setup.con commit Merge branch 'rs/c-auto-resets-attributes' (578e602)
   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_addstr(sb, real_path(path.buf));
 258                ret = 1;
 259        } else
 260                strbuf_addstr(sb, gitdir);
 261        strbuf_release(&data);
 262        strbuf_release(&path);
 263        return ret;
 264}
 265
 266/*
 267 * Test if it looks like we're at a git directory.
 268 * We want to see:
 269 *
 270 *  - either an objects/ directory _or_ the proper
 271 *    GIT_OBJECT_DIRECTORY environment variable
 272 *  - a refs/ directory
 273 *  - either a HEAD symlink or a HEAD file that is formatted as
 274 *    a proper "ref:", or a regular file HEAD that has a properly
 275 *    formatted sha1 object name.
 276 */
 277int is_git_directory(const char *suspect)
 278{
 279        struct strbuf path = STRBUF_INIT;
 280        int ret = 0;
 281        size_t len;
 282
 283        /* Check worktree-related signatures */
 284        strbuf_addf(&path, "%s/HEAD", suspect);
 285        if (validate_headref(path.buf))
 286                goto done;
 287
 288        strbuf_reset(&path);
 289        get_common_dir(&path, suspect);
 290        len = path.len;
 291
 292        /* Check non-worktree-related signatures */
 293        if (getenv(DB_ENVIRONMENT)) {
 294                if (access(getenv(DB_ENVIRONMENT), X_OK))
 295                        goto done;
 296        }
 297        else {
 298                strbuf_setlen(&path, len);
 299                strbuf_addstr(&path, "/objects");
 300                if (access(path.buf, X_OK))
 301                        goto done;
 302        }
 303
 304        strbuf_setlen(&path, len);
 305        strbuf_addstr(&path, "/refs");
 306        if (access(path.buf, X_OK))
 307                goto done;
 308
 309        ret = 1;
 310done:
 311        strbuf_release(&path);
 312        return ret;
 313}
 314
 315int is_nonbare_repository_dir(struct strbuf *path)
 316{
 317        int ret = 0;
 318        int gitfile_error;
 319        size_t orig_path_len = path->len;
 320        assert(orig_path_len != 0);
 321        strbuf_complete(path, '/');
 322        strbuf_addstr(path, ".git");
 323        if (read_gitfile_gently(path->buf, &gitfile_error) || is_git_directory(path->buf))
 324                ret = 1;
 325        if (gitfile_error == READ_GITFILE_ERR_OPEN_FAILED ||
 326            gitfile_error == READ_GITFILE_ERR_READ_FAILED)
 327                ret = 1;
 328        strbuf_setlen(path, orig_path_len);
 329        return ret;
 330}
 331
 332int is_inside_git_dir(void)
 333{
 334        if (inside_git_dir < 0)
 335                inside_git_dir = is_inside_dir(get_git_dir());
 336        return inside_git_dir;
 337}
 338
 339int is_inside_work_tree(void)
 340{
 341        if (inside_work_tree < 0)
 342                inside_work_tree = is_inside_dir(get_git_work_tree());
 343        return inside_work_tree;
 344}
 345
 346void setup_work_tree(void)
 347{
 348        const char *work_tree, *git_dir;
 349        static int initialized = 0;
 350
 351        if (initialized)
 352                return;
 353
 354        if (work_tree_config_is_bogus)
 355                die("unable to set up work tree using invalid config");
 356
 357        work_tree = get_git_work_tree();
 358        git_dir = get_git_dir();
 359        if (!is_absolute_path(git_dir))
 360                git_dir = real_path(get_git_dir());
 361        if (!work_tree || chdir(work_tree))
 362                die("This operation must be run in a work tree");
 363
 364        /*
 365         * Make sure subsequent git processes find correct worktree
 366         * if $GIT_WORK_TREE is set relative
 367         */
 368        if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 369                setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 370
 371        set_git_dir(remove_leading_path(git_dir, work_tree));
 372        initialized = 1;
 373}
 374
 375static int check_repo_format(const char *var, const char *value, void *vdata)
 376{
 377        struct repository_format *data = vdata;
 378        const char *ext;
 379
 380        if (strcmp(var, "core.repositoryformatversion") == 0)
 381                data->version = git_config_int(var, value);
