attr.c

   1 #define NO_THE_INDEX_COMPATIBILITY_MACROS
   2 #include "cache.h"
   3 #include "exec_cmd.h"
   4 #include "attr.h"
   5
   6 const char git_attr__true[] = "(builtin)true";
   7 const char git_attr__false[] = "\0(builtin)false";
   8 static const char git_attr__unknown[] = "(builtin)unknown";
   9 #define ATTR__TRUE git_attr__true
  10 #define ATTR__FALSE git_attr__false
  11 #define ATTR__UNSET NULL
  12 #define ATTR__UNKNOWN git_attr__unknown
  13
  14 static const char *attributes_file;
  15
  16 /*
  17  * The basic design decision here is that we are not going to have
  18  * insanely large number of attributes.
  19  *
  20  * This is a randomly chosen prime.
  21  */
  22 #define HASHSIZE 257
  23
  24 #ifndef DEBUG_ATTR
  25 #define DEBUG_ATTR 0
  26 #endif
  27
  28 struct git_attr {
  29         struct git_attr *next;
  30         unsigned h;
  31         int attr_nr;
  32         char name[FLEX_ARRAY];
  33 };
  34 static int attr_nr;
  35
  36 static struct git_attr_check *check_all_attr;
  37 static struct git_attr *(git_attr_hash[HASHSIZE]);
  38
  39 static unsigned hash_name(const char *name, int namelen)
  40 {
  41         unsigned val = 0, c;
  42
  43         while (namelen--) {
  44                 c = *name++;
  45                 val = ((val << 7) | (val >> 22)) ^ c;
  46         }
  47         return val;
  48 }
  49
  50 static int invalid_attr_name(const char *name, int namelen)
  51 {
  52         /*
  53          * Attribute name cannot begin with '-' and must consist of
  54          * characters from [-A-Za-z0-9_.].
  55          */
  56         if (*name == '-')
  57                 return -1;
  58         while (namelen--) {
  59                 char ch = *name++;
  60                 if (! (ch == '-' || ch == '.' || ch == '_' ||
  61                        ('0' <= ch && ch <= '9') ||
  62                        ('a' <= ch && ch <= 'z') ||
  63                        ('A' <= ch && ch <= 'Z')) )
  64                         return -1;
  65         }
  66         return 0;
  67 }
  68
  69 static struct git_attr *git_attr_internal(const char *name, int len)
  70 {
  71         unsigned hval = hash_name(name, len);
  72         unsigned pos = hval % HASHSIZE;
  73         struct git_attr *a;
  74
  75         for (a = git_attr_hash[pos]; a; a = a->next) {
  76                 if (a->h == hval &&
  77                     !memcmp(a->name, name, len) && !a->name[len])
  78                         return a;
  79         }
  80
  81         if (invalid_attr_name(name, len))
  82                 return NULL;
  83
  84         a = xmalloc(sizeof(*a) + len + 1);
  85         memcpy(a->name, name, len);
  86         a->name[len] = 0;
  87         a->h = hval;
  88         a->next = git_attr_hash[pos];
  89         a->attr_nr = attr_nr++;
  90         git_attr_hash[pos] = a;
  91
  92         check_all_attr = xrealloc(check_all_attr,
  93                                   sizeof(*check_all_attr) * attr_nr);
  94         check_all_attr[a->attr_nr].attr = a;
  95         check_all_attr[a->attr_nr].value = ATTR__UNKNOWN;
  96         return a;
  97 }
  98
  99 struct git_attr *git_attr(const char *name)
 100 {
 101         return git_attr_internal(name, strlen(name));
 102 }
 103
 104 /*
 105  * .gitattributes file is one line per record, each of which is
 106  *
 107  * (1) glob pattern.
 108  * (2) whitespace
 109  * (3) whitespace separated list of attribute names, each of which
 110  *     could be prefixed with '-' to mean "set to false", '!' to mean
 111  *     "unset".
