Andrew's git - gitweb.git/blob

76a0ad36db5e27a220d11a37f5af4f98bf1eb3d7
   1#include "cache.h"
   2#include "object.h"
   3#include "blob.h"
   4#include "tree.h"
   5#include "tree-walk.h"
   6#include "commit.h"
   7#include "tag.h"
   8#include "fsck.h"
   9#include "refs.h"
  10#include "utf8.h"
  11#include "sha1-array.h"
  12#include "decorate.h"
  13
  14#define FSCK_FATAL -1
  15#define FSCK_INFO -2
  16
  17#define FOREACH_MSG_ID(FUNC) \
  18        /* fatal errors */ \
  19        FUNC(NUL_IN_HEADER, FATAL) \
  20        FUNC(UNTERMINATED_HEADER, FATAL) \
  21        /* errors */ \
  22        FUNC(BAD_DATE, ERROR) \
  23        FUNC(BAD_DATE_OVERFLOW, ERROR) \
  24        FUNC(BAD_EMAIL, ERROR) \
  25        FUNC(BAD_NAME, ERROR) \
  26        FUNC(BAD_OBJECT_SHA1, ERROR) \
  27        FUNC(BAD_PARENT_SHA1, ERROR) \
  28        FUNC(BAD_TAG_OBJECT, ERROR) \
  29        FUNC(BAD_TIMEZONE, ERROR) \
  30        FUNC(BAD_TREE, ERROR) \
  31        FUNC(BAD_TREE_SHA1, ERROR) \
  32        FUNC(BAD_TYPE, ERROR) \
  33        FUNC(DUPLICATE_ENTRIES, ERROR) \
  34        FUNC(MISSING_AUTHOR, ERROR) \
  35        FUNC(MISSING_COMMITTER, ERROR) \
  36        FUNC(MISSING_EMAIL, ERROR) \
  37        FUNC(MISSING_GRAFT, ERROR) \
  38        FUNC(MISSING_NAME_BEFORE_EMAIL, ERROR) \
  39        FUNC(MISSING_OBJECT, ERROR) \
  40        FUNC(MISSING_PARENT, ERROR) \
  41        FUNC(MISSING_SPACE_BEFORE_DATE, ERROR) \
  42        FUNC(MISSING_SPACE_BEFORE_EMAIL, ERROR) \
  43        FUNC(MISSING_TAG, ERROR) \
  44        FUNC(MISSING_TAG_ENTRY, ERROR) \
  45        FUNC(MISSING_TAG_OBJECT, ERROR) \
  46        FUNC(MISSING_TREE, ERROR) \
  47        FUNC(MISSING_TYPE, ERROR) \
  48        FUNC(MISSING_TYPE_ENTRY, ERROR) \
  49        FUNC(MULTIPLE_AUTHORS, ERROR) \
  50        FUNC(TAG_OBJECT_NOT_TAG, ERROR) \
  51        FUNC(TREE_NOT_SORTED, ERROR) \
  52        FUNC(UNKNOWN_TYPE, ERROR) \
  53        FUNC(ZERO_PADDED_DATE, ERROR) \
  54        /* warnings */ \
  55        FUNC(BAD_FILEMODE, WARN) \
  56        FUNC(EMPTY_NAME, WARN) \
  57        FUNC(FULL_PATHNAME, WARN) \
  58        FUNC(HAS_DOT, WARN) \
  59        FUNC(HAS_DOTDOT, WARN) \
  60        FUNC(HAS_DOTGIT, WARN) \
  61        FUNC(NULL_SHA1, WARN) \
  62        FUNC(ZERO_PADDED_FILEMODE, WARN) \
  63        FUNC(NUL_IN_COMMIT, WARN) \
  64        /* infos (reported as warnings, but ignored by default) */ \
  65        FUNC(BAD_TAG_NAME, INFO) \
  66        FUNC(MISSING_TAGGER_ENTRY, INFO)
  67
  68#define MSG_ID(id, msg_type) FSCK_MSG_##id,
  69enum fsck_msg_id {
  70        FOREACH_MSG_ID(MSG_ID)
  71        FSCK_MSG_MAX
  72};
  73#undef MSG_ID
  74
  75#define STR(x) #x
  76#define MSG_ID(id, msg_type) { STR(id), NULL, FSCK_##msg_type },
  77static struct {
  78        const char *id_string;
  79        const char *downcased;
  80        int msg_type;
  81} msg_id_info[FSCK_MSG_MAX + 1] = {
  82        FOREACH_MSG_ID(MSG_ID)
  83        { NULL, NULL, -1 }
  84};
  85#undef MSG_ID
  86
  87static int parse_msg_id(const char *text)
  88{
  89        int i;
  90
  91        if (!msg_id_info[0].downcased) {
  92                /* convert id_string to lower case, without underscores. */
  93                for (i = 0; i < FSCK_MSG_MAX; i++) {
  94                        const char *p = msg_id_info[i].id_string;
  95                        int len = strlen(p);
  96                        char *q = xmalloc(len);
  97
  98                        msg_id_info[i].downcased = q;
  99                        while (*p)
 100                                if (*p == '_')
 101                                        p++;
 102                                else
 103                                        *(q)++ = tolower(*(p)++);
 104                        *q = '\0';
 105                }
 106        }
 107
 108        for (i = 0; i < FSCK_MSG_MAX; i++)
 109                if (!strcmp(text, msg_id_info[i].downcased))
 110                        return i;
 111
 112        return -1;
 113}
 114
 115static int fsck_msg_type(enum fsck_msg_id msg_id,
 116        struct fsck_options *options)
 117{
 118        int msg_type;
 119
 120        assert(msg_id >= 0 && msg_id < FSCK_MSG_MAX);
 121
 122        if (options->msg_type)
 123                msg_type = options->msg_type[msg_id];
 124        else {
 125                msg_type = msg_id_info[msg_id].msg_type;
