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