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 <sys/types.h>
  18 #include <sys/queue.h>
  19 #include <sys/stat.h>
  20
  21 #include <errno.h>
  22 #include <dirent.h>
  23 #include <limits.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <unistd.h>
  28 #include <zlib.h>
  29 #include <time.h>
  30 #include <libgen.h>
  31
  32 #include "got_compat.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)
 156 {
 157         enum got_hash_algorithm algo = GOT_HASH_SHA1;
 158         struct got_object_id id;
 159
 160         if (strncmp(line, "ref: ", 5) == 0) {
 161                 line += 5;
 162                 return parse_symref(ref, name, line);
 163         }
 164
 165         if (!got_parse_object_id(&id, line, algo))
 166                 return got_error(GOT_ERR_BAD_REF_DATA);
 167
 168         return alloc_ref(ref, name, &id, 0, mtime);
 169 }
 170
 171 static const struct got_error *
 172 parse_ref_file(struct got_reference **ref, const char *name,
 173     const char *absname, const char *abspath, int lock)
 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);
 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)
 294 {
 295         enum got_hash_algorithm algo = GOT_HASH_SHA1;
 296         struct got_object_id id;
 297         const char *name;
 298
 299         *ref = NULL;
 300
 301         if (line[0] == '#' || line[0] == '^')
 302                 return NULL;
 303
 304         if (!got_parse_object_id(&id, line, algo))
 305                 return got_error(GOT_ERR_BAD_REF_DATA);
 306
 307         if (abs_refname) {
 308                 if (strcmp(line + SHA1_DIGEST_STRING_LENGTH, abs_refname) != 0)
 309                         return NULL;
 310                 name = abs_refname;
 311         } else
 312                 name = line + SHA1_DIGEST_STRING_LENGTH;
 313
 314         return alloc_ref(ref, name, &id, GOT_REF_IS_PACKED, mtime);
 315 }
 316
 317 static const struct got_error *
 318 open_packed_ref(struct got_reference **ref, FILE *f, const char **subdirs,
 319     int nsubdirs, const char *refname, time_t mtime)
 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);
 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)
 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);
 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         } else {
 425                 FILE *f;
 426
 427                 /* Search on-disk refs before packed refs! */
 428                 for (i = 0; i < nitems(subdirs); i++) {
 429                         err = open_ref(ref, path_refs, subdirs[i], refname,
 430                             lock);
 431                         if ((err && err->code != GOT_ERR_NOT_REF) || *ref)
 432                                 goto done;
 433                 }
 434
 435                 packed_refs_path = got_repo_get_path_packed_refs(repo);
 436                 if (packed_refs_path == NULL) {
 437                         err = got_error_from_errno(
 438                             "got_repo_get_path_packed_refs");
 439                         goto done;
 440                 }
 441
 442                 if (lock) {
 443                         err = got_lockfile_lock(&lf, packed_refs_path, -1);
 444                         if (err)
 445                                 goto done;
 446                 }
 447                 f = fopen(packed_refs_path, "rbe");
 448                 if (f != NULL) {
 449                         struct stat sb;
 450                         if (fstat(fileno(f), &sb) == -1) {
 451                                 err = got_error_from_errno2("fstat",
 452                                     packed_refs_path);
 453                                 goto done;
 454                         }
 455                         err = open_packed_ref(ref, f, subdirs, nitems(subdirs),
 456                             refname, sb.st_mtime);
 457                         if (!err) {
 458                                 if (fclose(f) == EOF) {
 459                                         err = got_error_from_errno("fclose");
 460                                         got_ref_close(*ref);
 461                                         *ref = NULL;
 462                                 } else if (*ref)
 463                                         (*ref)->lf = lf;
 464                         }
 465                 }
 466         }
 467 done:
 468         if (!err && *ref == NULL)
 469                 err = got_error_not_ref(refname);
 470         if (err && lf)
 471                 got_lockfile_unlock(lf, -1);
 472         free(packed_refs_path);
 473         free(path_refs);
 474         return err;
 475 }
 476
 477 void
 478 got_ref_close(struct got_reference *ref)
 479 {
 480         if (ref->flags & GOT_REF_IS_SYMBOLIC) {
 481                 free(ref->ref.symref.name);
 482                 free(ref->ref.symref.ref);
 483         } else
 484                 free(ref->ref.ref.name);
 485         free(ref);
 486 }
 487
 488 struct got_reference *
 489 got_ref_dup(struct got_reference *ref)
 490 {
 491         struct got_reference *ret;
 492
 493         ret = calloc(1, sizeof(*ret));
 494         if (ret == NULL)
 495                 return NULL;
 496
 497         ret->flags = ref->flags;
 498         if (ref->flags & GOT_REF_IS_SYMBOLIC) {
 499                 ret->ref.symref.name = strdup(ref->ref.symref.name);
 500                 if (ret->ref.symref.name == NULL) {
 501                         free(ret);
 502                         return NULL;
 503                 }
 504                 ret->ref.symref.ref = strdup(ref->ref.symref.ref);
 505                 if (ret->ref.symref.ref == NULL) {
 506                         free(ret->ref.symref.name);
 507                         free(ret);
