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