setup.con commit Merge branch 'jc/diff-ws-error-highlight' (abecdde)
   1#include "cache.h"
   2#include "dir.h"
   3#include "string-list.h"
   4
   5static int inside_git_dir = -1;
   6static int inside_work_tree = -1;
   7static int work_tree_config_is_bogus;
   8
   9/*
  10 * The input parameter must contain an absolute path, and it must already be
  11 * normalized.
  12 *
  13 * Find the part of an absolute path that lies inside the work tree by
  14 * dereferencing symlinks outside the work tree, for example:
  15 * /dir1/repo/dir2/file   (work tree is /dir1/repo)      -> dir2/file
  16 * /dir/file              (work tree is /)               -> dir/file
  17 * /dir/symlink1/symlink2 (symlink1 points to work tree) -> symlink2
  18 * /dir/repolink/file     (repolink points to /dir/repo) -> file
  19 * /dir/repo              (exactly equal to work tree)   -> (empty string)
  20 */
  21static int abspath_part_inside_repo(char *path)
  22{
  23        size_t len;
  24        size_t wtlen;
  25        char *path0;
  26        int off;
  27        const char *work_tree = get_git_work_tree();
  28
  29        if (!work_tree)
  30                return -1;
  31        wtlen = strlen(work_tree);
  32        len = strlen(path);
  33        off = offset_1st_component(path);
  34
  35        /* check if work tree is already the prefix */
  36        if (wtlen <= len && !strncmp(path, work_tree, wtlen)) {
  37                if (path[wtlen] == '/') {
  38                        memmove(path, path + wtlen + 1, len - wtlen);
  39                        return 0;
  40                } else if (path[wtlen - 1] == '/' || path[wtlen] == '\0') {
  41                        /* work tree is the root, or the whole path */
  42                        memmove(path, path + wtlen, len - wtlen + 1);
  43                        return 0;
  44                }
  45                /* work tree might match beginning of a symlink to work tree */
  46                off = wtlen;
  47        }
  48        path0 = path;
  49        path += off;
  50
  51        /* check each '/'-terminated level */
  52        while (*path) {
  53                path++;
  54                if (*path == '/') {
  55                        *path = '\0';
  56                        if (strcmp(real_path(path0), work_tree) == 0) {
  57                                memmove(path0, path + 1, len - (path - path0));
  58                                return 0;
  59                        }
  60                        *path = '/';
  61                }
  62        }
  63
  64        /* check whole path */
  65        if (strcmp(real_path(path0), work_tree) == 0) {
  66                *path0 = '\0';
  67                return 0;
  68        }
  69
  70        return -1;
  71}
  72
  73/*
  74 * Normalize "path", prepending the "prefix" for relative paths. If
  75 * remaining_prefix is not NULL, return the actual prefix still
  76 * remains in the path. For example, prefix = sub1/sub2/ and path is
  77 *
  78 *  foo          -> sub1/sub2/foo  (full prefix)
  79 *  ../foo       -> sub1/foo       (remaining prefix is sub1/)
  80 *  ../../bar    -> bar            (no remaining prefix)
  81 *  ../../sub1/sub2/foo -> sub1/sub2/foo (but no remaining prefix)
  82 *  `pwd`/../bar -> sub1/bar       (no remaining prefix)
  83 */
  84char *prefix_path_gently(const char *prefix, int len,
  85                         int *remaining_prefix, const char *path)
  86{
  87        const char *orig = path;
  88        char *sanitized;
  89        if (is_absolute_path(orig)) {
  90                sanitized = xmalloc(strlen(path) + 1);
  91                if (remaining_prefix)
  92                        *remaining_prefix = 0;
  93                if (normalize_path_copy_len(sanitized, path, remaining_prefix)) {
  94                        free(sanitized);
  95                        return NULL;
  96                }
  97                if (abspath_part_inside_repo(sanitized)) {
  98                        free(sanitized);
  99                        return NULL;
 100                }
 101        } else {
 102                sanitized = xmalloc(len + strlen(path) + 1);
 103                if (len)
 104                        memcpy(sanitized, prefix, len);
 105                strcpy(sanitized + len, path);
 106                if (remaining_prefix)
 107                        *remaining_prefix = len;