 112  */
 113
 114 /* What does a matched pattern decide? */
 115 struct attr_state {
 116         struct git_attr *attr;
 117         const char *setto;
 118 };
 119
 120 struct match_attr {
 121         union {
 122                 char *pattern;
 123                 struct git_attr *attr;
 124         } u;
 125         char is_macro;
 126         unsigned num_attr;
 127         struct attr_state state[FLEX_ARRAY];
 128 };
 129
 130 static const char blank[] = " \t\r\n";
 131
 132 static const char *parse_attr(const char *src, int lineno, const char *cp,
 133                               int *num_attr, struct match_attr *res)
 134 {
 135         const char *ep, *equals;
 136         int len;
 137
 138         ep = cp + strcspn(cp, blank);
 139         equals = strchr(cp, '=');
 140         if (equals && ep < equals)
 141                 equals = NULL;
 142         if (equals)
 143                 len = equals - cp;
 144         else
 145                 len = ep - cp;
 146         if (!res) {
 147                 if (*cp == '-' || *cp == '!') {
 148                         cp++;
 149                         len--;
 150                 }
 151                 if (invalid_attr_name(cp, len)) {
 152                         fprintf(stderr,
 153                                 "%.*s is not a valid attribute name: %s:%d\n",
 154                                 len, cp, src, lineno);
 155                         return NULL;
 156                 }
 157         } else {
 158                 struct attr_state *e;
 159
 160                 e = &(res->state[*num_attr]);
 161                 if (*cp == '-' || *cp == '!') {
 162                         e->setto = (*cp == '-') ? ATTR__FALSE : ATTR__UNSET;
 163                         cp++;
 164                         len--;
 165                 }
 166                 else if (!equals)
 167                         e->setto = ATTR__TRUE;
 168                 else {
 169                         e->setto = xmemdupz(equals + 1, ep - equals - 1);
 170                 }
 171                 e->attr = git_attr_internal(cp, len);
 172         }
 173         (*num_attr)++;
 174         return ep + strspn(ep, blank);
 175 }
 176
 177 static struct match_attr *parse_attr_line(const char *line, const char *src,
 178                                           int lineno, int macro_ok)
 179 {
 180         int namelen;
 181         int num_attr;
 182         const char *cp, *name;
 183         struct match_attr *res = NULL;
 184         int pass;
 185         int is_macro;
 186
 187         cp = line + strspn(line, blank);
 188         if (!*cp || *cp == '#')
 189                 return NULL;
 190         name = cp;
 191         namelen = strcspn(name, blank);
 192         if (strlen(ATTRIBUTE_MACRO_PREFIX) < namelen &&
 193             !prefixcmp(name, ATTRIBUTE_MACRO_PREFIX)) {
 194                 if (!macro_ok) {
 195                         fprintf(stderr, "%s not allowed: %s:%d\n",
 196                                 name, src, lineno);
 197                         return NULL;
 198                 }
 199                 is_macro = 1;
 200                 name += strlen(ATTRIBUTE_MACRO_PREFIX);
 201                 name += strspn(name, blank);
 202                 namelen = strcspn(name, blank);
 203                 if (invalid_attr_name(name, namelen)) {
 204                         fprintf(stderr,
 205                                 "%.*s is not a valid attribute name: %s:%d\n",
 206                                 namelen, name, src, lineno);
 207                         return NULL;
 208                 }
 209         }
 210         else
 211                 is_macro = 0;
 212
 213         for (pass = 0; pass < 2; pass++) {
 214                 /* pass 0 counts and allocates, pass 1 fills */
 215                 num_attr = 0;
 216                 cp = name + namelen;
 217                 cp = cp + strspn(cp, blank);
 218                 while (*cp) {
 219                         cp = parse_attr(src, lineno, cp, &num_attr, res);
 220                         if (!cp)
 221                                 return NULL;
 222                 }
 223                 if (pass)
 224                         break;
 225                 res = xcalloc(1,
 226                               sizeof(*res) +
 227                               sizeof(struct attr_state) * num_attr +
 228                               (is_macro ? 0 : namelen + 1));
 229                 if (is_macro)
 230                         res->u.attr = git_attr_internal(name, namelen);
 231                 else {
 232                         res->u.pattern = (char *)&(res->state[num_attr]);
 233                         memcpy(res->u.pattern, name, namelen);
 234                         res->u.pattern[namelen] = 0;
 235                 }
 236                 res->is_macro = is_macro;
 237                 res->num_attr = num_attr;
 238         }
 239         return res;
 240 }
 241
 242 /*
 243  * Like info/exclude and .gitignore, the attribute information can
 244  * come from many places.
 245  *
 246  * (1) .gitattribute file of the same directory;
 247  * (2) .gitattribute file of the parent directory if (1) does not have
 248  *      any match; this goes recursively upwards, just like .gitignore.
 249  * (3) $GIT_DIR/info/attributes, which overrides both of the above.
