setup.con commit bisect: use oid_to_hex() for converting object_id hashes to hex strings (14ced55)
   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;
   7static int work_tree_config_is_bogus;
   8
   9static struct startup_info the_startup_info;
  10struct startup_info *startup_info = &the_startup_info;
  11
  12/*
  13 * The input parameter must contain an absolute path, and it must already be
  14 * normalized.
  15 *
  16 * Find the part of an absolute path that lies inside the work tree by
  17 * dereferencing symlinks outside the work tree, for example:
  18 * /dir1/repo/dir2/file   (work tree is /dir1/repo)      -> dir2/file
  19 * /dir/file              (work tree is /)               -> dir/file
  20 * /dir/symlink1/symlink2 (symlink1 points to work tree) -> symlink2
  21 * /dir/repolink/file     (repolink points to /dir/repo) -> file
  22 * /dir/repo              (exactly equal to work tree)   -> (empty string)
  23 */
  24static int abspath_part_inside_repo(char *path)
  25{
  26        size_t len;
  27        size_t wtlen;
  28        char *path0;
  29        int off;
  30        const char *work_tree = get_git_work_tree();
  31
  32        if (!work_tree)
  33                return -1;
  34        wtlen = strlen(work_tree);
  35        len = strlen(path);
  36        off = offset_1st_component(path);
  37
  38        /* check if work tree is already the prefix */
  39        if (wtlen <= len && !strncmp(path, work_tree, wtlen)) {
  40                if (path[wtlen] == '/') {
  41                        memmove(path, path + wtlen + 1, len - wtlen);
  42                        return 0;
  43                } else if (path[wtlen - 1] == '/' || path[wtlen] == '\0') {
  44                        /* work tree is the root, or the whole path */
  45                        memmove(path, path + wtlen, len - wtlen + 1);
  46                        return 0;
  47                }
  48                /* work tree might match beginning of a symlink to work tree */
  49                off = wtlen;
  50        }
  51        path0 = path;
  52        path += off;
  53
  54        /* check each '/'-terminated level */
  55        while (*path) {
  56                path++;
  57                if (*path == '/') {
  58                        *path = '\0';
  59                        if (strcmp(real_path(path0), work_tree) == 0) {
  60                                memmove(path0, path + 1, len - (path - path0));
  61                                return 0;
  62                        }
  63                        *path = '/';
  64                }
  65        }
  66
  67        /* check whole path */
  68        if (strcmp(real_path(path0), work_tree) == 0) {
  69                *path0 = '\0';
  70                return 0;
  71        }
  72
  73        return -1;
  74}
  75
  76/*
  77 * Normalize "path", prepending the "prefix" for relative paths. If
  78 * remaining_prefix is not NULL, return the actual prefix still
  79 * remains in the path. For example, prefix = sub1/sub2/ and path is
  80 *
  81 *  foo          -> sub1/sub2/foo  (full prefix)
  82 *  ../foo       -> sub1/foo       (remaining prefix is sub1/)
  83 *  ../../bar    -> bar            (no remaining prefix)
  84 *  ../../sub1/sub2/foo -> sub1/sub2/foo (but no remaining prefix)
  85 *  `pwd`/../bar -> sub1/bar       (no remaining prefix)
  86 */
  87char *prefix_path_gently(const char *prefix, int len,
  88                         int *remaining_prefix, const char *path)
  89{
  90        const char *orig = path;
  91        char *sanitized;
  92        if (is_absolute_path(orig)) {
  93                sanitized = xmallocz(strlen(path));
  94                if (remaining_prefix)
  95                        *remaining_prefix = 0;
  96                if (normalize_path_copy_len(sanitized, path, remaining_prefix)) {
  97                        free(sanitized);
  98                        return NULL;
  99                }
 100                if (abspath_part_inside_repo(sanitized)) {
 101                        free(sanitized);
 102                        return NULL;
 103                }
 104        } else {
 105                sanitized = xstrfmt("%.*s%s", len, len ? prefix : "", path);
 106                if (remaining_prefix)
 107                        *remaining_prefix = len;
 108                if (normalize_path_copy_len(sanitized, sanitized, remaining_prefix)) {
 109                        free(sanitized);
 110                        return NULL;
 111                }
 112        }
 113        return sanitized;
 114}
 115
 116char *prefix_path(const char *prefix, int len, const char *path)
 117{
 118        char *r = prefix_path_gently(prefix, len, NULL, path);
 119        if (!r)
 120                die("'%s' is outside repository", path);
 121        return r;
 122}
 123
 124int path_inside_repo(const char *prefix, const char *path)
 125{
 126        int len = prefix ? strlen(prefix) : 0;
 127        char *r = prefix_path_gently(prefix, len, NULL, path);
 128        if (r) {
 129                free(r);
 130                return 1;
 131        }
 132        return 0;
 133}
 134
 135int check_filename(const char *prefix, const char *arg)
 136{
 137        const char *name;
 138        struct stat st;
 139
 140        if (starts_with(arg, ":/")) {
 141                if (arg[2] == '\0') /* ":/" is root dir, always exists */
 142                        return 1;