 108                if (normalize_path_copy_len(sanitized, sanitized, remaining_prefix)) {
 109                        free(sanitized);
 110                        return NULL;
 111                }
 112        }
 113        return sanitized;
 114}
 115
 116char *prefix_path(const char *prefix, int len, const char *path)
 117{
 118        char *r = prefix_path_gently(prefix, len, NULL, path);
 119        if (!r)
 120                die("'%s' is outside repository", path);
 121        return r;
 122}
 123
 124int path_inside_repo(const char *prefix, const char *path)
 125{
 126        int len = prefix ? strlen(prefix) : 0;
 127        char *r = prefix_path_gently(prefix, len, NULL, path);
 128        if (r) {
 129                free(r);
 130                return 1;
 131        }
 132        return 0;
 133}
 134
 135int check_filename(const char *prefix, const char *arg)
 136{
 137        const char *name;
 138        struct stat st;
 139
 140        if (starts_with(arg, ":/")) {
 141                if (arg[2] == '\0') /* ":/" is root dir, always exists */
 142                        return 1;
 143                name = arg + 2;
 144        } else if (!no_wildcard(arg))
 145                return 1;
 146        else if (prefix)
 147                name = prefix_filename(prefix, strlen(prefix), arg);
 148        else
 149                name = arg;
 150        if (!lstat(name, &st))
 151                return 1; /* file exists */
 152        if (errno == ENOENT || errno == ENOTDIR)
 153                return 0; /* file does not exist */
 154        die_errno("failed to stat '%s'", arg);
 155}
 156
 157static void NORETURN die_verify_filename(const char *prefix,
 158                                         const char *arg,
 159                                         int diagnose_misspelt_rev)
 160{
 161        if (!diagnose_misspelt_rev)
 162                die("%s: no such path in the working tree.\n"
 163                    "Use 'git <command> -- <path>...' to specify paths that do not exist locally.",
 164                    arg);
 165        /*
 166         * Saying "'(icase)foo' does not exist in the index" when the
 167         * user gave us ":(icase)foo" is just stupid.  A magic pathspec
 168         * begins with a colon and is followed by a non-alnum; do not
 169         * let maybe_die_on_misspelt_object_name() even trigger.
 170         */
 171        if (!(arg[0] == ':' && !isalnum(arg[1])))
 172                maybe_die_on_misspelt_object_name(arg, prefix);
 173
 174        /* ... or fall back the most general message. */
 175        die("ambiguous argument '%s': unknown revision or path not in the working tree.\n"
 176            "Use '--' to separate paths from revisions, like this:\n"
 177            "'git <command> [<revision>...] -- [<file>...]'", arg);
 178
 179}
 180
 181/*
 182 * Verify a filename that we got as an argument for a pathspec
 183 * entry. Note that a filename that begins with "-" never verifies
 184 * as true, because even if such a filename were to exist, we want
 185 * it to be preceded by the "--" marker (or we want the user to
 186 * use a format like "./-filename")
 187 *
 188 * The "diagnose_misspelt_rev" is used to provide a user-friendly
 189 * diagnosis when dying upon finding that "name" is not a pathname.
 190 * If set to 1, the diagnosis will try to diagnose "name" as an
 191 * invalid object name (e.g. HEAD:foo). If set to 0, the diagnosis
 192 * will only complain about an inexisting file.
 193 *
 194 * This function is typically called to check that a "file or rev"
 195 * argument is unambiguous. In this case, the caller will want
 196 * diagnose_misspelt_rev == 1 when verifying the first non-rev
 197 * argument (which could have been a revision), and
 198 * diagnose_misspelt_rev == 0 for the next ones (because we already
 199 * saw a filename, there's not ambiguity anymore).
 200 */
 201void verify_filename(const char *prefix,
 202                     const char *arg,
 203                     int diagnose_misspelt_rev)
 204{
 205        if (*arg == '-')
 206                die("bad flag '%s' used after filename", arg);
 207        if (check_filename(prefix, arg))
 208                return;
 209        die_verify_filename(prefix, arg, diagnose_misspelt_rev);
 210}
 211
 212/*
 213 * Opposite of the above: the command line did not have -- marker
 214 * and we parsed the arg as a refname.  It should not be interpretable
 215 * as a filename.
