read-cache.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6 #define NO_THE_INDEX_COMPATIBILITY_MACROS
   7 #include "cache.h"
   8 #include "cache-tree.h"
   9 #include "refs.h"
  10 #include "dir.h"
  11
  12 /* Index extensions.
  13  *
  14  * The first letter should be 'A'..'Z' for extensions that are not
  15  * necessary for a correct operation (i.e. optimization data).
  16  * When new extensions are added that _needs_ to be understood in
  17  * order to correctly interpret the index file, pick character that
  18  * is outside the range, to cause the reader to abort.
  19  */
  20
  21 #define CACHE_EXT(s) ( (s[0]<<24)|(s[1]<<16)|(s[2]<<8)|(s[3]) )
  22 #define CACHE_EXT_TREE 0x54524545       /* "TREE" */
  23
  24 struct index_state the_index;
  25
  26 static unsigned int hash_name(const char *name, int namelen)
  27 {
  28         unsigned int hash = 0x123;
  29
  30         do {
  31                 unsigned char c = *name++;
  32                 hash = hash*101 + c;
  33         } while (--namelen);
  34         return hash;
  35 }
  36
  37 static void hash_index_entry(struct index_state *istate, struct cache_entry *ce)
  38 {
  39         void **pos;
  40         unsigned int hash;
  41
  42         if (ce->ce_flags & CE_HASHED)
  43                 return;
  44         ce->ce_flags |= CE_HASHED;
  45         ce->next = NULL;
  46         hash = hash_name(ce->name, ce_namelen(ce));
  47         pos = insert_hash(hash, ce, &istate->name_hash);
  48         if (pos) {
  49                 ce->next = *pos;
  50                 *pos = ce;
  51         }
  52 }
  53
  54 static void lazy_init_name_hash(struct index_state *istate)
  55 {
  56         int nr;
  57
  58         if (istate->name_hash_initialized)
  59                 return;
  60         for (nr = 0; nr < istate->cache_nr; nr++)
  61                 hash_index_entry(istate, istate->cache[nr]);
  62         istate->name_hash_initialized = 1;
  63 }
  64
  65 static void set_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
  66 {
  67         ce->ce_flags &= ~CE_UNHASHED;
  68         istate->cache[nr] = ce;
  69         if (istate->name_hash_initialized)
  70                 hash_index_entry(istate, ce);
  71 }
  72
  73 static void replace_index_entry(struct index_state *istate, int nr, struct cache_entry *ce)
  74 {
  75         struct cache_entry *old = istate->cache[nr];
  76
  77         remove_index_entry(old);
  78         set_index_entry(istate, nr, ce);
  79         istate->cache_changed = 1;
  80 }
  81
  82 int index_name_exists(struct index_state *istate, const char *name, int namelen)
  83 {
  84         unsigned int hash = hash_name(name, namelen);
  85         struct cache_entry *ce;
  86
  87         lazy_init_name_hash(istate);
  88         ce = lookup_hash(hash, &istate->name_hash);
  89
  90         while (ce) {
  91                 if (!(ce->ce_flags & CE_UNHASHED)) {
  92                         if (!cache_name_compare(name, namelen, ce->name, ce->ce_flags))
  93                                 return 1;
  94                 }
  95                 ce = ce->next;
  96         }
  97         return 0;
  98 }
  99
 100 /*
 101  * This only updates the "non-critical" parts of the directory
 102  * cache, ie the parts that aren't tracked by GIT, and only used
 103  * to validate the cache.
 104  */
 105 void fill_stat_cache_info(struct cache_entry *ce, struct stat *st)
 106 {
 107         ce->ce_ctime = st->st_ctime;
 108         ce->ce_mtime = st->st_mtime;
 109         ce->ce_dev = st->st_dev;
 110         ce->ce_ino = st->st_ino;
 111         ce->ce_uid = st->st_uid;
 112         ce->ce_gid = st->st_gid;
 113         ce->ce_size = st->st_size;
 114
 115         if (assume_unchanged)
 116                 ce->ce_flags |= CE_VALID;
 117
 118         if (S_ISREG(st->st_mode))
 119                 ce_mark_uptodate(ce);
 120 }
 121
 122 static int ce_compare_data(struct cache_entry *ce, struct stat *st)
 123 {
 124         int match = -1;
 125         int fd = open(ce->name, O_RDONLY);
 126
 127         if (fd >= 0) {
 128                 unsigned char sha1[20];
 129                 if (!index_fd(sha1, fd, st, 0, OBJ_BLOB, ce->name))
 130                         match = hashcmp(sha1, ce->sha1);
 131                 /* index_fd() closed the file descriptor already */
 132         }
 133         return match;
 134 }
 135
 136 static int ce_compare_link(struct cache_entry *ce, size_t expected_size)
 137 {
 138         int match = -1;
 139         char *target;
 140         void *buffer;
 141         unsigned long size;
 142         enum object_type type;
 143         int len;
 144
 145         target = xmalloc(expected_size);
 146         len = readlink(ce->name, target, expected_size);
 147         if (len != expected_size) {
 148                 free(target);
 149                 return -1;
 150         }
 151         buffer = read_sha1_file(ce->sha1, &type, &size);
 152         if (!buffer) {
 153                 free(target);
 154                 return -1;
 155         }
 156         if (size == expected_size)
 157                 match = memcmp(buffer, target, size);
 158         free(buffer);
 159         free(target);
 160         return match;
 161 }
 162
 163 static int ce_compare_gitlink(struct cache_entry *ce)
 164 {
 165         unsigned char sha1[20];
 166
 167         /*
 168          * We don't actually require that the .git directory
 169          * under GITLINK directory be a valid git directory. It
 170          * might even be missing (in case nobody populated that
 171          * sub-project).
 172          *
 173          * If so, we consider it always to match.