 382        else if (skip_prefix(var, "extensions.", &ext)) {
 383                /*
 384                 * record any known extensions here; otherwise,
 385                 * we fall through to recording it as unknown, and
 386                 * check_repository_format will complain
 387                 */
 388                if (!strcmp(ext, "noop"))
 389                        ;
 390                else if (!strcmp(ext, "preciousobjects"))
 391                        data->precious_objects = git_config_bool(var, value);
 392                else
 393                        string_list_append(&data->unknown_extensions, ext);
 394        } else if (strcmp(var, "core.bare") == 0) {
 395                data->is_bare = git_config_bool(var, value);
 396        } else if (strcmp(var, "core.worktree") == 0) {
 397                if (!value)
 398                        return config_error_nonbool(var);
 399                data->work_tree = xstrdup(value);
 400        }
 401        return 0;
 402}
 403
 404static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 405{
 406        struct strbuf sb = STRBUF_INIT;
 407        struct strbuf err = STRBUF_INIT;
 408        struct repository_format candidate;
 409        int has_common;
 410
 411        has_common = get_common_dir(&sb, gitdir);
 412        strbuf_addstr(&sb, "/config");
 413        read_repository_format(&candidate, sb.buf);
 414        strbuf_release(&sb);
 415
 416        /*
 417         * For historical use of check_repository_format() in git-init,
 418         * we treat a missing config as a silent "ok", even when nongit_ok
 419         * is unset.
 420         */
 421        if (candidate.version < 0)
 422                return 0;
 423
 424        if (verify_repository_format(&candidate, &err) < 0) {
 425                if (nongit_ok) {
 426                        warning("%s", err.buf);
 427                        strbuf_release(&err);
 428                        *nongit_ok = -1;
 429                        return -1;
 430                }
 431                die("%s", err.buf);
 432        }
 433
 434        repository_format_precious_objects = candidate.precious_objects;
 435        string_list_clear(&candidate.unknown_extensions, 0);
 436        if (!has_common) {
 437                if (candidate.is_bare != -1) {
 438                        is_bare_repository_cfg = candidate.is_bare;
 439                        if (is_bare_repository_cfg == 1)
 440                                inside_work_tree = -1;
 441                }
 442                if (candidate.work_tree) {
 443                        free(git_work_tree_cfg);
 444                        git_work_tree_cfg = candidate.work_tree;
 445                        inside_work_tree = -1;
 446                }
 447        } else {
 448                free(candidate.work_tree);
 449        }
 450
 451        return 0;
 452}
 453
 454int read_repository_format(struct repository_format *format, const char *path)
 455{
 456        memset(format, 0, sizeof(*format));
 457        format->version = -1;
 458        format->is_bare = -1;
 459        string_list_init(&format->unknown_extensions, 1);
 460        git_config_from_file(check_repo_format, path, format);
 461        return format->version;
 462}
 463
 464int verify_repository_format(const struct repository_format *format,
 465                             struct strbuf *err)
 466{
 467        if (GIT_REPO_VERSION_READ < format->version) {
 468                strbuf_addf(err, _("Expected git repo version <= %d, found %d"),
 469                            GIT_REPO_VERSION_READ, format->version);
 470                return -1;
 471        }
 472
 473        if (format->version >= 1 && format->unknown_extensions.nr) {
 474                int i;
 475
 476                strbuf_addstr(err, _("unknown repository extensions found:"));
 477
 478                for (i = 0; i < format->unknown_extensions.nr; i++)
 479                        strbuf_addf(err, "\n\t%s",
 480                                    format->unknown_extensions.items[i].string);
 481                return -1;
 482        }
 483
 484        return 0;
 485}
 486
 487/*
 488 * Try to read the location of the git directory from the .git file,
 489 * return path to git directory if found.