 126                if (options->strict && msg_type == FSCK_WARN)
 127                        msg_type = FSCK_ERROR;
 128        }
 129
 130        return msg_type;
 131}
 132
 133static void init_skiplist(struct fsck_options *options, const char *path)
 134{
 135        static struct oid_array skiplist = OID_ARRAY_INIT;
 136        int sorted, fd;
 137        char buffer[GIT_MAX_HEXSZ + 1];
 138        struct object_id oid;
 139
 140        if (options->skiplist)
 141                sorted = options->skiplist->sorted;
 142        else {
 143                sorted = 1;
 144                options->skiplist = &skiplist;
 145        }
 146
 147        fd = open(path, O_RDONLY);
 148        if (fd < 0)
 149                die("Could not open skip list: %s", path);
 150        for (;;) {
 151                const char *p;
 152                int result = read_in_full(fd, buffer, sizeof(buffer));
 153                if (result < 0)
 154                        die_errno("Could not read '%s'", path);
 155                if (!result)
 156                        break;
 157                if (parse_oid_hex(buffer, &oid, &p) || *p != '\n')
 158                        die("Invalid SHA-1: %s", buffer);
 159                oid_array_append(&skiplist, &oid);
 160                if (sorted && skiplist.nr > 1 &&
 161                                oidcmp(&skiplist.oid[skiplist.nr - 2],
 162                                       &oid) > 0)
 163                        sorted = 0;
 164        }
 165        close(fd);
 166
 167        if (sorted)
 168                skiplist.sorted = 1;
 169}
 170
 171static int parse_msg_type(const char *str)
 172{
 173        if (!strcmp(str, "error"))
 174                return FSCK_ERROR;
 175        else if (!strcmp(str, "warn"))
 176                return FSCK_WARN;
 177        else if (!strcmp(str, "ignore"))
 178                return FSCK_IGNORE;
 179        else
 180                die("Unknown fsck message type: '%s'", str);
 181}
 182
 183int is_valid_msg_type(const char *msg_id, const char *msg_type)
 184{
 185        if (parse_msg_id(msg_id) < 0)
 186                return 0;
 187        parse_msg_type(msg_type);
 188        return 1;
 189}
 190
 191void fsck_set_msg_type(struct fsck_options *options,
 192                const char *msg_id, const char *msg_type)
 193{
 194        int id = parse_msg_id(msg_id), type;
 195
 196        if (id < 0)
 197                die("Unhandled message id: %s", msg_id);
 198        type = parse_msg_type(msg_type);
 199
 200        if (type != FSCK_ERROR && msg_id_info[id].msg_type == FSCK_FATAL)
 201                die("Cannot demote %s to %s", msg_id, msg_type);
 202
 203        if (!options->msg_type) {
 204                int i;
 205                int *msg_type;
 206                ALLOC_ARRAY(msg_type, FSCK_MSG_MAX);
 207                for (i = 0; i < FSCK_MSG_MAX; i++)
 208                        msg_type[i] = fsck_msg_type(i, options);
 209                options->msg_type = msg_type;
 210        }
 211
 212        options->msg_type[id] = type;
 213}
 214
 215void fsck_set_msg_types(struct fsck_options *options, const char *values)
 216{
 217        char *buf = xstrdup(values), *to_free = buf;
 218        int done = 0;
 219
 220        while (!done) {
 221                int len = strcspn(buf, " ,|"), equal;
 222
 223                done = !buf[len];
 224                if (!len) {
 225                        buf++;
 226                        continue;
 227                }
 228                buf[len] = '\0';
 229
 230                for (equal = 0;
 231                     equal < len && buf[equal] != '=' && buf[equal] != ':';
 232                     equal++)
 233                        buf[equal] = tolower(buf[equal]);
 234                buf[equal] = '\0';
 235
 236                if (!strcmp(buf, "skiplist")) {
 237                        if (equal == len)
 238                                die("skiplist requires a path");
 239                        init_skiplist(options, buf + equal + 1);
 240                        buf += len + 1;
 241                        continue;
 242                }
 243
 244                if (equal == len)
 245                        die("Missing '=': '%s'", buf);
 246
 247                fsck_set_msg_type(options, buf, buf + equal + 1);
 248                buf += len + 1;
 249        }
 250        free(to_free);
 251}
 252