 174          */
 175         if (resolve_gitlink_ref(ce->name, "HEAD", sha1) < 0)
 176                 return 0;
 177         return hashcmp(sha1, ce->sha1);
 178 }
 179
 180 static int ce_modified_check_fs(struct cache_entry *ce, struct stat *st)
 181 {
 182         switch (st->st_mode & S_IFMT) {
 183         case S_IFREG:
 184                 if (ce_compare_data(ce, st))
 185                         return DATA_CHANGED;
 186                 break;
 187         case S_IFLNK:
 188                 if (ce_compare_link(ce, xsize_t(st->st_size)))
 189                         return DATA_CHANGED;
 190                 break;
 191         case S_IFDIR:
 192                 if (S_ISGITLINK(ce->ce_mode))
 193                         return 0;
 194         default:
 195                 return TYPE_CHANGED;
 196         }
 197         return 0;
 198 }
 199
 200 static int is_empty_blob_sha1(const unsigned char *sha1)
 201 {
 202         static const unsigned char empty_blob_sha1[20] = {
 203                 0xe6,0x9d,0xe2,0x9b,0xb2,0xd1,0xd6,0x43,0x4b,0x8b,
 204                 0x29,0xae,0x77,0x5a,0xd8,0xc2,0xe4,0x8c,0x53,0x91
 205         };
 206
 207         return !hashcmp(sha1, empty_blob_sha1);
 208 }
 209
 210 static int ce_match_stat_basic(struct cache_entry *ce, struct stat *st)
 211 {
 212         unsigned int changed = 0;
 213
 214         if (ce->ce_flags & CE_REMOVE)
 215                 return MODE_CHANGED | DATA_CHANGED | TYPE_CHANGED;
 216
 217         switch (ce->ce_mode & S_IFMT) {
 218         case S_IFREG:
 219                 changed |= !S_ISREG(st->st_mode) ? TYPE_CHANGED : 0;
 220                 /* We consider only the owner x bit to be relevant for
 221                  * "mode changes"
 222                  */
 223                 if (trust_executable_bit &&
 224                     (0100 & (ce->ce_mode ^ st->st_mode)))
 225                         changed |= MODE_CHANGED;
 226                 break;
 227         case S_IFLNK:
 228                 if (!S_ISLNK(st->st_mode) &&
 229                     (has_symlinks || !S_ISREG(st->st_mode)))
 230                         changed |= TYPE_CHANGED;
 231                 break;
 232         case S_IFGITLINK:
 233                 if (!S_ISDIR(st->st_mode))
 234                         changed |= TYPE_CHANGED;
 235                 else if (ce_compare_gitlink(ce))
 236                         changed |= DATA_CHANGED;
 237                 return changed;
 238         default:
 239                 die("internal error: ce_mode is %o", ce->ce_mode);
 240         }
 241         if (ce->ce_mtime != (unsigned int) st->st_mtime)
 242                 changed |= MTIME_CHANGED;
 243         if (ce->ce_ctime != (unsigned int) st->st_ctime)
 244                 changed |= CTIME_CHANGED;
 245
 246         if (ce->ce_uid != (unsigned int) st->st_uid ||
 247             ce->ce_gid != (unsigned int) st->st_gid)
 248                 changed |= OWNER_CHANGED;
 249         if (ce->ce_ino != (unsigned int) st->st_ino)
 250                 changed |= INODE_CHANGED;
 251
 252 #ifdef USE_STDEV
 253         /*
 254          * st_dev breaks on network filesystems where different
 255          * clients will have different views of what "device"
 256          * the filesystem is on
 257          */
 258         if (ce->ce_dev != (unsigned int) st->st_dev)
 259                 changed |= INODE_CHANGED;
 260 #endif
 261
 262         if (ce->ce_size != (unsigned int) st->st_size)
 263                 changed |= DATA_CHANGED;
 264
 265         /* Racily smudged entry? */
 266         if (!ce->ce_size) {
 267                 if (!is_empty_blob_sha1(ce->sha1))
 268                         changed |= DATA_CHANGED;
 269         }
 270
 271         return changed;
 272 }
 273
 274 static int is_racy_timestamp(const struct index_state *istate, struct cache_entry *ce)
 275 {
 276         return (istate->timestamp &&
 277                 ((unsigned int)istate->timestamp) <= ce->ce_mtime);
 278 }
 279
 280 int ie_match_stat(const struct index_state *istate,
 281                   struct cache_entry *ce, struct stat *st,
 282                   unsigned int options)
 283 {
 284         unsigned int changed;
 285         int ignore_valid = options & CE_MATCH_IGNORE_VALID;
 286         int assume_racy_is_modified = options & CE_MATCH_RACY_IS_DIRTY;
 287
 288         /*
 289          * If it's marked as always valid in the index, it's
 290          * valid whatever the checked-out copy says.
 291          */
 292         if (!ignore_valid && (ce->ce_flags & CE_VALID))
 293                 return 0;
 294
 295         changed = ce_match_stat_basic(ce, st);
 296
 297         /*
 298          * Within 1 second of this sequence:
 299          *      echo xyzzy >file && git-update-index --add file
 300          * running this command:
 301          *      echo frotz >file
 302          * would give a falsely clean cache entry.  The mtime and
 303          * length match the cache, and other stat fields do not change.
 304          *
 305          * We could detect this at update-index time (the cache entry
 306          * being registered/updated records the same time as "now")
 307          * and delay the return from git-update-index, but that would
 308          * effectively mean we can make at most one commit per second,
 309          * which is not acceptable.  Instead, we check cache entries
 310          * whose mtime are the same as the index file timestamp more
 311          * carefully than others.
 312          */
 313         if (!changed && is_racy_timestamp(istate, ce)) {
 314                 if (assume_racy_is_modified)
 315                         changed |= DATA_CHANGED;
 316                 else
 317                         changed |= ce_modified_check_fs(ce, st);
 318         }
 319
 320         return changed;
 321 }
 322
 323 int ie_modified(const struct index_state *istate,
 324                 struct cache_entry *ce, struct stat *st, unsigned int options)
 325 {
 326         int changed, changed_fs;
 327
 328         changed = ie_match_stat(istate, ce, st, options);
 329         if (!changed)
 330                 return 0;
 331         /*
 332          * If the mode or type has changed, there's no point in trying
 333          * to refresh the entry - it's not going to match
 334          */
 335         if (changed & (MODE_CHANGED | TYPE_CHANGED))
 336                 return changed;
 337
 338         /* Immediately after read-tree or update-index --cacheinfo,
 339          * the length field is zero.  For other cases the ce_size
 340          * should match the SHA1 recorded in the index entry.
