setup.con commit Merge branch 'jn/warn-on-inaccessible-loosen' (4f43e97)
   1#include "cache.h"
   2#include "dir.h"
   3#include "string-list.h"
   4
   5static int inside_git_dir = -1;
   6static int inside_work_tree = -1;
   7
   8static char *prefix_path_gently(const char *prefix, int len, const char *path)
   9{
  10        const char *orig = path;
  11        char *sanitized;
  12        if (is_absolute_path(orig)) {
  13                const char *temp = real_path(path);
  14                sanitized = xmalloc(len + strlen(temp) + 1);
  15                strcpy(sanitized, temp);
  16        } else {
  17                sanitized = xmalloc(len + strlen(path) + 1);
  18                if (len)
  19                        memcpy(sanitized, prefix, len);
  20                strcpy(sanitized + len, path);
  21        }
  22        if (normalize_path_copy(sanitized, sanitized))
  23                goto error_out;
  24        if (is_absolute_path(orig)) {
  25                size_t root_len, len, total;
  26                const char *work_tree = get_git_work_tree();
  27                if (!work_tree)
  28                        goto error_out;
  29                len = strlen(work_tree);
  30                root_len = offset_1st_component(work_tree);
  31                total = strlen(sanitized) + 1;
  32                if (strncmp(sanitized, work_tree, len) ||
  33                    (len > root_len && sanitized[len] != '\0' && sanitized[len] != '/')) {
  34                error_out:
  35                        free(sanitized);
  36                        return NULL;
  37                }
  38                if (sanitized[len] == '/')
  39                        len++;
  40                memmove(sanitized, sanitized + len, total - len);
  41        }
  42        return sanitized;
  43}
  44
  45char *prefix_path(const char *prefix, int len, const char *path)
  46{
  47        char *r = prefix_path_gently(prefix, len, path);
  48        if (!r)
  49                die("'%s' is outside repository", path);
  50        return r;
  51}
  52
  53int path_inside_repo(const char *prefix, const char *path)
  54{
  55        int len = prefix ? strlen(prefix) : 0;
  56        char *r = prefix_path_gently(prefix, len, path);
  57        if (r) {
  58                free(r);
  59                return 1;
  60        }
  61        return 0;
  62}
  63
  64int check_filename(const char *prefix, const char *arg)
  65{
  66        const char *name;
  67        struct stat st;
  68
  69        name = prefix ? prefix_filename(prefix, strlen(prefix), arg) : arg;
  70        if (!lstat(name, &st))
  71                return 1; /* file exists */
  72        if (errno == ENOENT || errno == ENOTDIR)
  73                return 0; /* file does not exist */
  74        die_errno("failed to stat '%s'", arg);
  75}
  76
  77static void NORETURN die_verify_filename(const char *prefix,
  78                                         const char *arg,
  79                                         int diagnose_misspelt_rev)
  80{
  81        if (!diagnose_misspelt_rev)
  82                die("%s: no such path in the working tree.\n"
  83                    "Use 'git <command> -- <path>...' to specify paths that do not exist locally.",
  84                    arg);
  85        /*
  86         * Saying "'(icase)foo' does not exist in the index" when the
  87         * user gave us ":(icase)foo" is just stupid.  A magic pathspec
  88         * begins with a colon and is followed by a non-alnum; do not
  89         * let maybe_die_on_misspelt_object_name() even trigger.
  90         */
  91        if (!(arg[0] == ':' && !isalnum(arg[1])))
  92                maybe_die_on_misspelt_object_name(arg, prefix);
  93
  94        /* ... or fall back the most general message. */
  95        die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
  96            "Use '--' to separate paths from revisions, like this:\n"
  97            "'git <command> [<revision>...] -- [<file>...]'", arg);
  98
  99}
 100
 101/*
 102 * Verify a filename that we got as an argument for a pathspec
 103 * entry. Note that a filename that begins with "-" never verifies
 104 * as true, because even if such a filename were to exist, we want
 105 * it to be preceded by the "--" marker (or we want the user to
 106 * use a format like "./-filename")
 107 *
 108 * The "diagnose_misspelt_rev" is used to provide a user-friendly
 109 * diagnosis when dying upon finding that "name" is not a pathname.