 253static void append_msg_id(struct strbuf *sb, const char *msg_id)
 254{
 255        for (;;) {
 256                char c = *(msg_id)++;
 257
 258                if (!c)
 259                        break;
 260                if (c != '_')
 261                        strbuf_addch(sb, tolower(c));
 262                else {
 263                        assert(*msg_id);
 264                        strbuf_addch(sb, *(msg_id)++);
 265                }
 266        }
 267
 268        strbuf_addstr(sb, ": ");
 269}
 270
 271__attribute__((format (printf, 4, 5)))
 272static int report(struct fsck_options *options, struct object *object,
 273        enum fsck_msg_id id, const char *fmt, ...)
 274{
 275        va_list ap;
 276        struct strbuf sb = STRBUF_INIT;
 277        int msg_type = fsck_msg_type(id, options), result;
 278
 279        if (msg_type == FSCK_IGNORE)
 280                return 0;
 281
 282        if (options->skiplist && object &&
 283                        oid_array_lookup(options->skiplist, &object->oid) >= 0)
 284                return 0;
 285
 286        if (msg_type == FSCK_FATAL)
 287                msg_type = FSCK_ERROR;
 288        else if (msg_type == FSCK_INFO)
 289                msg_type = FSCK_WARN;
 290
 291        append_msg_id(&sb, msg_id_info[id].id_string);
 292
 293        va_start(ap, fmt);
 294        strbuf_vaddf(&sb, fmt, ap);
 295        result = options->error_func(options, object, msg_type, sb.buf);
 296        strbuf_release(&sb);
 297        va_end(ap);
 298
 299        return result;
 300}
 301
 302static char *get_object_name(struct fsck_options *options, struct object *obj)
 303{
 304        if (!options->object_names)
 305                return NULL;
 306        return lookup_decoration(options->object_names, obj);
 307}
 308
 309static void put_object_name(struct fsck_options *options, struct object *obj,
 310        const char *fmt, ...)
 311{
 312        va_list ap;
 313        struct strbuf buf = STRBUF_INIT;
 314        char *existing;
 315
 316        if (!options->object_names)
 317                return;
 318        existing = lookup_decoration(options->object_names, obj);
 319        if (existing)
 320                return;
 321        va_start(ap, fmt);
 322        strbuf_vaddf(&buf, fmt, ap);
 323        add_decoration(options->object_names, obj, strbuf_detach(&buf, NULL));
 324        va_end(ap);
 325}
 326
 327static const char *describe_object(struct fsck_options *o, struct object *obj)
 328{
 329        static struct strbuf buf = STRBUF_INIT;
 330        char *name;
 331
 332        strbuf_reset(&buf);
 333        strbuf_addstr(&buf, oid_to_hex(&obj->oid));
 334        if (o->object_names && (name = lookup_decoration(o->object_names, obj)))
 335                strbuf_addf(&buf, " (%s)", name);
 336
 337        return buf.buf;
 338}
 339
 340static int fsck_walk_tree(struct tree *tree, void *data, struct fsck_options *options)
 341{
 342        struct tree_desc desc;
 343        struct name_entry entry;
 344        int res = 0;
 345        const char *name;
 346
 347        if (parse_tree(tree))
 348                return -1;
 349
 350        name = get_object_name(options, &tree->object);
 351        if (init_tree_desc_gently(&desc, tree->buffer, tree->size))
 352                return -1;
 353        while (tree_entry_gently(&desc, &entry)) {
 354                struct object *obj;
 355                int result;
 356
 357                if (S_ISGITLINK(entry.mode))
 358                        continue;
 359
 360                if (S_ISDIR(entry.mode)) {
 361                        obj = (struct object *)lookup_tree(entry.oid);
 362                        if (name && obj)
 363                                put_object_name(options, obj, "%s%s/", name,
 364                                        entry.path);
 365                        result = options->walk(obj, OBJ_TREE, data, options);
 366                }
 367                else if (S_ISREG(entry.mode) || S_ISLNK(entry.mode)) {
 368                        obj = (struct object *)lookup_blob(entry.oid);
 369                        if (name && obj)
 370                                put_object_name(options, obj, "%s%s", name,
 371                                        entry.path);
 372                        result = options->walk(obj, OBJ_BLOB, data, options);
 373                }
 374                else {