 143                name = arg + 2;
 144        } else if (prefix)
 145                name = prefix_filename(prefix, strlen(prefix), arg);
 146        else
 147                name = arg;
 148        if (!lstat(name, &st))
 149                return 1; /* file exists */
 150        if (errno == ENOENT || errno == ENOTDIR)
 151                return 0; /* file does not exist */
 152        die_errno("failed to stat '%s'", arg);
 153}
 154
 155static void NORETURN die_verify_filename(const char *prefix,
 156                                         const char *arg,
 157                                         int diagnose_misspelt_rev)
 158{
 159        if (!diagnose_misspelt_rev)
 160                die(_("%s: no such path in the working tree.\n"
 161                      "Use 'git <command> -- <path>...' to specify paths that do not exist locally."),
 162                    arg);
 163        /*
 164         * Saying "'(icase)foo' does not exist in the index" when the
 165         * user gave us ":(icase)foo" is just stupid.  A magic pathspec
 166         * begins with a colon and is followed by a non-alnum; do not
 167         * let maybe_die_on_misspelt_object_name() even trigger.
 168         */
 169        if (!(arg[0] == ':' && !isalnum(arg[1])))
 170                maybe_die_on_misspelt_object_name(arg, prefix);
 171
 172        /* ... or fall back the most general message. */
 173        die(_("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
 174              "Use '--' to separate paths from revisions, like this:\n"
 175              "'git <command> [<revision>...] -- [<file>...]'"), arg);
 176
 177}
 178
 179/*
 180 * Verify a filename that we got as an argument for a pathspec
 181 * entry. Note that a filename that begins with "-" never verifies
 182 * as true, because even if such a filename were to exist, we want
 183 * it to be preceded by the "--" marker (or we want the user to
 184 * use a format like "./-filename")
 185 *
 186 * The "diagnose_misspelt_rev" is used to provide a user-friendly
 187 * diagnosis when dying upon finding that "name" is not a pathname.
 188 * If set to 1, the diagnosis will try to diagnose "name" as an
 189 * invalid object name (e.g. HEAD:foo). If set to 0, the diagnosis
 190 * will only complain about an inexisting file.
 191 *
 192 * This function is typically called to check that a "file or rev"
 193 * argument is unambiguous. In this case, the caller will want
 194 * diagnose_misspelt_rev == 1 when verifying the first non-rev
 195 * argument (which could have been a revision), and
 196 * diagnose_misspelt_rev == 0 for the next ones (because we already
 197 * saw a filename, there's not ambiguity anymore).
 198 */
 199void verify_filename(const char *prefix,
 200                     const char *arg,
 201                     int diagnose_misspelt_rev)
 202{
 203        if (*arg == '-')
 204                die("bad flag '%s' used after filename", arg);
 205        if (check_filename(prefix, arg) || !no_wildcard(arg))
 206                return;
 207        die_verify_filename(prefix, arg, diagnose_misspelt_rev);
 208}
 209
 210/*
 211 * Opposite of the above: the command line did not have -- marker
 212 * and we parsed the arg as a refname.  It should not be interpretable
 213 * as a filename.
 214 */
 215void verify_non_filename(const char *prefix, const char *arg)
 216{
 217        if (!is_inside_work_tree() || is_inside_git_dir())
 218                return;
 219        if (*arg == '-')
 220                return; /* flag */
 221        if (!check_filename(prefix, arg))
 222                return;
 223        die(_("ambiguous argument '%s': both revision and filename\n"
 224              "Use '--' to separate paths from revisions, like this:\n"
 225              "'git <command> [<revision>...] -- [<file>...]'"), arg);
 226}
 227
 228int get_common_dir(struct strbuf *sb, const char *gitdir)
 229{
 230        const char *git_env_common_dir = getenv(GIT_COMMON_DIR_ENVIRONMENT);
 231        if (git_env_common_dir) {
 232                strbuf_addstr(sb, git_env_common_dir);
 233                return 1;
 234        } else {
 235                return get_common_dir_noenv(sb, gitdir);
 236        }
 237}
 238
 239int get_common_dir_noenv(struct strbuf *sb, const char *gitdir)
 240{
 241        struct strbuf data = STRBUF_INIT;
 242        struct strbuf path = STRBUF_INIT;
 243        int ret = 0;
 244
 245        strbuf_addf(&path, "%s/commondir", gitdir);
 246        if (file_exists(path.buf)) {
 247                if (strbuf_read_file(&data, path.buf, 0) <= 0)
 248                        die_errno(_("failed to read %s"), path.buf);
 249                while (data.len && (data.buf[data.len - 1] == '\n' ||
 250                                    data.buf[data.len - 1] == '\r'))
 251                        data.len--;
 252                data.buf[data.len] = '\0';
 253                strbuf_reset(&path);
 254                if (!is_absolute_path(data.buf))
 255                        strbuf_addf(&path, "%s/", gitdir);
 256                strbuf_addbuf(&path, &data);
 257                strbuf_add_real_path(sb, path.buf);
 258                ret = 1;
 259        } else {
 260                strbuf_addstr(sb, gitdir);
 261        }
 262
 263        strbuf_release(&data);
 264        strbuf_release(&path);
 265        return ret;
 266}
 267
 268/*
 269 * Test if it looks like we're at a git directory.
