setup.con commit Fourth batch (bc12974)
   1#include "cache.h"
   2#include "repository.h"
   3#include "config.h"
   4#include "dir.h"
   5#include "string-list.h"
   6#include "chdir-notify.h"
   7#include "promisor-remote.h"
   8
   9static int inside_git_dir = -1;
  10static int inside_work_tree = -1;
  11static int work_tree_config_is_bogus;
  12
  13static struct startup_info the_startup_info;
  14struct startup_info *startup_info = &the_startup_info;
  15
  16/*
  17 * The input parameter must contain an absolute path, and it must already be
  18 * normalized.
  19 *
  20 * Find the part of an absolute path that lies inside the work tree by
  21 * dereferencing symlinks outside the work tree, for example:
  22 * /dir1/repo/dir2/file   (work tree is /dir1/repo)      -> dir2/file
  23 * /dir/file              (work tree is /)               -> dir/file
  24 * /dir/symlink1/symlink2 (symlink1 points to work tree) -> symlink2
  25 * /dir/repolink/file     (repolink points to /dir/repo) -> file
  26 * /dir/repo              (exactly equal to work tree)   -> (empty string)
  27 */
  28static int abspath_part_inside_repo(char *path)
  29{
  30        size_t len;
  31        size_t wtlen;
  32        char *path0;
  33        int off;
  34        const char *work_tree = get_git_work_tree();
  35
  36        if (!work_tree)
  37                return -1;
  38        wtlen = strlen(work_tree);
  39        len = strlen(path);
  40        off = offset_1st_component(path);
  41
  42        /* check if work tree is already the prefix */
  43        if (wtlen <= len && !fspathncmp(path, work_tree, wtlen)) {
  44                if (path[wtlen] == '/') {
  45                        memmove(path, path + wtlen + 1, len - wtlen);
  46                        return 0;
  47                } else if (path[wtlen - 1] == '/' || path[wtlen] == '\0') {
  48                        /* work tree is the root, or the whole path */
  49                        memmove(path, path + wtlen, len - wtlen + 1);
  50                        return 0;
  51                }
  52                /* work tree might match beginning of a symlink to work tree */
  53                off = wtlen;
  54        }
  55        path0 = path;
  56        path += off;
  57
  58        /* check each '/'-terminated level */
  59        while (*path) {
  60                path++;
  61                if (*path == '/') {
  62                        *path = '\0';
  63                        if (fspathcmp(real_path(path0), work_tree) == 0) {
  64                                memmove(path0, path + 1, len - (path - path0));
  65                                return 0;
  66                        }
  67                        *path = '/';
  68                }
  69        }
  70
  71        /* check whole path */
  72        if (fspathcmp(real_path(path0), work_tree) == 0) {
  73                *path0 = '\0';
  74                return 0;
  75        }
  76
  77        return -1;
  78}
  79
  80/*
  81 * Normalize "path", prepending the "prefix" for relative paths. If
  82 * remaining_prefix is not NULL, return the actual prefix still
  83 * remains in the path. For example, prefix = sub1/sub2/ and path is
  84 *
  85 *  foo          -> sub1/sub2/foo  (full prefix)
  86 *  ../foo       -> sub1/foo       (remaining prefix is sub1/)
  87 *  ../../bar    -> bar            (no remaining prefix)
  88 *  ../../sub1/sub2/foo -> sub1/sub2/foo (but no remaining prefix)
  89 *  `pwd`/../bar -> sub1/bar       (no remaining prefix)
  90 */
  91char *prefix_path_gently(const char *prefix, int len,
  92                         int *remaining_prefix, const char *path)
  93{
  94        const char *orig = path;
  95        char *sanitized;
  96        if (is_absolute_path(orig)) {
  97                sanitized = xmallocz(strlen(path));
  98                if (remaining_prefix)
  99                        *remaining_prefix = 0;
 100                if (normalize_path_copy_len(sanitized, path, remaining_prefix)) {
 101                        free(sanitized);
 102                        return NULL;
 103                }
 104                if (abspath_part_inside_repo(sanitized)) {
 105                        free(sanitized);
 106                        return NULL;
 107                }
 108        } else {
 109                sanitized = xstrfmt("%.*s%s", len, len ? prefix : "", path);
 110                if (remaining_prefix)
 111                        *remaining_prefix = len;
 112                if (normalize_path_copy_len(sanitized, sanitized, remaining_prefix)) {
 113                        free(sanitized);
 114                        return NULL;
 115                }
 116        }
 117        return sanitized;
 118}
 119
 120char *prefix_path(const char *prefix, int len, const char *path)
 121{
 122        char *r = prefix_path_gently(prefix, len, NULL, path);
 123        if (!r)
 124                die(_("'%s' is outside repository"), path);
 125        return r;
 126}
 127
 128int path_inside_repo(const char *prefix, const char *path)
 129{
 130        int len = prefix ? strlen(prefix) : 0;
 131        char *r = prefix_path_gently(prefix, len, NULL, path);
 132        if (r) {
 133                free(r);
 134                return 1;
 135        }
 136        return 0;
 137}
 138
 139int check_filename(const char *prefix, const char *arg)
 140{
 141        char *to_free = NULL;
 142        struct stat st;
 143
 144        if (skip_prefix(arg, ":/", &arg)) {
 145                if (!*arg) /* ":/" is root dir, always exists */
 146                        return 1;
 147                prefix = NULL;
 148        } else if (skip_prefix(arg, ":!", &arg) ||
 149                   skip_prefix(arg, ":^", &arg)) {
 150                if (!*arg) /* excluding everything is silly, but allowed */
 151                        return 1;
 152        }
 153
 154        if (prefix)
 155                arg = to_free = prefix_filename(prefix, arg);
 156
 157        if (!lstat(arg, &st)) {
 158                free(to_free);
 159                return 1; /* file exists */
 160        }
 161        if (is_missing_file_error(errno)) {
 162                free(to_free);
 163                return 0; /* file does not exist */
 164        }
 165        die_errno(_("failed to stat '%s'"), arg);
 166}
 167
 168static void NORETURN die_verify_filename(struct repository *r,
 169                                         const char *prefix,
 170                                         const char *arg,
 171                                         int diagnose_misspelt_rev)
 172{
 173        if (!diagnose_misspelt_rev)
 174                die(_("%s: no such path in the working tree.\n"
 175                      "Use 'git <command> -- <path>...' to specify paths that do not exist locally."),
 176                    arg);
 177        /*
 178         * Saying "'(icase)foo' does not exist in the index" when the
 179         * user gave us ":(icase)foo" is just stupid.  A magic pathspec
 180         * begins with a colon and is followed by a non-alnum; do not
 181         * let maybe_die_on_misspelt_object_name() even trigger.
