refs.con commit checkout: tone down the "forked status" diagnostic messages (b0030db)
   1#include "cache.h"
   2#include "refs.h"
   3#include "object.h"
   4#include "tag.h"
   5#include "dir.h"
   6
   7/* ISSYMREF=01 and ISPACKED=02 are public interfaces */
   8#define REF_KNOWS_PEELED 04
   9
  10struct ref_list {
  11        struct ref_list *next;
  12        unsigned char flag; /* ISSYMREF? ISPACKED? */
  13        unsigned char sha1[20];
  14        unsigned char peeled[20];
  15        char name[FLEX_ARRAY];
  16};
  17
  18static const char *parse_ref_line(char *line, unsigned char *sha1)
  19{
  20        /*
  21         * 42: the answer to everything.
  22         *
  23         * In this case, it happens to be the answer to
  24         *  40 (length of sha1 hex representation)
  25         *  +1 (space in between hex and name)
  26         *  +1 (newline at the end of the line)
  27         */
  28        int len = strlen(line) - 42;
  29
  30        if (len <= 0)
  31                return NULL;
  32        if (get_sha1_hex(line, sha1) < 0)
  33                return NULL;
  34        if (!isspace(line[40]))
  35                return NULL;
  36        line += 41;
  37        if (isspace(*line))
  38                return NULL;
  39        if (line[len] != '\n')
  40                return NULL;
  41        line[len] = 0;
  42
  43        return line;
  44}
  45
  46static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
  47                                int flag, struct ref_list *list,
  48                                struct ref_list **new_entry)
  49{
  50        int len;
  51        struct ref_list *entry;
  52
  53        /* Allocate it and add it in.. */
  54        len = strlen(name) + 1;
  55        entry = xmalloc(sizeof(struct ref_list) + len);
  56        hashcpy(entry->sha1, sha1);
  57        hashclr(entry->peeled);
  58        memcpy(entry->name, name, len);
  59        entry->flag = flag;
  60        entry->next = list;
  61        if (new_entry)
  62                *new_entry = entry;
  63        return entry;
  64}
  65
  66/* merge sort the ref list */
  67static struct ref_list *sort_ref_list(struct ref_list *list)
  68{
  69        int psize, qsize, last_merge_count, cmp;
  70        struct ref_list *p, *q, *l, *e;
  71        struct ref_list *new_list = list;
  72        int k = 1;
  73        int merge_count = 0;
  74
  75        if (!list)
  76                return list;
  77
  78        do {
  79                last_merge_count = merge_count;
  80                merge_count = 0;
  81
  82                psize = 0;
  83
  84                p = new_list;
  85                q = new_list;
  86                new_list = NULL;
  87                l = NULL;
  88
  89                while (p) {
  90                        merge_count++;
  91
  92                        while (psize < k && q->next) {
  93                                q = q->next;
  94                                psize++;
  95                        }
  96                        qsize = k;
  97
  98                        while ((psize > 0) || (qsize > 0 && q)) {
  99                                if (qsize == 0 || !q) {
 100                                        e = p;
 101                                        p = p->next;
 102                                        psize--;
 103                                } else if (psize == 0) {
 104                                        e = q;
 105                                        q = q->next;
 106                                        qsize--;
 107                                } else {
 108                                        cmp = strcmp(q->name, p->name);
 109                                        if (cmp < 0) {
 110                                                e = q;
 111                                                q = q->next;
 112                                                qsize--;
 113                                        } else if (cmp > 0) {
 114                                                e = p;
 115                                                p = p->next;
 116                                                psize--;
 117                                        } else {
 118                                                if (hashcmp(q->sha1, p->sha1))
 119                                                        die("Duplicated ref, and SHA1s don't match: %s",
 120                                                            q->name);
 121                                                warning("Duplicated ref: %s", q->name);
 122                                                e = q;
 123                                                q = q->next;
 124                                                qsize--;
 125                                                free(e);
 126                                                e = p;
 127                                                p = p->next;
 128                                                psize--;
 129                                        }
 130                                }
 131
 132                                e->next = NULL;
 133
 134                                if (l)
 135                                        l->next = e;
 136                                if (!new_list)
 137                                        new_list = e;
 138                                l = e;
 139                        }
 140
 141                        p = q;
 142                };
 143
 144                k = k * 2;
 145        } while ((last_merge_count != merge_count) || (last_merge_count != 1));
 146
 147        return new_list;
 148}
 149
 150/*
 151 * Future: need to be in "struct repository"
 152 * when doing a full libification.
 153 */
 154static struct cached_refs {
 155        char did_loose;
 156        char did_packed;
 157        struct ref_list *loose;
 158        struct ref_list *packed;
 159} cached_refs;
 160
 161static void free_ref_list(struct ref_list *list)
 162{
 163        struct ref_list *next;
 164        for ( ; list; list = next) {
 165                next = list->next;
 166                free(list);
 167        }
 168}
 169
 170static void invalidate_cached_refs(void)
 171{
 172        struct cached_refs *ca = &cached_refs;
 173
 174        if (ca->did_loose && ca->loose)
 175                free_ref_list(ca->loose);
 176        if (ca->did_packed && ca->packed)
 177                free_ref_list(ca->packed);
 178        ca->loose = ca->packed = NULL;
 179        ca->did_loose = ca->did_packed = 0;
 180}
 181
 182static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
 183{
 184        struct ref_list *list = NULL;
 185        struct ref_list *last = NULL;
 186        char refline[PATH_MAX];
 187        int flag = REF_ISPACKED;
 188
 189        while (fgets(refline, sizeof(refline), f)) {
 190                unsigned char sha1[20];
 191                const char *name;
 192                static const char header[] = "# pack-refs with:";
 193
 194                if (!strncmp(refline, header, sizeof(header)-1)) {
 195                        const char *traits = refline + sizeof(header) - 1;
 196                        if (strstr(traits, " peeled "))
 197                                flag |= REF_KNOWS_PEELED;
 198                        /* perhaps other traits later as well */
 199                        continue;
 200                }
 201
 202                name = parse_ref_line(refline, sha1);
 203                if (name) {
 204                        list = add_ref(name, sha1, flag, list, &last);
 205                        continue;
 206                }
 207                if (last &&
 208                    refline[0] == '^' &&
 209                    strlen(refline) == 42 &&
 210                    refline[41] == '\n' &&
 211                    !get_sha1_hex(refline + 1, sha1))
 212                        hashcpy(last->peeled, sha1);
 213        }
 214        cached_refs->packed = sort_ref_list(list);
 215}
 216
 217static struct ref_list *get_packed_refs(void)
 218{
 219        if (!cached_refs.did_packed) {
 220                FILE *f = fopen(git_path("packed-refs"), "r");
 221                cached_refs.packed = NULL;
 222                if (f) {
 223                        read_packed_refs(f, &cached_refs);
 224                        fclose(f);
 225                }
 226                cached_refs.did_packed = 1;
 227        }
 228        return cached_refs.packed;
 229}
 230
 231static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
 232{
 233        DIR *dir = opendir(git_path("%s", base));
 234
 235        if (dir) {
 236                struct dirent *de;
 237                int baselen = strlen(base);
 238                char *ref = xmalloc(baselen + 257);
 239
 240                memcpy(ref, base, baselen);
 241                if (baselen && base[baselen-1] != '/')
 242                        ref[baselen++] = '/';
 243
 244                while ((de = readdir(dir)) != NULL) {
 245                        unsigned char sha1[20];
 246                        struct stat st;
 247                        int flag;
 248                        int namelen;
 249
 250                        if (de->d_name[0] == '.')