 270 * We want to see:
 271 *
 272 *  - either an objects/ directory _or_ the proper
 273 *    GIT_OBJECT_DIRECTORY environment variable
 274 *  - a refs/ directory
 275 *  - either a HEAD symlink or a HEAD file that is formatted as
 276 *    a proper "ref:", or a regular file HEAD that has a properly
 277 *    formatted sha1 object name.
 278 */
 279int is_git_directory(const char *suspect)
 280{
 281        struct strbuf path = STRBUF_INIT;
 282        int ret = 0;
 283        size_t len;
 284
 285        /* Check worktree-related signatures */
 286        strbuf_addf(&path, "%s/HEAD", suspect);
 287        if (validate_headref(path.buf))
 288                goto done;
 289
 290        strbuf_reset(&path);
 291        get_common_dir(&path, suspect);
 292        len = path.len;
 293
 294        /* Check non-worktree-related signatures */
 295        if (getenv(DB_ENVIRONMENT)) {
 296                if (access(getenv(DB_ENVIRONMENT), X_OK))
 297                        goto done;
 298        }
 299        else {
 300                strbuf_setlen(&path, len);
 301                strbuf_addstr(&path, "/objects");
 302                if (access(path.buf, X_OK))
 303                        goto done;
 304        }
 305
 306        strbuf_setlen(&path, len);
 307        strbuf_addstr(&path, "/refs");
 308        if (access(path.buf, X_OK))
 309                goto done;
 310
 311        ret = 1;
 312done:
 313        strbuf_release(&path);
 314        return ret;
 315}
 316
 317int is_nonbare_repository_dir(struct strbuf *path)
 318{
 319        int ret = 0;
 320        int gitfile_error;
 321        size_t orig_path_len = path->len;
 322        assert(orig_path_len != 0);
 323        strbuf_complete(path, '/');
 324        strbuf_addstr(path, ".git");
 325        if (read_gitfile_gently(path->buf, &gitfile_error) || is_git_directory(path->buf))
 326                ret = 1;
 327        if (gitfile_error == READ_GITFILE_ERR_OPEN_FAILED ||
 328            gitfile_error == READ_GITFILE_ERR_READ_FAILED)
 329                ret = 1;
 330        strbuf_setlen(path, orig_path_len);
 331        return ret;
 332}
 333
 334int is_inside_git_dir(void)
 335{
 336        if (inside_git_dir < 0)
 337                inside_git_dir = is_inside_dir(get_git_dir());
 338        return inside_git_dir;
 339}
 340
 341int is_inside_work_tree(void)
 342{
 343        if (inside_work_tree < 0)
 344                inside_work_tree = is_inside_dir(get_git_work_tree());
 345        return inside_work_tree;
 346}
 347
 348void setup_work_tree(void)
 349{
 350        const char *work_tree, *git_dir;
 351        static int initialized = 0;
 352
 353        if (initialized)
 354                return;
 355
 356        if (work_tree_config_is_bogus)
 357                die("unable to set up work tree using invalid config");
 358
 359        work_tree = get_git_work_tree();
 360        git_dir = get_git_dir();
 361        if (!is_absolute_path(git_dir))
 362                git_dir = real_path(get_git_dir());
 363        if (!work_tree || chdir(work_tree))
 364                die("This operation must be run in a work tree");
 365
 366        /*
 367         * Make sure subsequent git processes find correct worktree
 368         * if $GIT_WORK_TREE is set relative
 369         */
 370        if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 371                setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 372
 373        set_git_dir(remove_leading_path(git_dir, work_tree));
 374        initialized = 1;
 375}
 376
 377static int check_repo_format(const char *var, const char *value, void *vdata)
 378{
 379        struct repository_format *data = vdata;
 380        const char *ext;
 381
 382        if (strcmp(var, "core.repositoryformatversion") == 0)
 383                data->version = git_config_int(var, value);
 384        else if (skip_prefix(var, "extensions.", &ext)) {
 385                /*
 386                 * record any known extensions here; otherwise,
 387                 * we fall through to recording it as unknown, and
 388                 * check_repository_format will complain
 389                 */
 390                if (!strcmp(ext, "noop"))
 391                        ;
 392                else if (!strcmp(ext, "preciousobjects"))
 393                        data->precious_objects = git_config_bool(var, value);
 394                else
 395                        string_list_append(&data->unknown_extensions, ext);
 396        } else if (strcmp(var, "core.bare") == 0) {
 397                data->is_bare = git_config_bool(var, value);
