setup.c

   1 #include "cache.h"
   2 #include "dir.h"
   3
   4 static int inside_git_dir = -1;
   5 static int inside_work_tree = -1;
   6
   7 char *prefix_path(const char *prefix, int len, const char *path)
   8 {
   9         const char *orig = path;
  10         char *sanitized;
  11         if (is_absolute_path(orig)) {
  12                 const char *temp = real_path(path);
  13                 sanitized = xmalloc(len + strlen(temp) + 1);
  14                 strcpy(sanitized, temp);
  15         } else {
  16                 sanitized = xmalloc(len + strlen(path) + 1);
  17                 if (len)
  18                         memcpy(sanitized, prefix, len);
  19                 strcpy(sanitized + len, path);
  20         }
  21         if (normalize_path_copy(sanitized, sanitized))
  22                 goto error_out;
  23         if (is_absolute_path(orig)) {
  24                 size_t root_len, len, total;
  25                 const char *work_tree = get_git_work_tree();
  26                 if (!work_tree)
  27                         goto error_out;
  28                 len = strlen(work_tree);
  29                 root_len = offset_1st_component(work_tree);
  30                 total = strlen(sanitized) + 1;
  31                 if (strncmp(sanitized, work_tree, len) ||
  32                     (len > root_len && sanitized[len] != '\0' && sanitized[len] != '/')) {
  33                 error_out:
  34                         die("'%s' is outside repository", orig);
  35                 }
  36                 if (sanitized[len] == '/')
  37                         len++;
  38                 memmove(sanitized, sanitized + len, total - len);
  39         }
  40         return sanitized;
  41 }
  42
  43 /*
  44  * Unlike prefix_path, this should be used if the named file does
  45  * not have to interact with index entry; i.e. name of a random file
  46  * on the filesystem.
  47  */
  48 const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
  49 {
  50         static char path[PATH_MAX];
  51 #ifndef WIN32
  52         if (!pfx_len || is_absolute_path(arg))
  53                 return arg;
  54         memcpy(path, pfx, pfx_len);
  55         strcpy(path + pfx_len, arg);
  56 #else
  57         char *p;
  58         /* don't add prefix to absolute paths, but still replace '\' by '/' */
  59         if (is_absolute_path(arg))
  60                 pfx_len = 0;
  61         else if (pfx_len)
  62                 memcpy(path, pfx, pfx_len);
  63         strcpy(path + pfx_len, arg);
  64         for (p = path + pfx_len; *p; p++)
  65                 if (*p == '\\')
  66                         *p = '/';
  67 #endif
  68         return path;
  69 }
  70
  71 int check_filename(const char *prefix, const char *arg)
  72 {
  73         const char *name;
  74         struct stat st;
  75
  76         name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
  77         if (!lstat(name, &st))
  78                 return 1; /* file exists */
  79         if (errno == ENOENT || errno == ENOTDIR)
  80                 return 0; /* file does not exist */
  81         die_errno("failed to stat '%s'", arg);
  82 }
  83
  84 static void NORETURN die_verify_filename(const char *prefix, const char *arg)
  85 {
  86         unsigned char sha1[20];
  87         unsigned mode;
  88
  89         /*
  90          * Saying "'(icase)foo' does not exist in the index" when the
  91          * user gave us ":(icase)foo" is just stupid.  A magic pathspec
  92          * begins with a colon and is followed by a non-alnum; do not
  93          * let get_sha1_with_mode_1(only_to_die=1) to even trigger.
  94          */
  95         if (!(arg[0] == ':' && !isalnum(arg[1])))
  96                 /* try a detailed diagnostic ... */
  97                 get_sha1_with_mode_1(arg, sha1, &mode, 1, prefix);
  98
  99         /* ... or fall back the most general message. */
 100         die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
 101             "Use '--' to separate paths from revisions", arg);
 102
 103 }
 104
 105 /*
 106  * Verify a filename that we got as an argument for a pathspec
 107  * entry. Note that a filename that begins with "-" never verifies
 108  * as true, because even if such a filename were to exist, we want
 109  * it to be preceded by the "--" marker (or we want the user to
 110  * use a format like "./-filename")
 111  */
 112 void verify_filename(const char *prefix, const char *arg)
 113 {
 114         if (*arg == '-')
 115                 die("bad flag '%s' used after filename", arg);
 116         if (check_filename(prefix, arg))
 117                 return;
 118         die_verify_filename(prefix, arg);
 119 }
 120
 121 /*
 122  * Opposite of the above: the command line did not have -- marker
 123  * and we parsed the arg as a refname.  It should not be interpretable
 124  * as a filename.
