setup.con commit Merge branch 'bw/config-h' (f31d23a)
   1#include "cache.h"
   2#include "config.h"
   3#include "dir.h"
   4#include "string-list.h"
   5
   6static int inside_git_dir = -1;
   7static int inside_work_tree = -1;
   8static int work_tree_config_is_bogus;
   9
  10static struct startup_info the_startup_info;
  11struct startup_info *startup_info = &the_startup_info;
  12
  13/*
  14 * The input parameter must contain an absolute path, and it must already be
  15 * normalized.
  16 *
  17 * Find the part of an absolute path that lies inside the work tree by
  18 * dereferencing symlinks outside the work tree, for example:
  19 * /dir1/repo/dir2/file   (work tree is /dir1/repo)      -> dir2/file
  20 * /dir/file              (work tree is /)               -> dir/file
  21 * /dir/symlink1/symlink2 (symlink1 points to work tree) -> symlink2
  22 * /dir/repolink/file     (repolink points to /dir/repo) -> file
  23 * /dir/repo              (exactly equal to work tree)   -> (empty string)
  24 */
  25static int abspath_part_inside_repo(char *path)
  26{
  27        size_t len;
  28        size_t wtlen;
  29        char *path0;
  30        int off;
  31        const char *work_tree = get_git_work_tree();
  32
  33        if (!work_tree)
  34                return -1;
  35        wtlen = strlen(work_tree);
  36        len = strlen(path);
  37        off = offset_1st_component(path);
  38
  39        /* check if work tree is already the prefix */
  40        if (wtlen <= len && !strncmp(path, work_tree, wtlen)) {
  41                if (path[wtlen] == '/') {
  42                        memmove(path, path + wtlen + 1, len - wtlen);
  43                        return 0;
  44                } else if (path[wtlen - 1] == '/' || path[wtlen] == '\0') {
  45                        /* work tree is the root, or the whole path */
  46                        memmove(path, path + wtlen, len - wtlen + 1);
  47                        return 0;
  48                }
  49                /* work tree might match beginning of a symlink to work tree */
  50                off = wtlen;
  51        }
  52        path0 = path;
  53        path += off;
  54
  55        /* check each '/'-terminated level */
  56        while (*path) {
  57                path++;
  58                if (*path == '/') {
  59                        *path = '\0';
  60                        if (strcmp(real_path(path0), work_tree) == 0) {
  61                                memmove(path0, path + 1, len - (path - path0));
  62                                return 0;
  63                        }
  64                        *path = '/';
  65                }
  66        }
  67
  68        /* check whole path */
  69        if (strcmp(real_path(path0), work_tree) == 0) {
  70                *path0 = '\0';
  71                return 0;
  72        }
  73
  74        return -1;
  75}
  76
  77/*
  78 * Normalize "path", prepending the "prefix" for relative paths. If
  79 * remaining_prefix is not NULL, return the actual prefix still
  80 * remains in the path. For example, prefix = sub1/sub2/ and path is
  81 *
  82 *  foo          -> sub1/sub2/foo  (full prefix)
  83 *  ../foo       -> sub1/foo       (remaining prefix is sub1/)
  84 *  ../../bar    -> bar            (no remaining prefix)
  85 *  ../../sub1/sub2/foo -> sub1/sub2/foo (but no remaining prefix)
  86 *  `pwd`/../bar -> sub1/bar       (no remaining prefix)
  87 */
  88char *prefix_path_gently(const char *prefix, int len,
  89                         int *remaining_prefix, const char *path)
  90{
  91        const char *orig = path;
  92        char *sanitized;
  93        if (is_absolute_path(orig)) {
  94                sanitized = xmallocz(strlen(path));
  95                if (remaining_prefix)
  96                        *remaining_prefix = 0;
  97                if (normalize_path_copy_len(sanitized, path, remaining_prefix)) {
  98                        free(sanitized);
  99                        return NULL;
 100                }
 101                if (abspath_part_inside_repo(sanitized)) {
 102                        free(sanitized);
 103                        return NULL;
 104                }
 105        } else {
 106                sanitized = xstrfmt("%.*s%s", len, len ? prefix : "", path);
 107                if (remaining_prefix)
 108                        *remaining_prefix = len;
 109                if (normalize_path_copy_len(sanitized, sanitized, remaining_prefix)) {
 110                        free(sanitized);
 111                        return NULL;
 112                }
 113        }
 114        return sanitized;
 115}
 116
 117char *prefix_path(const char *prefix, int len, const char *path)
 118{
 119        char *r = prefix_path_gently(prefix, len, NULL, path);
 120        if (!r)
 121                die("'%s' is outside repository", path);
 122        return r;
 123}
 124
 125int path_inside_repo(const char *prefix, const char *path)
 126{
 127        int len = prefix ? strlen(prefix) : 0;
 128        char *r = prefix_path_gently(prefix, len, NULL, path);
 129        if (r) {
 130                free(r);
 131                return 1;
 132        }
 133        return 0;
 134}
 135
 136int check_filename(const char *prefix, const char *arg)
 137{
 138        char *to_free = NULL;
 139        struct stat st;
 140
 141        if (skip_prefix(arg, ":/", &arg)) {
 142                if (!*arg) /* ":/" is root dir, always exists */
 143                        return 1;
 144                prefix = NULL;
 145        } else if (skip_prefix(arg, ":!", &arg) ||
 146                   skip_prefix(arg, ":^", &arg)) {
 147                if (!*arg) /* excluding everything is silly, but allowed */
 148                        return 1;
 149        }
 150
 151        if (prefix)
 152                arg = to_free = prefix_filename(prefix, arg);
 153
 154        if (!lstat(arg, &st)) {
 155                free(to_free);
 156                return 1; /* file exists */
 157        }
 158        if (is_missing_file_error(errno)) {
 159                free(to_free);
 160                return 0; /* file does not exist */
 161        }
 162        die_errno("failed to stat '%s'", arg);
 163}
 164
 165static void NORETURN die_verify_filename(const char *prefix,
 166                                         const char *arg,
 167                                         int diagnose_misspelt_rev)
 168{
 169        if (!diagnose_misspelt_rev)
 170                die(_("%s: no such path in the working tree.\n"
 171                      "Use 'git <command> -- <path>...' to specify paths that do not exist locally."),
 172                    arg);
 173        /*
 174         * Saying "'(icase)foo' does not exist in the index" when the
 175         * user gave us ":(icase)foo" is just stupid.  A magic pathspec
 176         * begins with a colon and is followed by a non-alnum; do not
 177         * let maybe_die_on_misspelt_object_name() even trigger.