 341          */
 342         if ((changed & DATA_CHANGED) && ce->ce_size != 0)
 343                 return changed;
 344
 345         changed_fs = ce_modified_check_fs(ce, st);
 346         if (changed_fs)
 347                 return changed | changed_fs;
 348         return 0;
 349 }
 350
 351 int base_name_compare(const char *name1, int len1, int mode1,
 352                       const char *name2, int len2, int mode2)
 353 {
 354         unsigned char c1, c2;
 355         int len = len1 < len2 ? len1 : len2;
 356         int cmp;
 357
 358         cmp = memcmp(name1, name2, len);
 359         if (cmp)
 360                 return cmp;
 361         c1 = name1[len];
 362         c2 = name2[len];
 363         if (!c1 && S_ISDIR(mode1))
 364                 c1 = '/';
 365         if (!c2 && S_ISDIR(mode2))
 366                 c2 = '/';
 367         return (c1 < c2) ? -1 : (c1 > c2) ? 1 : 0;
 368 }
 369
 370 /*
 371  * df_name_compare() is identical to base_name_compare(), except it
 372  * compares conflicting directory/file entries as equal. Note that
 373  * while a directory name compares as equal to a regular file, they
 374  * then individually compare _differently_ to a filename that has
 375  * a dot after the basename (because '\0' < '.' < '/').
 376  *
 377  * This is used by routines that want to traverse the git namespace
 378  * but then handle conflicting entries together when possible.
 379  */
 380 int df_name_compare(const char *name1, int len1, int mode1,
 381                     const char *name2, int len2, int mode2)
 382 {
 383         int len = len1 < len2 ? len1 : len2, cmp;
 384         unsigned char c1, c2;
 385
 386         cmp = memcmp(name1, name2, len);
 387         if (cmp)
 388                 return cmp;
 389         /* Directories and files compare equal (same length, same name) */
 390         if (len1 == len2)
 391                 return 0;
 392         c1 = name1[len];
 393         if (!c1 && S_ISDIR(mode1))
 394                 c1 = '/';
 395         c2 = name2[len];
 396         if (!c2 && S_ISDIR(mode2))
 397                 c2 = '/';
 398         if (c1 == '/' && !c2)
 399                 return 0;
 400         if (c2 == '/' && !c1)
 401                 return 0;
 402         return c1 - c2;
 403 }
 404
 405 int cache_name_compare(const char *name1, int flags1, const char *name2, int flags2)
 406 {
 407         int len1 = flags1 & CE_NAMEMASK;
 408         int len2 = flags2 & CE_NAMEMASK;
 409         int len = len1 < len2 ? len1 : len2;
 410         int cmp;
 411
 412         cmp = memcmp(name1, name2, len);
 413         if (cmp)
 414                 return cmp;
 415         if (len1 < len2)
 416                 return -1;
 417         if (len1 > len2)
 418                 return 1;
 419
 420         /* Compare stages  */
 421         flags1 &= CE_STAGEMASK;
 422         flags2 &= CE_STAGEMASK;
 423
 424         if (flags1 < flags2)
 425                 return -1;
 426         if (flags1 > flags2)
 427                 return 1;
 428         return 0;
 429 }
 430
 431 int index_name_pos(const struct index_state *istate, const char *name, int namelen)
 432 {
 433         int first, last;
 434
 435         first = 0;
 436         last = istate->cache_nr;
 437         while (last > first) {
 438                 int next = (last + first) >> 1;
 439                 struct cache_entry *ce = istate->cache[next];
 440                 int cmp = cache_name_compare(name, namelen, ce->name, ce->ce_flags);
 441                 if (!cmp)
 442                         return next;
 443                 if (cmp < 0) {
 444                         last = next;
 445                         continue;
 446                 }
 447                 first = next+1;
 448         }
 449         return -first-1;
 450 }
 451
 452 /* Remove entry, return true if there are more entries to go.. */
 453 int remove_index_entry_at(struct index_state *istate, int pos)
 454 {
 455         struct cache_entry *ce = istate->cache[pos];
 456
 457         remove_index_entry(ce);
 458         istate->cache_changed = 1;
 459         istate->cache_nr--;
 460         if (pos >= istate->cache_nr)
 461                 return 0;
 462         memmove(istate->cache + pos,
 463                 istate->cache + pos + 1,
 464                 (istate->cache_nr - pos) * sizeof(struct cache_entry *));
 465         return 1;
 466 }
 467
 468 int remove_file_from_index(struct index_state *istate, const char *path)
 469 {
 470         int pos = index_name_pos(istate, path, strlen(path));
 471         if (pos < 0)
 472                 pos = -pos-1;
 473         cache_tree_invalidate_path(istate->cache_tree, path);
 474         while (pos < istate->cache_nr && !strcmp(istate->cache[pos]->name, path))
 475                 remove_index_entry_at(istate, pos);
 476         return 0;
 477 }
 478
 479 static int compare_name(struct cache_entry *ce, const char *path, int namelen)
 480 {
 481         return namelen != ce_namelen(ce) || memcmp(path, ce->name, namelen);
 482 }
 483
 484 static int index_name_pos_also_unmerged(struct index_state *istate,
 485         const char *path, int namelen)
 486 {
 487         int pos = index_name_pos(istate, path, namelen);
 488         struct cache_entry *ce;
 489
 490         if (pos >= 0)
 491                 return pos;
 492
 493         /* maybe unmerged? */
 494         pos = -1 - pos;
 495         if (pos >= istate->cache_nr ||
 496                         compare_name((ce = istate->cache[pos]), path, namelen))
 497                 return -1;
 498
 499         /* order of preference: stage 2, 1, 3 */
 500         if (ce_stage(ce) == 1 && pos + 1 < istate->cache_nr &&
 501                         ce_stage((ce = istate->cache[pos + 1])) == 2 &&
 502                         !compare_name(ce, path, namelen))
 503                 pos++;
 504         return pos;
 505 }
 506
 507 int add_file_to_index(struct index_state *istate, const char *path, int verbose)
 508 {
 509         int size, namelen, pos;
 510         struct stat st;
 511         struct cache_entry *ce;
 512         unsigned ce_option = CE_MATCH_IGNORE_VALID|CE_MATCH_RACY_IS_DIRTY;
 513
 514         if (lstat(path, &st))
 515                 die("%s: unable to stat (%s)", path, strerror(errno));
 516
 517         if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode) && !S_ISDIR(st.st_mode))
 518                 die("%s: can only add regular files, symbolic links or git-directories", path);
 519
 520         namelen = strlen(path);
 521         if (S_ISDIR(st.st_mode)) {
 522                 while (namelen && path[namelen-1] == '/')
 523                         namelen--;
 524         }
 525         size = cache_entry_size(namelen);
 526         ce = xcalloc(1, size);
 527         memcpy(ce->name, path, namelen);
 528         ce->ce_flags = namelen;
 529         fill_stat_cache_info(ce, &st);
 530
 531         if (trust_executable_bit && has_symlinks)
 532                 ce->ce_mode = create_ce_mode(st.st_mode);
 533         else {
 534                 /* If there is an existing entry, pick the mode bits and type
 535                  * from it, otherwise assume unexecutable regular file.