 125  */
 126 void verify_non_filename(const char *prefix, const char *arg)
 127 {
 128         if (!is_inside_work_tree() || is_inside_git_dir())
 129                 return;
 130         if (*arg == '-')
 131                 return; /* flag */
 132         if (!check_filename(prefix, arg))
 133                 return;
 134         die("ambiguous argument '%s': both revision and filename\n"
 135             "Use '--' to separate filenames from revisions", arg);
 136 }
 137
 138 /*
 139  * Magic pathspec
 140  *
 141  * NEEDSWORK: These need to be moved to dir.h or even to a new
 142  * pathspec.h when we restructure get_pathspec() users to use the
 143  * "struct pathspec" interface.
 144  *
 145  * Possible future magic semantics include stuff like:
 146  *
 147  *      { PATHSPEC_NOGLOB, '!', "noglob" },
 148  *      { PATHSPEC_ICASE, '\0', "icase" },
 149  *      { PATHSPEC_RECURSIVE, '*', "recursive" },
 150  *      { PATHSPEC_REGEXP, '\0', "regexp" },
 151  *
 152  */
 153 #define PATHSPEC_FROMTOP    (1<<0)
 154
 155 static struct pathspec_magic {
 156         unsigned bit;
 157         char mnemonic; /* this cannot be ':'! */
 158         const char *name;
 159 } pathspec_magic[] = {
 160         { PATHSPEC_FROMTOP, '/', "top" },
 161 };
 162
 163 /*
 164  * Take an element of a pathspec and check for magic signatures.
 165  * Append the result to the prefix.
 166  *
 167  * For now, we only parse the syntax and throw out anything other than
 168  * "top" magic.
 169  *
 170  * NEEDSWORK: This needs to be rewritten when we start migrating
 171  * get_pathspec() users to use the "struct pathspec" interface.  For
 172  * example, a pathspec element may be marked as case-insensitive, but
 173  * the prefix part must always match literally, and a single stupid
 174  * string cannot express such a case.
 175  */
 176 static const char *prefix_pathspec(const char *prefix, int prefixlen, const char *elt)
 177 {
 178         unsigned magic = 0;
 179         const char *copyfrom = elt;
 180         int i;
 181
 182         if (elt[0] != ':') {
 183                 ; /* nothing to do */
 184         } else if (elt[1] == '(') {
 185                 /* longhand */
 186                 const char *nextat;
 187                 for (copyfrom = elt + 2;
 188                      *copyfrom && *copyfrom != ')';
 189                      copyfrom = nextat) {
 190                         size_t len = strcspn(copyfrom, ",)");
 191                         if (copyfrom[len] == ')')
 192                                 nextat = copyfrom + len;
 193                         else
 194                                 nextat = copyfrom + len + 1;
 195                         if (!len)
 196                                 continue;
 197                         for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
 198                                 if (strlen(pathspec_magic[i].name) == len &&
 199                                     !strncmp(pathspec_magic[i].name, copyfrom, len)) {
 200                                         magic |= pathspec_magic[i].bit;
 201                                         break;
 202                                 }
 203                         if (ARRAY_SIZE(pathspec_magic) <= i)
 204                                 die("Invalid pathspec magic '%.*s' in '%s'",
 205                                     (int) len, copyfrom, elt);
 206                 }
 207                 if (*copyfrom == ')')
 208                         copyfrom++;
 209         } else {
 210                 /* shorthand */
 211                 for (copyfrom = elt + 1;
 212                      *copyfrom && *copyfrom != ':';
 213                      copyfrom++) {
 214                         char ch = *copyfrom;
 215
 216                         if (!is_pathspec_magic(ch))
 217                                 break;
 218                         for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
 219                                 if (pathspec_magic[i].mnemonic == ch) {
 220                                         magic |= pathspec_magic[i].bit;
 221                                         break;
 222                                 }
 223                         if (ARRAY_SIZE(pathspec_magic) <= i)
 224                                 die("Unimplemented pathspec magic '%c' in '%s'",
 225                                     ch, elt);
 226                 }
 227                 if (*copyfrom == ':')
 228                         copyfrom++;
 229         }
 230
 231         if (magic & PATHSPEC_FROMTOP)
 232                 return xstrdup(copyfrom);
 233         else
 234                 return prefix_path(prefix, prefixlen, copyfrom);
 235 }
 236
 237 const char **get_pathspec(const char *prefix, const char **pathspec)
 238 {
 239         const char *entry = *pathspec;
 240         const char **src, **dst;