 178         */
 179        if (!(arg[0] == ':' && !isalnum(arg[1])))
 180                maybe_die_on_misspelt_object_name(arg, prefix);
 181
 182        /* ... or fall back the most general message. */
 183        die(_("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
 184              "Use '--' to separate paths from revisions, like this:\n"
 185              "'git <command> [<revision>...] -- [<file>...]'"), arg);
 186
 187}
 188
 189/*
 190 * Check for arguments that don't resolve as actual files,
 191 * but which look sufficiently like pathspecs that we'll consider
 192 * them such for the purposes of rev/pathspec DWIM parsing.
 193 */
 194static int looks_like_pathspec(const char *arg)
 195{
 196        /* anything with a wildcard character */
 197        if (!no_wildcard(arg))
 198                return 1;
 199
 200        /* long-form pathspec magic */
 201        if (starts_with(arg, ":("))
 202                return 1;
 203
 204        return 0;
 205}
 206
 207/*
 208 * Verify a filename that we got as an argument for a pathspec
 209 * entry. Note that a filename that begins with "-" never verifies
 210 * as true, because even if such a filename were to exist, we want
 211 * it to be preceded by the "--" marker (or we want the user to
 212 * use a format like "./-filename")
 213 *
 214 * The "diagnose_misspelt_rev" is used to provide a user-friendly
 215 * diagnosis when dying upon finding that "name" is not a pathname.
 216 * If set to 1, the diagnosis will try to diagnose "name" as an
 217 * invalid object name (e.g. HEAD:foo). If set to 0, the diagnosis
 218 * will only complain about an inexisting file.
 219 *
 220 * This function is typically called to check that a "file or rev"
 221 * argument is unambiguous. In this case, the caller will want
 222 * diagnose_misspelt_rev == 1 when verifying the first non-rev
 223 * argument (which could have been a revision), and
 224 * diagnose_misspelt_rev == 0 for the next ones (because we already
 225 * saw a filename, there's not ambiguity anymore).
 226 */
 227void verify_filename(const char *prefix,
 228                     const char *arg,
 229                     int diagnose_misspelt_rev)
 230{
 231        if (*arg == '-')
 232                die("bad flag '%s' used after filename", arg);
 233        if (looks_like_pathspec(arg) || check_filename(prefix, arg))
 234                return;
 235        die_verify_filename(prefix, arg, diagnose_misspelt_rev);
 236}
 237
 238/*
 239 * Opposite of the above: the command line did not have -- marker
 240 * and we parsed the arg as a refname.  It should not be interpretable
 241 * as a filename.
 242 */
 243void verify_non_filename(const char *prefix, const char *arg)
 244{
 245        if (!is_inside_work_tree() || is_inside_git_dir())
 246                return;
 247        if (*arg == '-')
 248                return; /* flag */
 249        if (!check_filename(prefix, arg))
 250                return;
 251        die(_("ambiguous argument '%s': both revision and filename\n"
 252              "Use '--' to separate paths from revisions, like this:\n"
 253              "'git <command> [<revision>...] -- [<file>...]'"), arg);
 254}
 255
 256int get_common_dir(struct strbuf *sb, const char *gitdir)
 257{
 258        const char *git_env_common_dir = getenv(GIT_COMMON_DIR_ENVIRONMENT);
 259        if (git_env_common_dir) {
 260                strbuf_addstr(sb, git_env_common_dir);
 261                return 1;
 262        } else {
 263                return get_common_dir_noenv(sb, gitdir);
 264        }
 265}
 266
 267int get_common_dir_noenv(struct strbuf *sb, const char *gitdir)
 268{
 269        struct strbuf data = STRBUF_INIT;
 270        struct strbuf path = STRBUF_INIT;
 271        int ret = 0;
 272
 273        strbuf_addf(&path, "%s/commondir", gitdir);
 274        if (file_exists(path.buf)) {
 275                if (strbuf_read_file(&data, path.buf, 0) <= 0)
 276                        die_errno(_("failed to read %s"), path.buf);
 277                while (data.len && (data.buf[data.len - 1] == '\n' ||
 278                                    data.buf[data.len - 1] == '\r'))
 279                        data.len--;
 280                data.buf[data.len] = '\0';
 281                strbuf_reset(&path);
 282                if (!is_absolute_path(data.buf))
 283                        strbuf_addf(&path, "%s/", gitdir);
 284                strbuf_addbuf(&path, &data);
 285                strbuf_add_real_path(sb, path.buf);
 286                ret = 1;
 287        } else {
 288                strbuf_addstr(sb, gitdir);
 289        }
 290
 291        strbuf_release(&data);
 292        strbuf_release(&path);
 293        return ret;
 294}
 295
 296/*
 297 * Test if it looks like we're at a git directory.