 490 *
 491 * On failure, if return_error_code is not NULL, return_error_code
 492 * will be set to an error code and NULL will be returned. If
 493 * return_error_code is NULL the function will die instead (for most
 494 * cases).
 495 */
 496const char *read_gitfile_gently(const char *path, int *return_error_code)
 497{
 498        const int max_file_size = 1 << 20;  /* 1MB */
 499        int error_code = 0;
 500        char *buf = NULL;
 501        char *dir = NULL;
 502        const char *slash;
 503        struct stat st;
 504        int fd;
 505        ssize_t len;
 506
 507        if (stat(path, &st)) {
 508                error_code = READ_GITFILE_ERR_STAT_FAILED;
 509                goto cleanup_return;
 510        }
 511        if (!S_ISREG(st.st_mode)) {
 512                error_code = READ_GITFILE_ERR_NOT_A_FILE;
 513                goto cleanup_return;
 514        }
 515        if (st.st_size > max_file_size) {
 516                error_code = READ_GITFILE_ERR_TOO_LARGE;
 517                goto cleanup_return;
 518        }
 519        fd = open(path, O_RDONLY);
 520        if (fd < 0) {
 521                error_code = READ_GITFILE_ERR_OPEN_FAILED;
 522                goto cleanup_return;
 523        }
 524        buf = xmallocz(st.st_size);
 525        len = read_in_full(fd, buf, st.st_size);
 526        close(fd);
 527        if (len != st.st_size) {
 528                error_code = READ_GITFILE_ERR_READ_FAILED;
 529                goto cleanup_return;
 530        }
 531        if (!starts_with(buf, "gitdir: ")) {
 532                error_code = READ_GITFILE_ERR_INVALID_FORMAT;
 533                goto cleanup_return;
 534        }
 535        while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 536                len--;
 537        if (len < 9) {
 538                error_code = READ_GITFILE_ERR_NO_PATH;
 539                goto cleanup_return;
 540        }
 541        buf[len] = '\0';
 542        dir = buf + 8;
 543
 544        if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
 545                size_t pathlen = slash+1 - path;
 546                dir = xstrfmt("%.*s%.*s", (int)pathlen, path,
 547                              (int)(len - 8), buf + 8);
 548                free(buf);
 549                buf = dir;
 550        }
 551        if (!is_git_directory(dir)) {
 552                error_code = READ_GITFILE_ERR_NOT_A_REPO;
 553                goto cleanup_return;
 554        }
 555        path = real_path(dir);
 556
 557cleanup_return:
 558        if (return_error_code)
 559                *return_error_code = error_code;
 560        else if (error_code) {
 561                switch (error_code) {
 562                case READ_GITFILE_ERR_STAT_FAILED:
 563                case READ_GITFILE_ERR_NOT_A_FILE:
 564                        /* non-fatal; follow return path */
 565                        break;
 566                case READ_GITFILE_ERR_OPEN_FAILED:
 567                        die_errno("Error opening '%s'", path);
 568                case READ_GITFILE_ERR_TOO_LARGE:
 569                        die("Too large to be a .git file: '%s'", path);
 570                case READ_GITFILE_ERR_READ_FAILED:
 571                        die("Error reading %s", path);
 572                case READ_GITFILE_ERR_INVALID_FORMAT:
 573                        die("Invalid gitfile format: %s", path);
 574                case READ_GITFILE_ERR_NO_PATH:
 575                        die("No path in gitfile: %s", path);
 576                case READ_GITFILE_ERR_NOT_A_REPO:
 577                        die("Not a git repository: %s", dir);
 578                default:
 579                        assert(0);
 580                }
 581        }
 582
 583        free(buf);
 584        return error_code ? NULL : path;
 585}
 586
 587static const char *setup_explicit_git_dir(const char *gitdirenv,
 588                                          struct strbuf *cwd,
 589                                          int *nongit_ok)
 590{
 591        const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 592        const char *worktree;
 593        char *gitfile;
 594        int offset;
 595
 596        if (PATH_MAX - 40 < strlen(gitdirenv))
 597                die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 598
