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 /*
  44  * Unlike prefix_path, this should be used if the named file does
  45  * not have to interact with index entry; i.e. name of a random file
  46  * on the filesystem.
  47  */
  48 const char *prefix_filename(const char *pfx, int pfx_len, const char *arg)
  49 {
  50         static char path[PATH_MAX];
  51 #ifndef WIN32
  52         if (!pfx_len || is_absolute_path(arg))
  53                 return arg;
  54         memcpy(path, pfx, pfx_len);
  55         strcpy(path + pfx_len, arg);
  56 #else
  57         char *p;
  58         /* don't add prefix to absolute paths, but still replace '\' by '/' */
  59         if (is_absolute_path(arg))
  60                 pfx_len = 0;
  61         else if (pfx_len)
  62                 memcpy(path, pfx, pfx_len);
  63         strcpy(path + pfx_len, arg);
  64         for (p = path + pfx_len; *p; p++)
  65                 if (*p == '\\')
  66                         *p = '/';
  67 #endif
  68         return path;
  69 }
  70
  71 int check_filename(const char *prefix, const char *arg)
  72 {
  73         const char *name;
  74         struct stat st;
  75
  76         name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : 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, const char *arg)
  85 {
  86         unsigned char sha1[20];
  87         unsigned mode;
  88         /* try a detailed diagnostic ... */
  89         get_sha1_with_mode_1(arg, sha1, &mode, 0, prefix);
  90         /* ... or fall back the most general message. */
  91         die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
  92             "Use '--' to separate paths from revisions", arg);
  93
  94 }
  95
  96 /*
  97  * Verify a filename that we got as an argument for a pathspec
  98  * entry. Note that a filename that begins with "-" never verifies
  99  * as true, because even if such a filename were to exist, we want
 100  * it to be preceded by the "--" marker (or we want the user to
 101  * use a format like "./-filename")
 102  */
 103 void verify_filename(const char *prefix, const char *arg)
 104 {
 105         if (*arg == '-')
 106                 die("bad flag '%s' used after filename", arg);
 107         if (check_filename(prefix, arg))
 108                 return;
 109         die_verify_filename(prefix, arg);
 110 }
 111
 112 /*
 113  * Opposite of the above: the command line did not have -- marker
 114  * and we parsed the arg as a refname.  It should not be interpretable
 115  * as a filename.
 116  */
 117 void verify_non_filename(const char *prefix, const char *arg)
 118 {
 119         if (!is_inside_work_tree() || is_inside_git_dir())
 120                 return;
 121         if (*arg == '-')
 122                 return; /* flag */
 123         if (!check_filename(prefix, arg))
 124                 return;
 125         die("ambiguous argument '%s': both revision and filename\n"
 126             "Use '--' to separate filenames from revisions", arg);
 127 }
 128
 129 /*
 130  * Magic pathspec
 131  *
 132  * NEEDSWORK: These need to be moved to dir.h or even to a new
 133  * pathspec.h when we restructure get_pathspec() users to use the
 134  * "struct pathspec" interface.
