setup.c

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