 241         int prefixlen;
 242
 243         if (!prefix && !entry)
 244                 return NULL;
 245
 246         if (!entry) {
 247                 static const char *spec[2];
 248                 spec[0] = prefix;
 249                 spec[1] = NULL;
 250                 return spec;
 251         }
 252
 253         /* Otherwise we have to re-write the entries.. */
 254         src = pathspec;
 255         dst = pathspec;
 256         prefixlen = prefix ? strlen(prefix) : 0;
 257         while (*src) {
 258                 *(dst++) = prefix_pathspec(prefix, prefixlen, *src);
 259                 src++;
 260         }
 261         *dst = NULL;
 262         if (!*pathspec)
 263                 return NULL;
 264         return pathspec;
 265 }
 266
 267 const char *pathspec_prefix(const char *prefix, const char **pathspec)
 268 {
 269         const char **p, *n, *prev;
 270         unsigned long max;
 271
 272         if (!pathspec)
 273                 return prefix ? xmemdupz(prefix, strlen(prefix)) : NULL;
 274
 275         prev = NULL;
 276         max = PATH_MAX;
 277         for (p = pathspec; (n = *p) != NULL; p++) {
 278                 int i, len = 0;
 279                 for (i = 0; i < max; i++) {
 280                         char c = n[i];
 281                         if (prev && prev[i] != c)
 282                                 break;
 283                         if (!c || c == '*' || c == '?')
 284                                 break;
 285                         if (c == '/')
 286                                 len = i+1;
 287                 }
 288                 prev = n;
 289                 if (len < max) {
 290                         max = len;
 291                         if (!max)
 292                                 break;
 293                 }
 294         }
 295
 296         return max ? xmemdupz(prev, max) : NULL;
 297 }
 298
 299 /*
 300  * Test if it looks like we're at a git directory.
 301  * We want to see:
 302  *
 303  *  - either an objects/ directory _or_ the proper
 304  *    GIT_OBJECT_DIRECTORY environment variable
 305  *  - a refs/ directory
 306  *  - either a HEAD symlink or a HEAD file that is formatted as
 307  *    a proper "ref:", or a regular file HEAD that has a properly
 308  *    formatted sha1 object name.
 309  */
 310 static int is_git_directory(const char *suspect)
 311 {
 312         char path[PATH_MAX];
 313         size_t len = strlen(suspect);
 314
 315         if (PATH_MAX <= len + strlen("/objects"))
 316                 die("Too long path: %.*s", 60, suspect);
 317         strcpy(path, suspect);
 318         if (getenv(DB_ENVIRONMENT)) {
 319                 if (access(getenv(DB_ENVIRONMENT), X_OK))
 320                         return 0;
 321         }
 322         else {
 323                 strcpy(path + len, "/objects");
 324                 if (access(path, X_OK))
 325                         return 0;
 326         }
 327
 328         strcpy(path + len, "/refs");
 329         if (access(path, X_OK))
 330                 return 0;
 331
 332         strcpy(path + len, "/HEAD");
 333         if (validate_headref(path))
 334                 return 0;
 335
 336         return 1;
 337 }
 338
 339 int is_inside_git_dir(void)
 340 {
 341         if (inside_git_dir < 0)
 342                 inside_git_dir = is_inside_dir(get_git_dir());
 343         return inside_git_dir;
 344 }
 345
 346 int is_inside_work_tree(void)
 347 {
 348         if (inside_work_tree < 0)
 349                 inside_work_tree = is_inside_dir(get_git_work_tree());
 350         return inside_work_tree;
 351 }
 352
 353 void setup_work_tree(void)
 354 {
 355         const char *work_tree, *git_dir;
 356         static int initialized = 0;
 357
 358         if (initialized)
 359                 return;
 360         work_tree = get_git_work_tree();
 361         git_dir = get_git_dir();
 362         if (!is_absolute_path(git_dir))
 363                 git_dir = real_path(get_git_dir());
 364         if (!work_tree || chdir(work_tree))
 365                 die("This operation must be run in a work tree");
 366
 367         /*
 368          * Make sure subsequent git processes find correct worktree
 369          * if $GIT_WORK_TREE is set relative
 370          */
 371         if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 372                 setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 373
 374         set_git_dir(relative_path(git_dir, work_tree));
 375         initialized = 1;
 376 }
 377
 378 static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 379 {
 380         char repo_config[PATH_MAX+1];
 381
 382         /*
 383          * git_config() can't be used here because it calls git_pathdup()
 384          * to get $GIT_CONFIG/config. That call will make setup_git_env()
 385          * set git_dir to ".git".
