setup.con commit worktree: introduce "add" command (fc56361)
   1#include "cache.h"
   2#include "dir.h"
   3#include "string-list.h"
   4
   5static int inside_git_dir = -1;
   6static int inside_work_tree = -1;
   7
   8/*
   9 * The input parameter must contain an absolute path, and it must already be
  10 * normalized.
  11 *
  12 * Find the part of an absolute path that lies inside the work tree by
  13 * dereferencing symlinks outside the work tree, for example:
  14 * /dir1/repo/dir2/file   (work tree is /dir1/repo)      -> dir2/file
  15 * /dir/file              (work tree is /)               -> dir/file
  16 * /dir/symlink1/symlink2 (symlink1 points to work tree) -> symlink2
  17 * /dir/repolink/file     (repolink points to /dir/repo) -> file
  18 * /dir/repo              (exactly equal to work tree)   -> (empty string)
  19 */
  20static int abspath_part_inside_repo(char *path)
  21{
  22        size_t len;
  23        size_t wtlen;
  24        char *path0;
  25        int off;
  26        const char *work_tree = get_git_work_tree();
  27
  28        if (!work_tree)
  29                return -1;
  30        wtlen = strlen(work_tree);
  31        len = strlen(path);
  32        off = offset_1st_component(path);
  33
  34        /* check if work tree is already the prefix */
  35        if (wtlen <= len && !strncmp(path, work_tree, wtlen)) {
  36                if (path[wtlen] == '/') {
  37                        memmove(path, path + wtlen + 1, len - wtlen);
  38                        return 0;
  39                } else if (path[wtlen - 1] == '/' || path[wtlen] == '\0') {
  40                        /* work tree is the root, or the whole path */
  41                        memmove(path, path + wtlen, len - wtlen + 1);
  42                        return 0;
  43                }
  44                /* work tree might match beginning of a symlink to work tree */
  45                off = wtlen;
  46        }
  47        path0 = path;
  48        path += off;
  49
  50        /* check each '/'-terminated level */
  51        while (*path) {
  52                path++;
  53                if (*path == '/') {
  54                        *path = '\0';
  55                        if (strcmp(real_path(path0), work_tree) == 0) {
  56                                memmove(path0, path + 1, len - (path - path0));
  57                                return 0;
  58                        }
  59                        *path = '/';
  60                }
  61        }
  62
  63        /* check whole path */
  64        if (strcmp(real_path(path0), work_tree) == 0) {
  65                *path0 = '\0';
  66                return 0;
  67        }
  68
  69        return -1;
  70}
  71
  72/*
  73 * Normalize "path", prepending the "prefix" for relative paths. If
  74 * remaining_prefix is not NULL, return the actual prefix still
  75 * remains in the path. For example, prefix = sub1/sub2/ and path is
  76 *
  77 *  foo          -> sub1/sub2/foo  (full prefix)
  78 *  ../foo       -> sub1/foo       (remaining prefix is sub1/)
  79 *  ../../bar    -> bar            (no remaining prefix)
  80 *  ../../sub1/sub2/foo -> sub1/sub2/foo (but no remaining prefix)
  81 *  `pwd`/../bar -> sub1/bar       (no remaining prefix)
  82 */
  83char *prefix_path_gently(const char *prefix, int len,
  84                         int *remaining_prefix, const char *path)
  85{
  86        const char *orig = path;
  87        char *sanitized;
  88        if (is_absolute_path(orig)) {
  89                sanitized = xmalloc(strlen(path) + 1);
  90                if (remaining_prefix)
  91                        *remaining_prefix = 0;
  92                if (normalize_path_copy_len(sanitized, path, remaining_prefix)) {
  93                        free(sanitized);
  94                        return NULL;
  95                }
  96                if (abspath_part_inside_repo(sanitized)) {
  97                        free(sanitized);
  98                        return NULL;
  99                }
 100        } else {
 101                sanitized = xmalloc(len + strlen(path) + 1);
 102                if (len)
 103                        memcpy(sanitized, prefix, len);
 104                strcpy(sanitized + len, path);
 105                if (remaining_prefix)
 106                        *remaining_prefix = len;