 251                                continue;
 252                        namelen = strlen(de->d_name);
 253                        if (namelen > 255)
 254                                continue;
 255                        if (has_extension(de->d_name, ".lock"))
 256                                continue;
 257                        memcpy(ref + baselen, de->d_name, namelen+1);
 258                        if (stat(git_path("%s", ref), &st) < 0)
 259                                continue;
 260                        if (S_ISDIR(st.st_mode)) {
 261                                list = get_ref_dir(ref, list);
 262                                continue;
 263                        }
 264                        if (!resolve_ref(ref, sha1, 1, &flag)) {
 265                                error("%s points nowhere!", ref);
 266                                continue;
 267                        }
 268                        list = add_ref(ref, sha1, flag, list, NULL);
 269                }
 270                free(ref);
 271                closedir(dir);
 272        }
 273        return sort_ref_list(list);
 274}
 275
 276static struct ref_list *get_loose_refs(void)
 277{
 278        if (!cached_refs.did_loose) {
 279                cached_refs.loose = get_ref_dir("refs", NULL);
 280                cached_refs.did_loose = 1;
 281        }
 282        return cached_refs.loose;
 283}
 284
 285/* We allow "recursive" symbolic refs. Only within reason, though */
 286#define MAXDEPTH 5
 287#define MAXREFLEN (1024)
 288
 289static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
 290{
 291        FILE *f;
 292        struct cached_refs refs;
 293        struct ref_list *ref;
 294        int retval;
 295
 296        strcpy(name + pathlen, "packed-refs");
 297        f = fopen(name, "r");
 298        if (!f)
 299                return -1;
 300        read_packed_refs(f, &refs);
 301        fclose(f);
 302        ref = refs.packed;
 303        retval = -1;
 304        while (ref) {
 305                if (!strcmp(ref->name, refname)) {
 306                        retval = 0;
 307                        memcpy(result, ref->sha1, 20);
 308                        break;
 309                }
 310                ref = ref->next;
 311        }
 312        free_ref_list(refs.packed);
 313        return retval;
 314}
 315
 316static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
 317{
 318        int fd, len = strlen(refname);
 319        char buffer[128], *p;
 320
 321        if (recursion > MAXDEPTH || len > MAXREFLEN)
 322                return -1;
 323        memcpy(name + pathlen, refname, len+1);
 324        fd = open(name, O_RDONLY);
 325        if (fd < 0)
 326                return resolve_gitlink_packed_ref(name, pathlen, refname, result);
 327
 328        len = read(fd, buffer, sizeof(buffer)-1);
 329        close(fd);
 330        if (len < 0)
 331                return -1;
 332        while (len && isspace(buffer[len-1]))
 333                len--;
 334        buffer[len] = 0;
 335
 336        /* Was it a detached head or an old-fashioned symlink? */
 337        if (!get_sha1_hex(buffer, result))
 338                return 0;
 339
 340        /* Symref? */
 341        if (strncmp(buffer, "ref:", 4))
 342                return -1;
 343        p = buffer + 4;
 344        while (isspace(*p))
 345                p++;
 346
 347        return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
 348}
 349
 350int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
 351{
 352        int len = strlen(path), retval;
 353        char *gitdir;
 354
 355        while (len && path[len-1] == '/')
 356                len--;
 357        if (!len)
 358                return -1;
 359        gitdir = xmalloc(len + MAXREFLEN + 8);
 360        memcpy(gitdir, path, len);
 361        memcpy(gitdir + len, "/.git/", 7);
 362
 363        retval = resolve_gitlink_ref_recursive(gitdir, len+6, refname, result, 0);
 364        free(gitdir);
 365        return retval;
 366}
 367
 368const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
 369{
 370        int depth = MAXDEPTH, len;
 371        char buffer[256];
 372        static char ref_buffer[256];
 373
 374        if (flag)
 375                *flag = 0;
 376
 377        for (;;) {
 378                const char *path = git_path("%s", ref);
 379                struct stat st;
 380                char *buf;
 381                int fd;
 382
 383                if (--depth < 0)
 384                        return NULL;
 385
 386                /* Special case: non-existing file.
 387                 * Not having the refs/heads/new-branch is OK
 388                 * if we are writing into it, so is .git/HEAD
 389                 * that points at refs/heads/master still to be
 390                 * born.  It is NOT OK if we are resolving for
 391                 * reading.
