setup.con commit Merge branch 'js/colored-push-errors' (a56fb3d)
   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
   8static int inside_git_dir = -1;
   9static int inside_work_tree = -1;
  10static int work_tree_config_is_bogus;
  11
  12static struct startup_info the_startup_info;
  13struct startup_info *startup_info = &the_startup_info;
  14
  15/*
  16 * The input parameter must contain an absolute path, and it must already be
  17 * normalized.
  18 *
  19 * Find the part of an absolute path that lies inside the work tree by
  20 * dereferencing symlinks outside the work tree, for example:
  21 * /dir1/repo/dir2/file   (work tree is /dir1/repo)      -> dir2/file
  22 * /dir/file              (work tree is /)               -> dir/file
  23 * /dir/symlink1/symlink2 (symlink1 points to work tree) -> symlink2
  24 * /dir/repolink/file     (repolink points to /dir/repo) -> file
  25 * /dir/repo              (exactly equal to work tree)   -> (empty string)
  26 */
  27static int abspath_part_inside_repo(char *path)
  28{
  29        size_t len;
  30        size_t wtlen;
  31        char *path0;
  32        int off;
  33        const char *work_tree = get_git_work_tree();
  34
  35        if (!work_tree)
  36                return -1;
  37        wtlen = strlen(work_tree);
  38        len = strlen(path);
  39        off = offset_1st_component(path);
  40
  41        /* check if work tree is already the prefix */
  42        if (wtlen <= len && !strncmp(path, work_tree, wtlen)) {
  43                if (path[wtlen] == '/') {
  44                        memmove(path, path + wtlen + 1, len - wtlen);
  45                        return 0;
  46                } else if (path[wtlen - 1] == '/' || path[wtlen] == '\0') {
  47                        /* work tree is the root, or the whole path */
  48                        memmove(path, path + wtlen, len - wtlen + 1);
  49                        return 0;
  50                }
  51                /* work tree might match beginning of a symlink to work tree */
  52                off = wtlen;
  53        }
  54        path0 = path;
  55        path += off;
  56
  57        /* check each '/'-terminated level */
  58        while (*path) {
  59                path++;
  60                if (*path == '/') {
  61                        *path = '\0';
  62                        if (strcmp(real_path(path0), work_tree) == 0) {
  63                                memmove(path0, path + 1, len - (path - path0));
  64                                return 0;
  65                        }
  66                        *path = '/';
  67                }
  68        }
  69
  70        /* check whole path */
  71        if (strcmp(real_path(path0), work_tree) == 0) {
  72                *path0 = '\0';
  73                return 0;
  74        }
  75
  76        return -1;
  77}
  78
  79/*
  80 * Normalize "path", prepending the "prefix" for relative paths. If
  81 * remaining_prefix is not NULL, return the actual prefix still
  82 * remains in the path. For example, prefix = sub1/sub2/ and path is
  83 *
  84 *  foo          -> sub1/sub2/foo  (full prefix)
  85 *  ../foo       -> sub1/foo       (remaining prefix is sub1/)
  86 *  ../../bar    -> bar            (no remaining prefix)
  87 *  ../../sub1/sub2/foo -> sub1/sub2/foo (but no remaining prefix)
  88 *  `pwd`/../bar -> sub1/bar       (no remaining prefix)
  89 */
  90char *prefix_path_gently(const char *prefix, int len,
  91                         int *remaining_prefix, const char *path)
  92{
  93        const char *orig = path;
  94        char *sanitized;
  95        if (is_absolute_path(orig)) {
  96                sanitized = xmallocz(strlen(path));
  97                if (remaining_prefix)
  98                        *remaining_prefix = 0;
  99                if (normalize_path_copy_len(sanitized, path, remaining_prefix)) {
 100                        free(sanitized);
 101                        return NULL;
 102                }
 103                if (abspath_part_inside_repo(sanitized)) {
 104                        free(sanitized);
 105                        return NULL;
 106                }
 107        } else {
 108                sanitized = xstrfmt("%.*s%s", len, len ? prefix : "", path);
 109                if (remaining_prefix)
 110                        *remaining_prefix = len;
 111                if (normalize_path_copy_len(sanitized, sanitized, remaining_prefix)) {
 112                        free(sanitized);
 113                        return NULL;
 114                }
 115        }
 116        return sanitized;
 117}
 118
 119char *prefix_path(const char *prefix, int len, const char *path)
 120{
 121        char *r = prefix_path_gently(prefix, len, NULL, path);
 122        if (!r)
 123                die(_("'%s' is outside repository"), path);
 124        return r;
 125}
 126
 127int path_inside_repo(const char *prefix, const char *path)
 128{
 129        int len = prefix ? strlen(prefix) : 0;
 130        char *r = prefix_path_gently(prefix, len, NULL, path);
 131        if (r) {
 132                free(r);
 133                return 1;
 134        }
 135        return 0;
 136}
 137
 138int check_filename(const char *prefix, const char *arg)
 139{
 140        char *to_free = NULL;
 141        struct stat st;
 142
 143        if (skip_prefix(arg, ":/", &arg)) {
 144                if (!*arg) /* ":/" is root dir, always exists */
 145                        return 1;
 146                prefix = NULL;
 147        } else if (skip_prefix(arg, ":!", &arg) ||
 148                   skip_prefix(arg, ":^", &arg)) {
 149                if (!*arg) /* excluding everything is silly, but allowed */
 150                        return 1;
 151        }
 152
 153        if (prefix)
 154                arg = to_free = prefix_filename(prefix, arg);
 155
 156        if (!lstat(arg, &st)) {
 157                free(to_free);
 158                return 1; /* file exists */
 159        }
 160        if (is_missing_file_error(errno)) {
 161                free(to_free);
 162                return 0; /* file does not exist */
 163        }
 164        die_errno(_("failed to stat '%s'"), arg);
 165}
 166
 167static void NORETURN die_verify_filename(const char *prefix,
 168                                         const char *arg,
 169                                         int diagnose_misspelt_rev)
 170{
 171        if (!diagnose_misspelt_rev)
 172                die(_("%s: no such path in the working tree.\n"
 173                      "Use 'git <command> -- <path>...' to specify paths that do not exist locally."),
 174                    arg);
 175        /*
 176         * Saying "'(icase)foo' does not exist in the index" when the
 177         * user gave us ":(icase)foo" is just stupid.  A magic pathspec
 178         * begins with a colon and is followed by a non-alnum; do not
 179         * let maybe_die_on_misspelt_object_name() even trigger.