 110 * If set to 1, the diagnosis will try to diagnose "name" as an
 111 * invalid object name (e.g. HEAD:foo). If set to 0, the diagnosis
 112 * will only complain about an inexisting file.
 113 *
 114 * This function is typically called to check that a "file or rev"
 115 * argument is unambiguous. In this case, the caller will want
 116 * diagnose_misspelt_rev == 1 when verifying the first non-rev
 117 * argument (which could have been a revision), and
 118 * diagnose_misspelt_rev == 0 for the next ones (because we already
 119 * saw a filename, there's not ambiguity anymore).
 120 */
 121void verify_filename(const char *prefix,
 122                     const char *arg,
 123                     int diagnose_misspelt_rev)
 124{
 125        if (*arg == '-')
 126                die("bad flag '%s' used after filename", arg);
 127        if (check_filename(prefix, arg))
 128                return;
 129        die_verify_filename(prefix, arg, diagnose_misspelt_rev);
 130}
 131
 132/*
 133 * Opposite of the above: the command line did not have -- marker
 134 * and we parsed the arg as a refname.  It should not be interpretable
 135 * as a filename.
 136 */
 137void verify_non_filename(const char *prefix, const char *arg)
 138{
 139        if (!is_inside_work_tree() || is_inside_git_dir())
 140                return;
 141        if (*arg == '-')
 142                return; /* flag */
 143        if (!check_filename(prefix, arg))
 144                return;
 145        die("ambiguous argument '%s': both revision and filename\n"
 146            "Use '--' to separate paths from revisions, like this:\n"
 147            "'git <command> [<revision>...] -- [<file>...]'", arg);
 148}
 149
 150/*
 151 * Magic pathspec
 152 *
 153 * NEEDSWORK: These need to be moved to dir.h or even to a new
 154 * pathspec.h when we restructure get_pathspec() users to use the
 155 * "struct pathspec" interface.
 156 *
 157 * Possible future magic semantics include stuff like:
 158 *
 159 *      { PATHSPEC_NOGLOB, '!', "noglob" },
 160 *      { PATHSPEC_ICASE, '\0', "icase" },
 161 *      { PATHSPEC_RECURSIVE, '*', "recursive" },
 162 *      { PATHSPEC_REGEXP, '\0', "regexp" },
 163 *
 164 */
 165#define PATHSPEC_FROMTOP    (1<<0)
 166
 167static struct pathspec_magic {
 168        unsigned bit;
 169        char mnemonic; /* this cannot be ':'! */
 170        const char *name;
 171} pathspec_magic[] = {
 172        { PATHSPEC_FROMTOP, '/', "top" },
 173};
 174
 175/*
 176 * Take an element of a pathspec and check for magic signatures.
 177 * Append the result to the prefix.
 178 *
 179 * For now, we only parse the syntax and throw out anything other than
 180 * "top" magic.
 181 *
 182 * NEEDSWORK: This needs to be rewritten when we start migrating
 183 * get_pathspec() users to use the "struct pathspec" interface.  For
 184 * example, a pathspec element may be marked as case-insensitive, but
 185 * the prefix part must always match literally, and a single stupid
 186 * string cannot express such a case.