 135  *
 136  * Possible future magic semantics include stuff like:
 137  *
 138  *      { PATHSPEC_NOGLOB, '!', "noglob" },
 139  *      { PATHSPEC_RECURSIVE, '*', "recursive" },
 140  *      { PATHSPEC_REGEXP, '\0', "regexp" },
 141  *
 142  */
 143 #define PATHSPEC_FROMTOP    (1<<0)
 144 #define PATHSPEC_ICASE      (1<<1)
 145
 146 struct pathspec_magic {
 147         unsigned bit;
 148         char mnemonic; /* this cannot be ':'! */
 149         const char *name;
 150 } pathspec_magic[] = {
 151         { PATHSPEC_FROMTOP, '/', "top" },
 152         { PATHSPEC_ICASE, '\0', "icase" },
 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 const char *prefix_pathspec(const char *prefix, int prefixlen, const char *elt)
 169 {
 170         unsigned magic = 0;
 171         const char *copyfrom = elt;
 172         const char *retval;
 173         int i, free_source = 0;
 174
 175         if (elt[0] != ':') {
 176                 ; /* nothing to do */
 177         } else if (elt[1] == '(') {
 178                 /* longhand */
 179                 const char *nextat;
 180                 for (copyfrom = elt + 2;
 181                      *copyfrom && *copyfrom != ')';
 182                      copyfrom = nextat) {
 183                         size_t len = strcspn(copyfrom, ",)");
 184                         if (copyfrom[len] == ')')
 185                                 nextat = copyfrom + len;
 186                         else
 187                                 nextat = copyfrom + len + 1;
 188                         if (!len)
 189                                 continue;
 190                         for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
 191                                 if (strlen(pathspec_magic[i].name) == len &&
 192                                     !strncmp(pathspec_magic[i].name, copyfrom, len)) {
 193                                         magic |= pathspec_magic[i].bit;
 194                                         break;
 195                                 }
 196                         if (ARRAY_SIZE(pathspec_magic) <= i)
 197                                 die("Invalid pathspec magic '%.*s' in '%s'",
 198                                     (int) len, copyfrom, elt);
 199                 }
 200                 if (*copyfrom == ')')
 201                         copyfrom++;
 202         } else if (!elt[1]) {
 203                 /* Just ':' -- no element! */
 204                 return NULL;
 205         } else {
 206                 /* shorthand */
 207                 for (copyfrom = elt + 1;
 208                      *copyfrom && *copyfrom != ':';
 209                      copyfrom++) {
 210                         char ch = *copyfrom;
 211
 212                         if (!is_pathspec_magic(ch))
 213                                 break;
 214                         for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
 215                                 if (pathspec_magic[i].mnemonic == ch) {
 216                                         magic |= pathspec_magic[i].bit;
 217                                         break;
 218                                 }
 219                         if (ARRAY_SIZE(pathspec_magic) <= i)
 220                                 die("Unimplemented pathspec magic '%c' in '%s'",
 221                                     ch, elt);
 222                 }
 223                 if (*copyfrom == ':')
 224                         copyfrom++;
 225         }
 226
 227         if (magic & PATHSPEC_ICASE) {
 228                 struct strbuf sb = STRBUF_INIT;
 229                 for (i = 0; copyfrom[i]; i++) {
 230                         int ch = copyfrom[i];
 231                         if (('a' <= ch && ch <= 'z') ||
 232                             ('A' <= ch && ch <= 'Z')) {
 233                                 strbuf_addf(&sb, "[%c%c]",
 234                                             tolower(ch), toupper(ch));
 235                         } else {
 236                                 strbuf_addch(&sb, ch);
 237                         }
 238                 }
 239                 if (sb.len) {
 240                         free_source = 1;
 241                         copyfrom = strbuf_detach(&sb, NULL);
 242                 }
 243         }
 244
 245         if (magic & PATHSPEC_FROMTOP)
 246                 retval = xstrdup(copyfrom);
 247         else
 248                 retval = prefix_path(prefix, prefixlen, copyfrom);
 249         if (free_source)
 250                 free((char *)copyfrom);
 251         return retval;
 252 }
 253
 254 const char **get_pathspec(const char *prefix, const char **pathspec)
 255 {
 256         const char *entry = *pathspec;
 257         const char **src, **dst;
 258         int prefixlen;
 259
 260         if (!prefix && !entry)
 261                 return NULL;
 262
 263         if (!entry) {
 264                 static const char *spec[2];
 265                 spec[0] = prefix;
 266                 spec[1] = NULL;
 267                 return spec;
 268         }
 269
 270         /* Otherwise we have to re-write the entries.. */
 271         src = pathspec;
 272         dst = pathspec;
 273         prefixlen = prefix ? strlen(prefix) : 0;
 274         while (*src) {
 275                 *(dst++) = prefix_pathspec(prefix, prefixlen, *src);
 276                 src++;
 277         }
 278         *dst = NULL;
 279         if (!*pathspec)
 280                 return NULL;
 281         return pathspec;
 282 }
 283
 284 /*
 285  * Test if it looks like we're at a git directory.