 107                if (normalize_path_copy_len(sanitized, sanitized, remaining_prefix)) {
 108                        free(sanitized);
 109                        return NULL;
 110                }
 111        }
 112        return sanitized;
 113}
 114
 115char *prefix_path(const char *prefix, int len, const char *path)
 116{
 117        char *r = prefix_path_gently(prefix, len, NULL, path);
 118        if (!r)
 119                die("'%s' is outside repository", path);
 120        return r;
 121}
 122
 123int path_inside_repo(const char *prefix, const char *path)
 124{
 125        int len = prefix ? strlen(prefix) : 0;
 126        char *r = prefix_path_gently(prefix, len, NULL, path);
 127        if (r) {
 128                free(r);
 129                return 1;
 130        }
 131        return 0;
 132}
 133
 134int check_filename(const char *prefix, const char *arg)
 135{
 136        const char *name;
 137        struct stat st;
 138
 139        if (starts_with(arg, ":/")) {
 140                if (arg[2] == '\0') /* ":/" is root dir, always exists */
 141                        return 1;
 142                name = arg + 2;
 143        } else if (prefix)
 144                name = prefix_filename(prefix, strlen(prefix), arg);
 145        else
 146                name = arg;
 147        if (!lstat(name, &st))
 148                return 1; /* file exists */
 149        if (errno == ENOENT || errno == ENOTDIR)
 150                return 0; /* file does not exist */
 151        die_errno("failed to stat '%s'", arg);
 152}
 153
 154static void NORETURN die_verify_filename(const char *prefix,
 155                                         const char *arg,
 156                                         int diagnose_misspelt_rev)
 157{
 158        if (!diagnose_misspelt_rev)
 159                die("%s: no such path in the working tree.\n"
 160                    "Use 'git <command> -- <path>...' to specify paths that do not exist locally.",
 161                    arg);
 162        /*
 163         * Saying "'(icase)foo' does not exist in the index" when the
 164         * user gave us ":(icase)foo" is just stupid.  A magic pathspec
 165         * begins with a colon and is followed by a non-alnum; do not
 166         * let maybe_die_on_misspelt_object_name() even trigger.
 167         */
 168        if (!(arg[0] == ':' && !isalnum(arg[1])))
 169                maybe_die_on_misspelt_object_name(arg, prefix);
 170
 171        /* ... or fall back the most general message. */
 172        die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
 173            "Use '--' to separate paths from revisions, like this:\n"
 174            "'git <command> [<revision>...] -- [<file>...]'", arg);
 175
 176}
 177
 178/*
 179 * Verify a filename that we got as an argument for a pathspec
 180 * entry. Note that a filename that begins with "-" never verifies
 181 * as true, because even if such a filename were to exist, we want
 182 * it to be preceded by the "--" marker (or we want the user to
 183 * use a format like "./-filename")
 184 *
 185 * The "diagnose_misspelt_rev" is used to provide a user-friendly
 186 * diagnosis when dying upon finding that "name" is not a pathname.
 187 * If set to 1, the diagnosis will try to diagnose "name" as an
 188 * invalid object name (e.g. HEAD:foo). If set to 0, the diagnosis
 189 * will only complain about an inexisting file.
 190 *
 191 * This function is typically called to check that a "file or rev"
 192 * argument is unambiguous. In this case, the caller will want
 193 * diagnose_misspelt_rev == 1 when verifying the first non-rev
 194 * argument (which could have been a revision), and
 195 * diagnose_misspelt_rev == 0 for the next ones (because we already
 196 * saw a filename, there's not ambiguity anymore).
 197 */
 198void verify_filename(const char *prefix,
 199                     const char *arg,
 200                     int diagnose_misspelt_rev)
 201{
 202        if (*arg == '-')
 203                die("bad flag '%s' used after filename", arg);
 204        if (check_filename(prefix, arg))
 205                return;
 206        die_verify_filename(prefix, arg, diagnose_misspelt_rev);
 207}
 208
 209/*
 210 * Opposite of the above: the command line did not have -- marker
 211 * and we parsed the arg as a refname.  It should not be interpretable
 212 * as a filename.
