setup.con commit sha1_file: refactor has_sha1_file_with_flags (e83e71c)
   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        char *to_free = NULL;
 139        struct stat st;
 140
 141        if (starts_with(arg, ":/")) {
 142                if (arg[2] == '\0') /* ":/" is root dir, always exists */
 143                        return 1;
 144                name = arg + 2;
 145        } else if (prefix)
 146                name = to_free = prefix_filename(prefix, arg);
 147        else
 148                name = arg;
 149        if (!lstat(name, &st)) {
 150                free(to_free);
 151                return 1; /* file exists */
 152        }
 153        if (is_missing_file_error(errno)) {
 154                free(to_free);
 155                return 0; /* file does not exist */
 156        }
 157        die_errno("failed to stat '%s'", arg);
 158}
 159
 160static void NORETURN die_verify_filename(const char *prefix,
 161                                         const char *arg,
 162                                         int diagnose_misspelt_rev)
 163{
 164        if (!diagnose_misspelt_rev)
 165                die(_("%s: no such path in the working tree.\n"
 166                      "Use 'git <command> -- <path>...' to specify paths that do not exist locally."),
 167                    arg);
 168        /*
 169         * Saying "'(icase)foo' does not exist in the index" when the
 170         * user gave us ":(icase)foo" is just stupid.  A magic pathspec
 171         * begins with a colon and is followed by a non-alnum; do not
 172         * let maybe_die_on_misspelt_object_name() even trigger.
 173         */
 174        if (!(arg[0] == ':' && !isalnum(arg[1])))
 175                maybe_die_on_misspelt_object_name(arg, prefix);
 176
 177        /* ... or fall back the most general message. */
 178        die(_("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
 179              "Use '--' to separate paths from revisions, like this:\n"
 180              "'git <command> [<revision>...] -- [<file>...]'"), arg);
 181
 182}
 183
 184/*
 185 * Verify a filename that we got as an argument for a pathspec
 186 * entry. Note that a filename that begins with "-" never verifies
 187 * as true, because even if such a filename were to exist, we want
 188 * it to be preceded by the "--" marker (or we want the user to
 189 * use a format like "./-filename")
 190 *
 191 * The "diagnose_misspelt_rev" is used to provide a user-friendly
 192 * diagnosis when dying upon finding that "name" is not a pathname.
 193 * If set to 1, the diagnosis will try to diagnose "name" as an
 194 * invalid object name (e.g. HEAD:foo). If set to 0, the diagnosis
 195 * will only complain about an inexisting file.
 196 *
 197 * This function is typically called to check that a "file or rev"
 198 * argument is unambiguous. In this case, the caller will want
 199 * diagnose_misspelt_rev == 1 when verifying the first non-rev
 200 * argument (which could have been a revision), and
 201 * diagnose_misspelt_rev == 0 for the next ones (because we already
 202 * saw a filename, there's not ambiguity anymore).
 203 */
 204void verify_filename(const char *prefix,
 205                     const char *arg,
 206                     int diagnose_misspelt_rev)
 207{
 208        if (*arg == '-')
 209                die("bad flag '%s' used after filename", arg);
 210        if (check_filename(prefix, arg) || !no_wildcard(arg))
 211                return;
 212        die_verify_filename(prefix, arg, diagnose_misspelt_rev);
 213}
 214
 215/*
 216 * Opposite of the above: the command line did not have -- marker
 217 * and we parsed the arg as a refname.  It should not be interpretable
 218 * as a filename.
 219 */
 220void verify_non_filename(const char *prefix, const char *arg)
 221{
 222        if (!is_inside_work_tree() || is_inside_git_dir())
 223                return;
 224        if (*arg == '-')
 225                return; /* flag */
 226        if (!check_filename(prefix, arg))
 227                return;
 228        die(_("ambiguous argument '%s': both revision and filename\n"
 229              "Use '--' to separate paths from revisions, like this:\n"
 230              "'git <command> [<revision>...] -- [<file>...]'"), arg);
 231}
 232
 233int get_common_dir(struct strbuf *sb, const char *gitdir)
 234{
 235        const char *git_env_common_dir = getenv(GIT_COMMON_DIR_ENVIRONMENT);
 236        if (git_env_common_dir) {
 237                strbuf_addstr(sb, git_env_common_dir);
 238                return 1;
 239        } else {
 240                return get_common_dir_noenv(sb, gitdir);
 241        }
 242}
 243
 244int get_common_dir_noenv(struct strbuf *sb, const char *gitdir)
 245{
 246        struct strbuf data = STRBUF_INIT;
 247        struct strbuf path = STRBUF_INIT;
 248        int ret = 0;
 249
 250        strbuf_addf(&path, "%s/commondir", gitdir);
 251        if (file_exists(path.buf)) {
 252                if (strbuf_read_file(&data, path.buf, 0) <= 0)
 253                        die_errno(_("failed to read %s"), path.buf);
 254                while (data.len && (data.buf[data.len - 1] == '\n' ||
 255                                    data.buf[data.len - 1] == '\r'))
 256                        data.len--;
 257                data.buf[data.len] = '\0';
 258                strbuf_reset(&path);
 259                if (!is_absolute_path(data.buf))
 260                        strbuf_addf(&path, "%s/", gitdir);
 261                strbuf_addbuf(&path, &data);
 262                strbuf_add_real_path(sb, path.buf);
 263                ret = 1;
 264        } else {
 265                strbuf_addstr(sb, gitdir);
 266        }
 267
 268        strbuf_release(&data);
 269        strbuf_release(&path);
 270        return ret;
 271}
 272
 273/*
 274 * Test if it looks like we're at a git directory.