 286  * We want to see:
 287  *
 288  *  - either an objects/ directory _or_ the proper
 289  *    GIT_OBJECT_DIRECTORY environment variable
 290  *  - a refs/ directory
 291  *  - either a HEAD symlink or a HEAD file that is formatted as
 292  *    a proper "ref:", or a regular file HEAD that has a properly
 293  *    formatted sha1 object name.
 294  */
 295 static int is_git_directory(const char *suspect)
 296 {
 297         char path[PATH_MAX];
 298         size_t len = strlen(suspect);
 299
 300         if (PATH_MAX <= len + strlen("/objects"))
 301                 die("Too long path: %.*s", 60, suspect);
 302         strcpy(path, suspect);
 303         if (getenv(DB_ENVIRONMENT)) {
 304                 if (access(getenv(DB_ENVIRONMENT), X_OK))
 305                         return 0;
 306         }
 307         else {
 308                 strcpy(path + len, "/objects");
 309                 if (access(path, X_OK))
 310                         return 0;
 311         }
 312
 313         strcpy(path + len, "/refs");
 314         if (access(path, X_OK))
 315                 return 0;
 316
 317         strcpy(path + len, "/HEAD");
 318         if (validate_headref(path))
 319                 return 0;
 320
 321         return 1;
 322 }
 323
 324 int is_inside_git_dir(void)
 325 {
 326         if (inside_git_dir < 0)
 327                 inside_git_dir = is_inside_dir(get_git_dir());
 328         return inside_git_dir;
 329 }
 330
 331 int is_inside_work_tree(void)
 332 {
 333         if (inside_work_tree < 0)
 334                 inside_work_tree = is_inside_dir(get_git_work_tree());
 335         return inside_work_tree;
 336 }
 337
 338 void setup_work_tree(void)
 339 {
 340         const char *work_tree, *git_dir;
 341         static int initialized = 0;
 342
 343         if (initialized)
 344                 return;
 345         work_tree = get_git_work_tree();
 346         git_dir = get_git_dir();
 347         if (!is_absolute_path(git_dir))
 348                 git_dir = real_path(get_git_dir());
 349         if (!work_tree || chdir(work_tree))
 350                 die("This operation must be run in a work tree");
 351
 352         /*
 353          * Make sure subsequent git processes find correct worktree
 354          * if $GIT_WORK_TREE is set relative
 355          */
 356         if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 357                 setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 358
 359         set_git_dir(relative_path(git_dir, work_tree));
 360         initialized = 1;
 361 }
 362
 363 static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 364 {
 365         char repo_config[PATH_MAX+1];
 366
 367         /*
 368          * git_config() can't be used here because it calls git_pathdup()
 369          * to get $GIT_CONFIG/config. That call will make setup_git_env()
 370          * set git_dir to ".git".
 371          *
 372          * We are in gitdir setup, no git dir has been found useable yet.
 373          * Use a gentler version of git_config() to check if this repo
 374          * is a good one.
 375          */
 376         snprintf(repo_config, PATH_MAX, "%s/config", gitdir);
 377         git_config_early(check_repository_format_version, NULL, repo_config);
 378         if (GIT_REPO_VERSION < repository_format_version) {
 379                 if (!nongit_ok)
 380                         die ("Expected git repo version <= %d, found %d",
 381                              GIT_REPO_VERSION, repository_format_version);
 382                 warning("Expected git repo version <= %d, found %d",
 383                         GIT_REPO_VERSION, repository_format_version);
 384                 warning("Please upgrade Git");
 385                 *nongit_ok = -1;
 386                 return -1;
 387         }
 388         return 0;
 389 }
 390
 391 /*
 392  * Try to read the location of the git directory from the .git file,
 393  * return path to git directory if found.