 180         */
 181        if (!(arg[0] == ':' && !isalnum(arg[1])))
 182                maybe_die_on_misspelt_object_name(arg, prefix);
 183
 184        /* ... or fall back the most general message. */
 185        die(_("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
 186              "Use '--' to separate paths from revisions, like this:\n"
 187              "'git <command> [<revision>...] -- [<file>...]'"), arg);
 188
 189}
 190
 191/*
 192 * Check for arguments that don't resolve as actual files,
 193 * but which look sufficiently like pathspecs that we'll consider
 194 * them such for the purposes of rev/pathspec DWIM parsing.
 195 */
 196static int looks_like_pathspec(const char *arg)
 197{
 198        /* anything with a wildcard character */
 199        if (!no_wildcard(arg))
 200                return 1;
 201
 202        /* long-form pathspec magic */
 203        if (starts_with(arg, ":("))
 204                return 1;
 205
 206        return 0;
 207}
 208
 209/*
 210 * Verify a filename that we got as an argument for a pathspec
 211 * entry. Note that a filename that begins with "-" never verifies
 212 * as true, because even if such a filename were to exist, we want
 213 * it to be preceded by the "--" marker (or we want the user to
 214 * use a format like "./-filename")
 215 *
 216 * The "diagnose_misspelt_rev" is used to provide a user-friendly
 217 * diagnosis when dying upon finding that "name" is not a pathname.
 218 * If set to 1, the diagnosis will try to diagnose "name" as an
 219 * invalid object name (e.g. HEAD:foo). If set to 0, the diagnosis
 220 * will only complain about an inexisting file.
 221 *
 222 * This function is typically called to check that a "file or rev"
 223 * argument is unambiguous. In this case, the caller will want
 224 * diagnose_misspelt_rev == 1 when verifying the first non-rev
 225 * argument (which could have been a revision), and
 226 * diagnose_misspelt_rev == 0 for the next ones (because we already
 227 * saw a filename, there's not ambiguity anymore).
 228 */
 229void verify_filename(const char *prefix,
 230                     const char *arg,
 231                     int diagnose_misspelt_rev)
 232{
 233        if (*arg == '-')
 234                die(_("option '%s' must come before non-option arguments"), arg);
 235        if (looks_like_pathspec(arg) || check_filename(prefix, arg))
 236                return;
 237        die_verify_filename(prefix, arg, diagnose_misspelt_rev);
 238}
 239
 240/*
 241 * Opposite of the above: the command line did not have -- marker
 242 * and we parsed the arg as a refname.  It should not be interpretable
 243 * as a filename.
 244 */
 245void verify_non_filename(const char *prefix, const char *arg)
 246{
 247        if (!is_inside_work_tree() || is_inside_git_dir())
 248                return;
 249        if (*arg == '-')
 250                return; /* flag */
 251        if (!check_filename(prefix, arg))
 252                return;
 253        die(_("ambiguous argument '%s': both revision and filename\n"
 254              "Use '--' to separate paths from revisions, like this:\n"
 255              "'git <command> [<revision>...] -- [<file>...]'"), arg);
 256}
 257
 258int get_common_dir(struct strbuf *sb, const char *gitdir)
 259{
 260        const char *git_env_common_dir = getenv(GIT_COMMON_DIR_ENVIRONMENT);
 261        if (git_env_common_dir) {
 262                strbuf_addstr(sb, git_env_common_dir);
 263                return 1;
 264        } else {
 265                return get_common_dir_noenv(sb, gitdir);
 266        }
 267}
 268
 269int get_common_dir_noenv(struct strbuf *sb, const char *gitdir)
 270{
 271        struct strbuf data = STRBUF_INIT;
 272        struct strbuf path = STRBUF_INIT;
 273        int ret = 0;
 274
 275        strbuf_addf(&path, "%s/commondir", gitdir);
 276        if (file_exists(path.buf)) {
 277                if (strbuf_read_file(&data, path.buf, 0) <= 0)
 278                        die_errno(_("failed to read %s"), path.buf);
 279                while (data.len && (data.buf[data.len - 1] == '\n' ||
 280                                    data.buf[data.len - 1] == '\r'))
 281                        data.len--;
 282                data.buf[data.len] = '\0';
 283                strbuf_reset(&path);
 284                if (!is_absolute_path(data.buf))
 285                        strbuf_addf(&path, "%s/", gitdir);
 286                strbuf_addbuf(&path, &data);
 287                strbuf_add_real_path(sb, path.buf);
 288                ret = 1;
 289        } else {
 290                strbuf_addstr(sb, gitdir);
 291        }
 292
 293        strbuf_release(&data);
 294        strbuf_release(&path);
 295        return ret;
 296}
 297
 298/*
 299 * Test if it looks like we're at a git directory.