 275 * We want to see:
 276 *
 277 *  - either an objects/ directory _or_ the proper
 278 *    GIT_OBJECT_DIRECTORY environment variable
 279 *  - a refs/ directory
 280 *  - either a HEAD symlink or a HEAD file that is formatted as
 281 *    a proper "ref:", or a regular file HEAD that has a properly
 282 *    formatted sha1 object name.
 283 */
 284int is_git_directory(const char *suspect)
 285{
 286        struct strbuf path = STRBUF_INIT;
 287        int ret = 0;
 288        size_t len;
 289
 290        /* Check worktree-related signatures */
 291        strbuf_addf(&path, "%s/HEAD", suspect);
 292        if (validate_headref(path.buf))
 293                goto done;
 294
 295        strbuf_reset(&path);
 296        get_common_dir(&path, suspect);
 297        len = path.len;
 298
 299        /* Check non-worktree-related signatures */
 300        if (getenv(DB_ENVIRONMENT)) {
 301                if (access(getenv(DB_ENVIRONMENT), X_OK))
 302                        goto done;
 303        }
 304        else {
 305                strbuf_setlen(&path, len);
 306                strbuf_addstr(&path, "/objects");
 307                if (access(path.buf, X_OK))
 308                        goto done;
 309        }
 310
 311        strbuf_setlen(&path, len);
 312        strbuf_addstr(&path, "/refs");
 313        if (access(path.buf, X_OK))
 314                goto done;
 315
 316        ret = 1;
 317done:
 318        strbuf_release(&path);
 319        return ret;
 320}
 321
 322int is_nonbare_repository_dir(struct strbuf *path)
 323{
 324        int ret = 0;
 325        int gitfile_error;
 326        size_t orig_path_len = path->len;
 327        assert(orig_path_len != 0);
 328        strbuf_complete(path, '/');
 329        strbuf_addstr(path, ".git");
 330        if (read_gitfile_gently(path->buf, &gitfile_error) || is_git_directory(path->buf))
 331                ret = 1;
 332        if (gitfile_error == READ_GITFILE_ERR_OPEN_FAILED ||
 333            gitfile_error == READ_GITFILE_ERR_READ_FAILED)
 334                ret = 1;
 335        strbuf_setlen(path, orig_path_len);
 336        return ret;
 337}
 338
 339int is_inside_git_dir(void)
 340{
 341        if (inside_git_dir < 0)
 342                inside_git_dir = is_inside_dir(get_git_dir());
 343        return inside_git_dir;
 344}
 345
 346int is_inside_work_tree(void)
 347{
 348        if (inside_work_tree < 0)
 349                inside_work_tree = is_inside_dir(get_git_work_tree());
 350        return inside_work_tree;
 351}
 352
 353void setup_work_tree(void)
 354{
 355        const char *work_tree, *git_dir;
 356        static int initialized = 0;
 357
 358        if (initialized)
 359                return;
 360
 361        if (work_tree_config_is_bogus)
 362                die("unable to set up work tree using invalid config");
 363
 364        work_tree = get_git_work_tree();
 365        git_dir = get_git_dir();
 366        if (!is_absolute_path(git_dir))
 367                git_dir = real_path(get_git_dir());
 368        if (!work_tree || chdir(work_tree))
 369                die("This operation must be run in a work tree");
 370
 371        /*
 372         * Make sure subsequent git processes find correct worktree
 373         * if $GIT_WORK_TREE is set relative
 374         */
 375        if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 376                setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 377
 378        set_git_dir(remove_leading_path(git_dir, work_tree));
 379        initialized = 1;
 380}
 381
 382static int check_repo_format(const char *var, const char *value, void *vdata)
 383{
 384        struct repository_format *data = vdata;
 385        const char *ext;
 386
 387        if (strcmp(var, "core.repositoryformatversion") == 0)
 388                data->version = git_config_int(var, value);
 389        else if (skip_prefix(var, "extensions.", &ext)) {
 390                /*
 391                 * record any known extensions here; otherwise,
 392                 * we fall through to recording it as unknown, and
 393                 * check_repository_format will complain
 394                 */
 395                if (!strcmp(ext, "noop"))
 396                        ;
 397                else if (!strcmp(ext, "preciousobjects"))
 398                        data->precious_objects = git_config_bool(var, value);
 399                else
 400                        string_list_append(&data->unknown_extensions, ext);
 401        } else if (strcmp(var, "core.bare") == 0) {
 402                data->is_bare = git_config_bool(var, value);
