setup.con commit documentation fix: git difftool uses diff tools, not merge tools. (1e501a7)
   1#include "cache.h"
   2#include "dir.h"
   3
   4static int inside_git_dir = -1;
   5static int inside_work_tree = -1;
   6
   7char *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
  43int check_filename(const char *prefix, const char *arg)
  44{
  45        const char *name;
  46        struct stat st;
  47
  48        name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
  49        if (!lstat(name, &st))
  50                return 1; /* file exists */
  51        if (errno == ENOENT || errno == ENOTDIR)
  52                return 0; /* file does not exist */
  53        die_errno("failed to stat '%s'", arg);
  54}
  55
  56static void NORETURN die_verify_filename(const char *prefix, const char *arg)
  57{
  58        unsigned char sha1[20];
  59        unsigned mode;
  60
  61        /*
  62         * Saying "'(icase)foo' does not exist in the index" when the
  63         * user gave us ":(icase)foo" is just stupid.  A magic pathspec
  64         * begins with a colon and is followed by a non-alnum; do not
  65         * let get_sha1_with_mode_1(only_to_die=1) to even trigger.
  66         */
  67        if (!(arg[0] == ':' && !isalnum(arg[1])))
  68                /* try a detailed diagnostic ... */
  69                get_sha1_with_mode_1(arg, sha1, &mode, 1, prefix);
  70
  71        /* ... or fall back the most general message. */
  72        die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
  73            "Use '--' to separate paths from revisions", arg);
  74
  75}
  76
  77/*
  78 * Verify a filename that we got as an argument for a pathspec
  79 * entry. Note that a filename that begins with "-" never verifies
  80 * as true, because even if such a filename were to exist, we want
  81 * it to be preceded by the "--" marker (or we want the user to
  82 * use a format like "./-filename")
  83 */
  84void verify_filename(const char *prefix, const char *arg)
  85{
  86        if (*arg == '-')
  87                die("bad flag '%s' used after filename", arg);
  88        if (check_filename(prefix, arg))
  89                return;
  90        die_verify_filename(prefix, arg);
  91}
  92
  93/*
  94 * Opposite of the above: the command line did not have -- marker
  95 * and we parsed the arg as a refname.  It should not be interpretable
  96 * as a filename.
  97 */
  98void verify_non_filename(const char *prefix, const char *arg)
  99{
 100        if (!is_inside_work_tree() || is_inside_git_dir())
 101                return;
 102        if (*arg == '-')
 103                return; /* flag */
 104        if (!check_filename(prefix, arg))
 105                return;
 106        die("ambiguous argument '%s': both revision and filename\n"
 107            "Use '--' to separate filenames from revisions", arg);
 108}
 109
 110/*
 111 * Magic pathspec
 112 *
 113 * NEEDSWORK: These need to be moved to dir.h or even to a new
 114 * pathspec.h when we restructure get_pathspec() users to use the
 115 * "struct pathspec" interface.
 116 *
 117 * Possible future magic semantics include stuff like:
 118 *
 119 *      { PATHSPEC_NOGLOB, '!', "noglob" },
 120 *      { PATHSPEC_ICASE, '\0', "icase" },
 121 *      { PATHSPEC_RECURSIVE, '*', "recursive" },
 122 *      { PATHSPEC_REGEXP, '\0', "regexp" },
 123 *
 124 */
 125#define PATHSPEC_FROMTOP    (1<<0)
 126
 127static struct pathspec_magic {
 128        unsigned bit;
 129        char mnemonic; /* this cannot be ':'! */
 130        const char *name;
 131} pathspec_magic[] = {
 132        { PATHSPEC_FROMTOP, '/', "top" },
 133};
 134
 135/*
 136 * Take an element of a pathspec and check for magic signatures.
 137 * Append the result to the prefix.
 138 *
 139 * For now, we only parse the syntax and throw out anything other than
 140 * "top" magic.