 508                         return NULL;
 509                 }
 510         } else {
 511                 ret->ref.ref.name = strdup(ref->ref.ref.name);
 512                 if (ret->ref.ref.name == NULL) {
 513                         free(ret);
 514                         return NULL;
 515                 }
 516                 memcpy(&ret->ref.ref.id, &ref->ref.ref.id,
 517                     sizeof(ret->ref.ref.id));
 518         }
 519
 520         return ret;
 521 }
 522
 523 const struct got_error *
 524 got_reflist_entry_dup(struct got_reflist_entry **newp,
 525     struct got_reflist_entry *re)
 526 {
 527         const struct got_error *err = NULL;
 528         struct got_reflist_entry *new;
 529
 530         *newp = NULL;
 531
 532         new = malloc(sizeof(*new));
 533         if (new == NULL)
 534                 return got_error_from_errno("malloc");
 535
 536         new->ref = got_ref_dup(re->ref);
 537         if (new->ref == NULL) {
 538                 err = got_error_from_errno("got_ref_dup");
 539                 free(new);
 540                 return err;
 541         }
 542
 543         *newp = new;
 544         return NULL;
 545 }
 546
 547 const struct got_error *
 548 got_ref_resolve_symbolic(struct got_reference **resolved,
 549     struct got_repository *repo, struct got_reference *ref)
 550 {
 551         struct got_reference *nextref;
 552         const struct got_error *err;
 553
 554         err = got_ref_open(&nextref, repo, ref->ref.symref.ref, 0);
 555         if (err)
 556                 return err;
 557
 558         if (nextref->flags & GOT_REF_IS_SYMBOLIC)
 559                 err = got_ref_resolve_symbolic(resolved, repo, nextref);
 560         else
 561                 *resolved = got_ref_dup(nextref);
 562
 563         got_ref_close(nextref);
 564         return err;
 565 }
 566
 567 static const struct got_error *
 568 ref_resolve(struct got_object_id **id, struct got_repository *repo,
 569     struct got_reference *ref, int recursion)
 570 {
 571         const struct got_error *err;
 572
 573         if (recursion <= 0)
 574                 return got_error_msg(GOT_ERR_RECURSION,
 575                     "reference recursion limit reached");
 576
 577         if (ref->flags & GOT_REF_IS_SYMBOLIC) {
 578                 struct got_reference *resolved = NULL;
 579                 err = got_ref_resolve_symbolic(&resolved, repo, ref);
 580                 if (err == NULL)
 581                         err = ref_resolve(id, repo, resolved, --recursion);
 582                 if (resolved)
 583                         got_ref_close(resolved);
 584                 return err;
 585         }
 586
 587         *id = calloc(1, sizeof(**id));
 588         if (*id == NULL)
 589                 return got_error_from_errno("calloc");
 590         memcpy(*id, &ref->ref.ref.id, sizeof(**id));
 591         return NULL;
 592 }
 593
 594 const struct got_error *
 595 got_ref_resolve(struct got_object_id **id, struct got_repository *repo,
 596     struct got_reference *ref)
 597 {
 598         return ref_resolve(id, repo, ref, GOT_REF_RECURSE_MAX);
 599 }
 600
 601 char *
 602 got_ref_to_str(struct got_reference *ref)
 603 {
 604         char *str;
 605
 606         if (ref->flags & GOT_REF_IS_SYMBOLIC)
 607                 return strdup(ref->ref.symref.ref);
 608
 609         if (got_object_id_str(&str, &ref->ref.ref.id) != NULL)
 610                 return NULL;
 611
 612         return str;
 613 }
 614
 615 const char *
 616 got_ref_get_name(struct got_reference *ref)
 617 {
 618         if (ref->flags & GOT_REF_IS_SYMBOLIC)
 619                 return ref->ref.symref.name;
 620
 621         return ref->ref.ref.name;
 622 }
 623
 624 const char *
 625 got_ref_get_symref_target(struct got_reference *ref)
 626 {
 627         if (ref->flags & GOT_REF_IS_SYMBOLIC)
 628                 return ref->ref.symref.ref;
 629
 630         return NULL;
 631 }
 632
 633 time_t
 634 got_ref_get_mtime(struct got_reference *ref)
 635 {
 636         return ref->mtime;
 637 }
 638
 639 const struct got_error *
 640 got_ref_cmp_by_name(void *arg, int *cmp, struct got_reference *re1,
 641     struct got_reference* re2)
 642 {
 643         const char *name1 = got_ref_get_name(re1);
 644         const char *name2 = got_ref_get_name(re2);
 645
 646         *cmp = got_path_cmp(name1, name2, strlen(name1), strlen(name2));
 647         return NULL;
 648 }
 649
 650 const struct got_error *
 651 got_ref_cmp_tags(void *arg, int *cmp, struct got_reference *ref1,
 652     struct got_reference *ref2)
 653 {
 654         const struct got_error *err = NULL;
 655         struct got_repository *repo = arg;
 656         struct got_object_id *id1, *id2 = NULL;
 657         struct got_tag_object *tag1 = NULL, *tag2 = NULL;
 658         struct got_commit_object *commit1 = NULL, *commit2 = NULL;
 659         time_t time1, time2;
 660
 661         *cmp = 0;
 662
 663         err = got_ref_resolve(&id1, repo, ref1);
 664         if (err)
 665                 return err;
 666         err = got_object_open_as_tag(&tag1, repo, id1);
 667         if (err) {
 668                 if (err->code != GOT_ERR_OBJ_TYPE)
 669                         goto done;
 670                 /* "lightweight" tag */
 671                 err = got_object_open_as_commit(&commit1, repo, id1);
 672                 if (err)
 673                         goto done;
 674                 time1 = got_object_commit_get_committer_time(commit1);
 675         } else
 676                 time1 = got_object_tag_get_tagger_time(tag1);
 677
 678         err = got_ref_resolve(&id2, repo, ref2);
 679         if (err)
 680                 goto done;
 681         err = got_object_open_as_tag(&tag2, repo, id2);
 682         if (err) {