 599        gitfile = (char*)read_gitfile(gitdirenv);
 600        if (gitfile) {
 601                gitfile = xstrdup(gitfile);
 602                gitdirenv = gitfile;
 603        }
 604
 605        if (!is_git_directory(gitdirenv)) {
 606                if (nongit_ok) {
 607                        *nongit_ok = 1;
 608                        free(gitfile);
 609                        return NULL;
 610                }
 611                die("Not a git repository: '%s'", gitdirenv);
 612        }
 613
 614        if (check_repository_format_gently(gitdirenv, nongit_ok)) {
 615                free(gitfile);
 616                return NULL;
 617        }
 618
 619        /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
 620        if (work_tree_env)
 621                set_git_work_tree(work_tree_env);
 622        else if (is_bare_repository_cfg > 0) {
 623                if (git_work_tree_cfg) {
 624                        /* #22.2, #30 */
 625                        warning("core.bare and core.worktree do not make sense");
 626                        work_tree_config_is_bogus = 1;
 627                }
 628
 629                /* #18, #26 */
 630                set_git_dir(gitdirenv);
 631                free(gitfile);
 632                return NULL;
 633        }
 634        else if (git_work_tree_cfg) { /* #6, #14 */
 635                if (is_absolute_path(git_work_tree_cfg))
 636                        set_git_work_tree(git_work_tree_cfg);
 637                else {
 638                        char *core_worktree;
 639                        if (chdir(gitdirenv))
 640                                die_errno("Could not chdir to '%s'", gitdirenv);
 641                        if (chdir(git_work_tree_cfg))
 642                                die_errno("Could not chdir to '%s'", git_work_tree_cfg);
 643                        core_worktree = xgetcwd();
 644                        if (chdir(cwd->buf))
 645                                die_errno("Could not come back to cwd");
 646                        set_git_work_tree(core_worktree);
 647                        free(core_worktree);
 648                }
 649        }
 650        else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
 651                /* #16d */
 652                set_git_dir(gitdirenv);
 653                free(gitfile);
 654                return NULL;
 655        }
 656        else /* #2, #10 */
 657                set_git_work_tree(".");
 658
 659        /* set_git_work_tree() must have been called by now */
 660        worktree = get_git_work_tree();
 661
 662        /* both get_git_work_tree() and cwd are already normalized */
 663        if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */
 664                set_git_dir(gitdirenv);
 665                free(gitfile);
 666                return NULL;
 667        }
 668
 669        offset = dir_inside_of(cwd->buf, worktree);
 670        if (offset >= 0) {      /* cwd inside worktree? */
 671                set_git_dir(real_path(gitdirenv));
 672                if (chdir(worktree))
 673                        die_errno("Could not chdir to '%s'", worktree);
 674                strbuf_addch(cwd, '/');
 675                free(gitfile);
 676                return cwd->buf + offset;
 677        }
 678
 679        /* cwd outside worktree */
 680        set_git_dir(gitdirenv);
 681        free(gitfile);
 682        return NULL;
 683}
 684
 685static const char *setup_discovered_git_dir(const char *gitdir,
 686                                            struct strbuf *cwd, int offset,
 687                                            int *nongit_ok)
 688{
 689        if (check_repository_format_gently(gitdir, nongit_ok))
 690                return NULL;
 691
 692        /* --work-tree is set without --git-dir; use discovered one */
 693        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 694                if (offset != cwd->len && !is_absolute_path(gitdir))
 695                        gitdir = xstrdup(real_path(gitdir));
 696                if (chdir(cwd->buf))
 697                        die_errno("Could not come back to cwd");
 698                return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 699        }
 700
 701        /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 702        if (is_bare_repository_cfg > 0) {
