refs.con commit Export rerere() and launch_editor(). (d8b7db0)
   1#include "cache.h"
   2#include "refs.h"
   3#include "object.h"
   4#include "tag.h"
   5
   6/* ISSYMREF=01 and ISPACKED=02 are public interfaces */
   7#define REF_KNOWS_PEELED 04
   8
   9struct ref_list {
  10        struct ref_list *next;
  11        unsigned char flag; /* ISSYMREF? ISPACKED? */
  12        unsigned char sha1[20];
  13        unsigned char peeled[20];
  14        char name[FLEX_ARRAY];
  15};
  16
  17static const char *parse_ref_line(char *line, unsigned char *sha1)
  18{
  19        /*
  20         * 42: the answer to everything.
  21         *
  22         * In this case, it happens to be the answer to
  23         *  40 (length of sha1 hex representation)
  24         *  +1 (space in between hex and name)
  25         *  +1 (newline at the end of the line)
  26         */
  27        int len = strlen(line) - 42;
  28
  29        if (len <= 0)
  30                return NULL;
  31        if (get_sha1_hex(line, sha1) < 0)
  32                return NULL;
  33        if (!isspace(line[40]))
  34                return NULL;
  35        line += 41;
  36        if (isspace(*line))
  37                return NULL;
  38        if (line[len] != '\n')
  39                return NULL;
  40        line[len] = 0;
  41
  42        return line;
  43}
  44
  45static struct ref_list *add_ref(const char *name, const unsigned char *sha1,
  46                                int flag, struct ref_list *list,
  47                                struct ref_list **new_entry)
  48{
  49        int len;
  50        struct ref_list *entry;
  51
  52        /* Allocate it and add it in.. */
  53        len = strlen(name) + 1;
  54        entry = xmalloc(sizeof(struct ref_list) + len);
  55        hashcpy(entry->sha1, sha1);
  56        hashclr(entry->peeled);
  57        memcpy(entry->name, name, len);
  58        entry->flag = flag;
  59        entry->next = list;
  60        if (new_entry)
  61                *new_entry = entry;
  62        return entry;
  63}
  64
  65/* merge sort the ref list */
  66static struct ref_list *sort_ref_list(struct ref_list *list)
  67{
  68        int psize, qsize, last_merge_count, cmp;
  69        struct ref_list *p, *q, *l, *e;
  70        struct ref_list *new_list = list;
  71        int k = 1;
  72        int merge_count = 0;
  73
  74        if (!list)
  75                return list;
  76
  77        do {
  78                last_merge_count = merge_count;
  79                merge_count = 0;
  80
  81                psize = 0;
  82
  83                p = new_list;
  84                q = new_list;
  85                new_list = NULL;
  86                l = NULL;
  87
  88                while (p) {
  89                        merge_count++;
  90
  91                        while (psize < k && q->next) {
  92                                q = q->next;
  93                                psize++;
  94                        }
  95                        qsize = k;
  96
  97                        while ((psize > 0) || (qsize > 0 && q)) {
  98                                if (qsize == 0 || !q) {
  99                                        e = p;
 100                                        p = p->next;
 101                                        psize--;
 102                                } else if (psize == 0) {
 103                                        e = q;
 104                                        q = q->next;
 105                                        qsize--;
 106                                } else {
 107                                        cmp = strcmp(q->name, p->name);
 108                                        if (cmp < 0) {
 109                                                e = q;
 110                                                q = q->next;
 111                                                qsize--;
 112                                        } else if (cmp > 0) {
 113                                                e = p;
 114                                                p = p->next;
 115                                                psize--;
 116                                        } else {
 117                                                if (hashcmp(q->sha1, p->sha1))
 118                                                        die("Duplicated ref, and SHA1s don't match: %s",
 119                                                            q->name);
 120                                                warning("Duplicated ref: %s", q->name);
 121                                                e = q;
 122                                                q = q->next;
 123                                                qsize--;
 124                                                free(e);
 125                                                e = p;
 126                                                p = p->next;
 127                                                psize--;
 128                                        }
 129                                }
 130
 131                                e->next = NULL;
 132
 133                                if (l)
 134                                        l->next = e;
 135                                if (!new_list)
 136                                        new_list = e;
 137                                l = e;
 138                        }
 139
 140                        p = q;
 141                };
 142
 143                k = k * 2;
 144        } while ((last_merge_count != merge_count) || (last_merge_count != 1));
 145
 146        return new_list;
 147}
 148
 149/*
 150 * Future: need to be in "struct repository"
 151 * when doing a full libification.
 152 */
 153static struct cached_refs {
 154        char did_loose;
 155        char did_packed;
 156        struct ref_list *loose;
 157        struct ref_list *packed;
 158} cached_refs;
 159
 160static void free_ref_list(struct ref_list *list)
 161{
 162        struct ref_list *next;
 163        for ( ; list; list = next) {
 164                next = list->next;
 165                free(list);
 166        }
 167}
 168
 169static void invalidate_cached_refs(void)
 170{
 171        struct cached_refs *ca = &cached_refs;
 172
 173        if (ca->did_loose && ca->loose)
 174                free_ref_list(ca->loose);
 175        if (ca->did_packed && ca->packed)
 176                free_ref_list(ca->packed);
 177        ca->loose = ca->packed = NULL;
 178        ca->did_loose = ca->did_packed = 0;
 179}
 180
 181static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
 182{
 183        struct ref_list *list = NULL;
 184        struct ref_list *last = NULL;
 185        char refline[PATH_MAX];
 186        int flag = REF_ISPACKED;
 187
 188        while (fgets(refline, sizeof(refline), f)) {
 189                unsigned char sha1[20];
 190                const char *name;
 191                static const char header[] = "# pack-refs with:";
 192
 193                if (!strncmp(refline, header, sizeof(header)-1)) {
 194                        const char *traits = refline + sizeof(header) - 1;
 195                        if (strstr(traits, " peeled "))
 196                                flag |= REF_KNOWS_PEELED;
 197                        /* perhaps other traits later as well */
 198                        continue;
 199                }
 200
 201                name = parse_ref_line(refline, sha1);
 202                if (name) {
 203                        list = add_ref(name, sha1, flag, list, &last);
 204                        continue;
 205                }
 206                if (last &&
 207                    refline[0] == '^' &&
 208                    strlen(refline) == 42 &&
 209                    refline[41] == '\n' &&
 210                    !get_sha1_hex(refline + 1, sha1))
 211                        hashcpy(last->peeled, sha1);
 212        }
 213        cached_refs->packed = sort_ref_list(list);
 214}
 215
 216static struct ref_list *get_packed_refs(void)
 217{
 218        if (!cached_refs.did_packed) {
 219                FILE *f = fopen(git_path("packed-refs"), "r");
 220                cached_refs.packed = NULL;
 221                if (f) {
 222                        read_packed_refs(f, &cached_refs);
 223                        fclose(f);
 224                }
 225                cached_refs.did_packed = 1;
 226        }
 227        return cached_refs.packed;
 228}
 229
 230static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
 231{
 232        DIR *dir = opendir(git_path("%s", base));
 233
 234        if (dir) {
 235                struct dirent *de;
 236                int baselen = strlen(base);
 237                char *ref = xmalloc(baselen + 257);
 238
 239                memcpy(ref, base, baselen);
 240                if (baselen && base[baselen-1] != '/')
 241                        ref[baselen++] = '/';
 242
 243                while ((de = readdir(dir)) != NULL) {
 244                        unsigned char sha1[20];
 245                        struct stat st;
 246                        int flag;
 247                        int namelen;
 248
 249                        if (de->d_name[0] == '.')
