setup.con commit setup: clarify error messages for file/revisions ambiguity (4d4b573)
   1#include "cache.h"
   2#include "dir.h"
   3
   4static int inside_git_dir = -1;
   5static int inside_work_tree = -1;
   6
   7static 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
  44char *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
  52int 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
  63int 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
  76static void NORETURN die_verify_filename(const char *prefix,
  77                                         const char *arg,
  78                                         int diagnose_misspelt_rev)
  79{
  80        unsigned char sha1[20];
  81        unsigned mode;
  82
  83        if (!diagnose_misspelt_rev)
  84                die("%s: no such path in the working tree.\n"
  85                    "Use 'git <command> -- <path>...' to specify paths that do not exist locally.",
  86                    arg);
  87        /*
  88         * Saying "'(icase)foo' does not exist in the index" when the
  89         * user gave us ":(icase)foo" is just stupid.  A magic pathspec
  90         * begins with a colon and is followed by a non-alnum; do not
  91         * let get_sha1_with_mode_1(only_to_die=1) to even trigger.
  92         */
  93        if (!(arg[0] == ':' && !isalnum(arg[1])))
  94                /* try a detailed diagnostic ... */
  95                get_sha1_with_mode_1(arg, sha1, &mode, 1, prefix);
  96
  97        /* ... or fall back the most general message. */
  98        die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
  99            "Use '--' to separate paths from revisions, like this:\n"
 100            "'git <command> [<revision>...] -- [<file>...]'", arg);
 101
 102}
 103
 104/*
 105 * Verify a filename that we got as an argument for a pathspec
 106 * entry. Note that a filename that begins with "-" never verifies
 107 * as true, because even if such a filename were to exist, we want
 108 * it to be preceded by the "--" marker (or we want the user to
 109 * use a format like "./-filename")
 110 *
 111 * The "diagnose_misspelt_rev" is used to provide a user-friendly
 112 * diagnosis when dying upon finding that "name" is not a pathname.
 113 * If set to 1, the diagnosis will try to diagnose "name" as an
 114 * invalid object name (e.g. HEAD:foo). If set to 0, the diagnosis
 115 * will only complain about an inexisting file.
 116 *
 117 * This function is typically called to check that a "file or rev"
 118 * argument is unambiguous. In this case, the caller will want
 119 * diagnose_misspelt_rev == 1 when verifying the first non-rev
 120 * argument (which could have been a revision), and
 121 * diagnose_misspelt_rev == 0 for the next ones (because we already
 122 * saw a filename, there's not ambiguity anymore).
 123 */
 124void verify_filename(const char *prefix,
 125                     const char *arg,
 126                     int diagnose_misspelt_rev)
 127{
 128        if (*arg == '-')
 129                die("bad flag '%s' used after filename", arg);
 130        if (check_filename(prefix, arg))
 131                return;
 132        die_verify_filename(prefix, arg, diagnose_misspelt_rev);
 133}
 134
 135/*
 136 * Opposite of the above: the command line did not have -- marker
 137 * and we parsed the arg as a refname.  It should not be interpretable
 138 * as a filename.
 139 */
 140void verify_non_filename(const char *prefix, const char *arg)
 141{
 142        if (!is_inside_work_tree() || is_inside_git_dir())
 143                return;
 144        if (*arg == '-')
 145                return; /* flag */
 146        if (!check_filename(prefix, arg))
 147                return;
 148        die("ambiguous argument '%s': both revision and filename\n"
 149            "Use '--' to separate paths from revisions, like this:\n"
 150            "'git <command> [<revision>...] -- [<file>...]'", arg);
 151}
 152
 153/*
 154 * Magic pathspec
 155 *
 156 * NEEDSWORK: These need to be moved to dir.h or even to a new
 157 * pathspec.h when we restructure get_pathspec() users to use the
 158 * "struct pathspec" interface.