 182         */
 183        if (!(arg[0] == ':' && !isalnum(arg[1])))
 184                maybe_die_on_misspelt_object_name(r, arg, prefix);
 185
 186        /* ... or fall back the most general message. */
 187        die(_("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
 188              "Use '--' to separate paths from revisions, like this:\n"
 189              "'git <command> [<revision>...] -- [<file>...]'"), arg);
 190
 191}
 192
 193/*
 194 * Check for arguments that don't resolve as actual files,
 195 * but which look sufficiently like pathspecs that we'll consider
 196 * them such for the purposes of rev/pathspec DWIM parsing.
 197 */
 198static int looks_like_pathspec(const char *arg)
 199{
 200        /* anything with a wildcard character */
 201        if (!no_wildcard(arg))
 202                return 1;
 203
 204        /* long-form pathspec magic */
 205        if (starts_with(arg, ":("))
 206                return 1;
 207
 208        return 0;
 209}
 210
 211/*
 212 * Verify a filename that we got as an argument for a pathspec
 213 * entry. Note that a filename that begins with "-" never verifies
 214 * as true, because even if such a filename were to exist, we want
 215 * it to be preceded by the "--" marker (or we want the user to
 216 * use a format like "./-filename")
 217 *
 218 * The "diagnose_misspelt_rev" is used to provide a user-friendly
 219 * diagnosis when dying upon finding that "name" is not a pathname.
 220 * If set to 1, the diagnosis will try to diagnose "name" as an
 221 * invalid object name (e.g. HEAD:foo). If set to 0, the diagnosis
 222 * will only complain about an inexisting file.
 223 *
 224 * This function is typically called to check that a "file or rev"
 225 * argument is unambiguous. In this case, the caller will want
 226 * diagnose_misspelt_rev == 1 when verifying the first non-rev
 227 * argument (which could have been a revision), and
 228 * diagnose_misspelt_rev == 0 for the next ones (because we already
 229 * saw a filename, there's not ambiguity anymore).
 230 */
 231void verify_filename(const char *prefix,
 232                     const char *arg,
 233                     int diagnose_misspelt_rev)
 234{
 235        if (*arg == '-')
 236                die(_("option '%s' must come before non-option arguments"), arg);
 237        if (looks_like_pathspec(arg) || check_filename(prefix, arg))
 238                return;
 239        die_verify_filename(the_repository, prefix, arg, diagnose_misspelt_rev);
 240}
 241
 242/*
 243 * Opposite of the above: the command line did not have -- marker
 244 * and we parsed the arg as a refname.  It should not be interpretable
 245 * as a filename.
 246 */
 247void verify_non_filename(const char *prefix, const char *arg)
 248{
 249        if (!is_inside_work_tree() || is_inside_git_dir())
 250                return;
 251        if (*arg == '-')
 252                return; /* flag */
 253        if (!check_filename(prefix, arg))
 254                return;
 255        die(_("ambiguous argument '%s': both revision and filename\n"
 256              "Use '--' to separate paths from revisions, like this:\n"
 257              "'git <command> [<revision>...] -- [<file>...]'"), arg);
 258}
 259
 260int get_common_dir(struct strbuf *sb, const char *gitdir)
 261{
 262        const char *git_env_common_dir = getenv(GIT_COMMON_DIR_ENVIRONMENT);
 263        if (git_env_common_dir) {
 264                strbuf_addstr(sb, git_env_common_dir);
 265                return 1;
 266        } else {
 267                return get_common_dir_noenv(sb, gitdir);
 268        }
 269}
 270
 271int get_common_dir_noenv(struct strbuf *sb, const char *gitdir)
 272{
 273        struct strbuf data = STRBUF_INIT;
 274        struct strbuf path = STRBUF_INIT;
 275        int ret = 0;
 276
 277        strbuf_addf(&path, "%s/commondir", gitdir);
 278        if (file_exists(path.buf)) {
 279                if (strbuf_read_file(&data, path.buf, 0) <= 0)
 280                        die_errno(_("failed to read %s"), path.buf);
 281                while (data.len && (data.buf[data.len - 1] == '\n' ||
 282                                    data.buf[data.len - 1] == '\r'))
 283                        data.len--;
 284                data.buf[data.len] = '\0';
 285                strbuf_reset(&path);
 286                if (!is_absolute_path(data.buf))
 287                        strbuf_addf(&path, "%s/", gitdir);
 288                strbuf_addbuf(&path, &data);
 289                strbuf_add_real_path(sb, path.buf);
 290                ret = 1;
 291        } else {
 292                strbuf_addstr(sb, gitdir);
 293        }
 294
 295        strbuf_release(&data);
 296        strbuf_release(&path);
 297        return ret;
 298}
 299
 300/*
 301 * Test if it looks like we're at a git directory.
 302 * We want to see:
 303 *
 304 *  - either an objects/ directory _or_ the proper
 305 *    GIT_OBJECT_DIRECTORY environment variable
 306 *  - a refs/ directory
 307 *  - either a HEAD symlink or a HEAD file that is formatted as
 308 *    a proper "ref:", or a regular file HEAD that has a properly
 309 *    formatted sha1 object name.