 386          *
 387          * We are in gitdir setup, no git dir has been found useable yet.
 388          * Use a gentler version of git_config() to check if this repo
 389          * is a good one.
 390          */
 391         snprintf(repo_config, PATH_MAX, "%s/config", gitdir);
 392         git_config_early(check_repository_format_version, NULL, repo_config);
 393         if (GIT_REPO_VERSION < repository_format_version) {
 394                 if (!nongit_ok)
 395                         die ("Expected git repo version <= %d, found %d",
 396                              GIT_REPO_VERSION, repository_format_version);
 397                 warning("Expected git repo version <= %d, found %d",
 398                         GIT_REPO_VERSION, repository_format_version);
 399                 warning("Please upgrade Git");
 400                 *nongit_ok = -1;
 401                 return -1;
 402         }
 403         return 0;
 404 }
 405
 406 /*
 407  * Try to read the location of the git directory from the .git file,
 408  * return path to git directory if found.
 409  */
 410 const char *read_gitfile_gently(const char *path)
 411 {
 412         char *buf;
 413         char *dir;
 414         const char *slash;
 415         struct stat st;
 416         int fd;
 417         ssize_t len;
 418
 419         if (stat(path, &st))
 420                 return NULL;
 421         if (!S_ISREG(st.st_mode))
 422                 return NULL;
 423         fd = open(path, O_RDONLY);
 424         if (fd < 0)
 425                 die_errno("Error opening '%s'", path);
 426         buf = xmalloc(st.st_size + 1);
 427         len = read_in_full(fd, buf, st.st_size);
 428         close(fd);
 429         if (len != st.st_size)
 430                 die("Error reading %s", path);
 431         buf[len] = '\0';
 432         if (prefixcmp(buf, "gitdir: "))
 433                 die("Invalid gitfile format: %s", path);
 434         while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 435                 len--;
 436         if (len < 9)
 437                 die("No path in gitfile: %s", path);
 438         buf[len] = '\0';
 439         dir = buf + 8;
 440
 441         if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
 442                 size_t pathlen = slash+1 - path;
 443                 size_t dirlen = pathlen + len - 8;
 444                 dir = xmalloc(dirlen + 1);
 445                 strncpy(dir, path, pathlen);
 446                 strncpy(dir + pathlen, buf + 8, len - 8);
 447                 dir[dirlen] = '\0';
 448                 free(buf);
 449                 buf = dir;
 450         }
 451
 452         if (!is_git_directory(dir))
 453                 die("Not a git repository: %s", dir);
 454         path = real_path(dir);
 455
 456         free(buf);
 457         return path;
 458 }
 459
 460 static const char *setup_explicit_git_dir(const char *gitdirenv,
 461                                           char *cwd, int len,
 462                                           int *nongit_ok)
 463 {
 464         const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 465         const char *worktree;
 466         char *gitfile;
 467         int offset;
 468
 469         if (PATH_MAX - 40 < strlen(gitdirenv))
 470                 die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 471
 472         gitfile = (char*)read_gitfile_gently(gitdirenv);
 473         if (gitfile) {
 474                 gitfile = xstrdup(gitfile);
 475                 gitdirenv = gitfile;
 476         }
 477
 478         if (!is_git_directory(gitdirenv)) {
 479                 if (nongit_ok) {
 480                         *nongit_ok = 1;
 481                         free(gitfile);
 482                         return NULL;
 483                 }
 484                 die("Not a git repository: '%s'", gitdirenv);
 485         }
 486
 487         if (check_repository_format_gently(gitdirenv, nongit_ok)) {
 488                 free(gitfile);
 489                 return NULL;
 490         }
 491
 492         /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
 493         if (work_tree_env)
 494                 set_git_work_tree(work_tree_env);
 495         else if (is_bare_repository_cfg > 0) {
 496                 if (git_work_tree_cfg) /* #22.2, #30 */
 497                         die("core.bare and core.worktree do not make sense");
 498
 499                 /* #18, #26 */