 298 * We want to see:
 299 *
 300 *  - either an objects/ directory _or_ the proper
 301 *    GIT_OBJECT_DIRECTORY environment variable
 302 *  - a refs/ directory
 303 *  - either a HEAD symlink or a HEAD file that is formatted as
 304 *    a proper "ref:", or a regular file HEAD that has a properly
 305 *    formatted sha1 object name.
 306 */
 307int is_git_directory(const char *suspect)
 308{
 309        struct strbuf path = STRBUF_INIT;
 310        int ret = 0;
 311        size_t len;
 312
 313        /* Check worktree-related signatures */
 314        strbuf_addf(&path, "%s/HEAD", suspect);
 315        if (validate_headref(path.buf))
 316                goto done;
 317
 318        strbuf_reset(&path);
 319        get_common_dir(&path, suspect);
 320        len = path.len;
 321
 322        /* Check non-worktree-related signatures */
 323        if (getenv(DB_ENVIRONMENT)) {
 324                if (access(getenv(DB_ENVIRONMENT), X_OK))
 325                        goto done;
 326        }
 327        else {
 328                strbuf_setlen(&path, len);
 329                strbuf_addstr(&path, "/objects");
 330                if (access(path.buf, X_OK))
 331                        goto done;
 332        }
 333
 334        strbuf_setlen(&path, len);
 335        strbuf_addstr(&path, "/refs");
 336        if (access(path.buf, X_OK))
 337                goto done;
 338
 339        ret = 1;
 340done:
 341        strbuf_release(&path);
 342        return ret;
 343}
 344
 345int is_nonbare_repository_dir(struct strbuf *path)
 346{
 347        int ret = 0;
 348        int gitfile_error;
 349        size_t orig_path_len = path->len;
 350        assert(orig_path_len != 0);
 351        strbuf_complete(path, '/');
 352        strbuf_addstr(path, ".git");
 353        if (read_gitfile_gently(path->buf, &gitfile_error) || is_git_directory(path->buf))
 354                ret = 1;
 355        if (gitfile_error == READ_GITFILE_ERR_OPEN_FAILED ||
 356            gitfile_error == READ_GITFILE_ERR_READ_FAILED)
 357                ret = 1;
 358        strbuf_setlen(path, orig_path_len);
 359        return ret;
 360}
 361
 362int is_inside_git_dir(void)
 363{
 364        if (inside_git_dir < 0)
 365                inside_git_dir = is_inside_dir(get_git_dir());
 366        return inside_git_dir;
 367}
 368
 369int is_inside_work_tree(void)
 370{
 371        if (inside_work_tree < 0)
 372                inside_work_tree = is_inside_dir(get_git_work_tree());
 373        return inside_work_tree;
 374}
 375
 376void setup_work_tree(void)
 377{
 378        const char *work_tree, *git_dir;
 379        static int initialized = 0;
 380
 381        if (initialized)
 382                return;
 383
 384        if (work_tree_config_is_bogus)
 385                die("unable to set up work tree using invalid config");
 386
 387        work_tree = get_git_work_tree();
 388        git_dir = get_git_dir();
 389        if (!is_absolute_path(git_dir))
 390                git_dir = real_path(get_git_dir());
 391        if (!work_tree || chdir(work_tree))
 392                die("This operation must be run in a work tree");
 393
 394        /*
 395         * Make sure subsequent git processes find correct worktree
 396         * if $GIT_WORK_TREE is set relative
 397         */
 398        if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 399                setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 400
 401        set_git_dir(remove_leading_path(git_dir, work_tree));
 402        initialized = 1;
 403}
 404
 405static int check_repo_format(const char *var, const char *value, void *vdata)
 406{
 407        struct repository_format *data = vdata;
 408        const char *ext;
 409
 410        if (strcmp(var, "core.repositoryformatversion") == 0)
 411                data->version = git_config_int(var, value);
 412        else if (skip_prefix(var, "extensions.", &ext)) {
 413                /*
 414                 * record any known extensions here; otherwise,
 415                 * we fall through to recording it as unknown, and
 416                 * check_repository_format will complain
 417                 */
 418                if (!strcmp(ext, "noop"))
 419                        ;
 420                else if (!strcmp(ext, "preciousobjects"))
 421                        data->precious_objects = git_config_bool(var, value);
 422                else
 423                        string_list_append(&data->unknown_extensions, ext);
 424        } else if (strcmp(var, "core.bare") == 0) {
 425                data->is_bare = git_config_bool(var, value);
 426        } else if (strcmp(var, "core.worktree") == 0) {
 427                if (!value)
 428                        return config_error_nonbool(var);
 429                data->work_tree = xstrdup(value);
 430        }
 431        return 0;
 432}
 433
 434static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 435{
 436        struct strbuf sb = STRBUF_INIT;
 437        struct strbuf err = STRBUF_INIT;
 438        struct repository_format candidate;
 439        int has_common;
 440
 441        has_common = get_common_dir(&sb, gitdir);
 442        strbuf_addstr(&sb, "/config");
 443        read_repository_format(&candidate, sb.buf);
 444        strbuf_release(&sb);
 445
 446        /*
 447         * For historical use of check_repository_format() in git-init,
 448         * we treat a missing config as a silent "ok", even when nongit_ok
 449         * is unset.
