lib/reference.c

   1 /*
   2  * Copyright (c) 2018, 2019 Stefan Sperling <stsp@openbsd.org>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #include "got_compat.h"
  18
  19 #include <sys/types.h>
  20 #include <sys/queue.h>
  21 #include <sys/stat.h>
  22
  23 #include <errno.h>
  24 #include <dirent.h>
  25 #include <limits.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <unistd.h>
  30 #include <zlib.h>
  31 #include <time.h>
  32 #include <libgen.h>
  33
  34 #include "got_error.h"
  35 #include "got_object.h"
  36 #include "got_repository.h"
  37 #include "got_reference.h"
  38 #include "got_opentemp.h"
  39 #include "got_path.h"
  40
  41 #include "got_lib_hash.h"
  42 #include "got_lib_delta.h"
  43 #include "got_lib_inflate.h"
  44 #include "got_lib_object.h"
  45 #include "got_lib_object_idset.h"
  46 #include "got_lib_lockfile.h"
  47
  48 #ifndef nitems
  49 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
  50 #endif
  51
  52 #define GOT_REF_HEADS   "heads"
  53 #define GOT_REF_TAGS    "tags"
  54 #define GOT_REF_REMOTES "remotes"
  55
  56 /*
  57  * We do not resolve tags yet, and don't yet care about sorting refs either,
  58  * so packed-refs files we write contain a minimal header which disables all
  59  * packed-refs "traits" supported by Git.
  60  */
  61 #define GOT_PACKED_REFS_HEADER  "# pack-refs with:"
  62
  63 /* A symbolic reference. */
  64 struct got_symref {
  65         char *name;
  66         char *ref;
  67 };
  68
  69 #define GOT_REF_RECURSE_MAX     20
  70
  71 /* A non-symbolic reference (there is no better designation). */
  72 struct got_ref {
  73         char *name;
  74         struct got_object_id id;
  75 };
  76
  77 /* A reference which points to an arbitrary object. */
  78 struct got_reference {
  79         unsigned int flags;
  80 #define GOT_REF_IS_SYMBOLIC     0x01
  81 #define GOT_REF_IS_PACKED       0x02
  82
  83         union {
  84                 struct got_ref ref;
  85                 struct got_symref symref;
  86         } ref;
  87
  88         struct got_lockfile *lf;
  89         time_t mtime;
  90
  91         /* Cached timestamp for got_ref_cmp_by_commit_timestamp_descending() */
  92         time_t committer_time;
  93 };
  94
  95 static const struct got_error *
  96 alloc_ref(struct got_reference **ref, const char *name,
  97     struct got_object_id *id, int flags, time_t mtime)
  98 {
  99         const struct got_error *err = NULL;
 100
 101         *ref = calloc(1, sizeof(**ref));
 102         if (*ref == NULL)
 103                 return got_error_from_errno("calloc");
 104
 105         memcpy(&(*ref)->ref.ref.id, id, sizeof((*ref)->ref.ref.id));
 106         (*ref)->flags = flags;
 107         (*ref)->ref.ref.name = strdup(name);
 108         (*ref)->mtime = mtime;
 109         if ((*ref)->ref.ref.name == NULL) {
 110                 err = got_error_from_errno("strdup");
 111                 got_ref_close(*ref);
 112                 *ref = NULL;
 113         }
 114         return err;
 115 }
 116
 117 static const struct got_error *
 118 alloc_symref(struct got_reference **ref, const char *name,
 119     const char *target_ref, int flags)
 120 {
 121         const struct got_error *err = NULL;
 122
 123         *ref = calloc(1, sizeof(**ref));
 124         if (*ref == NULL)
 125                 return got_error_from_errno("calloc");
 126
 127         (*ref)->flags = GOT_REF_IS_SYMBOLIC | flags;
 128         (*ref)->ref.symref.name = strdup(name);
 129         if ((*ref)->ref.symref.name == NULL) {
 130                 err = got_error_from_errno("strdup");
 131                 got_ref_close(*ref);
 132                 *ref = NULL;
 133                 return err;
 134         }
 135         (*ref)->ref.symref.ref = strdup(target_ref);
 136         if ((*ref)->ref.symref.ref == NULL) {
 137                 err = got_error_from_errno("strdup");
 138                 got_ref_close(*ref);
 139                 *ref = NULL;
 140         }
 141         return err;
 142 }
 143
 144 static const struct got_error *
 145 parse_symref(struct got_reference **ref, const char *name, const char *line)
 146 {
 147         if (line[0] == '\0')
 148                 return got_error(GOT_ERR_BAD_REF_DATA);
 149
 150         return alloc_symref(ref, name, line, 0);
 151 }
 152
 153 static const struct got_error *
 154 parse_ref_line(struct got_reference **ref, const char *name, const char *line,
 155     time_t mtime, enum got_hash_algorithm algo)
 156 {
 157         struct got_object_id id;
 158
 159         if (strncmp(line, "ref: ", 5) == 0) {
 160                 line += 5;
 161                 return parse_symref(ref, name, line);
 162         }
 163
 164         if (!got_parse_object_id(&id, line, algo))
 165                 return got_error(GOT_ERR_BAD_REF_DATA);
 166
 167         return alloc_ref(ref, name, &id, 0, mtime);
 168 }
 169
 170 static const struct got_error *
 171 parse_ref_file(struct got_reference **ref, const char *name,
 172     const char *absname, const char *abspath, int lock,
 173     enum got_hash_algorithm algo)
 174 {
 175         const struct got_error *err = NULL;
 176         FILE *f;
 177         char *line = NULL;
 178         size_t linesize = 0;
 179         ssize_t linelen;
 180         struct got_lockfile *lf = NULL;
 181         struct stat sb;
 182
 183         if (lock) {
 184                 err = got_lockfile_lock(&lf, abspath, -1);
 185                 if (err) {
 186                         if (err->code == GOT_ERR_ERRNO && errno == ENOENT)
 187                                 err = got_error_not_ref(name);
 188                         return err;
 189                 }
 190         }
 191
 192         f = fopen(abspath, "rbe");
 193         if (f == NULL) {
 194                 if (errno != ENOTDIR && errno != ENOENT)
 195                         err = got_error_from_errno2("fopen", abspath);
 196                 else
 197                         err = got_error_not_ref(name);
 198                 if (lock)
 199                         got_lockfile_unlock(lf, -1);
 200                 return err;
 201         }
 202         if (fstat(fileno(f), &sb) == -1) {
 203                 err = got_error_from_errno2("fstat", abspath);
 204                 goto done;
 205         }
 206
 207         linelen = getline(&line, &linesize, f);
 208         if (linelen == -1) {
 209                 if (feof(f))
 210                         err = NULL; /* ignore empty files (could be locks) */
 211                 else {
 212                         if (errno == EISDIR)
 213                                 err = got_error(GOT_ERR_NOT_REF);
 214                         else if (ferror(f))
 215                                 err = got_ferror(f, GOT_ERR_IO);
 216                         else
 217                                 err = got_error_from_errno2("getline", abspath);
 218                 }
 219                 if (lock)
 220                         got_lockfile_unlock(lf, -1);
 221                 goto done;
 222         }
 223         while (linelen > 0 && line[linelen - 1] == '\n') {
 224                 line[linelen - 1] = '\0';
 225                 linelen--;
 226         }
 227
 228         err = parse_ref_line(ref, absname, line, sb.st_mtime, algo);
 229         if (lock) {
 230                 if (err)
 231                         got_lockfile_unlock(lf, -1);
 232                 else {
 233                         if (*ref)