 213 */
 214void verify_non_filename(const char *prefix, const char *arg)
 215{
 216        if (!is_inside_work_tree() || is_inside_git_dir())
 217                return;
 218        if (*arg == '-')
 219                return; /* flag */
 220        if (!check_filename(prefix, arg))
 221                return;
 222        die("ambiguous argument '%s': both revision and filename\n"
 223            "Use '--' to separate paths from revisions, like this:\n"
 224            "'git <command> [<revision>...] -- [<file>...]'", arg);
 225}
 226
 227int get_common_dir(struct strbuf *sb, const char *gitdir)
 228{
 229        struct strbuf data = STRBUF_INIT;
 230        struct strbuf path = STRBUF_INIT;
 231        const char *git_common_dir = getenv(GIT_COMMON_DIR_ENVIRONMENT);
 232        int ret = 0;
 233        if (git_common_dir) {
 234                strbuf_addstr(sb, git_common_dir);
 235                return 1;
 236        }
 237        strbuf_addf(&path, "%s/commondir", gitdir);
 238        if (file_exists(path.buf)) {
 239                if (strbuf_read_file(&data, path.buf, 0) <= 0)
 240                        die_errno(_("failed to read %s"), path.buf);
 241                while (data.len && (data.buf[data.len - 1] == '\n' ||
 242                                    data.buf[data.len - 1] == '\r'))
 243                        data.len--;
 244                data.buf[data.len] = '\0';
 245                strbuf_reset(&path);
 246                if (!is_absolute_path(data.buf))
 247                        strbuf_addf(&path, "%s/", gitdir);
 248                strbuf_addbuf(&path, &data);
 249                strbuf_addstr(sb, real_path(path.buf));
 250                ret = 1;
 251        } else
 252                strbuf_addstr(sb, gitdir);
 253        strbuf_release(&data);
 254        strbuf_release(&path);
 255        return ret;
 256}
 257
 258/*
 259 * Test if it looks like we're at a git directory.
 260 * We want to see:
 261 *
 262 *  - either an objects/ directory _or_ the proper
 263 *    GIT_OBJECT_DIRECTORY environment variable
 264 *  - a refs/ directory
 265 *  - either a HEAD symlink or a HEAD file that is formatted as
 266 *    a proper "ref:", or a regular file HEAD that has a properly
 267 *    formatted sha1 object name.
 268 */
 269int is_git_directory(const char *suspect)
 270{
 271        struct strbuf path = STRBUF_INIT;
 272        int ret = 0;
 273        size_t len;
 274
 275        /* Check worktree-related signatures */
 276        strbuf_addf(&path, "%s/HEAD", suspect);
 277        if (validate_headref(path.buf))
 278                goto done;
 279
 280        strbuf_reset(&path);
 281        get_common_dir(&path, suspect);
 282        len = path.len;
 283
 284        /* Check non-worktree-related signatures */
 285        if (getenv(DB_ENVIRONMENT)) {
 286                if (access(getenv(DB_ENVIRONMENT), X_OK))
 287                        goto done;
 288        }
 289        else {
 290                strbuf_setlen(&path, len);
 291                strbuf_addstr(&path, "/objects");
 292                if (access(path.buf, X_OK))
 293                        goto done;
 294        }
 295
 296        strbuf_setlen(&path, len);
 297        strbuf_addstr(&path, "/refs");
 298        if (access(path.buf, X_OK))
 299                goto done;
 300
 301        ret = 1;
 302done:
 303        strbuf_release(&path);
 304        return ret;
 305}
 306
 307int is_inside_git_dir(void)
 308{
 309        if (inside_git_dir < 0)
 310                inside_git_dir = is_inside_dir(get_git_dir());
 311        return inside_git_dir;
 312}
 313
 314int is_inside_work_tree(void)
 315{
 316        if (inside_work_tree < 0)
 317                inside_work_tree = is_inside_dir(get_git_work_tree());
 318        return inside_work_tree;
 319}
 320
 321void setup_work_tree(void)
 322{
 323        const char *work_tree, *git_dir;
 324        static int initialized = 0;
 325
 326        if (initialized)
 327                return;
 328        work_tree = get_git_work_tree();
 329        git_dir = get_git_dir();
 330        if (!is_absolute_path(git_dir))
 331                git_dir = real_path(get_git_dir());
 332        if (!work_tree || chdir(work_tree))
 333                die("This operation must be run in a work tree");
 334
 335        /*
 336         * Make sure subsequent git processes find correct worktree
 337         * if $GIT_WORK_TREE is set relative
 338         */
 339        if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 340                setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 341
 342        set_git_dir(remove_leading_path(git_dir, work_tree));