 216 */
 217void verify_non_filename(const char *prefix, const char *arg)
 218{
 219        if (!is_inside_work_tree() || is_inside_git_dir())
 220                return;
 221        if (*arg == '-')
 222                return; /* flag */
 223        if (!check_filename(prefix, arg))
 224                return;
 225        die("ambiguous argument '%s': both revision and filename\n"
 226            "Use '--' to separate paths from revisions, like this:\n"
 227            "'git <command> [<revision>...] -- [<file>...]'", arg);
 228}
 229
 230int get_common_dir(struct strbuf *sb, const char *gitdir)
 231{
 232        struct strbuf data = STRBUF_INIT;
 233        struct strbuf path = STRBUF_INIT;
 234        const char *git_common_dir = getenv(GIT_COMMON_DIR_ENVIRONMENT);
 235        int ret = 0;
 236        if (git_common_dir) {
 237                strbuf_addstr(sb, git_common_dir);
 238                return 1;
 239        }
 240        strbuf_addf(&path, "%s/commondir", gitdir);
 241        if (file_exists(path.buf)) {
 242                if (strbuf_read_file(&data, path.buf, 0) <= 0)
 243                        die_errno(_("failed to read %s"), path.buf);
 244                while (data.len && (data.buf[data.len - 1] == '\n' ||
 245                                    data.buf[data.len - 1] == '\r'))
 246                        data.len--;
 247                data.buf[data.len] = '\0';
 248                strbuf_reset(&path);
 249                if (!is_absolute_path(data.buf))
 250                        strbuf_addf(&path, "%s/", gitdir);
 251                strbuf_addbuf(&path, &data);
 252                strbuf_addstr(sb, real_path(path.buf));
 253                ret = 1;
 254        } else
 255                strbuf_addstr(sb, gitdir);
 256        strbuf_release(&data);
 257        strbuf_release(&path);
 258        return ret;
 259}
 260
 261/*
 262 * Test if it looks like we're at a git directory.
 263 * We want to see:
 264 *
 265 *  - either an objects/ directory _or_ the proper
 266 *    GIT_OBJECT_DIRECTORY environment variable
 267 *  - a refs/ directory
 268 *  - either a HEAD symlink or a HEAD file that is formatted as
 269 *    a proper "ref:", or a regular file HEAD that has a properly
 270 *    formatted sha1 object name.
 271 */
 272int is_git_directory(const char *suspect)
 273{
 274        struct strbuf path = STRBUF_INIT;
 275        int ret = 0;
 276        size_t len;
 277
 278        /* Check worktree-related signatures */
 279        strbuf_addf(&path, "%s/HEAD", suspect);
 280        if (validate_headref(path.buf))
 281                goto done;
 282
 283        strbuf_reset(&path);
 284        get_common_dir(&path, suspect);
 285        len = path.len;
 286
 287        /* Check non-worktree-related signatures */
 288        if (getenv(DB_ENVIRONMENT)) {
 289                if (access(getenv(DB_ENVIRONMENT), X_OK))
 290                        goto done;
 291        }
 292        else {
 293                strbuf_setlen(&path, len);
 294                strbuf_addstr(&path, "/objects");
 295                if (access(path.buf, X_OK))
 296                        goto done;
 297        }
 298
 299        strbuf_setlen(&path, len);
 300        strbuf_addstr(&path, "/refs");
 301        if (access(path.buf, X_OK))
 302                goto done;
 303
 304        ret = 1;
 305done:
 306        strbuf_release(&path);
 307        return ret;
 308}
 309
 310int is_inside_git_dir(void)
 311{
 312        if (inside_git_dir < 0)
 313                inside_git_dir = is_inside_dir(get_git_dir());
 314        return inside_git_dir;
 315}
 316
 317int is_inside_work_tree(void)
 318{
 319        if (inside_work_tree < 0)
 320                inside_work_tree = is_inside_dir(get_git_work_tree());
 321        return inside_work_tree;
 322}
 323
 324void setup_work_tree(void)
 325{
 326        const char *work_tree, *git_dir;
 327        static int initialized = 0;
 328
 329        if (initialized)
 330                return;
 331
 332        if (work_tree_config_is_bogus)
 333                die("unable to set up work tree using invalid config");
 334
 335        work_tree = get_git_work_tree();
 336        git_dir = get_git_dir();
 337        if (!is_absolute_path(git_dir))
 338                git_dir = real_path(get_git_dir());
 339        if (!work_tree || chdir(work_tree))
 340                die("This operation must be run in a work tree");
 341
 342        /*
 343         * Make sure subsequent git processes find correct worktree
 344         * if $GIT_WORK_TREE is set relative
 345         */
 346        if (getenv(GIT_WORK_TREE_ENVIRONMENT))
 347                setenv(GIT_WORK_TREE_ENVIRONMENT, ".", 1);
 348
 349        set_git_dir(remove_leading_path(git_dir, work_tree));
 350        initialized = 1;
 351}
 352
 353static int check_repo_format(const char *var, const char *value, void *cb)
 354{
 355        if (strcmp(var, "core.repositoryformatversion") == 0)
 356                repository_format_version = git_config_int(var, value);
 357        else if (strcmp(var, "core.sharedrepository") == 0)
 358                shared_repository = git_config_perm(var, value);
 359        return 0;
 360}
 361
 362static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 363{
 364        struct strbuf sb = STRBUF_INIT;
 365        const char *repo_config;
 366        config_fn_t fn;
 367        int ret = 0;
 368
 369        if (get_common_dir(&sb, gitdir))
 370                fn = check_repo_format;
 371        else
 372                fn = check_repository_format_version;
 373        strbuf_addstr(&sb, "/config");
 374        repo_config = sb.buf;
 375
 376        /*
 377         * git_config() can't be used here because it calls git_pathdup()
 378         * to get $GIT_CONFIG/config. That call will make setup_git_env()
 379         * set git_dir to ".git".