 398        } else if (strcmp(var, "core.worktree") == 0) {
 399                if (!value)
 400                        return config_error_nonbool(var);
 401                data->work_tree = xstrdup(value);
 402        }
 403        return 0;
 404}
 405
 406static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 407{
 408        struct strbuf sb = STRBUF_INIT;
 409        struct strbuf err = STRBUF_INIT;
 410        struct repository_format candidate;
 411        int has_common;
 412
 413        has_common = get_common_dir(&sb, gitdir);
 414        strbuf_addstr(&sb, "/config");
 415        read_repository_format(&candidate, sb.buf);
 416        strbuf_release(&sb);
 417
 418        /*
 419         * For historical use of check_repository_format() in git-init,
 420         * we treat a missing config as a silent "ok", even when nongit_ok
 421         * is unset.
 422         */
 423        if (candidate.version < 0)
 424                return 0;
 425
 426        if (verify_repository_format(&candidate, &err) < 0) {
 427                if (nongit_ok) {
 428                        warning("%s", err.buf);
 429                        strbuf_release(&err);
 430                        *nongit_ok = -1;
 431                        return -1;
 432                }
 433                die("%s", err.buf);
 434        }
 435
 436        repository_format_precious_objects = candidate.precious_objects;
 437        string_list_clear(&candidate.unknown_extensions, 0);
 438        if (!has_common) {
 439                if (candidate.is_bare != -1) {
 440                        is_bare_repository_cfg = candidate.is_bare;
 441                        if (is_bare_repository_cfg == 1)
 442                                inside_work_tree = -1;
 443                }
 444                if (candidate.work_tree) {
 445                        free(git_work_tree_cfg);
 446                        git_work_tree_cfg = candidate.work_tree;
 447                        inside_work_tree = -1;
 448                }
 449        } else {
 450                free(candidate.work_tree);
 451        }
 452
 453        return 0;
 454}
 455
 456int read_repository_format(struct repository_format *format, const char *path)
 457{
 458        memset(format, 0, sizeof(*format));
 459        format->version = -1;
 460        format->is_bare = -1;
 461        string_list_init(&format->unknown_extensions, 1);
 462        git_config_from_file(check_repo_format, path, format);
 463        return format->version;
 464}
 465
 466int verify_repository_format(const struct repository_format *format,
 467                             struct strbuf *err)
 468{
 469        if (GIT_REPO_VERSION_READ < format->version) {
 470                strbuf_addf(err, _("Expected git repo version <= %d, found %d"),
 471                            GIT_REPO_VERSION_READ, format->version);
 472                return -1;
 473        }
 474
 475        if (format->version >= 1 && format->unknown_extensions.nr) {
 476                int i;
 477
 478                strbuf_addstr(err, _("unknown repository extensions found:"));
 479
 480                for (i = 0; i < format->unknown_extensions.nr; i++)
 481                        strbuf_addf(err, "\n\t%s",
 482                                    format->unknown_extensions.items[i].string);
 483                return -1;
 484        }
 485
 486        return 0;
 487}
 488
 489void read_gitfile_error_die(int error_code, const char *path, const char *dir)
 490{
 491        switch (error_code) {
 492        case READ_GITFILE_ERR_STAT_FAILED:
 493        case READ_GITFILE_ERR_NOT_A_FILE:
 494                /* non-fatal; follow return path */
 495                break;
 496        case READ_GITFILE_ERR_OPEN_FAILED:
 497                die_errno("Error opening '%s'", path);
 498        case READ_GITFILE_ERR_TOO_LARGE:
 499                die("Too large to be a .git file: '%s'", path);
 500        case READ_GITFILE_ERR_READ_FAILED:
 501                die("Error reading %s", path);
 502        case READ_GITFILE_ERR_INVALID_FORMAT:
 503                die("Invalid gitfile format: %s", path);
 504        case READ_GITFILE_ERR_NO_PATH:
 505                die("No path in gitfile: %s", path);
 506        case READ_GITFILE_ERR_NOT_A_REPO:
 507                die("Not a git repository: %s", dir);
 508        default:
 509                die("BUG: unknown error code");
 510        }
 511}
 512
 513/*
 514 * Try to read the location of the git directory from the .git file,
 515 * return path to git directory if found.
