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