 536                  */
 537                 struct cache_entry *ent;
 538                 int pos = index_name_pos_also_unmerged(istate, path, namelen);
 539
 540                 ent = (0 <= pos) ? istate->cache[pos] : NULL;
 541                 ce->ce_mode = ce_mode_from_stat(ent, st.st_mode);
 542         }
 543
 544         pos = index_name_pos(istate, ce->name, namelen);
 545         if (0 <= pos &&
 546             !ce_stage(istate->cache[pos]) &&
 547             !ie_match_stat(istate, istate->cache[pos], &st, ce_option)) {
 548                 /* Nothing changed, really */
 549                 free(ce);
 550                 ce_mark_uptodate(istate->cache[pos]);
 551                 return 0;
 552         }
 553
 554         if (index_path(ce->sha1, path, &st, 1))
 555                 die("unable to index file %s", path);
 556         if (add_index_entry(istate, ce, ADD_CACHE_OK_TO_ADD|ADD_CACHE_OK_TO_REPLACE))
 557                 die("unable to add %s to index",path);
 558         if (verbose)
 559                 printf("add '%s'\n", path);
 560         return 0;
 561 }
 562
 563 struct cache_entry *make_cache_entry(unsigned int mode,
 564                 const unsigned char *sha1, const char *path, int stage,
 565                 int refresh)
 566 {
 567         int size, len;
 568         struct cache_entry *ce;
 569
 570         if (!verify_path(path))
 571                 return NULL;
 572
 573         len = strlen(path);
 574         size = cache_entry_size(len);
 575         ce = xcalloc(1, size);
 576
 577         hashcpy(ce->sha1, sha1);
 578         memcpy(ce->name, path, len);
 579         ce->ce_flags = create_ce_flags(len, stage);
 580         ce->ce_mode = create_ce_mode(mode);
 581
 582         if (refresh)
 583                 return refresh_cache_entry(ce, 0);
 584
 585         return ce;
 586 }
 587
 588 int ce_same_name(struct cache_entry *a, struct cache_entry *b)
 589 {
 590         int len = ce_namelen(a);
 591         return ce_namelen(b) == len && !memcmp(a->name, b->name, len);
 592 }
 593
 594 int ce_path_match(const struct cache_entry *ce, const char **pathspec)
 595 {
 596         const char *match, *name;
 597         int len;
 598
 599         if (!pathspec)
 600                 return 1;
 601
 602         len = ce_namelen(ce);
 603         name = ce->name;
 604         while ((match = *pathspec++) != NULL) {
 605                 int matchlen = strlen(match);
 606                 if (matchlen > len)
 607                         continue;
 608                 if (memcmp(name, match, matchlen))
 609                         continue;
 610                 if (matchlen && name[matchlen-1] == '/')
 611                         return 1;
 612                 if (name[matchlen] == '/' || !name[matchlen])
 613                         return 1;
 614                 if (!matchlen)
 615                         return 1;
 616         }
 617         return 0;
 618 }
 619
 620 /*
 621  * We fundamentally don't like some paths: we don't want
 622  * dot or dot-dot anywhere, and for obvious reasons don't
 623  * want to recurse into ".git" either.
 624  *
 625  * Also, we don't want double slashes or slashes at the
 626  * end that can make pathnames ambiguous.
 627  */
 628 static int verify_dotfile(const char *rest)
 629 {
 630         /*
 631          * The first character was '.', but that
 632          * has already been discarded, we now test
 633          * the rest.
 634          */
 635         switch (*rest) {
 636         /* "." is not allowed */
 637         case '\0': case '/':
 638                 return 0;
 639
 640         /*
 641          * ".git" followed by  NUL or slash is bad. This
 642          * shares the path end test with the ".." case.
 643          */
 644         case 'g':
 645                 if (rest[1] != 'i')
 646                         break;
 647                 if (rest[2] != 't')
 648                         break;
 649                 rest += 2;
 650         /* fallthrough */
 651         case '.':
 652                 if (rest[1] == '\0' || rest[1] == '/')
 653                         return 0;
 654         }
 655         return 1;
 656 }
 657
 658 int verify_path(const char *path)
 659 {
 660         char c;
 661
 662         goto inside;
 663         for (;;) {
 664                 if (!c)
 665                         return 1;
 666                 if (c == '/') {
 667 inside:
 668                         c = *path++;
 669                         switch (c) {
 670                         default:
 671                                 continue;
 672                         case '/': case '\0':
 673                                 break;
 674                         case '.':
 675                                 if (verify_dotfile(path))
 676                                         continue;
 677                         }
 678                         return 0;
 679                 }
 680                 c = *path++;
 681         }
 682 }
 683
 684 /*
 685  * Do we have another file that has the beginning components being a
 686  * proper superset of the name we're trying to add?
 687  */
 688 static int has_file_name(struct index_state *istate,
 689                          const struct cache_entry *ce, int pos, int ok_to_replace)
 690 {
 691         int retval = 0;
 692         int len = ce_namelen(ce);
 693         int stage = ce_stage(ce);
 694         const char *name = ce->name;
 695
 696         while (pos < istate->cache_nr) {
 697                 struct cache_entry *p = istate->cache[pos++];
 698
 699                 if (len >= ce_namelen(p))
 700                         break;
 701                 if (memcmp(name, p->name, len))
 702                         break;
 703                 if (ce_stage(p) != stage)
 704                         continue;
 705                 if (p->name[len] != '/')
 706                         continue;
 707                 if (p->ce_flags & CE_REMOVE)
 708                         continue;
 709                 retval = -1;
 710                 if (!ok_to_replace)
 711                         break;
 712                 remove_index_entry_at(istate, --pos);
 713         }
 714         return retval;
 715 }
 716
 717 /*
 718  * Do we have another file with a pathname that is a proper
 719  * subset of the name we're trying to add?
