refs.con commit git-shell: Add 'git-upload-archive' to allowed commands. (79f72b9)
   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;
 160static struct ref_list *current_ref;
 161
 162static struct ref_list *extra_refs;
 163
 164static void free_ref_list(struct ref_list *list)
 165{
 166        struct ref_list *next;
 167        for ( ; list; list = next) {
 168                next = list->next;
 169                free(list);
 170        }
 171}
 172
 173static void invalidate_cached_refs(void)
 174{
 175        struct cached_refs *ca = &cached_refs;
 176
 177        if (ca->did_loose && ca->loose)
 178                free_ref_list(ca->loose);
 179        if (ca->did_packed && ca->packed)
 180                free_ref_list(ca->packed);
 181        ca->loose = ca->packed = NULL;
 182        ca->did_loose = ca->did_packed = 0;
 183}
 184
 185static void read_packed_refs(FILE *f, struct cached_refs *cached_refs)
 186{
 187        struct ref_list *list = NULL;
 188        struct ref_list *last = NULL;
 189        char refline[PATH_MAX];
 190        int flag = REF_ISPACKED;
 191
 192        while (fgets(refline, sizeof(refline), f)) {
 193                unsigned char sha1[20];
 194                const char *name;
 195                static const char header[] = "# pack-refs with:";
 196
 197                if (!strncmp(refline, header, sizeof(header)-1)) {
 198                        const char *traits = refline + sizeof(header) - 1;
 199                        if (strstr(traits, " peeled "))
 200                                flag |= REF_KNOWS_PEELED;
 201                        /* perhaps other traits later as well */
 202                        continue;
 203                }
 204
 205                name = parse_ref_line(refline, sha1);
 206                if (name) {
 207                        list = add_ref(name, sha1, flag, list, &last);
 208                        continue;
 209                }
 210                if (last &&
 211                    refline[0] == '^' &&
 212                    strlen(refline) == 42 &&
 213                    refline[41] == '\n' &&
 214                    !get_sha1_hex(refline + 1, sha1))
 215                        hashcpy(last->peeled, sha1);
 216        }
 217        cached_refs->packed = sort_ref_list(list);
 218}
 219
 220void add_extra_ref(const char *name, const unsigned char *sha1, int flag)
 221{
 222        extra_refs = add_ref(name, sha1, flag, extra_refs, NULL);
 223}
 224
 225void clear_extra_refs(void)
 226{
 227        free_ref_list(extra_refs);
 228        extra_refs = NULL;
 229}
 230
 231static struct ref_list *get_packed_refs(void)
 232{
 233        if (!cached_refs.did_packed) {
 234                FILE *f = fopen(git_path("packed-refs"), "r");
 235                cached_refs.packed = NULL;
 236                if (f) {
 237                        read_packed_refs(f, &cached_refs);
 238                        fclose(f);
 239                }
 240                cached_refs.did_packed = 1;
 241        }
 242        return cached_refs.packed;
 243}
 244
 245static struct ref_list *get_ref_dir(const char *base, struct ref_list *list)
 246{
 247        DIR *dir = opendir(git_path("%s", base));
 248
 249        if (dir) {
 250                struct dirent *de;
 251                int baselen = strlen(base);
 252                char *ref = xmalloc(baselen + 257);
 253
 254                memcpy(ref, base, baselen);
 255                if (baselen && base[baselen-1] != '/')
 256                        ref[baselen++] = '/';
 257
 258                while ((de = readdir(dir)) != NULL) {
 259                        unsigned char sha1[20];
 260                        struct stat st;
 261                        int flag;
 262                        int namelen;
 263
 264                        if (de->d_name[0] == '.')
 265                                continue;
 266                        namelen = strlen(de->d_name);
 267                        if (namelen > 255)
 268                                continue;
 269                        if (has_extension(de->d_name, ".lock"))
 270                                continue;
 271                        memcpy(ref + baselen, de->d_name, namelen+1);
 272                        if (stat(git_path("%s", ref), &st) < 0)
 273                                continue;
 274                        if (S_ISDIR(st.st_mode)) {
 275                                list = get_ref_dir(ref, list);
 276                                continue;
 277                        }
 278                        if (!resolve_ref(ref, sha1, 1, &flag))
 279                                hashclr(sha1);
 280                        list = add_ref(ref, sha1, flag, list, NULL);
 281                }
 282                free(ref);
 283                closedir(dir);
 284        }
 285        return sort_ref_list(list);
 286}
 287
 288struct warn_if_dangling_data {
 289        const char *refname;
 290        const char *msg_fmt;
 291};
 292
 293static int warn_if_dangling_symref(const char *refname, const unsigned char *sha1,
 294                                   int flags, void *cb_data)
 295{
 296        struct warn_if_dangling_data *d = cb_data;
 297        const char *resolves_to;
 298        unsigned char junk[20];
 299
 300        if (!(flags & REF_ISSYMREF))
 301                return 0;
 302
 303        resolves_to = resolve_ref(refname, junk, 0, NULL);
 304        if (!resolves_to || strcmp(resolves_to, d->refname))
 305                return 0;
 306
 307        printf(d->msg_fmt, refname);
 308        return 0;
 309}
 310
 311void warn_dangling_symref(const char *msg_fmt, const char *refname)
 312{
 313        struct warn_if_dangling_data data = { refname, msg_fmt };
 314        for_each_rawref(warn_if_dangling_symref, &data);
 315}
 316
 317static struct ref_list *get_loose_refs(void)
 318{
 319        if (!cached_refs.did_loose) {
 320                cached_refs.loose = get_ref_dir("refs", NULL);
 321                cached_refs.did_loose = 1;
 322        }
 323        return cached_refs.loose;
 324}
 325
 326/* We allow "recursive" symbolic refs. Only within reason, though */
 327#define MAXDEPTH 5
 328#define MAXREFLEN (1024)
 329
 330static int resolve_gitlink_packed_ref(char *name, int pathlen, const char *refname, unsigned char *result)
 331{
 332        FILE *f;