 380         *
 381         * We are in gitdir setup, no git dir has been found useable yet.
 382         * Use a gentler version of git_config() to check if this repo
 383         * is a good one.
 384         */
 385        git_config_early(fn, NULL, repo_config);
 386        if (GIT_REPO_VERSION < repository_format_version) {
 387                if (!nongit_ok)
 388                        die ("Expected git repo version <= %d, found %d",
 389                             GIT_REPO_VERSION, repository_format_version);
 390                warning("Expected git repo version <= %d, found %d",
 391                        GIT_REPO_VERSION, repository_format_version);
 392                warning("Please upgrade Git");
 393                *nongit_ok = -1;
 394                ret = -1;
 395        }
 396        strbuf_release(&sb);
 397        return ret;
 398}
 399
 400static void update_linked_gitdir(const char *gitfile, const char *gitdir)
 401{
 402        struct strbuf path = STRBUF_INIT;
 403        struct stat st;
 404
 405        strbuf_addf(&path, "%s/gitfile", gitdir);
 406        if (stat(path.buf, &st) || st.st_mtime + 24 * 3600 < time(NULL))
 407                write_file(path.buf, 0, "%s\n", gitfile);
 408        strbuf_release(&path);
 409}
 410
 411/*
 412 * Try to read the location of the git directory from the .git file,
 413 * return path to git directory if found.
 414 */
 415const char *read_gitfile(const char *path)
 416{
 417        char *buf;
 418        char *dir;
 419        const char *slash;
 420        struct stat st;
 421        int fd;
 422        ssize_t len;
 423
 424        if (stat(path, &st))
 425                return NULL;
 426        if (!S_ISREG(st.st_mode))
 427                return NULL;
 428        fd = open(path, O_RDONLY);
 429        if (fd < 0)
 430                die_errno("Error opening '%s'", path);
 431        buf = xmalloc(st.st_size + 1);
 432        len = read_in_full(fd, buf, st.st_size);
 433        close(fd);
 434        if (len != st.st_size)
 435                die("Error reading %s", path);
 436        buf[len] = '\0';
 437        if (!starts_with(buf, "gitdir: "))
 438                die("Invalid gitfile format: %s", path);
 439        while (buf[len - 1] == '\n' || buf[len - 1] == '\r')
 440                len--;
 441        if (len < 9)
 442                die("No path in gitfile: %s", path);
 443        buf[len] = '\0';
 444        dir = buf + 8;
 445
 446        if (!is_absolute_path(dir) && (slash = strrchr(path, '/'))) {
 447                size_t pathlen = slash+1 - path;
 448                size_t dirlen = pathlen + len - 8;
 449                dir = xmalloc(dirlen + 1);
 450                strncpy(dir, path, pathlen);
 451                strncpy(dir + pathlen, buf + 8, len - 8);
 452                dir[dirlen] = '\0';
 453                free(buf);
 454                buf = dir;
 455        }
 456
 457        if (!is_git_directory(dir))
 458                die("Not a git repository: %s", dir);
 459
 460        update_linked_gitdir(path, dir);
 461        path = real_path(dir);
 462
 463        free(buf);
 464        return path;
 465}
 466
 467static const char *setup_explicit_git_dir(const char *gitdirenv,
 468                                          struct strbuf *cwd,
 469                                          int *nongit_ok)
 470{
 471        const char *work_tree_env = getenv(GIT_WORK_TREE_ENVIRONMENT);
 472        const char *worktree;
 473        char *gitfile;
 474        int offset;
 475
 476        if (PATH_MAX - 40 < strlen(gitdirenv))
 477                die("'$%s' too big", GIT_DIR_ENVIRONMENT);
 478
 479        gitfile = (char*)read_gitfile(gitdirenv);
 480        if (gitfile) {
 481                gitfile = xstrdup(gitfile);
 482                gitdirenv = gitfile;
 483        }
 484
 485        if (!is_git_directory(gitdirenv)) {
 486                if (nongit_ok) {
 487                        *nongit_ok = 1;
 488                        free(gitfile);
 489                        return NULL;
 490                }
 491                die("Not a git repository: '%s'", gitdirenv);
 492        }
 493
 494        if (check_repository_format_gently(gitdirenv, nongit_ok)) {
 495                free(gitfile);
 496                return NULL;
 497        }
 498
 499        /* #3, #7, #11, #15, #19, #23, #27, #31 (see t1510) */