 450         */
 451        if (candidate.version < 0)
 452                return 0;
 453
 454        if (verify_repository_format(&candidate, &err) < 0) {
 455                if (nongit_ok) {
 456                        warning("%s", err.buf);
 457                        strbuf_release(&err);
 458                        *nongit_ok = -1;
 459                        return -1;
 460                }
 461                die("%s", err.buf);
 462        }
 463
 464        repository_format_precious_objects = candidate.precious_objects;
 465        string_list_clear(&candidate.unknown_extensions, 0);
 466        if (!has_common) {
 467                if (candidate.is_bare != -1) {
 468                        is_bare_repository_cfg = candidate.is_bare;
 469                        if (is_bare_repository_cfg == 1)
 470                                inside_work_tree = -1;
 471                }
 472                if (candidate.work_tree) {
 473                        free(git_work_tree_cfg);
 474                        git_work_tree_cfg = candidate.work_tree;
 475                        inside_work_tree = -1;
 476                }
 477        } else {
 478                free(candidate.work_tree);
 479        }
 480
 481        return 0;
 482}
 483
 484int read_repository_format(struct repository_format *format, const char *path)
 485{
 486        memset(format, 0, sizeof(*format));
 487        format->version = -1;
 488        format->is_bare = -1;
 489        string_list_init(&format->unknown_extensions, 1);
 490        git_config_from_file(check_repo_format, path, format);
 491        return format->version;
 492}
 493
 494int verify_repository_format(const struct repository_format *format,
 495                             struct strbuf *err)
 496{
 497        if (GIT_REPO_VERSION_READ < format->version) {
 498                strbuf_addf(err, _("Expected git repo version <= %d, found %d"),
 499                            GIT_REPO_VERSION_READ, format->version);
 500                return -1;
 501        }
 502
 503        if (format->version >= 1 && format->unknown_extensions.nr) {
 504                int i;
 505
 506                strbuf_addstr(err, _("unknown repository extensions found:"));
 507
 508                for (i = 0; i < format->unknown_extensions.nr; i++)
 509                        strbuf_addf(err, "\n\t%s",
 510                                    format->unknown_extensions.items[i].string);
 511                return -1;
 512        }
 513
 514        return 0;
 515}
 516
 517void read_gitfile_error_die(int error_code, const char *path, const char *dir)
 518{
 519        switch (error_code) {
 520        case READ_GITFILE_ERR_STAT_FAILED:
 521        case READ_GITFILE_ERR_NOT_A_FILE:
 522                /* non-fatal; follow return path */
 523                break;
 524        case READ_GITFILE_ERR_OPEN_FAILED:
 525                die_errno("Error opening '%s'", path);
 526        case READ_GITFILE_ERR_TOO_LARGE:
 527                die("Too large to be a .git file: '%s'", path);
 528        case READ_GITFILE_ERR_READ_FAILED:
 529                die("Error reading %s", path);
 530        case READ_GITFILE_ERR_INVALID_FORMAT:
 531                die("Invalid gitfile format: %s", path);
 532        case READ_GITFILE_ERR_NO_PATH:
 533                die("No path in gitfile: %s", path);
 534        case READ_GITFILE_ERR_NOT_A_REPO:
 535                die("Not a git repository: %s", dir);
 536        default:
 537                die("BUG: unknown error code");
 538        }
 539}
 540
 541/*
 542 * Try to read the location of the git directory from the .git file,
 543 * return path to git directory if found.
 544 *
 545 * On failure, if return_error_code is not NULL, return_error_code
 546 * will be set to an error code and NULL will be returned. If
 547 * return_error_code is NULL the function will die instead (for most
 548 * cases).