 141 *
 142 * NEEDSWORK: This needs to be rewritten when we start migrating
 143 * get_pathspec() users to use the "struct pathspec" interface.  For
 144 * example, a pathspec element may be marked as case-insensitive, but
 145 * the prefix part must always match literally, and a single stupid
 146 * string cannot express such a case.
 147 */
 148static const char *prefix_pathspec(const char *prefix, int prefixlen, const char *elt)
 149{
 150        unsigned magic = 0;
 151        const char *copyfrom = elt;
 152        int i;
 153
 154        if (elt[0] != ':') {
 155                ; /* nothing to do */
 156        } else if (elt[1] == '(') {
 157                /* longhand */
 158                const char *nextat;
 159                for (copyfrom = elt + 2;
 160                     *copyfrom && *copyfrom != ')';
 161                     copyfrom = nextat) {
 162                        size_t len = strcspn(copyfrom, ",)");
 163                        if (copyfrom[len] == ')')
 164                                nextat = copyfrom + len;
 165                        else
 166                                nextat = copyfrom + len + 1;
 167                        if (!len)
 168                                continue;
 169                        for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
 170                                if (strlen(pathspec_magic[i].name) == len &&
 171                                    !strncmp(pathspec_magic[i].name, copyfrom, len)) {
 172                                        magic |= pathspec_magic[i].bit;
 173                                        break;
 174                                }
 175                        if (ARRAY_SIZE(pathspec_magic) <= i)
 176                                die("Invalid pathspec magic '%.*s' in '%s'",
 177                                    (int) len, copyfrom, elt);
 178                }
 179                if (*copyfrom == ')')
 180                        copyfrom++;
 181        } else {
 182                /* shorthand */
 183                for (copyfrom = elt + 1;
 184                     *copyfrom && *copyfrom != ':';
 185                     copyfrom++) {
 186                        char ch = *copyfrom;
 187
 188                        if (!is_pathspec_magic(ch))
 189                                break;
 190                        for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
 191                                if (pathspec_magic[i].mnemonic == ch) {
 192                                        magic |= pathspec_magic[i].bit;
 193                                        break;
 194                                }
 195                        if (ARRAY_SIZE(pathspec_magic) <= i)
 196                                die("Unimplemented pathspec magic '%c' in '%s'",
 197                                    ch, elt);
 198                }
 199                if (*copyfrom == ':')
 200                        copyfrom++;
 201        }
 202
 203        if (magic & PATHSPEC_FROMTOP)
 204                return xstrdup(copyfrom);
 205        else
 206                return prefix_path(prefix, prefixlen, copyfrom);
 207}
 208
 209const char **get_pathspec(const char *prefix, const char **pathspec)
 210{
 211        const char *entry = *pathspec;
 212        const char **src, **dst;
 213        int prefixlen;
 214
 215        if (!prefix && !entry)
 216                return NULL;
 217
 218        if (!entry) {
 219                static const char *spec[2];
 220                spec[0] = prefix;
 221                spec[1] = NULL;
 222                return spec;
 223        }
 224
 225        /* Otherwise we have to re-write the entries.. */
 226        src = pathspec;
 227        dst = pathspec;
 228        prefixlen = prefix ? strlen(prefix) : 0;
 229        while (*src) {
 230                *(dst++) = prefix_pathspec(prefix, prefixlen, *src);
 231                src++;
 232        }
 233        *dst = NULL;
 234        if (!*pathspec)
 235                return NULL;
 236        return pathspec;
 237}
 238
 239const char *pathspec_prefix(const char *prefix, const char **pathspec)
 240{
 241        const char **p, *n, *prev;
 242        unsigned long max;
 243
 244        if (!pathspec)
 245                return prefix ? xmemdupz(prefix, strlen(prefix)) : NULL;
 246
 247        prev = NULL;
 248        max = PATH_MAX;
 249        for (p = pathspec; (n = *p) != NULL; p++) {
 250                int i, len = 0;
 251                for (i = 0; i < max; i++) {
 252                        char c = n[i];
 253                        if (prev && prev[i] != c)
 254                                break;
 255                        if (!c || c == '*' || c == '?')