 234                                 (*ref)->lf = lf;
 235                         else
 236                                 got_lockfile_unlock(lf, -1);
 237                 }
 238         }
 239 done:
 240         free(line);
 241         if (fclose(f) == EOF && err == NULL) {
 242                 err = got_error_from_errno("fclose");
 243                 if (*ref) {
 244                         if (lock)
 245                                 got_ref_unlock(*ref);
 246                         got_ref_close(*ref);
 247                         *ref = NULL;
 248                 }
 249         }
 250         return err;
 251 }
 252
 253 static int
 254 is_well_known_ref(const char *refname)
 255 {
 256         return (strcmp(refname, GOT_REF_HEAD) == 0 ||
 257             strcmp(refname, GOT_REF_ORIG_HEAD) == 0 ||
 258             strcmp(refname, GOT_REF_MERGE_HEAD) == 0 ||
 259             strcmp(refname, GOT_REF_FETCH_HEAD) == 0);
 260 }
 261
 262 static char *
 263 get_refs_dir_path(struct got_repository *repo, const char *refname)
 264 {
 265         if (is_well_known_ref(refname) || strncmp(refname, "refs/", 5) == 0)
 266                 return strdup(got_repo_get_path_git_dir(repo));
 267
 268         return got_repo_get_path_refs(repo);
 269 }
 270
 271 const struct got_error *
 272 got_ref_alloc(struct got_reference **ref, const char *name,
 273     struct got_object_id *id)
 274 {
 275         if (!got_ref_name_is_valid(name))
 276                 return got_error_path(name, GOT_ERR_BAD_REF_NAME);
 277
 278         return alloc_ref(ref, name, id, 0, 0);
 279 }
 280
 281 const struct got_error *
 282 got_ref_alloc_symref(struct got_reference **ref, const char *name,
 283         struct got_reference *target_ref)
 284 {
 285         if (!got_ref_name_is_valid(name))
 286                 return got_error_path(name, GOT_ERR_BAD_REF_NAME);
 287
 288         return alloc_symref(ref, name, got_ref_get_name(target_ref), 0);
 289 }
 290
 291 static const struct got_error *
 292 parse_packed_ref_line(struct got_reference **ref, const char *abs_refname,
 293     const char *line, time_t mtime, enum got_hash_algorithm algo)
 294 {
 295         struct got_object_id id;
 296         const char *name;
 297
 298         *ref = NULL;
 299
 300         if (line[0] == '#' || line[0] == '^')
 301                 return NULL;
 302
 303         if (!got_parse_object_id(&id, line, algo))
 304                 return got_error(GOT_ERR_BAD_REF_DATA);
 305
 306         if (abs_refname) {
 307                 if (strcmp(line + SHA1_DIGEST_STRING_LENGTH, abs_refname) != 0)
 308                         return NULL;
 309                 name = abs_refname;
 310         } else
 311                 name = line + SHA1_DIGEST_STRING_LENGTH;
 312
 313         return alloc_ref(ref, name, &id, GOT_REF_IS_PACKED, mtime);
 314 }
 315
 316 static const struct got_error *
 317 open_packed_ref(struct got_reference **ref, FILE *f, const char **subdirs,
 318     int nsubdirs, const char *refname, time_t mtime,
 319     enum got_hash_algorithm algo)
 320 {
 321         const struct got_error *err = NULL;
 322         char *abs_refname;
 323         char *line = NULL;
 324         size_t linesize = 0;
 325         ssize_t linelen;
 326         int i, ref_is_absolute = (strncmp(refname, "refs/", 5) == 0);
 327
 328         *ref = NULL;
 329
 330         if (ref_is_absolute)
 331                 abs_refname = (char *)refname;
 332         do {
 333                 linelen = getline(&line, &linesize, f);
 334                 if (linelen == -1) {
 335                         if (feof(f))
 336                                 break;
 337                         err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
 338                         break;
 339                 }
 340                 if (linelen > 0 && line[linelen - 1] == '\n')
 341                         line[linelen - 1] = '\0';
 342                 for (i = 0; i < nsubdirs; i++) {
 343                         if (!ref_is_absolute &&
 344                             asprintf(&abs_refname, "refs/%s/%s", subdirs[i],
 345                             refname) == -1)
 346                                 return got_error_from_errno("asprintf");
 347                         err = parse_packed_ref_line(ref, abs_refname, line,
 348                             mtime, algo);
 349                         if (!ref_is_absolute)
 350                                 free(abs_refname);
 351                         if (err || *ref != NULL)
 352                                 break;
 353                 }
 354                 if (err)
 355                         break;
 356         } while (*ref == NULL);
 357         free(line);
 358
 359         return err;
 360 }
 361
 362 static const struct got_error *
 363 open_ref(struct got_reference **ref, const char *path_refs, const char *subdir,
 364     const char *name, int lock, enum got_hash_algorithm algo)
 365 {
 366         const struct got_error *err = NULL;
 367         char *path = NULL;
 368         char *absname = NULL;
 369         int ref_is_absolute = (strncmp(name, "refs/", 5) == 0);
 370         int ref_is_well_known = (subdir[0] == '\0' && is_well_known_ref(name));
 371
 372         *ref = NULL;
 373
 374         if (!got_ref_name_is_valid(name))
 375                 return got_error_path(name, GOT_ERR_BAD_REF_NAME);
 376
 377         if (ref_is_absolute || ref_is_well_known) {
 378                 if (asprintf(&path, "%s/%s", path_refs, name) == -1)
 379                         return got_error_from_errno("asprintf");
 380                 absname = (char *)name;
 381         } else {
 382                 if (asprintf(&path, "%s/%s%s%s", path_refs, subdir,
 383                     subdir[0] ? "/" : "", name) == -1)
 384                         return got_error_from_errno("asprintf");
 385
 386                 if (asprintf(&absname, "refs/%s%s%s",
 387                     subdir, subdir[0] ? "/" : "", name) == -1) {
 388                         err = got_error_from_errno("asprintf");
 389                         goto done;
 390                 }
 391         }
 392
 393         err = parse_ref_file(ref, name, absname, path, lock, algo);
 394 done:
 395         if (!ref_is_absolute && !ref_is_well_known)
 396                 free(absname);
 397         free(path);
 398         return err;
 399 }
 400
 401 const struct got_error *
 402 got_ref_open(struct got_reference **ref, struct got_repository *repo,
 403     const char *refname, int lock)
 404 {
 405         const struct got_error *err = NULL;
 406         char *packed_refs_path = NULL, *path_refs = NULL;
 407         const char *subdirs[] = {
 408             GOT_REF_HEADS, GOT_REF_TAGS, GOT_REF_REMOTES
 409         };
 410         size_t i;
 411         int well_known = is_well_known_ref(refname);
 412         struct got_lockfile *lf = NULL;
 413
 414         *ref = NULL;
 415
 416         path_refs = get_refs_dir_path(repo, refname);
 417         if (path_refs == NULL) {
 418                 err = got_error_from_errno2("get_refs_dir_path", refname);
 419                 goto done;
 420         }
 421
 422         if (well_known) {
 423                 err = open_ref(ref, path_refs, "", refname, lock,
 424                     got_repo_get_object_format(repo));
 425         } else {
 426                 FILE *f;
 427
 428                 /* Search on-disk refs before packed refs! */