 683                 if (err->code != GOT_ERR_OBJ_TYPE)
 684                         goto done;
 685                 /* "lightweight" tag */
 686                 err = got_object_open_as_commit(&commit2, repo, id2);
 687                 if (err)
 688                         goto done;
 689                 time2 = got_object_commit_get_committer_time(commit2);
 690         } else
 691                 time2 = got_object_tag_get_tagger_time(tag2);
 692
 693         /* Put latest tags first. */
 694         if (time1 < time2)
 695                 *cmp = 1;
 696         else if (time1 > time2)
 697                 *cmp = -1;
 698         else
 699                 err = got_ref_cmp_by_name(NULL, cmp, ref2, ref1);
 700 done:
 701         free(id1);
 702         free(id2);
 703         if (tag1)
 704                 got_object_tag_close(tag1);
 705         if (tag2)
 706                 got_object_tag_close(tag2);
 707         if (commit1)
 708                 got_object_commit_close(commit1);
 709         if (commit2)
 710                 got_object_commit_close(commit2);
 711         return err;
 712 }
 713
 714 static const struct got_error *
 715 get_committer_time(struct got_reference *ref, struct got_repository *repo)
 716 {
 717         const struct got_error *err = NULL;
 718         int obj_type;
 719         struct got_commit_object *commit = NULL;
 720         struct got_tag_object *tag = NULL;
 721         struct got_object_id *id = NULL;
 722
 723         err = got_ref_resolve(&id, repo, ref);
 724         if (err)
 725                 return err;
 726
 727         err = got_object_get_type(&obj_type, repo, id);
 728         if (err)
 729                 goto done;
 730
 731         switch (obj_type) {
 732         case GOT_OBJ_TYPE_COMMIT:
 733                 err = got_object_open_as_commit(&commit, repo, id);
 734                 if (err)
 735                         goto done;
 736                 ref->committer_time =
 737                     got_object_commit_get_committer_time(commit);
 738                 break;
 739         case GOT_OBJ_TYPE_TAG:
 740                 err = got_object_open_as_tag(&tag, repo, id);
 741                 if (err)
 742                         goto done;
 743                 ref->committer_time = got_object_tag_get_tagger_time(tag);
 744                 break;
 745         default:
 746                 /* best effort for other object types */
 747                 ref->committer_time = got_ref_get_mtime(ref);
 748                 break;
 749         }
 750 done:
 751         free(id);
 752         if (commit)
 753                 got_object_commit_close(commit);
 754         if (tag)
 755                 got_object_tag_close(tag);
 756         return err;
 757 }
 758
 759 const struct got_error *
 760 got_ref_cmp_by_commit_timestamp_descending(void *arg, int *cmp,
 761     struct got_reference *ref1, struct got_reference *ref2)
 762 {
 763         const struct got_error *err = NULL;
 764         struct got_repository *repo = arg;
 765
 766         *cmp = 0;
 767
 768         if (ref1->committer_time == 0) {
 769                 err = get_committer_time(ref1, repo);
 770                 if (err)
 771                         return err;
 772         }
 773         if (ref2->committer_time == 0) {
 774                 err = get_committer_time(ref2, repo);
 775                 if (err)
 776                         return err;
 777         }
 778
 779         if (ref1->committer_time < ref2->committer_time)
 780                 *cmp = 1;
 781         else if (ref2->committer_time < ref1->committer_time)
 782                 *cmp = -1;
 783         else
 784                 return got_ref_cmp_by_name(arg, cmp, ref1, ref2);
 785
 786         return err;
 787 }
 788
 789 const struct got_error *
 790 got_reflist_insert(struct got_reflist_entry **newp,
 791     struct got_reflist_head *refs, struct got_reference *ref,
 792     got_ref_cmp_cb cmp_cb, void *cmp_arg)
 793 {
 794         const struct got_error *err;
 795         struct got_reflist_entry *new, *re;
 796         int cmp;
 797
 798         *newp = NULL;
 799
 800         if (cmp_cb != got_ref_cmp_by_name && (ref->flags & GOT_REF_IS_PACKED)) {
 801                 /*
 802                  * If we are not sorting elements by name then we must still
 803                  * detect collisions between a packed ref and an on-disk ref
 804                  * using the same name. On-disk refs take precedence and are
 805                  * already present on the list before packed refs get added.
 806                  */
 807                 TAILQ_FOREACH(re, refs, entry) {
 808                         err = got_ref_cmp_by_name(NULL, &cmp, re->ref, ref);
 809                         if (err)
 810                                 return err;
 811                         if (cmp == 0)
 812                                 return NULL;
 813                 }
 814         }
 815
 816         new = malloc(sizeof(*new));
 817         if (new == NULL)
 818                 return got_error_from_errno("malloc");
 819         new->ref = ref;
 820         *newp = new;
 821
 822         /*
 823          * We must de-duplicate entries on insert because packed-refs may
 824          * contain redundant entries. On-disk refs take precedence.
 825          * This code assumes that on-disk revs are read before packed-refs.
 826          * We're iterating the list anyway, so insert elements sorted by name.
 827          *
 828          * Many callers will provide paths in a somewhat sorted order.
 829          * Iterating backwards from the tail of the list should be more
 830          * efficient than traversing through the entire list each time
 831          * an element is inserted.