 250                                continue;
 251                        namelen = strlen(de->d_name);
 252                        if (namelen > 255)
 253                                continue;
 254                        if (has_extension(de->d_name, ".lock"))
 255                                continue;
 256                        memcpy(ref + baselen, de->d_name, namelen+1);
 257                        if (stat(git_path("%s", ref), &st) < 0)
 258                                continue;
 259                        if (S_ISDIR(st.st_mode)) {
 260                                list = get_ref_dir(ref, list);
 261                                continue;
 262                        }
 263                        if (!resolve_ref(ref, sha1, 1, &flag)) {
 264                                error("%s points nowhere!", ref);
 265                                continue;
 266                        }
 267                        list = add_ref(ref, sha1, flag, list, NULL);
 268                }
 269                free(ref);
 270                closedir(dir);
 271        }
 272        return sort_ref_list(list);
 273}
 274
 275static struct ref_list *get_loose_refs(void)
 276{
 277        if (!cached_refs.did_loose) {
 278                cached_refs.loose = get_ref_dir("refs", NULL);
 279                cached_refs.did_loose = 1;
 280        }
 281        return cached_refs.loose;
 282}
 283
 284/* We allow "recursive" symbolic refs. Only within reason, though */
 285#define MAXDEPTH 5
 286#define MAXREFLEN (1024)
 287
 288static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
 289{
 290        FILE *f;
 291        struct cached_refs refs;
 292        struct ref_list *ref;
 293        int retval;
 294
 295        strcpy(name + pathlen, "packed-refs");
 296        f = fopen(name, "r");
 297        if (!f)
 298                return -1;
 299        read_packed_refs(f, &refs);
 300        fclose(f);
 301        ref = refs.packed;
 302        retval = -1;
 303        while (ref) {
 304                if (!strcmp(ref->name, refname)) {
 305                        retval = 0;
 306                        memcpy(result, ref->sha1, 20);
 307                        break;
 308                }
 309                ref = ref->next;
 310        }
 311        free_ref_list(refs.packed);
 312        return retval;
 313}
 314
 315static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
 316{
 317        int fd, len = strlen(refname);
 318        char buffer[128], *p;
 319
 320        if (recursion > MAXDEPTH || len > MAXREFLEN)
 321                return -1;
 322        memcpy(name + pathlen, refname, len+1);
 323        fd = open(name, O_RDONLY);
 324        if (fd < 0)
 325                return resolve_gitlink_packed_ref(name, pathlen, refname, result);
 326
 327        len = read(fd, buffer, sizeof(buffer)-1);
 328        close(fd);
 329        if (len < 0)
 330                return -1;
 331        while (len && isspace(buffer[len-1]))
 332                len--;
 333        buffer[len] = 0;
 334
 335        /* Was it a detached head or an old-fashioned symlink? */
 336        if (!get_sha1_hex(buffer, result))
 337                return 0;
 338
 339        /* Symref? */
 340        if (strncmp(buffer, "ref:", 4))
 341                return -1;
 342        p = buffer + 4;
 343        while (isspace(*p))
 344                p++;
 345
 346        return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
 347}
 348
 349int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
 350{
 351        int len = strlen(path), retval;
 352        char *gitdir;
 353
 354        while (len && path[len-1] == '/')
 355                len--;
 356        if (!len)
 357                return -1;
 358        gitdir = xmalloc(len + MAXREFLEN + 8);
 359        memcpy(gitdir, path, len);
 360        memcpy(gitdir + len, "/.git/", 7);
 361
 362        retval = resolve_gitlink_ref_recursive(gitdir, len+6, refname, result, 0);
 363        free(gitdir);
 364        return retval;
 365}
 366
 367const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
 368{
 369        int depth = MAXDEPTH, len;
 370        char buffer[256];
 371        static char ref_buffer[256];
 372
 373        if (flag)
 374                *flag = 0;
 375
 376        for (;;) {
 377                const char *path = git_path("%s", ref);
 378                struct stat st;
 379                char *buf;
 380                int fd;
 381
 382                if (--depth < 0)
 383                        return NULL;
 384
 385                /* Special case: non-existing file.
 386                 * Not having the refs/heads/new-branch is OK
 387                 * if we are writing into it, so is .git/HEAD
 388                 * that points at refs/heads/master still to be
 389                 * born.  It is NOT OK if we are resolving for
 390                 * reading.