 343        initialized = 1;
 344}
 345
 346static int check_repo_format(const char *var, const char *value, void *cb)
 347{
 348        if (strcmp(var, "core.repositoryformatversion") == 0)
 349                repository_format_version = git_config_int(var, value);
 350        else if (strcmp(var, "core.sharedrepository") == 0)
 351                shared_repository = git_config_perm(var, value);
 352        return 0;
 353}
 354
 355static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 356{
 357        struct strbuf sb = STRBUF_INIT;
 358        const char *repo_config;
 359        config_fn_t fn;
 360        int ret = 0;
 361
 362        if (get_common_dir(&sb, gitdir))
 363                fn = check_repo_format;
 364        else
 365                fn = check_repository_format_version;
 366        strbuf_addstr(&sb, "/config");
 367        repo_config = sb.buf;
 368
 369        /*
 370         * git_config() can't be used here because it calls git_pathdup()
 371         * to get $GIT_CONFIG/config. That call will make setup_git_env()
 372         * set git_dir to ".git".
 373         *
 374         * We are in gitdir setup, no git dir has been found useable yet.
 375         * Use a gentler version of git_config() to check if this repo
 376         * is a good one.
 377         */
 378        git_config_early(fn, NULL, repo_config);
 379        if (GIT_REPO_VERSION < repository_format_version) {
 380                if (!nongit_ok)
 381                        die ("Expected git repo version <= %d, found %d",
 382                             GIT_REPO_VERSION, repository_format_version);
 383                warning("Expected git repo version <= %d, found %d",
 384                        GIT_REPO_VERSION, repository_format_version);
 385                warning("Please upgrade Git");
 386                *nongit_ok = -1;
 387                ret = -1;
 388        }
 389        strbuf_release(&sb);
 390        return ret;
 391}
 392
 393static void update_linked_gitdir(const char *gitfile, const char *gitdir)
 394{
 395        struct strbuf path = STRBUF_INIT;
 396        struct stat st;
 397
 398        strbuf_addf(&path, "%s/gitfile", gitdir);
 399        if (stat(path.buf, &st) || st.st_mtime + 24 * 3600 < time(NULL))
 400                write_file(path.buf, 0, "%s\n", gitfile);
 401        strbuf_release(&path);
 402}
 403
 404/*
 405 * Try to read the location of the git directory from the .git file,
 406 * return path to git directory if found.
 407 */
 408const char *read_gitfile(const char *path)
 409{
 410        char *buf;
 411        char *dir;
 412        const char *slash;
 413        struct stat st;
 414        int fd;
 415        ssize_t len;
 416
 417        if (stat(path, &st))
 418                return NULL;
 419        if (!S_ISREG(st.st_mode))
 420                return NULL;
 421        fd = open(path, O_RDONLY);
 422        if (fd < 0)
 423                die_errno("Error opening '%s'", path);
 424        buf = xmalloc(st.st_size + 1);
 425        len = read_in_full(fd, buf, st.st_size);
 426        close(fd);
 427        if (len != st.st_size)
 428                die("Error reading %s", path);
 429        buf[len] = '\0';
 430        if (!starts_with(buf, "gitdir: "))
 431                die("Invalid gitfile format: %s", path);
 432        while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 433                len--;
 434        if (len < 9)
 435                die("No path in gitfile: %s", path);
 436        buf[len] = '\0';
 437        dir = buf + 8;
 438
 439        if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
 440                size_t pathlen = slash+1 - path;
 441                size_t dirlen = pathlen + len - 8;
 442                dir = xmalloc(dirlen + 1);
 443                strncpy(dir, path, pathlen);
 444                strncpy(dir + pathlen, buf + 8, len - 8);
 445                dir[dirlen] = '\0';
 446                free(buf);
 447                buf = dir;
 448        }
 449
 450        if (!is_git_directory(dir))
 451                die("Not a git repository: %s", dir);
 452
 453        update_linked_gitdir(path, dir);
 454        path = real_path(dir);
 455
 456        free(buf);
 457        return path;
 458}
 459
 460static const char *setup_explicit_git_dir(const char *gitdirenv,
 461                                          struct strbuf *cwd,
 462                                          int *nongit_ok)
 463{
 464        const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 465        const char *worktree;
 466        char *gitfile;
 467        int offset;
 468
 469        if (PATH_MAX - 40 < strlen(gitdirenv))
