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