 391                 */
 392                if (lstat(path, &st) < 0) {
 393                        struct ref_list *list = get_packed_refs();
 394                        while (list) {
 395                                if (!strcmp(ref, list->name)) {
 396                                        hashcpy(sha1, list->sha1);
 397                                        if (flag)
 398                                                *flag |= REF_ISPACKED;
 399                                        return ref;
 400                                }
 401                                list = list->next;
 402                        }
 403                        if (reading || errno != ENOENT)
 404                                return NULL;
 405                        hashclr(sha1);
 406                        return ref;
 407                }
 408
 409                /* Follow "normalized" - ie "refs/.." symlinks by hand */
 410                if (S_ISLNK(st.st_mode)) {
 411                        len = readlink(path, buffer, sizeof(buffer)-1);
 412                        if (len >= 5 && !memcmp("refs/", buffer, 5)) {
 413                                buffer[len] = 0;
 414                                strcpy(ref_buffer, buffer);
 415                                ref = ref_buffer;
 416                                if (flag)
 417                                        *flag |= REF_ISSYMREF;
 418                                continue;
 419                        }
 420                }
 421
 422                /* Is it a directory? */
 423                if (S_ISDIR(st.st_mode)) {
 424                        errno = EISDIR;
 425                        return NULL;
 426                }
 427
 428                /*
 429                 * Anything else, just open it and try to use it as
 430                 * a ref
 431                 */
 432                fd = open(path, O_RDONLY);
 433                if (fd < 0)
 434                        return NULL;
 435                len = read_in_full(fd, buffer, sizeof(buffer)-1);
 436                close(fd);
 437
 438                /*
 439                 * Is it a symbolic ref?
 440                 */
 441                if (len < 4 || memcmp("ref:", buffer, 4))
 442                        break;
 443                buf = buffer + 4;
 444                len -= 4;
 445                while (len && isspace(*buf))
 446                        buf++, len--;
 447                while (len && isspace(buf[len-1]))
 448                        len--;
 449                buf[len] = 0;
 450                memcpy(ref_buffer, buf, len + 1);
 451                ref = ref_buffer;
 452                if (flag)
 453                        *flag |= REF_ISSYMREF;
 454        }
 455        if (len < 40 || get_sha1_hex(buffer, sha1))
 456                return NULL;
 457        return ref;
 458}
 459
 460int read_ref(const char *ref, unsigned char *sha1)
 461{
 462        if (resolve_ref(ref, sha1, 1, NULL))
 463                return 0;
 464        return -1;
 465}
 466
 467static int do_one_ref(const char *base, each_ref_fn fn, int trim,
 468                      void *cb_data, struct ref_list *entry)
 469{
 470        if (strncmp(base, entry->name, trim))
 471                return 0;
 472        if (is_null_sha1(entry->sha1))
 473                return 0;
 474        if (!has_sha1_file(entry->sha1)) {
 475                error("%s does not point to a valid object!", entry->name);
 476                return 0;
 477        }
 478        return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
 479}
 480
 481int peel_ref(const char *ref, unsigned char *sha1)
 482{
 483        int flag;
 484        unsigned char base[20];
 485        struct object *o;
 486
 487        if (!resolve_ref(ref, base, 1, &flag))
 488                return -1;
 489
 490        if ((flag & REF_ISPACKED)) {
 491                struct ref_list *list = get_packed_refs();
 492
 493                while (list) {
 494                        if (!strcmp(list->name, ref)) {
 495                                if (list->flag & REF_KNOWS_PEELED) {
 496                                        hashcpy(sha1, list->peeled);
 497                                        return 0;
 498                                }
 499                                /* older pack-refs did not leave peeled ones */
 500                                break;
 501                        }
 502                        list = list->next;
 503                }
 504        }
 505
 506        /* fallback - callers should not call this for unpacked refs */
 507        o = parse_object(base);
 508        if (o->type == OBJ_TAG) {
 509                o = deref_tag(o, ref, 0);
 510                if (o) {
 511                        hashcpy(sha1, o->sha1);
 512                        return 0;
 513                }
 514        }
 515        return -1;
 516}
 517
 518static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
 519                           void *cb_data)
 520{
 521        int retval;
 522        struct ref_list *packed = get_packed_refs();
 523        struct ref_list *loose = get_loose_refs();
 524
 525        while (packed && loose) {
 526                struct ref_list *entry;
 527                int cmp = strcmp(packed->name, loose->name);
 528                if (!cmp) {
 529                        packed = packed->next;
 530                        continue;
 531                }
 532                if (cmp > 0) {
 533                        entry = loose;
 534                        loose = loose->next;
 535                } else {
 536                        entry = packed;
 537                        packed = packed->next;
 538                }
 539                retval = do_one_ref(base, fn, trim, cb_data, entry);
 540                if (retval)
 541                        return retval;
 542        }
 543
 544        for (packed = packed ? packed : loose; packed; packed = packed->next) {
 545                retval = do_one_ref(base, fn, trim, cb_data, packed);
 546                if (retval)
 547                        return retval;
 548        }
 549        return 0;
 550}
 551
 552int head_ref(each_ref_fn fn, void *cb_data)
 553{
 554        unsigned char sha1[20];
 555        int flag;
 556
 557        if (resolve_ref("HEAD", sha1, 1, &flag))
 558                return fn("HEAD", sha1, flag, cb_data);
 559        return 0;
 560}
 561
 562int for_each_ref(each_ref_fn fn, void *cb_data)
 563{
 564        return do_for_each_ref("refs/", fn, 0, cb_data);
 565}
 566
 567int for_each_tag_ref(each_ref_fn fn, void *cb_data)
 568{
 569        return do_for_each_ref("refs/tags/", fn, 10, cb_data);
 570}
 571
 572int for_each_branch_ref(each_ref_fn fn, void *cb_data)
 573{
 574        return do_for_each_ref("refs/heads/", fn, 11, cb_data);
 575}
 576
 577int for_each_remote_ref(each_ref_fn fn, void *cb_data)
 578{
 579        return do_for_each_ref("refs/remotes/", fn, 13, cb_data);
 580}
 581
 582/* NEEDSWORK: This is only used by ssh-upload and it should go; the
 583 * caller should do resolve_ref or read_ref like everybody else.  Or
 584 * maybe everybody else should use get_ref_sha1() instead of doing
 585 * read_ref().