 832          */
 833         re = TAILQ_LAST(refs, got_reflist_head);
 834         while (re) {
 835                 err = (*cmp_cb)(cmp_arg, &cmp, re->ref, new->ref);
 836                 if (err)
 837                         return err;
 838                 if (cmp == 0) {
 839                         /* duplicate */
 840                         free(new);
 841                         *newp = NULL;
 842                         return NULL;
 843                 } else if (cmp < 0) {
 844                         TAILQ_INSERT_AFTER(refs, re, new, entry);
 845                         return NULL;
 846                 }
 847                 re = TAILQ_PREV(re, got_reflist_head, entry);
 848         }
 849
 850         TAILQ_INSERT_HEAD(refs, new, entry);
 851         return NULL;
 852 }
 853
 854 const struct got_error *
 855 got_reflist_sort(struct got_reflist_head *refs,
 856     got_ref_cmp_cb cmp_cb, void *cmp_arg)
 857 {
 858         const struct got_error *err = NULL;
 859         struct got_reflist_entry *re, *tmp, *new;
 860         struct got_reflist_head sorted;
 861
 862         TAILQ_INIT(&sorted);
 863
 864         TAILQ_FOREACH_SAFE(re, refs, entry, tmp) {
 865                 struct got_reference *ref = re->ref;
 866                 TAILQ_REMOVE(refs, re, entry);
 867                 free(re);
 868                 err = got_reflist_insert(&new, &sorted, ref, cmp_cb, cmp_arg);
 869                 if (err || new == NULL /* duplicate */)
 870                         got_ref_close(ref);
 871                 if (err)
 872                         return err;
 873         }
 874
 875         TAILQ_CONCAT(refs, &sorted, entry);
 876         return NULL;
 877 }
 878
 879 static const struct got_error *
 880 gather_on_disk_refs(struct got_reflist_head *refs, const char *path_refs,
 881     const char *subdir, struct got_repository *repo,
 882     got_ref_cmp_cb cmp_cb, void *cmp_arg)
 883 {
 884         const struct got_error *err = NULL;
 885         DIR *d = NULL;
 886         char *path_subdir;
 887
 888         while (subdir[0] == '/')
 889                 subdir++;
 890
 891         if (asprintf(&path_subdir, "%s/%s", path_refs, subdir) == -1)
 892                 return got_error_from_errno("asprintf");
 893
 894         d = opendir(path_subdir);
 895         if (d == NULL)
 896                 goto done;
 897
 898         for (;;) {
 899                 struct dirent *dent;
 900                 struct got_reference *ref;
 901                 char *child;
 902                 int type;
 903
 904                 dent = readdir(d);
 905                 if (dent == NULL)
 906                         break;
 907
 908                 if (strcmp(dent->d_name, ".") == 0 ||
 909                     strcmp(dent->d_name, "..") == 0)
 910                         continue;
 911
 912                 err = got_path_dirent_type(&type, path_subdir, dent);
 913                 if (err)
 914                         break;
 915
 916                 switch (type) {
 917                 case DT_REG:
 918                         err = open_ref(&ref, path_refs, subdir, dent->d_name,
 919                             0);
 920                         if (err)
 921                                 goto done;
 922                         if (ref) {
 923                                 struct got_reflist_entry *new;
 924                                 err = got_reflist_insert(&new, refs, ref,
 925                                     cmp_cb, cmp_arg);
 926                                 if (err || new == NULL /* duplicate */)
 927                                         got_ref_close(ref);
 928                                 if (err)
 929                                         goto done;
 930                         }
 931                         break;
 932                 case DT_DIR:
 933                         if (asprintf(&child, "%s%s%s", subdir,
 934                             subdir[0] == '\0' ? "" : "/", dent->d_name) == -1) {
 935                                 err = got_error_from_errno("asprintf");
 936                                 break;
 937                         }
 938                         err = gather_on_disk_refs(refs, path_refs, child, repo,
 939                             cmp_cb, cmp_arg);
 940                         free(child);
 941                         break;
 942                 default:
 943                         break;
 944                 }
 945         }
 946 done:
 947         if (d)
 948                 closedir(d);
 949         free(path_subdir);
 950         return err;
 951 }
 952
 953 const struct got_error *
 954 got_ref_list(struct got_reflist_head *refs, struct got_repository *repo,
 955     const char *ref_namespace, got_ref_cmp_cb cmp_cb, void *cmp_arg)
 956 {
 957         const struct got_error *err;
 958         char *packed_refs_path = NULL, *path_refs = NULL;
 959         char *abs_namespace = NULL, *buf = NULL;
 960         const char *ondisk_ref_namespace = NULL;
 961         char *line = NULL;
 962         FILE *f = NULL;
 963         struct got_reference *ref;
 964         struct got_reflist_entry *new;
 965
 966         if (ref_namespace == NULL || ref_namespace[0] == '\0') {
 967                 path_refs = get_refs_dir_path(repo, GOT_REF_HEAD);
 968                 if (path_refs == NULL) {
 969                         err = got_error_from_errno("get_refs_dir_path");
 970                         goto done;
 971                 }
 972                 err = open_ref(&ref, path_refs, "", GOT_REF_HEAD, 0);
 973                 if (err)
 974                         goto done;
 975                 err = got_reflist_insert(&new, refs, ref, cmp_cb, cmp_arg);
 976                 if (err || new == NULL /* duplicate */)
 977                         got_ref_close(ref);
 978                 if (err && err->code != GOT_ERR_NOT_REF)
 979                         goto done;
 980         } else {
 981                 /* Try listing a single reference. */
 982                 const char *refname = ref_namespace;
 983                 path_refs = get_refs_dir_path(repo, refname);
 984                 if (path_refs == NULL) {
 985                         err = got_error_from_errno("get_refs_dir_path");
 986                         goto done;
 987                 }
 988                 err = open_ref(&ref, path_refs, "", refname, 0);
 989                 if (err) {
 990                         if (err->code != GOT_ERR_NOT_REF)
 991                                 goto done;
 992                         /* Try to look up references in a given namespace. */
 993                 } else {
 994                         err = got_reflist_insert(&new, refs, ref,
 995                             cmp_cb, cmp_arg);
 996                         if (err || new == NULL /* duplicate */)
 997                                 got_ref_close(ref);
 998                         return err;
 999                 }
1000         }
1001
1002         if (ref_namespace) {
1003                 size_t len;
1004                 /* Canonicalize the path to eliminate double-slashes if any. */
1005                 if (asprintf(&abs_namespace, "/%s", ref_namespace) == -1) {
1006                         err = got_error_from_errno("asprintf");
1007                         goto done;
1008                 }
1009                 len = strlen(abs_namespace) + 1;
1010                 buf = malloc(len);
1011                 if (buf == NULL) {
1012                         err = got_error_from_errno("malloc");
1013                         goto done;
1014                 }
1015                 err = got_canonpath(abs_namespace, buf, len);
1016                 if (err)
1017                         goto done;
1018                 ondisk_ref_namespace = buf;
1019                 while (ondisk_ref_namespace[0] == '/')
1020                         ondisk_ref_namespace++;
1021                 if (strncmp(ondisk_ref_namespace, "refs/", 5) == 0)
1022                         ondisk_ref_namespace += 5;
1023                 else if (strcmp(ondisk_ref_namespace, "refs") == 0)
1024                         ondisk_ref_namespace = "";
1025         }
1026
1027         /* Gather on-disk refs before parsing packed-refs. */
1028         free(path_refs);
1029         path_refs = get_refs_dir_path(repo, "");
1030         if (path_refs == NULL) {
1031                 err = got_error_from_errno("get_refs_dir_path");
1032                 goto done;
1033         }
1034         err = gather_on_disk_refs(refs, path_refs,
1035             ondisk_ref_namespace ? ondisk_ref_namespace : "", repo,
1036             cmp_cb, cmp_arg);
1037         if (err)
1038                 goto done;
1039
1040         /*
1041          * The packed-refs file may contain redundant entries, in which
1042          * case on-disk refs take precedence.