 159 *
 160 * Possible future magic semantics include stuff like:
 161 *
 162 *      { PATHSPEC_NOGLOB, '!', "noglob" },
 163 *      { PATHSPEC_ICASE, '\0', "icase" },
 164 *      { PATHSPEC_RECURSIVE, '*', "recursive" },
 165 *      { PATHSPEC_REGEXP, '\0', "regexp" },
 166 *
 167 */
 168#define PATHSPEC_FROMTOP    (1<<0)
 169
 170static struct pathspec_magic {
 171        unsigned bit;
 172        char mnemonic; /* this cannot be ':'! */
 173        const char *name;
 174} pathspec_magic[] = {
 175        { PATHSPEC_FROMTOP, '/', "top" },
 176};
 177
 178/*
 179 * Take an element of a pathspec and check for magic signatures.
 180 * Append the result to the prefix.
 181 *
 182 * For now, we only parse the syntax and throw out anything other than
 183 * "top" magic.
 184 *
 185 * NEEDSWORK: This needs to be rewritten when we start migrating
 186 * get_pathspec() users to use the "struct pathspec" interface.  For
 187 * example, a pathspec element may be marked as case-insensitive, but
 188 * the prefix part must always match literally, and a single stupid
 189 * string cannot express such a case.
 190 */
 191static const char *prefix_pathspec(const char *prefix, int prefixlen, const char *elt)
 192{
 193        unsigned magic = 0;
 194        const char *copyfrom = elt;
 195        int i;
 196
 197        if (elt[0] != ':') {
 198                ; /* nothing to do */
 199        } else if (elt[1] == '(') {
 200                /* longhand */
 201                const char *nextat;
 202                for (copyfrom = elt + 2;
 203                     *copyfrom && *copyfrom != ')';
 204                     copyfrom = nextat) {
 205                        size_t len = strcspn(copyfrom, ",)");
 206                        if (copyfrom[len] == ')')
 207                                nextat = copyfrom + len;
 208                        else
 209                                nextat = copyfrom + len + 1;
 210                        if (!len)
 211                                continue;
 212                        for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
 213                                if (strlen(pathspec_magic[i].name) == len &&
 214                                    !strncmp(pathspec_magic[i].name, copyfrom, len)) {
 215                                        magic |= pathspec_magic[i].bit;
 216                                        break;
 217                                }
 218                        if (ARRAY_SIZE(pathspec_magic) <= i)
 219                                die("Invalid pathspec magic '%.*s' in '%s'",
 220                                    (int) len, copyfrom, elt);
 221                }
 222                if (*copyfrom == ')')
 223                        copyfrom++;
 224        } else {
 225                /* shorthand */
 226                for (copyfrom = elt + 1;
 227                     *copyfrom && *copyfrom != ':';
 228                     copyfrom++) {
 229                        char ch = *copyfrom;
 230
 231                        if (!is_pathspec_magic(ch))
 232                                break;
 233                        for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
 234                                if (pathspec_magic[i].mnemonic == ch) {
 235                                        magic |= pathspec_magic[i].bit;
 236                                        break;
 237                                }
 238                        if (ARRAY_SIZE(pathspec_magic) <= i)
 239                                die("Unimplemented pathspec magic '%c' in '%s'",
 240                                    ch, elt);
 241                }
 242                if (*copyfrom == ':')
 243                        copyfrom++;
 244        }
 245
 246        if (magic & PATHSPEC_FROMTOP)
 247                return xstrdup(copyfrom);
 248        else
 249                return prefix_path(prefix, prefixlen, copyfrom);
 250}
 251
 252const char **get_pathspec(const char *prefix, const char **pathspec)
 253{
 254        const char *entry = *pathspec;
 255        const char **src, **dst;
 256        int prefixlen;
 257
 258        if (!prefix && !entry)
 259                return NULL;
 260
 261        if (!entry) {
 262                static const char *spec[2];
 263                spec[0] = prefix;
 264                spec[1] = NULL;
 265                return spec;
 266        }
 267
 268        /* Otherwise we have to re-write the entries.. */
 269        src = pathspec;
 270        dst = pathspec;
 271        prefixlen = prefix ? strlen(prefix) : 0;
 272        while (*src) {
 273                *(dst++) = prefix_pathspec(prefix, prefixlen, *src);
 274                src++;
 275        }
 276        *dst = NULL;
 277        if (!*pathspec)
 278                return NULL;
 279        return pathspec;
 280}
 281
 282/*
 283 * Test if it looks like we're at a git directory.
