve_flags, sha1, flags))
 225                 return 0;
 226         return -1;
 227 }
 228
 229 int read_ref_full(const char *refname, int resolve_flags, unsigned char *sha1, int *flags)
 230 {
 231         return refs_read_ref_full(get_main_ref_store(), refname,
 232                                   resolve_flags, sha1, flags);
 233 }
 234
 235 int read_ref(const char *refname, unsigned char *sha1)
 236 {
 237         return read_ref_full(refname, RESOLVE_REF_READING, sha1, NULL);
 238 }
 239
 240 int ref_exists(const char *refname)
 241 {
 242         unsigned char sha1[20];
 243         return !!resolve_ref_unsafe(refname, RESOLVE_REF_READING, sha1, NULL);
 244 }
 245
 246 static int filter_refs(const char *refname, const struct object_id *oid,
 247                            int flags, void *data)
 248 {
 249         struct ref_filter *filter = (struct ref_filter *)data;
 250
 251         if (wildmatch(filter->pattern, refname, 0))
 252                 return 0;
 253         return filter->fn(refname, oid, flags, filter->cb_data);
 254 }
 255
 256 enum peel_status peel_object(const unsigned char *name, unsigned char *sha1)
 257 {
 258         struct object *o = lookup_unknown_object(name);
 259
 260         if (o->type == OBJ_NONE) {
 261                 int type = sha1_object_info(name, NULL);
 262                 if (type < 0 || !object_as_type(o, type, 0))
 263                         return PEEL_INVALID;
 264         }
 265
 266         if (o->type != OBJ_TAG)
 267                 return PEEL_NON_TAG;
 268
 269         o = deref_tag_noverify(o);
 270         if (!o)
 271                 return PEEL_INVALID;
 272
 273         hashcpy(sha1, o->oid.hash);
 274         return PEEL_PEELED;
 275 }
 276
 277 struct warn_if_dangling_data {
 278         FILE *fp;
 279         const char *refname;
 280         const struct string_list *refnames;
 281         const char *msg_fmt;
 282 };
 283
 284 static int warn_if_dangling_symref(const char *refname, const struct object_id *oid,
 285                                    int flags, void *cb_data)
 286 {
 287         struct warn_if_dangling_data *d = cb_data;
 288         const char *resolves_to;
 289         struct object_id junk;
 290
 291         if (!(flags & REF_ISSYMREF))
 292                 return 0;
 293
 294         resolves_to = resolve_ref_unsafe(refname, 0, junk.hash, NULL);
 295         if (!resolves_to
 296             || (d->refname
 297                 ? strcmp(resolves_to, d->refname)
 298                 : !string_list_has_string(d->refnames, resolves_to))) {
 299                 return 0;
 300         }
 301
 302         fprintf(d->fp, d->msg_fmt, refname);
 303         fputc('\n', d->fp);
 304         return 0;
 305 }
 306
 307 void warn_dangling_symref(FILE *fp, const char *msg_fmt, const char *refname)
 308 {
 309         struct warn_if_dangling_data data;
 310
 311         data.fp = fp;
 312         data.refname = refname;
 313         data.refnames = NULL;
 314         data.msg_fmt = msg_fmt;
 315         for_each_rawref(warn_if_dangling_symref, &data);
 316 }
 317
 318 void warn_dangling_symrefs(FILE *fp, const char *msg_fmt, const struct string_list *refnames)
 319 {
 320         struct warn_if_dangling_data data;
 321
 322         data.fp = fp;
 323         data.refname = NULL;
 324         data.refnames = refnames;
 325         data.msg_fmt = msg_fmt;
 326         for_each_rawref(warn_if_dangling_symref, &data);
 327 }
 328
 329 int refs_for_each_tag_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 330 {
 331         return refs_for_each_ref_in(refs, "refs/tags/", fn, cb_data);
 332 }
 333
 334 int for_each_tag_ref(each_ref_fn fn, void *cb_data)
 335 {
 336         return refs_for_each_tag_ref(get_main_ref_store(), fn, cb_data);
 337 }
 338
 339 int for_each_tag_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
 340 {
 341         return refs_for_each_tag_ref(get_submodule_ref_store(submodule),
 342                                      fn, cb_data);
 343 }
 344
 345 int refs_for_each_branch_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 346 {
 347         return refs_for_each_ref_in(refs, "refs/heads/", fn, cb_data);
 348 }
 349
 350 int for_each_branch_ref(each_ref_fn fn, void *cb_data)
 351 {
 352         return refs_for_each_branch_ref(get_main_ref_store(), fn, cb_data);
 353 }
 354
 355 int for_each_branch_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
 356 {
 357         return refs_for_each_branch_ref(get_submodule_ref_store(submodule),
 358                                         fn, cb_data);
 359 }
 360
 361 int refs_for_each_remote_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
 362 {
 363         return refs_for_each_ref_in(refs, "refs/remotes/", fn, cb_data);
 364 }
 365
 366 int for_each_remote_ref(each_ref_fn fn, void *cb_data)
 367 {
 368         return refs_for_each_remote_ref(get_main_ref_store(), fn, cb_data);
 369 }
 370
 371 int for_each_remote_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
 372 {
 373         return refs_for_each_remote_ref(get_submodule_ref_store(submodule),
 374                                         fn, cb_data);
 375 }
 376
 377 int head_ref_namespaced(each_ref_fn fn, void *cb_data)
 378 {
 379         struct strbuf buf = STRBUF_INIT;
 380         int ret = 0;
 381         struct object_id oid;
 382         int flag;
 383
 384         strbuf_addf(&buf, "%sHEAD", get_git_namespace());
 385         if (!read_ref_full(buf.buf, RESOLVE_REF_READING, oid.hash, &flag))
 386                 ret = fn(buf.buf, &oid, flag, cb_data);
 387         strbuf_release(&buf);
 388
 389         return ret;
 390 }
 391
 392 int for_each_glob_ref_in(each_ref_fn fn, const char *pattern,
 393         const char *prefix, void *cb_data)
 394 {
 395         struct strbuf real_pattern = STRBUF_INIT;
 396         struct ref_filter filter;
 397         int ret;
 398
 399         if (!prefix && !starts_with(pattern, "refs/"))
 400                 strbuf_addstr(&real_pattern, "refs/");
 401         else if (prefix)
 402                 strbuf_addstr(&real_pattern, prefix);
 403         strbuf_addstr(&real_pattern, pattern);
 404
 405         if (!has_glob_specials(pattern)) {
 406                 /* Append implied '/' '*' if not present. */
 407                 strbuf_complete(&real_pattern, '/');
 408                 /* No need to check for '*', there is none. */
 409                 strbuf_addch(&real_pattern, '*');
 410         }
 411
 412         filter.pattern = real_pattern.buf;
 413         filter.fn = fn;
 414         filter.cb_data = cb_data;
 415         ret = for_each_ref(filter_refs, &filter);
 416
 417         strbuf_release(&real_pattern);
 418         return ret;
 419 }
 420
 421 int for_each_glob_ref(each_ref_fn fn, const char *pattern, void *cb_data)
 422 {
 423         return for_each_glob_ref_in(fn, pattern, NULL, cb_data);
 424 }
 425
 426 const char *prettify_refname(const char *name)
 427 {
 428         if (skip_prefix(name, "refs/heads/", &name) ||
 429             skip_prefix(name, "refs/tags/", &name) ||
 430             skip_prefix(name, "refs/remotes/", &name))
 431                 ; /* nothing */
 432         return name;
 433 }
 434
 435 static const char *ref_rev_parse_rules[] = {
 436         "%.*s",
 437         "refs/%.*s",
 438         "refs/tags/%.*s",
 439         "refs/heads/%.*s",
 440         "refs/remotes/%.*s",
 441         "refs/remotes/%.*s/HEAD",
 442         NULL
 443 };
 444
 445 int refname_match(const char *abbrev_name, const char *full_name)
 446 {
 447         const char **p;
 448         const int abbrev_name_len = strlen(abbrev_name);
 449
 450         for (p = ref_rev_parse_rules; *p; p++) {
 451                 if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
 452                         return 1;
 453                 }
 454         }
 455
 456         return 0;
 457 }
 458
 459 /*
 460  * *string and *len will only be substituted, and *string returned (for
 461  * later free()ing) if the string passed in is a magic short-hand form
 462  * to name a branch.