 549 */
 550const char *read_gitfile_gently(const char *path, int *return_error_code)
 551{
 552        const int max_file_size = 1 << 20;  /* 1MB */
 553        int error_code = 0;
 554        char *buf = NULL;
 555        char *dir = NULL;
 556        const char *slash;
 557        struct stat st;
 558        int fd;
 559        ssize_t len;
 560
 561        if (stat(path, &st)) {
 562                /* NEEDSWORK: discern between ENOENT vs other errors */
 563                error_code = READ_GITFILE_ERR_STAT_FAILED;
 564                goto cleanup_return;
 565        }
 566        if (!S_ISREG(st.st_mode)) {
 567                error_code = READ_GITFILE_ERR_NOT_A_FILE;
 568                goto cleanup_return;
 569        }
 570        if (st.st_size > max_file_size) {
 571                error_code = READ_GITFILE_ERR_TOO_LARGE;
 572                goto cleanup_return;
 573        }
 574        fd = open(path, O_RDONLY);
 575        if (fd < 0) {
 576                error_code = READ_GITFILE_ERR_OPEN_FAILED;
 577                goto cleanup_return;
 578        }
 579        buf = xmallocz(st.st_size);
 580        len = read_in_full(fd, buf, st.st_size);
 581        close(fd);
 582        if (len != st.st_size) {
 583                error_code = READ_GITFILE_ERR_READ_FAILED;
 584                goto cleanup_return;
 585        }
 586        if (!starts_with(buf, "gitdir: ")) {
 587                error_code = READ_GITFILE_ERR_INVALID_FORMAT;
 588                goto cleanup_return;
 589        }
 590        while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 591                len--;
 592        if (len < 9) {
 593                error_code = READ_GITFILE_ERR_NO_PATH;
 594                goto cleanup_return;
 595        }
 596        buf[len] = '\0';
 597        dir = buf + 8;
 598
 599        if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
 600                size_t pathlen = slash+1 - path;
 601                dir = xstrfmt("%.*s%.*s", (int)pathlen, path,
 602                              (int)(len - 8), buf + 8);
 603                free(buf);
 604                buf = dir;
 605        }
 606        if (!is_git_directory(dir)) {
 607                error_code = READ_GITFILE_ERR_NOT_A_REPO;
 608                goto cleanup_return;
 609        }
 610        path = real_path(dir);
 611
 612cleanup_return:
 613        if (return_error_code)
 614                *return_error_code = error_code;
 615        else if (error_code)
 616                read_gitfile_error_die(error_code, path, dir);
 617
 618        free(buf);
 619        return error_code ? NULL : path;
 620}
 621
 622static const char *setup_explicit_git_dir(const char *gitdirenv,
 623                                          struct strbuf *cwd,
 624                                          int *nongit_ok)
 625{
 626        const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 627        const char *worktree;
 628        char *gitfile;
 629        int offset;
 630
 631        if (PATH_MAX - 40 < strlen(gitdirenv))
 632                die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 633
 634        gitfile = (char*)read_gitfile(gitdirenv);
 635        if (gitfile) {
 636                gitfile = xstrdup(gitfile);
 637                gitdirenv = gitfile;
 638        }
 639
 640        if (!is_git_directory(gitdirenv)) {
 641                if (nongit_ok) {
 642                        *nongit_ok = 1;
 643                        free(gitfile);
 644                        return NULL;
 645                }
 646                die("Not a git repository: '%s'", gitdirenv);
 647        }
 648
 649        if (check_repository_format_gently(gitdirenv, nongit_ok)) {
 650                free(gitfile);
 651                return NULL;
 652        }
 653
 654        /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
 655        if (work_tree_env)
 656                set_git_work_tree(work_tree_env);
 657        else if (is_bare_repository_cfg > 0) {
 658                if (git_work_tree_cfg) {
 659                        /* #22.2, #30 */
 660                        warning("core.bare and core.worktree do not make sense");
 661                        work_tree_config_is_bogus = 1;
 662                }
 663
 664                /* #18, #26 */
 665                set_git_dir(gitdirenv);
 666                free(gitfile);
 667                return NULL;
 668        }
 669        else if (git_work_tree_cfg) { /* #6, #14 */
 670                if (is_absolute_path(git_work_tree_cfg))
 671                        set_git_work_tree(git_work_tree_cfg);
 672                else {
 673                        char *core_worktree;
 674                        if (chdir(gitdirenv))
 675                                die_errno("Could not chdir to '%s'", gitdirenv);
 676                        if (chdir(git_work_tree_cfg))
 677                                die_errno("Could not chdir to '%s'", git_work_tree_cfg);
 678                        core_worktree = xgetcwd();
 679                        if (chdir(cwd->buf))
 680                                die_errno("Could not come back to cwd");
 681                        set_git_work_tree(core_worktree);
 682                        free(core_worktree);
 683                }
 684        }
 685        else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
 686                /* #16d */
 687                set_git_dir(gitdirenv);
 688                free(gitfile);
 689                return NULL;
 690        }
 691        else /* #2, #10 */
 692                set_git_work_tree(".");
 693
 694        /* set_git_work_tree() must have been called by now */
 695        worktree = get_git_work_tree();
 696
 697        /* both get_git_work_tree() and cwd are already normalized */
 698        if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */
 699                set_git_dir(gitdirenv);
 700                free(gitfile);
 701                return NULL;
 702        }
 703
 704        offset = dir_inside_of(cwd->buf, worktree);
 705        if (offset >= 0) {      /* cwd inside worktree? */
 706                set_git_dir(real_path(gitdirenv));
 707                if (chdir(worktree))
 708                        die_errno("Could not chdir to '%s'", worktree);
 709                strbuf_addch(cwd, '/');
 710                free(gitfile);
 711                return cwd->buf + offset;
 712        }
 713
 714        /* cwd outside worktree */
 715        set_git_dir(gitdirenv);
 716        free(gitfile);
 717        return NULL;
 718}
 719
 720static const char *setup_discovered_git_dir(const char *gitdir,
 721                                            struct strbuf *cwd, int offset,
 722                                            int *nongit_ok)
 723{
 724        if (check_repository_format_gently(gitdir, nongit_ok))
 725                return NULL;
 726
 727        /* --work-tree is set without --git-dir; use discovered one */
 728        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 729                char *to_free = NULL;
 730                const char *ret;
 731
 732                if (offset != cwd->len && !is_absolute_path(gitdir))
 733                        gitdir = to_free = real_pathdup(gitdir, 1);
 734                if (chdir(cwd->buf))
 735                        die_errno("Could not come back to cwd");