 500                 set_git_dir(gitdirenv);
 501                 free(gitfile);
 502                 return NULL;
 503         }
 504         else if (git_work_tree_cfg) { /* #6, #14 */
 505                 if (is_absolute_path(git_work_tree_cfg))
 506                         set_git_work_tree(git_work_tree_cfg);
 507                 else {
 508                         char core_worktree[PATH_MAX];
 509                         if (chdir(gitdirenv))
 510                                 die_errno("Could not chdir to '%s'", gitdirenv);
 511                         if (chdir(git_work_tree_cfg))
 512                                 die_errno("Could not chdir to '%s'", git_work_tree_cfg);
 513                         if (!getcwd(core_worktree, PATH_MAX))
 514                                 die_errno("Could not get directory '%s'", git_work_tree_cfg);
 515                         if (chdir(cwd))
 516                                 die_errno("Could not come back to cwd");
 517                         set_git_work_tree(core_worktree);
 518                 }
 519         }
 520         else /* #2, #10 */
 521                 set_git_work_tree(".");
 522
 523         /* set_git_work_tree() must have been called by now */
 524         worktree = get_git_work_tree();
 525
 526         /* both get_git_work_tree() and cwd are already normalized */
 527         if (!strcmp(cwd, worktree)) { /* cwd == worktree */
 528                 set_git_dir(gitdirenv);
 529                 free(gitfile);
 530                 return NULL;
 531         }
 532
 533         offset = dir_inside_of(cwd, worktree);
 534         if (offset >= 0) {      /* cwd inside worktree? */
 535                 set_git_dir(real_path(gitdirenv));
 536                 if (chdir(worktree))
 537                         die_errno("Could not chdir to '%s'", worktree);
 538                 cwd[len++] = '/';
 539                 cwd[len] = '\0';
 540                 free(gitfile);
 541                 return cwd + offset;
 542         }
 543
 544         /* cwd outside worktree */
 545         set_git_dir(gitdirenv);
 546         free(gitfile);
 547         return NULL;
 548 }
 549
 550 static const char *setup_discovered_git_dir(const char *gitdir,
 551                                             char *cwd, int offset, int len,
 552                                             int *nongit_ok)
 553 {
 554         if (check_repository_format_gently(gitdir, nongit_ok))
 555                 return NULL;
 556
 557         /* --work-tree is set without --git-dir; use discovered one */
 558         if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 559                 if (offset != len && !is_absolute_path(gitdir))
 560                         gitdir = xstrdup(real_path(gitdir));
 561                 if (chdir(cwd))
 562                         die_errno("Could not come back to cwd");
 563                 return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
 564         }
 565
 566         /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 567         if (is_bare_repository_cfg > 0) {
 568                 set_git_dir(offset == len ? gitdir : real_path(gitdir));
 569                 if (chdir(cwd))
 570                         die_errno("Could not come back to cwd");
 571                 return NULL;
 572         }
 573
 574         /* #0, #1, #5, #8, #9, #12, #13 */
 575         set_git_work_tree(".");
 576         if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
 577                 set_git_dir(gitdir);
 578         inside_git_dir = 0;
 579         inside_work_tree = 1;
 580         if (offset == len)
 581                 return NULL;
 582
 583         /* Make "offset" point to past the '/', and add a '/' at the end */
 584         offset++;
 585         cwd[len++] = '/';
 586         cwd[len] = 0;
 587         return cwd + offset;
 588 }
 589
 590 /* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
 591 static const char *setup_bare_git_dir(char *cwd, int offset, int len, int *nongit_ok)
 592 {
 593         int root_len;
 594
 595         if (check_repository_format_gently(".", nongit_ok))
 596                 return NULL;
 597
 598         /* --work-tree is set without --git-dir; use discovered one */
 599         if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 600                 const char *gitdir;
 601
 602                 gitdir = offset == len ? "." : xmemdupz(cwd, offset);