 300 * We want to see:
 301 *
 302 *  - either an objects/ directory _or_ the proper
 303 *    GIT_OBJECT_DIRECTORY environment variable
 304 *  - a refs/ directory
 305 *  - either a HEAD symlink or a HEAD file that is formatted as
 306 *    a proper "ref:", or a regular file HEAD that has a properly
 307 *    formatted sha1 object name.
 308 */
 309int is_git_directory(const char *suspect)
 310{
 311        struct strbuf path = STRBUF_INIT;
 312        int ret = 0;
 313        size_t len;
 314
 315        /* Check worktree-related signatures */
 316        strbuf_addstr(&path, suspect);
 317        strbuf_complete(&path, '/');
 318        strbuf_addstr(&path, "HEAD");
 319        if (validate_headref(path.buf))
 320                goto done;
 321
 322        strbuf_reset(&path);
 323        get_common_dir(&path, suspect);
 324        len = path.len;
 325
 326        /* Check non-worktree-related signatures */
 327        if (getenv(DB_ENVIRONMENT)) {
 328                if (access(getenv(DB_ENVIRONMENT), X_OK))
 329                        goto done;
 330        }
 331        else {
 332                strbuf_setlen(&path, len);
 333                strbuf_addstr(&path, "/objects");
 334                if (access(path.buf, X_OK))
 335                        goto done;
 336        }
 337
 338        strbuf_setlen(&path, len);
 339        strbuf_addstr(&path, "/refs");
 340        if (access(path.buf, X_OK))
 341                goto done;
 342
 343        ret = 1;
 344done:
 345        strbuf_release(&path);
 346        return ret;
 347}
 348
 349int is_nonbare_repository_dir(struct strbuf *path)
 350{
 351        int ret = 0;
 352        int gitfile_error;
 353        size_t orig_path_len = path->len;
 354        assert(orig_path_len != 0);
 355        strbuf_complete(path, '/');
 356        strbuf_addstr(path, ".git");
 357        if (read_gitfile_gently(path->buf, &gitfile_error) || is_git_directory(path->buf))
 358                ret = 1;
 359        if (gitfile_error == READ_GITFILE_ERR_OPEN_FAILED ||
 360            gitfile_error == READ_GITFILE_ERR_READ_FAILED)
 361                ret = 1;
 362        strbuf_setlen(path, orig_path_len);
 363        return ret;
 364}
 365
 366int is_inside_git_dir(void)
 367{
 368        if (inside_git_dir < 0)
 369                inside_git_dir = is_inside_dir(get_git_dir());
 370        return inside_git_dir;
 371}
 372
 373int is_inside_work_tree(void)
 374{
 375        if (inside_work_tree < 0)
 376                inside_work_tree = is_inside_dir(get_git_work_tree());
 377        return inside_work_tree;
 378}
 379
 380void setup_work_tree(void)
 381{
 382        const char *work_tree;
 383        static int initialized = 0;
 384
 385        if (initialized)
 386                return;
 387
 388        if (work_tree_config_is_bogus)
 389                die(_("unable to set up work tree using invalid config"));
 390
 391        work_tree = get_git_work_tree();
 392        if (!work_tree || chdir_notify(work_tree))
 393                die(_("this operation must be run in a work tree"));
 394
 395        /*
 396         * Make sure subsequent git processes find correct worktree
 397         * if $GIT_WORK_TREE is set relative
 398         */
 399        if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 400                setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 401
 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 if (!strcmp(ext, "partialclone")) {
 423                        if (!value)
 424                                return config_error_nonbool(var);
 425                        data->partial_clone = xstrdup(value);
 426                } else
 427                        string_list_append(&data->unknown_extensions, ext);
 428        } else if (strcmp(var, "core.bare") == 0) {
 429                data->is_bare = git_config_bool(var, value);
 430        } else if (strcmp(var, "core.worktree") == 0) {
 431                if (!value)
 432                        return config_error_nonbool(var);
 433                data->work_tree = xstrdup(value);
 434        }
 435        return 0;
 436}
 437
 438static int check_repository_format_gently(const char *gitdir, struct repository_format *candidate, int *nongit_ok)
 439{
 440        struct strbuf sb = STRBUF_INIT;
 441        struct strbuf err = STRBUF_INIT;
 442        int has_common;
 443
 444        has_common = get_common_dir(&sb, gitdir);
 445        strbuf_addstr(&sb, "/config");
 446        read_repository_format(candidate, sb.buf);
 447        strbuf_release(&sb);
 448
 449        /*
 450         * For historical use of check_repository_format() in git-init,
 451         * we treat a missing config as a silent "ok", even when nongit_ok
 452         * is unset.