 500        if (work_tree_env)
 501                set_git_work_tree(work_tree_env);
 502        else if (is_bare_repository_cfg > 0) {
 503                if (git_work_tree_cfg) {
 504                        /* #22.2, #30 */
 505                        warning("core.bare and core.worktree do not make sense");
 506                        work_tree_config_is_bogus = 1;
 507                }
 508
 509                /* #18, #26 */
 510                set_git_dir(gitdirenv);
 511                free(gitfile);
 512                return NULL;
 513        }
 514        else if (git_work_tree_cfg) { /* #6, #14 */
 515                if (is_absolute_path(git_work_tree_cfg))
 516                        set_git_work_tree(git_work_tree_cfg);
 517                else {
 518                        char *core_worktree;
 519                        if (chdir(gitdirenv))
 520                                die_errno("Could not chdir to '%s'", gitdirenv);
 521                        if (chdir(git_work_tree_cfg))
 522                                die_errno("Could not chdir to '%s'", git_work_tree_cfg);
 523                        core_worktree = xgetcwd();
 524                        if (chdir(cwd->buf))
 525                                die_errno("Could not come back to cwd");
 526                        set_git_work_tree(core_worktree);
 527                        free(core_worktree);
 528                }
 529        }
 530        else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) {
 531                /* #16d */
 532                set_git_dir(gitdirenv);
 533                free(gitfile);
 534                return NULL;
 535        }
 536        else /* #2, #10 */
 537                set_git_work_tree(".");
 538
 539        /* set_git_work_tree() must have been called by now */
 540        worktree = get_git_work_tree();
 541
 542        /* both get_git_work_tree() and cwd are already normalized */
 543        if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */
 544                set_git_dir(gitdirenv);
 545                free(gitfile);
 546                return NULL;
 547        }
 548
 549        offset = dir_inside_of(cwd->buf, worktree);
 550        if (offset >= 0) {      /* cwd inside worktree? */
 551                set_git_dir(real_path(gitdirenv));
 552                if (chdir(worktree))
 553                        die_errno("Could not chdir to '%s'", worktree);
 554                strbuf_addch(cwd, '/');
 555                free(gitfile);
 556                return cwd->buf + offset;
 557        }
 558
 559        /* cwd outside worktree */
 560        set_git_dir(gitdirenv);
 561        free(gitfile);
 562        return NULL;
 563}
 564
 565static const char *setup_discovered_git_dir(const char *gitdir,
 566                                            struct strbuf *cwd, int offset,
 567                                            int *nongit_ok)
 568{
 569        if (check_repository_format_gently(gitdir, nongit_ok))
 570                return NULL;
 571
 572        /* --work-tree is set without --git-dir; use discovered one */
 573        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 574                if (offset != cwd->len && !is_absolute_path(gitdir))
 575                        gitdir = xstrdup(real_path(gitdir));
 576                if (chdir(cwd->buf))
 577                        die_errno("Could not come back to cwd");
 578                return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 579        }
 580
 581        /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */
 582        if (is_bare_repository_cfg > 0) {
 583                set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir));
 584                if (chdir(cwd->buf))
 585                        die_errno("Could not come back to cwd");
 586                return NULL;
 587        }
 588
 589        /* #0, #1, #5, #8, #9, #12, #13 */
 590        set_git_work_tree(".");
 591        if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT))
 592                set_git_dir(gitdir);
 593        inside_git_dir = 0;
 594        inside_work_tree = 1;
 595        if (offset == cwd->len)
 596                return NULL;
 597
 598        /* Make "offset" point to past the '/', and add a '/' at the end */
 599        offset++;
 600        strbuf_addch(cwd, '/');
 601        return cwd->buf + offset;