 703                set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir));
 704                if (chdir(cwd->buf))
 705                        die_errno("Could not come back to cwd");
 706                return NULL;
 707        }
 708
 709        /* #0, #1, #5, #8, #9, #12, #13 */
 710        set_git_work_tree(".");
 711        if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
 712                set_git_dir(gitdir);
 713        inside_git_dir = 0;
 714        inside_work_tree = 1;
 715        if (offset == cwd->len)
 716                return NULL;
 717
 718        /* Make "offset" point to past the '/', and add a '/' at the end */
 719        offset++;
 720        strbuf_addch(cwd, '/');
 721        return cwd->buf + offset;
 722}
 723
 724/* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
 725static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
 726                                      int *nongit_ok)
 727{
 728        int root_len;
 729
 730        if (check_repository_format_gently(".", nongit_ok))
 731                return NULL;
 732
 733        setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 734
 735        /* --work-tree is set without --git-dir; use discovered one */
 736        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 737                const char *gitdir;
 738
 739                gitdir = offset == cwd->len ? "." : xmemdupz(cwd->buf, offset);
 740                if (chdir(cwd->buf))
 741                        die_errno("Could not come back to cwd");
 742                return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 743        }
 744
 745        inside_git_dir = 1;
 746        inside_work_tree = 0;
 747        if (offset != cwd->len) {
 748                if (chdir(cwd->buf))
 749                        die_errno("Cannot come back to cwd");
 750                root_len = offset_1st_component(cwd->buf);
 751                strbuf_setlen(cwd, offset > root_len ? offset : root_len);
 752                set_git_dir(cwd->buf);
 753        }
 754        else
 755                set_git_dir(".");
 756        return NULL;
 757}
 758
 759static const char *setup_nongit(const char *cwd, int *nongit_ok)
 760{
 761        if (!nongit_ok)
 762                die(_("Not a git repository (or any of the parent directories): %s"), DEFAULT_GIT_DIR_ENVIRONMENT);
 763        if (chdir(cwd))
 764                die_errno(_("Cannot come back to cwd"));
 765        *nongit_ok = 1;
 766        return NULL;
 767}
 768
 769static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
 770{
 771        struct stat buf;
 772        if (stat(path, &buf)) {
 773                die_errno("failed to stat '%*s%s%s'",
 774                                prefix_len,
 775                                prefix ? prefix : "",
 776                                prefix ? "/" : "", path);
 777        }
 778        return buf.st_dev;
 779}
 780
 781/*
 782 * A "string_list_each_func_t" function that canonicalizes an entry
 783 * from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or
 784 * discards it if unusable.  The presence of an empty entry in
 785 * GIT_CEILING_DIRECTORIES turns off canonicalization for all
 786 * subsequent entries.
 787 */
 788static int canonicalize_ceiling_entry(struct string_list_item *item,
 789                                      void *cb_data)
 790{
 791        int *empty_entry_found = cb_data;
 792        char *ceil = item->string;
 793
 794        if (!*ceil) {
 795                *empty_entry_found = 1;
 796                return 0;
 797        } else if (!is_absolute_path(ceil)) {
 798                return 0;
 799        } else if (*empty_entry_found) {
 800                /* Keep entry but do not canonicalize it */
 801                return 1;
 802        } else {
 803                const char *real_path = real_path_if_valid(ceil);
 804                if (!real_path)
 805                        return 0;
 806                free(item->string);
 807                item->string = xstrdup(real_path);
 808                return 1;
 809        }
 810}
 811
 812/*
 813 * We cannot decide in this function whether we are in the work tree or
 814 * not, since the config can only be read _after_ this function was called.