 453         */
 454        if (candidate->version < 0)
 455                return 0;
 456
 457        if (verify_repository_format(candidate, &err) < 0) {
 458                if (nongit_ok) {
 459                        warning("%s", err.buf);
 460                        strbuf_release(&err);
 461                        *nongit_ok = -1;
 462                        return -1;
 463                }
 464                die("%s", err.buf);
 465        }
 466
 467        repository_format_precious_objects = candidate->precious_objects;
 468        repository_format_partial_clone = candidate->partial_clone;
 469        string_list_clear(&candidate->unknown_extensions, 0);
 470        if (!has_common) {
 471                if (candidate->is_bare != -1) {
 472                        is_bare_repository_cfg = candidate->is_bare;
 473                        if (is_bare_repository_cfg == 1)
 474                                inside_work_tree = -1;
 475                }
 476                if (candidate->work_tree) {
 477                        free(git_work_tree_cfg);
 478                        git_work_tree_cfg = candidate->work_tree;
 479                        inside_work_tree = -1;
 480                }
 481        } else {
 482                free(candidate->work_tree);
 483        }
 484
 485        return 0;
 486}
 487
 488int read_repository_format(struct repository_format *format, const char *path)
 489{
 490        memset(format, 0, sizeof(*format));
 491        format->version = -1;
 492        format->is_bare = -1;
 493        format->hash_algo = GIT_HASH_SHA1;
 494        string_list_init(&format->unknown_extensions, 1);
 495        git_config_from_file(check_repo_format, path, format);
 496        return format->version;
 497}
 498
 499int verify_repository_format(const struct repository_format *format,
 500                             struct strbuf *err)
 501{
 502        if (GIT_REPO_VERSION_READ < format->version) {
 503                strbuf_addf(err, _("Expected git repo version <= %d, found %d"),
 504                            GIT_REPO_VERSION_READ, format->version);
 505                return -1;
 506        }
 507
 508        if (format->version >= 1 && format->unknown_extensions.nr) {
 509                int i;
 510
 511                strbuf_addstr(err, _("unknown repository extensions found:"));
 512
 513                for (i = 0; i < format->unknown_extensions.nr; i++)
 514                        strbuf_addf(err, "\n\t%s",
 515                                    format->unknown_extensions.items[i].string);
 516                return -1;
 517        }
 518
 519        return 0;
 520}
 521
 522void read_gitfile_error_die(int error_code, const char *path, const char *dir)
 523{
 524        switch (error_code) {
 525        case READ_GITFILE_ERR_STAT_FAILED:
 526        case READ_GITFILE_ERR_NOT_A_FILE:
 527                /* non-fatal; follow return path */
 528                break;
 529        case READ_GITFILE_ERR_OPEN_FAILED:
 530                die_errno(_("error opening '%s'"), path);
 531        case READ_GITFILE_ERR_TOO_LARGE:
 532                die(_("too large to be a .git file: '%s'"), path);
 533        case READ_GITFILE_ERR_READ_FAILED:
 534                die(_("error reading %s"), path);
 535        case READ_GITFILE_ERR_INVALID_FORMAT:
 536                die(_("invalid gitfile format: %s"), path);
 537        case READ_GITFILE_ERR_NO_PATH:
 538                die(_("no path in gitfile: %s"), path);
 539        case READ_GITFILE_ERR_NOT_A_REPO:
 540                die(_("not a git repository: %s"), dir);
 541        default:
 542                die("BUG: unknown error code");
 543        }
 544}
 545
 546/*
 547 * Try to read the location of the git directory from the .git file,
 548 * return path to git directory if found. The return value comes from
 549 * a shared buffer.
 550 *
 551 * On failure, if return_error_code is not NULL, return_error_code
 552 * will be set to an error code and NULL will be returned. If
 553 * return_error_code is NULL the function will die instead (for most
 554 * cases).
 555 */
 556const char *read_gitfile_gently(const char *path, int *return_error_code)
 557{
 558        const int max_file_size = 1 << 20;  /* 1MB */
 559        int error_code = 0;
 560        char *buf = NULL;
 561        char *dir = NULL;
 562        const char *slash;
 563        struct stat st;
 564        int fd;
 565        ssize_t len;
 566
 567        if (stat(path, &st)) {
 568                /* NEEDSWORK: discern between ENOENT vs other errors */
 569                error_code = READ_GITFILE_ERR_STAT_FAILED;
 570                goto cleanup_return;
 571        }
 572        if (!S_ISREG(st.st_mode)) {
 573                error_code = READ_GITFILE_ERR_NOT_A_FILE;
 574                goto cleanup_return;
 575        }
 576        if (st.st_size > max_file_size) {
 577                error_code = READ_GITFILE_ERR_TOO_LARGE;
 578                goto cleanup_return;
 579        }
 580        fd = open(path, O_RDONLY);
 581        if (fd < 0) {
 582                error_code = READ_GITFILE_ERR_OPEN_FAILED;
 583                goto cleanup_return;
 584        }
 585        buf = xmallocz(st.st_size);
 586        len = read_in_full(fd, buf, st.st_size);
 587        close(fd);
 588        if (len != st.st_size) {
 589                error_code = READ_GITFILE_ERR_READ_FAILED;
 590                goto cleanup_return;
 591        }
 592        if (!starts_with(buf, "gitdir: ")) {
 593                error_code = READ_GITFILE_ERR_INVALID_FORMAT;
 594                goto cleanup_return;
 595        }
 596        while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 597                len--;
 598        if (len < 9) {
 599                error_code = READ_GITFILE_ERR_NO_PATH;
 600                goto cleanup_return;
 601        }
 602        buf[len] = '\0';
 603        dir = buf + 8;
 604
 605        if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
 606                size_t pathlen = slash+1 - path;
 607                dir = xstrfmt("%.*s%.*s", (int)pathlen, path,
 608                              (int)(len - 8), buf + 8);
 609                free(buf);
 610                buf = dir;
 611        }
 612        if (!is_git_directory(dir)) {
 613                error_code = READ_GITFILE_ERR_NOT_A_REPO;
 614                goto cleanup_return;
 615        }
 616        path = real_path(dir);
 617
 618cleanup_return:
 619        if (return_error_code)
 620                *return_error_code = error_code;