 394  */
 395 const char *read_gitfile_gently(const char *path)
 396 {
 397         char *buf;
 398         char *dir;
 399         const char *slash;
 400         struct stat st;
 401         int fd;
 402         size_t len;
 403
 404         if (stat(path, &st))
 405                 return NULL;
 406         if (!S_ISREG(st.st_mode))
 407                 return NULL;
 408         fd = open(path, O_RDONLY);
 409         if (fd < 0)
 410                 die_errno("Error opening '%s'", path);
 411         buf = xmalloc(st.st_size + 1);
 412         len = read_in_full(fd, buf, st.st_size);
 413         close(fd);
 414         if (len != st.st_size)
 415                 die("Error reading %s", path);
 416         buf[len] = '\0';
 417         if (prefixcmp(buf, "gitdir: "))
 418                 die("Invalid gitfile format: %s", path);
 419         while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 420                 len--;
 421         if (len < 9)
 422                 die("No path in gitfile: %s", path);
 423         buf[len] = '\0';
 424         dir = buf + 8;
 425
 426         if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
 427                 size_t pathlen = slash+1 - path;
 428                 size_t dirlen = pathlen + len - 8;
 429                 dir = xmalloc(dirlen + 1);
 430                 strncpy(dir, path, pathlen);
 431                 strncpy(dir + pathlen, buf + 8, len - 8);
 432                 dir[dirlen] = '\0';
 433                 free(buf);
 434                 buf = dir;
 435         }
 436
 437         if (!is_git_directory(dir))
 438                 die("Not a git repository: %s", dir);
 439         path = real_path(dir);
 440
 441         free(buf);
 442         return path;
 443 }
 444
 445 static const char *setup_explicit_git_dir(const char *gitdirenv,
 446                                           char *cwd, int len,
 447                                           int *nongit_ok)
 448 {
 449         const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 450         const char *worktree;
 451         char *gitfile;
 452         int offset;
 453
 454         if (PATH_MAX - 40 < strlen(gitdirenv))
 455                 die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 456
 457         gitfile = (char*)read_gitfile_gently(gitdirenv);
 458         if (gitfile) {
 459                 gitfile = xstrdup(gitfile);
 460                 gitdirenv = gitfile;
 461         }
 462
 463         if (!is_git_directory(gitdirenv)) {
 464                 if (nongit_ok) {
 465                         *nongit_ok = 1;
 466                         free(gitfile);
 467                         return NULL;
 468                 }
 469                 die("Not a git repository: '%s'", gitdirenv);
 470         }
 471
 472         if (check_repository_format_gently(gitdirenv, nongit_ok)) {
 473                 free(gitfile);
 474                 return NULL;
 475         }
 476
 477         /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
 478         if (work_tree_env)
 479                 set_git_work_tree(work_tree_env);
 480         else if (is_bare_repository_cfg > 0) {
 481                 if (git_work_tree_cfg) /* #22.2, #30 */
 482                         die("core.bare and core.worktree do not make sense");
 483
 484                 /* #18, #26 */
 485                 set_git_dir(gitdirenv);
 486                 free(gitfile);
 487                 return NULL;
 488         }
 489         else if (git_work_tree_cfg) { /* #6, #14 */
 490                 if (is_absolute_path(git_work_tree_cfg))
 491                         set_git_work_tree(git_work_tree_cfg);
 492                 else {
 493                         char core_worktree[PATH_MAX];
 494                         if (chdir(gitdirenv))
 495                                 die_errno("Could not chdir to '%s'", gitdirenv);
 496                         if (chdir(git_work_tree_cfg))
 497                                 die_errno("Could not chdir to '%s'", git_work_tree_cfg);
 498                         if (!getcwd(core_worktree, PATH_MAX))
 499                                 die_errno("Could not get directory '%s'", git_work_tree_cfg);
 500                         if (chdir(cwd))
 501                                 die_errno("Could not come back to cwd");
 502                         set_git_work_tree(core_worktree);
 503                 }
 504         }
 505         else /* #2, #10 */
 506                 set_git_work_tree(".");
 507
 508         /* set_git_work_tree() must have been called by now */
 509         worktree = get_git_work_tree();
 510
 511         /* both get_git_work_tree() and cwd are already normalized */