 256                                break;
 257                        if (c == '/')
 258                                len = i+1;
 259                }
 260                prev = n;
 261                if (len < max) {
 262                        max = len;
 263                        if (!max)
 264                                break;
 265                }
 266        }
 267
 268        return max ? xmemdupz(prev, max) : NULL;
 269}
 270
 271/*
 272 * Test if it looks like we're at a git directory.
 273 * We want to see:
 274 *
 275 *  - either an objects/ directory _or_ the proper
 276 *    GIT_OBJECT_DIRECTORY environment variable
 277 *  - a refs/ directory
 278 *  - either a HEAD symlink or a HEAD file that is formatted as
 279 *    a proper "ref:", or a regular file HEAD that has a properly
 280 *    formatted sha1 object name.
 281 */
 282static int is_git_directory(const char *suspect)
 283{
 284        char path[PATH_MAX];
 285        size_t len = strlen(suspect);
 286
 287        if (PATH_MAX <= len + strlen("/objects"))
 288                die("Too long path: %.*s", 60, suspect);
 289        strcpy(path, suspect);
 290        if (getenv(DB_ENVIRONMENT)) {
 291                if (access(getenv(DB_ENVIRONMENT), X_OK))
 292                        return 0;
 293        }
 294        else {
 295                strcpy(path + len, "/objects");
 296                if (access(path, X_OK))
 297                        return 0;
 298        }
 299
 300        strcpy(path + len, "/refs");
 301        if (access(path, X_OK))
 302                return 0;
 303
 304        strcpy(path + len, "/HEAD");
 305        if (validate_headref(path))
 306                return 0;
 307
 308        return 1;
 309}
 310
 311int is_inside_git_dir(void)
 312{
 313        if (inside_git_dir < 0)
 314                inside_git_dir = is_inside_dir(get_git_dir());
 315        return inside_git_dir;
 316}
 317
 318int is_inside_work_tree(void)
 319{
 320        if (inside_work_tree < 0)
 321                inside_work_tree = is_inside_dir(get_git_work_tree());
 322        return inside_work_tree;
 323}
 324
 325void setup_work_tree(void)
 326{
 327        const char *work_tree, *git_dir;
 328        static int initialized = 0;
 329
 330        if (initialized)
 331                return;
 332        work_tree = get_git_work_tree();
 333        git_dir = get_git_dir();
 334        if (!is_absolute_path(git_dir))
 335                git_dir = real_path(get_git_dir());
 336        if (!work_tree || chdir(work_tree))
 337                die("This operation must be run in a work tree");
 338
 339        /*
 340         * Make sure subsequent git processes find correct worktree
 341         * if $GIT_WORK_TREE is set relative
 342         */
 343        if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 344                setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 345
 346        set_git_dir(relative_path(git_dir, work_tree));
 347        initialized = 1;
 348}
 349
 350static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 351{
 352        char repo_config[PATH_MAX+1];
 353
 354        /*
 355         * git_config() can't be used here because it calls git_pathdup()
 356         * to get $GIT_CONFIG/config. That call will make setup_git_env()
 357         * set git_dir to ".git".
 358         *
 359         * We are in gitdir setup, no git dir has been found useable yet.
 360         * Use a gentler version of git_config() to check if this repo
 361         * is a good one.