 586 */
 587int get_ref_sha1(const char *ref, unsigned char *sha1)
 588{
 589        if (check_ref_format(ref))
 590                return -1;
 591        return read_ref(mkpath("refs/%s", ref), sha1);
 592}
 593
 594/*
 595 * Make sure "ref" is something reasonable to have under ".git/refs/";
 596 * We do not like it if:
 597 *
 598 * - any path component of it begins with ".", or
 599 * - it has double dots "..", or
 600 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
 601 * - it ends with a "/".
 602 */
 603
 604static inline int bad_ref_char(int ch)
 605{
 606        if (((unsigned) ch) <= ' ' ||
 607            ch == '~' || ch == '^' || ch == ':')
 608                return 1;
 609        /* 2.13 Pattern Matching Notation */
 610        if (ch == '?' || ch == '[') /* Unsupported */
 611                return 1;
 612        if (ch == '*') /* Supported at the end */
 613                return 2;
 614        return 0;
 615}
 616
 617int check_ref_format(const char *ref)
 618{
 619        int ch, level, bad_type;
 620        const char *cp = ref;
 621
 622        level = 0;
 623        while (1) {
 624                while ((ch = *cp++) == '/')
 625                        ; /* tolerate duplicated slashes */
 626                if (!ch)
 627                        return -1; /* should not end with slashes */
 628
 629                /* we are at the beginning of the path component */
 630                if (ch == '.')
 631                        return -1;
 632                bad_type = bad_ref_char(ch);
 633                if (bad_type) {
 634                        return (bad_type == 2 && !*cp) ? -3 : -1;
 635                }
 636
 637                /* scan the rest of the path component */
 638                while ((ch = *cp++) != 0) {
 639                        bad_type = bad_ref_char(ch);
 640                        if (bad_type) {
 641                                return (bad_type == 2 && !*cp) ? -3 : -1;
 642                        }
 643                        if (ch == '/')
 644                                break;
 645                        if (ch == '.' && *cp == '.')
 646                                return -1;
 647                }
 648                level++;
 649                if (!ch) {
 650                        if (level < 2)
 651                                return -2; /* at least of form "heads/blah" */
 652                        return 0;
 653                }
 654        }
 655}
 656
 657static struct ref_lock *verify_lock(struct ref_lock *lock,
 658        const unsigned char *old_sha1, int mustexist)
 659{
 660        if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
 661                error("Can't verify ref %s", lock->ref_name);
 662                unlock_ref(lock);
 663                return NULL;
 664        }
 665        if (hashcmp(lock->old_sha1, old_sha1)) {
 666                error("Ref %s is at %s but expected %s", lock->ref_name,
 667                        sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
 668                unlock_ref(lock);
 669                return NULL;
 670        }
 671        return lock;
 672}
 673
 674static int remove_empty_dir_recursive(char *path, int len)
 675{
 676        DIR *dir = opendir(path);
 677        struct dirent *e;
 678        int ret = 0;
 679
 680        if (!dir)
 681                return -1;
 682        if (path[len-1] != '/')
 683                path[len++] = '/';
 684        while ((e = readdir(dir)) != NULL) {
 685                struct stat st;
 686                int namlen;
 687                if ((e->d_name[0] == '.') &&
 688                    ((e->d_name[1] == 0) ||
 689                     ((e->d_name[1] == '.') && e->d_name[2] == 0)))
 690                        continue; /* "." and ".." */
 691
 692                namlen = strlen(e->d_name);
 693                if ((len + namlen < PATH_MAX) &&
 694                    strcpy(path + len, e->d_name) &&
 695                    !lstat(path, &st) &&
 696                    S_ISDIR(st.st_mode) &&
 697                    !remove_empty_dir_recursive(path, len + namlen))
 698                        continue; /* happy */
 699
 700                /* path too long, stat fails, or non-directory still exists */
 701                ret = -1;
 702                break;
 703        }
 704        closedir(dir);
 705        if (!ret) {
 706                path[len] = 0;
 707                ret = rmdir(path);
 708        }
 709        return ret;
 710}
 711
 712static int remove_empty_directories(char *file)
 713{
 714        /* we want to create a file but there is a directory there;
 715         * if that is an empty directory (or a directory that contains
 716         * only empty directories), remove them.
 717         */
 718        char path[PATH_MAX];
 719        int len = strlen(file);
 720
 721        if (len >= PATH_MAX) /* path too long ;-) */
 722                return -1;
 723        strcpy(path, file);
 724        return remove_empty_dir_recursive(path, len);
 725}
 726
 727static int is_refname_available(const char *ref, const char *oldref,
 728                                struct ref_list *list, int quiet)
 729{
 730        int namlen = strlen(ref); /* e.g. 'foo/bar' */
 731        while (list) {
 732                /* list->name could be 'foo' or 'foo/bar/baz' */
 733                if (!oldref || strcmp(oldref, list->name)) {
 734                        int len = strlen(list->name);
 735                        int cmplen = (namlen < len) ? namlen : len;
 736                        const char *lead = (namlen < len) ? list->name : ref;
 737                        if (!strncmp(ref, list->name, cmplen) &&
 738                            lead[cmplen] == '/') {
 739                                if (!quiet)
 740                                        error("'%s' exists; cannot create '%s'",
 741                                              list->name, ref);
 742                                return 0;
 743                        }
 744                }
 745                list = list->next;
 746        }
 747        return 1;
 748}
 749
 750static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
 751{
 752        char *ref_file;
 753        const char *orig_ref = ref;
 754        struct ref_lock *lock;
 755        struct stat st;
 756        int last_errno = 0;
 757        int type;
 758        int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
 759
 760        lock = xcalloc(1, sizeof(struct ref_lock));
 761        lock->lock_fd = -1;
 762
 763        ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
 764        if (!ref && errno == EISDIR) {
 765                /* we are trying to lock foo but we used to
 766                 * have foo/bar which now does not exist;
 767                 * it is normal for the empty directory 'foo'
 768                 * to remain.