 621        else if (error_code)
 622                read_gitfile_error_die(error_code, path, dir);
 623
 624        free(buf);
 625        return error_code ? NULL : path;
 626}
 627
 628static const char *setup_explicit_git_dir(const char *gitdirenv,
 629                                          struct strbuf *cwd,
 630                                          struct repository_format *repo_fmt,
 631                                          int *nongit_ok)
 632{
 633        const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 634        const char *worktree;
 635        char *gitfile;
 636        int offset;
 637
 638        if (PATH_MAX - 40 < strlen(gitdirenv))
 639                die(_("'$%s' too big"), GIT_DIR_ENVIRONMENT);
 640
 641        gitfile = (char*)read_gitfile(gitdirenv);
 642        if (gitfile) {
 643                gitfile = xstrdup(gitfile);
 644                gitdirenv = gitfile;
 645        }
 646
 647        if (!is_git_directory(gitdirenv)) {
 648                if (nongit_ok) {
 649                        *nongit_ok = 1;
 650                        free(gitfile);
 651                        return NULL;
 652                }
 653                die(_("not a git repository: '%s'"), gitdirenv);
 654        }
 655
 656        if (check_repository_format_gently(gitdirenv, repo_fmt, nongit_ok)) {
 657                free(gitfile);
 658                return NULL;
 659        }
 660
 661        /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
 662        if (work_tree_env)
 663                set_git_work_tree(work_tree_env);
 664        else if (is_bare_repository_cfg > 0) {
 665                if (git_work_tree_cfg) {
 666                        /* #22.2, #30 */
 667                        warning("core.bare and core.worktree do not make sense");
 668                        work_tree_config_is_bogus = 1;
 669                }
 670
 671                /* #18, #26 */
 672                set_git_dir(gitdirenv);
 673                free(gitfile);
 674                return NULL;
 675        }
 676        else if (git_work_tree_cfg) { /* #6, #14 */
 677                if (is_absolute_path(git_work_tree_cfg))
 678                        set_git_work_tree(git_work_tree_cfg);
 679                else {
 680                        char *core_worktree;
 681                        if (chdir(gitdirenv))
 682                                die_errno(_("cannot chdir to '%s'"), gitdirenv);
 683                        if (chdir(git_work_tree_cfg))
 684                                die_errno(_("cannot chdir to '%s'"), git_work_tree_cfg);
 685                        core_worktree = xgetcwd();
 686                        if (chdir(cwd->buf))
 687                                die_errno(_("cannot come back to cwd"));
 688                        set_git_work_tree(core_worktree);
 689                        free(core_worktree);
 690                }
 691        }
 692        else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
 693                /* #16d */
 694                set_git_dir(gitdirenv);
 695                free(gitfile);
 696                return NULL;
 697        }
 698        else /* #2, #10 */
 699                set_git_work_tree(".");
 700
 701        /* set_git_work_tree() must have been called by now */
 702        worktree = get_git_work_tree();
 703
 704        /* both get_git_work_tree() and cwd are already normalized */
 705        if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */
 706                set_git_dir(gitdirenv);
 707                free(gitfile);
 708                return NULL;
 709        }
 710
 711        offset = dir_inside_of(cwd->buf, worktree);
 712        if (offset >= 0) {      /* cwd inside worktree? */
 713                set_git_dir(real_path(gitdirenv));
 714                if (chdir(worktree))
 715                        die_errno(_("cannot chdir to '%s'"), worktree);
 716                strbuf_addch(cwd, '/');
 717                free(gitfile);
 718                return cwd->buf + offset;
 719        }
 720
 721        /* cwd outside worktree */
 722        set_git_dir(gitdirenv);
 723        free(gitfile);
 724        return NULL;
 725}
 726
 727static const char *setup_discovered_git_dir(const char *gitdir,
 728                                            struct strbuf *cwd, int offset,
 729                                            struct repository_format *repo_fmt,
 730                                            int *nongit_ok)
 731{
 732        if (check_repository_format_gently(gitdir, repo_fmt, nongit_ok))
 733                return NULL;
 734
 735        /* --work-tree is set without --git-dir; use discovered one */
 736        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 737                char *to_free = NULL;
 738                const char *ret;
 739
 740                if (offset != cwd->len && !is_absolute_path(gitdir))
 741                        gitdir = to_free = real_pathdup(gitdir, 1);
 742                if (chdir(cwd->buf))
 743                        die_errno(_("cannot come back to cwd"));
 744                ret = setup_explicit_git_dir(gitdir, cwd, repo_fmt, nongit_ok);
 745                free(to_free);
 746                return ret;
 747        }
 748
 749        /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 750        if (is_bare_repository_cfg > 0) {
 751                set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir));
 752                if (chdir(cwd->buf))
 753                        die_errno(_("cannot come back to cwd"));
 754                return NULL;
 755        }
 756
 757        /* #0, #1, #5, #8, #9, #12, #13 */
 758        set_git_work_tree(".");
 759        if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
 760                set_git_dir(gitdir);
 761        inside_git_dir = 0;
 762        inside_work_tree = 1;
 763        if (offset == cwd->len)
 764                return NULL;
 765
 766        /* Make "offset" point past the '/' (already the case for root dirs) */
 767        if (offset != offset_1st_component(cwd->buf))
 768                offset++;
 769        /* Add a '/' at the end */
 770        strbuf_addch(cwd, '/');
 771        return cwd->buf + offset;
 772}
 773
 774/* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
 775static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
 776                                      struct repository_format *repo_fmt,
 777                                      int *nongit_ok)
 778{
 779        int root_len;