 375                        result = error("in tree %s: entry %s has bad mode %.6o",
 376                                        describe_object(options, &tree->object), entry.path, entry.mode);
 377                }
 378                if (result < 0)
 379                        return result;
 380                if (!res)
 381                        res = result;
 382        }
 383        return res;
 384}
 385
 386static int fsck_walk_commit(struct commit *commit, void *data, struct fsck_options *options)
 387{
 388        int counter = 0, generation = 0, name_prefix_len = 0;
 389        struct commit_list *parents;
 390        int res;
 391        int result;
 392        const char *name;
 393
 394        if (parse_commit(commit))
 395                return -1;
 396
 397        name = get_object_name(options, &commit->object);
 398        if (name)
 399                put_object_name(options, &commit->tree->object, "%s:", name);
 400
 401        result = options->walk((struct object *)commit->tree, OBJ_TREE, data, options);
 402        if (result < 0)
 403                return result;
 404        res = result;
 405
 406        parents = commit->parents;
 407        if (name && parents) {
 408                int len = strlen(name), power;
 409
 410                if (len && name[len - 1] == '^') {
 411                        generation = 1;
 412                        name_prefix_len = len - 1;
 413                }
 414                else { /* parse ~<generation> suffix */
 415                        for (generation = 0, power = 1;
 416                             len && isdigit(name[len - 1]);
 417                             power *= 10)
 418                                generation += power * (name[--len] - '0');
 419                        if (power > 1 && len && name[len - 1] == '~')
 420                                name_prefix_len = len - 1;
 421                }
 422        }
 423
 424        while (parents) {
 425                if (name) {
 426                        struct object *obj = &parents->item->object;
 427
 428                        if (++counter > 1)
 429                                put_object_name(options, obj, "%s^%d",
 430                                        name, counter);
 431                        else if (generation > 0)
 432                                put_object_name(options, obj, "%.*s~%d",
 433                                        name_prefix_len, name, generation + 1);
 434                        else
 435                                put_object_name(options, obj, "%s^", name);
 436                }
 437                result = options->walk((struct object *)parents->item, OBJ_COMMIT, data, options);
 438                if (result < 0)
 439                        return result;
 440                if (!res)
 441                        res = result;
 442                parents = parents->next;
 443        }
 444        return res;
 445}
 446
 447static int fsck_walk_tag(struct tag *tag, void *data, struct fsck_options *options)
 448{
 449        char *name = get_object_name(options, &tag->object);
 450
 451        if (parse_tag(tag))
 452                return -1;
 453        if (name)
 454                put_object_name(options, tag->tagged, "%s", name);
 455        return options->walk(tag->tagged, OBJ_ANY, data, options);
 456}
 457
 458int fsck_walk(struct object *obj, void *data, struct fsck_options *options)
 459{
 460        if (!obj)
 461                return -1;
 462
 463        if (obj->type == OBJ_NONE)
 464                parse_object(&obj->oid);
 465
 466        switch (obj->type) {
 467        case OBJ_BLOB:
 468                return 0;
 469        case OBJ_TREE:
 470                return fsck_walk_tree((struct tree *)obj, data, options);
 471        case OBJ_COMMIT:
 472                return fsck_walk_commit((struct commit *)obj, data, options);
 473        case OBJ_TAG:
 474                return fsck_walk_tag((struct tag *)obj, data, options);
 475        default:
 476                error("Unknown object type for %s", describe_object(options, obj));
 477                return -1;
 478        }
 479}
 480
 481/*
 482 * The entries in a tree are ordered in the _path_ order,
 483 * which means that a directory entry is ordered by adding
 484 * a slash to the end of it.
 485 *
 486 * So a directory called "a" is ordered _after_ a file
 487 * called "a.c", because "a/" sorts after "a.c".