 602}
 603
 604/* #16.1, #17.1, #20.1, #21.1, #22.1 (see t1510) */
 605static const char *setup_bare_git_dir(struct strbuf *cwd, int offset,
 606                                      int *nongit_ok)
 607{
 608        int root_len;
 609
 610        if (check_repository_format_gently(".", nongit_ok))
 611                return NULL;
 612
 613        setenv(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, "0", 1);
 614
 615        /* --work-tree is set without --git-dir; use discovered one */
 616        if (getenv(GIT_WORK_TREE_ENVIRONMENT) || git_work_tree_cfg) {
 617                const char *gitdir;
 618
 619                gitdir = offset == cwd->len ? "." : xmemdupz(cwd->buf, offset);
 620                if (chdir(cwd->buf))
 621                        die_errno("Could not come back to cwd");
 622                return setup_explicit_git_dir(gitdir, cwd, nongit_ok);
 623        }
 624
 625        inside_git_dir = 1;
 626        inside_work_tree = 0;
 627        if (offset != cwd->len) {
 628                if (chdir(cwd->buf))
 629                        die_errno("Cannot come back to cwd");
 630                root_len = offset_1st_component(cwd->buf);
 631                strbuf_setlen(cwd, offset > root_len ? offset : root_len);
 632                set_git_dir(cwd->buf);
 633        }
 634        else
 635                set_git_dir(".");
 636        return NULL;
 637}
 638
 639static const char *setup_nongit(const char *cwd, int *nongit_ok)
 640{
 641        if (!nongit_ok)
 642                die("Not a git repository (or any of the parent directories): %s", DEFAULT_GIT_DIR_ENVIRONMENT);
 643        if (chdir(cwd))
 644                die_errno("Cannot come back to cwd");
 645        *nongit_ok = 1;
 646        return NULL;
 647}
 648
 649static dev_t get_device_or_die(const char *path, const char *prefix, int prefix_len)
 650{
 651        struct stat buf;
 652        if (stat(path, &buf)) {
 653                die_errno("failed to stat '%*s%s%s'",
 654                                prefix_len,
 655                                prefix ? prefix : "",
 656                                prefix ? "/" : "", path);
 657        }
 658        return buf.st_dev;
 659}
 660
 661/*
 662 * A "string_list_each_func_t" function that canonicalizes an entry
 663 * from GIT_CEILING_DIRECTORIES using real_path_if_valid(), or
 664 * discards it if unusable.  The presence of an empty entry in
 665 * GIT_CEILING_DIRECTORIES turns off canonicalization for all
 666 * subsequent entries.
 667 */
 668static int canonicalize_ceiling_entry(struct string_list_item *item,
 669                                      void *cb_data)
 670{
 671        int *empty_entry_found = cb_data;
 672        char *ceil = item->string;
 673
 674        if (!*ceil) {
 675                *empty_entry_found = 1;
 676                return 0;
 677        } else if (!is_absolute_path(ceil)) {
 678                return 0;
 679        } else if (*empty_entry_found) {
 680                /* Keep entry but do not canonicalize it */
 681                return 1;
 682        } else {
 683                const char *real_path = real_path_if_valid(ceil);
 684                if (!real_path)
 685                        return 0;
 686                free(item->string);
 687                item->string = xstrdup(real_path);
 688                return 1;
 689        }
 690}
 691
 692/*
 693 * We cannot decide in this function whether we are in the work tree or
 694 * not, since the config can only be read _after_ this function was called.
 695 */
 696static const char *setup_git_directory_gently_1(int *nongit_ok)
 697{
 698        const char *env_ceiling_dirs = getenv(CEILING_DIRECTORIES_ENVIRONMENT);
 699        struct string_list ceiling_dirs = STRING_LIST_INIT_DUP;
 700        static struct strbuf cwd = STRBUF_INIT;
 701        const char *gitdirenv, *ret;
 702        char *gitfile;
 703        int offset, offset_parent, ceil_offset = -1;
 704        dev_t current_device = 0;
 705        int one_filesystem = 1;
 706
 707        /*
 708         * We may have read an incomplete configuration before
 709         * setting-up the git directory. If so, clear the cache so
 710         * that the next queries to the configuration reload complete
 711         * configuration (including the per-repo config file that we
 712         * ignored previously).