 333        struct cached_refs refs;
 334        struct ref_list *ref;
 335        int retval;
 336
 337        strcpy(name + pathlen, "packed-refs");
 338        f = fopen(name, "r");
 339        if (!f)
 340                return -1;
 341        read_packed_refs(f, &refs);
 342        fclose(f);
 343        ref = refs.packed;
 344        retval = -1;
 345        while (ref) {
 346                if (!strcmp(ref->name, refname)) {
 347                        retval = 0;
 348                        memcpy(result, ref->sha1, 20);
 349                        break;
 350                }
 351                ref = ref->next;
 352        }
 353        free_ref_list(refs.packed);
 354        return retval;
 355}
 356
 357static int resolve_gitlink_ref_recursive(char *name, int pathlen, const char *refname, unsigned char *result, int recursion)
 358{
 359        int fd, len = strlen(refname);
 360        char buffer[128], *p;
 361
 362        if (recursion > MAXDEPTH || len > MAXREFLEN)
 363                return -1;
 364        memcpy(name + pathlen, refname, len+1);
 365        fd = open(name, O_RDONLY);
 366        if (fd < 0)
 367                return resolve_gitlink_packed_ref(name, pathlen, refname, result);
 368
 369        len = read(fd, buffer, sizeof(buffer)-1);
 370        close(fd);
 371        if (len < 0)
 372                return -1;
 373        while (len && isspace(buffer[len-1]))
 374                len--;
 375        buffer[len] = 0;
 376
 377        /* Was it a detached head or an old-fashioned symlink? */
 378        if (!get_sha1_hex(buffer, result))
 379                return 0;
 380
 381        /* Symref? */
 382        if (strncmp(buffer, "ref:", 4))
 383                return -1;
 384        p = buffer + 4;
 385        while (isspace(*p))
 386                p++;
 387
 388        return resolve_gitlink_ref_recursive(name, pathlen, p, result, recursion+1);
 389}
 390
 391int resolve_gitlink_ref(const char *path, const char *refname, unsigned char *result)
 392{
 393        int len = strlen(path), retval;
 394        char *gitdir;
 395        const char *tmp;
 396
 397        while (len && path[len-1] == '/')
 398                len--;
 399        if (!len)
 400                return -1;
 401        gitdir = xmalloc(len + MAXREFLEN + 8);
 402        memcpy(gitdir, path, len);
 403        memcpy(gitdir + len, "/.git", 6);
 404        len += 5;
 405
 406        tmp = read_gitfile_gently(gitdir);
 407        if (tmp) {
 408                free(gitdir);
 409                len = strlen(tmp);
 410                gitdir = xmalloc(len + MAXREFLEN + 3);
 411                memcpy(gitdir, tmp, len);
 412        }
 413        gitdir[len] = '/';
 414        gitdir[++len] = '\0';
 415        retval = resolve_gitlink_ref_recursive(gitdir, len, refname, result, 0);
 416        free(gitdir);
 417        return retval;
 418}
 419
 420/*
 421 * If the "reading" argument is set, this function finds out what _object_
 422 * the ref points at by "reading" the ref.  The ref, if it is not symbolic,
 423 * has to exist, and if it is symbolic, it has to point at an existing ref,
 424 * because the "read" goes through the symref to the ref it points at.
 425 *
 426 * The access that is not "reading" may often be "writing", but does not
 427 * have to; it can be merely checking _where it leads to_. If it is a
 428 * prelude to "writing" to the ref, a write to a symref that points at
 429 * yet-to-be-born ref will create the real ref pointed by the symref.
 430 * reading=0 allows the caller to check where such a symref leads to.
 431 */
 432const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *flag)
 433{
 434        int depth = MAXDEPTH;
 435        ssize_t len;
 436        char buffer[256];
 437        static char ref_buffer[256];
 438
 439        if (flag)
 440                *flag = 0;
 441
 442        for (;;) {
 443                char path[PATH_MAX];
 444                struct stat st;
 445                char *buf;
 446                int fd;
 447
 448                if (--depth < 0)
 449                        return NULL;
 450
 451                git_snpath(path, sizeof(path), "%s", ref);
 452                /* Special case: non-existing file. */
 453                if (lstat(path, &st) < 0) {
 454                        struct ref_list *list = get_packed_refs();
 455                        while (list) {
 456                                if (!strcmp(ref, list->name)) {
 457                                        hashcpy(sha1, list->sha1);
 458                                        if (flag)
 459                                                *flag |= REF_ISPACKED;
 460                                        return ref;
 461                                }
 462                                list = list->next;
 463                        }
 464                        if (reading || errno != ENOENT)
 465                                return NULL;
 466                        hashclr(sha1);
 467                        return ref;
 468                }
 469
 470                /* Follow "normalized" - ie "refs/.." symlinks by hand */
 471                if (S_ISLNK(st.st_mode)) {
 472                        len = readlink(path, buffer, sizeof(buffer)-1);
 473                        if (len >= 5 && !memcmp("refs/", buffer, 5)) {
 474                                buffer[len] = 0;
 475                                strcpy(ref_buffer, buffer);
 476                                ref = ref_buffer;
 477                                if (flag)
 478                                        *flag |= REF_ISSYMREF;
 479                                continue;
 480                        }
 481                }
 482
 483                /* Is it a directory? */
 484                if (S_ISDIR(st.st_mode)) {
 485                        errno = EISDIR;
 486                        return NULL;
 487                }
 488
 489                /*
 490                 * Anything else, just open it and try to use it as
 491                 * a ref
 492                 */
 493                fd = open(path, O_RDONLY);
 494                if (fd < 0)
 495                        return NULL;
 496                len = read_in_full(fd, buffer, sizeof(buffer)-1);
 497                close(fd);
 498
 499                /*
 500                 * Is it a symbolic ref?