 736                ret = setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 737                free(to_free);
 738                return ret;
 739        }
 740
 741        /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 742        if (is_bare_repository_cfg > 0) {
 743                set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir));
 744                if (chdir(cwd->buf))
 745                        die_errno("Could not come back to cwd");
 746                return NULL;
 747        }
 748
 749        /* #0, #1, #5, #8, #9, #12, #13 */
 750        set_git_work_tree(".");
 751        if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
 752                set_git_dir(gitdir);
 753        inside_git_dir = 0;
 754        inside_work_tree = 1;
 755        if (offset == cwd->len)
 756                return NULL;
 757
 758        /* Make "offset" point past the '/' (already the case for root dirs) */
 759        if (offset != offset_1st_component(cwd->buf))
 760                offset++;
 761        /* Add a '/' at the end */
 762        strbuf_addch(cwd, '/');
 763        return cwd->buf + offset;
 764}
 765
 766/* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
 767static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
 768                                      int *nongit_ok)
 769{
 770        int root_len;
 771
 772        if (check_repository_format_gently(".", nongit_ok))
 773                return NULL;
 774
 775        setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 776
 777        /* --work-tree is set without --git-dir; use discovered one */
 778        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 779                static const char *gitdir;
 780
 781                gitdir = offset == cwd->len ? "." : xmemdupz(cwd->buf, offset);
 782                if (chdir(cwd->buf))
 783                        die_errno("Could not come back to cwd");
 784                return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 785        }
 786
 787        inside_git_dir = 1;
 788        inside_work_tree = 0;
 789        if (offset != cwd->len) {
 790                if (chdir(cwd->buf))
 791                        die_errno("Cannot come back to cwd");
 792                root_len = offset_1st_component(cwd->buf);
 793                strbuf_setlen(cwd, offset > root_len ? offset : root_len);
 794                set_git_dir(cwd->buf);
 795        }
 796        else
 797                set_git_dir(".");
 798        return NULL;
 799}
 800
 801static const char *setup_nongit(const char *cwd, int *nongit_ok)
 802{
 803        if (!nongit_ok)
 804                die(_("Not a git repository (or any of the parent directories): %s"), DEFAULT_GIT_DIR_ENVIRONMENT);
 805        if (chdir(cwd))
 806                die_errno(_("Cannot come back to cwd"));
 807        *nongit_ok = 1;
 808        return NULL;
 809}
 810
 811static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
 812{
 813        struct stat buf;
 814        if (stat(path, &buf)) {
 815                die_errno("failed to stat '%*s%s%s'",
 816                                prefix_len,
 817                                prefix ? prefix : "",
 818                                prefix ? "/" : "", path);
 819        }
 820        return buf.st_dev;
 821}
 822
 823/*
 824 * A "string_list_each_func_t" function that canonicalizes an entry
 825 * from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or
 826 * discards it if unusable.  The presence of an empty entry in
 827 * GIT_CEILING_DIRECTORIES turns off canonicalization for all
 828 * subsequent entries.
 829 */
 830static int canonicalize_ceiling_entry(struct string_list_item *item,
 831                                      void *cb_data)
 832{
 833        int *empty_entry_found = cb_data;
 834        char *ceil = item->string;
 835
 836        if (!*ceil) {
 837                *empty_entry_found = 1;
 838                return 0;
 839        } else if (!is_absolute_path(ceil)) {
 840                return 0;
 841        } else if (*empty_entry_found) {
 842                /* Keep entry but do not canonicalize it */
 843                return 1;
 844        } else {
 845                char *real_path = real_pathdup(ceil, 0);
 846                if (!real_path) {
 847                        return 0;
 848                }
 849                free(item->string);
 850                item->string = real_path;
 851                return 1;
 852        }
 853}
 854
 855enum discovery_result {
 856        GIT_DIR_NONE = 0,
 857        GIT_DIR_EXPLICIT,
 858        GIT_DIR_DISCOVERED,
 859        GIT_DIR_BARE,
 860        /* these are errors */
 861        GIT_DIR_HIT_CEILING = -1,
 862        GIT_DIR_HIT_MOUNT_POINT = -2,
 863        GIT_DIR_INVALID_GITFILE = -3
 864};
 865
 866/*
 867 * We cannot decide in this function whether we are in the work tree or
 868 * not, since the config can only be read _after_ this function was called.
 869 *
 870 * Also, we avoid changing any global state (such as the current working
 871 * directory) to allow early callers.
 872 *
 873 * The directory where the search should start needs to be passed in via the
 874 * `dir` parameter; upon return, the `dir` buffer will contain the path of
 875 * the directory where the search ended, and `gitdir` will contain the path of
 876 * the discovered .git/ directory, if any. If `gitdir` is not absolute, it
 877 * is relative to `dir` (i.e. *not* necessarily the cwd).
 878 */
 879static enum discovery_result setup_git_directory_gently_1(struct strbuf *dir,
 880                                                          struct strbuf *gitdir,
 881                                                          int die_on_error)
 882{
 883        const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 884        struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
 885        const char *gitdirenv;
 886        int ceil_offset = -1, min_offset = has_dos_drive_prefix(dir->buf) ? 3 : 1;
 887        dev_t current_device = 0;
 888        int one_filesystem = 1;
 889
 890        /*
 891         * If GIT_DIR is set explicitly, we're not going
 892         * to do any discovery, but we still do repository
 893         * validation.
 894         */
 895        gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 896        if (gitdirenv) {
 897                strbuf_addstr(gitdir, gitdirenv);
 898                return GIT_DIR_EXPLICIT;
 899        }
 900
 901        if (env_ceiling_dirs) {
 902                int empty_entry_found = 0;
 903
 904                string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
 905                filter_string_list(&ceiling_dirs, 0,
 906                                   canonicalize_ceiling_entry, &empty_entry_found);
 907                ceil_offset = longest_ancestor_length(dir->buf, &ceiling_dirs);
 908                string_list_clear(&ceiling_dirs, 0);
 909        }
 910
 911        if (ceil_offset < 0)
 912                ceil_offset = min_offset - 2;
 913
 914        /*
 915         * Test in the following order (relative to the dir):
 916         * - .git (file containing "gitdir: <path>")
 917         * - .git/
 918         * - ./ (bare)
 919         * - ../.git
 920         * - ../.git/
 921         * - ../ (bare)
 922         * - ../../.git/
 923         *   etc.