 516 *
 517 * On failure, if return_error_code is not NULL, return_error_code
 518 * will be set to an error code and NULL will be returned. If
 519 * return_error_code is NULL the function will die instead (for most
 520 * cases).
 521 */
 522const char *read_gitfile_gently(const char *path, int *return_error_code)
 523{
 524        const int max_file_size = 1 << 20;  /* 1MB */
 525        int error_code = 0;
 526        char *buf = NULL;
 527        char *dir = NULL;
 528        const char *slash;
 529        struct stat st;
 530        int fd;
 531        ssize_t len;
 532
 533        if (stat(path, &st)) {
 534                error_code = READ_GITFILE_ERR_STAT_FAILED;
 535                goto cleanup_return;
 536        }
 537        if (!S_ISREG(st.st_mode)) {
 538                error_code = READ_GITFILE_ERR_NOT_A_FILE;
 539                goto cleanup_return;
 540        }
 541        if (st.st_size > max_file_size) {
 542                error_code = READ_GITFILE_ERR_TOO_LARGE;
 543                goto cleanup_return;
 544        }
 545        fd = open(path, O_RDONLY);
 546        if (fd < 0) {
 547                error_code = READ_GITFILE_ERR_OPEN_FAILED;
 548                goto cleanup_return;
 549        }
 550        buf = xmallocz(st.st_size);
 551        len = read_in_full(fd, buf, st.st_size);
 552        close(fd);
 553        if (len != st.st_size) {
 554                error_code = READ_GITFILE_ERR_READ_FAILED;
 555                goto cleanup_return;
 556        }
 557        if (!starts_with(buf, "gitdir: ")) {
 558                error_code = READ_GITFILE_ERR_INVALID_FORMAT;
 559                goto cleanup_return;
 560        }
 561        while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 562                len--;
 563        if (len < 9) {
 564                error_code = READ_GITFILE_ERR_NO_PATH;
 565                goto cleanup_return;
 566        }
 567        buf[len] = '\0';
 568        dir = buf + 8;
 569
 570        if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
 571                size_t pathlen = slash+1 - path;
 572                dir = xstrfmt("%.*s%.*s", (int)pathlen, path,
 573                              (int)(len - 8), buf + 8);
 574                free(buf);
 575                buf = dir;
 576        }
 577        if (!is_git_directory(dir)) {
 578                error_code = READ_GITFILE_ERR_NOT_A_REPO;
 579                goto cleanup_return;
 580        }
 581        path = real_path(dir);
 582
 583cleanup_return:
 584        if (return_error_code)
 585                *return_error_code = error_code;
 586        else if (error_code)
 587                read_gitfile_error_die(error_code, path, dir);
 588
 589        free(buf);
 590        return error_code ? NULL : path;
 591}
 592
 593static const char *setup_explicit_git_dir(const char *gitdirenv,
 594                                          struct strbuf *cwd,
 595                                          int *nongit_ok)
 596{
 597        const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 598        const char *worktree;
 599        char *gitfile;
 600        int offset;
 601
 602        if (PATH_MAX - 40 < strlen(gitdirenv))
 603                die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 604
 605        gitfile = (char*)read_gitfile(gitdirenv);
 606        if (gitfile) {
 607                gitfile = xstrdup(gitfile);
 608                gitdirenv = gitfile;
 609        }
 610
 611        if (!is_git_directory(gitdirenv)) {
 612                if (nongit_ok) {
 613                        *nongit_ok = 1;
 614                        free(gitfile);
 615                        return NULL;
 616                }
 617                die("Not a git repository: '%s'", gitdirenv);
 618        }
 619
 620        if (check_repository_format_gently(gitdirenv, nongit_ok)) {
 621                free(gitfile);
 622                return NULL;
 623        }
 624
 625        /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
 626        if (work_tree_env)
 627                set_git_work_tree(work_tree_env);
 628        else if (is_bare_repository_cfg > 0) {
 629                if (git_work_tree_cfg) {
 630                        /* #22.2, #30 */
 631                        warning("core.bare and core.worktree do not make sense");
 632                        work_tree_config_is_bogus = 1;
 633                }
 634
 635                /* #18, #26 */
 636                set_git_dir(gitdirenv);
 637                free(gitfile);
 638                return NULL;
 639        }
 640        else if (git_work_tree_cfg) { /* #6, #14 */
 641                if (is_absolute_path(git_work_tree_cfg))
 642                        set_git_work_tree(git_work_tree_cfg);
 643                else {
 644                        char *core_worktree;
 645                        if (chdir(gitdirenv))
 646                                die_errno("Could not chdir to '%s'", gitdirenv);
 647                        if (chdir(git_work_tree_cfg))
 648                                die_errno("Could not chdir to '%s'", git_work_tree_cfg);
 649                        core_worktree = xgetcwd();
 650                        if (chdir(cwd->buf))
 651                                die_errno("Could not come back to cwd");
 652                        set_git_work_tree(core_worktree);
 653                        free(core_worktree);
 654                }