 463  */
 464 static char *substitute_branch_name(const char **string, int *len)
 465 {
 466         struct strbuf buf = STRBUF_INIT;
 467         int ret = interpret_branch_name(*string, *len, &buf, 0);
 468
 469         if (ret == *len) {
 470                 size_t size;
 471                 *string = strbuf_detach(&buf, &size);
 472                 *len = size;
 473                 return (char *)*string;
 474         }
 475
 476         return NULL;
 477 }
 478
 479 int dwim_ref(const char *str, int len, unsigned char *sha1, char **ref)
 480 {
 481         char *last_branch = substitute_branch_name(&str, &len);
 482         int   refs_found  = expand_ref(str, len, sha1, ref);
 483         free(last_branch);
 484         return refs_found;
 485 }
 486
 487 int expand_ref(const char *str, int len, unsigned char *sha1, char **ref)
 488 {
 489         const char **p, *r;
 490         int refs_found = 0;
 491         struct strbuf fullref = STRBUF_INIT;
 492
 493         *ref = NULL;
 494         for (p = ref_rev_parse_rules; *p; p++) {
 495                 unsigned char sha1_from_ref[20];
 496                 unsigned char *this_result;
 497                 int flag;
 498
 499                 this_result = refs_found ? sha1_from_ref : sha1;
 500                 strbuf_reset(&fullref);
 501                 strbuf_addf(&fullref, *p, len, str);
 502                 r = resolve_ref_unsafe(fullref.buf, RESOLVE_REF_READING,
 503                                        this_result, &flag);
 504                 if (r) {
 505                         if (!refs_found++)
 506                                 *ref = xstrdup(r);
 507                         if (!warn_ambiguous_refs)
 508                                 break;
 509                 } else if ((flag & REF_ISSYMREF) && strcmp(fullref.buf, "HEAD")) {
 510                         warning("ignoring dangling symref %s.", fullref.buf);
 511                 } else if ((flag & REF_ISBROKEN) && strchr(fullref.buf, '/')) {
 512                         warning("ignoring broken ref %s.", fullref.buf);
 513                 }
 514         }
 515         strbuf_release(&fullref);
 516         return refs_found;
 517 }
 518
 519 int dwim_log(const char *str, int len, unsigned char *sha1, char **log)
 520 {
 521         char *last_branch = substitute_branch_name(&str, &len);
 522         const char **p;
 523         int logs_found = 0;
 524         struct strbuf path = STRBUF_INIT;
 525
 526         *log = NULL;
 527         for (p = ref_rev_parse_rules; *p; p++) {
 528                 unsigned char hash[20];
 529                 const char *ref, *it;
 530
 531                 strbuf_reset(&path);
 532                 strbuf_addf(&path, *p, len, str);
 533                 ref = resolve_ref_unsafe(path.buf, RESOLVE_REF_READING,
 534                                          hash, NULL);
 535                 if (!ref)
 536                         continue;
 537                 if (reflog_exists(path.buf))
 538                         it = path.buf;
 539                 else if (strcmp(ref, path.buf) && reflog_exists(ref))
 540                         it = ref;
 541                 else
 542                         continue;
 543                 if (!logs_found++) {
 544                         *log = xstrdup(it);
 545                         hashcpy(sha1, hash);
 546                 }
 547                 if (!warn_ambiguous_refs)
 548                         break;
 549         }
 550         strbuf_release(&path);
 551         free(last_branch);
 552         return logs_found;
 553 }
 554
 555 static int is_per_worktree_ref(const char *refname)
 556 {
 557         return !strcmp(refname, "HEAD") ||
 558                 starts_with(refname, "refs/bisect/");
 559 }
 560
 561 static int is_pseudoref_syntax(const char *refname)
 562 {
 563         const char *c;
 564
 565         for (c = refname; *c; c++) {
 566                 if (!isupper(*c) && *c != '-' && *c != '_')
 567                         return 0;
 568         }
 569
 570         return 1;
 571 }
 572
 573 enum ref_type ref_type(const char *refname)
 574 {
 575         if (is_per_worktree_ref(refname))
 576                 return REF_TYPE_PER_WORKTREE;
 577         if (is_pseudoref_syntax(refname))
 578                 return REF_TYPE_PSEUDOREF;
 579        return REF_TYPE_NORMAL;
 580 }
 581
 582 long get_files_ref_lock_timeout_ms(void)
 583 {
 584         static int configured = 0;
 585
 586         /* The default timeout is 100 ms: */
 587         static int timeout_ms = 100;
 588
 589         if (!configured) {
 590                 git_config_get_int("core.filesreflocktimeout", &timeout_ms);
 591                 configured = 1;
 592         }
 593
 594         return timeout_ms;
 595 }
 596
 597 static int write_pseudoref(const char *pseudoref, const unsigned char *sha1,
 598                            const unsigned char *old_sha1, struct strbuf *err)
 599 {
 600         const char *filename;
 601         int fd;
 602         static struct lock_file lock;
 603         struct strbuf buf = STRBUF_INIT;
 604         int ret = -1;
 605
 606         strbuf_addf(&buf, "%s\n", sha1_to_hex(sha1));
 607
 608         filename = git_path("%s", pseudoref);
 609         fd = hold_lock_file_for_update_timeout(&lock, filename,
 610                                                LOCK_DIE_ON_ERROR,
 611                                                get_files_ref_lock_timeout_ms());
 612         if (fd < 0) {
 613                 strbuf_addf(err, "could not open '%s' for writing: %s",
 614                             filename, strerror(errno));
 615                 return -1;
 616         }
 617
 618         if (old_sha1) {
 619                 unsigned char actual_old_sha1[20];
 620
 621                 if (read_ref(pseudoref, actual_old_sha1))
 622                         die("could not read ref '%s'", pseudoref);
 623                 if (hashcmp(actual_old_sha1, old_sha1)) {
 624                         strbuf_addf(err, "unexpected sha1 when writing '%s'", pseudoref);
 625                         rollback_lock_file(&lock);
 626                         goto done;
 627                 }
 628         }
 629
 630         if (write_in_full(fd, buf.buf, buf.len) != buf.len) {
 631                 strbuf_addf(err, "could not write to '%s'", filename);
 632                 rollback_lock_file(&lock);
 633                 goto done;
 634         }
 635
 636         commit_lock_file(&lock);
 637         ret = 0;
 638 done:
 639         strbuf_release(&buf);
 640         return ret;
 641 }
 642
 643 static int delete_pseudoref(const char *pseudoref, const unsigned char *old_sha1)
 644 {
 645         static struct lock_file lock;
 646         const char *filename;
 647
 648         filename = git_path("%s", pseudoref);
 649
 650         if (old_sha1 && !is_null_sha1(old_sha1)) {
 651                 int fd;
 652                 unsigned char actual_old_sha1[20];
 653
 654                 fd = hold_lock_file_for_update_timeout(
 655                                 &lock, filename, LOCK_DIE_ON_ERROR,
 656                                 get_files_ref_lock_timeout_ms());
 657                 if (fd < 0)
 658                         die_errno(_("Could not open '%s' for writing"), filename);
 659                 if (read_ref(pseudoref, actual_old_sha1))
 660                         die("could not read ref '%s'", pseudoref);
 661                 if (hashcmp(actual_old_sha1, old_sha1)) {
 662                         warning("Unexpected sha1 when deleting %s", pseudoref);
 663                         rollback_lock_file(&lock);
 664                         return -1;
 665                 }
 666
 667                 unlink(filename);
 668                 rollback_lock_file(&lock);
 669         } else {
 670                 unlink(filename);
 671         }
 672
 673         return 0;
 674 }
 675
 676 int refs_delete_ref(struct ref_store *refs, const char *msg,
 677                     const char *refname,
 678                     const unsigned char *old_sha1,
 679                     unsigned int flags)
 680 {
 681         struct ref_transaction *transaction;
 682         struct strbuf err = STRBUF_INIT;
 683
 684         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
 685                 assert(refs == get_main_ref_store());
 686                 return delete_pseudoref(refname, old_sha1);
 687         }
 688
 689         transaction = ref_store_transaction_begin(refs, &err);
 690         if (!transaction ||
 691             ref_transaction_delete(transaction, refname, old_sha1,
 692                                    flags, msg, &err) ||
 693             ref_transaction_commit(transaction, &err)) {
 694                 error("%s", err.buf);
 695                 ref_transaction_free(transaction);
 696                 strbuf_release(&err);
 697                 return 1;
 698         }
 699         ref_transaction_free(transaction);
 700         strbuf_release(&err);
 701         return 0;
 702 }
 703
 704 int delete_ref(const char *msg, const char *refname,
 705                const unsigned char *old_sha1, unsigned int flags)