 713         */
 714        git_config_clear();
 715
 716        /*
 717         * Let's assume that we are in a git repository.
 718         * If it turns out later that we are somewhere else, the value will be
 719         * updated accordingly.
 720         */
 721        if (nongit_ok)
 722                *nongit_ok = 0;
 723
 724        if (strbuf_getcwd(&cwd))
 725                die_errno("Unable to read current working directory");
 726        offset = cwd.len;
 727
 728        /*
 729         * If GIT_DIR is set explicitly, we're not going
 730         * to do any discovery, but we still do repository
 731         * validation.
 732         */
 733        gitdirenv = getenv(GIT_DIR_ENVIRONMENT);
 734        if (gitdirenv)
 735                return setup_explicit_git_dir(gitdirenv, &cwd, nongit_ok);
 736
 737        if (env_ceiling_dirs) {
 738                int empty_entry_found = 0;
 739
 740                string_list_split(&ceiling_dirs, env_ceiling_dirs, PATH_SEP, -1);
 741                filter_string_list(&ceiling_dirs, 0,
 742                                   canonicalize_ceiling_entry, &empty_entry_found);
 743                ceil_offset = longest_ancestor_length(cwd.buf, &ceiling_dirs);
 744                string_list_clear(&ceiling_dirs, 0);
 745        }
 746
 747        if (ceil_offset < 0 && has_dos_drive_prefix(cwd.buf))
 748                ceil_offset = 1;
 749
 750        /*
 751         * Test in the following order (relative to the cwd):
 752         * - .git (file containing "gitdir: <path>")
 753         * - .git/
 754         * - ./ (bare)
 755         * - ../.git
 756         * - ../.git/
 757         * - ../ (bare)
 758         * - ../../.git/
 759         *   etc.
 760         */
 761        one_filesystem = !git_env_bool("GIT_DISCOVERY_ACROSS_FILESYSTEM", 0);
 762        if (one_filesystem)
 763                current_device = get_device_or_die(".", NULL, 0);
 764        for (;;) {
 765                gitfile = (char*)read_gitfile(DEFAULT_GIT_DIR_ENVIRONMENT);
 766                if (gitfile)
 767                        gitdirenv = gitfile = xstrdup(gitfile);
 768                else {
 769                        if (is_git_directory(DEFAULT_GIT_DIR_ENVIRONMENT))
 770                                gitdirenv = DEFAULT_GIT_DIR_ENVIRONMENT;
 771                }
 772
 773                if (gitdirenv) {
 774                        ret = setup_discovered_git_dir(gitdirenv,
 775                                                       &cwd, offset,
 776                                                       nongit_ok);
 777                        free(gitfile);
 778                        return ret;
 779                }
 780                free(gitfile);
 781
 782                if (is_git_directory("."))
 783                        return setup_bare_git_dir(&cwd, offset, nongit_ok);
 784
 785                offset_parent = offset;
 786                while (--offset_parent > ceil_offset && cwd.buf[offset_parent] != '/');
 787                if (offset_parent <= ceil_offset)
 788                        return setup_nongit(cwd.buf, nongit_ok);
 789                if (one_filesystem) {
 790                        dev_t parent_device = get_device_or_die("..", cwd.buf,
 791                                                                offset);
 792                        if (parent_device != current_device) {
 793                                if (nongit_ok) {
 794                                        if (chdir(cwd.buf))
 795                                                die_errno("Cannot come back to cwd");
 796                                        *nongit_ok = 1;
 797                                        return NULL;
 798                                }
 799                                strbuf_setlen(&cwd, offset);
 800                                die("Not a git repository (or any parent up to mount point %s)\n"
 801                                "Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).",
 802                                    cwd.buf);
 803                        }
 804                }
 805                if (chdir("..")) {
 806                        strbuf_setlen(&cwd, offset);
 807                        die_errno("Cannot change to '%s/..'", cwd.buf);
 808                }
 809                offset = offset_parent;
 810        }
 811}
 812
 813const char *setup_git_directory_gently(int *nongit_ok)
 814{
 815        const char *prefix;
 816
 817        prefix = setup_git_directory_gently_1(nongit_ok);
 818        if (prefix)
 819                setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
 820        else
 821                setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
 822
 823        if (startup_info) {
 824                startup_info->have_repository = !nongit_ok || !*nongit_ok;
 825                startup_info->prefix = prefix;
 826        }
 827        return prefix;
 828}
 829
 830int git_config_perm(const char *var, const char *value)
 831{
 832        int i;
 833        char *endptr;
 834
 835        if (value == NULL)
 836                return PERM_GROUP;
 837
 838        if (!strcmp(value, "umask"))
 839                return PERM_UMASK;
 840        if (!strcmp(value, "group"))
 841                return PERM_GROUP;
 842        if (!strcmp(value, "all") ||
 843            !strcmp(value, "world") ||
 844            !strcmp(value, "everybody"))
 845                return PERM_EVERYBODY;
 846
 847        /* Parse octal numbers */
 848        i = strtol(value, &endptr, 8);
 849
 850        /* If not an octal number, maybe true/false? */
 851        if (*endptr != 0)
 852                return git_config_bool(var, value) ? PERM_GROUP : PERM_UMASK;
 853
 854        /*
 855         * Treat values 0, 1 and 2 as compatibility cases, otherwise it is
 856         * a chmod value to restrict to.
