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 int check_filename(const char *prefix, const char *arg)
  44 {
  45         const char *name;
  46         struct stat st;
  47
  48         name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
  49         if (!lstat(name, &st))
  50                 return 1; /* file exists */
  51         if (errno == ENOENT || errno == ENOTDIR)
  52                 return 0; /* file does not exist */
  53         die_errno("failed to stat '%s'", arg);
  54 }
  55
  56 static void NORETURN die_verify_filename(const char *prefix,
  57                                          const char *arg,
  58                                          int diagnose_misspelt_rev)
  59 {
  60         unsigned char sha1[20];
  61         unsigned mode;
  62
  63         if (!diagnose_misspelt_rev)
  64                 die("%s: no such path in the working tree.\n"
  65                     "Use '-- <path>...' to specify paths that do not exist locally.",
  66                     arg);
  67         /*
  68          * Saying "'(icase)foo' does not exist in the index" when the
  69          * user gave us ":(icase)foo" is just stupid.  A magic pathspec
  70          * begins with a colon and is followed by a non-alnum; do not
  71          * let get_sha1_with_mode_1(only_to_die=1) to even trigger.
  72          */
  73         if (!(arg[0] == ':' && !isalnum(arg[1])))
  74                 /* try a detailed diagnostic ... */
  75                 get_sha1_with_mode_1(arg, sha1, &mode, 1, prefix);
  76
  77         /* ... or fall back the most general message. */
  78         die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
  79             "Use '--' to separate paths from revisions", arg);
  80
  81 }
  82
  83 /*
  84  * Verify a filename that we got as an argument for a pathspec
  85  * entry. Note that a filename that begins with "-" never verifies
  86  * as true, because even if such a filename were to exist, we want
  87  * it to be preceded by the "--" marker (or we want the user to
  88  * use a format like "./-filename")
  89  *
  90  * The "diagnose_misspelt_rev" is used to provide a user-friendly
  91  * diagnosis when dying upon finding that "name" is not a pathname.
  92  * If set to 1, the diagnosis will try to diagnose "name" as an
  93  * invalid object name (e.g. HEAD:foo). If set to 0, the diagnosis
  94  * will only complain about an inexisting file.
  95  *
  96  * This function is typically called to check that a "file or rev"
  97  * argument is unambiguous. In this case, the caller will want
  98  * diagnose_misspelt_rev == 1 when verifying the first non-rev
  99  * argument (which could have been a revision), and
 100  * diagnose_misspelt_rev == 0 for the next ones (because we already
 101  * saw a filename, there's not ambiguity anymore).
 102  */
 103 void verify_filename(const char *prefix,
 104                      const char *arg,
 105                      int diagnose_misspelt_rev)
 106 {
 107         if (*arg == '-')
 108                 die("bad flag '%s' used after filename", arg);
 109         if (check_filename(prefix, arg))
 110                 return;
 111         die_verify_filename(prefix, arg, diagnose_misspelt_rev);
 112 }
 113
 114 /*
 115  * Opposite of the above: the command line did not have -- marker
 116  * and we parsed the arg as a refname.  It should not be interpretable
 117  * as a filename.
 118  */
 119 void verify_non_filename(const char *prefix, const char *arg)
 120 {
 121         if (!is_inside_work_tree() || is_inside_git_dir())
 122                 return;
 123         if (*arg == '-')
 124                 return; /* flag */
 125         if (!check_filename(prefix, arg))
 126                 return;
 127         die("ambiguous argument '%s': both revision and filename\n"
 128             "Use '--' to separate filenames from revisions", arg);
 129 }
 130
 131 /*
 132  * Magic pathspec
 133  *
 134  * NEEDSWORK: These need to be moved to dir.h or even to a new
 135  * pathspec.h when we restructure get_pathspec() users to use the
 136  * "struct pathspec" interface.
 137  *
 138  * Possible future magic semantics include stuff like:
 139  *
 140  *      { PATHSPEC_NOGLOB, '!', "noglob" },
 141  *      { PATHSPEC_ICASE, '\0', "icase" },
 142  *      { PATHSPEC_RECURSIVE, '*', "recursive" },
 143  *      { PATHSPEC_REGEXP, '\0', "regexp" },
 144  *
 145  */
 146 #define PATHSPEC_FROMTOP    (1<<0)
 147
 148 static struct pathspec_magic {
 149         unsigned bit;
 150         char mnemonic; /* this cannot be ':'! */
 151         const char *name;
 152 } pathspec_magic[] = {
 153         { PATHSPEC_FROMTOP, '/', "top" },
 154 };
 155
 156 /*
 157  * Take an element of a pathspec and check for magic signatures.