 362         */
 363        snprintf(repo_config, PATH_MAX, "%s/config", gitdir);
 364        git_config_early(check_repository_format_version, NULL, repo_config);
 365        if (GIT_REPO_VERSION < repository_format_version) {
 366                if (!nongit_ok)
 367                        die ("Expected git repo version <= %d, found %d",
 368                             GIT_REPO_VERSION, repository_format_version);
 369                warning("Expected git repo version <= %d, found %d",
 370                        GIT_REPO_VERSION, repository_format_version);
 371                warning("Please upgrade Git");
 372                *nongit_ok = -1;
 373                return -1;
 374        }
 375        return 0;
 376}
 377
 378/*
 379 * Try to read the location of the git directory from the .git file,
 380 * return path to git directory if found.
 381 */
 382const char *read_gitfile(const char *path)
 383{
 384        char *buf;
 385        char *dir;
 386        const char *slash;
 387        struct stat st;
 388        int fd;
 389        ssize_t len;
 390
 391        if (stat(path, &st))
 392                return NULL;
 393        if (!S_ISREG(st.st_mode))
 394                return NULL;
 395        fd = open(path, O_RDONLY);
 396        if (fd < 0)
 397                die_errno("Error opening '%s'", path);
 398        buf = xmalloc(st.st_size + 1);
 399        len = read_in_full(fd, buf, st.st_size);
 400        close(fd);
 401        if (len != st.st_size)
 402                die("Error reading %s", path);
 403        buf[len] = '\0';
 404        if (prefixcmp(buf, "gitdir: "))
 405                die("Invalid gitfile format: %s", path);
 406        while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 407                len--;
 408        if (len < 9)
 409                die("No path in gitfile: %s", path);
 410        buf[len] = '\0';
 411        dir = buf + 8;
 412
 413        if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
 414                size_t pathlen = slash+1 - path;
 415                size_t dirlen = pathlen + len - 8;
 416                dir = xmalloc(dirlen + 1);
 417                strncpy(dir, path, pathlen);
 418                strncpy(dir + pathlen, buf + 8, len - 8);
 419                dir[dirlen] = '\0';
 420                free(buf);
 421                buf = dir;
 422        }
 423
 424        if (!is_git_directory(dir))
 425                die("Not a git repository: %s", dir);
 426        path = real_path(dir);
 427
 428        free(buf);
 429        return path;
 430}
 431
 432static const char *setup_explicit_git_dir(const char *gitdirenv,
 433                                          char *cwd, int len,
 434                                          int *nongit_ok)
 435{
 436        const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 437        const char *worktree;
 438        char *gitfile;
 439        int offset;
 440
 441        if (PATH_MAX - 40 < strlen(gitdirenv))
 442                die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 443
 444        gitfile = (char*)read_gitfile(gitdirenv);
 445        if (gitfile) {
 446                gitfile = xstrdup(gitfile);
 447                gitdirenv = gitfile;
 448        }
 449
 450        if (!is_git_directory(gitdirenv)) {
 451                if (nongit_ok) {
 452                        *nongit_ok = 1;
 453                        free(gitfile);
 454                        return NULL;
 455                }
 456                die("Not a git repository: '%s'", gitdirenv);
 457        }
 458
 459        if (check_repository_format_gently(gitdirenv, nongit_ok)) {
 460                free(gitfile);
 461                return NULL;
 462        }
 463
 464        /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
 465        if (work_tree_env)
 466                set_git_work_tree(work_tree_env);
 467        else if (is_bare_repository_cfg > 0) {
 468                if (git_work_tree_cfg) /* #22.2, #30 */
 469                        die("core.bare and core.worktree do not make sense");
 470
 471                /* #18, #26 */
 472                set_git_dir(gitdirenv);
 473                free(gitfile);
 474                return NULL;
 475        }
 476        else if (git_work_tree_cfg) { /* #6, #14 */
 477                if (is_absolute_path(git_work_tree_cfg))
 478                        set_git_work_tree(git_work_tree_cfg);
 479                else {
 480                        char core_worktree[PATH_MAX];
 481                        if (chdir(gitdirenv))
 482                                die_errno("Could not chdir to '%s'", gitdirenv);
 483                        if (chdir(git_work_tree_cfg))
 484                                die_errno("Could not chdir to '%s'", git_work_tree_cfg);
 485                        if (!getcwd(core_worktree, PATH_MAX))
 486                                die_errno("Could not get directory '%s'", git_work_tree_cfg);
 487                        if (chdir(cwd))