 284 * We want to see:
 285 *
 286 *  - either an objects/ directory _or_ the proper
 287 *    GIT_OBJECT_DIRECTORY environment variable
 288 *  - a refs/ directory
 289 *  - either a HEAD symlink or a HEAD file that is formatted as
 290 *    a proper "ref:", or a regular file HEAD that has a properly
 291 *    formatted sha1 object name.
 292 */
 293int is_git_directory(const char *suspect)
 294{
 295        char path[PATH_MAX];
 296        size_t len = strlen(suspect);
 297
 298        if (PATH_MAX <= len + strlen("/objects"))
 299                die("Too long path: %.*s", 60, suspect);
 300        strcpy(path, suspect);
 301        if (getenv(DB_ENVIRONMENT)) {
 302                if (access(getenv(DB_ENVIRONMENT), X_OK))
 303                        return 0;
 304        }
 305        else {
 306                strcpy(path + len, "/objects");
 307                if (access(path, X_OK))
 308                        return 0;
 309        }
 310
 311        strcpy(path + len, "/refs");
 312        if (access(path, X_OK))
 313                return 0;
 314
 315        strcpy(path + len, "/HEAD");
 316        if (validate_headref(path))
 317                return 0;
 318
 319        return 1;
 320}
 321
 322int is_inside_git_dir(void)
 323{
 324        if (inside_git_dir < 0)
 325                inside_git_dir = is_inside_dir(get_git_dir());
 326        return inside_git_dir;
 327}
 328
 329int is_inside_work_tree(void)
 330{
 331        if (inside_work_tree < 0)
 332                inside_work_tree = is_inside_dir(get_git_work_tree());
 333        return inside_work_tree;
 334}
 335
 336void setup_work_tree(void)
 337{
 338        const char *work_tree, *git_dir;
 339        static int initialized = 0;
 340
 341        if (initialized)
 342                return;
 343        work_tree = get_git_work_tree();
 344        git_dir = get_git_dir();
 345        if (!is_absolute_path(git_dir))
 346                git_dir = real_path(get_git_dir());
 347        if (!work_tree || chdir(work_tree))
 348                die("This operation must be run in a work tree");
 349
 350        /*
 351         * Make sure subsequent git processes find correct worktree
 352         * if $GIT_WORK_TREE is set relative
 353         */
 354        if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 355                setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 356
 357        set_git_dir(relative_path(git_dir, work_tree));
 358        initialized = 1;
 359}
 360
 361static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 362{
 363        char repo_config[PATH_MAX+1];
 364
 365        /*
 366         * git_config() can't be used here because it calls git_pathdup()
 367         * to get $GIT_CONFIG/config. That call will make setup_git_env()
 368         * set git_dir to ".git".
 369         *
 370         * We are in gitdir setup, no git dir has been found useable yet.
 371         * Use a gentler version of git_config() to check if this repo
 372         * is a good one.
 373         */
 374        snprintf(repo_config, PATH_MAX, "%s/config", gitdir);
 375        git_config_early(check_repository_format_version, NULL, repo_config);
 376        if (GIT_REPO_VERSION < repository_format_version) {
 377                if (!nongit_ok)
 378                        die ("Expected git repo version <= %d, found %d",
 379                             GIT_REPO_VERSION, repository_format_version);
 380                warning("Expected git repo version <= %d, found %d",
 381                        GIT_REPO_VERSION, repository_format_version);
 382                warning("Please upgrade Git");
 383                *nongit_ok = -1;
 384                return -1;
 385        }
 386        return 0;
 387}
 388
 389/*
 390 * Try to read the location of the git directory from the .git file,
 391 * return path to git directory if found.