 501                 */
 502                if (len < 4 || memcmp("ref:", buffer, 4))
 503                        break;
 504                buf = buffer + 4;
 505                len -= 4;
 506                while (len && isspace(*buf))
 507                        buf++, len--;
 508                while (len && isspace(buf[len-1]))
 509                        len--;
 510                buf[len] = 0;
 511                memcpy(ref_buffer, buf, len + 1);
 512                ref = ref_buffer;
 513                if (flag)
 514                        *flag |= REF_ISSYMREF;
 515        }
 516        if (len < 40 || get_sha1_hex(buffer, sha1))
 517                return NULL;
 518        return ref;
 519}
 520
 521int read_ref(const char *ref, unsigned char *sha1)
 522{
 523        if (resolve_ref(ref, sha1, 1, NULL))
 524                return 0;
 525        return -1;
 526}
 527
 528#define DO_FOR_EACH_INCLUDE_BROKEN 01
 529static int do_one_ref(const char *base, each_ref_fn fn, int trim,
 530                      int flags, void *cb_data, struct ref_list *entry)
 531{
 532        if (strncmp(base, entry->name, trim))
 533                return 0;
 534        if (!(flags & DO_FOR_EACH_INCLUDE_BROKEN)) {
 535                if (is_null_sha1(entry->sha1))
 536                        return 0;
 537                if (!has_sha1_file(entry->sha1)) {
 538                        error("%s does not point to a valid object!", entry->name);
 539                        return 0;
 540                }
 541        }
 542        current_ref = entry;
 543        return fn(entry->name + trim, entry->sha1, entry->flag, cb_data);
 544}
 545
 546int peel_ref(const char *ref, unsigned char *sha1)
 547{
 548        int flag;
 549        unsigned char base[20];
 550        struct object *o;
 551
 552        if (current_ref && (current_ref->name == ref
 553                || !strcmp(current_ref->name, ref))) {
 554                if (current_ref->flag & REF_KNOWS_PEELED) {
 555                        hashcpy(sha1, current_ref->peeled);
 556                        return 0;
 557                }
 558                hashcpy(base, current_ref->sha1);
 559                goto fallback;
 560        }
 561
 562        if (!resolve_ref(ref, base, 1, &flag))
 563                return -1;
 564
 565        if ((flag & REF_ISPACKED)) {
 566                struct ref_list *list = get_packed_refs();
 567
 568                while (list) {
 569                        if (!strcmp(list->name, ref)) {
 570                                if (list->flag & REF_KNOWS_PEELED) {
 571                                        hashcpy(sha1, list->peeled);
 572                                        return 0;
 573                                }
 574                                /* older pack-refs did not leave peeled ones */
 575                                break;
 576                        }
 577                        list = list->next;
 578                }
 579        }
 580
 581fallback:
 582        o = parse_object(base);
 583        if (o && o->type == OBJ_TAG) {
 584                o = deref_tag(o, ref, 0);
 585                if (o) {
 586                        hashcpy(sha1, o->sha1);
 587                        return 0;
 588                }
 589        }
 590        return -1;
 591}
 592
 593static int do_for_each_ref(const char *base, each_ref_fn fn, int trim,
 594                           int flags, void *cb_data)
 595{
 596        int retval = 0;
 597        struct ref_list *packed = get_packed_refs();
 598        struct ref_list *loose = get_loose_refs();
 599
 600        struct ref_list *extra;
 601
 602        for (extra = extra_refs; extra; extra = extra->next)
 603                retval = do_one_ref(base, fn, trim, flags, cb_data, extra);
 604
 605        while (packed && loose) {
 606                struct ref_list *entry;
 607                int cmp = strcmp(packed->name, loose->name);
 608                if (!cmp) {
 609                        packed = packed->next;
 610                        continue;
 611                }
 612                if (cmp > 0) {
 613                        entry = loose;
 614                        loose = loose->next;
 615                } else {
 616                        entry = packed;
 617                        packed = packed->next;
 618                }
 619                retval = do_one_ref(base, fn, trim, flags, cb_data, entry);
 620                if (retval)
 621                        goto end_each;
 622        }
 623
 624        for (packed = packed ? packed : loose; packed; packed = packed->next) {
 625                retval = do_one_ref(base, fn, trim, flags, cb_data, packed);
 626                if (retval)
 627                        goto end_each;
 628        }
 629
 630end_each:
 631        current_ref = NULL;
 632        return retval;
 633}
 634
 635int head_ref(each_ref_fn fn, void *cb_data)
 636{
 637        unsigned char sha1[20];
 638        int flag;
 639
 640        if (resolve_ref("HEAD", sha1, 1, &flag))
 641                return fn("HEAD", sha1, flag, cb_data);
 642        return 0;
 643}
 644
 645int for_each_ref(each_ref_fn fn, void *cb_data)
 646{
 647        return do_for_each_ref("refs/", fn, 0, 0, cb_data);
 648}
 649
 650int for_each_tag_ref(each_ref_fn fn, void *cb_data)
 651{
 652        return do_for_each_ref("refs/tags/", fn, 10, 0, cb_data);
 653}
 654
 655int for_each_branch_ref(each_ref_fn fn, void *cb_data)
 656{
 657        return do_for_each_ref("refs/heads/", fn, 11, 0, cb_data);
 658}
 659
 660int for_each_remote_ref(each_ref_fn fn, void *cb_data)
 661{
 662        return do_for_each_ref("refs/remotes/", fn, 13, 0, cb_data);
 663}
 664
 665int for_each_rawref(each_ref_fn fn, void *cb_data)
 666{
 667        return do_for_each_ref("refs/", fn, 0,
 668                               DO_FOR_EACH_INCLUDE_BROKEN, cb_data);
 669}
 670
 671/*
 672 * Make sure "ref" is something reasonable to have under ".git/refs/";
 673 * We do not like it if:
 674 *
 675 * - any path component of it begins with ".", or
 676 * - it has double dots "..", or
 677 * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
 678 * - it ends with a "/".
 679 * - it ends with ".lock"
 680 */
 681
 682static inline int bad_ref_char(int ch)
 683{
 684        if (((unsigned) ch) <= ' ' ||
 685            ch == '~' || ch == '^' || ch == ':')
 686                return 1;
 687        /* 2.13 Pattern Matching Notation */
 688        if (ch == '?' || ch == '[') /* Unsupported */
 689                return 1;
 690        if (ch == '*') /* Supported at the end */
 691                return 2;
 692        return 0;
 693}
 694
 695int check_ref_format(const char *ref)
 696{
 697        int ch, level, bad_type, last;
 698        int ret = CHECK_REF_FORMAT_OK;
 699        const char *cp = ref;
 700
 701        level = 0;
 702        while (1) {
 703                while ((ch = *cp++) == '/')
 704                        ; /* tolerate duplicated slashes */
 705                if (!ch)
 706                        /* should not end with slashes */
 707                        return CHECK_REF_FORMAT_ERROR;
 708
 709                /* we are at the beginning of the path component */
 710                if (ch == '.')
 711                        return CHECK_REF_FORMAT_ERROR;
 712                bad_type = bad_ref_char(ch);
 713                if (bad_type) {
 714                        if (bad_type == 2 && (!*cp || *cp == '/') &&
 715                            ret == CHECK_REF_FORMAT_OK)
 716                                ret = CHECK_REF_FORMAT_WILDCARD;
 717                        else
 718                                return CHECK_REF_FORMAT_ERROR;
 719                }
 720
 721                last = ch;
 722                /* scan the rest of the path component */
 723                while ((ch = *cp++) != 0) {
 724                        bad_type = bad_ref_char(ch);
 725                        if (bad_type)
 726                                return CHECK_REF_FORMAT_ERROR;
 727                        if (ch == '/')
 728                                break;
 729                        if (last == '.' && ch == '.')
 730                                return CHECK_REF_FORMAT_ERROR;
 731                        if (last == '@' && ch == '{')
 732                                return CHECK_REF_FORMAT_ERROR;
 733                        last = ch;
 734                }
 735                level++;
 736                if (!ch) {
 737                        if (ref <= cp - 2 && cp[-2] == '.')