 310 */
 311int is_git_directory(const char *suspect)
 312{
 313        struct strbuf path = STRBUF_INIT;
 314        int ret = 0;
 315        size_t len;
 316
 317        /* Check worktree-related signatures */
 318        strbuf_addstr(&path, suspect);
 319        strbuf_complete(&path, '/');
 320        strbuf_addstr(&path, "HEAD");
 321        if (validate_headref(path.buf))
 322                goto done;
 323
 324        strbuf_reset(&path);
 325        get_common_dir(&path, suspect);
 326        len = path.len;
 327
 328        /* Check non-worktree-related signatures */
 329        if (getenv(DB_ENVIRONMENT)) {
 330                if (access(getenv(DB_ENVIRONMENT), X_OK))
 331                        goto done;
 332        }
 333        else {
 334                strbuf_setlen(&path, len);
 335                strbuf_addstr(&path, "/objects");
 336                if (access(path.buf, X_OK))
 337                        goto done;
 338        }
 339
 340        strbuf_setlen(&path, len);
 341        strbuf_addstr(&path, "/refs");
 342        if (access(path.buf, X_OK))
 343                goto done;
 344
 345        ret = 1;
 346done:
 347        strbuf_release(&path);
 348        return ret;
 349}
 350
 351int is_nonbare_repository_dir(struct strbuf *path)
 352{
 353        int ret = 0;
 354        int gitfile_error;
 355        size_t orig_path_len = path->len;
 356        assert(orig_path_len != 0);
 357        strbuf_complete(path, '/');
 358        strbuf_addstr(path, ".git");
 359        if (read_gitfile_gently(path->buf, &gitfile_error) || is_git_directory(path->buf))
 360                ret = 1;
 361        if (gitfile_error == READ_GITFILE_ERR_OPEN_FAILED ||
 362            gitfile_error == READ_GITFILE_ERR_READ_FAILED)
 363                ret = 1;
 364        strbuf_setlen(path, orig_path_len);
 365        return ret;
 366}
 367
 368int is_inside_git_dir(void)
 369{
 370        if (inside_git_dir < 0)
 371                inside_git_dir = is_inside_dir(get_git_dir());
 372        return inside_git_dir;
 373}
 374
 375int is_inside_work_tree(void)
 376{
 377        if (inside_work_tree < 0)
 378                inside_work_tree = is_inside_dir(get_git_work_tree());
 379        return inside_work_tree;
 380}
 381
 382void setup_work_tree(void)
 383{
 384        const char *work_tree;
 385        static int initialized = 0;
 386
 387        if (initialized)
 388                return;
 389
 390        if (work_tree_config_is_bogus)
 391                die(_("unable to set up work tree using invalid config"));
 392
 393        work_tree = get_git_work_tree();
 394        if (!work_tree || chdir_notify(work_tree))
 395                die(_("this operation must be run in a work tree"));
 396
 397        /*
 398         * Make sure subsequent git processes find correct worktree
 399         * if $GIT_WORK_TREE is set relative
 400         */
 401        if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 402                setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 403
 404        initialized = 1;
 405}
 406
 407static int read_worktree_config(const char *var, const char *value, void *vdata)
 408{
 409        struct repository_format *data = vdata;
 410
 411        if (strcmp(var, "core.bare") == 0) {
 412                data->is_bare = git_config_bool(var, value);
 413        } else if (strcmp(var, "core.worktree") == 0) {
 414                if (!value)
 415                        return config_error_nonbool(var);
 416                free(data->work_tree);
 417                data->work_tree = xstrdup(value);
 418        }
 419        return 0;
 420}
 421
 422static int check_repo_format(const char *var, const char *value, void *vdata)
 423{
 424        struct repository_format *data = vdata;
 425        const char *ext;
 426
 427        if (strcmp(var, "core.repositoryformatversion") == 0)
 428                data->version = git_config_int(var, value);
 429        else if (skip_prefix(var, "extensions.", &ext)) {
 430                /*
 431                 * record any known extensions here; otherwise,
 432                 * we fall through to recording it as unknown, and
 433                 * check_repository_format will complain
 434                 */
 435                if (!strcmp(ext, "noop"))
 436                        ;
 437                else if (!strcmp(ext, "preciousobjects"))
 438                        data->precious_objects = git_config_bool(var, value);
 439                else if (!strcmp(ext, "partialclone")) {
 440                        if (!value)
 441                                return config_error_nonbool(var);
 442                        data->partial_clone = xstrdup(value);
 443                } else if (!strcmp(ext, "worktreeconfig"))
 444                        data->worktree_config = git_config_bool(var, value);
 445                else
 446                        string_list_append(&data->unknown_extensions, ext);
 447        }
 448
 449        return read_worktree_config(var, value, vdata);
 450}
 451
 452static int check_repository_format_gently(const char *gitdir, struct repository_format *candidate, int *nongit_ok)
 453{
 454        struct strbuf sb = STRBUF_INIT;
 455        struct strbuf err = STRBUF_INIT;
 456        int has_common;
 457
 458        has_common = get_common_dir(&sb, gitdir);
 459        strbuf_addstr(&sb, "/config");
 460        read_repository_format(candidate, sb.buf);
 461        strbuf_release(&sb);
 462
 463        /*
 464         * For historical use of check_repository_format() in git-init,
 465         * we treat a missing config as a silent "ok", even when nongit_ok
 466         * is unset.