 403        } else if (strcmp(var, "core.worktree") == 0) {
 404                if (!value)
 405                        return config_error_nonbool(var);
 406                data->work_tree = xstrdup(value);
 407        }
 408        return 0;
 409}
 410
 411static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 412{
 413        struct strbuf sb = STRBUF_INIT;
 414        struct strbuf err = STRBUF_INIT;
 415        struct repository_format candidate;
 416        int has_common;
 417
 418        has_common = get_common_dir(&sb, gitdir);
 419        strbuf_addstr(&sb, "/config");
 420        read_repository_format(&candidate, sb.buf);
 421        strbuf_release(&sb);
 422
 423        /*
 424         * For historical use of check_repository_format() in git-init,
 425         * we treat a missing config as a silent "ok", even when nongit_ok
 426         * is unset.
 427         */
 428        if (candidate.version < 0)
 429                return 0;
 430
 431        if (verify_repository_format(&candidate, &err) < 0) {
 432                if (nongit_ok) {
 433                        warning("%s", err.buf);
 434                        strbuf_release(&err);
 435                        *nongit_ok = -1;
 436                        return -1;
 437                }
 438                die("%s", err.buf);
 439        }
 440
 441        repository_format_precious_objects = candidate.precious_objects;
 442        string_list_clear(&candidate.unknown_extensions, 0);
 443        if (!has_common) {
 444                if (candidate.is_bare != -1) {
 445                        is_bare_repository_cfg = candidate.is_bare;
 446                        if (is_bare_repository_cfg == 1)
 447                                inside_work_tree = -1;
 448                }
 449                if (candidate.work_tree) {
 450                        free(git_work_tree_cfg);
 451                        git_work_tree_cfg = candidate.work_tree;
 452                        inside_work_tree = -1;
 453                }
 454        } else {
 455                free(candidate.work_tree);
 456        }
 457
 458        return 0;
 459}
 460
 461int read_repository_format(struct repository_format *format, const char *path)
 462{
 463        memset(format, 0, sizeof(*format));
 464        format->version = -1;
 465        format->is_bare = -1;
 466        string_list_init(&format->unknown_extensions, 1);
 467        git_config_from_file(check_repo_format, path, format);
 468        return format->version;
 469}
 470
 471int verify_repository_format(const struct repository_format *format,
 472                             struct strbuf *err)
 473{
 474        if (GIT_REPO_VERSION_READ < format->version) {
 475                strbuf_addf(err, _("Expected git repo version <= %d, found %d"),
 476                            GIT_REPO_VERSION_READ, format->version);
 477                return -1;
 478        }
 479
 480        if (format->version >= 1 && format->unknown_extensions.nr) {
 481                int i;
 482
 483                strbuf_addstr(err, _("unknown repository extensions found:"));
 484
 485                for (i = 0; i < format->unknown_extensions.nr; i++)
 486                        strbuf_addf(err, "\n\t%s",
 487                                    format->unknown_extensions.items[i].string);
 488                return -1;
 489        }
 490
 491        return 0;
 492}
 493
 494void read_gitfile_error_die(int error_code, const char *path, const char *dir)
 495{
 496        switch (error_code) {
 497        case READ_GITFILE_ERR_STAT_FAILED:
 498        case READ_GITFILE_ERR_NOT_A_FILE:
 499                /* non-fatal; follow return path */
 500                break;
 501        case READ_GITFILE_ERR_OPEN_FAILED:
 502                die_errno("Error opening '%s'", path);
 503        case READ_GITFILE_ERR_TOO_LARGE:
 504                die("Too large to be a .git file: '%s'", path);
 505        case READ_GITFILE_ERR_READ_FAILED:
 506                die("Error reading %s", path);
 507        case READ_GITFILE_ERR_INVALID_FORMAT:
 508                die("Invalid gitfile format: %s", path);
 509        case READ_GITFILE_ERR_NO_PATH:
 510                die("No path in gitfile: %s", path);
 511        case READ_GITFILE_ERR_NOT_A_REPO:
 512                die("Not a git repository: %s", dir);
 513        default:
 514                die("BUG: unknown error code");
 515        }
 516}
 517
 518/*
 519 * Try to read the location of the git directory from the .git file,
 520 * return path to git directory if found.