 470                die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 471
 472        gitfile = (char*)read_gitfile(gitdirenv);
 473        if (gitfile) {
 474                gitfile = xstrdup(gitfile);
 475                gitdirenv = gitfile;
 476        }
 477
 478        if (!is_git_directory(gitdirenv)) {
 479                if (nongit_ok) {
 480                        *nongit_ok = 1;
 481                        free(gitfile);
 482                        return NULL;
 483                }
 484                die("Not a git repository: '%s'", gitdirenv);
 485        }
 486
 487        if (check_repository_format_gently(gitdirenv, nongit_ok)) {
 488                free(gitfile);
 489                return NULL;
 490        }
 491
 492        /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
 493        if (work_tree_env)
 494                set_git_work_tree(work_tree_env);
 495        else if (is_bare_repository_cfg > 0) {
 496                if (git_work_tree_cfg) /* #22.2, #30 */
 497                        die("core.bare and core.worktree do not make sense");
 498
 499                /* #18, #26 */
 500                set_git_dir(gitdirenv);
 501                free(gitfile);
 502                return NULL;
 503        }
 504        else if (git_work_tree_cfg) { /* #6, #14 */
 505                if (is_absolute_path(git_work_tree_cfg))
 506                        set_git_work_tree(git_work_tree_cfg);
 507                else {
 508                        char *core_worktree;
 509                        if (chdir(gitdirenv))
 510                                die_errno("Could not chdir to '%s'", gitdirenv);
 511                        if (chdir(git_work_tree_cfg))
 512                                die_errno("Could not chdir to '%s'", git_work_tree_cfg);
 513                        core_worktree = xgetcwd();
 514                        if (chdir(cwd->buf))
 515                                die_errno("Could not come back to cwd");
 516                        set_git_work_tree(core_worktree);
 517                        free(core_worktree);
 518                }
 519        }
 520        else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
 521                /* #16d */
 522                set_git_dir(gitdirenv);
 523                free(gitfile);
 524                return NULL;
 525        }
 526        else /* #2, #10 */
 527                set_git_work_tree(".");
 528
 529        /* set_git_work_tree() must have been called by now */
 530        worktree = get_git_work_tree();
 531
 532        /* both get_git_work_tree() and cwd are already normalized */
 533        if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */
 534                set_git_dir(gitdirenv);
 535                free(gitfile);
 536                return NULL;
 537        }
 538
 539        offset = dir_inside_of(cwd->buf, worktree);
 540        if (offset >= 0) {      /* cwd inside worktree? */
 541                set_git_dir(real_path(gitdirenv));
 542                if (chdir(worktree))
 543                        die_errno("Could not chdir to '%s'", worktree);
 544                strbuf_addch(cwd, '/');
 545                free(gitfile);
 546                return cwd->buf + offset;
 547        }
 548
 549        /* cwd outside worktree */
 550        set_git_dir(gitdirenv);
 551        free(gitfile);
 552        return NULL;
 553}
 554
 555static const char *setup_discovered_git_dir(const char *gitdir,
 556                                            struct strbuf *cwd, int offset,
 557                                            int *nongit_ok)
 558{
 559        if (check_repository_format_gently(gitdir, nongit_ok))
 560                return NULL;
 561
 562        /* --work-tree is set without --git-dir; use discovered one */
 563        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 564                if (offset != cwd->len && !is_absolute_path(gitdir))
 565                        gitdir = xstrdup(real_path(gitdir));
 566                if (chdir(cwd->buf))
 567                        die_errno("Could not come back to cwd");
 568                return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 569        }
 570
 571        /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 572        if (is_bare_repository_cfg > 0) {
 573                set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir));
 574                if (chdir(cwd->buf))
 575                        die_errno("Could not come back to cwd");
 576                return NULL;
 577        }
 578
 579        /* #0, #1, #5, #8, #9, #12, #13 */
 580        set_git_work_tree(".");
 581        if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