 392                 */
 393                if (lstat(path, &st) < 0) {
 394                        struct ref_list *list = get_packed_refs();
 395                        while (list) {
 396                                if (!strcmp(ref, list->name)) {
 397                                        hashcpy(sha1, list->sha1);
 398                                        if (flag)
 399                                                *flag |= REF_ISPACKED;
 400                                        return ref;
 401                                }
 402                                list = list->next;
 403                        }
 404                        if (reading || errno != ENOENT)
 405                                return NULL;
 406                        hashclr(sha1);
 407                        return ref;
 408                }
 409
 410                /* Follow "normalized" - ie "refs/.." symlinks by hand */
 411                if (S_ISLNK(st.st_mode)) {
 412                        len = readlink(path, buffer, sizeof(buffer)-1);
 413                        if (len >= 5 && !memcmp("refs/", buffer, 5)) {
 414                                buffer[len] = 0;
 415                                strcpy(ref_buffer, buffer);
 416                                ref = ref_buffer;
 417                                if (flag)
 418                                        *flag |= REF_ISSYMREF;
 419                                continue;
 420                        }
 421                }
 422
 423                /* Is it a directory? */
 424                if (S_ISDIR(st.st_mode)) {
 425                        errno = EISDIR;
 426                        return NULL;
 427                }
 428
 429                /*
 430                 * Anything else, just open it and try to use it as
 431                 * a ref
 432                 */
 433                fd = open(path, O_RDONLY);
 434                if (fd < 0)
 435                        return NULL;
 436                len = read_in_full(fd, buffer, sizeof(buffer)-1);
 437                close(fd);
 438
 439                /*
 440                 * Is it a symbolic ref?
 441                 */
 442                if (len < 4 || memcmp("ref:", buffer, 4))
 443                        break;
 444                buf = buffer + 4;
 445                len -= 4;
 446                while (len && isspace(*buf))
 447                        buf++, len--;
 448                while (len && isspace(buf[len-1]))
 449                        len--;
 450                buf[len] = 0;
 451                memcpy(ref_buffer, buf, len + 1);
 452                ref = ref_buffer;
 453                if (flag)
 454                        *flag |= REF_ISSYMREF;
 455        }
 456        if (len < 40 || get_sha1_hex(buffer, sha1))
 457                return NULL;
 458        return ref;
 459}
 460
 461int read_ref(const char *ref, unsigned char *sha1)
 462{
 463        if (resolve_ref(ref, sha1, 1, NULL))
 464                return 0;
 465        return -1;
 466}
 467
 468static int do_one_ref(const char *base, each_ref_fn fn, int trim,
 469                      void *cb_data, struct ref_list *entry)
 470{
 471        if (strncmp(base, entry->name, trim))
 472                return 0;
 473        if (is_null_sha1(entry->sha1))
 474                return 0;
 475        if (!has_sha1_file(entry->sha1)) {
 476                error("%s does not point to a valid object!", entry->name);
 477                return 0;
 478        }
 479        return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
 480}
 481
 482int peel_ref(const char *ref, unsigned char *sha1)
 483{
 484        int flag;
 485        unsigned char base[20];
 486        struct object *o;
 487
 488        if (!resolve_ref(ref, base, 1, &flag))
 489                return -1;
 490
 491        if ((flag & REF_ISPACKED)) {
 492                struct ref_list *list = get_packed_refs();
 493
 494                while (list) {
 495                        if (!strcmp(list->name, ref)) {
 496                                if (list->flag & REF_KNOWS_PEELED) {
 497                                        hashcpy(sha1, list->peeled);
 498                                        return 0;
 499                                }
 500                                /* older pack-refs did not leave peeled ones */
 501                                break;
 502                        }
 503                        list = list->next;
 504                }
 505        }
 506
 507        /* fallback - callers should not call this for unpacked refs */
 508        o = parse_object(base);
 509        if (o->type == OBJ_TAG) {
 510                o = deref_tag(o, ref, 0);
 511                if (o) {
 512                        hashcpy(sha1, o->sha1);
 513                        return 0;
 514                }
 515        }
 516        return -1;
 517}
 518
 519static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
 520                           void *cb_data)
 521{
 522        int retval;
 523        struct ref_list *packed = get_packed_refs();
 524        struct ref_list *loose = get_loose_refs();
 525
 526        while (packed && loose) {
 527                struct ref_list *entry;
 528                int cmp = strcmp(packed->name, loose->name);
 529                if (!cmp) {
 530                        packed = packed->next;
 531                        continue;
 532                }
 533                if (cmp > 0) {
 534                        entry = loose;
 535                        loose = loose->next;
 536                } else {
 537                        entry = packed;
 538                        packed = packed->next;
 539                }
 540                retval = do_one_ref(base, fn, trim, cb_data, entry);
 541                if (retval)
 542                        return retval;
 543        }
 544
 545        for (packed = packed ? packed : loose; packed; packed = packed->next) {
 546                retval = do_one_ref(base, fn, trim, cb_data, packed);
 547                if (retval)
 548                        return retval;
 549        }
 550        return 0;
 551}
 552
 553int head_ref(each_ref_fn fn, void *cb_data)
 554{
 555        unsigned char sha1[20];
 556        int flag;
 557
 558        if (resolve_ref("HEAD", sha1, 1, &flag))
 559                return fn("HEAD", sha1, flag, cb_data);
 560        return 0;
 561}
 562
 563int for_each_ref(each_ref_fn fn, void *cb_data)
 564{
 565        return do_for_each_ref("refs/", fn, 0, cb_data);
 566}
 567
 568int for_each_tag_ref(each_ref_fn fn, void *cb_data)
 569{
 570        return do_for_each_ref("refs/tags/", fn, 10, cb_data);
 571}
 572
 573int for_each_branch_ref(each_ref_fn fn, void *cb_data)
 574{
 575        return do_for_each_ref("refs/heads/", fn, 11, cb_data);
 576}
 577
 578int for_each_remote_ref(each_ref_fn fn, void *cb_data)
 579{
 580        return do_for_each_ref("refs/remotes/", fn, 13, cb_data);
 581}
 582
 583/*
 584 * Make sure "ref" is something reasonable to have under ".git/refs/";
 585 * We do not like it if:
 586 *
 587 * - any path component of it begins with ".", or
 588 * - it has double dots "..", or
 589 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
 590 * - it ends with a "/".