 250  *
 251  * In the same file, later entries override the earlier match, so in the
 252  * global list, we would have entries from info/attributes the earliest
 253  * (reading the file from top to bottom), .gitattribute of the root
 254  * directory (again, reading the file from top to bottom) down to the
 255  * current directory, and then scan the list backwards to find the first match.
 256  * This is exactly the same as what excluded() does in dir.c to deal with
 257  * .gitignore
 258  */
 259
 260 static struct attr_stack {
 261         struct attr_stack *prev;
 262         char *origin;
 263         unsigned num_matches;
 264         unsigned alloc;
 265         struct match_attr **attrs;
 266 } *attr_stack;
 267
 268 static void free_attr_elem(struct attr_stack *e)
 269 {
 270         int i;
 271         free(e->origin);
 272         for (i = 0; i < e->num_matches; i++) {
 273                 struct match_attr *a = e->attrs[i];
 274                 int j;
 275                 for (j = 0; j < a->num_attr; j++) {
 276                         const char *setto = a->state[j].setto;
 277                         if (setto == ATTR__TRUE ||
 278                             setto == ATTR__FALSE ||
 279                             setto == ATTR__UNSET ||
 280                             setto == ATTR__UNKNOWN)
 281                                 ;
 282                         else
 283                                 free((char *) setto);
 284                 }
 285                 free(a);
 286         }
 287         free(e);
 288 }
 289
 290 static const char *builtin_attr[] = {
 291         "[attr]binary -diff -text",
 292         NULL,
 293 };
 294
 295 static void handle_attr_line(struct attr_stack *res,
 296                              const char *line,
 297                              const char *src,
 298                              int lineno,
 299                              int macro_ok)
 300 {
 301         struct match_attr *a;
 302
 303         a = parse_attr_line(line, src, lineno, macro_ok);
 304         if (!a)
 305                 return;
 306         if (res->alloc <= res->num_matches) {
 307                 res->alloc = alloc_nr(res->num_matches);
 308                 res->attrs = xrealloc(res->attrs,
 309                                       sizeof(struct match_attr *) *
 310                                       res->alloc);
 311         }
 312         res->attrs[res->num_matches++] = a;
 313 }
 314
 315 static struct attr_stack *read_attr_from_array(const char **list)
 316 {
 317         struct attr_stack *res;
 318         const char *line;
 319         int lineno = 0;
 320
 321         res = xcalloc(1, sizeof(*res));
 322         while ((line = *(list++)) != NULL)
 323                 handle_attr_line(res, line, "[builtin]", ++lineno, 1);
 324         return res;
 325 }
 326
 327 static enum git_attr_direction direction;
 328 static struct index_state *use_index;
 329
 330 static struct attr_stack *read_attr_from_file(const char *path, int macro_ok)
 331 {
 332         FILE *fp = fopen(path, "r");
 333         struct attr_stack *res;
 334         char buf[2048];
 335         int lineno = 0;
 336
 337         if (!fp)
 338                 return NULL;
 339         res = xcalloc(1, sizeof(*res));
 340         while (fgets(buf, sizeof(buf), fp))
 341                 handle_attr_line(res, buf, path, ++lineno, macro_ok);
 342         fclose(fp);
 343         return res;
 344 }
 345
 346 static void *read_index_data(const char *path)
 347 {
 348         int pos, len;
 349         unsigned long sz;
 350         enum object_type type;
 351         void *data;
 352         struct index_state *istate = use_index ? use_index : &the_index;
 353
 354         len = strlen(path);
 355         pos = index_name_pos(istate, path, len);
 356         if (pos < 0) {
 357                 /*
 358                  * We might be in the middle of a merge, in which
 359                  * case we would read stage #2 (ours).