 720  */
 721 static int has_dir_name(struct index_state *istate,
 722                         const struct cache_entry *ce, int pos, int ok_to_replace)
 723 {
 724         int retval = 0;
 725         int stage = ce_stage(ce);
 726         const char *name = ce->name;
 727         const char *slash = name + ce_namelen(ce);
 728
 729         for (;;) {
 730                 int len;
 731
 732                 for (;;) {
 733                         if (*--slash == '/')
 734                                 break;
 735                         if (slash <= ce->name)
 736                                 return retval;
 737                 }
 738                 len = slash - name;
 739
 740                 pos = index_name_pos(istate, name, create_ce_flags(len, stage));
 741                 if (pos >= 0) {
 742                         /*
 743                          * Found one, but not so fast.  This could
 744                          * be a marker that says "I was here, but
 745                          * I am being removed".  Such an entry is
 746                          * not a part of the resulting tree, and
 747                          * it is Ok to have a directory at the same
 748                          * path.
 749                          */
 750                         if (!(istate->cache[pos]->ce_flags & CE_REMOVE)) {
 751                                 retval = -1;
 752                                 if (!ok_to_replace)
 753                                         break;
 754                                 remove_index_entry_at(istate, pos);
 755                                 continue;
 756                         }
 757                 }
 758                 else
 759                         pos = -pos-1;
 760
 761                 /*
 762                  * Trivial optimization: if we find an entry that
 763                  * already matches the sub-directory, then we know
 764                  * we're ok, and we can exit.
 765                  */
 766                 while (pos < istate->cache_nr) {
 767                         struct cache_entry *p = istate->cache[pos];
 768                         if ((ce_namelen(p) <= len) ||
 769                             (p->name[len] != '/') ||
 770                             memcmp(p->name, name, len))
 771                                 break; /* not our subdirectory */
 772                         if (ce_stage(p) == stage && !(p->ce_flags & CE_REMOVE))
 773                                 /*
 774                                  * p is at the same stage as our entry, and
 775                                  * is a subdirectory of what we are looking
 776                                  * at, so we cannot have conflicts at our
 777                                  * level or anything shorter.
 778                                  */
 779                                 return retval;
 780                         pos++;
 781                 }
 782         }
 783         return retval;
 784 }
 785
 786 /* We may be in a situation where we already have path/file and path
 787  * is being added, or we already have path and path/file is being
 788  * added.  Either one would result in a nonsense tree that has path
 789  * twice when git-write-tree tries to write it out.  Prevent it.
 790  *
 791  * If ok-to-replace is specified, we remove the conflicting entries
 792  * from the cache so the caller should recompute the insert position.
 793  * When this happens, we return non-zero.
 794  */
 795 static int check_file_directory_conflict(struct index_state *istate,
 796                                          const struct cache_entry *ce,
 797                                          int pos, int ok_to_replace)
 798 {
 799         int retval;
 800
 801         /*
 802          * When ce is an "I am going away" entry, we allow it to be added
 803          */
 804         if (ce->ce_flags & CE_REMOVE)
 805                 return 0;
 806
 807         /*
 808          * We check if the path is a sub-path of a subsequent pathname
 809          * first, since removing those will not change the position
 810          * in the array.
 811          */
 812         retval = has_file_name(istate, ce, pos, ok_to_replace);
 813
 814         /*
 815          * Then check if the path might have a clashing sub-directory
 816          * before it.
 817          */
 818         return retval + has_dir_name(istate, ce, pos, ok_to_replace);
 819 }
 820
 821 static int add_index_entry_with_check(struct index_state *istate, struct cache_entry *ce, int option)
 822 {
 823         int pos;
 824         int ok_to_add = option & ADD_CACHE_OK_TO_ADD;
 825         int ok_to_replace = option & ADD_CACHE_OK_TO_REPLACE;
 826         int skip_df_check = option & ADD_CACHE_SKIP_DFCHECK;
 827
 828         cache_tree_invalidate_path(istate->cache_tree, ce->name);
 829         pos = index_name_pos(istate, ce->name, ce->ce_flags);
 830
 831         /* existing match? Just replace it. */
 832         if (pos >= 0) {
 833                 replace_index_entry(istate, pos, ce);
 834                 return 0;
 835         }
 836         pos = -pos-1;
 837
 838         /*
 839          * Inserting a merged entry ("stage 0") into the index
 840          * will always replace all non-merged entries..
 841          */
 842         if (pos < istate->cache_nr && ce_stage(ce) == 0) {
 843                 while (ce_same_name(istate->cache[pos], ce)) {
 844                         ok_to_add = 1;
 845                         if (!remove_index_entry_at(istate, pos))
 846                                 break;
 847                 }
 848         }
 849
 850         if (!ok_to_add)
 851                 return -1;
 852         if (!verify_path(ce->name))
 853                 return -1;
 854
 855         if (!skip_df_check &&
 856             check_file_directory_conflict(istate, ce, pos, ok_to_replace)) {
 857                 if (!ok_to_replace)
 858                         return error("'%s' appears as both a file and as a directory",
 859                                      ce->name);
 860                 pos = index_name_pos(istate, ce->name, ce->ce_flags);
 861                 pos = -pos-1;
 862         }
 863         return pos + 1;
 864 }
 865
 866 int add_index_entry(struct index_state *istate, struct cache_entry *ce, int option)
 867 {
 868         int pos;
 869
 870         if (option & ADD_CACHE_JUST_APPEND)
 871                 pos = istate->cache_nr;
 872         else {
 873                 int ret;
 874                 ret = add_index_entry_with_check(istate, ce, option);
 875                 if (ret <= 0)
 876                         return ret;
 877                 pos = ret - 1;
 878         }
 879
 880         /* Make sure the array is big enough .. */
 881         if (istate->cache_nr == istate->cache_alloc) {
 882                 istate->cache_alloc = alloc_nr(istate->cache_alloc);
 883                 istate->cache = xrealloc(istate->cache,
 884                                         istate->cache_alloc * sizeof(struct cache_entry *));
 885         }
 886
 887         /* Add it in.. */
 888         istate->cache_nr++;
 889         if (istate->cache_nr > pos + 1)
 890                 memmove(istate->cache + pos + 1,
 891                         istate->cache + pos,
 892                         (istate->cache_nr - pos - 1) * sizeof(ce));
 893         set_index_entry(istate, pos, ce);
 894         istate->cache_changed = 1;
 895         return 0;
 896 }
 897
 898 /*
 899  * "refresh" does not calculate a new sha1 file or bring the
 900  * cache up-to-date for mode/content changes. But what it
 901  * _does_ do is to "re-match" the stat information of a file
 902  * with the cache, so that you can refresh the cache for a
 903  * file that hasn't been changed but where the stat entry is
 904  * out of date.
 905  *
 906  * For example, you'd want to do this after doing a "git-read-tree",
 907  * to link up the stat cache details with the proper files.