 591 */
 592
 593static inline int bad_ref_char(int ch)
 594{
 595        if (((unsigned) ch) <= ' ' ||
 596            ch == '~' || ch == '^' || ch == ':')
 597                return 1;
 598        /* 2.13 Pattern Matching Notation */
 599        if (ch == '?' || ch == '[') /* Unsupported */
 600                return 1;
 601        if (ch == '*') /* Supported at the end */
 602                return 2;
 603        return 0;
 604}
 605
 606int check_ref_format(const char *ref)
 607{
 608        int ch, level, bad_type;
 609        const char *cp = ref;
 610
 611        level = 0;
 612        while (1) {
 613                while ((ch = *cp++) == '/')
 614                        ; /* tolerate duplicated slashes */
 615                if (!ch)
 616                        /* should not end with slashes */
 617                        return CHECK_REF_FORMAT_ERROR;
 618
 619                /* we are at the beginning of the path component */
 620                if (ch == '.')
 621                        return CHECK_REF_FORMAT_ERROR;
 622                bad_type = bad_ref_char(ch);
 623                if (bad_type) {
 624                        return (bad_type == 2 && !*cp)
 625                                ? CHECK_REF_FORMAT_WILDCARD
 626                                : CHECK_REF_FORMAT_ERROR;
 627                }
 628
 629                /* scan the rest of the path component */
 630                while ((ch = *cp++) != 0) {
 631                        bad_type = bad_ref_char(ch);
 632                        if (bad_type) {
 633                                return (bad_type == 2 && !*cp)
 634                                        ? CHECK_REF_FORMAT_WILDCARD
 635                                        : CHECK_REF_FORMAT_ERROR;
 636                        }
 637                        if (ch == '/')
 638                                break;
 639                        if (ch == '.' && *cp == '.')
 640                                return CHECK_REF_FORMAT_ERROR;
 641                }
 642                level++;
 643                if (!ch) {
 644                        if (level < 2)
 645                                return CHECK_REF_FORMAT_ONELEVEL;
 646                        return CHECK_REF_FORMAT_OK;
 647                }
 648        }
 649}
 650
 651const char *ref_rev_parse_rules[] = {
 652        "%.*s",
 653        "refs/%.*s",
 654        "refs/tags/%.*s",
 655        "refs/heads/%.*s",
 656        "refs/remotes/%.*s",
 657        "refs/remotes/%.*s/HEAD",
 658        NULL
 659};
 660
 661const char *ref_fetch_rules[] = {
 662        "%.*s",
 663        "refs/%.*s",
 664        "refs/heads/%.*s",
 665        NULL
 666};
 667
 668int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
 669{
 670        const char **p;
 671        const int abbrev_name_len = strlen(abbrev_name);
 672
 673        for (p = rules; *p; p++) {
 674                if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
 675                        return 1;
 676                }
 677        }
 678
 679        return 0;
 680}
 681
 682static struct ref_lock *verify_lock(struct ref_lock *lock,
 683        const unsigned char *old_sha1, int mustexist)
 684{
 685        if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
 686                error("Can't verify ref %s", lock->ref_name);
 687                unlock_ref(lock);
 688                return NULL;
 689        }
 690        if (hashcmp(lock->old_sha1, old_sha1)) {
 691                error("Ref %s is at %s but expected %s", lock->ref_name,
 692                        sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
 693                unlock_ref(lock);
 694                return NULL;
 695        }
 696        return lock;
 697}
 698
 699static int remove_empty_directories(const char *file)
 700{
 701        /* we want to create a file but there is a directory there;
 702         * if that is an empty directory (or a directory that contains
 703         * only empty directories), remove them.
 704         */
 705        struct strbuf path;
 706        int result;
 707
 708        strbuf_init(&path, 20);
 709        strbuf_addstr(&path, file);
 710
 711        result = remove_dir_recursively(&path, 1);
 712
 713        strbuf_release(&path);
 714
 715        return result;
 716}
 717
 718static int is_refname_available(const char *ref, const char *oldref,
 719                                struct ref_list *list, int quiet)
 720{
 721        int namlen = strlen(ref); /* e.g. 'foo/bar' */
 722        while (list) {
 723                /* list->name could be 'foo' or 'foo/bar/baz' */
 724                if (!oldref || strcmp(oldref, list->name)) {
 725                        int len = strlen(list->name);
 726                        int cmplen = (namlen < len) ? namlen : len;
 727                        const char *lead = (namlen < len) ? list->name : ref;
 728                        if (!strncmp(ref, list->name, cmplen) &&
 729                            lead[cmplen] == '/') {
 730                                if (!quiet)
 731                                        error("'%s' exists; cannot create '%s'",
 732                                              list->name, ref);
 733                                return 0;
 734                        }
 735                }
 736                list = list->next;
 737        }
 738        return 1;
 739}
 740
 741static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
 742{
 743        char *ref_file;
 744        const char *orig_ref = ref;
 745        struct ref_lock *lock;
 746        struct stat st;
 747        int last_errno = 0;
 748        int type;
 749        int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
 750
 751        lock = xcalloc(1, sizeof(struct ref_lock));
 752        lock->lock_fd = -1;
 753
 754        ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
 755        if (!ref && errno == EISDIR) {
 756                /* we are trying to lock foo but we used to
 757                 * have foo/bar which now does not exist;
 758                 * it is normal for the empty directory 'foo'
 759                 * to remain.
 760                 */
 761                ref_file = git_path("%s", orig_ref);
 762                if (remove_empty_directories(ref_file)) {
 763                        last_errno = errno;
 764                        error("there are still refs under '%s'", orig_ref);
 765                        goto error_return;
 766                }
 767                ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
 768        }
 769        if (type_p)
 770            *type_p = type;
 771        if (!ref) {
 772                last_errno = errno;
 773                error("unable to resolve reference %s: %s",
 774                        orig_ref, strerror(errno));
 775                goto error_return;
 776        }
 777        /* When the ref did not exist and we are creating it,
 778         * make sure there is no existing ref that is packed
 779         * whose name begins with our refname, nor a ref whose
 780         * name is a proper prefix of our refname.