 360                  */
 361                 int i;
 362                 for (i = -pos - 1;
 363                      (pos < 0 && i < istate->cache_nr &&
 364                       !strcmp(istate->cache[i]->name, path));
 365                      i++)
 366                         if (ce_stage(istate->cache[i]) == 2)
 367                                 pos = i;
 368         }
 369         if (pos < 0)
 370                 return NULL;
 371         data = read_sha1_file(istate->cache[pos]->sha1, &type, &sz);
 372         if (!data || type != OBJ_BLOB) {
 373                 free(data);
 374                 return NULL;
 375         }
 376         return data;
 377 }
 378
 379 static struct attr_stack *read_attr_from_index(const char *path, int macro_ok)
 380 {
 381         struct attr_stack *res;
 382         char *buf, *sp;
 383         int lineno = 0;
 384
 385         buf = read_index_data(path);
 386         if (!buf)
 387                 return NULL;
 388
 389         res = xcalloc(1, sizeof(*res));
 390         for (sp = buf; *sp; ) {
 391                 char *ep;
 392                 int more;
 393                 for (ep = sp; *ep && *ep != '\n'; ep++)
 394                         ;
 395                 more = (*ep == '\n');
 396                 *ep = '\0';
 397                 handle_attr_line(res, sp, path, ++lineno, macro_ok);
 398                 sp = ep + more;
 399         }
 400         free(buf);
 401         return res;
 402 }
 403
 404 static struct attr_stack *read_attr(const char *path, int macro_ok)
 405 {
 406         struct attr_stack *res;
 407
 408         if (direction == GIT_ATTR_CHECKOUT) {
 409                 res = read_attr_from_index(path, macro_ok);
 410                 if (!res)
 411                         res = read_attr_from_file(path, macro_ok);
 412         }
 413         else if (direction == GIT_ATTR_CHECKIN) {
 414                 res = read_attr_from_file(path, macro_ok);
 415                 if (!res)
 416                         /*
 417                          * There is no checked out .gitattributes file there, but
 418                          * we might have it in the index.  We allow operation in a
 419                          * sparsely checked out work tree, so read from it.
 420                          */
 421                         res = read_attr_from_index(path, macro_ok);
 422         }
 423         else
 424                 res = read_attr_from_index(path, macro_ok);
 425         if (!res)
 426                 res = xcalloc(1, sizeof(*res));
 427         return res;
 428 }
 429
 430 #if DEBUG_ATTR
 431 static void debug_info(const char *what, struct attr_stack *elem)
 432 {
 433         fprintf(stderr, "%s: %s\n", what, elem->origin ? elem->origin : "()");
 434 }
 435 static void debug_set(const char *what, const char *match, struct git_attr *attr, const void *v)
 436 {
 437         const char *value = v;
 438
 439         if (ATTR_TRUE(value))
 440                 value = "set";
 441         else if (ATTR_FALSE(value))
 442                 value = "unset";
 443         else if (ATTR_UNSET(value))
 444                 value = "unspecified";
 445
 446         fprintf(stderr, "%s: %s => %s (%s)\n",
 447                 what, attr->name, (char *) value, match);
 448 }
 449 #define debug_push(a) debug_info("push", (a))
 450 #define debug_pop(a) debug_info("pop", (a))
 451 #else
 452 #define debug_push(a) do { ; } while (0)
 453 #define debug_pop(a) do { ; } while (0)
 454 #define debug_set(a,b,c,d) do { ; } while (0)
 455 #endif
 456
 457 static void drop_attr_stack(void)
 458 {
 459         while (attr_stack) {
 460                 struct attr_stack *elem = attr_stack;
 461                 attr_stack = elem->prev;
 462                 free_attr_elem(elem);
 463         }
 464 }
 465
 466 static const char *git_etc_gitattributes(void)
 467 {
 468         static const char *system_wide;
 469         if (!system_wide)
 470                 system_wide = system_path(ETC_GITATTRIBUTES);
 471         return system_wide;
 472 }
 473
 474 static int git_attr_system(void)
 475 {
 476         return !git_env_bool("GIT_ATTR_NOSYSTEM", 0);
 477 }
 478
 479 static int git_attr_config(const char *var, const char *value, void *dummy)
 480 {
 481         if (!strcmp(var, "core.attributesfile"))
 482                 return git_config_pathname(&attributes_file, var, value);
 483
 484         return 0;
 485 }
 486
 487 static void bootstrap_attr_stack(void)
 488 {
 489         if (!attr_stack) {
 490                 struct attr_stack *elem;
 491
 492                 elem = read_attr_from_array(builtin_attr);
 493                 elem->origin = NULL;
 494                 elem->prev = attr_stack;
 495                 attr_stack = elem;
 496
 497                 if (git_attr_system()) {
 498                         elem = read_attr_from_file(git_etc_gitattributes(), 1);
 499                         if (elem) {
 500                                 elem->origin = NULL;
 501                                 elem->prev = attr_stack;
 502                                 attr_stack = elem;
