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