1043          */
1044         packed_refs_path = got_repo_get_path_packed_refs(repo);
1045         if (packed_refs_path == NULL) {
1046                 err = got_error_from_errno("got_repo_get_path_packed_refs");
1047                 goto done;
1048         }
1049
1050         f = fopen(packed_refs_path, "re");
1051         if (f) {
1052                 size_t linesize = 0;
1053                 ssize_t linelen;
1054                 struct stat sb;
1055
1056                 if (fstat(fileno(f), &sb) == -1) {
1057                         err = got_error_from_errno2("fstat", packed_refs_path);
1058                         goto done;
1059                 }
1060                 for (;;) {
1061                         linelen = getline(&line, &linesize, f);
1062                         if (linelen == -1) {
1063                                 if (feof(f))
1064                                         break;
1065                                 err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
1066                                 goto done;
1067                         }
1068                         if (linelen > 0 && line[linelen - 1] == '\n')
1069                                 line[linelen - 1] = '\0';
1070                         err = parse_packed_ref_line(&ref, NULL, line,
1071                             sb.st_mtime);
1072                         if (err)
1073                                 goto done;
1074                         if (ref) {
1075                                 if (ref_namespace) {
1076                                         const char *name;
1077                                         name = got_ref_get_name(ref);
1078                                         if (!got_path_is_child(name,
1079                                             ref_namespace,
1080                                             strlen(ref_namespace))) {
1081                                                 got_ref_close(ref);
1082                                                 continue;
1083                                         }
1084                                 }
1085                                 err = got_reflist_insert(&new, refs, ref,
1086                                     cmp_cb, cmp_arg);
1087                                 if (err || new == NULL /* duplicate */)
1088                                         got_ref_close(ref);
1089                                 if (err)
1090                                         goto done;
1091                         }
1092                 }
1093         }
1094 done:
1095         free(packed_refs_path);
1096         free(abs_namespace);
1097         free(buf);
1098         free(line);
1099         free(path_refs);
1100         if (f && fclose(f) == EOF && err == NULL)
1101                 err = got_error_from_errno("fclose");
1102         return err;
1103 }
1104
1105 void
1106 got_ref_list_free(struct got_reflist_head *refs)
1107 {
1108         struct got_reflist_entry *re;
1109
1110         while ((re = TAILQ_FIRST(refs))) {
1111                 TAILQ_REMOVE(refs, re, entry);
1112                 got_ref_close(re->ref);
1113                 free(re);
1114         }
1115 }
1116
1117 int
1118 got_ref_is_symbolic(struct got_reference *ref)
1119 {
1120         return (ref->flags & GOT_REF_IS_SYMBOLIC);
1121 }
1122
1123 const struct got_error *
1124 got_ref_change_ref(struct got_reference *ref, struct got_object_id *id)
1125 {
1126         if (ref->flags & GOT_REF_IS_SYMBOLIC)
1127                 return got_error(GOT_ERR_BAD_REF_TYPE);
1128
1129         memcpy(&ref->ref.ref.id, id, sizeof(ref->ref.ref.id));
1130         return NULL;
1131 }
1132
1133 const struct got_error *
1134 got_ref_change_symref(struct got_reference *ref, const char *refname)
1135 {
1136         char *new_name;
1137
1138         if ((ref->flags & GOT_REF_IS_SYMBOLIC) == 0)
1139                 return got_error(GOT_ERR_BAD_REF_TYPE);
1140
1141         new_name = strdup(refname);
1142         if (new_name == NULL)
1143                 return got_error_from_errno("strdup");
1144
1145         free(ref->ref.symref.ref);
1146         ref->ref.symref.ref = new_name;
1147         return NULL;
1148 }
1149
1150 const struct got_error *
1151 got_ref_change_symref_to_ref(struct got_reference *symref,
1152     struct got_object_id *id)
1153 {
1154         if ((symref->flags & GOT_REF_IS_SYMBOLIC) == 0)
1155                 return got_error(GOT_ERR_BAD_REF_TYPE);
1156
1157         symref->ref.ref.name = symref->ref.symref.name;
1158         memcpy(&symref->ref.ref.id, id, sizeof(symref->ref.ref.id));
1159         symref->flags &= ~GOT_REF_IS_SYMBOLIC;
1160         return NULL;
1161 }
1162
1163 const struct got_error *
1164 got_ref_write(struct got_reference *ref, struct got_repository *repo)
1165 {
1166         const struct got_error *err = NULL, *unlock_err = NULL;
1167         const char *name = got_ref_get_name(ref);
1168         char *path_refs = NULL, *path = NULL, *tmppath = NULL;
1169         struct got_lockfile *lf = NULL;
1170         FILE *f = NULL;
1171         size_t n;
1172         struct stat sb;
1173
1174         path_refs = get_refs_dir_path(repo, name);
1175         if (path_refs == NULL) {
1176                 err = got_error_from_errno2("get_refs_dir_path", name);
1177                 goto done;
1178         }
1179
1180         if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
1181                 err = got_error_from_errno("asprintf");
1182                 goto done;
1183         }
1184
1185         err = got_opentemp_named(&tmppath, &f, path, "");
1186         if (err) {
1187                 char *parent;