 187 */
 188static const char *prefix_pathspec(const char *prefix, int prefixlen, const char *elt)
 189{
 190        unsigned magic = 0;
 191        const char *copyfrom = elt;
 192        int i;
 193
 194        if (elt[0] != ':') {
 195                ; /* nothing to do */
 196        } else if (elt[1] == '(') {
 197                /* longhand */
 198                const char *nextat;
 199                for (copyfrom = elt + 2;
 200                     *copyfrom && *copyfrom != ')';
 201                     copyfrom = nextat) {
 202                        size_t len = strcspn(copyfrom, ",)");
 203                        if (copyfrom[len] == ')')
 204                                nextat = copyfrom + len;
 205                        else
 206                                nextat = copyfrom + len + 1;
 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                        copyfrom++;
 221        } else {
 222                /* shorthand */
 223                for (copyfrom = elt + 1;
 224                     *copyfrom && *copyfrom != ':';
 225                     copyfrom++) {
 226                        char ch = *copyfrom;
 227
 228                        if (!is_pathspec_magic(ch))
 229                                break;
 230                        for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
 231                                if (pathspec_magic[i].mnemonic == ch) {
 232                                        magic |= pathspec_magic[i].bit;
 233                                        break;
 234                                }
 235                        if (ARRAY_SIZE(pathspec_magic) <= i)
 236                                die("Unimplemented pathspec magic '%c' in '%s'",
 237                                    ch, elt);
 238                }
 239                if (*copyfrom == ':')
 240                        copyfrom++;
 241        }
 242
 243        if (magic & PATHSPEC_FROMTOP)
 244                return xstrdup(copyfrom);
 245        else
 246                return prefix_path(prefix, prefixlen, copyfrom);
 247}
 248
 249const char **get_pathspec(const char *prefix, const char **pathspec)
 250{
 251        const char *entry = *pathspec;
 252        const char **src, **dst;
 253        int prefixlen;
 254
 255        if (!prefix && !entry)
 256                return NULL;
 257
 258        if (!entry) {
 259                static const char *spec[2];
 260                spec[0] = prefix;
 261                spec[1] = NULL;
 262                return spec;
 263        }
 264
 265        /* Otherwise we have to re-write the entries.. */
 266        src = pathspec;
 267        dst = pathspec;
 268        prefixlen = prefix ? strlen(prefix) : 0;
 269        while (*src) {
 270                *(dst++) = prefix_pathspec(prefix, prefixlen, *src);
 271                src++;
 272        }
 273        *dst = NULL;
 274        if (!*pathspec)
 275                return NULL;
 276        return pathspec;
 277}
 278
 279/*
 280 * Test if it looks like we're at a git directory.
 281 * We want to see:
 282 *
 283 *  - either an objects/ directory _or_ the proper
 284 *    GIT_OBJECT_DIRECTORY environment variable
 285 *  - a refs/ directory
 286 *  - either a HEAD symlink or a HEAD file that is formatted as
 287 *    a proper "ref:", or a regular file HEAD that has a properly
 288 *    formatted sha1 object name.
 289 */
 290int is_git_directory(const char *suspect)
 291{
 292        char path[PATH_MAX];
 293        size_t len = strlen(suspect);
 294
 295        if (PATH_MAX <= len + strlen("/objects"))
 296                die("Too long path: %.*s", 60, suspect);
 297        strcpy(path, suspect);
 298        if (getenv(DB_ENVIRONMENT)) {
 299                if (access(getenv(DB_ENVIRONMENT), X_OK))
 300                        return 0;
 301        }
 302        else {
 303                strcpy(path + len, "/objects");
 304                if (access(path, X_OK))
 305                        return 0;
 306        }
 307
 308        strcpy(path + len, "/refs");
 309        if (access(path, X_OK))
 310                return 0;
 311
 312        strcpy(path + len, "/HEAD");
 313        if (validate_headref(path))
 314                return 0;
 315
 316        return 1;
 317}
 318
 319int is_inside_git_dir(void)
 320{
 321        if (inside_git_dir < 0)
 322                inside_git_dir = is_inside_dir(get_git_dir());
 323        return inside_git_dir;
 324}
 325
 326int is_inside_work_tree(void)
 327{
 328        if (inside_work_tree < 0)
 329                inside_work_tree = is_inside_dir(get_git_work_tree());
 330        return inside_work_tree;
 331}
 332
 333void setup_work_tree(void)
 334{
 335        const char *work_tree, *git_dir;
 336        static int initialized = 0;
 337
 338        if (initialized)
 339                return;
 340        work_tree = get_git_work_tree();
 341        git_dir = get_git_dir();
 342        if (!is_absolute_path(git_dir))
 343                git_dir = real_path(get_git_dir());
 344        if (!work_tree || chdir(work_tree))
 345                die("This operation must be run in a work tree");
 346
 347        /*
 348         * Make sure subsequent git processes find correct worktree
 349         * if $GIT_WORK_TREE is set relative
 350         */
 351        if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 352                setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 353
 354        set_git_dir(relative_path(git_dir, work_tree));
 355        initialized = 1;
 356}
 357
 358static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 359{
 360        char repo_config[PATH_MAX+1];
 361
 362        /*
 363         * git_config() can't be used here because it calls git_pathdup()
 364         * to get $GIT_CONFIG/config. That call will make setup_git_env()
 365         * set git_dir to ".git".
 366         *
 367         * We are in gitdir setup, no git dir has been found useable yet.