 521 *
 522 * On failure, if return_error_code is not NULL, return_error_code
 523 * will be set to an error code and NULL will be returned. If
 524 * return_error_code is NULL the function will die instead (for most
 525 * cases).
 526 */
 527const char *read_gitfile_gently(const char *path, int *return_error_code)
 528{
 529        const int max_file_size = 1 << 20;  /* 1MB */
 530        int error_code = 0;
 531        char *buf = NULL;
 532        char *dir = NULL;
 533        const char *slash;
 534        struct stat st;
 535        int fd;
 536        ssize_t len;
 537
 538        if (stat(path, &st)) {
 539                /* NEEDSWORK: discern between ENOENT vs other errors */
 540                error_code = READ_GITFILE_ERR_STAT_FAILED;
 541                goto cleanup_return;
 542        }
 543        if (!S_ISREG(st.st_mode)) {
 544                error_code = READ_GITFILE_ERR_NOT_A_FILE;
 545                goto cleanup_return;
 546        }
 547        if (st.st_size > max_file_size) {
 548                error_code = READ_GITFILE_ERR_TOO_LARGE;
 549                goto cleanup_return;
 550        }
 551        fd = open(path, O_RDONLY);
 552        if (fd < 0) {
 553                error_code = READ_GITFILE_ERR_OPEN_FAILED;
 554                goto cleanup_return;
 555        }
 556        buf = xmallocz(st.st_size);
 557        len = read_in_full(fd, buf, st.st_size);
 558        close(fd);
 559        if (len != st.st_size) {
 560                error_code = READ_GITFILE_ERR_READ_FAILED;
 561                goto cleanup_return;
 562        }
 563        if (!starts_with(buf, "gitdir: ")) {
 564                error_code = READ_GITFILE_ERR_INVALID_FORMAT;
 565                goto cleanup_return;
 566        }
 567        while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 568                len--;
 569        if (len < 9) {
 570                error_code = READ_GITFILE_ERR_NO_PATH;
 571                goto cleanup_return;
 572        }
 573        buf[len] = '\0';
 574        dir = buf + 8;
 575
 576        if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
 577                size_t pathlen = slash+1 - path;
 578                dir = xstrfmt("%.*s%.*s", (int)pathlen, path,
 579                              (int)(len - 8), buf + 8);
 580                free(buf);
 581                buf = dir;
 582        }
 583        if (!is_git_directory(dir)) {
 584                error_code = READ_GITFILE_ERR_NOT_A_REPO;
 585                goto cleanup_return;
 586        }
 587        path = real_path(dir);
 588
 589cleanup_return:
 590        if (return_error_code)
 591                *return_error_code = error_code;
 592        else if (error_code)
 593                read_gitfile_error_die(error_code, path, dir);
 594
 595        free(buf);
 596        return error_code ? NULL : path;
 597}
 598
 599static const char *setup_explicit_git_dir(const char *gitdirenv,
 600                                          struct strbuf *cwd,
 601                                          int *nongit_ok)
 602{
 603        const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 604        const char *worktree;
 605        char *gitfile;
 606        int offset;
 607
 608        if (PATH_MAX - 40 < strlen(gitdirenv))
 609                die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 610
 611        gitfile = (char*)read_gitfile(gitdirenv);
 612        if (gitfile) {
 613                gitfile = xstrdup(gitfile);
 614                gitdirenv = gitfile;
 615        }
 616
 617        if (!is_git_directory(gitdirenv)) {
 618                if (nongit_ok) {
 619                        *nongit_ok = 1;
 620                        free(gitfile);
 621                        return NULL;
 622                }
 623                die("Not a git repository: '%s'", gitdirenv);
 624        }
 625
 626        if (check_repository_format_gently(gitdirenv, nongit_ok)) {
 627                free(gitfile);
 628                return NULL;
 629        }
 630
 631        /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
 632        if (work_tree_env)
 633                set_git_work_tree(work_tree_env);
 634        else if (is_bare_repository_cfg > 0) {
 635                if (git_work_tree_cfg) {
 636                        /* #22.2, #30 */
 637                        warning("core.bare and core.worktree do not make sense");
 638                        work_tree_config_is_bogus = 1;
 639                }
 640
 641                /* #18, #26 */
 642                set_git_dir(gitdirenv);
 643                free(gitfile);
 644                return NULL;
 645        }
 646        else if (git_work_tree_cfg) { /* #6, #14 */
 647                if (is_absolute_path(git_work_tree_cfg))
 648                        set_git_work_tree(git_work_tree_cfg);
 649                else {
 650                        char *core_worktree;
 651                        if (chdir(gitdirenv))
 652                                die_errno("Could not chdir to '%s'", gitdirenv);
 653                        if (chdir(git_work_tree_cfg))
 654                                die_errno("Could not chdir to '%s'", git_work_tree_cfg);
 655                        core_worktree = xgetcwd();
 656                        if (chdir(cwd->buf))
 657                                die_errno("Could not come back to cwd");
 658                        set_git_work_tree(core_worktree);
 659                        free(core_worktree);
 660                }
 661        }
 662        else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
 663                /* #16d */