 706 {
 707         return refs_delete_ref(get_main_ref_store(), msg, refname,
 708                                old_sha1, flags);
 709 }
 710
 711 int copy_reflog_msg(char *buf, const char *msg)
 712 {
 713         char *cp = buf;
 714         char c;
 715         int wasspace = 1;
 716
 717         *cp++ = '\t';
 718         while ((c = *msg++)) {
 719                 if (wasspace && isspace(c))
 720                         continue;
 721                 wasspace = isspace(c);
 722                 if (wasspace)
 723                         c = ' ';
 724                 *cp++ = c;
 725         }
 726         while (buf < cp && isspace(cp[-1]))
 727                 cp--;
 728         *cp++ = '\n';
 729         return cp - buf;
 730 }
 731
 732 int should_autocreate_reflog(const char *refname)
 733 {
 734         switch (log_all_ref_updates) {
 735         case LOG_REFS_ALWAYS:
 736                 return 1;
 737         case LOG_REFS_NORMAL:
 738                 return starts_with(refname, "refs/heads/") ||
 739                         starts_with(refname, "refs/remotes/") ||
 740                         starts_with(refname, "refs/notes/") ||
 741                         !strcmp(refname, "HEAD");
 742         default:
 743                 return 0;
 744         }
 745 }
 746
 747 int is_branch(const char *refname)
 748 {
 749         return !strcmp(refname, "HEAD") || starts_with(refname, "refs/heads/");
 750 }
 751
 752 struct read_ref_at_cb {
 753         const char *refname;
 754         timestamp_t at_time;
 755         int cnt;
 756         int reccnt;
 757         unsigned char *sha1;
 758         int found_it;
 759
 760         unsigned char osha1[20];
 761         unsigned char nsha1[20];
 762         int tz;
 763         timestamp_t date;
 764         char **msg;
 765         timestamp_t *cutoff_time;
 766         int *cutoff_tz;
 767         int *cutoff_cnt;
 768 };
 769
 770 static int read_ref_at_ent(struct object_id *ooid, struct object_id *noid,
 771                 const char *email, timestamp_t timestamp, int tz,
 772                 const char *message, void *cb_data)
 773 {
 774         struct read_ref_at_cb *cb = cb_data;
 775
 776         cb->reccnt++;
 777         cb->tz = tz;
 778         cb->date = timestamp;
 779
 780         if (timestamp <= cb->at_time || cb->cnt == 0) {
 781                 if (cb->msg)
 782                         *cb->msg = xstrdup(message);
 783                 if (cb->cutoff_time)
 784                         *cb->cutoff_time = timestamp;
 785                 if (cb->cutoff_tz)
 786                         *cb->cutoff_tz = tz;
 787                 if (cb->cutoff_cnt)
 788                         *cb->cutoff_cnt = cb->reccnt - 1;
 789                 /*
 790                  * we have not yet updated cb->[n|o]sha1 so they still
 791                  * hold the values for the previous record.
 792                  */
 793                 if (!is_null_sha1(cb->osha1)) {
 794                         hashcpy(cb->sha1, noid->hash);
 795                         if (hashcmp(cb->osha1, noid->hash))
 796                                 warning("Log for ref %s has gap after %s.",
 797                                         cb->refname, show_date(cb->date, cb->tz, DATE_MODE(RFC2822)));
 798                 }
 799                 else if (cb->date == cb->at_time)
 800                         hashcpy(cb->sha1, noid->hash);
 801                 else if (hashcmp(noid->hash, cb->sha1))
 802                         warning("Log for ref %s unexpectedly ended on %s.",
 803                                 cb->refname, show_date(cb->date, cb->tz,
 804                                                        DATE_MODE(RFC2822)));
 805                 hashcpy(cb->osha1, ooid->hash);
 806                 hashcpy(cb->nsha1, noid->hash);
 807                 cb->found_it = 1;
 808                 return 1;
 809         }
 810         hashcpy(cb->osha1, ooid->hash);
 811         hashcpy(cb->nsha1, noid->hash);
 812         if (cb->cnt > 0)
 813                 cb->cnt--;
 814         return 0;
 815 }
 816
 817 static int read_ref_at_ent_oldest(struct object_id *ooid, struct object_id *noid,
 818                                   const char *email, timestamp_t timestamp,
 819                                   int tz, const char *message, void *cb_data)
 820 {
 821         struct read_ref_at_cb *cb = cb_data;
 822
 823         if (cb->msg)
 824                 *cb->msg = xstrdup(message);
 825         if (cb->cutoff_time)
 826                 *cb->cutoff_time = timestamp;
 827         if (cb->cutoff_tz)
 828                 *cb->cutoff_tz = tz;
 829         if (cb->cutoff_cnt)
 830                 *cb->cutoff_cnt = cb->reccnt;
 831         hashcpy(cb->sha1, ooid->hash);
 832         if (is_null_sha1(cb->sha1))
 833                 hashcpy(cb->sha1, noid->hash);
 834         /* We just want the first entry */
 835         return 1;
 836 }
 837
 838 int read_ref_at(const char *refname, unsigned int flags, timestamp_t at_time, int cnt,
 839                 unsigned char *sha1, char **msg,
 840                 timestamp_t *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
 841 {
 842         struct read_ref_at_cb cb;
 843
 844         memset(&cb, 0, sizeof(cb));
 845         cb.refname = refname;
 846         cb.at_time = at_time;
 847         cb.cnt = cnt;
 848         cb.msg = msg;
 849         cb.cutoff_time = cutoff_time;
 850         cb.cutoff_tz = cutoff_tz;
 851         cb.cutoff_cnt = cutoff_cnt;
 852         cb.sha1 = sha1;
 853
 854         for_each_reflog_ent_reverse(refname, read_ref_at_ent, &cb);
 855
 856         if (!cb.reccnt) {
 857                 if (flags & GET_OID_QUIETLY)
 858                         exit(128);
 859                 else
 860                         die("Log for %s is empty.", refname);
 861         }
 862         if (cb.found_it)
 863                 return 0;
 864
 865         for_each_reflog_ent(refname, read_ref_at_ent_oldest, &cb);
 866
 867         return 1;
 868 }
 869
 870 struct ref_transaction *ref_store_transaction_begin(struct ref_store *refs,
 871                                                     struct strbuf *err)
 872 {
 873         struct ref_transaction *tr;
 874         assert(err);
 875
 876         tr = xcalloc(1, sizeof(struct ref_transaction));
 877         tr->ref_store = refs;
 878         return tr;
 879 }
 880
 881 struct ref_transaction *ref_transaction_begin(struct strbuf *err)
 882 {
 883         return ref_store_transaction_begin(get_main_ref_store(), err);
 884 }
 885
 886 void ref_transaction_free(struct ref_transaction *transaction)
 887 {
 888         size_t i;
 889
 890         if (!transaction)
 891                 return;
 892
 893         switch (transaction->state) {
 894         case REF_TRANSACTION_OPEN:
 895         case REF_TRANSACTION_CLOSED:
 896                 /* OK */
 897                 break;
 898         case REF_TRANSACTION_PREPARED:
 899                 die("BUG: free called on a prepared reference transaction");
 900                 break;
 901         default:
 902                 die("BUG: unexpected reference transaction state");
 903                 break;
 904         }
 905
 906         for (i = 0; i < transaction->nr; i++) {
 907                 free(transaction->updates[i]->msg);
 908                 free(transaction->updates[i]);
 909         }
 910         free(transaction->updates);
 911         free(transaction);
 912 }
 913
 914 struct ref_update *ref_transaction_add_update(
 915                 struct ref_transaction *transaction,
 916                 const char *refname, unsigned int flags,
 917                 const unsigned char *new_sha1,
 918                 const unsigned char *old_sha1,
 919                 const char *msg)
 920 {
 921         struct ref_update *update;
 922
 923         if (transaction->state != REF_TRANSACTION_OPEN)
 924                 die("BUG: update called for transaction that is not open");
 925
 926         if ((flags & REF_ISPRUNING) && !(flags & REF_NODEREF))
 927                 die("BUG: REF_ISPRUNING set without REF_NODEREF");
 928
 929         FLEX_ALLOC_STR(update, refname, refname);
 930         ALLOC_GROW(transaction->updates, transaction->nr + 1, transaction->alloc);
 931         transaction->updates[transaction->nr++] = update;
 932
 933         update->flags = flags;
 934
 935         if (flags & REF_HAVE_NEW)
 936                 hashcpy(update->new_oid.hash, new_sha1);
 937         if (flags & REF_HAVE_OLD)
 938                 hashcpy(update->old_oid.hash, old_sha1);
 939         update->msg = xstrdup_or_null(msg);
 940         return update;
 941 }
 942
 943 int ref_transaction_update(struct ref_transaction *transaction,
 944                            const char *refname,
 945                            const unsigned char *new_sha1,
 946                            const unsigned char *old_sha1,
 947                            unsigned int flags, const char *msg,
 948                            struct strbuf *err)
 949 {
 950         assert(err);
 951
 952         if ((new_sha1 && !is_null_sha1(new_sha1)) ?