 781         */
 782        if (is_null_sha1(lock->old_sha1) &&
 783            !is_refname_available(ref, NULL, get_packed_refs(), 0))
 784                goto error_return;
 785
 786        lock->lk = xcalloc(1, sizeof(struct lock_file));
 787
 788        if (flags & REF_NODEREF)
 789                ref = orig_ref;
 790        lock->ref_name = xstrdup(ref);
 791        lock->orig_ref_name = xstrdup(orig_ref);
 792        ref_file = git_path("%s", ref);
 793        if (lstat(ref_file, &st) && errno == ENOENT)
 794                lock->force_write = 1;
 795        if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
 796                lock->force_write = 1;
 797
 798        if (safe_create_leading_directories(ref_file)) {
 799                last_errno = errno;
 800                error("unable to create directory for %s", ref_file);
 801                goto error_return;
 802        }
 803        lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, 1);
 804
 805        return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
 806
 807 error_return:
 808        unlock_ref(lock);
 809        errno = last_errno;
 810        return NULL;
 811}
 812
 813struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
 814{
 815        char refpath[PATH_MAX];
 816        if (check_ref_format(ref))
 817                return NULL;
 818        strcpy(refpath, mkpath("refs/%s", ref));
 819        return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
 820}
 821
 822struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
 823{
 824        switch (check_ref_format(ref)) {
 825        default:
 826                return NULL;
 827        case 0:
 828        case CHECK_REF_FORMAT_ONELEVEL:
 829                return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
 830        }
 831}
 832
 833static struct lock_file packlock;
 834
 835static int repack_without_ref(const char *refname)
 836{
 837        struct ref_list *list, *packed_ref_list;
 838        int fd;
 839        int found = 0;
 840
 841        packed_ref_list = get_packed_refs();
 842        for (list = packed_ref_list; list; list = list->next) {
 843                if (!strcmp(refname, list->name)) {
 844                        found = 1;
 845                        break;
 846                }
 847        }
 848        if (!found)
 849                return 0;
 850        fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
 851        if (fd < 0)
 852                return error("cannot delete '%s' from packed refs", refname);
 853
 854        for (list = packed_ref_list; list; list = list->next) {
 855                char line[PATH_MAX + 100];
 856                int len;
 857
 858                if (!strcmp(refname, list->name))
 859                        continue;
 860                len = snprintf(line, sizeof(line), "%s %s\n",
 861                               sha1_to_hex(list->sha1), list->name);
 862                /* this should not happen but just being defensive */
 863                if (len > sizeof(line))
 864                        die("too long a refname '%s'", list->name);
 865                write_or_die(fd, line, len);
 866        }
 867        return commit_lock_file(&packlock);
 868}
 869
 870int delete_ref(const char *refname, const unsigned char *sha1)
 871{
 872        struct ref_lock *lock;
 873        int err, i, ret = 0, flag = 0;
 874
 875        lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
 876        if (!lock)
 877                return 1;
 878        if (!(flag & REF_ISPACKED)) {
 879                /* loose */
 880                i = strlen(lock->lk->filename) - 5; /* .lock */
 881                lock->lk->filename[i] = 0;
 882                err = unlink(lock->lk->filename);
 883                if (err) {
 884                        ret = 1;
 885                        error("unlink(%s) failed: %s",
 886                              lock->lk->filename, strerror(errno));
 887                }
 888                lock->lk->filename[i] = '.';
 889        }
 890        /* removing the loose one could have resurrected an earlier
 891         * packed one.  Also, if it was not loose we need to repack
 892         * without it.
 893         */
 894        ret |= repack_without_ref(refname);
 895
 896        err = unlink(git_path("logs/%s", lock->ref_name));
 897        if (err && errno != ENOENT)
 898                fprintf(stderr, "warning: unlink(%s) failed: %s",
 899                        git_path("logs/%s", lock->ref_name), strerror(errno));
 900        invalidate_cached_refs();
 901        unlock_ref(lock);
 902        return ret;
 903}
 904
 905int rename_ref(const char *oldref, const char *newref, const char *logmsg)
 906{
 907        static const char renamed_ref[] = "RENAMED-REF";
 908        unsigned char sha1[20], orig_sha1[20];
 909        int flag = 0, logmoved = 0;
 910        struct ref_lock *lock;
 911        struct stat loginfo;
 912        int log = !lstat(git_path("logs/%s", oldref), &loginfo);
 913
 914        if (S_ISLNK(loginfo.st_mode))
 915                return error("reflog for %s is a symlink", oldref);
 916
 917        if (!resolve_ref(oldref, orig_sha1, 1, &flag))
 918                return error("refname %s not found", oldref);
 919
 920        if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
 921                return 1;
 922
 923        if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
 924                return 1;
 925
 926        lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
 927        if (!lock)
 928                return error("unable to lock %s", renamed_ref);
 929        lock->force_write = 1;
 930        if (write_ref_sha1(lock, orig_sha1, logmsg))
 931                return error("unable to save current sha1 in %s", renamed_ref);
 932
 933        if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
 934                return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
 935                        oldref, strerror(errno));
 936
 937        if (delete_ref(oldref, orig_sha1)) {
 938                error("unable to delete old %s", oldref);
 939                goto rollback;
 940        }
 941
 942        if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1)) {
 943                if (errno==EISDIR) {
 944                        if (remove_empty_directories(git_path("%s", newref))) {
 945                                error("Directory not empty: %s", newref);
 946                                goto rollback;
 947                        }
 948                } else {
 949                        error("unable to delete existing %s", newref);
 950                        goto rollback;
 951                }
 952        }
 953
 954        if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
 955                error("unable to create directory for %s", newref);
 956                goto rollback;
 957        }
 958
 959 retry:
 960        if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
 961                if (errno==EISDIR || errno==ENOTDIR) {
 962                        /*
 963                         * rename(a, b) when b is an existing
 964                         * directory ought to result in ISDIR, but
 965                         * Solaris 5.8 gives ENOTDIR.  Sheesh.