 158  * Append the result to the prefix.
 159  *
 160  * For now, we only parse the syntax and throw out anything other than
 161  * "top" magic.
 162  *
 163  * NEEDSWORK: This needs to be rewritten when we start migrating
 164  * get_pathspec() users to use the "struct pathspec" interface.  For
 165  * example, a pathspec element may be marked as case-insensitive, but
 166  * the prefix part must always match literally, and a single stupid
 167  * string cannot express such a case.
 168  */
 169 static const char *prefix_pathspec(const char *prefix, int prefixlen, const char *elt)
 170 {
 171         unsigned magic = 0;
 172         const char *copyfrom = elt;
 173         int i;
 174
 175         if (elt[0] != ':') {
 176                 ; /* nothing to do */
 177         } else if (elt[1] == '(') {
 178                 /* longhand */
 179                 const char *nextat;
 180                 for (copyfrom = elt + 2;
 181                      *copyfrom && *copyfrom != ')';
 182                      copyfrom = nextat) {
 183                         size_t len = strcspn(copyfrom, ",)");
 184                         if (copyfrom[len] == ')')
 185                                 nextat = copyfrom + len;
 186                         else
 187                                 nextat = copyfrom + len + 1;
 188                         if (!len)
 189                                 continue;
 190                         for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
 191                                 if (strlen(pathspec_magic[i].name) == len &&
 192                                     !strncmp(pathspec_magic[i].name, copyfrom, len)) {
 193                                         magic |= pathspec_magic[i].bit;
 194                                         break;
 195                                 }
 196                         if (ARRAY_SIZE(pathspec_magic) <= i)
 197                                 die("Invalid pathspec magic '%.*s' in '%s'",
 198                                     (int) len, copyfrom, elt);
 199                 }
 200                 if (*copyfrom == ')')
 201                         copyfrom++;
 202         } else {
 203                 /* shorthand */
 204                 for (copyfrom = elt + 1;
 205                      *copyfrom && *copyfrom != ':';
 206                      copyfrom++) {
 207                         char ch = *copyfrom;
 208
 209                         if (!is_pathspec_magic(ch))
 210                                 break;
 211                         for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
 212                                 if (pathspec_magic[i].mnemonic == ch) {
 213                                         magic |= pathspec_magic[i].bit;
 214                                         break;
 215                                 }
 216                         if (ARRAY_SIZE(pathspec_magic) <= i)
 217                                 die("Unimplemented pathspec magic '%c' in '%s'",
 218                                     ch, elt);
 219                 }
 220                 if (*copyfrom == ':')
 221                         copyfrom++;
 222         }
 223
 224         if (magic & PATHSPEC_FROMTOP)
 225                 return xstrdup(copyfrom);
 226         else
 227                 return prefix_path(prefix, prefixlen, copyfrom);
 228 }
 229
 230 const char **get_pathspec(const char *prefix, const char **pathspec)
 231 {
 232         const char *entry = *pathspec;
 233         const char **src, **dst;
 234         int prefixlen;
 235
 236         if (!prefix && !entry)
 237                 return NULL;
 238
 239         if (!entry) {
 240                 static const char *spec[2];
 241                 spec[0] = prefix;
 242                 spec[1] = NULL;
 243                 return spec;
 244         }
 245
 246         /* Otherwise we have to re-write the entries.. */
 247         src = pathspec;
 248         dst = pathspec;
 249         prefixlen = prefix ? strlen(prefix) : 0;
 250         while (*src) {
 251                 *(dst++) = prefix_pathspec(prefix, prefixlen, *src);
 252                 src++;
 253         }
 254         *dst = NULL;
 255         if (!*pathspec)
 256                 return NULL;
 257         return pathspec;
 258 }
 259
 260 /*
 261  * Test if it looks like we're at a git directory.
 262  * We want to see:
 263  *
 264  *  - either an objects/ directory _or_ the proper
 265  *    GIT_OBJECT_DIRECTORY environment variable
 266  *  - a refs/ directory
 267  *  - either a HEAD symlink or a HEAD file that is formatted as
 268  *    a proper "ref:", or a regular file HEAD that has a properly
 269  *    formatted sha1 object name.