 512         if (!strcmp(cwd, worktree)) { /* cwd == worktree */
 513                 set_git_dir(gitdirenv);
 514                 free(gitfile);
 515                 return NULL;
 516         }
 517
 518         offset = dir_inside_of(cwd, worktree);
 519         if (offset >= 0) {      /* cwd inside worktree? */
 520                 set_git_dir(real_path(gitdirenv));
 521                 if (chdir(worktree))
 522                         die_errno("Could not chdir to '%s'", worktree);
 523                 cwd[len++] = '/';
 524                 cwd[len] = '\0';
 525                 free(gitfile);
 526                 return cwd + offset;
 527         }
 528
 529         /* cwd outside worktree */
 530         set_git_dir(gitdirenv);
 531         free(gitfile);
 532         return NULL;
 533 }
 534
 535 static const char *setup_discovered_git_dir(const char *gitdir,
 536                                             char *cwd, int offset, int len,
 537                                             int *nongit_ok)
 538 {
 539         if (check_repository_format_gently(gitdir, nongit_ok))
 540                 return NULL;
 541
 542         /* --work-tree is set without --git-dir; use discovered one */
 543         if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 544                 if (offset != len && !is_absolute_path(gitdir))
 545                         gitdir = xstrdup(real_path(gitdir));
 546                 if (chdir(cwd))
 547                         die_errno("Could not come back to cwd");
 548                 return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
 549         }
 550
 551         /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 552         if (is_bare_repository_cfg > 0) {
 553                 set_git_dir(offset == len ? gitdir : real_path(gitdir));
 554                 if (chdir(cwd))
 555                         die_errno("Could not come back to cwd");
 556                 return NULL;
 557         }
 558
 559         /* #0, #1, #5, #8, #9, #12, #13 */
 560         set_git_work_tree(".");
 561         if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
 562                 set_git_dir(gitdir);
 563         inside_git_dir = 0;
 564         inside_work_tree = 1;
 565         if (offset == len)
 566                 return NULL;
 567
 568         /* Make "offset" point to past the '/', and add a '/' at the end */
 569         offset++;
 570         cwd[len++] = '/';
 571         cwd[len] = 0;
 572         return cwd + offset;
 573 }
 574
 575 /* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
 576 static const char *setup_bare_git_dir(char *cwd, int offset, int len, int *nongit_ok)
 577 {
 578         int root_len;
 579
 580         if (check_repository_format_gently(".", nongit_ok))
 581                 return NULL;
 582
 583         /* --work-tree is set without --git-dir; use discovered one */
 584         if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 585                 const char *gitdir;
 586
 587                 gitdir = offset == len ? "." : xmemdupz(cwd, offset);
 588                 if (chdir(cwd))
 589                         die_errno("Could not come back to cwd");
 590                 return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
 591         }
 592
 593         inside_git_dir = 1;
 594         inside_work_tree = 0;
 595         if (offset != len) {
 596                 if (chdir(cwd))
 597                         die_errno("Cannot come back to cwd");
 598                 root_len = offset_1st_component(cwd);
 599                 cwd[offset > root_len ? offset : root_len] = '\0';
 600                 set_git_dir(cwd);
 601         }
 602         else
 603                 set_git_dir(".");
 604         return NULL;
 605 }
 606
 607 static const char *setup_nongit(const char *cwd, int *nongit_ok)
 608 {
 609         if (!nongit_ok)
 610                 die("Not a git repository (or any of the parent directories): %s", DEFAULT_GIT_DIR_ENVIRONMENT);
 611         if (chdir(cwd))
 612                 die_errno("Cannot come back to cwd");
 613         *nongit_ok = 1;
 614         return NULL;
 615 }
 616
 617 static dev_t get_device_or_die(const char *path, const char *prefix)
 618 {
 619         struct stat buf;
 620         if (stat(path, &buf))
 621                 die_errno("failed to stat '%s%s%s'",
 622                                 prefix ? prefix : "",
 623                                 prefix ? "/" : "", path);
 624         return buf.st_dev;
 625 }
 626
 627 /*
 628  * We cannot decide in this function whether we are in the work tree or
 629  * not, since the config can only be read _after_ this function was called.