1188                 if (!(err->code == GOT_ERR_ERRNO && errno == ENOENT))
1189                         goto done;
1190                 err = got_path_dirname(&parent, path);
1191                 if (err)
1192                         goto done;
1193                 err = got_path_mkdir(parent);
1194                 free(parent);
1195                 if (err)
1196                         goto done;
1197                 err = got_opentemp_named(&tmppath, &f, path, "");
1198                 if (err)
1199                         goto done;
1200         }
1201
1202         if (ref->flags & GOT_REF_IS_SYMBOLIC) {
1203                 n = fprintf(f, "ref: %s\n", ref->ref.symref.ref);
1204                 if (n != strlen(ref->ref.symref.ref) + 6) {
1205                         err = got_ferror(f, GOT_ERR_IO);
1206                         goto done;
1207                 }
1208         } else {
1209                 char *hex;
1210                 size_t len;
1211
1212                 err = got_object_id_str(&hex, &ref->ref.ref.id);
1213                 if (err)
1214                         goto done;
1215                 len = strlen(hex);
1216                 n = fprintf(f, "%s\n", hex);
1217                 free(hex);
1218                 if (n != len + 1) {
1219                         err = got_ferror(f, GOT_ERR_IO);
1220                         goto done;
1221                 }
1222         }
1223
1224         if (ref->lf == NULL) {
1225                 err = got_lockfile_lock(&lf, path, -1);
1226                 if (err)
1227                         goto done;
1228         }
1229
1230         /* XXX: check if old content matches our expectations? */
1231
1232         if (stat(path, &sb) != 0) {
1233                 if (errno != ENOENT) {
1234                         err = got_error_from_errno2("stat", path);
1235                         goto done;
1236                 }
1237                 sb.st_mode = GOT_DEFAULT_FILE_MODE;
1238         }
1239
1240         if (fchmod(fileno(f), sb.st_mode) != 0) {
1241                 err = got_error_from_errno2("fchmod", tmppath);
1242                 goto done;
1243         }
1244
1245         if (rename(tmppath, path) != 0) {
1246                 err = got_error_from_errno3("rename", tmppath, path);
1247                 goto done;
1248         }
1249         free(tmppath);
1250         tmppath = NULL;
1251
1252         if (stat(path, &sb) == -1) {
1253                 err = got_error_from_errno2("stat", path);
1254                 goto done;
1255         }
1256         ref->mtime = sb.st_mtime;
1257 done:
1258         if (ref->lf == NULL && lf)
1259                 unlock_err = got_lockfile_unlock(lf, -1);
1260         if (f) {
1261                 if (fclose(f) == EOF && err == NULL)
1262                         err = got_error_from_errno("fclose");
1263         }
1264         free(path_refs);
1265         free(path);
1266         if (tmppath) {
1267                 if (unlink(tmppath) == -1 && err == NULL)
1268                         err = got_error_from_errno2("unlink", tmppath);
1269                 free(tmppath);
1270         }
1271         return err ? err : unlock_err;
1272 }
1273
1274 static const struct got_error *
1275 delete_packed_ref(struct got_reference *delref, struct got_repository *repo)
1276 {
1277         const struct got_error *err = NULL, *unlock_err = NULL;
1278         struct got_lockfile *lf = NULL;
1279         FILE *f = NULL, *tmpf = NULL;
1280         char *line = NULL, *packed_refs_path, *tmppath = NULL;
1281         size_t linesize = 0;
1282         struct got_reflist_head refs;
1283         int found_delref = 0;
1284
1285         /* The packed-refs file does not cotain symbolic references. */
1286         if (delref->flags & GOT_REF_IS_SYMBOLIC)
1287                 return got_error(GOT_ERR_BAD_REF_DATA);
1288
1289         TAILQ_INIT(&refs);
1290
1291         packed_refs_path = got_repo_get_path_packed_refs(repo);
1292         if (packed_refs_path == NULL)
1293                 return got_error_from_errno("got_repo_get_path_packed_refs");
1294
1295         err = got_opentemp_named(&tmppath, &tmpf, packed_refs_path, "");
1296         if (err)
1297                 goto done;
1298
1299         if (delref->lf == NULL) {
1300                 err = got_lockfile_lock(&lf, packed_refs_path, -1);
1301                 if (err)
1302                         goto done;
1303         }
1304
1305         f = fopen(packed_refs_path, "re");
1306         if (f == NULL) {
1307                 err = got_error_from_errno2("fopen", packed_refs_path);
1308                 goto done;
1309         }
1310         for (;;) {
1311                 ssize_t linelen;
1312                 struct got_reference *ref;
1313                 struct got_reflist_entry *new;
1314
1315                 linelen = getline(&line, &linesize, f);
1316                 if (linelen == -1) {
1317                         if (feof(f))
1318                                 break;
1319                         err = got_ferror(f, GOT_ERR_BAD_REF_DATA);
1320                         goto done;
1321                 }
1322                 if (linelen > 0 && line[linelen - 1] == '\n')
1323                         line[linelen - 1] = '\0';
1324                 err = parse_packed_ref_line(&ref, NULL, line, 0);
1325                 if (err)
1326                         goto done;
1327                 if (ref == NULL)
1328                         continue;
1329
1330                 if (strcmp(ref->ref.ref.name, delref->ref.ref.name) == 0 &&
1331                     got_object_id_cmp(&ref->ref.ref.id,
1332                     &delref->ref.ref.id) == 0) {
1333                         found_delref = 1;