 270  */
 271 int is_git_directory(const char *suspect)
 272 {
 273         char path[PATH_MAX];
 274         size_t len = strlen(suspect);
 275
 276         if (PATH_MAX <= len + strlen("/objects"))
 277                 die("Too long path: %.*s", 60, suspect);
 278         strcpy(path, suspect);
 279         if (getenv(DB_ENVIRONMENT)) {
 280                 if (access(getenv(DB_ENVIRONMENT), X_OK))
 281                         return 0;
 282         }
 283         else {
 284                 strcpy(path + len, "/objects");
 285                 if (access(path, X_OK))
 286                         return 0;
 287         }
 288
 289         strcpy(path + len, "/refs");
 290         if (access(path, X_OK))
 291                 return 0;
 292
 293         strcpy(path + len, "/HEAD");
 294         if (validate_headref(path))
 295                 return 0;
 296
 297         return 1;
 298 }
 299
 300 int is_inside_git_dir(void)
 301 {
 302         if (inside_git_dir < 0)
 303                 inside_git_dir = is_inside_dir(get_git_dir());
 304         return inside_git_dir;
 305 }
 306
 307 int is_inside_work_tree(void)
 308 {
 309         if (inside_work_tree < 0)
 310                 inside_work_tree = is_inside_dir(get_git_work_tree());
 311         return inside_work_tree;
 312 }
 313
 314 void setup_work_tree(void)
 315 {
 316         const char *work_tree, *git_dir;
 317         static int initialized = 0;
 318
 319         if (initialized)
 320                 return;
 321         work_tree = get_git_work_tree();
 322         git_dir = get_git_dir();
 323         if (!is_absolute_path(git_dir))
 324                 git_dir = real_path(get_git_dir());
 325         if (!work_tree || chdir(work_tree))
 326                 die("This operation must be run in a work tree");
 327
 328         /*
 329          * Make sure subsequent git processes find correct worktree
 330          * if $GIT_WORK_TREE is set relative
 331          */
 332         if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 333                 setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 334
 335         set_git_dir(relative_path(git_dir, work_tree));
 336         initialized = 1;
 337 }
 338
 339 static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 340 {
 341         char repo_config[PATH_MAX+1];
 342
 343         /*
 344          * git_config() can't be used here because it calls git_pathdup()
 345          * to get $GIT_CONFIG/config. That call will make setup_git_env()
 346          * set git_dir to ".git".
 347          *
 348          * We are in gitdir setup, no git dir has been found useable yet.
 349          * Use a gentler version of git_config() to check if this repo
 350          * is a good one.
 351          */
 352         snprintf(repo_config, PATH_MAX, "%s/config", gitdir);
 353         git_config_early(check_repository_format_version, NULL, repo_config);
 354         if (GIT_REPO_VERSION < repository_format_version) {
 355                 if (!nongit_ok)
 356                         die ("Expected git repo version <= %d, found %d",
 357                              GIT_REPO_VERSION, repository_format_version);
 358                 warning("Expected git repo version <= %d, found %d",
 359                         GIT_REPO_VERSION, repository_format_version);
 360                 warning("Please upgrade Git");
 361                 *nongit_ok = -1;
 362                 return -1;
 363         }
 364         return 0;
 365 }
 366
 367 /*
 368  * Try to read the location of the git directory from the .git file,
 369  * return path to git directory if found.