 467         */
 468        if (candidate->version < 0)
 469                return 0;
 470
 471        if (verify_repository_format(candidate, &err) < 0) {
 472                if (nongit_ok) {
 473                        warning("%s", err.buf);
 474                        strbuf_release(&err);
 475                        *nongit_ok = -1;
 476                        return -1;
 477                }
 478                die("%s", err.buf);
 479        }
 480
 481        repository_format_precious_objects = candidate->precious_objects;
 482        set_repository_format_partial_clone(candidate->partial_clone);
 483        repository_format_worktree_config = candidate->worktree_config;
 484        string_list_clear(&candidate->unknown_extensions, 0);
 485
 486        if (repository_format_worktree_config) {
 487                /*
 488                 * pick up core.bare and core.worktree from per-worktree
 489                 * config if present
 490                 */
 491                strbuf_addf(&sb, "%s/config.worktree", gitdir);
 492                git_config_from_file(read_worktree_config, sb.buf, candidate);
 493                strbuf_release(&sb);
 494                has_common = 0;
 495        }
 496
 497        if (!has_common) {
 498                if (candidate->is_bare != -1) {
 499                        is_bare_repository_cfg = candidate->is_bare;
 500                        if (is_bare_repository_cfg == 1)
 501                                inside_work_tree = -1;
 502                }
 503                if (candidate->work_tree) {
 504                        free(git_work_tree_cfg);
 505                        git_work_tree_cfg = xstrdup(candidate->work_tree);
 506                        inside_work_tree = -1;
 507                }
 508        }
 509
 510        return 0;
 511}
 512
 513static void init_repository_format(struct repository_format *format)
 514{
 515        const struct repository_format fresh = REPOSITORY_FORMAT_INIT;
 516
 517        memcpy(format, &fresh, sizeof(fresh));
 518}
 519
 520int read_repository_format(struct repository_format *format, const char *path)
 521{
 522        clear_repository_format(format);
 523        git_config_from_file(check_repo_format, path, format);
 524        if (format->version == -1)
 525                clear_repository_format(format);
 526        return format->version;
 527}
 528
 529void clear_repository_format(struct repository_format *format)
 530{
 531        string_list_clear(&format->unknown_extensions, 0);
 532        free(format->work_tree);
 533        free(format->partial_clone);
 534        init_repository_format(format);
 535}
 536
 537int verify_repository_format(const struct repository_format *format,
 538                             struct strbuf *err)
 539{
 540        if (GIT_REPO_VERSION_READ < format->version) {
 541                strbuf_addf(err, _("Expected git repo version <= %d, found %d"),
 542                            GIT_REPO_VERSION_READ, format->version);
 543                return -1;
 544        }
 545
 546        if (format->version >= 1 && format->unknown_extensions.nr) {
 547                int i;
 548
 549                strbuf_addstr(err, _("unknown repository extensions found:"));
 550
 551                for (i = 0; i < format->unknown_extensions.nr; i++)
 552                        strbuf_addf(err, "\n\t%s",
 553                                    format->unknown_extensions.items[i].string);
 554                return -1;
 555        }
 556
 557        return 0;
 558}
 559
 560void read_gitfile_error_die(int error_code, const char *path, const char *dir)
 561{
 562        switch (error_code) {
 563        case READ_GITFILE_ERR_STAT_FAILED:
 564        case READ_GITFILE_ERR_NOT_A_FILE:
 565                /* non-fatal; follow return path */
 566                break;
 567        case READ_GITFILE_ERR_OPEN_FAILED:
 568                die_errno(_("error opening '%s'"), path);
 569        case READ_GITFILE_ERR_TOO_LARGE:
 570                die(_("too large to be a .git file: '%s'"), path);
 571        case READ_GITFILE_ERR_READ_FAILED:
 572                die(_("error reading %s"), path);
 573        case READ_GITFILE_ERR_INVALID_FORMAT:
 574                die(_("invalid gitfile format: %s"), path);
 575        case READ_GITFILE_ERR_NO_PATH:
 576                die(_("no path in gitfile: %s"), path);
 577        case READ_GITFILE_ERR_NOT_A_REPO:
 578                die(_("not a git repository: %s"), dir);
 579        default:
 580                BUG("unknown error code");
 581        }
 582}
 583
 584/*
 585 * Try to read the location of the git directory from the .git file,
 586 * return path to git directory if found. The return value comes from
 587 * a shared buffer.
 588 *
 589 * On failure, if return_error_code is not NULL, return_error_code
 590 * will be set to an error code and NULL will be returned. If
 591 * return_error_code is NULL the function will die instead (for most
 592 * cases).
 593 */
 594const char *read_gitfile_gently(const char *path, int *return_error_code)
 595{
 596        const int max_file_size = 1 << 20;  /* 1MB */
 597        int error_code = 0;
 598        char *buf = NULL;
 599        char *dir = NULL;
 600        const char *slash;
 601        struct stat st;
 602        int fd;
 603        ssize_t len;
 604
 605        if (stat(path, &st)) {
 606                /* NEEDSWORK: discern between ENOENT vs other errors */
 607                error_code = READ_GITFILE_ERR_STAT_FAILED;
 608                goto cleanup_return;
 609        }
 610        if (!S_ISREG(st.st_mode)) {
 611                error_code = READ_GITFILE_ERR_NOT_A_FILE;
 612                goto cleanup_return;
 613        }
 614        if (st.st_size > max_file_size) {
 615                error_code = READ_GITFILE_ERR_TOO_LARGE;
 616                goto cleanup_return;
 617        }
 618        fd = open(path, O_RDONLY);
 619        if (fd < 0) {
 620                error_code = READ_GITFILE_ERR_OPEN_FAILED;
 621                goto cleanup_return;
 622        }
 623        buf = xmallocz(st.st_size);
 624        len = read_in_full(fd, buf, st.st_size);
 625        close(fd);
 626        if (len != st.st_size) {
 627                error_code = READ_GITFILE_ERR_READ_FAILED;
 628                goto cleanup_return;
 629        }
 630        if (!starts_with(buf, "gitdir: ")) {
 631                error_code = READ_GITFILE_ERR_INVALID_FORMAT;
 632                goto cleanup_return;
 633        }
 634        while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 635                len--;
 636        if (len < 9) {
 637                error_code = READ_GITFILE_ERR_NO_PATH;
 638                goto cleanup_return;
 639        }
 640        buf[len] = '\0';
 641        dir = buf + 8;
 642
 643        if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
 644                size_t pathlen = slash+1 - path;
 645                dir = xstrfmt("%.*s%.*s", (int)pathlen, path,
 646                              (int)(len - 8), buf + 8);
 647                free(buf);
 648                buf = dir;
 649        }
 650        if (!is_git_directory(dir)) {
 651                error_code = READ_GITFILE_ERR_NOT_A_REPO;
 652                goto cleanup_return;
 653        }
 654        path = real_path(dir);
 655
 656cleanup_return:
 657        if (return_error_code)
 658                *return_error_code = error_code;
 659        else if (error_code)
 660                read_gitfile_error_die(error_code, path, dir);
 661
 662        free(buf);
 663        return error_code ? NULL : path;
 664}
 665
 666static const char *setup_explicit_git_dir(const char *gitdirenv,
 667                                          struct strbuf *cwd,
 668                                          struct repository_format *repo_fmt,
 669                                          int *nongit_ok)
 670{