 738                                return CHECK_REF_FORMAT_ERROR;
 739                        if (level < 2)
 740                                return CHECK_REF_FORMAT_ONELEVEL;
 741                        if (has_extension(ref, ".lock"))
 742                                return CHECK_REF_FORMAT_ERROR;
 743                        return ret;
 744                }
 745        }
 746}
 747
 748const char *prettify_ref(const struct ref *ref)
 749{
 750        const char *name = ref->name;
 751        return name + (
 752                !prefixcmp(name, "refs/heads/") ? 11 :
 753                !prefixcmp(name, "refs/tags/") ? 10 :
 754                !prefixcmp(name, "refs/remotes/") ? 13 :
 755                0);
 756}
 757
 758const char *ref_rev_parse_rules[] = {
 759        "%.*s",
 760        "refs/%.*s",
 761        "refs/tags/%.*s",
 762        "refs/heads/%.*s",
 763        "refs/remotes/%.*s",
 764        "refs/remotes/%.*s/HEAD",
 765        NULL
 766};
 767
 768const char *ref_fetch_rules[] = {
 769        "%.*s",
 770        "refs/%.*s",
 771        "refs/heads/%.*s",
 772        NULL
 773};
 774
 775int refname_match(const char *abbrev_name, const char *full_name, const char **rules)
 776{
 777        const char **p;
 778        const int abbrev_name_len = strlen(abbrev_name);
 779
 780        for (p = rules; *p; p++) {
 781                if (!strcmp(full_name, mkpath(*p, abbrev_name_len, abbrev_name))) {
 782                        return 1;
 783                }
 784        }
 785
 786        return 0;
 787}
 788
 789static struct ref_lock *verify_lock(struct ref_lock *lock,
 790        const unsigned char *old_sha1, int mustexist)
 791{
 792        if (!resolve_ref(lock->ref_name, lock->old_sha1, mustexist, NULL)) {
 793                error("Can't verify ref %s", lock->ref_name);
 794                unlock_ref(lock);
 795                return NULL;
 796        }
 797        if (hashcmp(lock->old_sha1, old_sha1)) {
 798                error("Ref %s is at %s but expected %s", lock->ref_name,
 799                        sha1_to_hex(lock->old_sha1), sha1_to_hex(old_sha1));
 800                unlock_ref(lock);
 801                return NULL;
 802        }
 803        return lock;
 804}
 805
 806static int remove_empty_directories(const char *file)
 807{
 808        /* we want to create a file but there is a directory there;
 809         * if that is an empty directory (or a directory that contains
 810         * only empty directories), remove them.
 811         */
 812        struct strbuf path;
 813        int result;
 814
 815        strbuf_init(&path, 20);
 816        strbuf_addstr(&path, file);
 817
 818        result = remove_dir_recursively(&path, 1);
 819
 820        strbuf_release(&path);
 821
 822        return result;
 823}
 824
 825static int is_refname_available(const char *ref, const char *oldref,
 826                                struct ref_list *list, int quiet)
 827{
 828        int namlen = strlen(ref); /* e.g. 'foo/bar' */
 829        while (list) {
 830                /* list->name could be 'foo' or 'foo/bar/baz' */
 831                if (!oldref || strcmp(oldref, list->name)) {
 832                        int len = strlen(list->name);
 833                        int cmplen = (namlen < len) ? namlen : len;
 834                        const char *lead = (namlen < len) ? list->name : ref;
 835                        if (!strncmp(ref, list->name, cmplen) &&
 836                            lead[cmplen] == '/') {
 837                                if (!quiet)
 838                                        error("'%s' exists; cannot create '%s'",
 839                                              list->name, ref);
 840                                return 0;
 841                        }
 842                }
 843                list = list->next;
 844        }
 845        return 1;
 846}
 847
 848static struct ref_lock *lock_ref_sha1_basic(const char *ref, const unsigned char *old_sha1, int flags, int *type_p)
 849{
 850        char *ref_file;
 851        const char *orig_ref = ref;
 852        struct ref_lock *lock;
 853        int last_errno = 0;
 854        int type, lflags;
 855        int mustexist = (old_sha1 && !is_null_sha1(old_sha1));
 856        int missing = 0;
 857
 858        lock = xcalloc(1, sizeof(struct ref_lock));
 859        lock->lock_fd = -1;
 860
 861        ref = resolve_ref(ref, lock->old_sha1, mustexist, &type);
 862        if (!ref && errno == EISDIR) {
 863                /* we are trying to lock foo but we used to
 864                 * have foo/bar which now does not exist;
 865                 * it is normal for the empty directory 'foo'
 866                 * to remain.
 867                 */
 868                ref_file = git_path("%s", orig_ref);
 869                if (remove_empty_directories(ref_file)) {
 870                        last_errno = errno;
 871                        error("there are still refs under '%s'", orig_ref);
 872                        goto error_return;
 873                }
 874                ref = resolve_ref(orig_ref, lock->old_sha1, mustexist, &type);
 875        }
 876        if (type_p)
 877            *type_p = type;
 878        if (!ref) {
 879                last_errno = errno;
 880                error("unable to resolve reference %s: %s",
 881                        orig_ref, strerror(errno));
 882                goto error_return;
 883        }
 884        missing = is_null_sha1(lock->old_sha1);
 885        /* When the ref did not exist and we are creating it,
 886         * make sure there is no existing ref that is packed
 887         * whose name begins with our refname, nor a ref whose
 888         * name is a proper prefix of our refname.