 664                set_git_dir(gitdirenv);
 665                free(gitfile);
 666                return NULL;
 667        }
 668        else /* #2, #10 */
 669                set_git_work_tree(".");
 670
 671        /* set_git_work_tree() must have been called by now */
 672        worktree = get_git_work_tree();
 673
 674        /* both get_git_work_tree() and cwd are already normalized */
 675        if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */
 676                set_git_dir(gitdirenv);
 677                free(gitfile);
 678                return NULL;
 679        }
 680
 681        offset = dir_inside_of(cwd->buf, worktree);
 682        if (offset >= 0) {      /* cwd inside worktree? */
 683                set_git_dir(real_path(gitdirenv));
 684                if (chdir(worktree))
 685                        die_errno("Could not chdir to '%s'", worktree);
 686                strbuf_addch(cwd, '/');
 687                free(gitfile);
 688                return cwd->buf + offset;
 689        }
 690
 691        /* cwd outside worktree */
 692        set_git_dir(gitdirenv);
 693        free(gitfile);
 694        return NULL;
 695}
 696
 697static const char *setup_discovered_git_dir(const char *gitdir,
 698                                            struct strbuf *cwd, int offset,
 699                                            int *nongit_ok)
 700{
 701        if (check_repository_format_gently(gitdir, nongit_ok))
 702                return NULL;
 703
 704        /* --work-tree is set without --git-dir; use discovered one */
 705        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 706                char *to_free = NULL;
 707                const char *ret;
 708
 709                if (offset != cwd->len && !is_absolute_path(gitdir))
 710                        gitdir = to_free = real_pathdup(gitdir, 1);
 711                if (chdir(cwd->buf))
 712                        die_errno("Could not come back to cwd");
 713                ret = setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 714                free(to_free);
 715                return ret;
 716        }
 717
 718        /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 719        if (is_bare_repository_cfg > 0) {
 720                set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir));
 721                if (chdir(cwd->buf))
 722                        die_errno("Could not come back to cwd");
 723                return NULL;
 724        }
 725
 726        /* #0, #1, #5, #8, #9, #12, #13 */
 727        set_git_work_tree(".");
 728        if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
 729                set_git_dir(gitdir);
 730        inside_git_dir = 0;
 731        inside_work_tree = 1;
 732        if (offset == cwd->len)
 733                return NULL;
 734
 735        /* Make "offset" point past the '/' (already the case for root dirs) */
 736        if (offset != offset_1st_component(cwd->buf))
 737                offset++;
 738        /* Add a '/' at the end */
 739        strbuf_addch(cwd, '/');
 740        return cwd->buf + offset;
 741}
 742
 743/* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
 744static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
 745                                      int *nongit_ok)
 746{
 747        int root_len;
 748
 749        if (check_repository_format_gently(".", nongit_ok))
 750                return NULL;
 751
 752        setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 753
 754        /* --work-tree is set without --git-dir; use discovered one */
 755        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 756                static const char *gitdir;
 757
 758                gitdir = offset == cwd->len ? "." : xmemdupz(cwd->buf, offset);
 759                if (chdir(cwd->buf))
 760                        die_errno("Could not come back to cwd");
 761                return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 762        }
 763
 764        inside_git_dir = 1;
 765        inside_work_tree = 0;
 766        if (offset != cwd->len) {
 767                if (chdir(cwd->buf))
 768                        die_errno("Cannot come back to cwd");
 769                root_len = offset_1st_component(cwd->buf);
 770                strbuf_setlen(cwd, offset > root_len ? offset : root_len);
 771                set_git_dir(cwd->buf);
 772        }
 773        else
 774                set_git_dir(".");
 775        return NULL;
 776}
 777
 778static const char *setup_nongit(const char *cwd, int *nongit_ok)
 779{
 780        if (!nongit_ok)
 781                die(_("Not a git repository (or any of the parent directories): %s"), DEFAULT_GIT_DIR_ENVIRONMENT);
 782        if (chdir(cwd))
 783                die_errno(_("Cannot come back to cwd"));
 784        *nongit_ok = 1;
 785        return NULL;
 786}
 787
 788static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
 789{
 790        struct stat buf;
 791        if (stat(path, &buf)) {
 792                die_errno("failed to stat '%*s%s%s'",
 793                                prefix_len,
 794                                prefix ? prefix : "",
 795                                prefix ? "/" : "", path);
 796        }
 797        return buf.st_dev;
 798}
 799
 800/*
 801 * A "string_list_each_func_t" function that canonicalizes an entry
 802 * from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or
 803 * discards it if unusable.  The presence of an empty entry in
 804 * GIT_CEILING_DIRECTORIES turns off canonicalization for all
 805 * subsequent entries.