 429                 for (i = 0; i < nitems(subdirs); i++) {
 430                         err = open_ref(ref, path_refs, subdirs[i], refname,
 431                             lock, got_repo_get_object_format(repo));
 432                         if ((err && err->code != GOT_ERR_NOT_REF) || *ref)
 433                                 goto done;
 434                 }
 435
 436                 packed_refs_path = got_repo_get_path_packed_refs(repo);
 437                 if (packed_refs_path == NULL) {
 438                         err = got_error_from_errno(
 439                             "got_repo_get_path_packed_refs");
 440                         goto done;
 441                 }
 442
 443                 if (lock) {
 444                         err = got_lockfile_lock(&lf, packed_refs_path, -1);
 445                         if (err)
 446                                 goto done;
 447                 }
 448                 f = fopen(packed_refs_path, "rbe");
 449                 if (f != NULL) {
 450                         struct stat sb;
 451                         if (fstat(fileno(f), &sb) == -1) {
 452                                 err = got_error_from_errno2("fstat",
 453                                     packed_refs_path);
 454                                 goto done;
 455                         }
 456                         err = open_packed_ref(ref, f, subdirs, nitems(subdirs),
 457                             refname, sb.st_mtime,
 458                             got_repo_get_object_format(repo));
 459                         if (!err) {
 460                                 if (fclose(f) == EOF) {
 461                                         err = got_error_from_errno("fclose");
 462                                         got_ref_close(*ref);
 463                                         *ref = NULL;
 464                                 } else if (*ref)
 465                                         (*ref)->lf = lf;
 466                         }
 467                 }
 468         }
 469 done:
 470         if (!err && *ref == NULL)
 471                 err = got_error_not_ref(refname);
 472         if (err && lf)
 473                 got_lockfile_unlock(lf, -1);
 474         free(packed_refs_path);
 475         free(path_refs);
 476         return err;
 477 }
 478
 479 void
 480 got_ref_close(struct got_reference *ref)
 481 {
 482         if (ref->flags & GOT_REF_IS_SYMBOLIC) {
 483                 free(ref->ref.symref.name);
 484                 free(ref->ref.symref.ref);
 485         } else
 486                 free(ref->ref.ref.name);
 487         free(ref);
 488 }
 489
 490 struct got_reference *
 491 got_ref_dup(struct got_reference *ref)
 492 {
 493         struct got_reference *ret;
 494
 495         ret = calloc(1, sizeof(*ret));
 496         if (ret == NULL)
 497                 return NULL;
 498
 499         ret->flags = ref->flags;
 500         if (ref->flags & GOT_REF_IS_SYMBOLIC) {
 501                 ret->ref.symref.name = strdup(ref->ref.symref.name);
 502                 if (ret->ref.symref.name == NULL) {
 503                         free(ret);
 504                         return NULL;
 505                 }
 506                 ret->ref.symref.ref = strdup(ref->ref.symref.ref);
 507                 if (ret->ref.symref.ref == NULL) {
 508                         free(ret->ref.symref.name);
 509                         free(ret);
 510                         return NULL;
 511                 }
 512         } else {
 513                 ret->ref.ref.name = strdup(ref->ref.ref.name);
 514                 if (ret->ref.ref.name == NULL) {
 515                         free(ret);
 516                         return NULL;
 517                 }
 518                 memcpy(&ret->ref.ref.id, &ref->ref.ref.id,
 519                     sizeof(ret->ref.ref.id));
 520         }
 521
 522         return ret;
 523 }
 524
 525 const struct got_error *
 526 got_reflist_entry_dup(struct got_reflist_entry **newp,
 527     struct got_reflist_entry *re)
 528 {
 529         const struct got_error *err = NULL;
 530         struct got_reflist_entry *new;
 531
 532         *newp = NULL;
 533
 534         new = malloc(sizeof(*new));
 535         if (new == NULL)
 536                 return got_error_from_errno("malloc");
 537
 538         new->ref = got_ref_dup(re->ref);
 539         if (new->ref == NULL) {
 540                 err = got_error_from_errno("got_ref_dup");
 541                 free(new);
 542                 return err;
 543         }
 544
 545         *newp = new;
 546         return NULL;
 547 }
 548
 549 const struct got_error *
 550 got_ref_resolve_symbolic(struct got_reference **resolved,
 551     struct got_repository *repo, struct got_reference *ref)
 552 {
 553         struct got_reference *nextref;
 554         const struct got_error *err;
 555
 556         err = got_ref_open(&nextref, repo, ref->ref.symref.ref, 0);
 557         if (err)
 558                 return err;
 559
 560         if (nextref->flags & GOT_REF_IS_SYMBOLIC)
 561                 err = got_ref_resolve_symbolic(resolved, repo, nextref);
 562         else
 563                 *resolved = got_ref_dup(nextref);
 564
 565         got_ref_close(nextref);
 566         return err;
 567 }
 568
 569 static const struct got_error *
 570 ref_resolve(struct got_object_id **id, struct got_repository *repo,
 571     struct got_reference *ref, int recursion)
 572 {
 573         const struct got_error *err;
 574
 575         if (recursion <= 0)
 576                 return got_error_msg(GOT_ERR_RECURSION,
 577                     "reference recursion limit reached");
 578
 579         if (ref->flags & GOT_REF_IS_SYMBOLIC) {
 580                 struct got_reference *resolved = NULL;
 581                 err = got_ref_resolve_symbolic(&resolved, repo, ref);
 582                 if (err == NULL)
 583                         err = ref_resolve(id, repo, resolved, --recursion);
 584                 if (resolved)
 585                         got_ref_close(resolved);
 586                 return err;
 587         }
 588
 589         *id = calloc(1, sizeof(**id));
 590         if (*id == NULL)
 591                 return got_error_from_errno("calloc");
 592         memcpy(*id, &ref->ref.ref.id, sizeof(**id));
 593         return NULL;
 594 }
 595
 596 const struct got_error *
 597 got_ref_resolve(struct got_object_id **id, struct got_repository *repo,
 598     struct got_reference *ref)
 599 {
 600         return ref_resolve(id, repo, ref, GOT_REF_RECURSE_MAX);
 601 }
 602
 603 char *
 604 got_ref_to_str(struct got_reference *ref)
 605 {
 606         char *str;
 607
 608         if (ref->flags & GOT_REF_IS_SYMBOLIC)
 609                 return strdup(ref->ref.symref.ref);
 610
 611         if (got_object_id_str(&str, &ref->ref.ref.id) != NULL)
 612                 return NULL;
 613
 614         return str;
 615 }
 616
 617 const char *
 618 got_ref_get_name(struct got_reference *ref)
 619 {
 620         if (ref->flags & GOT_REF_IS_SYMBOLIC)
 621                 return ref->ref.symref.name;
 622
 623         return ref->ref.ref.name;
 624 }
 625
 626 const char *
 627 got_ref_get_symref_target(struct got_reference *ref)
 628 {
 629         if (ref->flags & GOT_REF_IS_SYMBOLIC)
 630                 return ref->ref.symref.ref;
 631
 632         return NULL;
 633 }
 634
 635 time_t
 636 got_ref_get_mtime(struct got_reference *ref)
 637 {
 638         return ref->mtime;
 639 }
 640