 889         */
 890        if (missing &&
 891            !is_refname_available(ref, NULL, get_packed_refs(), 0))
 892                goto error_return;
 893
 894        lock->lk = xcalloc(1, sizeof(struct lock_file));
 895
 896        lflags = LOCK_DIE_ON_ERROR;
 897        if (flags & REF_NODEREF) {
 898                ref = orig_ref;
 899                lflags |= LOCK_NODEREF;
 900        }
 901        lock->ref_name = xstrdup(ref);
 902        lock->orig_ref_name = xstrdup(orig_ref);
 903        ref_file = git_path("%s", ref);
 904        if (missing)
 905                lock->force_write = 1;
 906        if ((flags & REF_NODEREF) && (type & REF_ISSYMREF))
 907                lock->force_write = 1;
 908
 909        if (safe_create_leading_directories(ref_file)) {
 910                last_errno = errno;
 911                error("unable to create directory for %s", ref_file);
 912                goto error_return;
 913        }
 914
 915        lock->lock_fd = hold_lock_file_for_update(lock->lk, ref_file, lflags);
 916        return old_sha1 ? verify_lock(lock, old_sha1, mustexist) : lock;
 917
 918 error_return:
 919        unlock_ref(lock);
 920        errno = last_errno;
 921        return NULL;
 922}
 923
 924struct ref_lock *lock_ref_sha1(const char *ref, const unsigned char *old_sha1)
 925{
 926        char refpath[PATH_MAX];
 927        if (check_ref_format(ref))
 928                return NULL;
 929        strcpy(refpath, mkpath("refs/%s", ref));
 930        return lock_ref_sha1_basic(refpath, old_sha1, 0, NULL);
 931}
 932
 933struct ref_lock *lock_any_ref_for_update(const char *ref, const unsigned char *old_sha1, int flags)
 934{
 935        switch (check_ref_format(ref)) {
 936        default:
 937                return NULL;
 938        case 0:
 939        case CHECK_REF_FORMAT_ONELEVEL:
 940                return lock_ref_sha1_basic(ref, old_sha1, flags, NULL);
 941        }
 942}
 943
 944static struct lock_file packlock;
 945
 946static int repack_without_ref(const char *refname)
 947{
 948        struct ref_list *list, *packed_ref_list;
 949        int fd;
 950        int found = 0;
 951
 952        packed_ref_list = get_packed_refs();
 953        for (list = packed_ref_list; list; list = list->next) {
 954                if (!strcmp(refname, list->name)) {
 955                        found = 1;
 956                        break;
 957                }
 958        }
 959        if (!found)
 960                return 0;
 961        fd = hold_lock_file_for_update(&packlock, git_path("packed-refs"), 0);
 962        if (fd < 0)
 963                return error("cannot delete '%s' from packed refs", refname);
 964
 965        for (list = packed_ref_list; list; list = list->next) {
 966                char line[PATH_MAX + 100];
 967                int len;
 968
 969                if (!strcmp(refname, list->name))
 970                        continue;
 971                len = snprintf(line, sizeof(line), "%s %s\n",
 972                               sha1_to_hex(list->sha1), list->name);
 973                /* this should not happen but just being defensive */
 974                if (len > sizeof(line))
 975                        die("too long a refname '%s'", list->name);
 976                write_or_die(fd, line, len);
 977        }
 978        return commit_lock_file(&packlock);
 979}
 980
 981int delete_ref(const char *refname, const unsigned char *sha1, int delopt)
 982{
 983        struct ref_lock *lock;
 984        int err, i = 0, ret = 0, flag = 0;
 985
 986        lock = lock_ref_sha1_basic(refname, sha1, 0, &flag);
 987        if (!lock)
 988                return 1;
 989        if (!(flag & REF_ISPACKED) || flag & REF_ISSYMREF) {
 990                /* loose */
 991                const char *path;
 992
 993                if (!(delopt & REF_NODEREF)) {
 994                        i = strlen(lock->lk->filename) - 5; /* .lock */
 995                        lock->lk->filename[i] = 0;
 996                        path = lock->lk->filename;
 997                } else {
 998                        path = git_path("%s", refname);
 999                }
1000                err = unlink(path);
1001                if (err && errno != ENOENT) {
1002                        ret = 1;
1003                        error("unlink(%s) failed: %s",
1004                              path, strerror(errno));
1005                }
1006                if (!(delopt & REF_NODEREF))
1007                        lock->lk->filename[i] = '.';
1008        }
1009        /* removing the loose one could have resurrected an earlier
1010         * packed one.  Also, if it was not loose we need to repack
1011         * without it.
1012         */
1013        ret |= repack_without_ref(refname);
1014
1015        err = unlink(git_path("logs/%s", lock->ref_name));
1016        if (err && errno != ENOENT)
1017                warning("unlink(%s) failed: %s",
1018                        git_path("logs/%s", lock->ref_name), strerror(errno));
1019        invalidate_cached_refs();
1020        unlock_ref(lock);
1021        return ret;
1022}
1023
1024int rename_ref(const char *oldref, const char *newref, const char *logmsg)
1025{
1026        static const char renamed_ref[] = "RENAMED-REF";
1027        unsigned char sha1[20], orig_sha1[20];
1028        int flag = 0, logmoved = 0;
1029        struct ref_lock *lock;
1030        struct stat loginfo;
1031        int log = !lstat(git_path("logs/%s", oldref), &loginfo);
1032        const char *symref = NULL;
1033
1034        if (log && S_ISLNK(loginfo.st_mode))
1035                return error("reflog for %s is a symlink", oldref);
1036
1037        symref = resolve_ref(oldref, orig_sha1, 1, &flag);
1038        if (flag & REF_ISSYMREF)
1039                return error("refname %s is a symbolic ref, renaming it is not supported",
1040                        oldref);
1041        if (!symref)
1042                return error("refname %s not found", oldref);
1043
1044        if (!is_refname_available(newref, oldref, get_packed_refs(), 0))
1045                return 1;
1046
1047        if (!is_refname_available(newref, oldref, get_loose_refs(), 0))
1048                return 1;
1049
1050        lock = lock_ref_sha1_basic(renamed_ref, NULL, 0, NULL);
1051        if (!lock)
1052                return error("unable to lock %s", renamed_ref);
1053        lock->force_write = 1;
1054        if (write_ref_sha1(lock, orig_sha1, logmsg))
1055                return error("unable to save current sha1 in %s", renamed_ref);
1056
1057        if (log && rename(git_path("logs/%s", oldref), git_path("tmp-renamed-log")))
1058                return error("unable to move logfile logs/%s to tmp-renamed-log: %s",
1059                        oldref, strerror(errno));
1060
1061        if (delete_ref(oldref, orig_sha1, REF_NODEREF)) {
1062                error("unable to delete old %s", oldref);
1063                goto rollback;
1064        }
1065
1066        if (resolve_ref(newref, sha1, 1, &flag) && delete_ref(newref, sha1, REF_NODEREF)) {
1067                if (errno==EISDIR) {
1068                        if (remove_empty_directories(git_path("%s", newref))) {
1069                                error("Directory not empty: %s", newref);
1070                                goto rollback;
1071                        }
1072                } else {
1073                        error("unable to delete existing %s", newref);
1074                        goto rollback;
1075                }
1076        }
1077
1078        if (log && safe_create_leading_directories(git_path("logs/%s", newref))) {
1079                error("unable to create directory for %s", newref);
1080                goto rollback;
1081        }
1082
1083 retry:
1084        if (log && rename(git_path("tmp-renamed-log"), git_path("logs/%s", newref))) {
1085                if (errno==EISDIR || errno==ENOTDIR) {
1086                        /*
1087                         * rename(a, b) when b is an existing
1088                         * directory ought to result in ISDIR, but
1089                         * Solaris 5.8 gives ENOTDIR.  Sheesh.