 582                set_git_dir(gitdir);
 583        inside_git_dir = 0;
 584        inside_work_tree = 1;
 585        if (offset == cwd->len)
 586                return NULL;
 587
 588        /* Make "offset" point to past the '/', and add a '/' at the end */
 589        offset++;
 590        strbuf_addch(cwd, '/');
 591        return cwd->buf + offset;
 592}
 593
 594/* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
 595static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
 596                                      int *nongit_ok)
 597{
 598        int root_len;
 599
 600        if (check_repository_format_gently(".", nongit_ok))
 601                return NULL;
 602
 603        setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 604
 605        /* --work-tree is set without --git-dir; use discovered one */
 606        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 607                const char *gitdir;
 608
 609                gitdir = offset == cwd->len ? "." : xmemdupz(cwd->buf, offset);
 610                if (chdir(cwd->buf))
 611                        die_errno("Could not come back to cwd");
 612                return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 613        }
 614
 615        inside_git_dir = 1;
 616        inside_work_tree = 0;
 617        if (offset != cwd->len) {
 618                if (chdir(cwd->buf))
 619                        die_errno("Cannot come back to cwd");
 620                root_len = offset_1st_component(cwd->buf);
 621                strbuf_setlen(cwd, offset > root_len ? offset : root_len);
 622                set_git_dir(cwd->buf);
 623        }
 624        else
 625                set_git_dir(".");
 626        return NULL;
 627}
 628
 629static const char *setup_nongit(const char *cwd, int *nongit_ok)
 630{
 631        if (!nongit_ok)
 632                die("Not a git repository (or any of the parent directories): %s", DEFAULT_GIT_DIR_ENVIRONMENT);
 633        if (chdir(cwd))
 634                die_errno("Cannot come back to cwd");
 635        *nongit_ok = 1;
 636        return NULL;
 637}
 638
 639static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
 640{
 641        struct stat buf;
 642        if (stat(path, &buf)) {
 643                die_errno("failed to stat '%*s%s%s'",
 644                                prefix_len,
 645                                prefix ? prefix : "",
 646                                prefix ? "/" : "", path);
 647        }
 648        return buf.st_dev;
 649}
 650
 651/*
 652 * A "string_list_each_func_t" function that canonicalizes an entry
 653 * from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or
 654 * discards it if unusable.  The presence of an empty entry in
 655 * GIT_CEILING_DIRECTORIES turns off canonicalization for all
 656 * subsequent entries.
 657 */
 658static int canonicalize_ceiling_entry(struct string_list_item *item,
 659                                      void *cb_data)
 660{
 661        int *empty_entry_found = cb_data;
 662        char *ceil = item->string;
 663
 664        if (!*ceil) {
 665                *empty_entry_found = 1;
 666                return 0;
 667        } else if (!is_absolute_path(ceil)) {
 668                return 0;
 669        } else if (*empty_entry_found) {
 670                /* Keep entry but do not canonicalize it */
 671                return 1;
 672        } else {
 673                const char *real_path = real_path_if_valid(ceil);
 674                if (!real_path)
 675                        return 0;
 676                free(item->string);
 677                item->string = xstrdup(real_path);
 678                return 1;
 679        }
 680}
 681
 682/*
 683 * We cannot decide in this function whether we are in the work tree or
 684 * not, since the config can only be read _after_ this function was called.
 685 */
 686static const char *setup_git_directory_gently_1(int *nongit_ok)
 687{
 688        const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 689        struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
 690        static struct strbuf cwd = STRBUF_INIT;
 691        const char *gitdirenv, *ret;
 692        char *gitfile;
 693        int offset, offset_parent, ceil_offset = -1;
 694        dev_t current_device = 0;
 695        int one_filesystem = 1;
 696
 697        /*
 698         * We may have read an incomplete configuration before
 699         * setting-up the git directory. If so, clear the cache so
 700         * that the next queries to the configuration reload complete
 701         * configuration (including the per-repo config file that we
 702         * ignored previously).