 641 const struct got_error *
 642 got_ref_cmp_by_name(void *arg, int *cmp, struct got_reference *re1,
 643     struct got_reference* re2)
 644 {
 645         const char *name1 = got_ref_get_name(re1);
 646         const char *name2 = got_ref_get_name(re2);
 647
 648         *cmp = got_path_cmp(name1, name2, strlen(name1), strlen(name2));
 649         return NULL;
 650 }
 651
 652 const struct got_error *
 653 got_ref_cmp_tags(void *arg, int *cmp, struct got_reference *ref1,
 654     struct got_reference *ref2)
 655 {
 656         const struct got_error *err = NULL;
 657         struct got_repository *repo = arg;
 658         struct got_object_id *id1, *id2 = NULL;
 659         struct got_tag_object *tag1 = NULL, *tag2 = NULL;
 660         struct got_commit_object *commit1 = NULL, *commit2 = NULL;
 661         time_t time1, time2;
 662
 663         *cmp = 0;
 664
 665         err = got_ref_resolve(&id1, repo, ref1);
 666         if (err)
 667                 return err;
 668         err = got_object_open_as_tag(&tag1, repo, id1);
 669         if (err) {
 670                 if (err->code != GOT_ERR_OBJ_TYPE)
 671                         goto done;
 672                 /* "lightweight" tag */
 673                 err = got_object_open_as_commit(&commit1, repo, id1);
 674                 if (err)
 675                         goto done;
 676                 time1 = got_object_commit_get_committer_time(commit1);
 677         } else
 678                 time1 = got_object_tag_get_tagger_time(tag1);
 679
 680         err = got_ref_resolve(&id2, repo, ref2);
 681         if (err)
 682                 goto done;
 683         err = got_object_open_as_tag(&tag2, repo, id2);
 684         if (err) {
 685                 if (err->code != GOT_ERR_OBJ_TYPE)
 686                         goto done;
 687                 /* "lightweight" tag */
 688                 err = got_object_open_as_commit(&commit2, repo, id2);
 689                 if (err)
 690                         goto done;
 691                 time2 = got_object_commit_get_committer_time(commit2);
 692         } else
 693                 time2 = got_object_tag_get_tagger_time(tag2);
 694
 695         /* Put latest tags first. */
 696         if (time1 < time2)
 697                 *cmp = 1;
 698         else if (time1 > time2)
 699                 *cmp = -1;
 700         else
 701                 err = got_ref_cmp_by_name(NULL, cmp, ref2, ref1);
 702 done:
 703         free(id1);
 704         free(id2);
 705         if (tag1)
 706                 got_object_tag_close(tag1);
 707         if (tag2)
 708                 got_object_tag_close(tag2);
 709         if (commit1)
 710                 got_object_commit_close(commit1);
 711         if (commit2)
 712                 got_object_commit_close(commit2);
 713         return err;
 714 }
 715
 716 static const struct got_error *
 717 get_committer_time(struct got_reference *ref, struct got_repository *repo)
 718 {
 719         const struct got_error *err = NULL;
 720         int obj_type;
 721         struct got_commit_object *commit = NULL;
 722         struct got_tag_object *tag = NULL;
 723         struct got_object_id *id = NULL;
 724
 725         err = got_ref_resolve(&id, repo, ref);
 726         if (err)
 727                 return err;
 728
 729         err = got_object_get_type(&obj_type, repo, id);
 730         if (err)
 731                 goto done;
 732
 733         switch (obj_type) {
 734         case GOT_OBJ_TYPE_COMMIT:
 735                 err = got_object_open_as_commit(&commit, repo, id);
 736                 if (err)
 737                         goto done;
 738                 ref->committer_time =
 739                     got_object_commit_get_committer_time(commit);
 740                 break;
 741         case GOT_OBJ_TYPE_TAG:
 742                 err = got_object_open_as_tag(&tag, repo, id);
 743                 if (err)
 744                         goto done;
 745                 ref->committer_time = got_object_tag_get_tagger_time(tag);
 746                 break;
 747         default:
 748                 /* best effort for other object types */
 749                 ref->committer_time = got_ref_get_mtime(ref);
 750                 break;
 751         }
 752 done:
 753         free(id);
 754         if (commit)
 755                 got_object_commit_close(commit);
 756         if (tag)
 757                 got_object_tag_close(tag);
 758         return err;
 759 }
 760
 761 const struct got_error *
 762 got_ref_cmp_by_commit_timestamp_descending(void *arg, int *cmp,
 763     struct got_reference *ref1, struct got_reference *ref2)
 764 {
 765         const struct got_error *err = NULL;
 766         struct got_repository *repo = arg;
 767
 768         *cmp = 0;
 769
 770         if (ref1->committer_time == 0) {
 771                 err = get_committer_time(ref1, repo);
 772                 if (err)
 773                         return err;
 774         }
 775         if (ref2->committer_time == 0) {
 776                 err = get_committer_time(ref2, repo);
 777                 if (err)
 778                         return err;
 779         }
 780
 781         if (ref1->committer_time < ref2->committer_time)
 782                 *cmp = 1;
 783         else if (ref2->committer_time < ref1->committer_time)
 784                 *cmp = -1;
 785         else
 786                 return got_ref_cmp_by_name(arg, cmp, ref1, ref2);
 787
 788         return err;
 789 }
 790
 791 const struct got_error *
 792 got_reflist_insert(struct got_reflist_entry **newp,
 793     struct got_reflist_head *refs, struct got_reference *ref,
 794     got_ref_cmp_cb cmp_cb, void *cmp_arg)
 795 {
 796         const struct got_error *err;
 797         struct got_reflist_entry *new, *re;
 798         int cmp;
 799
 800         *newp = NULL;
 801
 802         if (cmp_cb != got_ref_cmp_by_name && (ref->flags & GOT_REF_IS_PACKED)) {
 803                 /*
 804                  * If we are not sorting elements by name then we must still
 805                  * detect collisions between a packed ref and an on-disk ref
 806                  * using the same name. On-disk refs take precedence and are
 807                  * already present on the list before packed refs get added.
 808                  */
 809                 TAILQ_FOREACH(re, refs, entry) {
 810                         err = got_ref_cmp_by_name(NULL, &cmp, re->ref, ref);
 811                         if (err)
 812                                 return err;
 813                         if (cmp == 0)
 814                                 return NULL;
 815                 }
 816         }
 817
 818         new = malloc(sizeof(*new));
 819         if (new == NULL)
 820                 return got_error_from_errno("malloc");
 821         new->ref = ref;
 822         *newp = new;
 823
 824         /*
 825          * We must de-duplicate entries on insert because packed-refs may
 826          * contain redundant entries. On-disk refs take precedence.
 827          * This code assumes that on-disk revs are read before packed-refs.
 828          * We're iterating the list anyway, so insert elements sorted by name.
 829          *
 830          * Many callers will provide paths in a somewhat sorted order.
 831          * Iterating backwards from the tail of the list should be more
 832          * efficient than traversing through the entire list each time
 833          * an element is inserted.