 780
 781        if (check_repository_format_gently(".", repo_fmt, nongit_ok))
 782                return NULL;
 783
 784        setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 785
 786        /* --work-tree is set without --git-dir; use discovered one */
 787        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 788                static const char *gitdir;
 789
 790                gitdir = offset == cwd->len ? "." : xmemdupz(cwd->buf, offset);
 791                if (chdir(cwd->buf))
 792                        die_errno(_("cannot come back to cwd"));
 793                return setup_explicit_git_dir(gitdir, cwd, repo_fmt, nongit_ok);
 794        }
 795
 796        inside_git_dir = 1;
 797        inside_work_tree = 0;
 798        if (offset != cwd->len) {
 799                if (chdir(cwd->buf))
 800                        die_errno(_("cannot come back to cwd"));
 801                root_len = offset_1st_component(cwd->buf);
 802                strbuf_setlen(cwd, offset > root_len ? offset : root_len);
 803                set_git_dir(cwd->buf);
 804        }
 805        else
 806                set_git_dir(".");
 807        return NULL;
 808}
 809
 810static const char *setup_nongit(const char *cwd, int *nongit_ok)
 811{
 812        if (!nongit_ok)
 813                die(_("not a git repository (or any of the parent directories): %s"), DEFAULT_GIT_DIR_ENVIRONMENT);
 814        if (chdir(cwd))
 815                die_errno(_("cannot come back to cwd"));
 816        *nongit_ok = 1;
 817        return NULL;
 818}
 819
 820static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
 821{
 822        struct stat buf;
 823        if (stat(path, &buf)) {
 824                die_errno(_("failed to stat '%*s%s%s'"),
 825                                prefix_len,
 826                                prefix ? prefix : "",
 827                                prefix ? "/" : "", path);
 828        }
 829        return buf.st_dev;
 830}
 831
 832/*
 833 * A "string_list_each_func_t" function that canonicalizes an entry
 834 * from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or
 835 * discards it if unusable.  The presence of an empty entry in
 836 * GIT_CEILING_DIRECTORIES turns off canonicalization for all
 837 * subsequent entries.
 838 */
 839static int canonicalize_ceiling_entry(struct string_list_item *item,
 840                                      void *cb_data)
 841{
 842        int *empty_entry_found = cb_data;
 843        char *ceil = item->string;
 844
 845        if (!*ceil) {
 846                *empty_entry_found = 1;
 847                return 0;
 848        } else if (!is_absolute_path(ceil)) {
 849                return 0;
 850        } else if (*empty_entry_found) {
 851                /* Keep entry but do not canonicalize it */
 852                return 1;
 853        } else {
 854                char *real_path = real_pathdup(ceil, 0);
 855                if (!real_path) {
 856                        return 0;
 857                }
 858                free(item->string);
 859                item->string = real_path;
 860                return 1;
 861        }
 862}
 863
 864enum discovery_result {
 865        GIT_DIR_NONE = 0,
 866        GIT_DIR_EXPLICIT,
 867        GIT_DIR_DISCOVERED,
 868        GIT_DIR_BARE,
 869        /* these are errors */
 870        GIT_DIR_HIT_CEILING = -1,
 871        GIT_DIR_HIT_MOUNT_POINT = -2,
 872        GIT_DIR_INVALID_GITFILE = -3
 873};
 874
 875/*
 876 * We cannot decide in this function whether we are in the work tree or
 877 * not, since the config can only be read _after_ this function was called.
 878 *
 879 * Also, we avoid changing any global state (such as the current working
 880 * directory) to allow early callers.
 881 *
 882 * The directory where the search should start needs to be passed in via the
 883 * `dir` parameter; upon return, the `dir` buffer will contain the path of
 884 * the directory where the search ended, and `gitdir` will contain the path of
 885 * the discovered .git/ directory, if any. If `gitdir` is not absolute, it
 886 * is relative to `dir` (i.e. *not* necessarily the cwd).
 887 */
 888static enum discovery_result setup_git_directory_gently_1(struct strbuf *dir,
 889                                                          struct strbuf *gitdir,
 890                                                          int die_on_error)
 891{
 892        const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 893        struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
 894        const char *gitdirenv;
 895        int ceil_offset = -1, min_offset = has_dos_drive_prefix(dir->buf) ? 3 : 1;
 896        dev_t current_device = 0;
 897        int one_filesystem = 1;
 898
 899        /*
 900         * If GIT_DIR is set explicitly, we're not going
 901         * to do any discovery, but we still do repository
 902         * validation.
 903         */
 904        gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 905        if (gitdirenv) {
 906                strbuf_addstr(gitdir, gitdirenv);
 907                return GIT_DIR_EXPLICIT;
 908        }
 909
 910        if (env_ceiling_dirs) {
 911                int empty_entry_found = 0;
 912
 913                string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
 914                filter_string_list(&ceiling_dirs, 0,
 915                                   canonicalize_ceiling_entry, &empty_entry_found);
 916                ceil_offset = longest_ancestor_length(dir->buf, &ceiling_dirs);
 917                string_list_clear(&ceiling_dirs, 0);
 918        }
 919
 920        if (ceil_offset < 0)
 921                ceil_offset = min_offset - 2;
 922
 923        /*
 924         * Test in the following order (relative to the dir):
 925         * - .git (file containing "gitdir: <path>")
 926         * - .git/
 927         * - ./ (bare)
 928         * - ../.git
 929         * - ../.git/
 930         * - ../ (bare)
 931         * - ../../.git
 932         *   etc.
 933         */
 934        one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
 935        if (one_filesystem)
 936                current_device = get_device_or_die(dir->buf, NULL, 0);
 937        for (;;) {
 938                int offset = dir->len, error_code = 0;
 939
 940                if (offset > min_offset)
 941                        strbuf_addch(dir, '/');
 942                strbuf_addstr(dir, DEFAULT_GIT_DIR_ENVIRONMENT);
 943                gitdirenv = read_gitfile_gently(dir->buf, die_on_error ?