 769                 */
 770                ref_file = git_path("%s", orig_ref);
 771                if (remove_empty_directories(ref_file)) {
 772                        last_errno = errno;
 773                        error("there are still refs under '%s'", orig_ref);
 774                        goto error_return;
 775                }
 776                ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
 777        }
 778        if (type_p)
 779            *type_p = type;
 780        if (!ref) {
 781                last_errno = errno;
 782                error("unable to resolve reference %s: %s",
 783                        orig_ref, strerror(errno));
 784                goto error_return;
 785        }
 786        /* When the ref did not exist and we are creating it,
 787         * make sure there is no existing ref that is packed
 788         * whose name begins with our refname, nor a ref whose
 789         * name is a proper prefix of our refname.
 790         */
 791        if (is_null_sha1(lock->old_sha1) &&
 792            !is_refname_available(ref, NULL, get_packed_refs(), 0))
 793                goto error_return;
 794
 795        lock->lk = xcalloc(1, sizeof(struct lock_file));
 796
 797        if (flags & REF_NODEREF)
 798                ref = orig_ref;
 799        lock->ref_name = xstrdup(ref);
 800        lock->orig_ref_name = xstrdup(orig_ref);
 801        ref_file = git_path("%s", ref);
 802        if (lstat(ref_file, &st) && errno == ENOENT)
 803                lock->force_write = 1;
 804        if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
 805                lock->force_write = 1;
 806
 807        if (safe_create_leading_directories(ref_file)) {
 808                last_errno = errno;
 809                error("unable to create directory for %s", ref_file);
 810                goto error_return;
 811        }
 812        lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, 1);
 813
 814        return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
 815
 816 error_return:
 817        unlock_ref(lock);
 818        errno = last_errno;
 819        return NULL;
 820}
 821
 822struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
 823{
 824        char refpath[PATH_MAX];
 825        if (check_ref_format(ref))
 826                return NULL;
 827        strcpy(refpath, mkpath("refs/%s", ref));
 828        return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
 829}
 830
 831struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
 832{
 833        if (check_ref_format(ref) == -1)
 834                return NULL;
 835        return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
 836}
 837
 838static struct lock_file packlock;
 839
 840static int repack_without_ref(const char *refname)
 841{
 842        struct ref_list *list, *packed_ref_list;
 843        int fd;
 844        int found = 0;
 845
 846        packed_ref_list = get_packed_refs();
 847        for (list = packed_ref_list; list; list = list->next) {
 848                if (!strcmp(refname, list->name)) {
 849                        found = 1;
 850                        break;
 851                }
 852        }
 853        if (!found)
 854                return 0;
 855        fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
 856        if (fd < 0)
 857                return error("cannot delete '%s' from packed refs", refname);
 858
 859        for (list = packed_ref_list; list; list = list->next) {
 860                char line[PATH_MAX + 100];
 861                int len;
 862
 863                if (!strcmp(refname, list->name))
 864                        continue;
 865                len = snprintf(line, sizeof(line), "%s %s\n",
 866                               sha1_to_hex(list->sha1), list->name);
 867                /* this should not happen but just being defensive */
 868                if (len > sizeof(line))
 869                        die("too long a refname '%s'", list->name);
 870                write_or_die(fd, line, len);
 871        }
 872        close(fd);
 873        return commit_lock_file(&packlock);
 874}
 875
 876int delete_ref(const char *refname, const unsigned char *sha1)
 877{
 878        struct ref_lock *lock;
 879        int err, i, ret = 0, flag = 0;
 880
 881        lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
 882        if (!lock)
 883                return 1;
 884        if (!(flag & REF_ISPACKED)) {
 885                /* loose */
 886                i = strlen(lock->lk->filename) - 5; /* .lock */
 887                lock->lk->filename[i] = 0;
 888                err = unlink(lock->lk->filename);
 889                if (err) {
 890                        ret = 1;
 891                        error("unlink(%s) failed: %s",
 892                              lock->lk->filename, strerror(errno));
 893                }
 894                lock->lk->filename[i] = '.';
 895        }
 896        /* removing the loose one could have resurrected an earlier
 897         * packed one.  Also, if it was not loose we need to repack
 898         * without it.
 899         */
 900        ret |= repack_without_ref(refname);
 901
 902        err = unlink(git_path("logs/%s", lock->ref_name));
 903        if (err && errno != ENOENT)
 904                fprintf(stderr, "warning: unlink(%s) failed: %s",
 905                        git_path("logs/%s", lock->ref_name), strerror(errno));
 906        invalidate_cached_refs();
 907        unlock_ref(lock);
 908        return ret;
 909}
 910
 911int rename_ref(const char *oldref, const char *newref, const char *logmsg)
 912{
 913        static const char renamed_ref[] = "RENAMED-REF";
 914        unsigned char sha1[20], orig_sha1[20];
 915        int flag = 0, logmoved = 0;
 916        struct ref_lock *lock;
 917        struct stat loginfo;
 918        int log = !lstat(git_path("logs/%s", oldref), &loginfo);
 919
 920        if (S_ISLNK(loginfo.st_mode))
 921                return error("reflog for %s is a symlink", oldref);
 922
 923        if (!resolve_ref(oldref, orig_sha1, 1, &flag))
 924                return error("refname %s not found", oldref);
 925
 926        if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
 927                return 1;
 928
 929        if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
 930                return 1;
 931
 932        lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
 933        if (!lock)
 934                return error("unable to lock %s", renamed_ref);
 935        lock->force_write = 1;
 936        if (write_ref_sha1(lock, orig_sha1, logmsg))
 937                return error("unable to save current sha1 in %s", renamed_ref);
 938
 939        if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
 940                return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
 941                        oldref, strerror(errno));
 942
 943        if (delete_ref(oldref, orig_sha1)) {
 944                error("unable to delete old %s", oldref);
 945                goto rollback;
 946        }
 947
 948        if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1)) {
 949                if (errno==EISDIR) {
 950                        if (remove_empty_directories(git_path("%s", newref))) {
 951                                error("Directory not empty: %s", newref);
 952                                goto rollback;
 953                        }
 954                } else {
 955                        error("unable to delete existing %s", newref);
 956                        goto rollback;
 957                }
 958        }
 959
 960        if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
 961                error("unable to create directory for %s", newref);
 962                goto rollback;
 963        }
 964
 965 retry:
 966        if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
 967                if (errno==EISDIR || errno==ENOTDIR) {
 968                        /*
 969                         * rename(a, b) when b is an existing
 970                         * directory ought to result in ISDIR, but
 971                         * Solaris 5.8 gives ENOTDIR.  Sheesh.