 834          */
 835         re = TAILQ_LAST(refs, got_reflist_head);
 836         while (re) {
 837                 err = (*cmp_cb)(cmp_arg, &cmp, re->ref, new->ref);
 838                 if (err)
 839                         return err;
 840                 if (cmp == 0) {
 841                         /* duplicate */
 842                         free(new);
 843                         *newp = NULL;
 844                         return NULL;
 845                 } else if (cmp < 0) {
 846                         TAILQ_INSERT_AFTER(refs, re, new, entry);
 847                         return NULL;
 848                 }
 849                 re = TAILQ_PREV(re, got_reflist_head, entry);
 850         }
 851
 852         TAILQ_INSERT_HEAD(refs, new, entry);
 853         return NULL;
 854 }
 855
 856 const struct got_error *
 857 got_reflist_sort(struct got_reflist_head *refs,
 858     got_ref_cmp_cb cmp_cb, void *cmp_arg)
 859 {
 860         const struct got_error *err = NULL;
 861         struct got_reflist_entry *re, *tmp, *new;
 862         struct got_reflist_head sorted;
 863
 864         TAILQ_INIT(&sorted);
 865
 866         TAILQ_FOREACH_SAFE(re, refs, entry, tmp) {
 867                 struct got_reference *ref = re->ref;
 868                 TAILQ_REMOVE(refs, re, entry);
 869                 free(re);
 870                 err = got_reflist_insert(&new, &sorted, ref, cmp_cb, cmp_arg);
 871                 if (err || new == NULL /* duplicate */)
 872                         got_ref_close(ref);
 873                 if (err)
 874                         return err;
 875         }
 876
 877         TAILQ_CONCAT(refs, &sorted, entry);
 878         return NULL;
 879 }
 880
 881 static const struct got_error *
 882 gather_on_disk_refs(struct got_reflist_head *refs, const char *path_refs,
 883     const char *subdir, struct got_repository *repo,
 884     got_ref_cmp_cb cmp_cb, void *cmp_arg)
 885 {
 886         const struct got_error *err = NULL;
 887         DIR *d = NULL;
 888         char *path_subdir;
 889
 890         while (subdir[0] == '/')
 891                 subdir++;
 892
 893         if (asprintf(&path_subdir, "%s/%s", path_refs, subdir) == -1)
 894                 return got_error_from_errno("asprintf");
 895
 896         d = opendir(path_subdir);
 897         if (d == NULL)
 898                 goto done;
 899
 900         for (;;) {
 901                 struct dirent *dent;
 902                 struct got_reference *ref;
 903                 char *child;
 904                 int type;
 905
 906                 dent = readdir(d);
 907                 if (dent == NULL)
 908                         break;
 909
 910                 if (strcmp(dent->d_name, ".") == 0 ||
 911                     strcmp(dent->d_name, "..") == 0)
 912                         continue;
 913
 914                 err = got_path_dirent_type(&type, path_subdir, dent);
 915                 if (err)
 916                         break;
 917
 918                 switch (type) {
 919                 case DT_REG:
 920                         err = open_ref(&ref, path_refs, subdir, dent->d_name,
 921                             0, got_repo_get_object_format(repo));
 922                         if (err && err->code == GOT_ERR_BAD_REF_NAME)
 923                                 break;
 924                         if (err)
 925                                 goto done;
 926                         if (ref) {
 927                                 struct got_reflist_entry *new;
 928                                 err = got_reflist_insert(&new, refs, ref,
 929                                     cmp_cb, cmp_arg);
 930                                 if (err || new == NULL /* duplicate */)
 931                                         got_ref_close(ref);
 932                                 if (err)
 933                                         goto done;
 934                         }
 935                         break;
 936                 case DT_DIR:
 937                         if (asprintf(&child, "%s%s%s", subdir,
 938                             subdir[0] == '\0' ? "" : "/", dent->d_name) == -1) {
 939                                 err = got_error_from_errno("asprintf");
 940                                 break;
 941                         }
 942                         err = gather_on_disk_refs(refs, path_refs, child, repo,
 943                             cmp_cb, cmp_arg);
 944                         free(child);
 945                         break;
 946                 default:
 947                         break;
 948                 }
 949         }
 950 done:
 951         if (d)
 952                 closedir(d);
 953         free(path_subdir);
 954         return err;
 955 }
 956
 957 const struct got_error *
 958 got_ref_list(struct got_reflist_head *refs, struct got_repository *repo,
 959     const char *ref_namespace, got_ref_cmp_cb cmp_cb, void *cmp_arg)
 960 {
 961         const struct got_error *err;
 962         char *packed_refs_path = NULL, *path_refs = NULL;
 963         char *abs_namespace = NULL, *buf = NULL;
 964         const char *ondisk_ref_namespace = NULL;
 965         char *line = NULL;
 966         FILE *f = NULL;
 967         struct got_reference *ref;
 968         struct got_reflist_entry *new;
 969
 970         if (ref_namespace == NULL || ref_namespace[0] == '\0') {
 971                 path_refs = get_refs_dir_path(repo, GOT_REF_HEAD);
 972                 if (path_refs == NULL) {
 973                         err = got_error_from_errno("get_refs_dir_path");
 974                         goto done;
 975                 }
 976                 err = open_ref(&ref, path_refs, "", GOT_REF_HEAD, 0,
 977                     got_repo_get_object_format(repo));
 978                 if (err)
 979                         goto done;
 980                 err = got_reflist_insert(&new, refs, ref, cmp_cb, cmp_arg);
 981                 if (err || new == NULL /* duplicate */)
 982                         got_ref_close(ref);
 983                 if (err && err->code != GOT_ERR_NOT_REF)
 984                         goto done;
 985         } else {
 986                 /* Try listing a single reference. */
 987                 const char *refname = ref_namespace;
 988                 path_refs = get_refs_dir_path(repo, refname);
 989                 if (path_refs == NULL) {
 990                         err = got_error_from_errno("get_refs_dir_path");
 991                         goto done;
 992                 }
 993                 err = open_ref(&ref, path_refs, "", refname, 0,
 994                     got_repo_get_object_format(repo));
 995                 if (err) {
 996                         if (err->code != GOT_ERR_NOT_REF)
 997                                 goto done;
 998                         /* Try to look up references in a given namespace. */
 999                 } else {
1000                         err = got_reflist_insert(&new, refs, ref,
1001                             cmp_cb, cmp_arg);
1002                         if (err || new == NULL /* duplicate */)
1003                                 got_ref_close(ref);
1004                         return err;
1005                 }
1006         }
1007
1008         if (ref_namespace) {
1009                 size_t len;
1010                 /* Canonicalize the path to eliminate double-slashes if any. */
1011                 if (asprintf(&abs_namespace, "/%s", ref_namespace) == -1) {
1012                         err = got_error_from_errno("asprintf");
1013                         goto done;
1014                 }
1015                 len = strlen(abs_namespace) + 1;
1016                 buf = malloc(len);
1017                 if (buf == NULL) {
1018                         err = got_error_from_errno("malloc");
1019                         goto done;
1020                 }
1021                 err = got_canonpath(abs_namespace, buf, len);
1022                 if (err)
1023                         goto done;
1024                 ondisk_ref_namespace = buf;
1025                 while (ondisk_ref_namespace[0] == '/')
1026                         ondisk_ref_namespace++;
1027                 if (strncmp(ondisk_ref_namespace, "refs/", 5) == 0)
1028                         ondisk_ref_namespace += 5;
1029                 else if (strcmp(ondisk_ref_namespace, "refs") == 0)
1030                         ondisk_ref_namespace = "";
1031         }
1032
1033         /* Gather on-disk refs before parsing packed-refs. */
1034         free(path_refs);
1035         path_refs = get_refs_dir_path(repo, "");
1036         if (path_refs == NULL) {
1037                 err = got_error_from_errno("get_refs_dir_path");
1038                 goto done;
1039         }
1040         err = gather_on_disk_refs(refs, path_refs,
1041             ondisk_ref_namespace ? ondisk_ref_namespace : "", repo,
1042             cmp_cb, cmp_arg);
1043         if (err)
1044                 goto done;
1045
1046         /*
1047          * The packed-refs file may contain redundant entries, in which
1048          * case on-disk refs take precedence.