 671        const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 672        const char *worktree;
 673        char *gitfile;
 674        int offset;
 675
 676        if (PATH_MAX - 40 < strlen(gitdirenv))
 677                die(_("'$%s' too big"), GIT_DIR_ENVIRONMENT);
 678
 679        gitfile = (char*)read_gitfile(gitdirenv);
 680        if (gitfile) {
 681                gitfile = xstrdup(gitfile);
 682                gitdirenv = gitfile;
 683        }
 684
 685        if (!is_git_directory(gitdirenv)) {
 686                if (nongit_ok) {
 687                        *nongit_ok = 1;
 688                        free(gitfile);
 689                        return NULL;
 690                }
 691                die(_("not a git repository: '%s'"), gitdirenv);
 692        }
 693
 694        if (check_repository_format_gently(gitdirenv, repo_fmt, nongit_ok)) {
 695                free(gitfile);
 696                return NULL;
 697        }
 698
 699        /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
 700        if (work_tree_env)
 701                set_git_work_tree(work_tree_env);
 702        else if (is_bare_repository_cfg > 0) {
 703                if (git_work_tree_cfg) {
 704                        /* #22.2, #30 */
 705                        warning("core.bare and core.worktree do not make sense");
 706                        work_tree_config_is_bogus = 1;
 707                }
 708
 709                /* #18, #26 */
 710                set_git_dir(gitdirenv);
 711                free(gitfile);
 712                return NULL;
 713        }
 714        else if (git_work_tree_cfg) { /* #6, #14 */
 715                if (is_absolute_path(git_work_tree_cfg))
 716                        set_git_work_tree(git_work_tree_cfg);
 717                else {
 718                        char *core_worktree;
 719                        if (chdir(gitdirenv))
 720                                die_errno(_("cannot chdir to '%s'"), gitdirenv);
 721                        if (chdir(git_work_tree_cfg))
 722                                die_errno(_("cannot chdir to '%s'"), git_work_tree_cfg);
 723                        core_worktree = xgetcwd();
 724                        if (chdir(cwd->buf))
 725                                die_errno(_("cannot come back to cwd"));
 726                        set_git_work_tree(core_worktree);
 727                        free(core_worktree);
 728                }
 729        }
 730        else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
 731                /* #16d */
 732                set_git_dir(gitdirenv);
 733                free(gitfile);
 734                return NULL;
 735        }
 736        else /* #2, #10 */
 737                set_git_work_tree(".");
 738
 739        /* set_git_work_tree() must have been called by now */
 740        worktree = get_git_work_tree();
 741
 742        /* both get_git_work_tree() and cwd are already normalized */
 743        if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */
 744                set_git_dir(gitdirenv);
 745                free(gitfile);
 746                return NULL;
 747        }
 748
 749        offset = dir_inside_of(cwd->buf, worktree);
 750        if (offset >= 0) {      /* cwd inside worktree? */
 751                set_git_dir(real_path(gitdirenv));
 752                if (chdir(worktree))
 753                        die_errno(_("cannot chdir to '%s'"), worktree);
 754                strbuf_addch(cwd, '/');
 755                free(gitfile);
 756                return cwd->buf + offset;
 757        }
 758
 759        /* cwd outside worktree */
 760        set_git_dir(gitdirenv);
 761        free(gitfile);
 762        return NULL;
 763}
 764
 765static const char *setup_discovered_git_dir(const char *gitdir,
 766                                            struct strbuf *cwd, int offset,
 767                                            struct repository_format *repo_fmt,
 768                                            int *nongit_ok)
 769{
 770        if (check_repository_format_gently(gitdir, repo_fmt, nongit_ok))
 771                return NULL;
 772
 773        /* --work-tree is set without --git-dir; use discovered one */
 774        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 775                char *to_free = NULL;
 776                const char *ret;
 777
 778                if (offset != cwd->len && !is_absolute_path(gitdir))
 779                        gitdir = to_free = real_pathdup(gitdir, 1);
 780                if (chdir(cwd->buf))
 781                        die_errno(_("cannot come back to cwd"));
 782                ret = setup_explicit_git_dir(gitdir, cwd, repo_fmt, nongit_ok);
 783                free(to_free);
 784                return ret;
 785        }
 786
 787        /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 788        if (is_bare_repository_cfg > 0) {
 789                set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir));
 790                if (chdir(cwd->buf))
 791                        die_errno(_("cannot come back to cwd"));
 792                return NULL;
 793        }
 794
 795        /* #0, #1, #5, #8, #9, #12, #13 */
 796        set_git_work_tree(".");
 797        if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
 798                set_git_dir(gitdir);
 799        inside_git_dir = 0;
 800        inside_work_tree = 1;
 801        if (offset >= cwd->len)
 802                return NULL;
 803
 804        /* Make "offset" point past the '/' (already the case for root dirs) */
 805        if (offset != offset_1st_component(cwd->buf))
 806                offset++;
 807        /* Add a '/' at the end */
 808        strbuf_addch(cwd, '/');
 809        return cwd->buf + offset;
 810}
 811
 812/* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
 813static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
 814                                      struct repository_format *repo_fmt,
 815                                      int *nongit_ok)
 816{
 817        int root_len;
 818
 819        if (check_repository_format_gently(".", repo_fmt, nongit_ok))
 820                return NULL;
 821
 822        setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 823
 824        /* --work-tree is set without --git-dir; use discovered one */
 825        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 826                static const char *gitdir;
 827
 828                gitdir = offset == cwd->len ? "." : xmemdupz(cwd->buf, offset);
 829                if (chdir(cwd->buf))
 830                        die_errno(_("cannot come back to cwd"));
 831                return setup_explicit_git_dir(gitdir, cwd, repo_fmt, nongit_ok);
 832        }
 833
 834        inside_git_dir = 1;
 835        inside_work_tree = 0;
 836        if (offset != cwd->len) {
 837                if (chdir(cwd->buf))
 838                        die_errno(_("cannot come back to cwd"));
 839                root_len = offset_1st_component(cwd->buf);
 840                strbuf_setlen(cwd, offset > root_len ? offset : root_len);
 841                set_git_dir(cwd->buf);
 842        }
 843        else
 844                set_git_dir(".");
 845        return NULL;
 846}
 847
 848static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
 849{
 850        struct stat buf;
 851        if (stat(path, &buf)) {
 852                die_errno(_("failed to stat '%*s%s%s'"),
 853                                prefix_len,
 854                                prefix ? prefix : "",
 855                                prefix ? "/" : "", path);
 856        }
 857        return buf.st_dev;
 858}
 859
 860/*
 861 * A "string_list_each_func_t" function that canonicalizes an entry
 862 * from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or
 863 * discards it if unusable.  The presence of an empty entry in
 864 * GIT_CEILING_DIRECTORIES turns off canonicalization for all
 865 * subsequent entries.