 630  */
 631 static const char *setup_git_directory_gently_1(int *nongit_ok)
 632 {
 633         const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 634         static char cwd[PATH_MAX+1];
 635         const char *gitdirenv, *ret;
 636         char *gitfile;
 637         int len, offset, ceil_offset;
 638         dev_t current_device = 0;
 639         int one_filesystem = 1;
 640
 641         /*
 642          * Let's assume that we are in a git repository.
 643          * If it turns out later that we are somewhere else, the value will be
 644          * updated accordingly.
 645          */
 646         if (nongit_ok)
 647                 *nongit_ok = 0;
 648
 649         if (!getcwd(cwd, sizeof(cwd)-1))
 650                 die_errno("Unable to read current working directory");
 651         offset = len = strlen(cwd);
 652
 653         /*
 654          * If GIT_DIR is set explicitly, we're not going
 655          * to do any discovery, but we still do repository
 656          * validation.
 657          */
 658         gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 659         if (gitdirenv)
 660                 return setup_explicit_git_dir(gitdirenv, cwd, len, nongit_ok);
 661
 662         ceil_offset = longest_ancestor_length(cwd, env_ceiling_dirs);
 663         if (ceil_offset < 0 && has_dos_drive_prefix(cwd))
 664                 ceil_offset = 1;
 665
 666         /*
 667          * Test in the following order (relative to the cwd):
 668          * - .git (file containing "gitdir: <path>")
 669          * - .git/
 670          * - ./ (bare)
 671          * - ../.git
 672          * - ../.git/
 673          * - ../ (bare)
 674          * - ../../.git/
 675          *   etc.
 676          */
 677         one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
 678         if (one_filesystem)
 679                 current_device = get_device_or_die(".", NULL);
 680         for (;;) {
 681                 gitfile = (char*)read_gitfile_gently(DEFAULT_GIT_DIR_ENVIRONMENT);
 682                 if (gitfile)
 683                         gitdirenv = gitfile = xstrdup(gitfile);
 684                 else {
 685                         if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 686                                 gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
 687                 }
 688
 689                 if (gitdirenv) {
 690                         ret = setup_discovered_git_dir(gitdirenv,
 691                                                        cwd, offset, len,
 692                                                        nongit_ok);
 693                         free(gitfile);
 694                         return ret;
 695                 }
 696                 free(gitfile);
 697
 698                 if (is_git_directory("."))