 908  */
 909 static struct cache_entry *refresh_cache_ent(struct index_state *istate,
 910                                              struct cache_entry *ce,
 911                                              unsigned int options, int *err)
 912 {
 913         struct stat st;
 914         struct cache_entry *updated;
 915         int changed, size;
 916         int ignore_valid = options & CE_MATCH_IGNORE_VALID;
 917
 918         if (ce_uptodate(ce))
 919                 return ce;
 920
 921         if (lstat(ce->name, &st) < 0) {
 922                 if (err)
 923                         *err = errno;
 924                 return NULL;
 925         }
 926
 927         changed = ie_match_stat(istate, ce, &st, options);
 928         if (!changed) {
 929                 /*
 930                  * The path is unchanged.  If we were told to ignore
 931                  * valid bit, then we did the actual stat check and
 932                  * found that the entry is unmodified.  If the entry
 933                  * is not marked VALID, this is the place to mark it
 934                  * valid again, under "assume unchanged" mode.
 935                  */
 936                 if (ignore_valid && assume_unchanged &&
 937                     !(ce->ce_flags & CE_VALID))
 938                         ; /* mark this one VALID again */
 939                 else {
 940                         /*
 941                          * We do not mark the index itself "modified"
 942                          * because CE_UPTODATE flag is in-core only;
 943                          * we are not going to write this change out.
 944                          */
 945                         ce_mark_uptodate(ce);
 946                         return ce;
 947                 }
 948         }
 949
 950         if (ie_modified(istate, ce, &st, options)) {
 951                 if (err)
 952                         *err = EINVAL;
 953                 return NULL;
 954         }
 955
 956         size = ce_size(ce);
 957         updated = xmalloc(size);
 958         memcpy(updated, ce, size);
 959         fill_stat_cache_info(updated, &st);
 960         /*
 961          * If ignore_valid is not set, we should leave CE_VALID bit
 962          * alone.  Otherwise, paths marked with --no-assume-unchanged
 963          * (i.e. things to be edited) will reacquire CE_VALID bit
 964          * automatically, which is not really what we want.
 965          */
 966         if (!ignore_valid && assume_unchanged &&
 967             !(ce->ce_flags & CE_VALID))
 968                 updated->ce_flags &= ~CE_VALID;
 969
 970         return updated;
 971 }
 972
 973 int refresh_index(struct index_state *istate, unsigned int flags, const char **pathspec, char *seen)
 974 {
 975         int i;
 976         int has_errors = 0;
 977         int really = (flags & REFRESH_REALLY) != 0;
 978         int allow_unmerged = (flags & REFRESH_UNMERGED) != 0;
 979         int quiet = (flags & REFRESH_QUIET) != 0;
 980         int not_new = (flags & REFRESH_IGNORE_MISSING) != 0;
 981         unsigned int options = really ? CE_MATCH_IGNORE_VALID : 0;
 982
 983         for (i = 0; i < istate->cache_nr; i++) {
 984                 struct cache_entry *ce, *new;
 985                 int cache_errno = 0;
 986
 987                 ce = istate->cache[i];
 988                 if (ce_stage(ce)) {
 989                         while ((i < istate->cache_nr) &&
 990                                ! strcmp(istate->cache[i]->name, ce->name))
 991                                 i++;
 992                         i--;
 993                         if (allow_unmerged)
 994                                 continue;
 995                         printf("%s: needs merge\n", ce->name);
 996                         has_errors = 1;
 997                         continue;
 998                 }
 999
1000                 if (pathspec && !match_pathspec(pathspec, ce->name, strlen(ce->name), 0, seen))
1001                         continue;
1002
1003                 new = refresh_cache_ent(istate, ce, options, &cache_errno);
1004                 if (new == ce)
1005                         continue;
1006                 if (!new) {
1007                         if (not_new && cache_errno == ENOENT)
1008                                 continue;
1009                         if (really && cache_errno == EINVAL) {
1010                                 /* If we are doing --really-refresh that
1011                                  * means the index is not valid anymore.
1012                                  */
1013                                 ce->ce_flags &= ~CE_VALID;
1014                                 istate->cache_changed = 1;
1015                         }
1016                         if (quiet)
1017                                 continue;
1018                         printf("%s: needs update\n", ce->name);
1019                         has_errors = 1;
1020                         continue;
1021                 }
1022
1023                 replace_index_entry(istate, i, new);
1024         }
1025         return has_errors;
1026 }
1027
1028 struct cache_entry *refresh_cache_entry(struct cache_entry *ce, int really)
1029 {
1030         return refresh_cache_ent(&the_index, ce, really, NULL);
1031 }
1032
1033 static int verify_hdr(struct cache_header *hdr, unsigned long size)
1034 {
1035         SHA_CTX c;
1036         unsigned char sha1[20];
1037
1038         if (hdr->hdr_signature != htonl(CACHE_SIGNATURE))
1039                 return error("bad signature");
1040         if (hdr->hdr_version != htonl(2))
1041                 return error("bad index version");
1042         SHA1_Init(&c);
1043         SHA1_Update(&c, hdr, size - 20);
1044         SHA1_Final(sha1, &c);
1045         if (hashcmp(sha1, (unsigned char *)hdr + size - 20))
1046                 return error("bad index file sha1 signature");
1047         return 0;
1048 }
1049
1050 static int read_index_extension(struct index_state *istate,
1051                                 const char *ext, void *data, unsigned long sz)
1052 {
1053         switch (CACHE_EXT(ext)) {
1054         case CACHE_EXT_TREE:
1055                 istate->cache_tree = cache_tree_read(data, sz);
1056                 break;
1057         default:
1058                 if (*ext < 'A' || 'Z' < *ext)
1059                         return error("index uses %.4s extension, which we do not understand",
1060                                      ext);
1061                 fprintf(stderr, "ignoring %.4s extension\n", ext);
1062                 break;
1063         }
1064         return 0;
1065 }
1066
1067 int read_index(struct index_state *istate)
1068 {
1069         return read_index_from(istate, get_index_file());
1070 }
1071
1072 static void convert_from_disk(struct ondisk_cache_entry *ondisk, struct cache_entry *ce)
1073 {
1074         size_t len;
1075
1076         ce->ce_ctime = ntohl(ondisk->ctime.sec);
1077         ce->ce_mtime = ntohl(ondisk->mtime.sec);
1078         ce->ce_dev   = ntohl(ondisk->dev);
1079         ce->ce_ino   = ntohl(ondisk->ino);
1080         ce->ce_mode  = ntohl(ondisk->mode);
1081         ce->ce_uid   = ntohl(ondisk->uid);
1082         ce->ce_gid   = ntohl(ondisk->gid);
1083         ce->ce_size  = ntohl(ondisk->size);
1084         /* On-disk flags are just 16 bits */
1085         ce->ce_flags = ntohs(ondisk->flags);
1086         hashcpy(ce->sha1, ondisk->sha1);
1087
1088         len = ce->ce_flags & CE_NAMEMASK;
1089         if (len == CE_NAMEMASK)
1090                 len = strlen(ondisk->name);
1091         /*
1092          * NEEDSWORK: If the original index is crafted, this copy could
1093          * go unchecked.