 966                         */
 967                        if (remove_empty_directories(git_path("logs/%s", newref))) {
 968                                error("Directory not empty: logs/%s", newref);
 969                                goto rollback;
 970                        }
 971                        goto retry;
 972                } else {
 973                        error("unable to move logfile tmp-renamed-log to logs/%s: %s",
 974                                newref, strerror(errno));
 975                        goto rollback;
 976                }
 977        }
 978        logmoved = log;
 979
 980        lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
 981        if (!lock) {
 982                error("unable to lock %s for update", newref);
 983                goto rollback;
 984        }
 985
 986        lock->force_write = 1;
 987        hashcpy(lock->old_sha1, orig_sha1);
 988        if (write_ref_sha1(lock, orig_sha1, logmsg)) {
 989                error("unable to write current sha1 into %s", newref);
 990                goto rollback;
 991        }
 992
 993        return 0;
 994
 995 rollback:
 996        lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
 997        if (!lock) {
 998                error("unable to lock %s for rollback", oldref);
 999                goto rollbacklog;
1000        }
1001
1002        lock->force_write = 1;
1003        flag = log_all_ref_updates;
1004        log_all_ref_updates = 0;
1005        if (write_ref_sha1(lock, orig_sha1, NULL))
1006                error("unable to write current sha1 into %s", oldref);
1007        log_all_ref_updates = flag;
1008
1009 rollbacklog:
1010        if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1011                error("unable to restore logfile %s from %s: %s",
1012                        oldref, newref, strerror(errno));
1013        if (!logmoved && log &&
1014            rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
1015                error("unable to restore logfile %s from tmp-renamed-log: %s",
1016                        oldref, strerror(errno));
1017
1018        return 1;
1019}
1020
1021static int close_ref(struct ref_lock *lock)
1022{
1023        if (close_lock_file(lock->lk))
1024                return -1;
1025        lock->lock_fd = -1;
1026        return 0;
1027}
1028
1029static int commit_ref(struct ref_lock *lock)
1030{
1031        if (commit_lock_file(lock->lk))
1032                return -1;
1033        lock->lock_fd = -1;
1034        return 0;
1035}
1036
1037void unlock_ref(struct ref_lock *lock)
1038{
1039        /* Do not free lock->lk -- atexit() still looks at them */
1040        if (lock->lk)
1041                rollback_lock_file(lock->lk);
1042        free(lock->ref_name);
1043        free(lock->orig_ref_name);
1044        free(lock);
1045}
1046
1047/*
1048 * copy the reflog message msg to buf, which has been allocated sufficiently
1049 * large, while cleaning up the whitespaces.  Especially, convert LF to space,
1050 * because reflog file is one line per entry.
1051 */
1052static int copy_msg(char *buf, const char *msg)
1053{
1054        char *cp = buf;
1055        char c;
1056        int wasspace = 1;
1057
1058        *cp++ = '\t';
1059        while ((c = *msg++)) {
1060                if (wasspace && isspace(c))
1061                        continue;
1062                wasspace = isspace(c);
1063                if (wasspace)
1064                        c = ' ';
1065                *cp++ = c;
1066        }
1067        while (buf < cp && isspace(cp[-1]))
1068                cp--;
1069        *cp++ = '\n';
1070        return cp - buf;
1071}
1072
1073static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1074                         const unsigned char *new_sha1, const char *msg)
1075{
1076        int logfd, written, oflags = O_APPEND | O_WRONLY;
1077        unsigned maxlen, len;
1078        int msglen;
1079        char *log_file, *logrec;
1080        const char *committer;
1081
1082        if (log_all_ref_updates < 0)
1083                log_all_ref_updates = !is_bare_repository();
1084
1085        log_file = git_path("logs/%s", ref_name);
1086
1087        if (log_all_ref_updates &&
1088            (!prefixcmp(ref_name, "refs/heads/") ||
1089             !prefixcmp(ref_name, "refs/remotes/") ||
1090             !strcmp(ref_name, "HEAD"))) {
1091                if (safe_create_leading_directories(log_file) < 0)
1092                        return error("unable to create directory for %s",
1093                                     log_file);
1094                oflags |= O_CREAT;
1095        }
1096
1097        logfd = open(log_file, oflags, 0666);
1098        if (logfd < 0) {
1099                if (!(oflags & O_CREAT) && errno == ENOENT)
1100                        return 0;
1101
1102                if ((oflags & O_CREAT) && errno == EISDIR) {
1103                        if (remove_empty_directories(log_file)) {
1104                                return error("There are still logs under '%s'",
1105                                             log_file);
1106                        }
1107                        logfd = open(log_file, oflags, 0666);
1108                }
1109
1110                if (logfd < 0)
1111                        return error("Unable to append to %s: %s",
1112                                     log_file, strerror(errno));
1113        }
1114
1115        adjust_shared_perm(log_file);
1116
1117        msglen = msg ? strlen(msg) : 0;
1118        committer = git_committer_info(0);
1119        maxlen = strlen(committer) + msglen + 100;
1120        logrec = xmalloc(maxlen);
1121        len = sprintf(logrec, "%s %s %s\n",
1122                      sha1_to_hex(old_sha1),
1123                      sha1_to_hex(new_sha1),
1124                      committer);
1125        if (msglen)
1126                len += copy_msg(logrec + len - 1, msg) - 1;
1127        written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1128        free(logrec);
1129        if (close(logfd) != 0 || written != len)
1130                return error("Unable to append to %s", log_file);
1131        return 0;
1132}
1133
1134static int is_branch(const char *refname)
1135{
1136        return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1137}
1138
1139int write_ref_sha1(struct ref_lock *lock,
1140        const unsigned char *sha1, const char *logmsg)
1141{
1142        static char term = '\n';
1143        struct object *o;
1144
1145        if (!lock)
1146                return -1;
1147        if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1148                unlock_ref(lock);
1149                return 0;
1150        }
1151        o = parse_object(sha1);
1152        if (!o) {
1153                error("Trying to write ref %s with nonexistant object %s",
1154                        lock->ref_name, sha1_to_hex(sha1));
1155                unlock_ref(lock);
1156                return -1;
1157        }
1158        if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1159                error("Trying to write non-commit object %s to branch %s",
1160                        sha1_to_hex(sha1), lock->ref_name);
1161                unlock_ref(lock);
1162                return -1;
1163        }
1164        if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1165            write_in_full(lock->lock_fd, &term, 1) != 1
1166                || close_ref(lock) < 0) {
1167                error("Couldn't write %s", lock->lk->filename);
1168                unlock_ref(lock);
1169                return -1;
1170        }
1171        invalidate_cached_refs();
1172        if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1173            (strcmp(lock->ref_name, lock->orig_ref_name) &&
1174             log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1175                unlock_ref(lock);
1176                return -1;
1177        }
1178        if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1179                /*
1180                 * Special hack: If a branch is updated directly and HEAD
1181                 * points to it (may happen on the remote side of a push
1182                 * for example) then logically the HEAD reflog should be
1183                 * updated too.