 699                         return setup_bare_git_dir(cwd, offset, len, nongit_ok);
 700
 701                 while (--offset > ceil_offset && cwd[offset] != '/');
 702                 if (offset <= ceil_offset)
 703                         return setup_nongit(cwd, nongit_ok);
 704                 if (one_filesystem) {
 705                         dev_t parent_device = get_device_or_die("..", cwd);
 706                         if (parent_device != current_device) {
 707                                 if (nongit_ok) {
 708                                         if (chdir(cwd))
 709                                                 die_errno("Cannot come back to cwd");
 710                                         *nongit_ok = 1;
 711                                         return NULL;
 712                                 }
 713                                 cwd[offset] = '\0';
 714                                 die("Not a git repository (or any parent up to mount parent %s)\n"
 715                                 "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).", cwd);
 716                         }
 717                 }
 718                 if (chdir("..")) {
 719                         cwd[offset] = '\0';
 720                         die_errno("Cannot change to '%s/..'", cwd);
 721                 }
 722         }
 723 }
 724
 725 const char *setup_git_directory_gently(int *nongit_ok)
 726 {
 727         const char *prefix;
 728
 729         prefix = setup_git_directory_gently_1(nongit_ok);
 730         if (startup_info) {
 731                 startup_info->have_repository = !nongit_ok || !*nongit_ok;
 732                 startup_info->prefix = prefix;
 733         }
 734         return prefix;
 735 }
 736
 737 int git_config_perm(const char *var, const char *value)
 738 {
 739         int i;
 740         char *endptr;
 741
 742         if (value == NULL)
 743                 return PERM_GROUP;
 744
 745         if (!strcmp(value, "umask"))
 746                 return PERM_UMASK;
 747         if (!strcmp(value, "group"))
 748                 return PERM_GROUP;
 749         if (!strcmp(value, "all") ||
 750             !strcmp(value, "world") ||
 751             !strcmp(value, "everybody"))
 752                 return PERM_EVERYBODY;
 753
 754         /* Parse octal numbers */
 755         i = strtol(value, &endptr, 8);
 756
 757         /* If not an octal number, maybe true/false? */
 758         if (*endptr != 0)
 759                 return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
 760
 761         /*
 762          * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
 763          * a chmod value to restrict to.
 764          */
 765         switch (i) {
 766         case PERM_UMASK:               /* 0 */
 767                 return PERM_UMASK;
 768         case OLD_PERM_GROUP:           /* 1 */
 769                 return PERM_GROUP;
 770         case OLD_PERM_EVERYBODY:       /* 2 */
 771                 return PERM_EVERYBODY;
 772         }
 773
 774         /* A filemode value was given: 0xxx */
 775
 776         if ((i & 0600) != 0600)
 777                 die("Problem with core.sharedRepository filemode value "
 778                     "(0%.3o).\nThe owner of files must always have "
 779                     "read and write permissions.", i);
 780
 781         /*
 782          * Mask filemode value. Others can not get write permission.
 783          * x flags for directories are handled separately.
 784          */
 785         return -(i & 0666);
 786 }
 787
 788 int check_repository_format_version(const char *var, const char *value, void *cb)
 789 {
 790         if (strcmp(var, "core.repositoryformatversion") == 0)
 791                 repository_format_version = git_config_int(var, value);
 792         else if (strcmp(var, "core.sharedrepository") == 0)
 793                 shared_repository = git_config_perm(var, value);
 794         else if (strcmp(var, "core.bare") == 0) {
 795                 is_bare_repository_cfg = git_config_bool(var, value);
 796                 if (is_bare_repository_cfg == 1)
 797                         inside_work_tree = -1;
 798         } else if (strcmp(var, "core.worktree") == 0) {
 799                 if (!value)
 800                         return config_error_nonbool(var);
 801                 free(git_work_tree_cfg);
 802                 git_work_tree_cfg = xstrdup(value);
 803                 inside_work_tree = -1;
 804         }
 805         return 0;
 806 }
 807
 808 int check_repository_format(void)
 809 {
 810         return check_repository_format_gently(get_git_dir(), NULL);
 811 }
 812
 813 /*
 814  * Returns the "prefix", a path to the current working directory
 815  * relative to the work tree root, or NULL, if the current working
 816  * directory is not a strict subdirectory of the work tree root. The
 817  * prefix always ends with a '/' character.
 818  */
 819 const char *setup_git_directory(void)
 820 {
 821         return setup_git_directory_gently(NULL);
 822 }