 815 */
 816static const char *setup_git_directory_gently_1(int *nongit_ok)
 817{
 818        const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 819        struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
 820        static struct strbuf cwd = STRBUF_INIT;
 821        const char *gitdirenv, *ret;
 822        char *gitfile;
 823        int offset, offset_parent, ceil_offset = -1;
 824        dev_t current_device = 0;
 825        int one_filesystem = 1;
 826
 827        /*
 828         * We may have read an incomplete configuration before
 829         * setting-up the git directory. If so, clear the cache so
 830         * that the next queries to the configuration reload complete
 831         * configuration (including the per-repo config file that we
 832         * ignored previously).
 833         */
 834        git_config_clear();
 835
 836        /*
 837         * Let's assume that we are in a git repository.
 838         * If it turns out later that we are somewhere else, the value will be
 839         * updated accordingly.
 840         */
 841        if (nongit_ok)
 842                *nongit_ok = 0;
 843
 844        if (strbuf_getcwd(&cwd))
 845                die_errno(_("Unable to read current working directory"));
 846        offset = cwd.len;
 847
 848        /*
 849         * If GIT_DIR is set explicitly, we're not going
 850         * to do any discovery, but we still do repository
 851         * validation.
 852         */
 853        gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 854        if (gitdirenv)
 855                return setup_explicit_git_dir(gitdirenv, &cwd, nongit_ok);
 856
 857        if (env_ceiling_dirs) {
 858                int empty_entry_found = 0;
 859
 860                string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
 861                filter_string_list(&ceiling_dirs, 0,
 862                                   canonicalize_ceiling_entry, &empty_entry_found);
 863                ceil_offset = longest_ancestor_length(cwd.buf, &ceiling_dirs);
 864                string_list_clear(&ceiling_dirs, 0);
 865        }
 866
 867        if (ceil_offset < 0 && has_dos_drive_prefix(cwd.buf))
 868                ceil_offset = 1;
 869
 870        /*
 871         * Test in the following order (relative to the cwd):
 872         * - .git (file containing "gitdir: <path>")
 873         * - .git/
 874         * - ./ (bare)
 875         * - ../.git
 876         * - ../.git/
 877         * - ../ (bare)
 878         * - ../../.git/
 879         *   etc.
 880         */
 881        one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
 882        if (one_filesystem)
 883                current_device = get_device_or_die(".", NULL, 0);
 884        for (;;) {
 885                gitfile = (char*)read_gitfile(DEFAULT_GIT_DIR_ENVIRONMENT);
 886                if (gitfile)
 887                        gitdirenv = gitfile = xstrdup(gitfile);
 888                else {
 889                        if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 890                                gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
 891                }
 892
 893                if (gitdirenv) {
 894                        ret = setup_discovered_git_dir(gitdirenv,
 895                                                       &cwd, offset,
 896                                                       nongit_ok);
 897                        free(gitfile);
 898                        return ret;
 899                }
 900                free(gitfile);
 901
 902                if (is_git_directory("."))