 806 */
 807static int canonicalize_ceiling_entry(struct string_list_item *item,
 808                                      void *cb_data)
 809{
 810        int *empty_entry_found = cb_data;
 811        char *ceil = item->string;
 812
 813        if (!*ceil) {
 814                *empty_entry_found = 1;
 815                return 0;
 816        } else if (!is_absolute_path(ceil)) {
 817                return 0;
 818        } else if (*empty_entry_found) {
 819                /* Keep entry but do not canonicalize it */
 820                return 1;
 821        } else {
 822                char *real_path = real_pathdup(ceil, 0);
 823                if (!real_path) {
 824                        return 0;
 825                }
 826                free(item->string);
 827                item->string = real_path;
 828                return 1;
 829        }
 830}
 831
 832enum discovery_result {
 833        GIT_DIR_NONE = 0,
 834        GIT_DIR_EXPLICIT,
 835        GIT_DIR_DISCOVERED,
 836        GIT_DIR_BARE,
 837        /* these are errors */
 838        GIT_DIR_HIT_CEILING = -1,
 839        GIT_DIR_HIT_MOUNT_POINT = -2,
 840        GIT_DIR_INVALID_GITFILE = -3
 841};
 842
 843/*
 844 * We cannot decide in this function whether we are in the work tree or
 845 * not, since the config can only be read _after_ this function was called.
 846 *
 847 * Also, we avoid changing any global state (such as the current working
 848 * directory) to allow early callers.
 849 *
 850 * The directory where the search should start needs to be passed in via the
 851 * `dir` parameter; upon return, the `dir` buffer will contain the path of
 852 * the directory where the search ended, and `gitdir` will contain the path of
 853 * the discovered .git/ directory, if any. If `gitdir` is not absolute, it
 854 * is relative to `dir` (i.e. *not* necessarily the cwd).
 855 */
 856static enum discovery_result setup_git_directory_gently_1(struct strbuf *dir,
 857                                                          struct strbuf *gitdir,
 858                                                          int die_on_error)
 859{
 860        const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 861        struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
 862        const char *gitdirenv;
 863        int ceil_offset = -1, min_offset = has_dos_drive_prefix(dir->buf) ? 3 : 1;
 864        dev_t current_device = 0;
 865        int one_filesystem = 1;
 866
 867        /*
 868         * If GIT_DIR is set explicitly, we're not going
 869         * to do any discovery, but we still do repository
 870         * validation.
 871         */
 872        gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 873        if (gitdirenv) {
 874                strbuf_addstr(gitdir, gitdirenv);
 875                return GIT_DIR_EXPLICIT;
 876        }
 877
 878        if (env_ceiling_dirs) {
 879                int empty_entry_found = 0;
 880
 881                string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
 882                filter_string_list(&ceiling_dirs, 0,
 883                                   canonicalize_ceiling_entry, &empty_entry_found);
 884                ceil_offset = longest_ancestor_length(dir->buf, &ceiling_dirs);
 885                string_list_clear(&ceiling_dirs, 0);
 886        }
 887
 888        if (ceil_offset < 0)
 889                ceil_offset = min_offset - 2;
 890
 891        /*
 892         * Test in the following order (relative to the dir):
 893         * - .git (file containing "gitdir: <path>")
 894         * - .git/
 895         * - ./ (bare)
 896         * - ../.git
 897         * - ../.git/
 898         * - ../ (bare)
 899         * - ../../.git/
 900         *   etc.
 901         */
 902        one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
 903        if (one_filesystem)
 904                current_device = get_device_or_die(dir->buf, NULL, 0);
 905        for (;;) {
 906                int offset = dir->len, error_code = 0;
 907
 908                if (offset > min_offset)
 909                        strbuf_addch(dir, '/');
 910                strbuf_addstr(dir, DEFAULT_GIT_DIR_ENVIRONMENT);
 911                gitdirenv = read_gitfile_gently(dir->buf, die_on_error ?