 392 */
 393const char *read_gitfile(const char *path)
 394{
 395        char *buf;
 396        char *dir;
 397        const char *slash;
 398        struct stat st;
 399        int fd;
 400        ssize_t len;
 401
 402        if (stat(path, &st))
 403                return NULL;
 404        if (!S_ISREG(st.st_mode))
 405                return NULL;
 406        fd = open(path, O_RDONLY);
 407        if (fd < 0)
 408                die_errno("Error opening '%s'", path);
 409        buf = xmalloc(st.st_size + 1);
 410        len = read_in_full(fd, buf, st.st_size);
 411        close(fd);
 412        if (len != st.st_size)
 413                die("Error reading %s", path);
 414        buf[len] = '\0';
 415        if (prefixcmp(buf, "gitdir: "))
 416                die("Invalid gitfile format: %s", path);
 417        while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 418                len--;
 419        if (len < 9)
 420                die("No path in gitfile: %s", path);
 421        buf[len] = '\0';
 422        dir = buf + 8;
 423
 424        if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
 425                size_t pathlen = slash+1 - path;
 426                size_t dirlen = pathlen + len - 8;
 427                dir = xmalloc(dirlen + 1);
 428                strncpy(dir, path, pathlen);
 429                strncpy(dir + pathlen, buf + 8, len - 8);
 430                dir[dirlen] = '\0';
 431                free(buf);
 432                buf = dir;
 433        }
 434
 435        if (!is_git_directory(dir))
 436                die("Not a git repository: %s", dir);
 437        path = real_path(dir);
 438
 439        free(buf);
 440        return path;
 441}
 442
 443static const char *setup_explicit_git_dir(const char *gitdirenv,
 444                                          char *cwd, int len,
 445                                          int *nongit_ok)
 446{
 447        const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 448        const char *worktree;
 449        char *gitfile;
 450        int offset;
 451
 452        if (PATH_MAX - 40 < strlen(gitdirenv))
 453                die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 454
 455        gitfile = (char*)read_gitfile(gitdirenv);
 456        if (gitfile) {
 457                gitfile = xstrdup(gitfile);
 458                gitdirenv = gitfile;
 459        }
 460
 461        if (!is_git_directory(gitdirenv)) {
 462                if (nongit_ok) {
 463                        *nongit_ok = 1;
 464                        free(gitfile);
 465                        return NULL;
 466                }
 467                die("Not a git repository: '%s'", gitdirenv);
 468        }
 469
 470        if (check_repository_format_gently(gitdirenv, nongit_ok)) {
 471                free(gitfile);
 472                return NULL;
 473        }
 474
 475        /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
 476        if (work_tree_env)
 477                set_git_work_tree(work_tree_env);
 478        else if (is_bare_repository_cfg > 0) {
 479                if (git_work_tree_cfg) /* #22.2, #30 */
 480                        die("core.bare and core.worktree do not make sense");
 481
 482                /* #18, #26 */
 483                set_git_dir(gitdirenv);
 484                free(gitfile);
 485                return NULL;
 486        }
 487        else if (git_work_tree_cfg) { /* #6, #14 */
 488                if (is_absolute_path(git_work_tree_cfg))
 489                        set_git_work_tree(git_work_tree_cfg);
 490                else {
 491                        char core_worktree[PATH_MAX];
 492                        if (chdir(gitdirenv))
 493                                die_errno("Could not chdir to '%s'", gitdirenv);
 494                        if (chdir(git_work_tree_cfg))
 495                                die_errno("Could not chdir to '%s'", git_work_tree_cfg);
 496                        if (!getcwd(core_worktree, PATH_MAX))
 497                                die_errno("Could not get directory '%s'", git_work_tree_cfg);
 498                        if (chdir(cwd))
 499                                die_errno("Could not come back to cwd");
 500                        set_git_work_tree(core_worktree);
 501                }
 502        }
 503        else /* #2, #10 */
 504                set_git_work_tree(".");
 505
 506        /* set_git_work_tree() must have been called by now */
 507        worktree = get_git_work_tree();
 508
 509        /* both get_git_work_tree() and cwd are already normalized */