 488 */
 489#define TREE_UNORDERED (-1)
 490#define TREE_HAS_DUPS  (-2)
 491
 492static int verify_ordered(unsigned mode1, const char *name1, unsigned mode2, const char *name2)
 493{
 494        int len1 = strlen(name1);
 495        int len2 = strlen(name2);
 496        int len = len1 < len2 ? len1 : len2;
 497        unsigned char c1, c2;
 498        int cmp;
 499
 500        cmp = memcmp(name1, name2, len);
 501        if (cmp < 0)
 502                return 0;
 503        if (cmp > 0)
 504                return TREE_UNORDERED;
 505
 506        /*
 507         * Ok, the first <len> characters are the same.
 508         * Now we need to order the next one, but turn
 509         * a '\0' into a '/' for a directory entry.
 510         */
 511        c1 = name1[len];
 512        c2 = name2[len];
 513        if (!c1 && !c2)
 514                /*
 515                 * git-write-tree used to write out a nonsense tree that has
 516                 * entries with the same name, one blob and one tree.  Make
 517                 * sure we do not have duplicate entries.
 518                 */
 519                return TREE_HAS_DUPS;
 520        if (!c1 && S_ISDIR(mode1))
 521                c1 = '/';
 522        if (!c2 && S_ISDIR(mode2))
 523                c2 = '/';
 524        return c1 < c2 ? 0 : TREE_UNORDERED;
 525}
 526
 527static int fsck_tree(struct tree *item, struct fsck_options *options)
 528{
 529        int retval = 0;
 530        int has_null_sha1 = 0;
 531        int has_full_path = 0;
 532        int has_empty_name = 0;
 533        int has_dot = 0;
 534        int has_dotdot = 0;
 535        int has_dotgit = 0;
 536        int has_zero_pad = 0;
 537        int has_bad_modes = 0;
 538        int has_dup_entries = 0;
 539        int not_properly_sorted = 0;
 540        struct tree_desc desc;
 541        unsigned o_mode;
 542        const char *o_name;
 543
 544        if (init_tree_desc_gently(&desc, item->buffer, item->size)) {
 545                retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
 546                return retval;
 547        }
 548
 549        o_mode = 0;
 550        o_name = NULL;
 551
 552        while (desc.size) {
 553                unsigned mode;
 554                const char *name;
 555                const struct object_id *oid;
 556
 557                oid = tree_entry_extract(&desc, &name, &mode);
 558
 559                has_null_sha1 |= is_null_oid(oid);
 560                has_full_path |= !!strchr(name, '/');
 561                has_empty_name |= !*name;
 562                has_dot |= !strcmp(name, ".");
 563                has_dotdot |= !strcmp(name, "..");
 564                has_dotgit |= is_hfs_dotgit(name) || is_ntfs_dotgit(name);
 565                has_zero_pad |= *(char *)desc.buffer == '0';
 566                if (update_tree_entry_gently(&desc)) {
 567                        retval += report(options, &item->object, FSCK_MSG_BAD_TREE, "cannot be parsed as a tree");
 568                        break;
 569                }
 570
 571                switch (mode) {
 572                /*
 573                 * Standard modes..
 574                 */
 575                case S_IFREG | 0755:
 576                case S_IFREG | 0644:
 577                case S_IFLNK:
 578                case S_IFDIR:
 579                case S_IFGITLINK:
 580                        break;
 581                /*
 582                 * This is nonstandard, but we had a few of these
 583                 * early on when we honored the full set of mode
 584                 * bits..