 703         */
 704        git_config_clear();
 705
 706        /*
 707         * Let's assume that we are in a git repository.
 708         * If it turns out later that we are somewhere else, the value will be
 709         * updated accordingly.
 710         */
 711        if (nongit_ok)
 712                *nongit_ok = 0;
 713
 714        if (strbuf_getcwd(&cwd))
 715                die_errno("Unable to read current working directory");
 716        offset = cwd.len;
 717
 718        /*
 719         * If GIT_DIR is set explicitly, we're not going
 720         * to do any discovery, but we still do repository
 721         * validation.
 722         */
 723        gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 724        if (gitdirenv)
 725                return setup_explicit_git_dir(gitdirenv, &cwd, nongit_ok);
 726
 727        if (env_ceiling_dirs) {
 728                int empty_entry_found = 0;
 729
 730                string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
 731                filter_string_list(&ceiling_dirs, 0,
 732                                   canonicalize_ceiling_entry, &empty_entry_found);
 733                ceil_offset = longest_ancestor_length(cwd.buf, &ceiling_dirs);
 734                string_list_clear(&ceiling_dirs, 0);
 735        }
 736
 737        if (ceil_offset < 0 && has_dos_drive_prefix(cwd.buf))
 738                ceil_offset = 1;
 739
 740        /*
 741         * Test in the following order (relative to the cwd):
 742         * - .git (file containing "gitdir: <path>")
 743         * - .git/
 744         * - ./ (bare)
 745         * - ../.git
 746         * - ../.git/
 747         * - ../ (bare)
 748         * - ../../.git/
 749         *   etc.
 750         */
 751        one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
 752        if (one_filesystem)
 753                current_device = get_device_or_die(".", NULL, 0);
 754        for (;;) {
 755                gitfile = (char*)read_gitfile(DEFAULT_GIT_DIR_ENVIRONMENT);
 756                if (gitfile)
 757                        gitdirenv = gitfile = xstrdup(gitfile);
 758                else {
 759                        if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 760                                gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
 761                }
 762
 763                if (gitdirenv) {
 764                        ret = setup_discovered_git_dir(gitdirenv,
 765                                                       &cwd, offset,
 766                                                       nongit_ok);
 767                        free(gitfile);
 768                        return ret;
 769                }
 770                free(gitfile);
 771
 772                if (is_git_directory("."))
 773                        return setup_bare_git_dir(&cwd, offset, nongit_ok);
 774
 775                offset_parent = offset;
 776                while (--offset_parent > ceil_offset && cwd.buf[offset_parent] != '/');
 777                if (offset_parent <= ceil_offset)
 778                        return setup_nongit(cwd.buf, nongit_ok);
 779                if (one_filesystem) {
 780                        dev_t parent_device = get_device_or_die("..", cwd.buf,
 781                                                                offset);
 782                        if (parent_device != current_device) {
 783                                if (nongit_ok) {
 784                                        if (chdir(cwd.buf))
 785                                                die_errno("Cannot come back to cwd");
 786                                        *nongit_ok = 1;
 787                                        return NULL;
 788                                }
 789                                strbuf_setlen(&cwd, offset);
 790                                die("Not a git repository (or any parent up to mount point %s)\n"
 791                                "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).",
 792                                    cwd.buf);
 793                        }
 794                }
 795                if (chdir("..")) {
 796                        strbuf_setlen(&cwd, offset);
 797                        die_errno("Cannot change to '%s/..'", cwd.buf);
 798                }
 799                offset = offset_parent;
 800        }
 801}
 802
 803const char *setup_git_directory_gently(int *nongit_ok)
 804{
 805        const char *prefix;
 806
 807        prefix = setup_git_directory_gently_1(nongit_ok);
 808        if (prefix)
 809                setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
 810        else
 811                setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
 812
 813        if (startup_info) {
 814                startup_info->have_repository = !nongit_ok || !*nongit_ok;
 815                startup_info->prefix = prefix;
 816        }
 817        return prefix;
 818}
 819
 820int git_config_perm(const char *var, const char *value)
 821{
 822        int i;
 823        char *endptr;
 824
 825        if (value == NULL)
 826                return PERM_GROUP;
 827
 828        if (!strcmp(value, "umask"))
 829                return PERM_UMASK;
 830        if (!strcmp(value, "group"))
 831                return PERM_GROUP;
 832        if (!strcmp(value, "all") ||
 833            !strcmp(value, "world") ||
 834            !strcmp(value, "everybody"))
 835                return PERM_EVERYBODY;
 836
 837        /* Parse octal numbers */
 838        i = strtol(value, &endptr, 8);
 839
 840        /* If not an octal number, maybe true/false? */
 841        if (*endptr != 0)
 842                return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
 843
 844        /*
 845         * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
 846         * a chmod value to restrict to.