 912                                                NULL : &error_code);
 913                if (!gitdirenv) {
 914                        if (die_on_error ||
 915                            error_code == READ_GITFILE_ERR_NOT_A_FILE) {
 916                                /* NEEDSWORK: fail if .git is not file nor dir */
 917                                if (is_git_directory(dir->buf))
 918                                        gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
 919                        } else if (error_code != READ_GITFILE_ERR_STAT_FAILED)
 920                                return GIT_DIR_INVALID_GITFILE;
 921                }
 922                strbuf_setlen(dir, offset);
 923                if (gitdirenv) {
 924                        strbuf_addstr(gitdir, gitdirenv);
 925                        return GIT_DIR_DISCOVERED;
 926                }
 927
 928                if (is_git_directory(dir->buf)) {
 929                        strbuf_addstr(gitdir, ".");
 930                        return GIT_DIR_BARE;
 931                }
 932
 933                if (offset <= min_offset)
 934                        return GIT_DIR_HIT_CEILING;
 935
 936                while (--offset > ceil_offset && !is_dir_sep(dir->buf[offset]))
 937                        ; /* continue */
 938                if (offset <= ceil_offset)
 939                        return GIT_DIR_HIT_CEILING;
 940
 941                strbuf_setlen(dir, offset > min_offset ?  offset : min_offset);
 942                if (one_filesystem &&
 943                    current_device != get_device_or_die(dir->buf, NULL, offset))
 944                        return GIT_DIR_HIT_MOUNT_POINT;
 945        }
 946}
 947
 948const char *discover_git_directory(struct strbuf *gitdir)
 949{
 950        struct strbuf dir = STRBUF_INIT, err = STRBUF_INIT;
 951        size_t gitdir_offset = gitdir->len, cwd_len;
 952        struct repository_format candidate;
 953
 954        if (strbuf_getcwd(&dir))
 955                return NULL;
 956
 957        cwd_len = dir.len;
 958        if (setup_git_directory_gently_1(&dir, gitdir, 0) <= 0) {
 959                strbuf_release(&dir);
 960                return NULL;
 961        }
 962
 963        /*
 964         * The returned gitdir is relative to dir, and if dir does not reflect
 965         * the current working directory, we simply make the gitdir absolute.
 966         */
 967        if (dir.len < cwd_len && !is_absolute_path(gitdir->buf + gitdir_offset)) {
 968                /* Avoid a trailing "/." */
 969                if (!strcmp(".", gitdir->buf + gitdir_offset))
 970                        strbuf_setlen(gitdir, gitdir_offset);
 971                else
 972                        strbuf_addch(&dir, '/');
 973                strbuf_insert(gitdir, gitdir_offset, dir.buf, dir.len);
 974        }
 975
 976        strbuf_reset(&dir);
 977        strbuf_addf(&dir, "%s/config", gitdir->buf + gitdir_offset);
 978        read_repository_format(&candidate, dir.buf);
 979        strbuf_release(&dir);
 980
 981        if (verify_repository_format(&candidate, &err) < 0) {
 982                warning("ignoring git dir '%s': %s",
 983                        gitdir->buf + gitdir_offset, err.buf);
 984                strbuf_release(&err);
 985                return NULL;
 986        }
 987
 988        return gitdir->buf + gitdir_offset;
 989}
 990
 991const char *setup_git_directory_gently(int *nongit_ok)
 992{
 993        static struct strbuf cwd = STRBUF_INIT;
 994        struct strbuf dir = STRBUF_INIT, gitdir = STRBUF_INIT;
 995        const char *prefix, *env_prefix;
 996
 997        /*
 998         * We may have read an incomplete configuration before
 999         * setting-up the git directory. If so, clear the cache so
1000         * that the next queries to the configuration reload complete
1001         * configuration (including the per-repo config file that we
1002         * ignored previously).
1003         */
1004        git_config_clear();
1005
1006        /*
1007         * Let's assume that we are in a git repository.
1008         * If it turns out later that we are somewhere else, the value will be
1009         * updated accordingly.