 368         * Use a gentler version of git_config() to check if this repo
 369         * is a good one.
 370         */
 371        snprintf(repo_config, PATH_MAX, "%s/config", gitdir);
 372        git_config_early(check_repository_format_version, NULL, repo_config);
 373        if (GIT_REPO_VERSION < repository_format_version) {
 374                if (!nongit_ok)
 375                        die ("Expected git repo version <= %d, found %d",
 376                             GIT_REPO_VERSION, repository_format_version);
 377                warning("Expected git repo version <= %d, found %d",
 378                        GIT_REPO_VERSION, repository_format_version);
 379                warning("Please upgrade Git");
 380                *nongit_ok = -1;
 381                return -1;
 382        }
 383        return 0;
 384}
 385
 386/*
 387 * Try to read the location of the git directory from the .git file,
 388 * return path to git directory if found.
 389 */
 390const char *read_gitfile(const char *path)
 391{
 392        char *buf;
 393        char *dir;
 394        const char *slash;
 395        struct stat st;
 396        int fd;
 397        ssize_t len;
 398
 399        if (stat(path, &st))
 400                return NULL;
 401        if (!S_ISREG(st.st_mode))
 402                return NULL;
 403        fd = open(path, O_RDONLY);
 404        if (fd < 0)
 405                die_errno("Error opening '%s'", path);
 406        buf = xmalloc(st.st_size + 1);
 407        len = read_in_full(fd, buf, st.st_size);
 408        close(fd);
 409        if (len != st.st_size)
 410                die("Error reading %s", path);
 411        buf[len] = '\0';
 412        if (prefixcmp(buf, "gitdir: "))
 413                die("Invalid gitfile format: %s", path);
 414        while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 415                len--;
 416        if (len < 9)
 417                die("No path in gitfile: %s", path);
 418        buf[len] = '\0';
 419        dir = buf + 8;
 420
 421        if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
 422                size_t pathlen = slash+1 - path;
 423                size_t dirlen = pathlen + len - 8;
 424                dir = xmalloc(dirlen + 1);
 425                strncpy(dir, path, pathlen);
 426                strncpy(dir + pathlen, buf + 8, len - 8);
 427                dir[dirlen] = '\0';
 428                free(buf);
 429                buf = dir;
 430        }
 431
 432        if (!is_git_directory(dir))
 433                die("Not a git repository: %s", dir);
 434        path = real_path(dir);
 435
 436        free(buf);
 437        return path;
 438}
 439
 440static const char *setup_explicit_git_dir(const char *gitdirenv,
 441                                          char *cwd, int len,
 442                                          int *nongit_ok)
 443{
 444        const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 445        const char *worktree;
 446        char *gitfile;
 447        int offset;
 448
 449        if (PATH_MAX - 40 < strlen(gitdirenv))
 450                die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 451
 452        gitfile = (char*)read_gitfile(gitdirenv);
 453        if (gitfile) {
 454                gitfile = xstrdup(gitfile);
 455                gitdirenv = gitfile;
 456        }
 457
 458        if (!is_git_directory(gitdirenv)) {
 459                if (nongit_ok) {
 460                        *nongit_ok = 1;
 461                        free(gitfile);
 462                        return NULL;
 463                }
 464                die("Not a git repository: '%s'", gitdirenv);
 465        }
 466
 467        if (check_repository_format_gently(gitdirenv, nongit_ok)) {
 468                free(gitfile);
 469                return NULL;
 470        }
 471
 472        /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
 473        if (work_tree_env)
 474                set_git_work_tree(work_tree_env);
 475        else if (is_bare_repository_cfg > 0) {
 476                if (git_work_tree_cfg) /* #22.2, #30 */
 477                        die("core.bare and core.worktree do not make sense");
 478
 479                /* #18, #26 */
 480                set_git_dir(gitdirenv);
 481                free(gitfile);
 482                return NULL;
 483        }
 484        else if (git_work_tree_cfg) { /* #6, #14 */
 485                if (is_absolute_path(git_work_tree_cfg))
 486                        set_git_work_tree(git_work_tree_cfg);
 487                else {
 488                        char core_worktree[PATH_MAX];
 489                        if (chdir(gitdirenv))
 490                                die_errno("Could not chdir to '%s'", gitdirenv);
 491                        if (chdir(git_work_tree_cfg))
 492                                die_errno("Could not chdir to '%s'", git_work_tree_cfg);
 493                        if (!getcwd(core_worktree, PATH_MAX))
 494                                die_errno("Could not get directory '%s'", git_work_tree_cfg);
 495                        if (chdir(cwd))