 370  */
 371 const char *read_gitfile(const char *path)
 372 {
 373         char *buf;
 374         char *dir;
 375         const char *slash;
 376         struct stat st;
 377         int fd;
 378         ssize_t len;
 379
 380         if (stat(path, &st))
 381                 return NULL;
 382         if (!S_ISREG(st.st_mode))
 383                 return NULL;
 384         fd = open(path, O_RDONLY);
 385         if (fd < 0)
 386                 die_errno("Error opening '%s'", path);
 387         buf = xmalloc(st.st_size + 1);
 388         len = read_in_full(fd, buf, st.st_size);
 389         close(fd);
 390         if (len != st.st_size)
 391                 die("Error reading %s", path);
 392         buf[len] = '\0';
 393         if (prefixcmp(buf, "gitdir: "))
 394                 die("Invalid gitfile format: %s", path);
 395         while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 396                 len--;
 397         if (len < 9)
 398                 die("No path in gitfile: %s", path);
 399         buf[len] = '\0';
 400         dir = buf + 8;
 401
 402         if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
 403                 size_t pathlen = slash+1 - path;
 404                 size_t dirlen = pathlen + len - 8;
 405                 dir = xmalloc(dirlen + 1);
 406                 strncpy(dir, path, pathlen);
 407                 strncpy(dir + pathlen, buf + 8, len - 8);
 408                 dir[dirlen] = '\0';
 409                 free(buf);
 410                 buf = dir;
 411         }
 412
 413         if (!is_git_directory(dir))
 414                 die("Not a git repository: %s", dir);
 415         path = real_path(dir);
 416
 417         free(buf);
 418         return path;
 419 }
 420
 421 static const char *setup_explicit_git_dir(const char *gitdirenv,
 422                                           char *cwd, int len,
 423                                           int *nongit_ok)
 424 {
 425         const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 426         const char *worktree;
 427         char *gitfile;
 428         int offset;
 429
 430         if (PATH_MAX - 40 < strlen(gitdirenv))
 431                 die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 432
 433         gitfile = (char*)read_gitfile(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         offset = dir_inside_of(cwd, worktree);
 495         if (offset >= 0) {      /* 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 + offset;
 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, int prefix_len)
 594 {
 595         struct stat buf;
 596         if (stat(path, &buf)) {
 597                 die_errno("failed to stat '%*s%s%s'",
 598                                 prefix_len,
 599                                 prefix ? prefix : "",
 600                                 prefix ? "/" : "", path);
 601         }
 602         return buf.st_dev;
 603 }
 604
 605 /*
 606  * We cannot decide in this function whether we are in the work tree or
 607  * not, since the config can only be read _after_ this function was called.
 608  */
 609 static const char *setup_git_directory_gently_1(int *nongit_ok)
 610 {
 611         const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 612         static char cwd[PATH_MAX+1];
 613         const char *gitdirenv, *ret;
 614         char *gitfile;
 615         int len, offset, offset_parent, ceil_offset;
 616         dev_t current_device = 0;
 617         int one_filesystem = 1;
 618
 619         /*
 620          * Let's assume that we are in a git repository.
 621          * If it turns out later that we are somewhere else, the value will be
 622          * updated accordingly.
 623          */
 624         if (nongit_ok)
 625                 *nongit_ok = 0;
 626
 627         if (!getcwd(cwd, sizeof(cwd)-1))
 628                 die_errno("Unable to read current working directory");
 629         offset = len = strlen(cwd);
 630
 631         /*
 632          * If GIT_DIR is set explicitly, we're not going
 633          * to do any discovery, but we still do repository
 634          * validation.
 635          */
 636         gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 637         if (gitdirenv)
 638                 return setup_explicit_git_dir(gitdirenv, cwd, len, nongit_ok);
 639
 640         ceil_offset = longest_ancestor_length(cwd, env_ceiling_dirs);
 641         if (ceil_offset < 0 && has_dos_drive_prefix(cwd))
 642                 ceil_offset = 1;
 643
 644         /*
 645          * Test in the following order (relative to the cwd):
 646          * - .git (file containing "gitdir: <path>")
 647          * - .git/
 648          * - ./ (bare)
 649          * - ../.git
 650          * - ../.git/
 651          * - ../ (bare)
 652          * - ../../.git/
 653          *   etc.
 654          */
 655         one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
 656         if (one_filesystem)
 657                 current_device = get_device_or_die(".", NULL, 0);
 658         for (;;) {
 659                 gitfile = (char*)read_gitfile(DEFAULT_GIT_DIR_ENVIRONMENT);
 660                 if (gitfile)
 661                         gitdirenv = gitfile = xstrdup(gitfile);
 662                 else {
 663                         if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 664                                 gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
 665                 }
 666
 667                 if (gitdirenv) {
 668                         ret = setup_discovered_git_dir(gitdirenv,
 669                                                        cwd, offset, len,
 670                                                        nongit_ok);
 671                         free(gitfile);
 672                         return ret;
 673                 }
 674                 free(gitfile);
 675
 676                 if (is_git_directory("."))