 655        }
 656        else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
 657                /* #16d */
 658                set_git_dir(gitdirenv);
 659                free(gitfile);
 660                return NULL;
 661        }
 662        else /* #2, #10 */
 663                set_git_work_tree(".");
 664
 665        /* set_git_work_tree() must have been called by now */
 666        worktree = get_git_work_tree();
 667
 668        /* both get_git_work_tree() and cwd are already normalized */
 669        if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */
 670                set_git_dir(gitdirenv);
 671                free(gitfile);
 672                return NULL;
 673        }
 674
 675        offset = dir_inside_of(cwd->buf, worktree);
 676        if (offset >= 0) {      /* cwd inside worktree? */
 677                set_git_dir(real_path(gitdirenv));
 678                if (chdir(worktree))
 679                        die_errno("Could not chdir to '%s'", worktree);
 680                strbuf_addch(cwd, '/');
 681                free(gitfile);
 682                return cwd->buf + offset;
 683        }
 684
 685        /* cwd outside worktree */
 686        set_git_dir(gitdirenv);
 687        free(gitfile);
 688        return NULL;
 689}
 690
 691static const char *setup_discovered_git_dir(const char *gitdir,
 692                                            struct strbuf *cwd, int offset,
 693                                            int *nongit_ok)
 694{
 695        if (check_repository_format_gently(gitdir, nongit_ok))
 696                return NULL;
 697
 698        /* --work-tree is set without --git-dir; use discovered one */
 699        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 700                if (offset != cwd->len && !is_absolute_path(gitdir))
 701                        gitdir = real_pathdup(gitdir, 1);
 702                if (chdir(cwd->buf))
 703                        die_errno("Could not come back to cwd");
 704                return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 705        }
 706
 707        /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 708        if (is_bare_repository_cfg > 0) {
 709                set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir));
 710                if (chdir(cwd->buf))
 711                        die_errno("Could not come back to cwd");
 712                return NULL;
 713        }
 714
 715        /* #0, #1, #5, #8, #9, #12, #13 */
 716        set_git_work_tree(".");
 717        if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
 718                set_git_dir(gitdir);
 719        inside_git_dir = 0;
 720        inside_work_tree = 1;
 721        if (offset == cwd->len)
 722                return NULL;
 723
 724        /* Make "offset" point to past the '/', and add a '/' at the end */
 725        offset++;
 726        strbuf_addch(cwd, '/');
 727        return cwd->buf + offset;
 728}
 729
 730/* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
 731static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
 732                                      int *nongit_ok)
 733{
 734        int root_len;
 735
 736        if (check_repository_format_gently(".", nongit_ok))
 737                return NULL;
 738
 739        setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 740
 741        /* --work-tree is set without --git-dir; use discovered one */
 742        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 743                const char *gitdir;
 744
 745                gitdir = offset == cwd->len ? "." : xmemdupz(cwd->buf, offset);
 746                if (chdir(cwd->buf))
 747                        die_errno("Could not come back to cwd");
 748                return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 749        }
 750
 751        inside_git_dir = 1;
 752        inside_work_tree = 0;
 753        if (offset != cwd->len) {
 754                if (chdir(cwd->buf))
 755                        die_errno("Cannot come back to cwd");
 756                root_len = offset_1st_component(cwd->buf);
 757                strbuf_setlen(cwd, offset > root_len ? offset : root_len);
 758                set_git_dir(cwd->buf);
 759        }
 760        else
 761                set_git_dir(".");
 762        return NULL;
 763}
 764
 765static const char *setup_nongit(const char *cwd, int *nongit_ok)
 766{
 767        if (!nongit_ok)
 768                die(_("Not a git repository (or any of the parent directories): %s"), DEFAULT_GIT_DIR_ENVIRONMENT);
 769        if (chdir(cwd))
 770                die_errno(_("Cannot come back to cwd"));
 771        *nongit_ok = 1;
 772        return NULL;
 773}
 774
 775static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
 776{
 777        struct stat buf;
 778        if (stat(path, &buf)) {
 779                die_errno("failed to stat '%*s%s%s'",
 780                                prefix_len,
 781                                prefix ? prefix : "",
 782                                prefix ? "/" : "", path);
 783        }
 784        return buf.st_dev;
 785}
 786
 787/*
 788 * A "string_list_each_func_t" function that canonicalizes an entry
 789 * from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or
 790 * discards it if unusable.  The presence of an empty entry in
 791 * GIT_CEILING_DIRECTORIES turns off canonicalization for all
 792 * subsequent entries.