 496                                die_errno("Could not come back to cwd");
 497                        set_git_work_tree(core_worktree);
 498                }
 499        }
 500        else /* #2, #10 */
 501                set_git_work_tree(".");
 502
 503        /* set_git_work_tree() must have been called by now */
 504        worktree = get_git_work_tree();
 505
 506        /* both get_git_work_tree() and cwd are already normalized */
 507        if (!strcmp(cwd, worktree)) { /* cwd == worktree */
 508                set_git_dir(gitdirenv);
 509                free(gitfile);
 510                return NULL;
 511        }
 512
 513        offset = dir_inside_of(cwd, worktree);
 514        if (offset >= 0) {      /* cwd inside worktree? */
 515                set_git_dir(real_path(gitdirenv));
 516                if (chdir(worktree))
 517                        die_errno("Could not chdir to '%s'", worktree);
 518                cwd[len++] = '/';
 519                cwd[len] = '\0';
 520                free(gitfile);
 521                return cwd + offset;
 522        }
 523
 524        /* cwd outside worktree */
 525        set_git_dir(gitdirenv);
 526        free(gitfile);
 527        return NULL;
 528}
 529
 530static const char *setup_discovered_git_dir(const char *gitdir,
 531                                            char *cwd, int offset, int len,
 532                                            int *nongit_ok)
 533{
 534        if (check_repository_format_gently(gitdir, nongit_ok))
 535                return NULL;
 536
 537        /* --work-tree is set without --git-dir; use discovered one */
 538        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 539                if (offset != len && !is_absolute_path(gitdir))
 540                        gitdir = xstrdup(real_path(gitdir));
 541                if (chdir(cwd))
 542                        die_errno("Could not come back to cwd");
 543                return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
 544        }
 545
 546        /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 547        if (is_bare_repository_cfg > 0) {
 548                set_git_dir(offset == len ? gitdir : real_path(gitdir));
 549                if (chdir(cwd))
 550                        die_errno("Could not come back to cwd");
 551                return NULL;
 552        }
 553
 554        /* #0, #1, #5, #8, #9, #12, #13 */
 555        set_git_work_tree(".");
 556        if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
 557                set_git_dir(gitdir);
 558        inside_git_dir = 0;
 559        inside_work_tree = 1;
 560        if (offset == len)
 561                return NULL;
 562
 563        /* Make "offset" point to past the '/', and add a '/' at the end */
 564        offset++;
 565        cwd[len++] = '/';
 566        cwd[len] = 0;
 567        return cwd + offset;
 568}
 569
 570/* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
 571static const char *setup_bare_git_dir(char *cwd, int offset, int len, int *nongit_ok)
 572{
 573        int root_len;
 574
 575        if (check_repository_format_gently(".", nongit_ok))
 576                return NULL;
 577
 578        /* --work-tree is set without --git-dir; use discovered one */
 579        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 580                const char *gitdir;
 581
 582                gitdir = offset == len ? "." : xmemdupz(cwd, offset);
 583                if (chdir(cwd))
 584                        die_errno("Could not come back to cwd");
 585                return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
 586        }
 587
 588        inside_git_dir = 1;
 589        inside_work_tree = 0;
 590        if (offset != len) {
 591                if (chdir(cwd))
 592                        die_errno("Cannot come back to cwd");
 593                root_len = offset_1st_component(cwd);
 594                cwd[offset > root_len ? offset : root_len] = '\0';
 595                set_git_dir(cwd);
 596        }
 597        else
 598                set_git_dir(".");
 599        return NULL;
 600}
 601
 602static const char *setup_nongit(const char *cwd, int *nongit_ok)
 603{
 604        if (!nongit_ok)
 605                die("Not a git repository (or any of the parent directories): %s", DEFAULT_GIT_DIR_ENVIRONMENT);
 606        if (chdir(cwd))
 607                die_errno("Cannot come back to cwd");
 608        *nongit_ok = 1;
 609        return NULL;
 610}
 611
 612static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
 613{
 614        struct stat buf;
 615        if (stat(path, &buf)) {
 616                die_errno("failed to stat '%*s%s%s'",
 617                                prefix_len,
 618                                prefix ? prefix : "",
 619                                prefix ? "/" : "", path);
 620        }
 621        return buf.st_dev;
 622}
 623
 624/*
 625 * A "string_list_each_func_t" function that canonicalizes an entry
 626 * from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or
 627 * discards it if unusable.