 488                                die_errno("Could not come back to cwd");
 489                        set_git_work_tree(core_worktree);
 490                }
 491        }
 492        else /* #2, #10 */
 493                set_git_work_tree(".");
 494
 495        /* set_git_work_tree() must have been called by now */
 496        worktree = get_git_work_tree();
 497
 498        /* both get_git_work_tree() and cwd are already normalized */
 499        if (!strcmp(cwd, worktree)) { /* cwd == worktree */
 500                set_git_dir(gitdirenv);
 501                free(gitfile);
 502                return NULL;
 503        }
 504
 505        offset = dir_inside_of(cwd, worktree);
 506        if (offset >= 0) {      /* cwd inside worktree? */
 507                set_git_dir(real_path(gitdirenv));
 508                if (chdir(worktree))
 509                        die_errno("Could not chdir to '%s'", worktree);
 510                cwd[len++] = '/';
 511                cwd[len] = '\0';
 512                free(gitfile);
 513                return cwd + offset;
 514        }
 515
 516        /* cwd outside worktree */
 517        set_git_dir(gitdirenv);
 518        free(gitfile);
 519        return NULL;
 520}
 521
 522static const char *setup_discovered_git_dir(const char *gitdir,
 523                                            char *cwd, int offset, int len,
 524                                            int *nongit_ok)
 525{
 526        if (check_repository_format_gently(gitdir, nongit_ok))
 527                return NULL;
 528
 529        /* --work-tree is set without --git-dir; use discovered one */
 530        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 531                if (offset != len && !is_absolute_path(gitdir))
 532                        gitdir = xstrdup(real_path(gitdir));
 533                if (chdir(cwd))
 534                        die_errno("Could not come back to cwd");
 535                return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
 536        }
 537
 538        /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 539        if (is_bare_repository_cfg > 0) {
 540                set_git_dir(offset == len ? gitdir : real_path(gitdir));
 541                if (chdir(cwd))
 542                        die_errno("Could not come back to cwd");
 543                return NULL;
 544        }
 545
 546        /* #0, #1, #5, #8, #9, #12, #13 */
 547        set_git_work_tree(".");
 548        if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
 549                set_git_dir(gitdir);
 550        inside_git_dir = 0;
 551        inside_work_tree = 1;
 552        if (offset == len)
 553                return NULL;
 554
 555        /* Make "offset" point to past the '/', and add a '/' at the end */
 556        offset++;
 557        cwd[len++] = '/';
 558        cwd[len] = 0;
 559        return cwd + offset;
 560}
 561
 562/* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
 563static const char *setup_bare_git_dir(char *cwd, int offset, int len, int *nongit_ok)
 564{
 565        int root_len;
 566
 567        if (check_repository_format_gently(".", nongit_ok))
 568                return NULL;
 569
 570        /* --work-tree is set without --git-dir; use discovered one */
 571        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 572                const char *gitdir;
 573
 574                gitdir = offset == len ? "." : xmemdupz(cwd, offset);
 575                if (chdir(cwd))
 576                        die_errno("Could not come back to cwd");
 577                return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
 578        }
 579
 580        inside_git_dir = 1;
 581        inside_work_tree = 0;
 582        if (offset != len) {
 583                if (chdir(cwd))
 584                        die_errno("Cannot come back to cwd");
 585                root_len = offset_1st_component(cwd);
 586                cwd[offset > root_len ? offset : root_len] = '\0';
 587                set_git_dir(cwd);
 588        }
 589        else
 590                set_git_dir(".");
 591        return NULL;
 592}
 593
 594static const char *setup_nongit(const char *cwd, int *nongit_ok)
 595{
 596        if (!nongit_ok)
 597                die("Not a git repository (or any of the parent directories): %s", DEFAULT_GIT_DIR_ENVIRONMENT);
 598        if (chdir(cwd))
 599                die_errno("Cannot come back to cwd");
 600        *nongit_ok = 1;
 601        return NULL;
 602}
 603
 604static dev_t get_device_or_die(const char *path, const char *prefix)
 605{
 606        struct stat buf;
 607        if (stat(path, &buf))
 608                die_errno("failed to stat '%s%s%s'",
 609                                prefix ? prefix : "",
 610                                prefix ? "/" : "", path);
 611        return buf.st_dev;
 612}
 613
 614/*
 615 * We cannot decide in this function whether we are in the work tree or
 616 * not, since the config can only be read _after_ this function was called.