 924         */
 925        one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
 926        if (one_filesystem)
 927                current_device = get_device_or_die(dir->buf, NULL, 0);
 928        for (;;) {
 929                int offset = dir->len, error_code = 0;
 930
 931                if (offset > min_offset)
 932                        strbuf_addch(dir, '/');
 933                strbuf_addstr(dir, DEFAULT_GIT_DIR_ENVIRONMENT);
 934                gitdirenv = read_gitfile_gently(dir->buf, die_on_error ?
 935                                                NULL : &error_code);
 936                if (!gitdirenv) {
 937                        if (die_on_error ||
 938                            error_code == READ_GITFILE_ERR_NOT_A_FILE) {
 939                                /* NEEDSWORK: fail if .git is not file nor dir */
 940                                if (is_git_directory(dir->buf))
 941                                        gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
 942                        } else if (error_code != READ_GITFILE_ERR_STAT_FAILED)
 943                                return GIT_DIR_INVALID_GITFILE;
 944                }
 945                strbuf_setlen(dir, offset);
 946                if (gitdirenv) {
 947                        strbuf_addstr(gitdir, gitdirenv);
 948                        return GIT_DIR_DISCOVERED;
 949                }
 950
 951                if (is_git_directory(dir->buf)) {
 952                        strbuf_addstr(gitdir, ".");
 953                        return GIT_DIR_BARE;
 954                }
 955
 956                if (offset <= min_offset)
 957                        return GIT_DIR_HIT_CEILING;
 958
 959                while (--offset > ceil_offset && !is_dir_sep(dir->buf[offset]))
 960                        ; /* continue */
 961                if (offset <= ceil_offset)
 962                        return GIT_DIR_HIT_CEILING;
 963
 964                strbuf_setlen(dir, offset > min_offset ?  offset : min_offset);
 965                if (one_filesystem &&
 966                    current_device != get_device_or_die(dir->buf, NULL, offset))
 967                        return GIT_DIR_HIT_MOUNT_POINT;
 968        }
 969}
 970
 971int discover_git_directory(struct strbuf *commondir,
 972                           struct strbuf *gitdir)
 973{
 974        struct strbuf dir = STRBUF_INIT, err = STRBUF_INIT;
 975        size_t gitdir_offset = gitdir->len, cwd_len;
 976        size_t commondir_offset = commondir->len;
 977        struct repository_format candidate;
 978
 979        if (strbuf_getcwd(&dir))
 980                return -1;
 981
 982        cwd_len = dir.len;
 983        if (setup_git_directory_gently_1(&dir, gitdir, 0) <= 0) {
 984                strbuf_release(&dir);
 985                return -1;
 986        }
 987
 988        /*
 989         * The returned gitdir is relative to dir, and if dir does not reflect
 990         * the current working directory, we simply make the gitdir absolute.
 991         */
 992        if (dir.len < cwd_len && !is_absolute_path(gitdir->buf + gitdir_offset)) {
 993                /* Avoid a trailing "/." */
 994                if (!strcmp(".", gitdir->buf + gitdir_offset))
 995                        strbuf_setlen(gitdir, gitdir_offset);
 996                else
 997                        strbuf_addch(&dir, '/');
 998                strbuf_insert(gitdir, gitdir_offset, dir.buf, dir.len);
 999        }
1000
1001        get_common_dir(commondir, gitdir->buf + gitdir_offset);
1002
1003        strbuf_reset(&dir);
1004        strbuf_addf(&dir, "%s/config", commondir->buf + commondir_offset);
1005        read_repository_format(&candidate, dir.buf);
1006        strbuf_release(&dir);
1007
1008        if (verify_repository_format(&candidate, &err) < 0) {
1009                warning("ignoring git dir '%s': %s",
1010                        gitdir->buf + gitdir_offset, err.buf);
1011                strbuf_release(&err);
1012                strbuf_setlen(commondir, commondir_offset);
1013                strbuf_setlen(gitdir, gitdir_offset);
1014                return -1;
1015        }
1016
1017        return 0;
1018}
1019
1020const char *setup_git_directory_gently(int *nongit_ok)
1021{
1022        static struct strbuf cwd = STRBUF_INIT;
1023        struct strbuf dir = STRBUF_INIT, gitdir = STRBUF_INIT;
1024        const char *prefix, *env_prefix;
1025
1026        /*
1027         * We may have read an incomplete configuration before
1028         * setting-up the git directory. If so, clear the cache so
1029         * that the next queries to the configuration reload complete
1030         * configuration (including the per-repo config file that we
1031         * ignored previously).
1032         */
1033        git_config_clear();
1034
1035        /*
1036         * Let's assume that we are in a git repository.
1037         * If it turns out later that we are somewhere else, the value will be
1038         * updated accordingly.