1090                         */
1091                        if (remove_empty_directories(git_path("logs/%s", newref))) {
1092                                error("Directory not empty: logs/%s", newref);
1093                                goto rollback;
1094                        }
1095                        goto retry;
1096                } else {
1097                        error("unable to move logfile tmp-renamed-log to logs/%s: %s",
1098                                newref, strerror(errno));
1099                        goto rollback;
1100                }
1101        }
1102        logmoved = log;
1103
1104        lock = lock_ref_sha1_basic(newref, NULL, 0, NULL);
1105        if (!lock) {
1106                error("unable to lock %s for update", newref);
1107                goto rollback;
1108        }
1109        lock->force_write = 1;
1110        hashcpy(lock->old_sha1, orig_sha1);
1111        if (write_ref_sha1(lock, orig_sha1, logmsg)) {
1112                error("unable to write current sha1 into %s", newref);
1113                goto rollback;
1114        }
1115
1116        return 0;
1117
1118 rollback:
1119        lock = lock_ref_sha1_basic(oldref, NULL, 0, NULL);
1120        if (!lock) {
1121                error("unable to lock %s for rollback", oldref);
1122                goto rollbacklog;
1123        }
1124
1125        lock->force_write = 1;
1126        flag = log_all_ref_updates;
1127        log_all_ref_updates = 0;
1128        if (write_ref_sha1(lock, orig_sha1, NULL))
1129                error("unable to write current sha1 into %s", oldref);
1130        log_all_ref_updates = flag;
1131
1132 rollbacklog:
1133        if (logmoved && rename(git_path("logs/%s", newref), git_path("logs/%s", oldref)))
1134                error("unable to restore logfile %s from %s: %s",
1135                        oldref, newref, strerror(errno));
1136        if (!logmoved && log &&
1137            rename(git_path("tmp-renamed-log"), git_path("logs/%s", oldref)))
1138                error("unable to restore logfile %s from tmp-renamed-log: %s",
1139                        oldref, strerror(errno));
1140
1141        return 1;
1142}
1143
1144int close_ref(struct ref_lock *lock)
1145{
1146        if (close_lock_file(lock->lk))
1147                return -1;
1148        lock->lock_fd = -1;
1149        return 0;
1150}
1151
1152int commit_ref(struct ref_lock *lock)
1153{
1154        if (commit_lock_file(lock->lk))
1155                return -1;
1156        lock->lock_fd = -1;
1157        return 0;
1158}
1159
1160void unlock_ref(struct ref_lock *lock)
1161{
1162        /* Do not free lock->lk -- atexit() still looks at them */
1163        if (lock->lk)
1164                rollback_lock_file(lock->lk);
1165        free(lock->ref_name);
1166        free(lock->orig_ref_name);
1167        free(lock);
1168}
1169
1170/*
1171 * copy the reflog message msg to buf, which has been allocated sufficiently
1172 * large, while cleaning up the whitespaces.  Especially, convert LF to space,
1173 * because reflog file is one line per entry.
1174 */
1175static int copy_msg(char *buf, const char *msg)
1176{
1177        char *cp = buf;
1178        char c;
1179        int wasspace = 1;
1180
1181        *cp++ = '\t';
1182        while ((c = *msg++)) {
1183                if (wasspace && isspace(c))
1184                        continue;
1185                wasspace = isspace(c);
1186                if (wasspace)
1187                        c = ' ';
1188                *cp++ = c;
1189        }
1190        while (buf < cp && isspace(cp[-1]))
1191                cp--;
1192        *cp++ = '\n';
1193        return cp - buf;
1194}
1195
1196static int log_ref_write(const char *ref_name, const unsigned char *old_sha1,
1197                         const unsigned char *new_sha1, const char *msg)
1198{
1199        int logfd, written, oflags = O_APPEND | O_WRONLY;
1200        unsigned maxlen, len;
1201        int msglen;
1202        char log_file[PATH_MAX];
1203        char *logrec;
1204        const char *committer;
1205
1206        if (log_all_ref_updates < 0)
1207                log_all_ref_updates = !is_bare_repository();
1208
1209        git_snpath(log_file, sizeof(log_file), "logs/%s", ref_name);
1210
1211        if (log_all_ref_updates &&
1212            (!prefixcmp(ref_name, "refs/heads/") ||
1213             !prefixcmp(ref_name, "refs/remotes/") ||
1214             !strcmp(ref_name, "HEAD"))) {
1215                if (safe_create_leading_directories(log_file) < 0)
1216                        return error("unable to create directory for %s",
1217                                     log_file);
1218                oflags |= O_CREAT;
1219        }
1220
1221        logfd = open(log_file, oflags, 0666);
1222        if (logfd < 0) {
1223                if (!(oflags & O_CREAT) && errno == ENOENT)
1224                        return 0;
1225
1226                if ((oflags & O_CREAT) && errno == EISDIR) {
1227                        if (remove_empty_directories(log_file)) {
1228                                return error("There are still logs under '%s'",
1229                                             log_file);
1230                        }
1231                        logfd = open(log_file, oflags, 0666);
1232                }
1233
1234                if (logfd < 0)
1235                        return error("Unable to append to %s: %s",
1236                                     log_file, strerror(errno));
1237        }
1238
1239        adjust_shared_perm(log_file);
1240
1241        msglen = msg ? strlen(msg) : 0;
1242        committer = git_committer_info(0);
1243        maxlen = strlen(committer) + msglen + 100;
1244        logrec = xmalloc(maxlen);
1245        len = sprintf(logrec, "%s %s %s\n",
1246                      sha1_to_hex(old_sha1),
1247                      sha1_to_hex(new_sha1),
1248                      committer);
1249        if (msglen)
1250                len += copy_msg(logrec + len - 1, msg) - 1;
1251        written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1;
1252        free(logrec);
1253        if (close(logfd) != 0 || written != len)
1254                return error("Unable to append to %s", log_file);
1255        return 0;
1256}
1257
1258static int is_branch(const char *refname)
1259{
1260        return !strcmp(refname, "HEAD") || !prefixcmp(refname, "refs/heads/");
1261}
1262
1263int write_ref_sha1(struct ref_lock *lock,
1264        const unsigned char *sha1, const char *logmsg)
1265{
1266        static char term = '\n';
1267        struct object *o;
1268
1269        if (!lock)
1270                return -1;
1271        if (!lock->force_write && !hashcmp(lock->old_sha1, sha1)) {
1272                unlock_ref(lock);
1273                return 0;
1274        }
1275        o = parse_object(sha1);
1276        if (!o) {
1277                error("Trying to write ref %s with nonexistant object %s",
1278                        lock->ref_name, sha1_to_hex(sha1));
1279                unlock_ref(lock);
1280                return -1;
1281        }
1282        if (o->type != OBJ_COMMIT && is_branch(lock->ref_name)) {
1283                error("Trying to write non-commit object %s to branch %s",
1284                        sha1_to_hex(sha1), lock->ref_name);
1285                unlock_ref(lock);
1286                return -1;
1287        }
1288        if (write_in_full(lock->lock_fd, sha1_to_hex(sha1), 40) != 40 ||
1289            write_in_full(lock->lock_fd, &term, 1) != 1
1290                || close_ref(lock) < 0) {
1291                error("Couldn't write %s", lock->lk->filename);
1292                unlock_ref(lock);
1293                return -1;
1294        }
1295        invalidate_cached_refs();
1296        if (log_ref_write(lock->ref_name, lock->old_sha1, sha1, logmsg) < 0 ||
1297            (strcmp(lock->ref_name, lock->orig_ref_name) &&
1298             log_ref_write(lock->orig_ref_name, lock->old_sha1, sha1, logmsg) < 0)) {
1299                unlock_ref(lock);
1300                return -1;
1301        }
1302        if (strcmp(lock->orig_ref_name, "HEAD") != 0) {
1303                /*
1304                 * Special hack: If a branch is updated directly and HEAD
1305                 * points to it (may happen on the remote side of a push
1306                 * for example) then logically the HEAD reflog should be
1307                 * updated too.