1094          */
1095         memcpy(ce->name, ondisk->name, len + 1);
1096 }
1097
1098 static inline size_t estimate_cache_size(size_t ondisk_size, unsigned int entries)
1099 {
1100         long per_entry;
1101
1102         per_entry = sizeof(struct cache_entry) - sizeof(struct ondisk_cache_entry);
1103
1104         /*
1105          * Alignment can cause differences. This should be "alignof", but
1106          * since that's a gcc'ism, just use the size of a pointer.
1107          */
1108         per_entry += sizeof(void *);
1109         return ondisk_size + entries*per_entry;
1110 }
1111
1112 /* remember to discard_cache() before reading a different cache! */
1113 int read_index_from(struct index_state *istate, const char *path)
1114 {
1115         int fd, i;
1116         struct stat st;
1117         unsigned long src_offset, dst_offset;
1118         struct cache_header *hdr;
1119         void *mmap;
1120         size_t mmap_size;
1121
1122         errno = EBUSY;
1123         if (istate->alloc)
1124                 return istate->cache_nr;
1125
1126         errno = ENOENT;
1127         istate->timestamp = 0;
1128         fd = open(path, O_RDONLY);
1129         if (fd < 0) {
1130                 if (errno == ENOENT)
1131                         return 0;
1132                 die("index file open failed (%s)", strerror(errno));
1133         }
1134
1135         if (fstat(fd, &st))
1136                 die("cannot stat the open index (%s)", strerror(errno));
1137
1138         errno = EINVAL;
1139         mmap_size = xsize_t(st.st_size);
1140         if (mmap_size < sizeof(struct cache_header) + 20)
1141                 die("index file smaller than expected");
1142
1143         mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
1144         close(fd);
1145         if (mmap == MAP_FAILED)
1146                 die("unable to map index file");
1147
1148         hdr = mmap;
1149         if (verify_hdr(hdr, mmap_size) < 0)
1150                 goto unmap;
1151
1152         istate->cache_nr = ntohl(hdr->hdr_entries);
1153         istate->cache_alloc = alloc_nr(istate->cache_nr);
1154         istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *));
1155
1156         /*
1157          * The disk format is actually larger than the in-memory format,
1158          * due to space for nsec etc, so even though the in-memory one
1159          * has room for a few  more flags, we can allocate using the same
1160          * index size
1161          */
1162         istate->alloc = xmalloc(estimate_cache_size(mmap_size, istate->cache_nr));
1163
1164         src_offset = sizeof(*hdr);
1165         dst_offset = 0;
1166         for (i = 0; i < istate->cache_nr; i++) {
1167                 struct ondisk_cache_entry *disk_ce;
1168                 struct cache_entry *ce;
1169
1170                 disk_ce = (struct ondisk_cache_entry *)((char *)mmap + src_offset);
1171                 ce = (struct cache_entry *)((char *)istate->alloc + dst_offset);
1172                 convert_from_disk(disk_ce, ce);
1173                 set_index_entry(istate, i, ce);
1174
1175                 src_offset += ondisk_ce_size(ce);
1176                 dst_offset += ce_size(ce);
1177         }
1178         istate->timestamp = st.st_mtime;
1179         while (src_offset <= mmap_size - 20 - 8) {
1180                 /* After an array of active_nr index entries,
1181                  * there can be arbitrary number of extended
1182                  * sections, each of which is prefixed with
1183                  * extension name (4-byte) and section length
1184                  * in 4-byte network byte order.
1185                  */
1186                 unsigned long extsize;
1187                 memcpy(&extsize, (char *)mmap + src_offset + 4, 4);
1188                 extsize = ntohl(extsize);
1189                 if (read_index_extension(istate,
1190                                          (const char *) mmap + src_offset,
1191                                          (char *) mmap + src_offset + 8,
1192                                          extsize) < 0)
1193                         goto unmap;
1194                 src_offset += 8;
1195                 src_offset += extsize;
1196         }
1197         munmap(mmap, mmap_size);
1198         return istate->cache_nr;
1199
1200 unmap:
1201         munmap(mmap, mmap_size);
1202         errno = EINVAL;
1203         die("index file corrupt");
1204 }
1205
1206 int discard_index(struct index_state *istate)
1207 {
1208         istate->cache_nr = 0;
1209         istate->cache_changed = 0;
1210         istate->timestamp = 0;
1211         free_hash(&istate->name_hash);
1212         cache_tree_free(&(istate->cache_tree));
1213         free(istate->alloc);
1214         istate->alloc = NULL;
1215
1216         /* no need to throw away allocated active_cache */
1217         return 0;
1218 }
1219
1220 int unmerged_index(const struct index_state *istate)
1221 {
1222         int i;
1223         for (i = 0; i < istate->cache_nr; i++) {
1224                 if (ce_stage(istate->cache[i]))
1225                         return 1;
1226         }
1227         return 0;
1228 }
1229
1230 #define WRITE_BUFFER_SIZE 8192
1231 static unsigned char write_buffer[WRITE_BUFFER_SIZE];
1232 static unsigned long write_buffer_len;
1233
1234 static int ce_write_flush(SHA_CTX *context, int fd)
1235 {
1236         unsigned int buffered = write_buffer_len;
1237         if (buffered) {
1238                 SHA1_Update(context, write_buffer, buffered);
1239                 if (write_in_full(fd, write_buffer, buffered) != buffered)
1240                         return -1;
1241                 write_buffer_len = 0;
1242         }
1243         return 0;
1244 }
1245
1246 static int ce_write(SHA_CTX *context, int fd, void *data, unsigned int len)
1247 {
1248         while (len) {
1249                 unsigned int buffered = write_buffer_len;
1250                 unsigned int partial = WRITE_BUFFER_SIZE - buffered;
1251                 if (partial > len)
1252                         partial = len;
1253                 memcpy(write_buffer + buffered, data, partial);
1254                 buffered += partial;
1255                 if (buffered == WRITE_BUFFER_SIZE) {
1256                         write_buffer_len = buffered;