 628 */
 629static int canonicalize_ceiling_entry(struct string_list_item *item,
 630                                      void *unused)
 631{
 632        char *ceil = item->string;
 633        const char *real_path;
 634
 635        if (!*ceil || !is_absolute_path(ceil))
 636                return 0;
 637        real_path = real_path_if_valid(ceil);
 638        if (!real_path)
 639                return 0;
 640        free(item->string);
 641        item->string = xstrdup(real_path);
 642        return 1;
 643}
 644
 645/*
 646 * We cannot decide in this function whether we are in the work tree or
 647 * not, since the config can only be read _after_ this function was called.
 648 */
 649static const char *setup_git_directory_gently_1(int *nongit_ok)
 650{
 651        const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 652        struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
 653        static char cwd[PATH_MAX+1];
 654        const char *gitdirenv, *ret;
 655        char *gitfile;
 656        int len, offset, offset_parent, ceil_offset = -1;
 657        dev_t current_device = 0;
 658        int one_filesystem = 1;
 659
 660        /*
 661         * Let's assume that we are in a git repository.
 662         * If it turns out later that we are somewhere else, the value will be
 663         * updated accordingly.
 664         */
 665        if (nongit_ok)
 666                *nongit_ok = 0;
 667
 668        if (!getcwd(cwd, sizeof(cwd)-1))
 669                die_errno("Unable to read current working directory");
 670        offset = len = strlen(cwd);
 671
 672        /*
 673         * If GIT_DIR is set explicitly, we're not going
 674         * to do any discovery, but we still do repository
 675         * validation.
 676         */
 677        gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 678        if (gitdirenv)
 679                return setup_explicit_git_dir(gitdirenv, cwd, len, nongit_ok);
 680
 681        if (env_ceiling_dirs) {
 682                string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
 683                filter_string_list(&ceiling_dirs, 0,
 684                                   canonicalize_ceiling_entry, NULL);
 685                ceil_offset = longest_ancestor_length(cwd, &ceiling_dirs);
 686                string_list_clear(&ceiling_dirs, 0);
 687        }
 688
 689        if (ceil_offset < 0 && has_dos_drive_prefix(cwd))
 690                ceil_offset = 1;
 691
 692        /*
 693         * Test in the following order (relative to the cwd):
 694         * - .git (file containing "gitdir: <path>")
 695         * - .git/
 696         * - ./ (bare)
 697         * - ../.git
 698         * - ../.git/
 699         * - ../ (bare)
 700         * - ../../.git/
 701         *   etc.
 702         */
 703        one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
 704        if (one_filesystem)
 705                current_device = get_device_or_die(".", NULL, 0);
 706        for (;;) {
 707                gitfile = (char*)read_gitfile(DEFAULT_GIT_DIR_ENVIRONMENT);
 708                if (gitfile)
 709                        gitdirenv = gitfile = xstrdup(gitfile);
 710                else {
 711                        if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 712                                gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
 713                }
 714
 715                if (gitdirenv) {
 716                        ret = setup_discovered_git_dir(gitdirenv,
 717                                                       cwd, offset, len,
 718                                                       nongit_ok);
 719                        free(gitfile);
 720                        return ret;
 721                }
 722                free(gitfile);
 723
 724                if (is_git_directory("."))
