setup.c

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