1010         */
1011        if (nongit_ok)
1012                *nongit_ok = 0;
1013
1014        if (strbuf_getcwd(&cwd))
1015                die_errno(_("Unable to read current working directory"));
1016        strbuf_addbuf(&dir, &cwd);
1017
1018        switch (setup_git_directory_gently_1(&dir, &gitdir, 1)) {
1019        case GIT_DIR_NONE:
1020                prefix = NULL;
1021                break;
1022        case GIT_DIR_EXPLICIT:
1023                prefix = setup_explicit_git_dir(gitdir.buf, &cwd, nongit_ok);
1024                break;
1025        case GIT_DIR_DISCOVERED:
1026                if (dir.len < cwd.len && chdir(dir.buf))
1027                        die(_("Cannot change to '%s'"), dir.buf);
1028                prefix = setup_discovered_git_dir(gitdir.buf, &cwd, dir.len,
1029                                                  nongit_ok);
1030                break;
1031        case GIT_DIR_BARE:
1032                if (dir.len < cwd.len && chdir(dir.buf))
1033                        die(_("Cannot change to '%s'"), dir.buf);
1034                prefix = setup_bare_git_dir(&cwd, dir.len, nongit_ok);
1035                break;
1036        case GIT_DIR_HIT_CEILING:
1037                prefix = setup_nongit(cwd.buf, nongit_ok);
1038                break;
1039        case GIT_DIR_HIT_MOUNT_POINT:
1040                if (nongit_ok) {
1041                        *nongit_ok = 1;
1042                        strbuf_release(&cwd);
1043                        strbuf_release(&dir);
1044                        return NULL;
1045                }
1046                die(_("Not a git repository (or any parent up to mount point %s)\n"
1047                      "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set)."),
1048                    dir.buf);
1049        default:
1050                die("BUG: unhandled setup_git_directory_1() result");
1051        }
1052
1053        env_prefix = getenv(GIT_TOPLEVEL_PREFIX_ENVIRONMENT);
1054        if (env_prefix)
1055                prefix = env_prefix;
1056
1057        if (prefix)
1058                setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
1059        else
1060                setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
1061
1062        startup_info->have_repository = !nongit_ok || !*nongit_ok;
1063        startup_info->prefix = prefix;
1064
1065        strbuf_release(&dir);
1066        strbuf_release(&gitdir);
1067
1068        return prefix;
1069}
1070
1071int git_config_perm(const char *var, const char *value)
1072{
1073        int i;
1074        char *endptr;
1075
1076        if (value == NULL)
1077                return PERM_GROUP;
1078
1079        if (!strcmp(value, "umask"))
1080                return PERM_UMASK;
1081        if (!strcmp(value, "group"))
1082                return PERM_GROUP;
1083        if (!strcmp(value, "all") ||
1084            !strcmp(value, "world") ||
1085            !strcmp(value, "everybody"))
1086                return PERM_EVERYBODY;
1087
1088        /* Parse octal numbers */
1089        i = strtol(value, &endptr, 8);
1090
1091        /* If not an octal number, maybe true/false? */
1092        if (*endptr != 0)
1093                return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
1094
1095        /*
1096         * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
1097         * a chmod value to restrict to.
1098         */
1099        switch (i) {
1100        case PERM_UMASK:               /* 0 */
1101                return PERM_UMASK;
1102        case OLD_PERM_GROUP:           /* 1 */
1103                return PERM_GROUP;
1104        case OLD_PERM_EVERYBODY:       /* 2 */
1105                return PERM_EVERYBODY;
1106        }
1107
1108        /* A filemode value was given: 0xxx */
1109
1110        if ((i & 0600) != 0600)
1111                die(_("Problem with core.sharedRepository filemode value "
1112                    "(0%.3o).\nThe owner of files must always have "
1113                    "read and write permissions."), i);
1114
1115        /*
1116         * Mask filemode value. Others can not get write permission.
1117         * x flags for directories are handled separately.
1118         */
1119        return -(i & 0666);
1120}
1121
1122void check_repository_format(void)
1123{
1124        check_repository_format_gently(get_git_dir(), NULL);
1125        startup_info->have_repository = 1;
1126}
1127
1128/*
1129 * Returns the "prefix", a path to the current working directory
1130 * relative to the work tree root, or NULL, if the current working
1131 * directory is not a strict subdirectory of the work tree root. The
1132 * prefix always ends with a '/' character.
1133 */
1134const char *setup_git_directory(void)
1135{
1136        return setup_git_directory_gently(NULL);
1137}
1138
1139const char *resolve_gitdir_gently(const char *suspect, int *return_error_code)
1140{
1141        if (is_git_directory(suspect))
1142                return suspect;
1143        return read_gitfile_gently(suspect, return_error_code);
1144}
1145
1146/* if any standard file descriptor is missing open it to /dev/null */
1147void sanitize_stdfds(void)
1148{
1149        int fd = open("/dev/null", O_RDWR, 0);
1150        while (fd != -1 && fd < 2)
1151                fd = dup(fd);
1152        if (fd == -1)
1153                die_errno("open /dev/null or dup failed");
1154        if (fd > 2)
1155                close(fd);
1156}
1157
1158int daemonize(void)
1159{
1160#ifdef NO_POSIX_GOODIES
1161        errno = ENOSYS;
1162        return -1;
1163#else
1164        switch (fork()) {
1165                case 0:
1166                        break;
1167                case -1:
1168                        die_errno("fork failed");
1169                default:
1170                        exit(0);
1171        }
1172        if (setsid() == -1)
1173                die_errno("setsid failed");
1174        close(0);
1175        close(1);
1176        close(2);
1177        sanitize_stdfds();
1178        return 0;
1179#endif
1180}