 503                         }
 504                 }
 505
 506                 git_config(git_attr_config, NULL);
 507                 if (attributes_file) {
 508                         elem = read_attr_from_file(attributes_file, 1);
 509                         if (elem) {
 510                                 elem->origin = NULL;
 511                                 elem->prev = attr_stack;
 512                                 attr_stack = elem;
 513                         }
 514                 }
 515
 516                 if (!is_bare_repository() || direction == GIT_ATTR_INDEX) {
 517                         elem = read_attr(GITATTRIBUTES_FILE, 1);
 518                         elem->origin = strdup("");
 519                         elem->prev = attr_stack;
 520                         attr_stack = elem;
 521                         debug_push(elem);
 522                 }
 523
 524                 elem = read_attr_from_file(git_path(INFOATTRIBUTES_FILE), 1);
 525                 if (!elem)
 526                         elem = xcalloc(1, sizeof(*elem));
 527                 elem->origin = NULL;
 528                 elem->prev = attr_stack;
 529                 attr_stack = elem;
 530         }
 531 }
 532
 533 static void prepare_attr_stack(const char *path, int dirlen)
 534 {
 535         struct attr_stack *elem, *info;
 536         int len;
 537         struct strbuf pathbuf;
 538
 539         strbuf_init(&pathbuf, dirlen+2+strlen(GITATTRIBUTES_FILE));
 540
 541         /*
 542          * At the bottom of the attribute stack is the built-in
 543          * set of attribute definitions, followed by the contents
 544          * of $(prefix)/etc/gitattributes and a file specified by
 545          * core.attributesfile.  Then, contents from
 546          * .gitattribute files from directories closer to the
 547          * root to the ones in deeper directories are pushed
 548          * to the stack.  Finally, at the very top of the stack
 549          * we always keep the contents of $GIT_DIR/info/attributes.
 550          *
 551          * When checking, we use entries from near the top of the
 552          * stack, preferring $GIT_DIR/info/attributes, then
 553          * .gitattributes in deeper directories to shallower ones,
 554          * and finally use the built-in set as the default.
 555          */
 556         if (!attr_stack)
 557                 bootstrap_attr_stack();
 558
 559         /*
 560          * Pop the "info" one that is always at the top of the stack.
 561          */
 562         info = attr_stack;
 563         attr_stack = info->prev;
 564
 565         /*
 566          * Pop the ones from directories that are not the prefix of
 567          * the path we are checking.
 568          */
 569         while (attr_stack && attr_stack->origin) {
 570                 int namelen = strlen(attr_stack->origin);
 571
 572                 elem = attr_stack;
 573                 if (namelen <= dirlen &&
 574                     !strncmp(elem->origin, path, namelen))
 575                         break;
 576
 577                 debug_pop(elem);
 578                 attr_stack = elem->prev;
 579                 free_attr_elem(elem);
 580         }
 581
 582         /*
 583          * Read from parent directories and push them down
 584          */
 585         if (!is_bare_repository() || direction == GIT_ATTR_INDEX) {
 586                 while (1) {
 587                         char *cp;
 588
 589                         len = strlen(attr_stack->origin);
 590                         if (dirlen <= len)
 591                                 break;
 592                         strbuf_reset(&pathbuf);
 593                         strbuf_add(&pathbuf, path, dirlen);
 594                         strbuf_addch(&pathbuf, '/');
 595                         cp = strchr(pathbuf.buf + len + 1, '/');
 596                         strcpy(cp + 1, GITATTRIBUTES_FILE);
 597                         elem = read_attr(pathbuf.buf, 0);
 598                         *cp = '\0';
 599                         elem->origin = strdup(pathbuf.buf);
 600                         elem->prev = attr_stack;
 601                         attr_stack = elem;
 602                         debug_push(elem);
 603                 }
 604         }
 605
 606         strbuf_release(&pathbuf);
 607
 608         /*
 609          * Finally push the "info" one at the top of the stack.
 610          */
 611         info->prev = attr_stack;
 612         attr_stack = info;
 613 }
 614
 615 static int path_matches(const char *pathname, int pathlen,
 616                         const char *pattern,
 617                         const char *base, int baselen)
 618 {
 619         if (!strchr(pattern, '/')) {
 620                 /* match basename */
 621                 const char *basename = strrchr(pathname, '/');
 622                 basename = basename ? basename + 1 : pathname;
 623                 return (fnmatch(pattern, basename, 0) == 0);
 624         }
 625         /*
 626          * match with FNM_PATHNAME; the pattern has base implicitly
 627          * in front of it.