1049          */
1050         packed_refs_path = got_repo_get_path_packed_refs(repo);
1051         if (packed_refs_path == NULL) {
1052                 err = got_error_from_errno("got_repo_get_path_packed_refs");
1053                 goto done;
1054         }
1055
1056         f = fopen(packed_refs_path, "re");
1057         if (f) {
1058                 size_t linesize = 0;
1059                 ssize_t linelen;
1060                 struct stat sb;
1061
1062                 if (fstat(fileno(f), &sb) == -1) {
1063                         err = got_error_from_errno2("fstat", packed_refs_path);
1064                         goto done;
1065                 }
1066                 for (;;) {
1067                         linelen = getline(&line, &linesize, f);
1068                         if (linelen == -1) {
1069                                 if (feof(f))
1070                                         break;
1071                                 err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
1072                                 goto done;
1073                         }
1074                         if (linelen > 0 && line[linelen - 1] == '\n')
1075                                 line[linelen - 1] = '\0';
1076                         err = parse_packed_ref_line(&ref, NULL, line,
1077                             sb.st_mtime, got_repo_get_object_format(repo));
1078                         if (err)
1079                                 goto done;
1080                         if (ref) {
1081                                 if (ref_namespace) {
1082                                         const char *name;
1083                                         name = got_ref_get_name(ref);
1084                                         if (!got_path_is_child(name,
1085                                             ref_namespace,
1086                                             strlen(ref_namespace))) {
1087                                                 got_ref_close(ref);
1088                                                 continue;
1089                                         }
1090                                 }
1091                                 err = got_reflist_insert(&new, refs, ref,
1092                                     cmp_cb, cmp_arg);
1093                                 if (err || new == NULL /* duplicate */)
1094                                         got_ref_close(ref);
1095                                 if (err)
1096                                         goto done;
1097                         }
1098                 }
1099         }
1100 done:
1101         free(packed_refs_path);
1102         free(abs_namespace);
1103         free(buf);
1104         free(line);
1105         free(path_refs);
1106         if (f && fclose(f) == EOF && err == NULL)
1107                 err = got_error_from_errno("fclose");
1108         return err;
1109 }
1110
1111 void
1112 got_ref_list_free(struct got_reflist_head *refs)
1113 {
1114         struct got_reflist_entry *re;
1115
1116         while ((re = TAILQ_FIRST(refs))) {
1117                 TAILQ_REMOVE(refs, re, entry);
1118                 got_ref_close(re->ref);
1119                 free(re);
1120         }
1121 }
1122
1123 int
1124 got_ref_is_symbolic(struct got_reference *ref)
1125 {
1126         return (ref->flags & GOT_REF_IS_SYMBOLIC);
1127 }
1128
1129 const struct got_error *
1130 got_ref_change_ref(struct got_reference *ref, struct got_object_id *id)
1131 {
1132         if (ref->flags & GOT_REF_IS_SYMBOLIC)
1133                 return got_error(GOT_ERR_BAD_REF_TYPE);
1134
1135         memcpy(&ref->ref.ref.id, id, sizeof(ref->ref.ref.id));
1136         return NULL;
1137 }
1138
1139 const struct got_error *
1140 got_ref_change_symref(struct got_reference *ref, const char *refname)
1141 {
1142         char *new_name;
1143
1144         if ((ref->flags & GOT_REF_IS_SYMBOLIC) == 0)
1145                 return got_error(GOT_ERR_BAD_REF_TYPE);
1146
1147         new_name = strdup(refname);
1148         if (new_name == NULL)
1149                 return got_error_from_errno("strdup");
1150
1151         free(ref->ref.symref.ref);
1152         ref->ref.symref.ref = new_name;
1153         return NULL;
1154 }
1155
1156 const struct got_error *
1157 got_ref_change_symref_to_ref(struct got_reference *symref,
1158     struct got_object_id *id)
1159 {
1160         if ((symref->flags & GOT_REF_IS_SYMBOLIC) == 0)
1161                 return got_error(GOT_ERR_BAD_REF_TYPE);
1162
1163         symref->ref.ref.name = symref->ref.symref.name;
1164         memcpy(&symref->ref.ref.id, id, sizeof(symref->ref.ref.id));
1165         symref->flags &= ~GOT_REF_IS_SYMBOLIC;
1166         return NULL;
1167 }
1168
1169 const struct got_error *
1170 got_ref_write(struct got_reference *ref, struct got_repository *repo)
1171 {
1172         const struct got_error *err = NULL, *unlock_err = NULL;
1173         const char *name = got_ref_get_name(ref);
1174         char *path_refs = NULL, *path = NULL, *tmppath = NULL;
1175         struct got_lockfile *lf = NULL;
1176         FILE *f = NULL;
1177         size_t n;
1178         struct stat sb;
1179
1180         path_refs = get_refs_dir_path(repo, name);
1181         if (path_refs == NULL) {
1182                 err = got_error_from_errno2("get_refs_dir_path", name);
1183                 goto done;
1184         }
1185
1186         if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
1187                 err = got_error_from_errno("asprintf");
1188                 goto done;
1189         }
1190
1191         err = got_opentemp_named(&tmppath, &f, path, "");
1192         if (err) {
1193                 char *parent;
1194                 if (!(err->code == GOT_ERR_ERRNO && errno == ENOENT))
1195                         goto done;
1196                 err = got_path_dirname(&parent, path);
1197                 if (err)
1198                         goto done;
1199                 err = got_path_mkdir(parent);
1200                 free(parent);
1201                 if (err)
1202                         goto done;
1203                 err = got_opentemp_named(&tmppath, &f, path, "");
1204                 if (err)
1205                         goto done;
1206         }
1207
1208         if (ref->flags & GOT_REF_IS_SYMBOLIC) {
1209                 n = fprintf(f, "ref: %s\n", ref->ref.symref.ref);
1210                 if (n != strlen(ref->ref.symref.ref) + 6) {
1211                         err = got_ferror(f, GOT_ERR_IO);
1212                         goto done;
1213                 }
1214         } else {
1215                 char *hex;
1216                 size_t len;
1217
1218                 err = got_object_id_str(&hex, &ref->ref.ref.id);
1219                 if (err)
1220                         goto done;
1221                 len = strlen(hex);
1222                 n = fprintf(f, "%s\n", hex);
1223                 free(hex);
1224                 if (n != len + 1) {
1225                         err = got_ferror(f, GOT_ERR_IO);
1226                         goto done;
1227                 }
1228         }
1229
1230         if (ref->lf == NULL) {
1231                 err = got_lockfile_lock(&lf, path, -1);
1232                 if (err)
1233                         goto done;
1234         }
1235
1236         /* XXX: check if old content matches our expectations? */
1237
1238         if (stat(path, &sb) != 0) {
1239                 if (errno != ENOENT) {
1240                         err = got_error_from_errno2("stat", path);
1241                         goto done;
1242                 }