 953             check_refname_format(refname, REFNAME_ALLOW_ONELEVEL) :
 954             !refname_is_safe(refname)) {
 955                 strbuf_addf(err, "refusing to update ref with bad name '%s'",
 956                             refname);
 957                 return -1;
 958         }
 959
 960         flags |= (new_sha1 ? REF_HAVE_NEW : 0) | (old_sha1 ? REF_HAVE_OLD : 0);
 961
 962         ref_transaction_add_update(transaction, refname, flags,
 963                                    new_sha1, old_sha1, msg);
 964         return 0;
 965 }
 966
 967 int ref_transaction_create(struct ref_transaction *transaction,
 968                            const char *refname,
 969                            const unsigned char *new_sha1,
 970                            unsigned int flags, const char *msg,
 971                            struct strbuf *err)
 972 {
 973         if (!new_sha1 || is_null_sha1(new_sha1))
 974                 die("BUG: create called without valid new_sha1");
 975         return ref_transaction_update(transaction, refname, new_sha1,
 976                                       null_sha1, flags, msg, err);
 977 }
 978
 979 int ref_transaction_delete(struct ref_transaction *transaction,
 980                            const char *refname,
 981                            const unsigned char *old_sha1,
 982                            unsigned int flags, const char *msg,
 983                            struct strbuf *err)
 984 {
 985         if (old_sha1 && is_null_sha1(old_sha1))
 986                 die("BUG: delete called with old_sha1 set to zeros");
 987         return ref_transaction_update(transaction, refname,
 988                                       null_sha1, old_sha1,
 989                                       flags, msg, err);
 990 }
 991
 992 int ref_transaction_verify(struct ref_transaction *transaction,
 993                            const char *refname,
 994                            const unsigned char *old_sha1,
 995                            unsigned int flags,
 996                            struct strbuf *err)
 997 {
 998         if (!old_sha1)
 999                 die("BUG: verify called with old_sha1 set to NULL");
1000         return ref_transaction_update(transaction, refname,
1001                                       NULL, old_sha1,
1002                                       flags, NULL, err);
1003 }
1004
1005 int update_ref_oid(const char *msg, const char *refname,
1006                const struct object_id *new_oid, const struct object_id *old_oid,
1007                unsigned int flags, enum action_on_err onerr)
1008 {
1009         return update_ref(msg, refname, new_oid ? new_oid->hash : NULL,
1010                 old_oid ? old_oid->hash : NULL, flags, onerr);
1011 }
1012
1013 int refs_update_ref(struct ref_store *refs, const char *msg,
1014                     const char *refname, const unsigned char *new_sha1,
1015                     const unsigned char *old_sha1, unsigned int flags,
1016                     enum action_on_err onerr)
1017 {
1018         struct ref_transaction *t = NULL;
1019         struct strbuf err = STRBUF_INIT;
1020         int ret = 0;
1021
1022         if (ref_type(refname) == REF_TYPE_PSEUDOREF) {
1023                 assert(refs == get_main_ref_store());
1024                 ret = write_pseudoref(refname, new_sha1, old_sha1, &err);
1025         } else {
1026                 t = ref_store_transaction_begin(refs, &err);
1027                 if (!t ||
1028                     ref_transaction_update(t, refname, new_sha1, old_sha1,
1029                                            flags, msg, &err) ||
1030                     ref_transaction_commit(t, &err)) {
1031                         ret = 1;
1032                         ref_transaction_free(t);
1033                 }
1034         }
1035         if (ret) {
1036                 const char *str = "update_ref failed for ref '%s': %s";
1037
1038                 switch (onerr) {
1039                 case UPDATE_REFS_MSG_ON_ERR:
1040                         error(str, refname, err.buf);
1041                         break;
1042                 case UPDATE_REFS_DIE_ON_ERR:
1043                         die(str, refname, err.buf);
1044                         break;
1045                 case UPDATE_REFS_QUIET_ON_ERR:
1046                         break;
1047                 }
1048                 strbuf_release(&err);
1049                 return 1;
1050         }
1051         strbuf_release(&err);
1052         if (t)
1053                 ref_transaction_free(t);
1054         return 0;
1055 }
1056
1057 int update_ref(const char *msg, const char *refname,
1058                const unsigned char *new_sha1,
1059                const unsigned char *old_sha1,
1060                unsigned int flags, enum action_on_err onerr)
1061 {
1062         return refs_update_ref(get_main_ref_store(), msg, refname, new_sha1,
1063                                old_sha1, flags, onerr);
1064 }
1065
1066 char *shorten_unambiguous_ref(const char *refname, int strict)
1067 {
1068         int i;
1069         static char **scanf_fmts;
1070         static int nr_rules;
1071         char *short_name;
1072         struct strbuf resolved_buf = STRBUF_INIT;
1073
1074         if (!nr_rules) {
1075                 /*
1076                  * Pre-generate scanf formats from ref_rev_parse_rules[].
1077                  * Generate a format suitable for scanf from a
1078                  * ref_rev_parse_rules rule by interpolating "%s" at the
1079                  * location of the "%.*s".