 628          */
 629         if (*pattern == '/')
 630                 pattern++;
 631         if (pathlen < baselen ||
 632             (baselen && pathname[baselen] != '/') ||
 633             strncmp(pathname, base, baselen))
 634                 return 0;
 635         if (baselen != 0)
 636                 baselen++;
 637         return fnmatch(pattern, pathname + baselen, FNM_PATHNAME) == 0;
 638 }
 639
 640 static int macroexpand_one(int attr_nr, int rem);
 641
 642 static int fill_one(const char *what, struct match_attr *a, int rem)
 643 {
 644         struct git_attr_check *check = check_all_attr;
 645         int i;
 646
 647         for (i = a->num_attr - 1; 0 < rem && 0 <= i; i--) {
 648                 struct git_attr *attr = a->state[i].attr;
 649                 const char **n = &(check[attr->attr_nr].value);
 650                 const char *v = a->state[i].setto;
 651
 652                 if (*n == ATTR__UNKNOWN) {
 653                         debug_set(what,
 654                                   a->is_macro ? a->u.attr->name : a->u.pattern,
 655                                   attr, v);
 656                         *n = v;
 657                         rem--;
 658                         rem = macroexpand_one(attr->attr_nr, rem);
 659                 }
 660         }
 661         return rem;
 662 }
 663
 664 static int fill(const char *path, int pathlen, struct attr_stack *stk, int rem)
 665 {
 666         int i;
 667         const char *base = stk->origin ? stk->origin : "";
 668
 669         for (i = stk->num_matches - 1; 0 < rem && 0 <= i; i--) {
 670                 struct match_attr *a = stk->attrs[i];
 671                 if (a->is_macro)
 672                         continue;
 673                 if (path_matches(path, pathlen,
 674                                  a->u.pattern, base, strlen(base)))
 675                         rem = fill_one("fill", a, rem);
 676         }
 677         return rem;
 678 }
 679
 680 static int macroexpand_one(int attr_nr, int rem)
 681 {
 682         struct attr_stack *stk;
 683         struct match_attr *a = NULL;
 684         int i;
 685
 686         if (check_all_attr[attr_nr].value != ATTR__TRUE)
 687                 return rem;
 688
 689         for (stk = attr_stack; !a && stk; stk = stk->prev)
 690                 for (i = stk->num_matches - 1; !a && 0 <= i; i--) {
 691                         struct match_attr *ma = stk->attrs[i];
 692                         if (!ma->is_macro)
 693                                 continue;
 694                         if (ma->u.attr->attr_nr == attr_nr)
 695                                 a = ma;
 696                 }
 697
 698         if (a)
 699                 rem = fill_one("expand", a, rem);
 700
 701         return rem;
 702 }
 703
 704 int git_checkattr(const char *path, int num, struct git_attr_check *check)
 705 {
 706         struct attr_stack *stk;
 707         const char *cp;
 708         int dirlen, pathlen, i, rem;
 709
 710         bootstrap_attr_stack();
 711         for (i = 0; i < attr_nr; i++)
 712                 check_all_attr[i].value = ATTR__UNKNOWN;
 713
 714         pathlen = strlen(path);
 715         cp = strrchr(path, '/');
 716         if (!cp)
 717                 dirlen = 0;
 718         else
 719                 dirlen = cp - path;
 720         prepare_attr_stack(path, dirlen);
 721         rem = attr_nr;
 722         for (stk = attr_stack; 0 < rem && stk; stk = stk->prev)
 723                 rem = fill(path, pathlen, stk, rem);
 724
 725         for (i = 0; i < num; i++) {
 726                 const char *value = check_all_attr[check[i].attr->attr_nr].value;
 727                 if (value == ATTR__UNKNOWN)
 728                         value = ATTR__UNSET;
 729                 check[i].value = value;
 730         }
 731
 732         return 0;
 733 }
 734
 735 void git_attr_set_direction(enum git_attr_direction new, struct index_state *istate)
 736 {
 737         enum git_attr_direction old = direction;
 738
 739         if (is_bare_repository() && new != GIT_ATTR_INDEX)
 740                 die("BUG: non-INDEX attr direction in a bare repo");
 741
 742         direction = new;
 743         if (new != old)
 744                 drop_attr_stack();
 745         use_index = istate;
 746 }