 944                                                NULL : &error_code);
 945                if (!gitdirenv) {
 946                        if (die_on_error ||
 947                            error_code == READ_GITFILE_ERR_NOT_A_FILE) {
 948                                /* NEEDSWORK: fail if .git is not file nor dir */
 949                                if (is_git_directory(dir->buf))
 950                                        gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
 951                        } else if (error_code != READ_GITFILE_ERR_STAT_FAILED)
 952                                return GIT_DIR_INVALID_GITFILE;
 953                }
 954                strbuf_setlen(dir, offset);
 955                if (gitdirenv) {
 956                        strbuf_addstr(gitdir, gitdirenv);
 957                        return GIT_DIR_DISCOVERED;
 958                }
 959
 960                if (is_git_directory(dir->buf)) {
 961                        strbuf_addstr(gitdir, ".");
 962                        return GIT_DIR_BARE;
 963                }
 964
 965                if (offset <= min_offset)
 966                        return GIT_DIR_HIT_CEILING;
 967
 968                while (--offset > ceil_offset && !is_dir_sep(dir->buf[offset]))
 969                        ; /* continue */
 970                if (offset <= ceil_offset)
 971                        return GIT_DIR_HIT_CEILING;
 972
 973                strbuf_setlen(dir, offset > min_offset ?  offset : min_offset);
 974                if (one_filesystem &&
 975                    current_device != get_device_or_die(dir->buf, NULL, offset))
 976                        return GIT_DIR_HIT_MOUNT_POINT;
 977        }
 978}
 979
 980int discover_git_directory(struct strbuf *commondir,
 981                           struct strbuf *gitdir)
 982{
 983        struct strbuf dir = STRBUF_INIT, err = STRBUF_INIT;
 984        size_t gitdir_offset = gitdir->len, cwd_len;
 985        size_t commondir_offset = commondir->len;
 986        struct repository_format candidate;
 987
 988        if (strbuf_getcwd(&dir))
 989                return -1;
 990
 991        cwd_len = dir.len;
 992        if (setup_git_directory_gently_1(&dir, gitdir, 0) <= 0) {
 993                strbuf_release(&dir);
 994                return -1;
 995        }
 996
 997        /*
 998         * The returned gitdir is relative to dir, and if dir does not reflect
 999         * the current working directory, we simply make the gitdir absolute.
1000         */
1001        if (dir.len < cwd_len && !is_absolute_path(gitdir->buf + gitdir_offset)) {
1002                /* Avoid a trailing "/." */
1003                if (!strcmp(".", gitdir->buf + gitdir_offset))
1004                        strbuf_setlen(gitdir, gitdir_offset);
1005                else
1006                        strbuf_addch(&dir, '/');
1007                strbuf_insert(gitdir, gitdir_offset, dir.buf, dir.len);
1008        }
1009
1010        get_common_dir(commondir, gitdir->buf + gitdir_offset);
1011
1012        strbuf_reset(&dir);
1013        strbuf_addf(&dir, "%s/config", commondir->buf + commondir_offset);
1014        read_repository_format(&candidate, dir.buf);
1015        strbuf_release(&dir);
1016
1017        if (verify_repository_format(&candidate, &err) < 0) {
1018                warning("ignoring git dir '%s': %s",
1019                        gitdir->buf + gitdir_offset, err.buf);
1020                strbuf_release(&err);
1021                strbuf_setlen(commondir, commondir_offset);
1022                strbuf_setlen(gitdir, gitdir_offset);
1023                return -1;
1024        }
1025
1026        return 0;
1027}
1028
1029const char *setup_git_directory_gently(int *nongit_ok)
1030{
1031        static struct strbuf cwd = STRBUF_INIT;
1032        struct strbuf dir = STRBUF_INIT, gitdir = STRBUF_INIT;
1033        const char *prefix;
1034        struct repository_format repo_fmt;
1035
1036        /*
1037         * We may have read an incomplete configuration before
1038         * setting-up the git directory. If so, clear the cache so
1039         * that the next queries to the configuration reload complete
1040         * configuration (including the per-repo config file that we
1041         * ignored previously).
1042         */
1043        git_config_clear();
1044
1045        /*
1046         * Let's assume that we are in a git repository.
1047         * If it turns out later that we are somewhere else, the value will be
1048         * updated accordingly.