1184                 * A generic solution implies reverse symref information,
1185                 * but finding all symrefs pointing to the given branch
1186                 * would be rather costly for this rare event (the direct
1187                 * update of a branch) to be worth it.  So let's cheat and
1188                 * check with HEAD only which should cover 99% of all usage
1189                 * scenarios (even 100% of the default ones).
1190                 */
1191                unsigned char head_sha1[20];
1192                int head_flag;
1193                const char *head_ref;
1194                head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1195                if (head_ref && (head_flag & REF_ISSYMREF) &&
1196                    !strcmp(head_ref, lock->ref_name))
1197                        log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1198        }
1199        if (commit_ref(lock)) {
1200                error("Couldn't set %s", lock->ref_name);
1201                unlock_ref(lock);
1202                return -1;
1203        }
1204        unlock_ref(lock);
1205        return 0;
1206}
1207
1208int create_symref(const char *ref_target, const char *refs_heads_master,
1209                  const char *logmsg)
1210{
1211        const char *lockpath;
1212        char ref[1000];
1213        int fd, len, written;
1214        char *git_HEAD = xstrdup(git_path("%s", ref_target));
1215        unsigned char old_sha1[20], new_sha1[20];
1216
1217        if (logmsg && read_ref(ref_target, old_sha1))
1218                hashclr(old_sha1);
1219
1220        if (safe_create_leading_directories(git_HEAD) < 0)
1221                return error("unable to create directory for %s", git_HEAD);
1222
1223#ifndef NO_SYMLINK_HEAD
1224        if (prefer_symlink_refs) {
1225                unlink(git_HEAD);
1226                if (!symlink(refs_heads_master, git_HEAD))
1227                        goto done;
1228                fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1229        }
1230#endif
1231
1232        len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1233        if (sizeof(ref) <= len) {
1234                error("refname too long: %s", refs_heads_master);
1235                goto error_free_return;
1236        }
1237        lockpath = mkpath("%s.lock", git_HEAD);
1238        fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1239        if (fd < 0) {
1240                error("Unable to open %s for writing", lockpath);
1241                goto error_free_return;
1242        }
1243        written = write_in_full(fd, ref, len);
1244        if (close(fd) != 0 || written != len) {
1245                error("Unable to write to %s", lockpath);
1246                goto error_unlink_return;
1247        }
1248        if (rename(lockpath, git_HEAD) < 0) {
1249                error("Unable to create %s", git_HEAD);
1250                goto error_unlink_return;
1251        }
1252        if (adjust_shared_perm(git_HEAD)) {
1253                error("Unable to fix permissions on %s", lockpath);
1254        error_unlink_return:
1255                unlink(lockpath);
1256        error_free_return:
1257                free(git_HEAD);
1258                return -1;
1259        }
1260
1261#ifndef NO_SYMLINK_HEAD
1262        done:
1263#endif
1264        if (logmsg && !read_ref(refs_heads_master, new_sha1))
1265                log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1266
1267        free(git_HEAD);
1268        return 0;
1269}
1270
1271static char *ref_msg(const char *line, const char *endp)
1272{
1273        const char *ep;
1274        line += 82;
1275        ep = memchr(line, '\n', endp - line);
1276        if (!ep)
1277                ep = endp;
1278        return xmemdupz(line, ep - line);
1279}
1280
1281int read_ref_at(const char *ref, unsigned long at_time, int cnt, unsigned char *sha1, char **msg, unsigned long *cutoff_time, int *cutoff_tz, int *cutoff_cnt)
1282{
1283        const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1284        char *tz_c;
1285        int logfd, tz, reccnt = 0;
1286        struct stat st;
1287        unsigned long date;
1288        unsigned char logged_sha1[20];
1289        void *log_mapped;
1290        size_t mapsz;
1291
1292        logfile = git_path("logs/%s", ref);
1293        logfd = open(logfile, O_RDONLY, 0);
1294        if (logfd < 0)
1295                die("Unable to read log %s: %s", logfile, strerror(errno));
1296        fstat(logfd, &st);
1297        if (!st.st_size)
1298                die("Log %s is empty.", logfile);
1299        mapsz = xsize_t(st.st_size);
1300        log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1301        logdata = log_mapped;
1302        close(logfd);
1303
1304        lastrec = NULL;
1305        rec = logend = logdata + st.st_size;
1306        while (logdata < rec) {
1307                reccnt++;
1308                if (logdata < rec && *(rec-1) == '\n')
1309                        rec--;
1310                lastgt = NULL;
1311                while (logdata < rec && *(rec-1) != '\n') {
1312                        rec--;
1313                        if (*rec == '>')
1314                                lastgt = rec;
1315                }
1316                if (!lastgt)
1317                        die("Log %s is corrupt.", logfile);
1318                date = strtoul(lastgt + 1, &tz_c, 10);
1319                if (date <= at_time || cnt == 0) {
1320                        tz = strtoul(tz_c, NULL, 10);
1321                        if (msg)
1322                                *msg = ref_msg(rec, logend);
1323                        if (cutoff_time)
1324                                *cutoff_time = date;
1325                        if (cutoff_tz)
1326                                *cutoff_tz = tz;
1327                        if (cutoff_cnt)
1328                                *cutoff_cnt = reccnt - 1;
1329                        if (lastrec) {
1330                                if (get_sha1_hex(lastrec, logged_sha1))
1331                                        die("Log %s is corrupt.", logfile);
1332                                if (get_sha1_hex(rec + 41, sha1))
1333                                        die("Log %s is corrupt.", logfile);
1334                                if (hashcmp(logged_sha1, sha1)) {
1335                                        fprintf(stderr,
1336                                                "warning: Log %s has gap after %s.\n",
1337                                                logfile, show_date(date, tz, DATE_RFC2822));
1338                                }
1339                        }
1340                        else if (date == at_time) {
1341                                if (get_sha1_hex(rec + 41, sha1))
1342                                        die("Log %s is corrupt.", logfile);
1343                        }
1344                        else {