 857         */
 858        switch (i) {
 859        case PERM_UMASK:               /* 0 */
 860                return PERM_UMASK;
 861        case OLD_PERM_GROUP:           /* 1 */
 862                return PERM_GROUP;
 863        case OLD_PERM_EVERYBODY:       /* 2 */
 864                return PERM_EVERYBODY;
 865        }
 866
 867        /* A filemode value was given: 0xxx */
 868
 869        if ((i & 0600) != 0600)
 870                die("Problem with core.sharedRepository filemode value "
 871                    "(0%.3o).\nThe owner of files must always have "
 872                    "read and write permissions.", i);
 873
 874        /*
 875         * Mask filemode value. Others can not get write permission.
 876         * x flags for directories are handled separately.
 877         */
 878        return -(i & 0666);
 879}
 880
 881int check_repository_format_version(const char *var, const char *value, void *cb)
 882{
 883        int ret = check_repo_format(var, value, cb);
 884        if (ret)
 885                return ret;
 886        if (strcmp(var, "core.bare") == 0) {
 887                is_bare_repository_cfg = git_config_bool(var, value);
 888                if (is_bare_repository_cfg == 1)
 889                        inside_work_tree = -1;
 890        } else if (strcmp(var, "core.worktree") == 0) {
 891                if (!value)
 892                        return config_error_nonbool(var);
 893                free(git_work_tree_cfg);
 894                git_work_tree_cfg = xstrdup(value);
 895                inside_work_tree = -1;
 896        }
 897        return 0;
 898}
 899
 900int check_repository_format(void)
 901{
 902        return check_repository_format_gently(get_git_dir(), NULL);
 903}
 904
 905/*
 906 * Returns the "prefix", a path to the current working directory
 907 * relative to the work tree root, or NULL, if the current working
 908 * directory is not a strict subdirectory of the work tree root. The
 909 * prefix always ends with a '/' character.
 910 */
 911const char *setup_git_directory(void)
 912{
 913        return setup_git_directory_gently(NULL);
 914}
 915
 916const char *resolve_gitdir(const char *suspect)
 917{
 918        if (is_git_directory(suspect))
 919                return suspect;
 920        return read_gitfile(suspect);
 921}
 922
 923/* if any standard file descriptor is missing open it to /dev/null */
 924void sanitize_stdfds(void)
 925{
 926        int fd = open("/dev/null", O_RDWR, 0);
 927        while (fd != -1 && fd < 2)
 928                fd = dup(fd);
 929        if (fd == -1)
 930                die_errno("open /dev/null or dup failed");
 931        if (fd > 2)
 932                close(fd);
 933}
 934
 935int daemonize(void)
 936{
 937#ifdef NO_POSIX_GOODIES
 938        errno = ENOSYS;
 939        return -1;
 940#else
 941        switch (fork()) {
 942                case 0:
 943                        break;
 944                case -1:
 945                        die_errno("fork failed");
 946                default:
 947                        exit(0);
 948        }
 949        if (setsid() == -1)
 950                die_errno("setsid failed");
 951        close(0);
 952        close(1);
 953        close(2);
 954        sanitize_stdfds();
 955        return 0;
 956#endif
 957}