1243                 sb.st_mode = GOT_DEFAULT_FILE_MODE;
1244         }
1245
1246         if (fchmod(fileno(f), sb.st_mode) != 0) {
1247                 err = got_error_from_errno2("fchmod", tmppath);
1248                 goto done;
1249         }
1250
1251         if (rename(tmppath, path) != 0) {
1252                 err = got_error_from_errno3("rename", tmppath, path);
1253                 goto done;
1254         }
1255         free(tmppath);
1256         tmppath = NULL;
1257
1258         if (stat(path, &sb) == -1) {
1259                 err = got_error_from_errno2("stat", path);
1260                 goto done;
1261         }
1262         ref->mtime = sb.st_mtime;
1263 done:
1264         if (ref->lf == NULL && lf)
1265                 unlock_err = got_lockfile_unlock(lf, -1);
1266         if (f) {
1267                 if (fclose(f) == EOF && err == NULL)
1268                         err = got_error_from_errno("fclose");
1269         }
1270         free(path_refs);
1271         free(path);
1272         if (tmppath) {
1273                 if (unlink(tmppath) == -1 && err == NULL)
1274                         err = got_error_from_errno2("unlink", tmppath);
1275                 free(tmppath);
1276         }
1277         return err ? err : unlock_err;
1278 }
1279
1280 static const struct got_error *
1281 delete_packed_ref(struct got_reference *delref, struct got_repository *repo)
1282 {
1283         const struct got_error *err = NULL, *unlock_err = NULL;
1284         struct got_lockfile *lf = NULL;
1285         FILE *f = NULL, *tmpf = NULL;
1286         char *line = NULL, *packed_refs_path, *tmppath = NULL;
1287         size_t linesize = 0;
1288         struct got_reflist_head refs;
1289         int found_delref = 0;
1290
1291         /* The packed-refs file does not cotain symbolic references. */
1292         if (delref->flags & GOT_REF_IS_SYMBOLIC)
1293                 return got_error(GOT_ERR_BAD_REF_DATA);
1294
1295         TAILQ_INIT(&refs);
1296
1297         packed_refs_path = got_repo_get_path_packed_refs(repo);
1298         if (packed_refs_path == NULL)
1299                 return got_error_from_errno("got_repo_get_path_packed_refs");
1300
1301         err = got_opentemp_named(&tmppath, &tmpf, packed_refs_path, "");
1302         if (err)
1303                 goto done;
1304
1305         if (delref->lf == NULL) {
1306                 err = got_lockfile_lock(&lf, packed_refs_path, -1);
1307                 if (err)
1308                         goto done;
1309         }
1310
1311         f = fopen(packed_refs_path, "re");
1312         if (f == NULL) {
1313                 err = got_error_from_errno2("fopen", packed_refs_path);
1314                 goto done;
1315         }
1316         for (;;) {
1317                 ssize_t linelen;
1318                 struct got_reference *ref;
1319                 struct got_reflist_entry *new;
1320
1321                 linelen = getline(&line, &linesize, f);
1322                 if (linelen == -1) {
1323                         if (feof(f))
1324                                 break;
1325                         err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
1326                         goto done;
1327                 }
1328                 if (linelen > 0 && line[linelen - 1] == '\n')
1329                         line[linelen - 1] = '\0';
1330                 err = parse_packed_ref_line(&ref, NULL, line, 0,
1331                     got_repo_get_object_format(repo));
1332                 if (err)
1333                         goto done;
1334                 if (ref == NULL)
1335                         continue;
1336
1337                 if (strcmp(ref->ref.ref.name, delref->ref.ref.name) == 0 &&
1338                     got_object_id_cmp(&ref->ref.ref.id,
1339                     &delref->ref.ref.id) == 0) {
1340                         found_delref = 1;
1341                         got_ref_close(ref);
1342                         continue;
1343                 }
1344
1345                 err = got_reflist_insert(&new, &refs, ref,
1346                     got_ref_cmp_by_name, NULL);
1347                 if (err || new == NULL /* duplicate */)
1348                         got_ref_close(ref);
1349                 if (err)
1350                         goto done;
1351         }
1352
1353         if (found_delref) {
1354                 struct got_reflist_entry *re;
1355                 size_t n;
1356                 struct stat sb;
1357
1358                 n = fprintf(tmpf, "%s\n", GOT_PACKED_REFS_HEADER);
1359                 if (n != sizeof(GOT_PACKED_REFS_HEADER)) {
1360                         err = got_ferror(f, GOT_ERR_IO);
1361                         goto done;
1362                 }
1363
1364                 TAILQ_FOREACH(re, &refs, entry) {
1365                         char *hex;
1366                         size_t len;
1367
1368                         err = got_object_id_str(&hex, &re->ref->ref.ref.id);
1369                         if (err)
1370                                 goto done;
1371                         len = strlen(hex);
1372                         n = fprintf(tmpf, "%s ", hex);
1373                         free(hex);
1374                         if (n != len + 1) {
1375                                 err = got_ferror(f, GOT_ERR_IO);
1376                                 goto done;
1377                         }
1378
1379                         n = fprintf(tmpf, "%s\n", re->ref->ref.ref.name);
1380                         if (n != strlen(re->ref->ref.ref.name) + 1) {
1381                                 err = got_ferror(f, GOT_ERR_IO);
1382                                 goto done;
1383                         }
1384                 }
1385
1386                 if (fflush(tmpf) != 0) {
1387                         err = got_error_from_errno("fflush");
1388                         goto done;
1389                 }
1390
1391                 if (fstat(fileno(f), &sb) != 0) {
1392                         if (errno != ENOENT) {
1393                                 err = got_error_from_errno2("fstat",
1394                                     packed_refs_path);
1395                                 goto done;
1396                         }
1397                         sb.st_mode = GOT_DEFAULT_FILE_MODE;
1398                 }
1399
1400                 if (fchmod(fileno(tmpf), sb.st_mode) != 0) {
1401                         err = got_error_from_errno2("fchmod", tmppath);
1402                         goto done;
1403                 }
1404
1405                 if (rename(tmppath, packed_refs_path) != 0) {
1406                         err = got_error_from_errno3("rename", tmppath,
1407                             packed_refs_path);
1408                         goto done;
1409                 }
1410                 free(tmppath);
1411                 tmppath = NULL;
1412         }
1413 done:
1414         if (delref->lf == NULL && lf)
1415                 unlock_err = got_lockfile_unlock(lf, -1);
1416         if (f) {
1417                 if (fclose(f) == EOF && err == NULL)
1418                         err = got_error_from_errno("fclose");
1419         }
1420         if (tmppath && unlink(tmppath) == -1 && err == NULL)
1421                 err = got_error_from_errno2("unlink", tmppath);
1422         if (tmpf && fclose(tmpf) == EOF && err == NULL)
1423                 err = got_error_from_errno("fclose");
1424         free(tmppath);
1425         free(packed_refs_path);
1426         free(line);
1427         got_ref_list_free(&refs);
1428         return err ? err : unlock_err;
1429 }
1430