 617 */
 618static const char *setup_git_directory_gently_1(int *nongit_ok)
 619{
 620        const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 621        static char cwd[PATH_MAX+1];
 622        const char *gitdirenv, *ret;
 623        char *gitfile;
 624        int len, offset, ceil_offset;
 625        dev_t current_device = 0;
 626        int one_filesystem = 1;
 627
 628        /*
 629         * Let's assume that we are in a git repository.
 630         * If it turns out later that we are somewhere else, the value will be
 631         * updated accordingly.
 632         */
 633        if (nongit_ok)
 634                *nongit_ok = 0;
 635
 636        if (!getcwd(cwd, sizeof(cwd)-1))
 637                die_errno("Unable to read current working directory");
 638        offset = len = strlen(cwd);
 639
 640        /*
 641         * If GIT_DIR is set explicitly, we're not going
 642         * to do any discovery, but we still do repository
 643         * validation.
 644         */
 645        gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 646        if (gitdirenv)
 647                return setup_explicit_git_dir(gitdirenv, cwd, len, nongit_ok);
 648
 649        ceil_offset = longest_ancestor_length(cwd, env_ceiling_dirs);
 650        if (ceil_offset < 0 && has_dos_drive_prefix(cwd))
 651                ceil_offset = 1;
 652
 653        /*
 654         * Test in the following order (relative to the cwd):
 655         * - .git (file containing "gitdir: <path>")
 656         * - .git/
 657         * - ./ (bare)
 658         * - ../.git
 659         * - ../.git/
 660         * - ../ (bare)
 661         * - ../../.git/
 662         *   etc.
 663         */
 664        one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
 665        if (one_filesystem)
 666                current_device = get_device_or_die(".", NULL);
 667        for (;;) {
 668                gitfile = (char*)read_gitfile(DEFAULT_GIT_DIR_ENVIRONMENT);
 669                if (gitfile)
 670                        gitdirenv = gitfile = xstrdup(gitfile);
 671                else {
 672                        if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 673                                gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
 674                }
 675
 676                if (gitdirenv) {
 677                        ret = setup_discovered_git_dir(gitdirenv,
 678                                                       cwd, offset, len,
 679                                                       nongit_ok);
 680                        free(gitfile);
 681                        return ret;
 682                }
 683                free(gitfile);
 684
 685                if (is_git_directory("."))