 972                         */
 973                        if (remove_empty_directories(git_path("logs/%s", newref))) {
 974                                error("Directory not empty: logs/%s", newref);
 975                                goto rollback;
 976                        }
 977                        goto retry;
 978                } else {
 979                        error("unable to move logfile tmp-renamed-log to logs/%s: %s",
 980                                newref, strerror(errno));
 981                        goto rollback;
 982                }
 983        }
 984        logmoved = log;
 985
 986        lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
 987        if (!lock) {
 988                error("unable to lock %s for update", newref);
 989                goto rollback;
 990        }
 991
 992        lock->force_write = 1;
 993        hashcpy(lock->old_sha1, orig_sha1);
 994        if (write_ref_sha1(lock, orig_sha1, logmsg)) {
 995                error("unable to write current sha1 into %s", newref);
 996                goto rollback;
 997        }
 998
 999        return 0;
1000
1001 rollback:
1002        lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
1003        if (!lock) {
1004                error("unable to lock %s for rollback", oldref);
1005                goto rollbacklog;
1006        }
1007
1008        lock->force_write = 1;
1009        flag = log_all_ref_updates;
1010        log_all_ref_updates = 0;
1011        if (write_ref_sha1(lock, orig_sha1, NULL))
1012                error("unable to write current sha1 into %s", oldref);
1013        log_all_ref_updates = flag;
1014
1015 rollbacklog:
1016        if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1017                error("unable to restore logfile %s from %s: %s",
1018                        oldref, newref, strerror(errno));
1019        if (!logmoved && log &&
1020            rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
1021                error("unable to restore logfile %s from tmp-renamed-log: %s",
1022                        oldref, strerror(errno));
1023
1024        return 1;
1025}
1026
1027void unlock_ref(struct ref_lock *lock)
1028{
1029        if (lock->lock_fd >= 0) {
1030                close(lock->lock_fd);
1031                /* Do not free lock->lk -- atexit() still looks at them */
1032                if (lock->lk)
1033                        rollback_lock_file(lock->lk);
1034        }
1035        free(lock->ref_name);
1036        free(lock->orig_ref_name);
1037        free(lock);
1038}
1039
1040/*
1041 * copy the reflog message msg to buf, which has been allocated sufficiently
1042 * large, while cleaning up the whitespaces.  Especially, convert LF to space,
1043 * because reflog file is one line per entry.
1044 */
1045static int copy_msg(char *buf, const char *msg)
1046{
1047        char *cp = buf;
1048        char c;
1049        int wasspace = 1;
1050
1051        *cp++ = '\t';
1052        while ((c = *msg++)) {
1053                if (wasspace && isspace(c))
1054                        continue;
1055                wasspace = isspace(c);
1056                if (wasspace)
1057                        c = ' ';
1058                *cp++ = c;
1059        }
1060        while (buf < cp && isspace(cp[-1]))
1061                cp--;
1062        *cp++ = '\n';
1063        return cp - buf;
1064}
1065
1066static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1067                         const unsigned char *new_sha1, const char *msg)
1068{
1069        int logfd, written, oflags = O_APPEND | O_WRONLY;
1070        unsigned maxlen, len;
1071        int msglen;
1072        char *log_file, *logrec;
1073        const char *committer;
1074
1075        if (log_all_ref_updates < 0)
1076                log_all_ref_updates = !is_bare_repository();
1077
1078        log_file = git_path("logs/%s", ref_name);
1079
1080        if (log_all_ref_updates &&
1081            (!prefixcmp(ref_name, "refs/heads/") ||
1082             !prefixcmp(ref_name, "refs/remotes/") ||
1083             !strcmp(ref_name, "HEAD"))) {
1084                if (safe_create_leading_directories(log_file) < 0)
1085                        return error("unable to create directory for %s",
1086                                     log_file);
1087                oflags |= O_CREAT;
1088        }
1089
1090        logfd = open(log_file, oflags, 0666);
1091        if (logfd < 0) {
1092                if (!(oflags & O_CREAT) && errno == ENOENT)
1093                        return 0;
1094
1095                if ((oflags & O_CREAT) && errno == EISDIR) {
1096                        if (remove_empty_directories(log_file)) {
1097                                return error("There are still logs under '%s'",
1098                                             log_file);
1099                        }
1100                        logfd = open(log_file, oflags, 0666);
1101                }
1102
1103                if (logfd < 0)
1104                        return error("Unable to append to %s: %s",
1105                                     log_file, strerror(errno));
1106        }
1107
1108        adjust_shared_perm(log_file);
1109
1110        msglen = msg ? strlen(msg) : 0;
1111        committer = git_committer_info(-1);
1112        maxlen = strlen(committer) + msglen + 100;
1113        logrec = xmalloc(maxlen);
1114        len = sprintf(logrec, "%s %s %s\n",
1115                      sha1_to_hex(old_sha1),
1116                      sha1_to_hex(new_sha1),
1117                      committer);
1118        if (msglen)
1119                len += copy_msg(logrec + len - 1, msg) - 1;
1120        written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1121        free(logrec);
1122        if (close(logfd) != 0 || written != len)
1123                return error("Unable to append to %s", log_file);
1124        return 0;
1125}
1126
1127int write_ref_sha1(struct ref_lock *lock,
1128        const unsigned char *sha1, const char *logmsg)
1129{
1130        static char term = '\n';
1131
1132        if (!lock)
1133                return -1;
1134        if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1135                unlock_ref(lock);
1136                return 0;
1137        }
1138        if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1139            write_in_full(lock->lock_fd, &term, 1) != 1
1140                || close(lock->lock_fd) < 0) {
1141                error("Couldn't write %s", lock->lk->filename);
1142                unlock_ref(lock);
1143                return -1;
1144        }
1145        invalidate_cached_refs();
1146        if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1147            (strcmp(lock->ref_name, lock->orig_ref_name) &&
1148             log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1149                unlock_ref(lock);
1150                return -1;
1151        }
1152        if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1153                /*
1154                 * Special hack: If a branch is updated directly and HEAD
1155                 * points to it (may happen on the remote side of a push
1156                 * for example) then logically the HEAD reflog should be
1157                 * updated too.