1334                         got_ref_close(ref);
1335                         continue;
1336                 }
1337
1338                 err = got_reflist_insert(&new, &refs, ref,
1339                     got_ref_cmp_by_name, NULL);
1340                 if (err || new == NULL /* duplicate */)
1341                         got_ref_close(ref);
1342                 if (err)
1343                         goto done;
1344         }
1345
1346         if (found_delref) {
1347                 struct got_reflist_entry *re;
1348                 size_t n;
1349                 struct stat sb;
1350
1351                 n = fprintf(tmpf, "%s\n", GOT_PACKED_REFS_HEADER);
1352                 if (n != sizeof(GOT_PACKED_REFS_HEADER)) {
1353                         err = got_ferror(f, GOT_ERR_IO);
1354                         goto done;
1355                 }
1356
1357                 TAILQ_FOREACH(re, &refs, entry) {
1358                         char *hex;
1359                         size_t len;
1360
1361                         err = got_object_id_str(&hex, &re->ref->ref.ref.id);
1362                         if (err)
1363                                 goto done;
1364                         len = strlen(hex);
1365                         n = fprintf(tmpf, "%s ", hex);
1366                         free(hex);
1367                         if (n != len + 1) {
1368                                 err = got_ferror(f, GOT_ERR_IO);
1369                                 goto done;
1370                         }
1371
1372                         n = fprintf(tmpf, "%s\n", re->ref->ref.ref.name);
1373                         if (n != strlen(re->ref->ref.ref.name) + 1) {
1374                                 err = got_ferror(f, GOT_ERR_IO);
1375                                 goto done;
1376                         }
1377                 }
1378
1379                 if (fflush(tmpf) != 0) {
1380                         err = got_error_from_errno("fflush");
1381                         goto done;
1382                 }
1383
1384                 if (fstat(fileno(f), &sb) != 0) {
1385                         if (errno != ENOENT) {
1386                                 err = got_error_from_errno2("fstat",
1387                                     packed_refs_path);
1388                                 goto done;
1389                         }
1390                         sb.st_mode = GOT_DEFAULT_FILE_MODE;
1391                 }
1392
1393                 if (fchmod(fileno(tmpf), sb.st_mode) != 0) {
1394                         err = got_error_from_errno2("fchmod", tmppath);
1395                         goto done;
1396                 }
1397
1398                 if (rename(tmppath, packed_refs_path) != 0) {
1399                         err = got_error_from_errno3("rename", tmppath,
1400                             packed_refs_path);
1401                         goto done;
1402                 }
1403                 free(tmppath);
1404                 tmppath = NULL;
1405         }
1406 done:
1407         if (delref->lf == NULL && lf)
1408                 unlock_err = got_lockfile_unlock(lf, -1);
1409         if (f) {
1410                 if (fclose(f) == EOF && err == NULL)
1411                         err = got_error_from_errno("fclose");
1412         }
1413         if (tmppath && unlink(tmppath) == -1 && err == NULL)
1414                 err = got_error_from_errno2("unlink", tmppath);
1415         if (tmpf && fclose(tmpf) == EOF && err == NULL)
1416                 err = got_error_from_errno("fclose");
1417         free(tmppath);
1418         free(packed_refs_path);
1419         free(line);
1420         got_ref_list_free(&refs);
1421         return err ? err : unlock_err;
1422 }
1423
1424 static const struct got_error *
1425 delete_loose_ref(struct got_reference *ref, struct got_repository *repo)
1426 {
1427         const struct got_error *err = NULL, *unlock_err = NULL;
1428         const char *name = got_ref_get_name(ref);
1429         char *path_refs = NULL, *path = NULL;
1430         struct got_lockfile *lf = NULL;
1431
1432         path_refs = get_refs_dir_path(repo, name);
1433         if (path_refs == NULL) {
1434                 err = got_error_from_errno2("get_refs_dir_path", name);
1435                 goto done;
1436         }
1437
1438         if (asprintf(&path, "%s/%s", path_refs, name) == -1) {
1439                 err = got_error_from_errno("asprintf");
1440                 goto done;
1441         }
1442
1443         if (ref->lf == NULL) {
1444                 err = got_lockfile_lock(&lf, path, -1);
1445                 if (err)
1446                         goto done;
1447         }
1448
1449         /* XXX: check if old content matches our expectations? */
1450
1451         if (unlink(path) == -1)
1452                 err = got_error_from_errno2("unlink", path);
1453 done:
1454         if (ref->lf == NULL && lf)
1455                 unlock_err = got_lockfile_unlock(lf, -1);
1456
1457         free(path_refs);
1458         free(path);
1459         return err ? err : unlock_err;
1460 }
1461
1462 const struct got_error *
1463 got_ref_delete(struct got_reference *ref, struct got_repository *repo)
1464 {
1465         const struct got_error *err = NULL;
1466         struct got_reference *ref2;
1467
1468         if (ref->flags & GOT_REF_IS_PACKED) {
1469                 err = delete_packed_ref(ref, repo);
1470                 if (err)
1471                         return err;
1472
1473                 err = got_ref_open(&ref2, repo, got_ref_get_name(ref), 0);
1474                 if (err) {
1475                         if (err->code == GOT_ERR_NOT_REF)