 725                        return setup_bare_git_dir(cwd, offset, len, nongit_ok);
 726
 727                offset_parent = offset;
 728                while (--offset_parent > ceil_offset && cwd[offset_parent] != '/');
 729                if (offset_parent <= ceil_offset)
 730                        return setup_nongit(cwd, nongit_ok);
 731                if (one_filesystem) {
 732                        dev_t parent_device = get_device_or_die("..", cwd, offset);
 733                        if (parent_device != current_device) {
 734                                if (nongit_ok) {
 735                                        if (chdir(cwd))
 736                                                die_errno("Cannot come back to cwd");
 737                                        *nongit_ok = 1;
 738                                        return NULL;
 739                                }
 740                                cwd[offset] = '\0';
 741                                die("Not a git repository (or any parent up to mount point %s)\n"
 742                                "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).", cwd);
 743                        }
 744                }
 745                if (chdir("..")) {
 746                        cwd[offset] = '\0';
 747                        die_errno("Cannot change to '%s/..'", cwd);
 748                }
 749                offset = offset_parent;
 750        }
 751}
 752
 753const char *setup_git_directory_gently(int *nongit_ok)
 754{
 755        const char *prefix;
 756
 757        prefix = setup_git_directory_gently_1(nongit_ok);
 758        if (prefix)
 759                setenv("GIT_PREFIX", prefix, 1);
 760        else
 761                setenv("GIT_PREFIX", "", 1);
 762
 763        if (startup_info) {
 764                startup_info->have_repository = !nongit_ok || !*nongit_ok;
 765                startup_info->prefix = prefix;
 766        }
 767        return prefix;
 768}
 769
 770int git_config_perm(const char *var, const char *value)
 771{
 772        int i;
 773        char *endptr;
 774
 775        if (value == NULL)
 776                return PERM_GROUP;
 777
 778        if (!strcmp(value, "umask"))
 779                return PERM_UMASK;
 780        if (!strcmp(value, "group"))
 781                return PERM_GROUP;
 782        if (!strcmp(value, "all") ||
 783            !strcmp(value, "world") ||
 784            !strcmp(value, "everybody"))
 785                return PERM_EVERYBODY;
 786
 787        /* Parse octal numbers */
 788        i = strtol(value, &endptr, 8);
 789
 790        /* If not an octal number, maybe true/false? */
 791        if (*endptr != 0)
 792                return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
 793
 794        /*
 795         * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
 796         * a chmod value to restrict to.
 797         */
 798        switch (i) {
 799        case PERM_UMASK:               /* 0 */
 800                return PERM_UMASK;
 801        case OLD_PERM_GROUP:           /* 1 */
 802                return PERM_GROUP;
 803        case OLD_PERM_EVERYBODY:       /* 2 */
 804                return PERM_EVERYBODY;
 805        }
 806
 807        /* A filemode value was given: 0xxx */
 808
 809        if ((i & 0600) != 0600)
 810                die("Problem with core.sharedRepository filemode value "
 811                    "(0%.3o).\nThe owner of files must always have "
 812                    "read and write permissions.", i);
 813
 814        /*
 815         * Mask filemode value. Others can not get write permission.
 816         * x flags for directories are handled separately.
 817         */
 818        return -(i & 0666);
 819}
 820
 821int check_repository_format_version(const char *var, const char *value, void *cb)
 822{
 823        if (strcmp(var, "core.repositoryformatversion") == 0)
 824                repository_format_version = git_config_int(var, value);
 825        else if (strcmp(var, "core.sharedrepository") == 0)
 826                shared_repository = git_config_perm(var, value);
 827        else if (strcmp(var, "core.bare") == 0) {
 828                is_bare_repository_cfg = git_config_bool(var, value);
 829                if (is_bare_repository_cfg == 1)
 830                        inside_work_tree = -1;
 831        } else if (strcmp(var, "core.worktree") == 0) {
 832                if (!value)
 833                        return config_error_nonbool(var);
 834                free(git_work_tree_cfg);
 835                git_work_tree_cfg = xstrdup(value);
 836                inside_work_tree = -1;
 837        }
 838        return 0;
 839}
 840
 841int check_repository_format(void)
 842{
 843        return check_repository_format_gently(get_git_dir(), NULL);
 844}
 845
 846/*
 847 * Returns the "prefix", a path to the current working directory
 848 * relative to the work tree root, or NULL, if the current working
 849 * directory is not a strict subdirectory of the work tree root. The
 850 * prefix always ends with a '/' character.
 851 */
 852const char *setup_git_directory(void)
 853{
 854        return setup_git_directory_gently(NULL);
 855}
 856
 857const char *resolve_gitdir(const char *suspect)
 858{
 859        if (is_git_directory(suspect))
 860                return suspect;
 861        return read_gitfile(suspect);
 862}