 866 */
 867static int canonicalize_ceiling_entry(struct string_list_item *item,
 868                                      void *cb_data)
 869{
 870        int *empty_entry_found = cb_data;
 871        char *ceil = item->string;
 872
 873        if (!*ceil) {
 874                *empty_entry_found = 1;
 875                return 0;
 876        } else if (!is_absolute_path(ceil)) {
 877                return 0;
 878        } else if (*empty_entry_found) {
 879                /* Keep entry but do not canonicalize it */
 880                return 1;
 881        } else {
 882                char *real_path = real_pathdup(ceil, 0);
 883                if (!real_path) {
 884                        return 0;
 885                }
 886                free(item->string);
 887                item->string = real_path;
 888                return 1;
 889        }
 890}
 891
 892enum discovery_result {
 893        GIT_DIR_NONE = 0,
 894        GIT_DIR_EXPLICIT,
 895        GIT_DIR_DISCOVERED,
 896        GIT_DIR_BARE,
 897        /* these are errors */
 898        GIT_DIR_HIT_CEILING = -1,
 899        GIT_DIR_HIT_MOUNT_POINT = -2,
 900        GIT_DIR_INVALID_GITFILE = -3
 901};
 902
 903/*
 904 * We cannot decide in this function whether we are in the work tree or
 905 * not, since the config can only be read _after_ this function was called.
 906 *
 907 * Also, we avoid changing any global state (such as the current working
 908 * directory) to allow early callers.
 909 *
 910 * The directory where the search should start needs to be passed in via the
 911 * `dir` parameter; upon return, the `dir` buffer will contain the path of
 912 * the directory where the search ended, and `gitdir` will contain the path of
 913 * the discovered .git/ directory, if any. If `gitdir` is not absolute, it
 914 * is relative to `dir` (i.e. *not* necessarily the cwd).
 915 */
 916static enum discovery_result setup_git_directory_gently_1(struct strbuf *dir,
 917                                                          struct strbuf *gitdir,
 918                                                          int die_on_error)
 919{
 920        const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 921        struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
 922        const char *gitdirenv;
 923        int ceil_offset = -1, min_offset = offset_1st_component(dir->buf);
 924        dev_t current_device = 0;
 925        int one_filesystem = 1;
 926
 927        /*
 928         * If GIT_DIR is set explicitly, we're not going
 929         * to do any discovery, but we still do repository
 930         * validation.
 931         */
 932        gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 933        if (gitdirenv) {
 934                strbuf_addstr(gitdir, gitdirenv);
 935                return GIT_DIR_EXPLICIT;
 936        }
 937
 938        if (env_ceiling_dirs) {
 939                int empty_entry_found = 0;
 940
 941                string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
 942                filter_string_list(&ceiling_dirs, 0,
 943                                   canonicalize_ceiling_entry, &empty_entry_found);
 944                ceil_offset = longest_ancestor_length(dir->buf, &ceiling_dirs);
 945                string_list_clear(&ceiling_dirs, 0);
 946        }
 947
 948        if (ceil_offset < 0)
 949                ceil_offset = min_offset - 2;
 950
 951        if (min_offset && min_offset == dir->len &&
 952            !is_dir_sep(dir->buf[min_offset - 1])) {
 953                strbuf_addch(dir, '/');
 954                min_offset++;
 955        }
 956
 957        /*
 958         * Test in the following order (relative to the dir):
 959         * - .git (file containing "gitdir: <path>")
 960         * - .git/
 961         * - ./ (bare)
 962         * - ../.git
 963         * - ../.git/
 964         * - ../ (bare)
 965         * - ../../.git
 966         *   etc.
 967         */
 968        one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
 969        if (one_filesystem)
 970                current_device = get_device_or_die(dir->buf, NULL, 0);
 971        for (;;) {
 972                int offset = dir->len, error_code = 0;
 973
 974                if (offset > min_offset)
 975                        strbuf_addch(dir, '/');
 976                strbuf_addstr(dir, DEFAULT_GIT_DIR_ENVIRONMENT);
 977                gitdirenv = read_gitfile_gently(dir->buf, die_on_error ?