1257                         if (ce_write_flush(context, fd))
1258                                 return -1;
1259                         buffered = 0;
1260                 }
1261                 write_buffer_len = buffered;
1262                 len -= partial;
1263                 data = (char *) data + partial;
1264         }
1265         return 0;
1266 }
1267
1268 static int write_index_ext_header(SHA_CTX *context, int fd,
1269                                   unsigned int ext, unsigned int sz)
1270 {
1271         ext = htonl(ext);
1272         sz = htonl(sz);
1273         return ((ce_write(context, fd, &ext, 4) < 0) ||
1274                 (ce_write(context, fd, &sz, 4) < 0)) ? -1 : 0;
1275 }
1276
1277 static int ce_flush(SHA_CTX *context, int fd)
1278 {
1279         unsigned int left = write_buffer_len;
1280
1281         if (left) {
1282                 write_buffer_len = 0;
1283                 SHA1_Update(context, write_buffer, left);
1284         }
1285
1286         /* Flush first if not enough space for SHA1 signature */
1287         if (left + 20 > WRITE_BUFFER_SIZE) {
1288                 if (write_in_full(fd, write_buffer, left) != left)
1289                         return -1;
1290                 left = 0;
1291         }
1292
1293         /* Append the SHA1 signature at the end */
1294         SHA1_Final(write_buffer + left, context);
1295         left += 20;
1296         return (write_in_full(fd, write_buffer, left) != left) ? -1 : 0;
1297 }
1298
1299 static void ce_smudge_racily_clean_entry(struct cache_entry *ce)
1300 {
1301         /*
1302          * The only thing we care about in this function is to smudge the
1303          * falsely clean entry due to touch-update-touch race, so we leave
1304          * everything else as they are.  We are called for entries whose
1305          * ce_mtime match the index file mtime.
1306          */
1307         struct stat st;
1308
1309         if (lstat(ce->name, &st) < 0)
1310                 return;
1311         if (ce_match_stat_basic(ce, &st))
1312                 return;
1313         if (ce_modified_check_fs(ce, &st)) {
1314                 /* This is "racily clean"; smudge it.  Note that this
1315                  * is a tricky code.  At first glance, it may appear
1316                  * that it can break with this sequence:
1317                  *
1318                  * $ echo xyzzy >frotz
1319                  * $ git-update-index --add frotz
1320                  * $ : >frotz
1321                  * $ sleep 3
1322                  * $ echo filfre >nitfol
1323                  * $ git-update-index --add nitfol
1324                  *
1325                  * but it does not.  When the second update-index runs,
1326                  * it notices that the entry "frotz" has the same timestamp
1327                  * as index, and if we were to smudge it by resetting its
1328                  * size to zero here, then the object name recorded
1329                  * in index is the 6-byte file but the cached stat information
1330                  * becomes zero --- which would then match what we would
1331                  * obtain from the filesystem next time we stat("frotz").
1332                  *
1333                  * However, the second update-index, before calling
1334                  * this function, notices that the cached size is 6
1335                  * bytes and what is on the filesystem is an empty
1336                  * file, and never calls us, so the cached size information
1337                  * for "frotz" stays 6 which does not match the filesystem.
1338                  */
1339                 ce->ce_size = 0;
1340         }
1341 }
1342
1343 static int ce_write_entry(SHA_CTX *c, int fd, struct cache_entry *ce)
1344 {
1345         int size = ondisk_ce_size(ce);
1346         struct ondisk_cache_entry *ondisk = xcalloc(1, size);
1347
1348         ondisk->ctime.sec = htonl(ce->ce_ctime);
1349         ondisk->ctime.nsec = 0;
1350         ondisk->mtime.sec = htonl(ce->ce_mtime);
1351         ondisk->mtime.nsec = 0;
1352         ondisk->dev  = htonl(ce->ce_dev);
1353         ondisk->ino  = htonl(ce->ce_ino);
1354         ondisk->mode = htonl(ce->ce_mode);
1355         ondisk->uid  = htonl(ce->ce_uid);
1356         ondisk->gid  = htonl(ce->ce_gid);
1357         ondisk->size = htonl(ce->ce_size);
1358         hashcpy(ondisk->sha1, ce->sha1);
1359         ondisk->flags = htons(ce->ce_flags);
1360         memcpy(ondisk->name, ce->name, ce_namelen(ce));
1361
1362         return ce_write(c, fd, ondisk, size);
1363 }
1364
1365 int write_index(const struct index_state *istate, int newfd)
1366 {
1367         SHA_CTX c;
1368         struct cache_header hdr;
1369         int i, err, removed;
1370         struct cache_entry **cache = istate->cache;
1371         int entries = istate->cache_nr;
1372
1373         for (i = removed = 0; i < entries; i++)
1374                 if (cache[i]->ce_flags & CE_REMOVE)
1375                         removed++;
1376
1377         hdr.hdr_signature = htonl(CACHE_SIGNATURE);
1378         hdr.hdr_version = htonl(2);
1379         hdr.hdr_entries = htonl(entries - removed);
1380
1381         SHA1_Init(&c);
1382         if (ce_write(&c, newfd, &hdr, sizeof(hdr)) < 0)
1383                 return -1;
1384
1385         for (i = 0; i < entries; i++) {
1386                 struct cache_entry *ce = cache[i];
1387                 if (ce->ce_flags & CE_REMOVE)
1388                         continue;
1389                 if (is_racy_timestamp(istate, ce))
1390                         ce_smudge_racily_clean_entry(ce);
1391                 if (ce_write_entry(&c, newfd, ce) < 0)
1392                         return -1;
1393         }
1394
1395         /* Write extension data here */
1396         if (istate->cache_tree) {
1397                 struct strbuf sb;
1398
1399                 strbuf_init(&sb, 0);
1400                 cache_tree_write(&sb, istate->cache_tree);
1401                 err = write_index_ext_header(&c, newfd, CACHE_EXT_TREE, sb.len) < 0
1402                         || ce_write(&c, newfd, sb.buf, sb.len) < 0;
1403                 strbuf_release(&sb);
1404                 if (err)
1405                         return -1;
1406         }
1407         return ce_flush(&c, newfd);
1408 }