 510        if (!strcmp(cwd, worktree)) { /* cwd == worktree */
 511                set_git_dir(gitdirenv);
 512                free(gitfile);
 513                return NULL;
 514        }
 515
 516        offset = dir_inside_of(cwd, worktree);
 517        if (offset >= 0) {      /* cwd inside worktree? */
 518                set_git_dir(real_path(gitdirenv));
 519                if (chdir(worktree))
 520                        die_errno("Could not chdir to '%s'", worktree);
 521                cwd[len++] = '/';
 522                cwd[len] = '\0';
 523                free(gitfile);
 524                return cwd + offset;
 525        }
 526
 527        /* cwd outside worktree */
 528        set_git_dir(gitdirenv);
 529        free(gitfile);
 530        return NULL;
 531}
 532
 533static const char *setup_discovered_git_dir(const char *gitdir,
 534                                            char *cwd, int offset, int len,
 535                                            int *nongit_ok)
 536{
 537        if (check_repository_format_gently(gitdir, nongit_ok))
 538                return NULL;
 539
 540        /* --work-tree is set without --git-dir; use discovered one */
 541        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 542                if (offset != len && !is_absolute_path(gitdir))
 543                        gitdir = xstrdup(real_path(gitdir));
 544                if (chdir(cwd))
 545                        die_errno("Could not come back to cwd");
 546                return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
 547        }
 548
 549        /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 550        if (is_bare_repository_cfg > 0) {
 551                set_git_dir(offset == len ? gitdir : real_path(gitdir));
 552                if (chdir(cwd))
 553                        die_errno("Could not come back to cwd");
 554                return NULL;
 555        }
 556
 557        /* #0, #1, #5, #8, #9, #12, #13 */
 558        set_git_work_tree(".");
 559        if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
 560                set_git_dir(gitdir);
 561        inside_git_dir = 0;
 562        inside_work_tree = 1;
 563        if (offset == len)
 564                return NULL;
 565
 566        /* Make "offset" point to past the '/', and add a '/' at the end */
 567        offset++;
 568        cwd[len++] = '/';
 569        cwd[len] = 0;
 570        return cwd + offset;
 571}
 572
 573/* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
 574static const char *setup_bare_git_dir(char *cwd, int offset, int len, int *nongit_ok)
 575{
 576        int root_len;
 577
 578        if (check_repository_format_gently(".", nongit_ok))
 579                return NULL;
 580
 581        /* --work-tree is set without --git-dir; use discovered one */
 582        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 583                const char *gitdir;
 584
 585                gitdir = offset == len ? "." : xmemdupz(cwd, offset);
 586                if (chdir(cwd))
 587                        die_errno("Could not come back to cwd");
 588                return setup_explicit_git_dir(gitdir, cwd, len, nongit_ok);
 589        }
 590
 591        inside_git_dir = 1;
 592        inside_work_tree = 0;
 593        if (offset != len) {
 594                if (chdir(cwd))
 595                        die_errno("Cannot come back to cwd");
 596                root_len = offset_1st_component(cwd);
 597                cwd[offset > root_len ? offset : root_len] = '\0';
 598                set_git_dir(cwd);
 599        }
 600        else
 601                set_git_dir(".");
 602        return NULL;
 603}
 604
 605static const char *setup_nongit(const char *cwd, int *nongit_ok)
 606{
 607        if (!nongit_ok)
 608                die("Not a git repository (or any of the parent directories): %s", DEFAULT_GIT_DIR_ENVIRONMENT);
 609        if (chdir(cwd))
 610                die_errno("Cannot come back to cwd");
 611        *nongit_ok = 1;
 612        return NULL;
 613}
 614
 615static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
 616{
 617        struct stat buf;
 618        if (stat(path, &buf)) {
 619                die_errno("failed to stat '%*s%s%s'",
 620                                prefix_len,
 621                                prefix ? prefix : "",
 622                                prefix ? "/" : "", path);
 623        }
 624        return buf.st_dev;
 625}
 626
 627/*
 628 * We cannot decide in this function whether we are in the work tree or
 629 * not, since the config can only be read _after_ this function was called.