1080                  */
1081                 size_t total_len = 0;
1082                 size_t offset = 0;
1083
1084                 /* the rule list is NULL terminated, count them first */
1085                 for (nr_rules = 0; ref_rev_parse_rules[nr_rules]; nr_rules++)
1086                         /* -2 for strlen("%.*s") - strlen("%s"); +1 for NUL */
1087                         total_len += strlen(ref_rev_parse_rules[nr_rules]) - 2 + 1;
1088
1089                 scanf_fmts = xmalloc(st_add(st_mult(sizeof(char *), nr_rules), total_len));
1090
1091                 offset = 0;
1092                 for (i = 0; i < nr_rules; i++) {
1093                         assert(offset < total_len);
1094                         scanf_fmts[i] = (char *)&scanf_fmts[nr_rules] + offset;
1095                         offset += snprintf(scanf_fmts[i], total_len - offset,
1096                                            ref_rev_parse_rules[i], 2, "%s") + 1;
1097                 }
1098         }
1099
1100         /* bail out if there are no rules */
1101         if (!nr_rules)
1102                 return xstrdup(refname);
1103
1104         /* buffer for scanf result, at most refname must fit */
1105         short_name = xstrdup(refname);
1106
1107         /* skip first rule, it will always match */
1108         for (i = nr_rules - 1; i > 0 ; --i) {
1109                 int j;
1110                 int rules_to_fail = i;
1111                 int short_name_len;
1112
1113                 if (1 != sscanf(refname, scanf_fmts[i], short_name))
1114                         continue;
1115
1116                 short_name_len = strlen(short_name);
1117
1118                 /*
1119                  * in strict mode, all (except the matched one) rules
1120                  * must fail to resolve to a valid non-ambiguous ref
1121                  */
1122                 if (strict)
1123                         rules_to_fail = nr_rules;
1124
1125                 /*
1126                  * check if the short name resolves to a valid ref,
1127                  * but use only rules prior to the matched one
1128                  */
1129                 for (j = 0; j < rules_to_fail; j++) {
1130                         const char *rule = ref_rev_parse_rules[j];
1131
1132                         /* skip matched rule */
1133                         if (i == j)
1134                                 continue;
1135
1136                         /*
1137                          * the short name is ambiguous, if it resolves
1138                          * (with this previous rule) to a valid ref
1139                          * read_ref() returns 0 on success
1140                          */
1141                         strbuf_reset(&resolved_buf);
1142                         strbuf_addf(&resolved_buf, rule,
1143                                     short_name_len, short_name);
1144                         if (ref_exists(resolved_buf.buf))
1145                                 break;
1146                 }
1147
1148                 /*
1149                  * short name is non-ambiguous if all previous rules
1150                  * haven't resolved to a valid ref
1151                  */
1152                 if (j == rules_to_fail) {
1153                         strbuf_release(&resolved_buf);
1154                         return short_name;
1155                 }
1156         }
1157
1158         strbuf_release(&resolved_buf);
1159         free(short_name);
1160         return xstrdup(refname);
1161 }
1162
1163 static struct string_list *hide_refs;
1164
1165 int parse_hide_refs_config(const char *var, const char *value, const char *section)
1166 {
1167         const char *key;
1168         if (!strcmp("transfer.hiderefs", var) ||
1169             (!parse_config_key(var, section, NULL, NULL, &key) &&
1170              !strcmp(key, "hiderefs"))) {
1171                 char *ref;
1172                 int len;
1173
1174                 if (!value)
1175                         return config_error_nonbool(var);
1176                 ref = xstrdup(value);
1177                 len = strlen(ref);
1178                 while (len && ref[len - 1] == '/')
1179                         ref[--len] = '\0';
1180                 if (!hide_refs) {
1181                         hide_refs = xcalloc(1, sizeof(*hide_refs));
1182                         hide_refs->strdup_strings = 1;
1183                 }
1184                 string_list_append(hide_refs, ref);
1185         }
1186         return 0;
1187 }
1188
1189 int ref_is_hidden(const char *refname, const char *refname_full)
1190 {
1191         int i;
1192
1193         if (!hide_refs)
1194                 return 0;
1195         for (i = hide_refs->nr - 1; i >= 0; i--) {
1196                 const char *match = hide_refs->items[i].string;
1197                 const char *subject;
1198                 int neg = 0;
1199                 const char *p;
1200
1201                 if (*match == '!') {
1202                         neg = 1;
1203                         match++;
1204                 }
1205
1206                 if (*match == '^') {
1207                         subject = refname_full;
1208                         match++;
1209                 } else {
1210                         subject = refname;
1211                 }
1212
1213                 /* refname can be NULL when namespaces are used. */
1214                 if (subject &&
1215                     skip_prefix(subject, match, &p) &&
1216                     (!*p || *p == '/'))
1217                         return !neg;
1218         }
1219         return 0;
1220 }
1221
1222 const char *find_descendant_ref(const char *dirname,
1223                                 const struct string_list *extras,
1224                                 const struct string_list *skip)
1225 {
1226         int pos;
1227
1228         if (!extras)
1229                 return NULL;
1230
1231         /*
1232          * Look at the place where dirname would be inserted into
1233          * extras. If there is an entry at that position that starts
1234          * with dirname (remember, dirname includes the trailing
1235          * slash) and is not in skip, then we have a conflict.
1236          */
1237         for (pos = string_list_find_insert_index(extras, dirname, 0);
1238              pos < extras->nr; pos++) {
1239                 const char *extra_refname = extras->items[pos].string;
1240
1241                 if (!starts_with(extra_refname, dirname))
1242                         break;
1243
1244                 if (!skip || !string_list_has_string(skip, extra_refname))
1245                         return extra_refname;
1246         }
1247         return NULL;
1248 }
1249
1250 int refs_rename_ref_available(struct ref_store *refs,
1251                               const char *old_refname,
1252                               const char *new_refname)
1253 {
1254         struct string_list skip = STRING_LIST_INIT_NODUP;
1255         struct strbuf err = STRBUF_INIT;
1256         int ok;
1257
1258         string_list_insert(&skip, old_refname);
1259         ok = !refs_verify_refname_available(refs, new_refname,
1260                                             NULL, &skip, &err);
1261         if (!ok)
1262                 error("%s", err.buf);
1263
1264         string_list_clear(&skip, 0);
1265         strbuf_release(&err);
1266         return ok;
1267 }
1268
1269 int head_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1270 {
1271         struct object_id oid;
1272         int flag;
1273
1274         if (submodule) {
1275                 if (resolve_gitlink_ref(submodule, "HEAD", oid.hash) == 0)
1276                         return fn("HEAD", &oid, 0, cb_data);
1277
1278                 return 0;
1279         }
1280
1281         if (!read_ref_full("HEAD", RESOLVE_REF_READING, oid.hash, &flag))
1282                 return fn("HEAD", &oid, flag, cb_data);
1283
1284         return 0;
1285 }
1286
1287 int head_ref(each_ref_fn fn, void *cb_data)
1288 {
1289         return head_ref_submodule(NULL, fn, cb_data);
1290 }
1291
1292 struct ref_iterator *refs_ref_iterator_begin(
1293                 struct ref_store *refs,
1294                 const char *prefix, int trim, int flags)
1295 {
1296         struct ref_iterator *iter;
1297
1298         if (ref_paranoia < 0)
1299                 ref_paranoia = git_env_bool("GIT_REF_PARANOIA", 0);
1300         if (ref_paranoia)
1301                 flags |= DO_FOR_EACH_INCLUDE_BROKEN;
1302
1303         iter = refs->be->iterator_begin(refs, prefix, flags);
1304
1305         /*
1306          * `iterator_begin()` already takes care of prefix, but we
1307          * might need to do some trimming:
1308          */
1309         if (trim)
1310                 iter = prefix_ref_iterator_begin(iter, "", trim);
1311
1312         return iter;
1313 }
1314
1315 /*
1316  * Call fn for each reference in the specified submodule for which the
1317  * refname begins with prefix. If trim is non-zero, then trim that
1318  * many characters off the beginning of each refname before passing
1319  * the refname to fn. flags can be DO_FOR_EACH_INCLUDE_BROKEN to
1320  * include broken references in the iteration. If fn ever returns a
1321  * non-zero value, stop the iteration and return that value;
1322  * otherwise, return 0.