 903                        return setup_bare_git_dir(&cwd, offset, nongit_ok);
 904
 905                offset_parent = offset;
 906                while (--offset_parent > ceil_offset && cwd.buf[offset_parent] != '/');
 907                if (offset_parent <= ceil_offset)
 908                        return setup_nongit(cwd.buf, nongit_ok);
 909                if (one_filesystem) {
 910                        dev_t parent_device = get_device_or_die("..", cwd.buf,
 911                                                                offset);
 912                        if (parent_device != current_device) {
 913                                if (nongit_ok) {
 914                                        if (chdir(cwd.buf))
 915                                                die_errno(_("Cannot come back to cwd"));
 916                                        *nongit_ok = 1;
 917                                        return NULL;
 918                                }
 919                                strbuf_setlen(&cwd, offset);
 920                                die(_("Not a git repository (or any parent up to mount point %s)\n"
 921                                "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set)."),
 922                                    cwd.buf);
 923                        }
 924                }
 925                if (chdir("..")) {
 926                        strbuf_setlen(&cwd, offset);
 927                        die_errno(_("Cannot change to '%s/..'"), cwd.buf);
 928                }
 929                offset = offset_parent;
 930        }
 931}
 932
 933const char *setup_git_directory_gently(int *nongit_ok)
 934{
 935        const char *prefix;
 936
 937        prefix = setup_git_directory_gently_1(nongit_ok);
 938        if (prefix)
 939                setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
 940        else
 941                setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
 942
 943        startup_info->have_repository = !nongit_ok || !*nongit_ok;
 944        startup_info->prefix = prefix;
 945
 946        return prefix;
 947}
 948
 949int git_config_perm(const char *var, const char *value)
 950{
 951        int i;
 952        char *endptr;
 953
 954        if (value == NULL)
 955                return PERM_GROUP;
 956
 957        if (!strcmp(value, "umask"))
 958                return PERM_UMASK;
 959        if (!strcmp(value, "group"))
 960                return PERM_GROUP;
 961        if (!strcmp(value, "all") ||
 962            !strcmp(value, "world") ||
 963            !strcmp(value, "everybody"))
 964                return PERM_EVERYBODY;
 965
 966        /* Parse octal numbers */
 967        i = strtol(value, &endptr, 8);
 968
 969        /* If not an octal number, maybe true/false? */
 970        if (*endptr != 0)
 971                return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
 972
 973        /*
 974         * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
 975         * a chmod value to restrict to.
 976         */
 977        switch (i) {
 978        case PERM_UMASK:               /* 0 */
 979                return PERM_UMASK;
 980        case OLD_PERM_GROUP:           /* 1 */
 981                return PERM_GROUP;
 982        case OLD_PERM_EVERYBODY:       /* 2 */
 983                return PERM_EVERYBODY;
 984        }
 985
 986        /* A filemode value was given: 0xxx */
 987
 988        if ((i & 0600) != 0600)
 989                die(_("Problem with core.sharedRepository filemode value "
 990                    "(0%.3o).\nThe owner of files must always have "
 991                    "read and write permissions."), i);
 992
 993        /*
 994         * Mask filemode value. Others can not get write permission.
 995         * x flags for directories are handled separately.
 996         */
 997        return -(i & 0666);
 998}
 999
1000void check_repository_format(void)
1001{
1002        check_repository_format_gently(get_git_dir(), NULL);
1003        startup_info->have_repository = 1;
1004}
1005
1006/*
1007 * Returns the "prefix", a path to the current working directory
1008 * relative to the work tree root, or NULL, if the current working
1009 * directory is not a strict subdirectory of the work tree root. The
1010 * prefix always ends with a '/' character.
1011 */
1012const char *setup_git_directory(void)
1013{
1014        return setup_git_directory_gently(NULL);
1015}
1016
1017const char *resolve_gitdir(const char *suspect)
1018{
1019        if (is_git_directory(suspect))
1020                return suspect;
1021        return read_gitfile(suspect);
1022}
1023
1024/* if any standard file descriptor is missing open it to /dev/null */
1025void sanitize_stdfds(void)
1026{
1027        int fd = open("/dev/null", O_RDWR, 0);
1028        while (fd != -1 && fd < 2)
1029                fd = dup(fd);
1030        if (fd == -1)
1031                die_errno("open /dev/null or dup failed");
1032        if (fd > 2)
1033                close(fd);
1034}
1035
1036int daemonize(void)
1037{
1038#ifdef NO_POSIX_GOODIES
1039        errno = ENOSYS;
1040        return -1;
1041#else
1042        switch (fork()) {
1043                case 0:
1044                        break;
1045                case -1:
1046                        die_errno("fork failed");
1047                default:
1048                        exit(0);
1049        }
1050        if (setsid() == -1)
1051                die_errno("setsid failed");
1052        close(0);
1053        close(1);
1054        close(2);
1055        sanitize_stdfds();
1056        return 0;
1057#endif
1058}