1158                 * A generic solution implies reverse symref information,
1159                 * but finding all symrefs pointing to the given branch
1160                 * would be rather costly for this rare event (the direct
1161                 * update of a branch) to be worth it.  So let's cheat and
1162                 * check with HEAD only which should cover 99% of all usage
1163                 * scenarios (even 100% of the default ones).
1164                 */
1165                unsigned char head_sha1[20];
1166                int head_flag;
1167                const char *head_ref;
1168                head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1169                if (head_ref && (head_flag & REF_ISSYMREF) &&
1170                    !strcmp(head_ref, lock->ref_name))
1171                        log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1172        }
1173        if (commit_lock_file(lock->lk)) {
1174                error("Couldn't set %s", lock->ref_name);
1175                unlock_ref(lock);
1176                return -1;
1177        }
1178        lock->lock_fd = -1;
1179        unlock_ref(lock);
1180        return 0;
1181}
1182
1183int create_symref(const char *ref_target, const char *refs_heads_master,
1184                  const char *logmsg)
1185{
1186        const char *lockpath;
1187        char ref[1000];
1188        int fd, len, written;
1189        char *git_HEAD = xstrdup(git_path("%s", ref_target));
1190        unsigned char old_sha1[20], new_sha1[20];
1191
1192        if (logmsg && read_ref(ref_target, old_sha1))
1193                hashclr(old_sha1);
1194
1195        if (safe_create_leading_directories(git_HEAD) < 0)
1196                return error("unable to create directory for %s", git_HEAD);
1197
1198#ifndef NO_SYMLINK_HEAD
1199        if (prefer_symlink_refs) {
1200                unlink(git_HEAD);
1201                if (!symlink(refs_heads_master, git_HEAD))
1202                        goto done;
1203                fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1204        }
1205#endif
1206
1207        len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1208        if (sizeof(ref) <= len) {
1209                error("refname too long: %s", refs_heads_master);
1210                goto error_free_return;
1211        }
1212        lockpath = mkpath("%s.lock", git_HEAD);
1213        fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1214        if (fd < 0) {
1215                error("Unable to open %s for writing", lockpath);
1216                goto error_free_return;
1217        }
1218        written = write_in_full(fd, ref, len);
1219        if (close(fd) != 0 || written != len) {
1220                error("Unable to write to %s", lockpath);
1221                goto error_unlink_return;
1222        }
1223        if (rename(lockpath, git_HEAD) < 0) {
1224                error("Unable to create %s", git_HEAD);
1225                goto error_unlink_return;
1226        }
1227        if (adjust_shared_perm(git_HEAD)) {
1228                error("Unable to fix permissions on %s", lockpath);
1229        error_unlink_return:
1230                unlink(lockpath);
1231        error_free_return:
1232                free(git_HEAD);
1233                return -1;
1234        }
1235
1236#ifndef NO_SYMLINK_HEAD
1237        done:
1238#endif
1239        if (logmsg && !read_ref(refs_heads_master, new_sha1))
1240                log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1241
1242        free(git_HEAD);
1243        return 0;
1244}
1245
1246static char *ref_msg(const char *line, const char *endp)
1247{
1248        const char *ep;
1249        line += 82;
1250        ep = memchr(line, '\n', endp - line);
1251        if (!ep)
1252                ep = endp;
1253        return xmemdupz(line, ep - line);
1254}
1255
1256int 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)
1257{
1258        const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1259        char *tz_c;
1260        int logfd, tz, reccnt = 0;
1261        struct stat st;
1262        unsigned long date;
1263        unsigned char logged_sha1[20];
1264        void *log_mapped;
1265        size_t mapsz;
1266
1267        logfile = git_path("logs/%s", ref);
1268        logfd = open(logfile, O_RDONLY, 0);
1269        if (logfd < 0)
1270                die("Unable to read log %s: %s", logfile, strerror(errno));
1271        fstat(logfd, &st);
1272        if (!st.st_size)
1273                die("Log %s is empty.", logfile);
1274        mapsz = xsize_t(st.st_size);
1275        log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1276        logdata = log_mapped;
1277        close(logfd);
1278
1279        lastrec = NULL;
1280        rec = logend = logdata + st.st_size;
1281        while (logdata < rec) {
1282                reccnt++;
1283                if (logdata < rec && *(rec-1) == '\n')
1284                        rec--;
1285                lastgt = NULL;
1286                while (logdata < rec && *(rec-1) != '\n') {
1287                        rec--;
1288                        if (*rec == '>')
1289                                lastgt = rec;
1290                }
1291                if (!lastgt)
1292                        die("Log %s is corrupt.", logfile);
1293                date = strtoul(lastgt + 1, &tz_c, 10);
1294                if (date <= at_time || cnt == 0) {
1295                        tz = strtoul(tz_c, NULL, 10);
1296                        if (msg)
1297                                *msg = ref_msg(rec, logend);
1298                        if (cutoff_time)
1299                                *cutoff_time = date;
1300                        if (cutoff_tz)
1301                                *cutoff_tz = tz;
1302                        if (cutoff_cnt)
1303                                *cutoff_cnt = reccnt - 1;
1304                        if (lastrec) {
1305                                if (get_sha1_hex(lastrec, logged_sha1))
1306                                        die("Log %s is corrupt.", logfile);
1307                                if (get_sha1_hex(rec + 41, sha1))
1308                                        die("Log %s is corrupt.", logfile);
1309                                if (hashcmp(logged_sha1, sha1)) {
1310                                        fprintf(stderr,
1311                                                "warning: Log %s has gap after %s.\n",
1312                                                logfile, show_date(date, tz, DATE_RFC2822));
1313                                }
1314                        }
1315                        else if (date == at_time) {
1316                                if (get_sha1_hex(rec + 41, sha1))
1317                                        die("Log %s is corrupt.", logfile);