1308                 * A generic solution implies reverse symref information,
1309                 * but finding all symrefs pointing to the given branch
1310                 * would be rather costly for this rare event (the direct
1311                 * update of a branch) to be worth it.  So let's cheat and
1312                 * check with HEAD only which should cover 99% of all usage
1313                 * scenarios (even 100% of the default ones).
1314                 */
1315                unsigned char head_sha1[20];
1316                int head_flag;
1317                const char *head_ref;
1318                head_ref = resolve_ref("HEAD", head_sha1, 1, &head_flag);
1319                if (head_ref && (head_flag & REF_ISSYMREF) &&
1320                    !strcmp(head_ref, lock->ref_name))
1321                        log_ref_write("HEAD", lock->old_sha1, sha1, logmsg);
1322        }
1323        if (commit_ref(lock)) {
1324                error("Couldn't set %s", lock->ref_name);
1325                unlock_ref(lock);
1326                return -1;
1327        }
1328        unlock_ref(lock);
1329        return 0;
1330}
1331
1332int create_symref(const char *ref_target, const char *refs_heads_master,
1333                  const char *logmsg)
1334{
1335        const char *lockpath;
1336        char ref[1000];
1337        int fd, len, written;
1338        char *git_HEAD = git_pathdup("%s", ref_target);
1339        unsigned char old_sha1[20], new_sha1[20];
1340
1341        if (logmsg && read_ref(ref_target, old_sha1))
1342                hashclr(old_sha1);
1343
1344        if (safe_create_leading_directories(git_HEAD) < 0)
1345                return error("unable to create directory for %s", git_HEAD);
1346
1347#ifndef NO_SYMLINK_HEAD
1348        if (prefer_symlink_refs) {
1349                unlink(git_HEAD);
1350                if (!symlink(refs_heads_master, git_HEAD))
1351                        goto done;
1352                fprintf(stderr, "no symlink - falling back to symbolic ref\n");
1353        }
1354#endif
1355
1356        len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
1357        if (sizeof(ref) <= len) {
1358                error("refname too long: %s", refs_heads_master);
1359                goto error_free_return;
1360        }
1361        lockpath = mkpath("%s.lock", git_HEAD);
1362        fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);
1363        if (fd < 0) {
1364                error("Unable to open %s for writing", lockpath);
1365                goto error_free_return;
1366        }
1367        written = write_in_full(fd, ref, len);
1368        if (close(fd) != 0 || written != len) {
1369                error("Unable to write to %s", lockpath);
1370                goto error_unlink_return;
1371        }
1372        if (rename(lockpath, git_HEAD) < 0) {
1373                error("Unable to create %s", git_HEAD);
1374                goto error_unlink_return;
1375        }
1376        if (adjust_shared_perm(git_HEAD)) {
1377                error("Unable to fix permissions on %s", lockpath);
1378        error_unlink_return:
1379                unlink(lockpath);
1380        error_free_return:
1381                free(git_HEAD);
1382                return -1;
1383        }
1384
1385#ifndef NO_SYMLINK_HEAD
1386        done:
1387#endif
1388        if (logmsg && !read_ref(refs_heads_master, new_sha1))
1389                log_ref_write(ref_target, old_sha1, new_sha1, logmsg);
1390
1391        free(git_HEAD);
1392        return 0;
1393}
1394
1395static char *ref_msg(const char *line, const char *endp)
1396{
1397        const char *ep;
1398        line += 82;
1399        ep = memchr(line, '\n', endp - line);
1400        if (!ep)
1401                ep = endp;
1402        return xmemdupz(line, ep - line);
1403}
1404
1405int 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)
1406{
1407        const char *logfile, *logdata, *logend, *rec, *lastgt, *lastrec;
1408        char *tz_c;
1409        int logfd, tz, reccnt = 0;
1410        struct stat st;
1411        unsigned long date;
1412        unsigned char logged_sha1[20];
1413        void *log_mapped;
1414        size_t mapsz;
1415
1416        logfile = git_path("logs/%s", ref);
1417        logfd = open(logfile, O_RDONLY, 0);
1418        if (logfd < 0)
1419                die("Unable to read log %s: %s", logfile, strerror(errno));
1420        fstat(logfd, &st);
1421        if (!st.st_size)
1422                die("Log %s is empty.", logfile);
1423        mapsz = xsize_t(st.st_size);
1424        log_mapped = xmmap(NULL, mapsz, PROT_READ, MAP_PRIVATE, logfd, 0);
1425        logdata = log_mapped;
1426        close(logfd);
1427
1428        lastrec = NULL;
1429        rec = logend = logdata + st.st_size;
1430        while (logdata < rec) {
1431                reccnt++;
1432                if (logdata < rec && *(rec-1) == '\n')
1433                        rec--;
1434                lastgt = NULL;
1435                while (logdata < rec && *(rec-1) != '\n') {
1436                        rec--;
1437                        if (*rec == '>')
1438                                lastgt = rec;
1439                }
1440                if (!lastgt)
1441                        die("Log %s is corrupt.", logfile);
1442                date = strtoul(lastgt + 1, &tz_c, 10);
1443                if (date <= at_time || cnt == 0) {
1444                        tz = strtoul(tz_c, NULL, 10);
1445                        if (msg)
1446                                *msg = ref_msg(rec, logend);
1447                        if (cutoff_time)
1448                                *cutoff_time = date;
1449                        if (cutoff_tz)
1450                                *cutoff_tz = tz;
1451                        if (cutoff_cnt)
1452                                *cutoff_cnt = reccnt - 1;
1453                        if (lastrec) {
1454                                if (get_sha1_hex(lastrec, logged_sha1))
1455                                        die("Log %s is corrupt.", logfile);
1456                                if (get_sha1_hex(rec + 41, sha1))
1457                                        die("Log %s is corrupt.", logfile);
1458                                if (hashcmp(logged_sha1, sha1)) {
1459                                        warning("Log %s has gap after %s.",
1460                                                logfile, show_date(date, tz, DATE_RFC2822));
1461                                }
1462                        }
1463                        else if (date == at_time) {
1464                                if (get_sha1_hex(rec + 41, sha1))
1465                                        die("Log %s is corrupt.", logfile);
1466                        }
1467                        else {
1468                                if (get_sha1_hex(rec + 41, logged_sha1))
1469                                        die("Log %s is corrupt.", logfile);
1470                                if (hashcmp(logged_sha1, sha1)) {
1471                                        warning("Log %s unexpectedly ended on %s.",
1472                                                logfile, show_date(date, tz, DATE_RFC2822));