 978                                                NULL : &error_code);
 979                if (!gitdirenv) {
 980                        if (die_on_error ||
 981                            error_code == READ_GITFILE_ERR_NOT_A_FILE) {
 982                                /* NEEDSWORK: fail if .git is not file nor dir */
 983                                if (is_git_directory(dir->buf))
 984                                        gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
 985                        } else if (error_code != READ_GITFILE_ERR_STAT_FAILED)
 986                                return GIT_DIR_INVALID_GITFILE;
 987                }
 988                strbuf_setlen(dir, offset);
 989                if (gitdirenv) {
 990                        strbuf_addstr(gitdir, gitdirenv);
 991                        return GIT_DIR_DISCOVERED;
 992                }
 993
 994                if (is_git_directory(dir->buf)) {
 995                        strbuf_addstr(gitdir, ".");
 996                        return GIT_DIR_BARE;
 997                }
 998
 999                if (offset <= min_offset)
1000                        return GIT_DIR_HIT_CEILING;
1001
1002                while (--offset > ceil_offset && !is_dir_sep(dir->buf[offset]))
1003                        ; /* continue */
1004                if (offset <= ceil_offset)
1005                        return GIT_DIR_HIT_CEILING;
1006
1007                strbuf_setlen(dir, offset > min_offset ?  offset : min_offset);
1008                if (one_filesystem &&
1009                    current_device != get_device_or_die(dir->buf, NULL, offset))
1010                        return GIT_DIR_HIT_MOUNT_POINT;
1011        }
1012}
1013
1014int discover_git_directory(struct strbuf *commondir,
1015                           struct strbuf *gitdir)
1016{
1017        struct strbuf dir = STRBUF_INIT, err = STRBUF_INIT;
1018        size_t gitdir_offset = gitdir->len, cwd_len;
1019        size_t commondir_offset = commondir->len;
1020        struct repository_format candidate = REPOSITORY_FORMAT_INIT;
1021
1022        if (strbuf_getcwd(&dir))
1023                return -1;
1024
1025        cwd_len = dir.len;
1026        if (setup_git_directory_gently_1(&dir, gitdir, 0) <= 0) {
1027                strbuf_release(&dir);
1028                return -1;
1029        }
1030
1031        /*
1032         * The returned gitdir is relative to dir, and if dir does not reflect
1033         * the current working directory, we simply make the gitdir absolute.
1034         */
1035        if (dir.len < cwd_len && !is_absolute_path(gitdir->buf + gitdir_offset)) {
1036                /* Avoid a trailing "/." */
1037                if (!strcmp(".", gitdir->buf + gitdir_offset))
1038                        strbuf_setlen(gitdir, gitdir_offset);
1039                else
1040                        strbuf_addch(&dir, '/');
1041                strbuf_insert(gitdir, gitdir_offset, dir.buf, dir.len);
1042        }
1043
1044        get_common_dir(commondir, gitdir->buf + gitdir_offset);
1045
1046        strbuf_reset(&dir);
1047        strbuf_addf(&dir, "%s/config", commondir->buf + commondir_offset);
1048        read_repository_format(&candidate, dir.buf);
1049        strbuf_release(&dir);
1050
1051        if (verify_repository_format(&candidate, &err) < 0) {
1052                warning("ignoring git dir '%s': %s",
1053                        gitdir->buf + gitdir_offset, err.buf);
1054                strbuf_release(&err);
1055                strbuf_setlen(commondir, commondir_offset);
1056                strbuf_setlen(gitdir, gitdir_offset);
1057                clear_repository_format(&candidate);
1058                return -1;
1059        }
1060
1061        clear_repository_format(&candidate);
1062        return 0;
1063}
1064
1065const char *setup_git_directory_gently(int *nongit_ok)
1066{
1067        static struct strbuf cwd = STRBUF_INIT;
1068        struct strbuf dir = STRBUF_INIT, gitdir = STRBUF_INIT;
1069        const char *prefix = NULL;
1070        struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT;
1071
1072        /*
1073         * We may have read an incomplete configuration before
1074         * setting-up the git directory. If so, clear the cache so
1075         * that the next queries to the configuration reload complete
1076         * configuration (including the per-repo config file that we
1077         * ignored previously).
1078         */
1079        git_config_clear();
1080
1081        /*
1082         * Let's assume that we are in a git repository.
1083         * If it turns out later that we are somewhere else, the value will be
1084         * updated accordingly.
1085         */
1086        if (nongit_ok)
1087                *nongit_ok = 0;
1088
1089        if (strbuf_getcwd(&cwd))
1090                die_errno(_("Unable to read current working directory"));
1091        strbuf_addbuf(&dir, &cwd);
1092
1093        switch (setup_git_directory_gently_1(&dir, &gitdir, 1)) {
1094        case GIT_DIR_EXPLICIT:
1095                prefix = setup_explicit_git_dir(gitdir.buf, &cwd, &repo_fmt, nongit_ok);
1096                break;
1097        case GIT_DIR_DISCOVERED:
1098                if (dir.len < cwd.len && chdir(dir.buf))
1099                        die(_("cannot change to '%s'"), dir.buf);
1100                prefix = setup_discovered_git_dir(gitdir.buf, &cwd, dir.len,
1101                                                  &repo_fmt, nongit_ok);
1102                break;
1103        case GIT_DIR_BARE:
1104                if (dir.len < cwd.len && chdir(dir.buf))
1105                        die(_("cannot change to '%s'"), dir.buf);
1106                prefix = setup_bare_git_dir(&cwd, dir.len, &repo_fmt, nongit_ok);
1107                break;
1108        case GIT_DIR_HIT_CEILING:
1109                if (!nongit_ok)
1110                        die(_("not a git repository (or any of the parent directories): %s"),
1111                            DEFAULT_GIT_DIR_ENVIRONMENT);
1112                *nongit_ok = 1;
1113                break;
1114        case GIT_DIR_HIT_MOUNT_POINT:
1115                if (!nongit_ok)
1116                        die(_("not a git repository (or any parent up to mount point %s)\n"
1117                              "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set)."),
1118                            dir.buf);
1119                *nongit_ok = 1;
1120                break;
1121        case GIT_DIR_NONE:
1122                /*
1123                 * As a safeguard against setup_git_directory_gently_1 returning
1124                 * this value, fallthrough to BUG. Otherwise it is possible to
1125                 * set startup_info->have_repository to 1 when we did nothing to
1126                 * find a repository.