1476                                 return NULL;
1477                         return err;
1478                 }
1479
1480                 err = delete_loose_ref(ref2, repo);
1481                 got_ref_close(ref2);
1482                 return err;
1483         } else {
1484                 err = delete_loose_ref(ref, repo);
1485                 if (err)
1486                         return err;
1487
1488                 err = got_ref_open(&ref2, repo, got_ref_get_name(ref), 0);
1489                 if (err) {
1490                         if (err->code == GOT_ERR_NOT_REF)
1491                                 return NULL;
1492                         return err;
1493                 }
1494
1495                 err = delete_packed_ref(ref2, repo);
1496                 got_ref_close(ref2);
1497                 return err;
1498         }
1499 }
1500
1501 const struct got_error *
1502 got_ref_unlock(struct got_reference *ref)
1503 {
1504         const struct got_error *err;
1505         err = got_lockfile_unlock(ref->lf, -1);
1506         ref->lf = NULL;
1507         return err;
1508 }
1509
1510 struct got_reflist_object_id_map {
1511         struct got_object_idset *idset;
1512 };
1513
1514 struct got_reflist_object_id_map_entry {
1515         struct got_reflist_head refs;
1516 };
1517
1518 static const struct got_error *
1519 add_object_id_map_entry(struct got_object_idset *idset,
1520     struct got_object_id *id, struct got_reflist_entry *re)
1521 {
1522         const struct got_error *err = NULL;
1523         struct got_reflist_object_id_map_entry *ent;
1524         struct got_reflist_entry *new;
1525
1526         ent = got_object_idset_get(idset, id);
1527         if (ent == NULL) {
1528                 ent = malloc(sizeof(*ent));
1529                 if (ent == NULL)
1530                         return got_error_from_errno("malloc");
1531
1532                 TAILQ_INIT(&ent->refs);
1533                 err = got_object_idset_add(idset, id, ent);
1534                 if (err) {
1535                         free(ent);
1536                         return err;
1537                 }
1538         }
1539
1540         err = got_reflist_entry_dup(&new, re);
1541         if (err)
1542                 return err;
1543
1544         TAILQ_INSERT_TAIL(&ent->refs, new, entry);
1545         return NULL;
1546 }
1547
1548 const struct got_error *
1549 got_reflist_object_id_map_create(struct got_reflist_object_id_map **map,
1550     struct got_reflist_head *refs, struct got_repository *repo)
1551 {
1552         const struct got_error *err = NULL;
1553         struct got_object_idset *idset;
1554         struct got_object_id *id = NULL;
1555         struct got_reflist_entry *re;
1556
1557         idset = got_object_idset_alloc();
1558         if (idset == NULL)
1559                 return got_error_from_errno("got_object_idset_alloc");
1560
1561         *map = malloc(sizeof(**map));
1562         if (*map == NULL) {
1563                 got_object_idset_free(idset);
1564                 return got_error_from_errno("malloc");
1565         }
1566         (*map)->idset = idset;
1567
1568         TAILQ_FOREACH(re, refs, entry) {
1569                 struct got_tag_object *tag = NULL;
1570
1571                 err = got_ref_resolve(&id, repo, re->ref);
1572                 if (err)
1573                         goto done;
1574
1575                 err = add_object_id_map_entry(idset, id, re);
1576                 if (err)
1577                         goto done;
1578
1579                 if (strstr(got_ref_get_name(re->ref), "/tags/") == NULL) {
1580                         free(id);
1581                         id = NULL;
1582                         continue;
1583                 }
1584
1585                 err = got_object_open_as_tag(&tag, repo, id);
1586                 if (err) {
1587                         if (err->code != GOT_ERR_OBJ_TYPE)
1588                                 goto done;
1589                         /* Ref points at something other than a tag. */
1590                         err = NULL;
1591                         tag = NULL;
1592                         free(id);
1593                         id = NULL;
1594                         continue;
1595                 }
1596
1597                 err = add_object_id_map_entry(idset,
1598                     got_object_tag_get_object_id(tag), re);
1599                 got_object_tag_close(tag);
1600                 if (err)
1601                         goto done;
1602
1603                 free(id);
1604                 id = NULL;
1605         }
1606 done:
1607         free(id);
1608         if (err) {
1609                 got_reflist_object_id_map_free(*map);
1610                 *map = NULL;
1611         }
1612         return err;
1613 }
1614
1615 struct got_reflist_head *
1616 got_reflist_object_id_map_lookup(struct got_reflist_object_id_map *map,
1617     struct got_object_id *id)
1618 {
1619         struct got_reflist_object_id_map_entry *ent;
1620         ent = got_object_idset_get(map->idset, id);
1621         if (ent)
1622                 return &ent->refs;
1623         return NULL;
1624 }
1625
1626 static const struct got_error *
1627 free_id_map_entry(struct got_object_id *id, void *data, void *arg)
1628 {
1629         struct got_reflist_object_id_map_entry *ent = data;
1630
1631         got_ref_list_free(&ent->refs);
1632         free(ent);
1633         return NULL;
1634 }
1635
1636 void
1637 got_reflist_object_id_map_free(struct got_reflist_object_id_map *map)
1638 {
1639         got_object_idset_for_each(map->idset, free_id_map_entry, NULL);
1640         got_object_idset_free(map->idset);
1641         free(map);
1642 }