 630 */
 631static const char *setup_git_directory_gently_1(int *nongit_ok)
 632{
 633        const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 634        static char cwd[PATH_MAX+1];
 635        const char *gitdirenv, *ret;
 636        char *gitfile;
 637        int len, offset, offset_parent, ceil_offset;
 638        dev_t current_device = 0;
 639        int one_filesystem = 1;
 640
 641        /*
 642         * Let's assume that we are in a git repository.
 643         * If it turns out later that we are somewhere else, the value will be
 644         * updated accordingly.
 645         */
 646        if (nongit_ok)
 647                *nongit_ok = 0;
 648
 649        if (!getcwd(cwd, sizeof(cwd)-1))
 650                die_errno("Unable to read current working directory");
 651        offset = len = strlen(cwd);
 652
 653        /*
 654         * If GIT_DIR is set explicitly, we're not going
 655         * to do any discovery, but we still do repository
 656         * validation.
 657         */
 658        gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 659        if (gitdirenv)
 660                return setup_explicit_git_dir(gitdirenv, cwd, len, nongit_ok);
 661
 662        ceil_offset = longest_ancestor_length(cwd, env_ceiling_dirs);
 663        if (ceil_offset < 0 && has_dos_drive_prefix(cwd))
 664                ceil_offset = 1;
 665
 666        /*
 667         * Test in the following order (relative to the cwd):
 668         * - .git (file containing "gitdir: <path>")
 669         * - .git/
 670         * - ./ (bare)
 671         * - ../.git
 672         * - ../.git/
 673         * - ../ (bare)
 674         * - ../../.git/
 675         *   etc.
 676         */
 677        one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
 678        if (one_filesystem)
 679                current_device = get_device_or_die(".", NULL, 0);
 680        for (;;) {
 681                gitfile = (char*)read_gitfile(DEFAULT_GIT_DIR_ENVIRONMENT);
 682                if (gitfile)
 683                        gitdirenv = gitfile = xstrdup(gitfile);
 684                else {
 685                        if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 686                                gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
 687                }
 688
 689                if (gitdirenv) {
 690                        ret = setup_discovered_git_dir(gitdirenv,
 691                                                       cwd, offset, len,
 692                                                       nongit_ok);
 693                        free(gitfile);
 694                        return ret;
 695                }
 696                free(gitfile);
 697
 698                if (is_git_directory("."))