1473                                }
1474                        }
1475                        munmap(log_mapped, mapsz);
1476                        return 0;
1477                }
1478                lastrec = rec;
1479                if (cnt > 0)
1480                        cnt--;
1481        }
1482
1483        rec = logdata;
1484        while (rec < logend && *rec != '>' && *rec != '\n')
1485                rec++;
1486        if (rec == logend || *rec == '\n')
1487                die("Log %s is corrupt.", logfile);
1488        date = strtoul(rec + 1, &tz_c, 10);
1489        tz = strtoul(tz_c, NULL, 10);
1490        if (get_sha1_hex(logdata, sha1))
1491                die("Log %s is corrupt.", logfile);
1492        if (is_null_sha1(sha1)) {
1493                if (get_sha1_hex(logdata + 41, sha1))
1494                        die("Log %s is corrupt.", logfile);
1495        }
1496        if (msg)
1497                *msg = ref_msg(logdata, logend);
1498        munmap(log_mapped, mapsz);
1499
1500        if (cutoff_time)
1501                *cutoff_time = date;
1502        if (cutoff_tz)
1503                *cutoff_tz = tz;
1504        if (cutoff_cnt)
1505                *cutoff_cnt = reccnt;
1506        return 1;
1507}
1508
1509int for_each_recent_reflog_ent(const char *ref, each_reflog_ent_fn fn, long ofs, void *cb_data)
1510{
1511        const char *logfile;
1512        FILE *logfp;
1513        char buf[1024];
1514        int ret = 0;
1515
1516        logfile = git_path("logs/%s", ref);
1517        logfp = fopen(logfile, "r");
1518        if (!logfp)
1519                return -1;
1520
1521        if (ofs) {
1522                struct stat statbuf;
1523                if (fstat(fileno(logfp), &statbuf) ||
1524                    statbuf.st_size < ofs ||
1525                    fseek(logfp, -ofs, SEEK_END) ||
1526                    fgets(buf, sizeof(buf), logfp))
1527                        return -1;
1528        }
1529
1530        while (fgets(buf, sizeof(buf), logfp)) {
1531                unsigned char osha1[20], nsha1[20];
1532                char *email_end, *message;
1533                unsigned long timestamp;
1534                int len, tz;
1535
1536                /* old SP new SP name <email> SP time TAB msg LF */
1537                len = strlen(buf);
1538                if (len < 83 || buf[len-1] != '\n' ||
1539                    get_sha1_hex(buf, osha1) || buf[40] != ' ' ||
1540                    get_sha1_hex(buf + 41, nsha1) || buf[81] != ' ' ||
1541                    !(email_end = strchr(buf + 82, '>')) ||
1542                    email_end[1] != ' ' ||
1543                    !(timestamp = strtoul(email_end + 2, &message, 10)) ||
1544                    !message || message[0] != ' ' ||
1545                    (message[1] != '+' && message[1] != '-') ||
1546                    !isdigit(message[2]) || !isdigit(message[3]) ||
1547                    !isdigit(message[4]) || !isdigit(message[5]))
1548                        continue; /* corrupt? */
1549                email_end[1] = '\0';
1550                tz = strtol(message + 1, NULL, 10);
1551                if (message[6] != '\t')
1552                        message += 6;
1553                else
1554                        message += 7;
1555                ret = fn(osha1, nsha1, buf+82, timestamp, tz, message, cb_data);
1556                if (ret)
1557                        break;
1558        }
1559        fclose(logfp);
1560        return ret;
1561}
1562
1563int for_each_reflog_ent(const char *ref, each_reflog_ent_fn fn, void *cb_data)
1564{
1565        return for_each_recent_reflog_ent(ref, fn, 0, cb_data);
1566}
1567
1568static int do_for_each_reflog(const char *base, each_ref_fn fn, void *cb_data)
1569{
1570        DIR *dir = opendir(git_path("logs/%s", base));
1571        int retval = 0;
1572
1573        if (dir) {
1574                struct dirent *de;
1575                int baselen = strlen(base);
1576                char *log = xmalloc(baselen + 257);
1577
1578                memcpy(log, base, baselen);
1579                if (baselen && base[baselen-1] != '/')
1580                        log[baselen++] = '/';
1581
1582                while ((de = readdir(dir)) != NULL) {
1583                        struct stat st;
1584                        int namelen;
1585
1586                        if (de->d_name[0] == '.')
1587                                continue;
1588                        namelen = strlen(de->d_name);
1589                        if (namelen > 255)
1590                                continue;
1591                        if (has_extension(de->d_name, ".lock"))
1592                                continue;
1593                        memcpy(log + baselen, de->d_name, namelen+1);
1594                        if (stat(git_path("logs/%s", log), &st) < 0)
1595                                continue;
1596                        if (S_ISDIR(st.st_mode)) {
1597                                retval = do_for_each_reflog(log, fn, cb_data);
1598                        } else {
1599                                unsigned char sha1[20];
1600                                if (!resolve_ref(log, sha1, 0, NULL))
1601                                        retval = error("bad ref for %s", log);
1602                                else
1603                                        retval = fn(log, sha1, 0, cb_data);
1604                        }
1605                        if (retval)
1606                                break;
1607                }
1608                free(log);
1609                closedir(dir);
1610        }
1611        else if (*base)
1612                return errno;
1613        return retval;
1614}
1615
1616int for_each_reflog(each_ref_fn fn, void *cb_data)
1617{
1618        return do_for_each_reflog("", fn, cb_data);
1619}
1620
1621int update_ref(const char *action, const char *refname,
1622                const unsigned char *sha1, const unsigned char *oldval,
1623                int flags, enum action_on_err onerr)
1624{
1625        static struct ref_lock *lock;
1626        lock = lock_any_ref_for_update(refname, oldval, flags);
1627        if (!lock) {
1628                const char *str = "Cannot lock the ref '%s'.";
1629                switch (onerr) {
1630                case MSG_ON_ERR: error(str, refname); break;
1631                case DIE_ON_ERR: die(str, refname); break;
1632                case QUIET_ON_ERR: break;
1633                }
1634                return 1;
1635        }
1636        if (write_ref_sha1(lock, sha1, action) < 0) {
1637                const char *str = "Cannot update the ref '%s'.";
1638                switch (onerr) {
1639                case MSG_ON_ERR: error(str, refname); break;
1640                case DIE_ON_ERR: die(str, refname); break;
1641                case QUIET_ON_ERR: break;
1642                }
1643                return 1;
1644        }
1645        return 0;
1646}
1647
1648struct ref *find_ref_by_name(const struct ref *list, const char *name)
1649{
1650        for ( ; list; list = list->next)
1651                if (!strcmp(list->name, name))
1652                        return (struct ref *)list;
1653        return NULL;
1654}