 793 */
 794static int canonicalize_ceiling_entry(struct string_list_item *item,
 795                                      void *cb_data)
 796{
 797        int *empty_entry_found = cb_data;
 798        char *ceil = item->string;
 799
 800        if (!*ceil) {
 801                *empty_entry_found = 1;
 802                return 0;
 803        } else if (!is_absolute_path(ceil)) {
 804                return 0;
 805        } else if (*empty_entry_found) {
 806                /* Keep entry but do not canonicalize it */
 807                return 1;
 808        } else {
 809                char *real_path = real_pathdup(ceil, 0);
 810                if (!real_path) {
 811                        return 0;
 812                }
 813                free(item->string);
 814                item->string = real_path;
 815                return 1;
 816        }
 817}
 818
 819/*
 820 * We cannot decide in this function whether we are in the work tree or
 821 * not, since the config can only be read _after_ this function was called.
 822 */
 823static const char *setup_git_directory_gently_1(int *nongit_ok)
 824{
 825        const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 826        struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
 827        static struct strbuf cwd = STRBUF_INIT;
 828        const char *gitdirenv, *ret;
 829        char *gitfile;
 830        int offset, offset_parent, ceil_offset = -1;
 831        dev_t current_device = 0;
 832        int one_filesystem = 1;
 833
 834        /*
 835         * We may have read an incomplete configuration before
 836         * setting-up the git directory. If so, clear the cache so
 837         * that the next queries to the configuration reload complete
 838         * configuration (including the per-repo config file that we
 839         * ignored previously).
 840         */
 841        git_config_clear();
 842
 843        /*
 844         * Let's assume that we are in a git repository.
 845         * If it turns out later that we are somewhere else, the value will be
 846         * updated accordingly.
 847         */
 848        if (nongit_ok)
 849                *nongit_ok = 0;
 850
 851        if (strbuf_getcwd(&cwd))
 852                die_errno(_("Unable to read current working directory"));
 853        offset = cwd.len;
 854
 855        /*
 856         * If GIT_DIR is set explicitly, we're not going
 857         * to do any discovery, but we still do repository
 858         * validation.
 859         */
 860        gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 861        if (gitdirenv)
 862                return setup_explicit_git_dir(gitdirenv, &cwd, nongit_ok);
 863
 864        if (env_ceiling_dirs) {
 865                int empty_entry_found = 0;
 866
 867                string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
 868                filter_string_list(&ceiling_dirs, 0,
 869                                   canonicalize_ceiling_entry, &empty_entry_found);
 870                ceil_offset = longest_ancestor_length(cwd.buf, &ceiling_dirs);
 871                string_list_clear(&ceiling_dirs, 0);
 872        }
 873
 874        if (ceil_offset < 0 && has_dos_drive_prefix(cwd.buf))
 875                ceil_offset = 1;
 876
 877        /*
 878         * Test in the following order (relative to the cwd):
 879         * - .git (file containing "gitdir: <path>")
 880         * - .git/
 881         * - ./ (bare)
 882         * - ../.git
 883         * - ../.git/
 884         * - ../ (bare)
 885         * - ../../.git/
 886         *   etc.
 887         */
 888        one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
 889        if (one_filesystem)
 890                current_device = get_device_or_die(".", NULL, 0);
 891        for (;;) {
 892                gitfile = (char*)read_gitfile(DEFAULT_GIT_DIR_ENVIRONMENT);
 893                if (gitfile)
 894                        gitdirenv = gitfile = xstrdup(gitfile);
 895                else {
 896                        if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 897                                gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
 898                }
 899
 900                if (gitdirenv) {
 901                        ret = setup_discovered_git_dir(gitdirenv,
 902                                                       &cwd, offset,
 903                                                       nongit_ok);
 904                        free(gitfile);
 905                        return ret;
 906                }
 907                free(gitfile);
 908
 909                if (is_git_directory("."))