1127                 */
1128        default:
1129                BUG("unhandled setup_git_directory_1() result");
1130        }
1131
1132        /*
1133         * At this point, nongit_ok is stable. If it is non-NULL and points
1134         * to a non-zero value, then this means that we haven't found a
1135         * repository and that the caller expects startup_info to reflect
1136         * this.
1137         *
1138         * Regardless of the state of nongit_ok, startup_info->prefix and
1139         * the GIT_PREFIX environment variable must always match. For details
1140         * see Documentation/config/alias.txt.
1141         */
1142        if (nongit_ok && *nongit_ok) {
1143                startup_info->have_repository = 0;
1144                startup_info->prefix = NULL;
1145                setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
1146        } else {
1147                startup_info->have_repository = 1;
1148                startup_info->prefix = prefix;
1149                if (prefix)
1150                        setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
1151                else
1152                        setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
1153        }
1154
1155        /*
1156         * Not all paths through the setup code will call 'set_git_dir()' (which
1157         * directly sets up the environment) so in order to guarantee that the
1158         * environment is in a consistent state after setup, explicitly setup
1159         * the environment if we have a repository.
1160         *
1161         * NEEDSWORK: currently we allow bogus GIT_DIR values to be set in some
1162         * code paths so we also need to explicitly setup the environment if
1163         * the user has set GIT_DIR.  It may be beneficial to disallow bogus
1164         * GIT_DIR values at some point in the future.
1165         */
1166        if (/* GIT_DIR_EXPLICIT, GIT_DIR_DISCOVERED, GIT_DIR_BARE */
1167            startup_info->have_repository ||
1168            /* GIT_DIR_EXPLICIT */
1169            getenv(GIT_DIR_ENVIRONMENT)) {
1170                if (!the_repository->gitdir) {
1171                        const char *gitdir = getenv(GIT_DIR_ENVIRONMENT);
1172                        if (!gitdir)
1173                                gitdir = DEFAULT_GIT_DIR_ENVIRONMENT;
1174                        setup_git_env(gitdir);
1175                }
1176                if (startup_info->have_repository)
1177                        repo_set_hash_algo(the_repository, repo_fmt.hash_algo);
1178        }
1179
1180        strbuf_release(&dir);
1181        strbuf_release(&gitdir);
1182        clear_repository_format(&repo_fmt);
1183
1184        return prefix;
1185}
1186
1187int git_config_perm(const char *var, const char *value)
1188{
1189        int i;
1190        char *endptr;
1191
1192        if (value == NULL)
1193                return PERM_GROUP;
1194
1195        if (!strcmp(value, "umask"))
1196                return PERM_UMASK;
1197        if (!strcmp(value, "group"))
1198                return PERM_GROUP;
1199        if (!strcmp(value, "all") ||
1200            !strcmp(value, "world") ||
1201            !strcmp(value, "everybody"))
1202                return PERM_EVERYBODY;
1203
1204        /* Parse octal numbers */
1205        i = strtol(value, &endptr, 8);
1206
1207        /* If not an octal number, maybe true/false? */
1208        if (*endptr != 0)
1209                return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
1210
1211        /*
1212         * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
1213         * a chmod value to restrict to.
1214         */
1215        switch (i) {
1216        case PERM_UMASK:               /* 0 */
1217                return PERM_UMASK;
1218        case OLD_PERM_GROUP:           /* 1 */
1219                return PERM_GROUP;
1220        case OLD_PERM_EVERYBODY:       /* 2 */
1221                return PERM_EVERYBODY;
1222        }
1223
1224        /* A filemode value was given: 0xxx */
1225
1226        if ((i & 0600) != 0600)
1227                die(_("problem with core.sharedRepository filemode value "
1228                    "(0%.3o).\nThe owner of files must always have "
1229                    "read and write permissions."), i);
1230
1231        /*
1232         * Mask filemode value. Others can not get write permission.
1233         * x flags for directories are handled separately.
1234         */
1235        return -(i & 0666);
1236}
1237
1238void check_repository_format(void)
1239{
1240        struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT;
1241        check_repository_format_gently(get_git_dir(), &repo_fmt, NULL);
1242        startup_info->have_repository = 1;
1243        clear_repository_format(&repo_fmt);
1244}
1245
1246/*
1247 * Returns the "prefix", a path to the current working directory
1248 * relative to the work tree root, or NULL, if the current working
1249 * directory is not a strict subdirectory of the work tree root. The
1250 * prefix always ends with a '/' character.
1251 */
1252const char *setup_git_directory(void)
1253{
1254        return setup_git_directory_gently(NULL);
1255}
1256
1257const char *resolve_gitdir_gently(const char *suspect, int *return_error_code)
1258{
1259        if (is_git_directory(suspect))
1260                return suspect;
1261        return read_gitfile_gently(suspect, return_error_code);
1262}
1263
1264/* if any standard file descriptor is missing open it to /dev/null */
1265void sanitize_stdfds(void)
1266{
1267        int fd = open("/dev/null", O_RDWR, 0);
1268        while (fd != -1 && fd < 2)
1269                fd = dup(fd);
1270        if (fd == -1)
1271                die_errno(_("open /dev/null or dup failed"));
1272        if (fd > 2)
1273                close(fd);
1274}
1275
1276int daemonize(void)
1277{
1278#ifdef NO_POSIX_GOODIES
1279        errno = ENOSYS;
1280        return -1;
1281#else
1282        switch (fork()) {
1283                case 0:
1284                        break;
1285                case -1:
1286                        die_errno(_("fork failed"));
1287                default:
1288                        exit(0);
1289        }
1290        if (setsid() == -1)
1291                die_errno(_("setsid failed"));
1292        close(0);
1293        close(1);
1294        close(2);
1295        sanitize_stdfds();
1296        return 0;
1297#endif
1298}