 847         */
 848        switch (i) {
 849        case PERM_UMASK:               /* 0 */
 850                return PERM_UMASK;
 851        case OLD_PERM_GROUP:           /* 1 */
 852                return PERM_GROUP;
 853        case OLD_PERM_EVERYBODY:       /* 2 */
 854                return PERM_EVERYBODY;
 855        }
 856
 857        /* A filemode value was given: 0xxx */
 858
 859        if ((i & 0600) != 0600)
 860                die("Problem with core.sharedRepository filemode value "
 861                    "(0%.3o).\nThe owner of files must always have "
 862                    "read and write permissions.", i);
 863
 864        /*
 865         * Mask filemode value. Others can not get write permission.
 866         * x flags for directories are handled separately.
 867         */
 868        return -(i & 0666);
 869}
 870
 871int check_repository_format_version(const char *var, const char *value, void *cb)
 872{
 873        int ret = check_repo_format(var, value, cb);
 874        if (ret)
 875                return ret;
 876        if (strcmp(var, "core.bare") == 0) {
 877                is_bare_repository_cfg = git_config_bool(var, value);
 878                if (is_bare_repository_cfg == 1)
 879                        inside_work_tree = -1;
 880        } else if (strcmp(var, "core.worktree") == 0) {
 881                if (!value)
 882                        return config_error_nonbool(var);
 883                free(git_work_tree_cfg);
 884                git_work_tree_cfg = xstrdup(value);
 885                inside_work_tree = -1;
 886        }
 887        return 0;
 888}
 889
 890int check_repository_format(void)
 891{
 892        return check_repository_format_gently(get_git_dir(), NULL);
 893}
 894
 895/*
 896 * Returns the "prefix", a path to the current working directory
 897 * relative to the work tree root, or NULL, if the current working
 898 * directory is not a strict subdirectory of the work tree root. The
 899 * prefix always ends with a '/' character.
 900 */
 901const char *setup_git_directory(void)
 902{
 903        return setup_git_directory_gently(NULL);
 904}
 905
 906const char *resolve_gitdir(const char *suspect)
 907{
 908        if (is_git_directory(suspect))
 909                return suspect;
 910        return read_gitfile(suspect);
 911}
 912
 913/* if any standard file descriptor is missing open it to /dev/null */
 914void sanitize_stdfds(void)
 915{
 916        int fd = open("/dev/null", O_RDWR, 0);
 917        while (fd != -1 && fd < 2)
 918                fd = dup(fd);
 919        if (fd == -1)
 920                die_errno("open /dev/null or dup failed");
 921        if (fd > 2)
 922                close(fd);
 923}
 924
 925int daemonize(void)
 926{
 927#ifdef NO_POSIX_GOODIES
 928        errno = ENOSYS;
 929        return -1;
 930#else
 931        switch (fork()) {
 932                case 0:
 933                        break;
 934                case -1:
 935                        die_errno("fork failed");
 936                default:
 937                        exit(0);
 938        }
 939        if (setsid() == -1)
 940                die_errno("setsid failed");
 941        close(0);
 942        close(1);
 943        close(2);
 944        sanitize_stdfds();
 945        return 0;
 946#endif
 947}