1323  */
1324 static int do_for_each_ref(struct ref_store *refs, const char *prefix,
1325                            each_ref_fn fn, int trim, int flags, void *cb_data)
1326 {
1327         struct ref_iterator *iter;
1328
1329         if (!refs)
1330                 return 0;
1331
1332         iter = refs_ref_iterator_begin(refs, prefix, trim, flags);
1333
1334         return do_for_each_ref_iterator(iter, fn, cb_data);
1335 }
1336
1337 int refs_for_each_ref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1338 {
1339         return do_for_each_ref(refs, "", fn, 0, 0, cb_data);
1340 }
1341
1342 int for_each_ref(each_ref_fn fn, void *cb_data)
1343 {
1344         return refs_for_each_ref(get_main_ref_store(), fn, cb_data);
1345 }
1346
1347 int for_each_ref_submodule(const char *submodule, each_ref_fn fn, void *cb_data)
1348 {
1349         return refs_for_each_ref(get_submodule_ref_store(submodule), fn, cb_data);
1350 }
1351
1352 int refs_for_each_ref_in(struct ref_store *refs, const char *prefix,
1353                          each_ref_fn fn, void *cb_data)
1354 {
1355         return do_for_each_ref(refs, prefix, fn, strlen(prefix), 0, cb_data);
1356 }
1357
1358 int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data)
1359 {
1360         return refs_for_each_ref_in(get_main_ref_store(), prefix, fn, cb_data);
1361 }
1362
1363 int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data, unsigned int broken)
1364 {
1365         unsigned int flag = 0;
1366
1367         if (broken)
1368                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1369         return do_for_each_ref(get_main_ref_store(),
1370                                prefix, fn, 0, flag, cb_data);
1371 }
1372
1373 int for_each_ref_in_submodule(const char *submodule, const char *prefix,
1374                               each_ref_fn fn, void *cb_data)
1375 {
1376         return refs_for_each_ref_in(get_submodule_ref_store(submodule),
1377                                     prefix, fn, cb_data);
1378 }
1379
1380 int for_each_fullref_in_submodule(const char *submodule, const char *prefix,
1381                                   each_ref_fn fn, void *cb_data,
1382                                   unsigned int broken)
1383 {
1384         unsigned int flag = 0;
1385
1386         if (broken)
1387                 flag = DO_FOR_EACH_INCLUDE_BROKEN;
1388         return do_for_each_ref(get_submodule_ref_store(submodule),
1389                                prefix, fn, 0, flag, cb_data);
1390 }
1391
1392 int for_each_replace_ref(each_ref_fn fn, void *cb_data)
1393 {
1394         return do_for_each_ref(get_main_ref_store(),
1395                                git_replace_ref_base, fn,
1396                                strlen(git_replace_ref_base),
1397                                0, cb_data);
1398 }
1399
1400 int for_each_namespaced_ref(each_ref_fn fn, void *cb_data)
1401 {
1402         struct strbuf buf = STRBUF_INIT;
1403         int ret;
1404         strbuf_addf(&buf, "%srefs/", get_git_namespace());
1405         ret = do_for_each_ref(get_main_ref_store(),
1406                               buf.buf, fn, 0, 0, cb_data);
1407         strbuf_release(&buf);
1408         return ret;
1409 }
1410
1411 int refs_for_each_rawref(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1412 {
1413         return do_for_each_ref(refs, "", fn, 0,
1414                                DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
1415 }
1416
1417 int for_each_rawref(each_ref_fn fn, void *cb_data)
1418 {
1419         return refs_for_each_rawref(get_main_ref_store(), fn, cb_data);
1420 }
1421
1422 int refs_read_raw_ref(struct ref_store *ref_store,
1423                       const char *refname, unsigned char *sha1,
1424                       struct strbuf *referent, unsigned int *type)
1425 {
1426         return ref_store->be->read_raw_ref(ref_store, refname, sha1, referent, type);
1427 }
1428
1429 /* This function needs to return a meaningful errno on failure */
1430 const char *refs_resolve_ref_unsafe(struct ref_store *refs,
1431                                     const char *refname,
1432                                     int resolve_flags,
1433                                     unsigned char *sha1, int *flags)
1434 {
1435         static struct strbuf sb_refname = STRBUF_INIT;
1436         int unused_flags;
1437         int symref_count;
1438
1439         if (!flags)
1440                 flags = &unused_flags;
1441
1442         *flags = 0;
1443
1444         if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1445                 if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1446                     !refname_is_safe(refname)) {
1447                         errno = EINVAL;
1448                         return NULL;
1449                 }
1450
1451                 /*
1452                  * dwim_ref() uses REF_ISBROKEN to distinguish between
1453                  * missing refs and refs that were present but invalid,
1454                  * to complain about the latter to stderr.
1455                  *
1456                  * We don't know whether the ref exists, so don't set
1457                  * REF_ISBROKEN yet.
1458                  */
1459                 *flags |= REF_BAD_NAME;
1460         }
1461
1462         for (symref_count = 0; symref_count < SYMREF_MAXDEPTH; symref_count++) {
1463                 unsigned int read_flags = 0;
1464
1465                 if (refs_read_raw_ref(refs, refname,
1466                                       sha1, &sb_refname, &read_flags)) {
1467                         *flags |= read_flags;
1468                         if (errno != ENOENT || (resolve_flags & RESOLVE_REF_READING))
1469                                 return NULL;
1470                         hashclr(sha1);
1471                         if (*flags & REF_BAD_NAME)
1472                                 *flags |= REF_ISBROKEN;
1473                         return refname;
1474                 }
1475
1476                 *flags |= read_flags;
1477
1478                 if (!(read_flags & REF_ISSYMREF)) {
1479                         if (*flags & REF_BAD_NAME) {
1480                                 hashclr(sha1);
1481                                 *flags |= REF_ISBROKEN;
1482                         }
1483                         return refname;
1484                 }
1485
1486                 refname = sb_refname.buf;
1487                 if (resolve_flags & RESOLVE_REF_NO_RECURSE) {
1488                         hashclr(sha1);
1489                         return refname;
1490                 }
1491                 if (check_refname_format(refname, REFNAME_ALLOW_ONELEVEL)) {
1492                         if (!(resolve_flags & RESOLVE_REF_ALLOW_BAD_NAME) ||
1493                             !refname_is_safe(refname)) {
1494                                 errno = EINVAL;
1495                                 return NULL;
1496                         }
1497
1498                         *flags |= REF_ISBROKEN | REF_BAD_NAME;
1499                 }
1500         }
1501
1502         errno = ELOOP;
1503         return NULL;
1504 }
1505
1506 /* backend functions */
1507 int refs_init_db(struct strbuf *err)
1508 {
1509         struct ref_store *refs = get_main_ref_store();
1510
1511         return refs->be->init_db(refs, err);
1512 }
1513
1514 const char *resolve_ref_unsafe(const char *refname, int resolve_flags,
1515                                unsigned char *sha1, int *flags)
1516 {
1517         return refs_resolve_ref_unsafe(get_main_ref_store(), refname,
1518                                        resolve_flags, sha1, flags);
1519 }
1520
1521 int resolve_gitlink_ref(const char *submodule, const char *refname,
1522                         unsigned char *sha1)
1523 {
1524         size_t len = strlen(submodule);
1525         struct ref_store *refs;
1526         int flags;
1527
1528         while (len && submodule[len - 1] == '/')
1529                 len--;
1530
1531         if (!len)
1532                 return -1;
1533
1534         if (submodule[len]) {
1535                 /* We need to strip off one or more trailing slashes */
1536                 char *stripped = xmemdupz(submodule, len);
1537
1538                 refs = get_submodule_ref_store(stripped);
1539                 free(stripped);
1540         } else {
1541                 refs = get_submodule_ref_store(submodule);
1542         }
1543
1544         if (!refs)
1545                 return -1;
1546
1547         if (!refs_resolve_ref_unsafe(refs, refname, 0, sha1, &flags) ||
1548             is_null_sha1(sha1))
1549                 return -1;
1550         return 0;
1551 }
1552
1553 struct ref_store_hash_entry
1554 {
1555         struct hashmap_entry ent; /* must be the first member! */
1556
1557         struct ref_store *refs;
1558
1559         /* NUL-terminated identifier of the ref store: */
1560         char name[FLEX_ARRAY];
1561 };
1562
1563 static int ref_store_hash_cmp(const void *unused_cmp_data,
1564                               const void *entry, const void *entry_or_key,
1565                               const void *keydata)
1566 {
1567         const struct ref_store_hash_entry *e1 = entry, *e2 = entry_or_key;
1568         const char *name = keydata ? keydata : e2->name;
1569
1570         return strcmp(e1->name, name);
1571 }
1572
1573 static struct ref_store_hash_entry *alloc_ref_store_hash_entry(
1574                 const char *name, struct ref_store *refs)
1575 {
1576         struct ref_store_hash_entry *entry;
1577
1578         FLEX_ALLOC_STR(entry, name, name);
1579         hashmap_entry_init(entry, strhash(name));
1580         entry->refs = refs;
1581         return entry;
1582 }
1583
1584 /* A pointer to the ref_store for the main repository: */
1585 static struct ref_store *main_ref_store;
1586
1587 /* A hashmap of ref_stores, stored by submodule name: */
1588 static struct hashmap submodule_ref_stores;
1589
1590 /* A hashmap of ref_stores, stored by worktree id: */
1591 static struct hashmap worktree_ref_stores;
1592
1593 /*
1594  * Look up a ref store by name. If that ref_store hasn't been
1595  * registered yet, return NULL.
1596  */
1597 static struct ref_store *lookup_ref_store_map(struct hashmap *map,
1598                                               const char *name)
1599 {
1600         struct ref_store_hash_entry *entry;
1601
1602         if (!map->tablesize)
1603                 /* It's initialized on demand in register_ref_store(). */
1604                 return NULL;
1605
1606         entry = hashmap_get_from_hash(map, strhash(name), name);
1607         return entry ? entry->refs : NULL;
1608 }
1609
1610 /*
1611  * Create, record, and return a ref_store instance for the specified
1612  * gitdir.