1049         */
1050        if (nongit_ok)
1051                *nongit_ok = 0;
1052
1053        if (strbuf_getcwd(&cwd))
1054                die_errno(_("Unable to read current working directory"));
1055        strbuf_addbuf(&dir, &cwd);
1056
1057        switch (setup_git_directory_gently_1(&dir, &gitdir, 1)) {
1058        case GIT_DIR_NONE:
1059                prefix = NULL;
1060                break;
1061        case GIT_DIR_EXPLICIT:
1062                prefix = setup_explicit_git_dir(gitdir.buf, &cwd, &repo_fmt, nongit_ok);
1063                break;
1064        case GIT_DIR_DISCOVERED:
1065                if (dir.len < cwd.len && chdir(dir.buf))
1066                        die(_("cannot change to '%s'"), dir.buf);
1067                prefix = setup_discovered_git_dir(gitdir.buf, &cwd, dir.len,
1068                                                  &repo_fmt, nongit_ok);
1069                break;
1070        case GIT_DIR_BARE:
1071                if (dir.len < cwd.len && chdir(dir.buf))
1072                        die(_("cannot change to '%s'"), dir.buf);
1073                prefix = setup_bare_git_dir(&cwd, dir.len, &repo_fmt, nongit_ok);
1074                break;
1075        case GIT_DIR_HIT_CEILING:
1076                prefix = setup_nongit(cwd.buf, nongit_ok);
1077                break;
1078        case GIT_DIR_HIT_MOUNT_POINT:
1079                if (nongit_ok) {
1080                        *nongit_ok = 1;
1081                        strbuf_release(&cwd);
1082                        strbuf_release(&dir);
1083                        return NULL;
1084                }
1085                die(_("not a git repository (or any parent up to mount point %s)\n"
1086                      "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set)."),
1087                    dir.buf);
1088        default:
1089                die("BUG: unhandled setup_git_directory_1() result");
1090        }
1091
1092        if (prefix)
1093                setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
1094        else
1095                setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
1096
1097        startup_info->have_repository = !nongit_ok || !*nongit_ok;
1098        startup_info->prefix = prefix;
1099
1100        /*
1101         * Not all paths through the setup code will call 'set_git_dir()' (which
1102         * directly sets up the environment) so in order to guarantee that the
1103         * environment is in a consistent state after setup, explicitly setup
1104         * the environment if we have a repository.
1105         *
1106         * NEEDSWORK: currently we allow bogus GIT_DIR values to be set in some
1107         * code paths so we also need to explicitly setup the environment if
1108         * the user has set GIT_DIR.  It may be beneficial to disallow bogus
1109         * GIT_DIR values at some point in the future.
1110         */
1111        if (startup_info->have_repository || getenv(GIT_DIR_ENVIRONMENT)) {
1112                if (!the_repository->gitdir) {
1113                        const char *gitdir = getenv(GIT_DIR_ENVIRONMENT);
1114                        if (!gitdir)
1115                                gitdir = DEFAULT_GIT_DIR_ENVIRONMENT;
1116                        setup_git_env(gitdir);
1117                }
1118                if (startup_info->have_repository)
1119                        repo_set_hash_algo(the_repository, repo_fmt.hash_algo);
1120        }
1121
1122        strbuf_release(&dir);
1123        strbuf_release(&gitdir);
1124
1125        return prefix;
1126}
1127
1128int git_config_perm(const char *var, const char *value)
1129{
1130        int i;
1131        char *endptr;
1132
1133        if (value == NULL)
1134                return PERM_GROUP;
1135
1136        if (!strcmp(value, "umask"))
1137                return PERM_UMASK;
1138        if (!strcmp(value, "group"))
1139                return PERM_GROUP;
1140        if (!strcmp(value, "all") ||
1141            !strcmp(value, "world") ||
1142            !strcmp(value, "everybody"))
1143                return PERM_EVERYBODY;
1144
1145        /* Parse octal numbers */
1146        i = strtol(value, &endptr, 8);
1147
1148        /* If not an octal number, maybe true/false? */
1149        if (*endptr != 0)
1150                return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
1151
1152        /*
1153         * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
1154         * a chmod value to restrict to.
1155         */
1156        switch (i) {
1157        case PERM_UMASK:               /* 0 */
1158                return PERM_UMASK;
1159        case OLD_PERM_GROUP:           /* 1 */
1160                return PERM_GROUP;
1161        case OLD_PERM_EVERYBODY:       /* 2 */
1162                return PERM_EVERYBODY;
1163        }
1164
1165        /* A filemode value was given: 0xxx */
1166
1167        if ((i & 0600) != 0600)
1168                die(_("problem with core.sharedRepository filemode value "
1169                    "(0%.3o).\nThe owner of files must always have "
1170                    "read and write permissions."), i);
1171
1172        /*
1173         * Mask filemode value. Others can not get write permission.
1174         * x flags for directories are handled separately.
1175         */
1176        return -(i & 0666);
1177}
1178
1179void check_repository_format(void)
1180{
1181        struct repository_format repo_fmt;
1182        check_repository_format_gently(get_git_dir(), &repo_fmt, NULL);
1183        startup_info->have_repository = 1;
1184}
1185
1186/*
1187 * Returns the "prefix", a path to the current working directory
1188 * relative to the work tree root, or NULL, if the current working
1189 * directory is not a strict subdirectory of the work tree root. The
1190 * prefix always ends with a '/' character.
1191 */
1192const char *setup_git_directory(void)
1193{
1194        return setup_git_directory_gently(NULL);
1195}
1196
1197const char *resolve_gitdir_gently(const char *suspect, int *return_error_code)
1198{
1199        if (is_git_directory(suspect))
1200                return suspect;
1201        return read_gitfile_gently(suspect, return_error_code);
1202}
1203
1204/* if any standard file descriptor is missing open it to /dev/null */
1205void sanitize_stdfds(void)
1206{
1207        int fd = open("/dev/null", O_RDWR, 0);
1208        while (fd != -1 && fd < 2)
1209                fd = dup(fd);
1210        if (fd == -1)
1211                die_errno(_("open /dev/null or dup failed"));
1212        if (fd > 2)
1213                close(fd);
1214}
1215
1216int daemonize(void)
1217{
1218#ifdef NO_POSIX_GOODIES
1219        errno = ENOSYS;
1220        return -1;
1221#else
1222        switch (fork()) {
1223                case 0:
1224                        break;
1225                case -1:
1226                        die_errno(_("fork failed"));
1227                default:
1228                        exit(0);
1229        }
1230        if (setsid() == -1)
1231                die_errno(_("setsid failed"));
1232        close(0);
1233        close(1);
1234        close(2);
1235        sanitize_stdfds();
1236        return 0;
1237#endif
1238}