 677                         return setup_bare_git_dir(cwd, offset, len, nongit_ok);
 678
 679                 offset_parent = offset;
 680                 while (--offset_parent > ceil_offset && cwd[offset_parent] != '/');
 681                 if (offset_parent <= ceil_offset)
 682                         return setup_nongit(cwd, nongit_ok);
 683                 if (one_filesystem) {
 684                         dev_t parent_device = get_device_or_die("..", cwd, offset);
 685                         if (parent_device != current_device) {
 686                                 if (nongit_ok) {
 687                                         if (chdir(cwd))
 688                                                 die_errno("Cannot come back to cwd");
 689                                         *nongit_ok = 1;
 690                                         return NULL;
 691                                 }
 692                                 cwd[offset] = '\0';
 693                                 die("Not a git repository (or any parent up to mount point %s)\n"
 694                                 "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).", cwd);
 695                         }
 696                 }
 697                 if (chdir("..")) {
 698                         cwd[offset] = '\0';
 699                         die_errno("Cannot change to '%s/..'", cwd);
 700                 }
 701                 offset = offset_parent;
 702         }
 703 }
 704
 705 const char *setup_git_directory_gently(int *nongit_ok)
 706 {
 707         const char *prefix;
 708
 709         prefix = setup_git_directory_gently_1(nongit_ok);
 710         if (prefix)
 711                 setenv("GIT_PREFIX", prefix, 1);
 712         else
 713                 setenv("GIT_PREFIX", "", 1);
 714
 715         if (startup_info) {
 716                 startup_info->have_repository = !nongit_ok || !*nongit_ok;
 717                 startup_info->prefix = prefix;
 718         }
 719         return prefix;
 720 }
 721
 722 int git_config_perm(const char *var, const char *value)
 723 {
 724         int i;
 725         char *endptr;
 726
 727         if (value == NULL)
 728                 return PERM_GROUP;
 729
 730         if (!strcmp(value, "umask"))
 731                 return PERM_UMASK;
 732         if (!strcmp(value, "group"))
 733                 return PERM_GROUP;
 734         if (!strcmp(value, "all") ||
 735             !strcmp(value, "world") ||
 736             !strcmp(value, "everybody"))
 737                 return PERM_EVERYBODY;
 738
 739         /* Parse octal numbers */
 740         i = strtol(value, &endptr, 8);
 741
 742         /* If not an octal number, maybe true/false? */
 743         if (*endptr != 0)
 744                 return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
 745
 746         /*
 747          * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
 748          * a chmod value to restrict to.
 749          */
 750         switch (i) {
 751         case PERM_UMASK:               /* 0 */
 752                 return PERM_UMASK;
 753         case OLD_PERM_GROUP:           /* 1 */
 754                 return PERM_GROUP;
 755         case OLD_PERM_EVERYBODY:       /* 2 */
 756                 return PERM_EVERYBODY;
 757         }
 758
 759         /* A filemode value was given: 0xxx */
 760
 761         if ((i & 0600) != 0600)
 762                 die("Problem with core.sharedRepository filemode value "
 763                     "(0%.3o).\nThe owner of files must always have "
 764                     "read and write permissions.", i);
 765
 766         /*
 767          * Mask filemode value. Others can not get write permission.
 768          * x flags for directories are handled separately.
 769          */
 770         return -(i & 0666);
 771 }
 772
 773 int check_repository_format_version(const char *var, const char *value, void *cb)
 774 {
 775         if (strcmp(var, "core.repositoryformatversion") == 0)
 776                 repository_format_version = git_config_int(var, value);
 777         else if (strcmp(var, "core.sharedrepository") == 0)
 778                 shared_repository = git_config_perm(var, value);
 779         else if (strcmp(var, "core.bare") == 0) {
 780                 is_bare_repository_cfg = git_config_bool(var, value);
 781                 if (is_bare_repository_cfg == 1)
 782                         inside_work_tree = -1;
 783         } else if (strcmp(var, "core.worktree") == 0) {
 784                 if (!value)
 785                         return config_error_nonbool(var);
 786                 free(git_work_tree_cfg);
 787                 git_work_tree_cfg = xstrdup(value);
 788                 inside_work_tree = -1;
 789         }
 790         return 0;
 791 }
 792
 793 int check_repository_format(void)
 794 {
 795         return check_repository_format_gently(get_git_dir(), NULL);
 796 }
 797
 798 /*
 799  * Returns the "prefix", a path to the current working directory
 800  * relative to the work tree root, or NULL, if the current working
 801  * directory is not a strict subdirectory of the work tree root. The
 802  * prefix always ends with a '/' character.
 803  */
 804 const char *setup_git_directory(void)
 805 {
 806         return setup_git_directory_gently(NULL);
 807 }
 808
 809 const char *resolve_gitdir(const char *suspect)
 810 {
 811         if (is_git_directory(suspect))
 812                 return suspect;
 813         return read_gitfile(suspect);
 814 }