1613  */
1614 static struct ref_store *ref_store_init(const char *gitdir,
1615                                         unsigned int flags)
1616 {
1617         const char *be_name = "files";
1618         struct ref_storage_be *be = find_ref_storage_backend(be_name);
1619         struct ref_store *refs;
1620
1621         if (!be)
1622                 die("BUG: reference backend %s is unknown", be_name);
1623
1624         refs = be->init(gitdir, flags);
1625         return refs;
1626 }
1627
1628 struct ref_store *get_main_ref_store(void)
1629 {
1630         if (main_ref_store)
1631                 return main_ref_store;
1632
1633         main_ref_store = ref_store_init(get_git_dir(), REF_STORE_ALL_CAPS);
1634         return main_ref_store;
1635 }
1636
1637 /*
1638  * Associate a ref store with a name. It is a fatal error to call this
1639  * function twice for the same name.
1640  */
1641 static void register_ref_store_map(struct hashmap *map,
1642                                    const char *type,
1643                                    struct ref_store *refs,
1644                                    const char *name)
1645 {
1646         if (!map->tablesize)
1647                 hashmap_init(map, ref_store_hash_cmp, NULL, 0);
1648
1649         if (hashmap_put(map, alloc_ref_store_hash_entry(name, refs)))
1650                 die("BUG: %s ref_store '%s' initialized twice", type, name);
1651 }
1652
1653 struct ref_store *get_submodule_ref_store(const char *submodule)
1654 {
1655         struct strbuf submodule_sb = STRBUF_INIT;
1656         struct ref_store *refs;
1657         int ret;
1658
1659         if (!submodule || !*submodule) {
1660                 /*
1661                  * FIXME: This case is ideally not allowed. But that
1662                  * can't happen until we clean up all the callers.
1663                  */
1664                 return get_main_ref_store();
1665         }
1666
1667         refs = lookup_ref_store_map(&submodule_ref_stores, submodule);
1668         if (refs)
1669                 return refs;
1670
1671         strbuf_addstr(&submodule_sb, submodule);
1672         ret = is_nonbare_repository_dir(&submodule_sb);
1673         strbuf_release(&submodule_sb);
1674         if (!ret)
1675                 return NULL;
1676
1677         ret = submodule_to_gitdir(&submodule_sb, submodule);
1678         if (ret) {
1679                 strbuf_release(&submodule_sb);
1680                 return NULL;
1681         }
1682
1683         /* assume that add_submodule_odb() has been called */
1684         refs = ref_store_init(submodule_sb.buf,
1685                               REF_STORE_READ | REF_STORE_ODB);
1686         register_ref_store_map(&submodule_ref_stores, "submodule",
1687                                refs, submodule);
1688
1689         strbuf_release(&submodule_sb);
1690         return refs;
1691 }
1692
1693 struct ref_store *get_worktree_ref_store(const struct worktree *wt)
1694 {
1695         struct ref_store *refs;
1696         const char *id;
1697
1698         if (wt->is_current)
1699                 return get_main_ref_store();
1700
1701         id = wt->id ? wt->id : "/";
1702         refs = lookup_ref_store_map(&worktree_ref_stores, id);
1703         if (refs)
1704                 return refs;
1705
1706         if (wt->id)
1707                 refs = ref_store_init(git_common_path("worktrees/%s", wt->id),
1708                                       REF_STORE_ALL_CAPS);
1709         else
1710                 refs = ref_store_init(get_git_common_dir(),
1711                                       REF_STORE_ALL_CAPS);
1712
1713         if (refs)
1714                 register_ref_store_map(&worktree_ref_stores, "worktree",
1715                                        refs, id);
1716         return refs;
1717 }
1718
1719 void base_ref_store_init(struct ref_store *refs,
1720                          const struct ref_storage_be *be)
1721 {
1722         refs->be = be;
1723 }
1724
1725 /* backend functions */
1726 int refs_pack_refs(struct ref_store *refs, unsigned int flags)
1727 {
1728         return refs->be->pack_refs(refs, flags);
1729 }
1730
1731 int refs_peel_ref(struct ref_store *refs, const char *refname,
1732                   unsigned char *sha1)
1733 {
1734         return refs->be->peel_ref(refs, refname, sha1);
1735 }
1736
1737 int peel_ref(const char *refname, unsigned char *sha1)
1738 {
1739         return refs_peel_ref(get_main_ref_store(), refname, sha1);
1740 }
1741
1742 int refs_create_symref(struct ref_store *refs,
1743                        const char *ref_target,
1744                        const char *refs_heads_master,
1745                        const char *logmsg)
1746 {
1747         return refs->be->create_symref(refs, ref_target,
1748                                        refs_heads_master,
1749                                        logmsg);
1750 }
1751
1752 int create_symref(const char *ref_target, const char *refs_heads_master,
1753                   const char *logmsg)
1754 {
1755         return refs_create_symref(get_main_ref_store(), ref_target,
1756                                   refs_heads_master, logmsg);
1757 }
1758
1759 int ref_update_reject_duplicates(struct string_list *refnames,
1760                                  struct strbuf *err)
1761 {
1762         size_t i, n = refnames->nr;
1763
1764         assert(err);
1765
1766         for (i = 1; i < n; i++) {
1767                 int cmp = strcmp(refnames->items[i - 1].string,
1768                                  refnames->items[i].string);
1769
1770                 if (!cmp) {
1771                         strbuf_addf(err,
1772                                     "multiple updates for ref '%s' not allowed.",
1773                                     refnames->items[i].string);
1774                         return 1;
1775                 } else if (cmp > 0) {
1776                         die("BUG: ref_update_reject_duplicates() received unsorted list");
1777                 }
1778         }
1779         return 0;
1780 }
1781
1782 int ref_transaction_prepare(struct ref_transaction *transaction,
1783                             struct strbuf *err)
1784 {
1785         struct ref_store *refs = transaction->ref_store;
1786
1787         switch (transaction->state) {
1788         case REF_TRANSACTION_OPEN:
1789                 /* Good. */
1790                 break;
1791         case REF_TRANSACTION_PREPARED:
1792                 die("BUG: prepare called twice on reference transaction");
1793                 break;
1794         case REF_TRANSACTION_CLOSED:
1795                 die("BUG: prepare called on a closed reference transaction");
1796                 break;
1797         default:
1798                 die("BUG: unexpected reference transaction state");
1799                 break;
1800         }
1801
1802         if (getenv(GIT_QUARANTINE_ENVIRONMENT)) {
1803                 strbuf_addstr(err,
1804                               _("ref updates forbidden inside quarantine environment"));
1805                 return -1;
1806         }
1807
1808         return refs->be->transaction_prepare(refs, transaction, err);
1809 }
1810
1811 int ref_transaction_abort(struct ref_transaction *transaction,
1812                           struct strbuf *err)
1813 {
1814         struct ref_store *refs = transaction->ref_store;
1815         int ret = 0;
1816
1817         switch (transaction->state) {
1818         case REF_TRANSACTION_OPEN:
1819                 /* No need to abort explicitly. */
1820                 break;
1821         case REF_TRANSACTION_PREPARED:
1822                 ret = refs->be->transaction_abort(refs, transaction, err);
1823                 break;
1824         case REF_TRANSACTION_CLOSED:
1825                 die("BUG: abort called on a closed reference transaction");
1826                 break;
1827         default:
1828                 die("BUG: unexpected reference transaction state");
1829                 break;
1830         }
1831
1832         ref_transaction_free(transaction);
1833         return ret;
1834 }
1835
1836 int ref_transaction_commit(struct ref_transaction *transaction,
1837                            struct strbuf *err)
1838 {
1839         struct ref_store *refs = transaction->ref_store;
1840         int ret;
1841
1842         switch (transaction->state) {
1843         case REF_TRANSACTION_OPEN:
1844                 /* Need to prepare first. */
1845                 ret = ref_transaction_prepare(transaction, err);
1846                 if (ret)
1847                         return ret;
1848                 break;
1849         case REF_TRANSACTION_PREPARED:
1850                 /* Fall through to finish. */
1851                 break;
1852         case REF_TRANSACTION_CLOSED:
1853                 die("BUG: commit called on a closed reference transaction");
1854                 break;
1855         default:
1856                 die("BUG: unexpected reference transaction state");
1857                 break;
1858         }
1859
1860         return refs->be->transaction_finish(refs, transaction, err);
1861 }
1862
1863 int refs_verify_refname_available(struct ref_store *refs,
1864                                   const char *refname,
1865                                   const struct string_list *extras,
1866                                   const struct string_list *skip,
1867                                   struct strbuf *err)
1868 {
1869         const char *slash;
1870         const char *extra_refname;
1871         struct strbuf dirname = STRBUF_INIT;
1872         struct strbuf referent = STRBUF_INIT;
1873         struct object_id oid;
1874         unsigned int type;
1875         struct ref_iterator *iter;
1876         int ok;
1877         int ret = -1;
1878
1879         /*
1880          * For the sake of comments in this function, suppose that
1881          * refname is "refs/foo/bar".