 585                 */
 586                case S_IFREG | 0664:
 587                        if (!options->strict)
 588                                break;
 589                        /* fallthrough */
 590                default:
 591                        has_bad_modes = 1;
 592                }
 593
 594                if (o_name) {
 595                        switch (verify_ordered(o_mode, o_name, mode, name)) {
 596                        case TREE_UNORDERED:
 597                                not_properly_sorted = 1;
 598                                break;
 599                        case TREE_HAS_DUPS:
 600                                has_dup_entries = 1;
 601                                break;
 602                        default:
 603                                break;
 604                        }
 605                }
 606
 607                o_mode = mode;
 608                o_name = name;
 609        }
 610
 611        if (has_null_sha1)
 612                retval += report(options, &item->object, FSCK_MSG_NULL_SHA1, "contains entries pointing to null sha1");
 613        if (has_full_path)
 614                retval += report(options, &item->object, FSCK_MSG_FULL_PATHNAME, "contains full pathnames");
 615        if (has_empty_name)
 616                retval += report(options, &item->object, FSCK_MSG_EMPTY_NAME, "contains empty pathname");
 617        if (has_dot)
 618                retval += report(options, &item->object, FSCK_MSG_HAS_DOT, "contains '.'");
 619        if (has_dotdot)
 620                retval += report(options, &item->object, FSCK_MSG_HAS_DOTDOT, "contains '..'");
 621        if (has_dotgit)
 622                retval += report(options, &item->object, FSCK_MSG_HAS_DOTGIT, "contains '.git'");
 623        if (has_zero_pad)
 624                retval += report(options, &item->object, FSCK_MSG_ZERO_PADDED_FILEMODE, "contains zero-padded file modes");
 625        if (has_bad_modes)
 626                retval += report(options, &item->object, FSCK_MSG_BAD_FILEMODE, "contains bad file modes");
 627        if (has_dup_entries)
 628                retval += report(options, &item->object, FSCK_MSG_DUPLICATE_ENTRIES, "contains duplicate file entries");
 629        if (not_properly_sorted)
 630                retval += report(options, &item->object, FSCK_MSG_TREE_NOT_SORTED, "not properly sorted");
 631        return retval;
 632}
 633
 634static int verify_headers(const void *data, unsigned long size,
 635                          struct object *obj, struct fsck_options *options)
 636{
 637        const char *buffer = (const char *)data;
 638        unsigned long i;
 639
 640        for (i = 0; i < size; i++) {
 641                switch (buffer[i]) {
 642                case '\0':
 643                        return report(options, obj,
 644                                FSCK_MSG_NUL_IN_HEADER,
 645                                "unterminated header: NUL at offset %ld", i);
 646                case '\n':
 647                        if (i + 1 < size && buffer[i + 1] == '\n')
 648                                return 0;
 649                }
 650        }
 651
 652        /*
 653         * We did not find double-LF that separates the header
 654         * and the body.  Not having a body is not a crime but
 655         * we do want to see the terminating LF for the last header
 656         * line.
 657         */
 658        if (size && buffer[size - 1] == '\n')
 659                return 0;
 660
 661        return report(options, obj,
 662                FSCK_MSG_UNTERMINATED_HEADER, "unterminated header");
 663}
 664
 665static int fsck_ident(const char **ident, struct object *obj, struct fsck_options *options)
 666{
 667        const char *p = *ident;
 668        char *end;
 669
 670        *ident = strchrnul(*ident, '\n');
 671        if (**ident == '\n')
 672                (*ident)++;
 673
 674        if (*p == '<')
 675                return report(options, obj, FSCK_MSG_MISSING_NAME_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 676        p += strcspn(p, "<>\n");
 677        if (*p == '>')
 678                return report(options, obj, FSCK_MSG_BAD_NAME, "invalid author/committer line - bad name");
 679        if (*p != '<')
 680                return report(options, obj, FSCK_MSG_MISSING_EMAIL, "invalid author/committer line - missing email");
 681        if (p[-1] != ' ')
 682                return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_EMAIL, "invalid author/committer line - missing space before email");
 683        p++;
 684        p += strcspn(p, "<>\n");
 685        if (*p != '>')
 686                return report(options, obj, FSCK_MSG_BAD_EMAIL, "invalid author/committer line - bad email");
 687        p++;
 688        if (*p != ' ')
 689                return report(options, obj, FSCK_MSG_MISSING_SPACE_BEFORE_DATE, "invalid author/committer line - missing space before date");
 690        p++;
 691        if (*p == '0' && p[1] != ' ')
 692                return report(options, obj, FSCK_MSG_ZERO_PADDED_DATE, "invalid author/committer line - zero-padded date");
 693        if (date_overflows(parse_timestamp(p, &end, 10)))
 694                return report(options, obj, FSCK_MSG_BAD_DATE_OVERFLOW, "invalid author/committer line - date causes integer overflow");
 695        if ((end == p || *end != ' '))