 699                        return setup_bare_git_dir(cwd, offset, len, nongit_ok);
 700
 701                offset_parent = offset;
 702                while (--offset_parent > ceil_offset && cwd[offset_parent] != '/');
 703                if (offset_parent <= ceil_offset)
 704                        return setup_nongit(cwd, nongit_ok);
 705                if (one_filesystem) {
 706                        dev_t parent_device = get_device_or_die("..", cwd, offset);
 707                        if (parent_device != current_device) {
 708                                if (nongit_ok) {
 709                                        if (chdir(cwd))
 710                                                die_errno("Cannot come back to cwd");
 711                                        *nongit_ok = 1;
 712                                        return NULL;
 713                                }
 714                                cwd[offset] = '\0';
 715                                die("Not a git repository (or any parent up to mount point %s)\n"
 716                                "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).", cwd);
 717                        }
 718                }
 719                if (chdir("..")) {
 720                        cwd[offset] = '\0';
 721                        die_errno("Cannot change to '%s/..'", cwd);
 722                }
 723                offset = offset_parent;
 724        }
 725}
 726
 727const char *setup_git_directory_gently(int *nongit_ok)
 728{
 729        const char *prefix;
 730
 731        prefix = setup_git_directory_gently_1(nongit_ok);
 732        if (prefix)
 733                setenv("GIT_PREFIX", prefix, 1);
 734        else
 735                setenv("GIT_PREFIX", "", 1);
 736
 737        if (startup_info) {
 738                startup_info->have_repository = !nongit_ok || !*nongit_ok;
 739                startup_info->prefix = prefix;
 740        }
 741        return prefix;
 742}
 743
 744int git_config_perm(const char *var, const char *value)
 745{
 746        int i;
 747        char *endptr;
 748
 749        if (value == NULL)
 750                return PERM_GROUP;
 751
 752        if (!strcmp(value, "umask"))
 753                return PERM_UMASK;
 754        if (!strcmp(value, "group"))
 755                return PERM_GROUP;
 756        if (!strcmp(value, "all") ||
 757            !strcmp(value, "world") ||
 758            !strcmp(value, "everybody"))
 759                return PERM_EVERYBODY;
 760
 761        /* Parse octal numbers */
 762        i = strtol(value, &endptr, 8);
 763
 764        /* If not an octal number, maybe true/false? */
 765        if (*endptr != 0)
 766                return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
 767
 768        /*
 769         * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
 770         * a chmod value to restrict to.
 771         */
 772        switch (i) {
 773        case PERM_UMASK:               /* 0 */
 774                return PERM_UMASK;
 775        case OLD_PERM_GROUP:           /* 1 */
 776                return PERM_GROUP;
 777        case OLD_PERM_EVERYBODY:       /* 2 */
 778                return PERM_EVERYBODY;
 779        }
 780
 781        /* A filemode value was given: 0xxx */
 782
 783        if ((i & 0600) != 0600)
 784                die("Problem with core.sharedRepository filemode value "
 785                    "(0%.3o).\nThe owner of files must always have "
 786                    "read and write permissions.", i);
 787
 788        /*
 789         * Mask filemode value. Others can not get write permission.
 790         * x flags for directories are handled separately.
 791         */
 792        return -(i & 0666);
 793}
 794
 795int check_repository_format_version(const char *var, const char *value, void *cb)
 796{
 797        if (strcmp(var, "core.repositoryformatversion") == 0)
 798                repository_format_version = git_config_int(var, value);
 799        else if (strcmp(var, "core.sharedrepository") == 0)
 800                shared_repository = git_config_perm(var, value);
 801        else if (strcmp(var, "core.bare") == 0) {
 802                is_bare_repository_cfg = git_config_bool(var, value);
 803                if (is_bare_repository_cfg == 1)
 804                        inside_work_tree = -1;
 805        } else if (strcmp(var, "core.worktree") == 0) {
 806                if (!value)
 807                        return config_error_nonbool(var);
 808                free(git_work_tree_cfg);
 809                git_work_tree_cfg = xstrdup(value);
 810                inside_work_tree = -1;
 811        }
 812        return 0;
 813}
 814
 815int check_repository_format(void)
 816{
 817        return check_repository_format_gently(get_git_dir(), NULL);
 818}
 819
 820/*
 821 * Returns the "prefix", a path to the current working directory
 822 * relative to the work tree root, or NULL, if the current working
 823 * directory is not a strict subdirectory of the work tree root. The
 824 * prefix always ends with a '/' character.
 825 */
 826const char *setup_git_directory(void)
 827{
 828        return setup_git_directory_gently(NULL);
 829}
 830
 831const char *resolve_gitdir(const char *suspect)
 832{
 833        if (is_git_directory(suspect))
 834                return suspect;
 835        return read_gitfile(suspect);
 836}