1345                                if (get_sha1_hex(rec + 41, logged_sha1))
1346                                        die("Log %s is corrupt.", logfile);
1347                                if (hashcmp(logged_sha1, sha1)) {
1348                                        fprintf(stderr,
1349                                                "warning: Log %s unexpectedly ended on %s.\n",
1350                                                logfile, show_date(date, tz, DATE_RFC2822));
1351                                }
1352                        }
1353                        munmap(log_mapped, mapsz);
1354                        return 0;
1355                }
1356                lastrec = rec;
1357                if (cnt > 0)
1358                        cnt--;
1359        }
1360
1361        rec = logdata;
1362        while (rec < logend && *rec != '>' && *rec != '\n')
1363                rec++;
1364        if (rec == logend || *rec == '\n')
1365                die("Log %s is corrupt.", logfile);
1366        date = strtoul(rec + 1, &tz_c, 10);
1367        tz = strtoul(tz_c, NULL, 10);
1368        if (get_sha1_hex(logdata, sha1))
1369                die("Log %s is corrupt.", logfile);
1370        if (msg)
1371                *msg = ref_msg(logdata, logend);
1372        munmap(log_mapped, mapsz);
1373
1374        if (cutoff_time)
1375                *cutoff_time = date;
1376        if (cutoff_tz)
1377                *cutoff_tz = tz;
1378        if (cutoff_cnt)
1379                *cutoff_cnt = reccnt;
1380        return 1;
1381}
1382
1383int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1384{
1385        const char *logfile;
1386        FILE *logfp;
1387        char buf[1024];
1388        int ret = 0;
1389
1390        logfile = git_path("logs/%s", ref);
1391        logfp = fopen(logfile, "r");
1392        if (!logfp)
1393                return -1;
1394        while (fgets(buf, sizeof(buf), logfp)) {
1395                unsigned char osha1[20], nsha1[20];
1396                char *email_end, *message;
1397                unsigned long timestamp;
1398                int len, tz;
1399
1400                /* old SP new SP name <email> SP time TAB msg LF */
1401                len = strlen(buf);
1402                if (len < 83 || buf[len-1] != '\n' ||
1403                    get_sha1_hex(buf, osha1) || buf[40] != ' ' ||
1404                    get_sha1_hex(buf + 41, nsha1) || buf[81] != ' ' ||
1405                    !(email_end = strchr(buf + 82, '>')) ||
1406                    email_end[1] != ' ' ||
1407                    !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1408                    !message || message[0] != ' ' ||
1409                    (message[1] != '+' && message[1] != '-') ||
1410                    !isdigit(message[2]) || !isdigit(message[3]) ||
1411                    !isdigit(message[4]) || !isdigit(message[5]))
1412                        continue; /* corrupt? */
1413                email_end[1] = '\0';
1414                tz = strtol(message + 1, NULL, 10);
1415                if (message[6] != '\t')
1416                        message += 6;
1417                else
1418                        message += 7;
1419                ret = fn(osha1, nsha1, buf+82, timestamp, tz, message, cb_data);
1420                if (ret)
1421                        break;
1422        }
1423        fclose(logfp);
1424        return ret;
1425}
1426
1427static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1428{
1429        DIR *dir = opendir(git_path("logs/%s", base));
1430        int retval = 0;
1431
1432        if (dir) {
1433                struct dirent *de;
1434                int baselen = strlen(base);
1435                char *log = xmalloc(baselen + 257);
1436
1437                memcpy(log, base, baselen);
1438                if (baselen && base[baselen-1] != '/')
1439                        log[baselen++] = '/';
1440
1441                while ((de = readdir(dir)) != NULL) {
1442                        struct stat st;
1443                        int namelen;
1444
1445                        if (de->d_name[0] == '.')
1446                                continue;
1447                        namelen = strlen(de->d_name);
1448                        if (namelen > 255)
1449                                continue;
1450                        if (has_extension(de->d_name, ".lock"))
1451                                continue;
1452                        memcpy(log + baselen, de->d_name, namelen+1);
1453                        if (stat(git_path("logs/%s", log), &st) < 0)
1454                                continue;
1455                        if (S_ISDIR(st.st_mode)) {
1456                                retval = do_for_each_reflog(log, fn, cb_data);
1457                        } else {
1458                                unsigned char sha1[20];
1459                                if (!resolve_ref(log, sha1, 0, NULL))
1460                                        retval = error("bad ref for %s", log);
1461                                else
1462                                        retval = fn(log, sha1, 0, cb_data);
1463                        }
1464                        if (retval)
1465                                break;
1466                }
1467                free(log);
1468                closedir(dir);
1469        }
1470        else if (*base)
1471                return errno;
1472        return retval;
1473}
1474
1475int for_each_reflog(each_ref_fn fn, void *cb_data)
1476{
1477        return do_for_each_reflog("", fn, cb_data);
1478}
1479
1480int update_ref(const char *action, const char *refname,
1481                const unsigned char *sha1, const unsigned char *oldval,
1482                int flags, enum action_on_err onerr)
1483{
1484        static struct ref_lock *lock;
1485        lock = lock_any_ref_for_update(refname, oldval, flags);
1486        if (!lock) {
1487                const char *str = "Cannot lock the ref '%s'.";
1488                switch (onerr) {
1489                case MSG_ON_ERR: error(str, refname); break;
1490                case DIE_ON_ERR: die(str, refname); break;
1491                case QUIET_ON_ERR: break;
1492                }
1493                return 1;
1494        }
1495        if (write_ref_sha1(lock, sha1, action) < 0) {
1496                const char *str = "Cannot update the ref '%s'.";
1497                switch (onerr) {
1498                case MSG_ON_ERR: error(str, refname); break;
1499                case DIE_ON_ERR: die(str, refname); break;
1500                case QUIET_ON_ERR: break;
1501                }
1502                return 1;
1503        }
1504        return 0;
1505}
1506
1507struct ref *find_ref_by_name(struct ref *list, const char *name)
1508{
1509        for ( ; list; list = list->next)
1510                if (!strcmp(list->name, name))
1511                        return list;
1512        return NULL;
1513}