1882          */
1883
1884         assert(err);
1885
1886         strbuf_grow(&dirname, strlen(refname) + 1);
1887         for (slash = strchr(refname, '/'); slash; slash = strchr(slash + 1, '/')) {
1888                 /* Expand dirname to the new prefix, not including the trailing slash: */
1889                 strbuf_add(&dirname, refname + dirname.len, slash - refname - dirname.len);
1890
1891                 /*
1892                  * We are still at a leading dir of the refname (e.g.,
1893                  * "refs/foo"; if there is a reference with that name,
1894                  * it is a conflict, *unless* it is in skip.
1895                  */
1896                 if (skip && string_list_has_string(skip, dirname.buf))
1897                         continue;
1898
1899                 if (!refs_read_raw_ref(refs, dirname.buf, oid.hash, &referent, &type)) {
1900                         strbuf_addf(err, "'%s' exists; cannot create '%s'",
1901                                     dirname.buf, refname);
1902                         goto cleanup;
1903                 }
1904
1905                 if (extras && string_list_has_string(extras, dirname.buf)) {
1906                         strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1907                                     refname, dirname.buf);
1908                         goto cleanup;
1909                 }
1910         }
1911
1912         /*
1913          * We are at the leaf of our refname (e.g., "refs/foo/bar").
1914          * There is no point in searching for a reference with that
1915          * name, because a refname isn't considered to conflict with
1916          * itself. But we still need to check for references whose
1917          * names are in the "refs/foo/bar/" namespace, because they
1918          * *do* conflict.
1919          */
1920         strbuf_addstr(&dirname, refname + dirname.len);
1921         strbuf_addch(&dirname, '/');
1922
1923         iter = refs_ref_iterator_begin(refs, dirname.buf, 0,
1924                                        DO_FOR_EACH_INCLUDE_BROKEN);
1925         while ((ok = ref_iterator_advance(iter)) == ITER_OK) {
1926                 if (skip &&
1927                     string_list_has_string(skip, iter->refname))
1928                         continue;
1929
1930                 strbuf_addf(err, "'%s' exists; cannot create '%s'",
1931                             iter->refname, refname);
1932                 ref_iterator_abort(iter);
1933                 goto cleanup;
1934         }
1935
1936         if (ok != ITER_DONE)
1937                 die("BUG: error while iterating over references");
1938
1939         extra_refname = find_descendant_ref(dirname.buf, extras, skip);
1940         if (extra_refname)
1941                 strbuf_addf(err, "cannot process '%s' and '%s' at the same time",
1942                             refname, extra_refname);
1943         else
1944                 ret = 0;
1945
1946 cleanup:
1947         strbuf_release(&referent);
1948         strbuf_release(&dirname);
1949         return ret;
1950 }
1951
1952 int refs_for_each_reflog(struct ref_store *refs, each_ref_fn fn, void *cb_data)
1953 {
1954         struct ref_iterator *iter;
1955
1956         iter = refs->be->reflog_iterator_begin(refs);
1957
1958         return do_for_each_ref_iterator(iter, fn, cb_data);
1959 }
1960
1961 int for_each_reflog(each_ref_fn fn, void *cb_data)
1962 {
1963         return refs_for_each_reflog(get_main_ref_store(), fn, cb_data);
1964 }
1965
1966 int refs_for_each_reflog_ent_reverse(struct ref_store *refs,
1967                                      const char *refname,
1968                                      each_reflog_ent_fn fn,
1969                                      void *cb_data)
1970 {
1971         return refs->be->for_each_reflog_ent_reverse(refs, refname,
1972                                                      fn, cb_data);
1973 }
1974
1975 int for_each_reflog_ent_reverse(const char *refname, each_reflog_ent_fn fn,
1976                                 void *cb_data)
1977 {
1978         return refs_for_each_reflog_ent_reverse(get_main_ref_store(),
1979                                                 refname, fn, cb_data);
1980 }
1981
1982 int refs_for_each_reflog_ent(struct ref_store *refs, const char *refname,
1983                              each_reflog_ent_fn fn, void *cb_data)
1984 {
1985         return refs->be->for_each_reflog_ent(refs, refname, fn, cb_data);
1986 }
1987
1988 int for_each_reflog_ent(const char *refname, each_reflog_ent_fn fn,
1989                         void *cb_data)
1990 {
1991         return refs_for_each_reflog_ent(get_main_ref_store(), refname,
1992                                         fn, cb_data);
1993 }
1994
1995 int refs_reflog_exists(struct ref_store *refs, const char *refname)
1996 {
1997         return refs->be->reflog_exists(refs, refname);
1998 }
1999
2000 int reflog_exists(const char *refname)
2001 {
2002         return refs_reflog_exists(get_main_ref_store(), refname);
2003 }
2004
2005 int refs_create_reflog(struct ref_store *refs, const char *refname,
2006                        int force_create, struct strbuf *err)
2007 {
2008         return refs->be->create_reflog(refs, refname, force_create, err);
2009 }
2010
2011 int safe_create_reflog(const char *refname, int force_create,
2012                        struct strbuf *err)
2013 {
2014         return refs_create_reflog(get_main_ref_store(), refname,
2015                                   force_create, err);
2016 }
2017
2018 int refs_delete_reflog(struct ref_store *refs, const char *refname)
2019 {
2020         return refs->be->delete_reflog(refs, refname);
2021 }
2022
2023 int delete_reflog(const char *refname)
2024 {
2025         return refs_delete_reflog(get_main_ref_store(), refname);
2026 }
2027
2028 int refs_reflog_expire(struct ref_store *refs,
2029                        const char *refname, const unsigned char *sha1,
2030                        unsigned int flags,
2031                        reflog_expiry_prepare_fn prepare_fn,
2032                        reflog_expiry_should_prune_fn should_prune_fn,
2033                        reflog_expiry_cleanup_fn cleanup_fn,
2034                        void *policy_cb_data)
2035 {
2036         return refs->be->reflog_expire(refs, refname, sha1, flags,
2037                                        prepare_fn, should_prune_fn,
2038                                        cleanup_fn, policy_cb_data);
2039 }
2040
2041 int reflog_expire(const char *refname, const unsigned char *sha1,
2042                   unsigned int flags,
2043                   reflog_expiry_prepare_fn prepare_fn,
2044                   reflog_expiry_should_prune_fn should_prune_fn,
2045                   reflog_expiry_cleanup_fn cleanup_fn,
2046                   void *policy_cb_data)
2047 {
2048         return refs_reflog_expire(get_main_ref_store(),
2049                                   refname, sha1, flags,
2050                                   prepare_fn, should_prune_fn,
2051                                   cleanup_fn, policy_cb_data);
2052 }
2053
2054 int initial_ref_transaction_commit(struct ref_transaction *transaction,
2055                                    struct strbuf *err)
2056 {
2057         struct ref_store *refs = transaction->ref_store;
2058
2059         return refs->be->initial_transaction_commit(refs, transaction, err);
2060 }
2061
2062 int refs_delete_refs(struct ref_store *refs, const char *msg,
2063                      struct string_list *refnames, unsigned int flags)
2064 {
2065         return refs->be->delete_refs(refs, msg, refnames, flags);
2066 }
2067
2068 int delete_refs(const char *msg, struct string_list *refnames,
2069                 unsigned int flags)
2070 {
2071         return refs_delete_refs(get_main_ref_store(), msg, refnames, flags);
2072 }
2073
2074 int refs_rename_ref(struct ref_store *refs, const char *oldref,
2075                     const char *newref, const char *logmsg)
2076 {
2077         return refs->be->rename_ref(refs, oldref, newref, logmsg);
2078 }
2079
2080 int rename_ref(const char *oldref, const char *newref, const char *logmsg)
2081 {
2082         return refs_rename_ref(get_main_ref_store(), oldref, newref, logmsg);
2083 }