1039         */
1040        if (nongit_ok)
1041                *nongit_ok = 0;
1042
1043        if (strbuf_getcwd(&cwd))
1044                die_errno(_("Unable to read current working directory"));
1045        strbuf_addbuf(&dir, &cwd);
1046
1047        switch (setup_git_directory_gently_1(&dir, &gitdir, 1)) {
1048        case GIT_DIR_NONE:
1049                prefix = NULL;
1050                break;
1051        case GIT_DIR_EXPLICIT:
1052                prefix = setup_explicit_git_dir(gitdir.buf, &cwd, nongit_ok);
1053                break;
1054        case GIT_DIR_DISCOVERED:
1055                if (dir.len < cwd.len && chdir(dir.buf))
1056                        die(_("Cannot change to '%s'"), dir.buf);
1057                prefix = setup_discovered_git_dir(gitdir.buf, &cwd, dir.len,
1058                                                  nongit_ok);
1059                break;
1060        case GIT_DIR_BARE:
1061                if (dir.len < cwd.len && chdir(dir.buf))
1062                        die(_("Cannot change to '%s'"), dir.buf);
1063                prefix = setup_bare_git_dir(&cwd, dir.len, nongit_ok);
1064                break;
1065        case GIT_DIR_HIT_CEILING:
1066                prefix = setup_nongit(cwd.buf, nongit_ok);
1067                break;
1068        case GIT_DIR_HIT_MOUNT_POINT:
1069                if (nongit_ok) {
1070                        *nongit_ok = 1;
1071                        strbuf_release(&cwd);
1072                        strbuf_release(&dir);
1073                        return NULL;
1074                }
1075                die(_("Not a git repository (or any parent up to mount point %s)\n"
1076                      "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set)."),
1077                    dir.buf);
1078        default:
1079                die("BUG: unhandled setup_git_directory_1() result");
1080        }
1081
1082        env_prefix = getenv(GIT_TOPLEVEL_PREFIX_ENVIRONMENT);
1083        if (env_prefix)
1084                prefix = env_prefix;
1085
1086        if (prefix)
1087                setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
1088        else
1089                setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
1090
1091        startup_info->have_repository = !nongit_ok || !*nongit_ok;
1092        startup_info->prefix = prefix;
1093
1094        strbuf_release(&dir);
1095        strbuf_release(&gitdir);
1096
1097        return prefix;
1098}
1099
1100int git_config_perm(const char *var, const char *value)
1101{
1102        int i;
1103        char *endptr;
1104
1105        if (value == NULL)
1106                return PERM_GROUP;
1107
1108        if (!strcmp(value, "umask"))
1109                return PERM_UMASK;
1110        if (!strcmp(value, "group"))
1111                return PERM_GROUP;
1112        if (!strcmp(value, "all") ||
1113            !strcmp(value, "world") ||
1114            !strcmp(value, "everybody"))
1115                return PERM_EVERYBODY;
1116
1117        /* Parse octal numbers */
1118        i = strtol(value, &endptr, 8);
1119
1120        /* If not an octal number, maybe true/false? */
1121        if (*endptr != 0)
1122                return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
1123
1124        /*
1125         * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
1126         * a chmod value to restrict to.
1127         */
1128        switch (i) {
1129        case PERM_UMASK:               /* 0 */
1130                return PERM_UMASK;
1131        case OLD_PERM_GROUP:           /* 1 */
1132                return PERM_GROUP;
1133        case OLD_PERM_EVERYBODY:       /* 2 */
1134                return PERM_EVERYBODY;
1135        }
1136
1137        /* A filemode value was given: 0xxx */
1138
1139        if ((i & 0600) != 0600)
1140                die(_("Problem with core.sharedRepository filemode value "
1141                    "(0%.3o).\nThe owner of files must always have "
1142                    "read and write permissions."), i);
1143
1144        /*
1145         * Mask filemode value. Others can not get write permission.
1146         * x flags for directories are handled separately.
1147         */
1148        return -(i & 0666);
1149}
1150
1151void check_repository_format(void)
1152{
1153        check_repository_format_gently(get_git_dir(), NULL);
1154        startup_info->have_repository = 1;
1155}
1156
1157/*
1158 * Returns the "prefix", a path to the current working directory
1159 * relative to the work tree root, or NULL, if the current working
1160 * directory is not a strict subdirectory of the work tree root. The
1161 * prefix always ends with a '/' character.
1162 */
1163const char *setup_git_directory(void)
1164{
1165        return setup_git_directory_gently(NULL);
1166}
1167
1168const char *resolve_gitdir_gently(const char *suspect, int *return_error_code)
1169{
1170        if (is_git_directory(suspect))
1171                return suspect;
1172        return read_gitfile_gently(suspect, return_error_code);
1173}
1174
1175/* if any standard file descriptor is missing open it to /dev/null */
1176void sanitize_stdfds(void)
1177{
1178        int fd = open("/dev/null", O_RDWR, 0);
1179        while (fd != -1 && fd < 2)
1180                fd = dup(fd);
1181        if (fd == -1)
1182                die_errno("open /dev/null or dup failed");
1183        if (fd > 2)
1184                close(fd);
1185}
1186
1187int daemonize(void)
1188{
1189#ifdef NO_POSIX_GOODIES
1190        errno = ENOSYS;
1191        return -1;
1192#else
1193        switch (fork()) {
1194                case 0:
1195                        break;
1196                case -1:
1197                        die_errno("fork failed");
1198                default:
1199                        exit(0);
1200        }
1201        if (setsid() == -1)
1202                die_errno("setsid failed");
1203        close(0);
1204        close(1);
1205        close(2);
1206        sanitize_stdfds();
1207        return 0;
1208#endif
1209}