 696                return report(options, obj, FSCK_MSG_BAD_DATE, "invalid author/committer line - bad date");
 697        p = end + 1;
 698        if ((*p != '+' && *p != '-') ||
 699            !isdigit(p[1]) ||
 700            !isdigit(p[2]) ||
 701            !isdigit(p[3]) ||
 702            !isdigit(p[4]) ||
 703            (p[5] != '\n'))
 704                return report(options, obj, FSCK_MSG_BAD_TIMEZONE, "invalid author/committer line - bad time zone");
 705        p += 6;
 706        return 0;
 707}
 708
 709static int fsck_commit_buffer(struct commit *commit, const char *buffer,
 710        unsigned long size, struct fsck_options *options)
 711{
 712        unsigned char tree_sha1[20], sha1[20];
 713        struct commit_graft *graft;
 714        unsigned parent_count, parent_line_count = 0, author_count;
 715        int err;
 716        const char *buffer_begin = buffer;
 717
 718        if (verify_headers(buffer, size, &commit->object, options))
 719                return -1;
 720
 721        if (!skip_prefix(buffer, "tree ", &buffer))
 722                return report(options, &commit->object, FSCK_MSG_MISSING_TREE, "invalid format - expected 'tree' line");
 723        if (get_sha1_hex(buffer, tree_sha1) || buffer[40] != '\n') {
 724                err = report(options, &commit->object, FSCK_MSG_BAD_TREE_SHA1, "invalid 'tree' line format - bad sha1");
 725                if (err)
 726                        return err;
 727        }
 728        buffer += 41;
 729        while (skip_prefix(buffer, "parent ", &buffer)) {
 730                if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n') {
 731                        err = report(options, &commit->object, FSCK_MSG_BAD_PARENT_SHA1, "invalid 'parent' line format - bad sha1");
 732                        if (err)
 733                                return err;
 734                }
 735                buffer += 41;
 736                parent_line_count++;
 737        }
 738        graft = lookup_commit_graft(&commit->object.oid);
 739        parent_count = commit_list_count(commit->parents);
 740        if (graft) {
 741                if (graft->nr_parent == -1 && !parent_count)
 742                        ; /* shallow commit */
 743                else if (graft->nr_parent != parent_count) {
 744                        err = report(options, &commit->object, FSCK_MSG_MISSING_GRAFT, "graft objects missing");
 745                        if (err)
 746                                return err;
 747                }
 748        } else {
 749                if (parent_count != parent_line_count) {
 750                        err = report(options, &commit->object, FSCK_MSG_MISSING_PARENT, "parent objects missing");
 751                        if (err)
 752                                return err;
 753                }
 754        }
 755        author_count = 0;
 756        while (skip_prefix(buffer, "author ", &buffer)) {
 757                author_count++;
 758                err = fsck_ident(&buffer, &commit->object, options);
 759                if (err)
 760                        return err;
 761        }
 762        if (author_count < 1)
 763                err = report(options, &commit->object, FSCK_MSG_MISSING_AUTHOR, "invalid format - expected 'author' line");
 764        else if (author_count > 1)
 765                err = report(options, &commit->object, FSCK_MSG_MULTIPLE_AUTHORS, "invalid format - multiple 'author' lines");
 766        if (err)
 767                return err;
 768        if (!skip_prefix(buffer, "committer ", &buffer))
 769                return report(options, &commit->object, FSCK_MSG_MISSING_COMMITTER, "invalid format - expected 'committer' line");
 770        err = fsck_ident(&buffer, &commit->object, options);
 771        if (err)
 772                return err;
 773        if (!commit->tree) {
 774                err = report(options, &commit->object, FSCK_MSG_BAD_TREE, "could not load commit's tree %s", sha1_to_hex(tree_sha1));
 775                if (err)
 776                        return err;
 777        }
 778        if (memchr(buffer_begin, '\0', size)) {
 779                err = report(options, &commit->object, FSCK_MSG_NUL_IN_COMMIT,
 780                             "NUL byte in the commit object body");
 781                if (err)
 782                        return err;
 783        }
 784        return 0;
 785}
 786
 787static int fsck_commit(struct commit *commit, const char *data,
 788        unsigned long size, struct fsck_options *options)
 789{
 790        const char *buffer = data ?  data : get_commit_buffer(commit, &size);
 791        int ret = fsck_commit_buffer(commit, buffer, size, options);
 792        if (!data)
 793                unuse_commit_buffer(commit, buffer);
 794        return ret;
 795}
 796
 797static int fsck_tag_buffer(struct tag *tag, const char *data,
 798        unsigned long size, struct fsck_options *options)
 799{
 800        unsigned char sha1[20];
 801        int ret = 0;
 802        const char *buffer;
 803        char *to_free = NULL, *eol;
 804        struct strbuf sb = STRBUF_INIT;
 805
 806        if (data)
 807                buffer = data;
 808        else {
 809                enum object_type type;
 810
 811                buffer = to_free =
 812                        read_sha1_file(tag->object.oid.hash, &type, &size);