1431 static const struct got_error *
1432 delete_loose_ref(struct got_reference *ref, struct got_repository *repo)
1433 {
1434         const struct got_error *err = NULL, *unlock_err = NULL;
1435         const char *name = got_ref_get_name(ref);
1436         char *path_refs = NULL, *path = NULL;
1437         struct got_lockfile *lf = NULL;
1438
1439         path_refs = get_refs_dir_path(repo, name);
1440         if (path_refs == NULL) {
1441                 err = got_error_from_errno2("get_refs_dir_path", name);
1442                 goto done;
1443         }
1444
1445         if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
1446                 err = got_error_from_errno("asprintf");
1447                 goto done;
1448         }
1449
1450         if (ref->lf == NULL) {
1451                 err = got_lockfile_lock(&lf, path, -1);
1452                 if (err)
1453                         goto done;
1454         }
1455
1456         /* XXX: check if old content matches our expectations? */
1457
1458         if (unlink(path) == -1)
1459                 err = got_error_from_errno2("unlink", path);
1460 done:
1461         if (ref->lf == NULL && lf)
1462                 unlock_err = got_lockfile_unlock(lf, -1);
1463
1464         free(path_refs);
1465         free(path);
1466         return err ? err : unlock_err;
1467 }
1468
1469 const struct got_error *
1470 got_ref_delete(struct got_reference *ref, struct got_repository *repo)
1471 {
1472         const struct got_error *err = NULL;
1473         struct got_reference *ref2;
1474
1475         if (ref->flags & GOT_REF_IS_PACKED) {
1476                 err = delete_packed_ref(ref, repo);
1477                 if (err)
1478                         return err;
1479
1480                 err = got_ref_open(&ref2, repo, got_ref_get_name(ref), 0);
1481                 if (err) {
1482                         if (err->code == GOT_ERR_NOT_REF)
1483                                 return NULL;
1484                         return err;
1485                 }
1486
1487                 err = delete_loose_ref(ref2, repo);
1488                 got_ref_close(ref2);
1489                 return err;
1490         } else {
1491                 err = delete_loose_ref(ref, repo);
1492                 if (err)
1493                         return err;
1494
1495                 err = got_ref_open(&ref2, repo, got_ref_get_name(ref), 0);
1496                 if (err) {
1497                         if (err->code == GOT_ERR_NOT_REF)
1498                                 return NULL;
1499                         return err;
1500                 }
1501
1502                 err = delete_packed_ref(ref2, repo);
1503                 got_ref_close(ref2);
1504                 return err;
1505         }
1506 }
1507
1508 const struct got_error *
1509 got_ref_unlock(struct got_reference *ref)
1510 {
1511         const struct got_error *err;
1512         err = got_lockfile_unlock(ref->lf, -1);
1513         ref->lf = NULL;
1514         return err;
1515 }
1516
1517 struct got_reflist_object_id_map {
1518         struct got_object_idset *idset;
1519 };
1520
1521 struct got_reflist_object_id_map_entry {
1522         struct got_reflist_head refs;
1523 };
1524
1525 static const struct got_error *
1526 add_object_id_map_entry(struct got_object_idset *idset,
1527     struct got_object_id *id, struct got_reflist_entry *re)
1528 {
1529         const struct got_error *err = NULL;
1530         struct got_reflist_object_id_map_entry *ent;
1531         struct got_reflist_entry *new;
1532
1533         ent = got_object_idset_get(idset, id);
1534         if (ent == NULL) {
1535                 ent = malloc(sizeof(*ent));
1536                 if (ent == NULL)
1537                         return got_error_from_errno("malloc");
1538
1539                 TAILQ_INIT(&ent->refs);
1540                 err = got_object_idset_add(idset, id, ent);
1541                 if (err) {
1542                         free(ent);
1543                         return err;
1544                 }
1545         }
1546
1547         err = got_reflist_entry_dup(&new, re);
1548         if (err)
1549                 return err;
1550
1551         TAILQ_INSERT_TAIL(&ent->refs, new, entry);
1552         return NULL;
1553 }
1554
1555 const struct got_error *
1556 got_reflist_object_id_map_create(struct got_reflist_object_id_map **map,
1557     struct got_reflist_head *refs, struct got_repository *repo)
1558 {
1559         const struct got_error *err = NULL;
1560         struct got_object_idset *idset;
1561         struct got_object_id *id = NULL;
1562         struct got_reflist_entry *re;
1563
1564         idset = got_object_idset_alloc();
1565         if (idset == NULL)
1566                 return got_error_from_errno("got_object_idset_alloc");
1567
1568         *map = malloc(sizeof(**map));
1569         if (*map == NULL) {
1570                 got_object_idset_free(idset);
1571                 return got_error_from_errno("malloc");
1572         }
1573         (*map)->idset = idset;
1574
1575         TAILQ_FOREACH(re, refs, entry) {
1576                 struct got_tag_object *tag = NULL;
1577
1578                 err = got_ref_resolve(&id, repo, re->ref);
1579                 if (err)
1580                         goto done;
1581
1582                 err = add_object_id_map_entry(idset, id, re);
1583                 if (err)
1584                         goto done;
1585
1586                 if (strstr(got_ref_get_name(re->ref), "/tags/") == NULL) {
1587                         free(id);
1588                         id = NULL;
1589                         continue;
1590                 }
1591
1592                 err = got_object_open_as_tag(&tag, repo, id);
1593                 if (err) {
1594                         if (err->code != GOT_ERR_OBJ_TYPE)
1595                                 goto done;
1596                         /* Ref points at something other than a tag. */
1597                         err = NULL;
1598                         tag = NULL;
1599                         free(id);
1600                         id = NULL;
1601                         continue;
1602                 }
1603
1604                 err = add_object_id_map_entry(idset,
1605                     got_object_tag_get_object_id(tag), re);
1606                 got_object_tag_close(tag);
1607                 if (err)
1608                         goto done;
1609
1610                 free(id);
1611                 id = NULL;
1612         }
1613 done:
1614         free(id);
1615         if (err) {
1616                 got_reflist_object_id_map_free(*map);
1617                 *map = NULL;
1618         }
1619         return err;
1620 }
1621
1622 struct got_reflist_head *
1623 got_reflist_object_id_map_lookup(struct got_reflist_object_id_map *map,
1624     struct got_object_id *id)
1625 {
1626         struct got_reflist_object_id_map_entry *ent;
1627         ent = got_object_idset_get(map->idset, id);
1628         if (ent)
1629                 return &ent->refs;
1630         return NULL;
1631 }
1632
1633 static const struct got_error *
1634 free_id_map_entry(struct got_object_id *id, void *data, void *arg)
1635 {
1636         struct got_reflist_object_id_map_entry *ent = data;
1637
1638         got_ref_list_free(&ent->refs);
1639         free(ent);
1640         return NULL;
1641 }
1642
1643 void
1644 got_reflist_object_id_map_free(struct got_reflist_object_id_map *map)
1645 {
1646         got_object_idset_for_each(map->idset, free_id_map_entry, NULL);
1647         got_object_idset_free(map->idset);
1648         free(map);
1649 }