1318                        }
1319                        else {
1320                                if (get_sha1_hex(rec + 41, logged_sha1))
1321                                        die("Log %s is corrupt.", logfile);
1322                                if (hashcmp(logged_sha1, sha1)) {
1323                                        fprintf(stderr,
1324                                                "warning: Log %s unexpectedly ended on %s.\n",
1325                                                logfile, show_date(date, tz, DATE_RFC2822));
1326                                }
1327                        }
1328                        munmap(log_mapped, mapsz);
1329                        return 0;
1330                }
1331                lastrec = rec;
1332                if (cnt > 0)
1333                        cnt--;
1334        }
1335
1336        rec = logdata;
1337        while (rec < logend && *rec != '>' && *rec != '\n')
1338                rec++;
1339        if (rec == logend || *rec == '\n')
1340                die("Log %s is corrupt.", logfile);
1341        date = strtoul(rec + 1, &tz_c, 10);
1342        tz = strtoul(tz_c, NULL, 10);
1343        if (get_sha1_hex(logdata, sha1))
1344                die("Log %s is corrupt.", logfile);
1345        if (msg)
1346                *msg = ref_msg(logdata, logend);
1347        munmap(log_mapped, mapsz);
1348
1349        if (cutoff_time)
1350                *cutoff_time = date;
1351        if (cutoff_tz)
1352                *cutoff_tz = tz;
1353        if (cutoff_cnt)
1354                *cutoff_cnt = reccnt;
1355        return 1;
1356}
1357
1358int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1359{
1360        const char *logfile;
1361        FILE *logfp;
1362        char buf[1024];
1363        int ret = 0;
1364
1365        logfile = git_path("logs/%s", ref);
1366        logfp = fopen(logfile, "r");
1367        if (!logfp)
1368                return -1;
1369        while (fgets(buf, sizeof(buf), logfp)) {
1370                unsigned char osha1[20], nsha1[20];
1371                char *email_end, *message;
1372                unsigned long timestamp;
1373                int len, tz;
1374
1375                /* old SP new SP name <email> SP time TAB msg LF */
1376                len = strlen(buf);
1377                if (len < 83 || buf[len-1] != '\n' ||
1378                    get_sha1_hex(buf, osha1) || buf[40] != ' ' ||
1379                    get_sha1_hex(buf + 41, nsha1) || buf[81] != ' ' ||
1380                    !(email_end = strchr(buf + 82, '>')) ||
1381                    email_end[1] != ' ' ||
1382                    !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1383                    !message || message[0] != ' ' ||
1384                    (message[1] != '+' && message[1] != '-') ||
1385                    !isdigit(message[2]) || !isdigit(message[3]) ||
1386                    !isdigit(message[4]) || !isdigit(message[5]))
1387                        continue; /* corrupt? */
1388                email_end[1] = '\0';
1389                tz = strtol(message + 1, NULL, 10);
1390                if (message[6] != '\t')
1391                        message += 6;
1392                else
1393                        message += 7;
1394                ret = fn(osha1, nsha1, buf+82, timestamp, tz, message, cb_data);
1395                if (ret)
1396                        break;
1397        }
1398        fclose(logfp);
1399        return ret;
1400}
1401
1402static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1403{
1404        DIR *dir = opendir(git_path("logs/%s", base));
1405        int retval = 0;
1406
1407        if (dir) {
1408                struct dirent *de;
1409                int baselen = strlen(base);
1410                char *log = xmalloc(baselen + 257);
1411
1412                memcpy(log, base, baselen);
1413                if (baselen && base[baselen-1] != '/')
1414                        log[baselen++] = '/';
1415
1416                while ((de = readdir(dir)) != NULL) {
1417                        struct stat st;
1418                        int namelen;
1419
1420                        if (de->d_name[0] == '.')
1421                                continue;
1422                        namelen = strlen(de->d_name);
1423                        if (namelen > 255)
1424                                continue;
1425                        if (has_extension(de->d_name, ".lock"))
1426                                continue;
1427                        memcpy(log + baselen, de->d_name, namelen+1);
1428                        if (stat(git_path("logs/%s", log), &st) < 0)
1429                                continue;
1430                        if (S_ISDIR(st.st_mode)) {
1431                                retval = do_for_each_reflog(log, fn, cb_data);
1432                        } else {
1433                                unsigned char sha1[20];
1434                                if (!resolve_ref(log, sha1, 0, NULL))
1435                                        retval = error("bad ref for %s", log);
1436                                else
1437                                        retval = fn(log, sha1, 0, cb_data);
1438                        }
1439                        if (retval)
1440                                break;
1441                }
1442                free(log);
1443                closedir(dir);
1444        }
1445        else if (*base)
1446                return errno;
1447        return retval;
1448}
1449
1450int for_each_reflog(each_ref_fn fn, void *cb_data)
1451{
1452        return do_for_each_reflog("", fn, cb_data);
1453}
1454
1455int update_ref(const char *action, const char *refname,
1456                const unsigned char *sha1, const unsigned char *oldval,
1457                int flags, enum action_on_err onerr)
1458{
1459        static struct ref_lock *lock;
1460        lock = lock_any_ref_for_update(refname, oldval, flags);
1461        if (!lock) {
1462                const char *str = "Cannot lock the ref '%s'.";
1463                switch (onerr) {
1464                case MSG_ON_ERR: error(str, refname); break;
1465                case DIE_ON_ERR: die(str, refname); break;
1466                case QUIET_ON_ERR: break;
1467                }
1468                return 1;
1469        }
1470        if (write_ref_sha1(lock, sha1, action) < 0) {
1471                const char *str = "Cannot update the ref '%s'.";
1472                switch (onerr) {
1473                case MSG_ON_ERR: error(str, refname); break;
1474                case DIE_ON_ERR: die(str, refname); break;
1475                case QUIET_ON_ERR: break;
1476                }
1477                return 1;
1478        }
1479        return 0;
1480}