 813                if (!buffer)
 814                        return report(options, &tag->object,
 815                                FSCK_MSG_MISSING_TAG_OBJECT,
 816                                "cannot read tag object");
 817
 818                if (type != OBJ_TAG) {
 819                        ret = report(options, &tag->object,
 820                                FSCK_MSG_TAG_OBJECT_NOT_TAG,
 821                                "expected tag got %s",
 822                            type_name(type));
 823                        goto done;
 824                }
 825        }
 826
 827        ret = verify_headers(buffer, size, &tag->object, options);
 828        if (ret)
 829                goto done;
 830
 831        if (!skip_prefix(buffer, "object ", &buffer)) {
 832                ret = report(options, &tag->object, FSCK_MSG_MISSING_OBJECT, "invalid format - expected 'object' line");
 833                goto done;
 834        }
 835        if (get_sha1_hex(buffer, sha1) || buffer[40] != '\n') {
 836                ret = report(options, &tag->object, FSCK_MSG_BAD_OBJECT_SHA1, "invalid 'object' line format - bad sha1");
 837                if (ret)
 838                        goto done;
 839        }
 840        buffer += 41;
 841
 842        if (!skip_prefix(buffer, "type ", &buffer)) {
 843                ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE_ENTRY, "invalid format - expected 'type' line");
 844                goto done;
 845        }
 846        eol = strchr(buffer, '\n');
 847        if (!eol) {
 848                ret = report(options, &tag->object, FSCK_MSG_MISSING_TYPE, "invalid format - unexpected end after 'type' line");
 849                goto done;
 850        }
 851        if (type_from_string_gently(buffer, eol - buffer, 1) < 0)
 852                ret = report(options, &tag->object, FSCK_MSG_BAD_TYPE, "invalid 'type' value");
 853        if (ret)
 854                goto done;
 855        buffer = eol + 1;
 856
 857        if (!skip_prefix(buffer, "tag ", &buffer)) {
 858                ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG_ENTRY, "invalid format - expected 'tag' line");
 859                goto done;
 860        }
 861        eol = strchr(buffer, '\n');
 862        if (!eol) {
 863                ret = report(options, &tag->object, FSCK_MSG_MISSING_TAG, "invalid format - unexpected end after 'type' line");
 864                goto done;
 865        }
 866        strbuf_addf(&sb, "refs/tags/%.*s", (int)(eol - buffer), buffer);
 867        if (check_refname_format(sb.buf, 0)) {
 868                ret = report(options, &tag->object, FSCK_MSG_BAD_TAG_NAME,
 869                           "invalid 'tag' name: %.*s",
 870                           (int)(eol - buffer), buffer);
 871                if (ret)
 872                        goto done;
 873        }
 874        buffer = eol + 1;
 875
 876        if (!skip_prefix(buffer, "tagger ", &buffer)) {
 877                /* early tags do not contain 'tagger' lines; warn only */
 878                ret = report(options, &tag->object, FSCK_MSG_MISSING_TAGGER_ENTRY, "invalid format - expected 'tagger' line");
 879                if (ret)
 880                        goto done;
 881        }
 882        else
 883                ret = fsck_ident(&buffer, &tag->object, options);
 884
 885done:
 886        strbuf_release(&sb);
 887        free(to_free);
 888        return ret;
 889}
 890
 891static int fsck_tag(struct tag *tag, const char *data,
 892        unsigned long size, struct fsck_options *options)
 893{
 894        struct object *tagged = tag->tagged;
 895
 896        if (!tagged)
 897                return report(options, &tag->object, FSCK_MSG_BAD_TAG_OBJECT, "could not load tagged object");
 898
 899        return fsck_tag_buffer(tag, data, size, options);
 900}
 901
 902static int fsck_blob(struct blob *blob, const char *buf,
 903                     unsigned long size, struct fsck_options *options)
 904{
 905        return 0;
 906}
 907
 908int fsck_object(struct object *obj, void *data, unsigned long size,
 909        struct fsck_options *options)
 910{
 911        if (!obj)
 912                return report(options, obj, FSCK_MSG_BAD_OBJECT_SHA1, "no valid object to fsck");
 913
 914        if (obj->type == OBJ_BLOB)
 915                return fsck_blob((struct blob *)obj, data, size, options);
 916        if (obj->type == OBJ_TREE)
 917                return fsck_tree((struct tree *) obj, options);
 918        if (obj->type == OBJ_COMMIT)
 919                return fsck_commit((struct commit *) obj, (const char *) data,
 920                        size, options);
 921        if (obj->type == OBJ_TAG)
 922                return fsck_tag((struct tag *) obj, (const char *) data,
 923                        size, options);
 924
 925        return report(options, obj, FSCK_MSG_UNKNOWN_TYPE, "unknown type '%d' (internal fsck error)",
 926                          obj->type);
 927}
 928
 929int fsck_error_function(struct fsck_options *o,
 930        struct object *obj, int msg_type, const char *message)
 931{
 932        if (msg_type == FSCK_WARN) {
 933                warning("object %s: %s", describe_object(o, obj), message);
 934                return 0;
 935        }
 936        error("object %s: %s", describe_object(o, obj), message);
 937        return 1;
 938}