 686                        return setup_bare_git_dir(cwd, offset, len, nongit_ok);
 687
 688                while (--offset > ceil_offset && cwd[offset] != '/');
 689                if (offset <= ceil_offset)
 690                        return setup_nongit(cwd, nongit_ok);
 691                if (one_filesystem) {
 692                        dev_t parent_device = get_device_or_die("..", cwd);
 693                        if (parent_device != current_device) {
 694                                if (nongit_ok) {
 695                                        if (chdir(cwd))
 696                                                die_errno("Cannot come back to cwd");
 697                                        *nongit_ok = 1;
 698                                        return NULL;
 699                                }
 700                                cwd[offset] = '\0';
 701                                die("Not a git repository (or any parent up to mount parent %s)\n"
 702                                "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).", cwd);
 703                        }
 704                }
 705                if (chdir("..")) {
 706                        cwd[offset] = '\0';
 707                        die_errno("Cannot change to '%s/..'", cwd);
 708                }
 709        }
 710}
 711
 712const char *setup_git_directory_gently(int *nongit_ok)
 713{
 714        const char *prefix;
 715
 716        prefix = setup_git_directory_gently_1(nongit_ok);
 717        if (prefix)
 718                setenv("GIT_PREFIX", prefix, 1);
 719        else
 720                setenv("GIT_PREFIX", "", 1);
 721
 722        if (startup_info) {
 723                startup_info->have_repository = !nongit_ok || !*nongit_ok;
 724                startup_info->prefix = prefix;
 725        }
 726        return prefix;
 727}
 728
 729int git_config_perm(const char *var, const char *value)
 730{
 731        int i;
 732        char *endptr;
 733
 734        if (value == NULL)
 735                return PERM_GROUP;
 736
 737        if (!strcmp(value, "umask"))
 738                return PERM_UMASK;
 739        if (!strcmp(value, "group"))
 740                return PERM_GROUP;
 741        if (!strcmp(value, "all") ||
 742            !strcmp(value, "world") ||
 743            !strcmp(value, "everybody"))
 744                return PERM_EVERYBODY;
 745
 746        /* Parse octal numbers */
 747        i = strtol(value, &endptr, 8);
 748
 749        /* If not an octal number, maybe true/false? */
 750        if (*endptr != 0)
 751                return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
 752
 753        /*
 754         * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
 755         * a chmod value to restrict to.
 756         */
 757        switch (i) {
 758        case PERM_UMASK:               /* 0 */
 759                return PERM_UMASK;
 760        case OLD_PERM_GROUP:           /* 1 */
 761                return PERM_GROUP;
 762        case OLD_PERM_EVERYBODY:       /* 2 */
 763                return PERM_EVERYBODY;
 764        }
 765
 766        /* A filemode value was given: 0xxx */
 767
 768        if ((i & 0600) != 0600)
 769                die("Problem with core.sharedRepository filemode value "
 770                    "(0%.3o).\nThe owner of files must always have "
 771                    "read and write permissions.", i);
 772
 773        /*
 774         * Mask filemode value. Others can not get write permission.
 775         * x flags for directories are handled separately.
 776         */
 777        return -(i & 0666);
 778}
 779
 780int check_repository_format_version(const char *var, const char *value, void *cb)
 781{
 782        if (strcmp(var, "core.repositoryformatversion") == 0)
 783                repository_format_version = git_config_int(var, value);
 784        else if (strcmp(var, "core.sharedrepository") == 0)
 785                shared_repository = git_config_perm(var, value);
 786        else if (strcmp(var, "core.bare") == 0) {
 787                is_bare_repository_cfg = git_config_bool(var, value);
 788                if (is_bare_repository_cfg == 1)
 789                        inside_work_tree = -1;
 790        } else if (strcmp(var, "core.worktree") == 0) {
 791                if (!value)
 792                        return config_error_nonbool(var);
 793                free(git_work_tree_cfg);
 794                git_work_tree_cfg = xstrdup(value);
 795                inside_work_tree = -1;
 796        }
 797        return 0;
 798}
 799
 800int check_repository_format(void)
 801{
 802        return check_repository_format_gently(get_git_dir(), NULL);
 803}
 804
 805/*
 806 * Returns the "prefix", a path to the current working directory
 807 * relative to the work tree root, or NULL, if the current working
 808 * directory is not a strict subdirectory of the work tree root. The
 809 * prefix always ends with a '/' character.
 810 */
 811const char *setup_git_directory(void)
 812{
 813        return setup_git_directory_gently(NULL);
 814}