 910                        return setup_bare_git_dir(&cwd, offset, nongit_ok);
 911
 912                offset_parent = offset;
 913                while (--offset_parent > ceil_offset && cwd.buf[offset_parent] != '/');
 914                if (offset_parent <= ceil_offset)
 915                        return setup_nongit(cwd.buf, nongit_ok);
 916                if (one_filesystem) {
 917                        dev_t parent_device = get_device_or_die("..", cwd.buf,
 918                                                                offset);
 919                        if (parent_device != current_device) {
 920                                if (nongit_ok) {
 921                                        if (chdir(cwd.buf))
 922                                                die_errno(_("Cannot come back to cwd"));
 923                                        *nongit_ok = 1;
 924                                        return NULL;
 925                                }
 926                                strbuf_setlen(&cwd, offset);
 927                                die(_("Not a git repository (or any parent up to mount point %s)\n"
 928                                "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set)."),
 929                                    cwd.buf);
 930                        }
 931                }
 932                if (chdir("..")) {
 933                        strbuf_setlen(&cwd, offset);
 934                        die_errno(_("Cannot change to '%s/..'"), cwd.buf);
 935                }
 936                offset = offset_parent;
 937        }
 938}
 939
 940const char *setup_git_directory_gently(int *nongit_ok)
 941{
 942        const char *prefix;
 943
 944        prefix = setup_git_directory_gently_1(nongit_ok);
 945        if (prefix)
 946                setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
 947        else
 948                setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
 949
 950        startup_info->have_repository = !nongit_ok || !*nongit_ok;
 951        startup_info->prefix = prefix;
 952
 953        return prefix;
 954}
 955
 956int git_config_perm(const char *var, const char *value)
 957{
 958        int i;
 959        char *endptr;
 960
 961        if (value == NULL)
 962                return PERM_GROUP;
 963
 964        if (!strcmp(value, "umask"))
 965                return PERM_UMASK;
 966        if (!strcmp(value, "group"))
 967                return PERM_GROUP;
 968        if (!strcmp(value, "all") ||
 969            !strcmp(value, "world") ||
 970            !strcmp(value, "everybody"))
 971                return PERM_EVERYBODY;
 972
 973        /* Parse octal numbers */
 974        i = strtol(value, &endptr, 8);
 975
 976        /* If not an octal number, maybe true/false? */
 977        if (*endptr != 0)
 978                return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
 979
 980        /*
 981         * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
 982         * a chmod value to restrict to.
 983         */
 984        switch (i) {
 985        case PERM_UMASK:               /* 0 */
 986                return PERM_UMASK;
 987        case OLD_PERM_GROUP:           /* 1 */
 988                return PERM_GROUP;
 989        case OLD_PERM_EVERYBODY:       /* 2 */
 990                return PERM_EVERYBODY;
 991        }
 992
 993        /* A filemode value was given: 0xxx */
 994
 995        if ((i & 0600) != 0600)
 996                die(_("Problem with core.sharedRepository filemode value "
 997                    "(0%.3o).\nThe owner of files must always have "
 998                    "read and write permissions."), i);
 999
1000        /*
1001         * Mask filemode value. Others can not get write permission.
1002         * x flags for directories are handled separately.
1003         */
1004        return -(i & 0666);
1005}
1006
1007void check_repository_format(void)
1008{
1009        check_repository_format_gently(get_git_dir(), NULL);
1010        startup_info->have_repository = 1;
1011}
1012
1013/*
1014 * Returns the "prefix", a path to the current working directory
1015 * relative to the work tree root, or NULL, if the current working
1016 * directory is not a strict subdirectory of the work tree root. The
1017 * prefix always ends with a '/' character.
1018 */
1019const char *setup_git_directory(void)
1020{
1021        return setup_git_directory_gently(NULL);
1022}
1023
1024const char *resolve_gitdir_gently(const char *suspect, int *return_error_code)
1025{
1026        if (is_git_directory(suspect))
1027                return suspect;
1028        return read_gitfile_gently(suspect, return_error_code);
1029}
1030
1031/* if any standard file descriptor is missing open it to /dev/null */
1032void sanitize_stdfds(void)
1033{
1034        int fd = open("/dev/null", O_RDWR, 0);
1035        while (fd != -1 && fd < 2)
1036                fd = dup(fd);
1037        if (fd == -1)
1038                die_errno("open /dev/null or dup failed");
1039        if (fd > 2)
1040                close(fd);
1041}
1042
1043int daemonize(void)
1044{
1045#ifdef NO_POSIX_GOODIES
1046        errno = ENOSYS;
1047        return -1;
1048#else
1049        switch (fork()) {
1050                case 0:
1051                        break;
1052                case -1:
1053                        die_errno("fork failed");
1054                default:
1055                        exit(0);
1056        }
1057        if (setsid() == -1)
1058                die_errno("setsid failed");
1059        close(0);
1060        close(1);
1061        close(2);
1062        sanitize_stdfds();
1063        return 0;
1064#endif
1065}