 603                 if (chdir(cwd))
 604                         die_errno("Could not come back to cwd");
 605                 return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
 606         }
 607
 608         inside_git_dir = 1;
 609         inside_work_tree = 0;
 610         if (offset != len) {
 611                 if (chdir(cwd))
 612                         die_errno("Cannot come back to cwd");
 613                 root_len = offset_1st_component(cwd);
 614                 cwd[offset > root_len ? offset : root_len] = '\0';
 615                 set_git_dir(cwd);
 616         }
 617         else
 618                 set_git_dir(".");
 619         return NULL;
 620 }
 621
 622 static const char *setup_nongit(const char *cwd, int *nongit_ok)
 623 {
 624         if (!nongit_ok)
 625                 die("Not a git repository (or any of the parent directories): %s", DEFAULT_GIT_DIR_ENVIRONMENT);
 626         if (chdir(cwd))
 627                 die_errno("Cannot come back to cwd");
 628         *nongit_ok = 1;
 629         return NULL;
 630 }
 631
 632 static dev_t get_device_or_die(const char *path, const char *prefix)
 633 {
 634         struct stat buf;
 635         if (stat(path, &buf))
 636                 die_errno("failed to stat '%s%s%s'",
 637                                 prefix ? prefix : "",
 638                                 prefix ? "/" : "", path);
 639         return buf.st_dev;
 640 }
 641
 642 /*
 643  * We cannot decide in this function whether we are in the work tree or
 644  * not, since the config can only be read _after_ this function was called.
 645  */
 646 static const char *setup_git_directory_gently_1(int *nongit_ok)
 647 {
 648         const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 649         static char cwd[PATH_MAX+1];
 650         const char *gitdirenv, *ret;
 651         char *gitfile;
 652         int len, offset, ceil_offset;
 653         dev_t current_device = 0;
 654         int one_filesystem = 1;
 655
 656         /*
 657          * Let's assume that we are in a git repository.
 658          * If it turns out later that we are somewhere else, the value will be
 659          * updated accordingly.
 660          */
 661         if (nongit_ok)
 662                 *nongit_ok = 0;
 663
 664         if (!getcwd(cwd, sizeof(cwd)-1))
 665                 die_errno("Unable to read current working directory");
 666         offset = len = strlen(cwd);
 667
 668         /*
 669          * If GIT_DIR is set explicitly, we're not going
 670          * to do any discovery, but we still do repository
 671          * validation.
 672          */
 673         gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 674         if (gitdirenv)
 675                 return setup_explicit_git_dir(gitdirenv, cwd, len, nongit_ok);
 676
 677         ceil_offset = longest_ancestor_length(cwd, env_ceiling_dirs);
 678         if (ceil_offset < 0 && has_dos_drive_prefix(cwd))
 679                 ceil_offset = 1;
 680
 681         /*
 682          * Test in the following order (relative to the cwd):
 683          * - .git (file containing "gitdir: <path>")
 684          * - .git/
 685          * - ./ (bare)
 686          * - ../.git
 687          * - ../.git/
 688          * - ../ (bare)
 689          * - ../../.git/
 690          *   etc.
 691          */
 692         one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
 693         if (one_filesystem)
 694                 current_device = get_device_or_die(".", NULL);
 695         for (;;) {
 696                 gitfile = (char*)read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
 697                 if (gitfile)
 698                         gitdirenv = gitfile = xstrdup(gitfile);
 699                 else {
 700                         if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 701                                 gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
 702                 }
 703
 704                 if (gitdirenv) {
 705                         ret = setup_discovered_git_dir(gitdirenv,
 706                                                        cwd, offset, len,
 707                                                        nongit_ok);
 708                         free(gitfile);
 709                         return ret;
 710                 }
 711                 free(gitfile);
 712
 713                 if (is_git_directory("."))
 714                         return setup_bare_git_dir(cwd, offset, len, nongit_ok);
 715
 716                 while (--offset > ceil_offset && cwd[offset] != '/');
 717                 if (offset <= ceil_offset)
 718                         return setup_nongit(cwd, nongit_ok);
 719                 if (one_filesystem) {
 720                         dev_t parent_device = get_device_or_die("..", cwd);
 721                         if (parent_device != current_device) {
 722                                 if (nongit_ok) {
 723                                         if (chdir(cwd))
 724                                                 die_errno("Cannot come back to cwd");
 725                                         *nongit_ok = 1;
 726                                         return NULL;
 727                                 }
 728                                 cwd[offset] = '\0';
 729                                 die("Not a git repository (or any parent up to mount parent %s)\n"
 730                                 "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).", cwd);
 731                         }
 732                 }
 733                 if (chdir("..")) {
 734                         cwd[offset] = '\0';
 735                         die_errno("Cannot change to '%s/..'", cwd);
 736                 }
 737         }
 738 }
 739
 740 const char *setup_git_directory_gently(int *nongit_ok)
 741 {
 742         const char *prefix;
 743
 744         prefix = setup_git_directory_gently_1(nongit_ok);
 745         if (prefix)
 746                 setenv("GIT_PREFIX", prefix, 1);
 747         else
 748                 setenv("GIT_PREFIX", "", 1);
 749
 750         if (startup_info) {
 751                 startup_info->have_repository = !nongit_ok || !*nongit_ok;
 752                 startup_info->prefix = prefix;
 753         }
 754         return prefix;
 755 }
 756
 757 int git_config_perm(const char *var, const char *value)
 758 {
 759         int i;
 760         char *endptr;
 761
 762         if (value == NULL)
 763                 return PERM_GROUP;
 764
 765         if (!strcmp(value, "umask"))
 766                 return PERM_UMASK;
 767         if (!strcmp(value, "group"))
 768                 return PERM_GROUP;
 769         if (!strcmp(value, "all") ||
 770             !strcmp(value, "world") ||
 771             !strcmp(value, "everybody"))
 772                 return PERM_EVERYBODY;
 773
 774         /* Parse octal numbers */
 775         i = strtol(value, &endptr, 8);
 776
 777         /* If not an octal number, maybe true/false? */
 778         if (*endptr != 0)
 779                 return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
 780
 781         /*
 782          * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
 783          * a chmod value to restrict to.
 784          */
 785         switch (i) {
 786         case PERM_UMASK:               /* 0 */
 787                 return PERM_UMASK;
 788         case OLD_PERM_GROUP:           /* 1 */
 789                 return PERM_GROUP;
 790         case OLD_PERM_EVERYBODY:       /* 2 */
 791                 return PERM_EVERYBODY;
 792         }
 793
 794         /* A filemode value was given: 0xxx */
 795
 796         if ((i & 0600) != 0600)
 797                 die("Problem with core.sharedRepository filemode value "
 798                     "(0%.3o).\nThe owner of files must always have "
 799                     "read and write permissions.", i);
 800
 801         /*
 802          * Mask filemode value. Others can not get write permission.
 803          * x flags for directories are handled separately.
 804          */
 805         return -(i & 0666);
 806 }
 807
 808 int check_repository_format_version(const char *var, const char *value, void *cb)
 809 {
 810         if (strcmp(var, "core.repositoryformatversion") == 0)
 811                 repository_format_version = git_config_int(var, value);
 812         else if (strcmp(var, "core.sharedrepository") == 0)
 813                 shared_repository = git_config_perm(var, value);
 814         else if (strcmp(var, "core.bare") == 0) {
 815                 is_bare_repository_cfg = git_config_bool(var, value);
 816                 if (is_bare_repository_cfg == 1)
 817                         inside_work_tree = -1;
 818         } else if (strcmp(var, "core.worktree") == 0) {
 819                 if (!value)
 820                         return config_error_nonbool(var);
 821                 free(git_work_tree_cfg);
 822                 git_work_tree_cfg = xstrdup(value);
 823                 inside_work_tree = -1;
 824         }
 825         return 0;
 826 }
 827
 828 int check_repository_format(void)
 829 {
 830         return check_repository_format_gently(get_git_dir(), NULL);
 831 }
 832
 833 /*
 834  * Returns the "prefix", a path to the current working directory
 835  * relative to the work tree root, or NULL, if the current working
 836  * directory is not a strict subdirectory of the work tree root. The
 837  * prefix always ends with a '/' character.
 838  */
 839 const char *setup_git_directory(void)
 840 {
 841         return setup_git_directory_gently(NULL);
 842 }