builtin/init-db.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6 #include "cache.h"
   7 #include "config.h"
   8 #include "gettext.h"
   9 #include "refs.h"
  10 #include "builtin.h"
  11 #include "exec-cmd.h"
  12 #include "parse-options.h"
  13 #include "worktree.h"
  14
  15 #ifndef DEFAULT_GIT_TEMPLATE_DIR
  16 #define DEFAULT_GIT_TEMPLATE_DIR "/usr/share/git-core/templates"
  17 #endif
  18
  19 #ifdef NO_TRUSTABLE_FILEMODE
  20 #define TEST_FILEMODE 0
  21 #else
  22 #define TEST_FILEMODE 1
  23 #endif
  24
  25 #define GIT_DEFAULT_HASH_ENVIRONMENT "GIT_DEFAULT_HASH"
  26
  27 static int init_is_bare_repository = 0;
  28 static int init_shared_repository = -1;
  29
  30 static void copy_templates_1(struct strbuf *path, struct strbuf *template_path,
  31                              DIR *dir)
  32 {
  33         size_t path_baselen = path->len;
  34         size_t template_baselen = template_path->len;
  35         struct dirent *de;
  36
  37         /* Note: if ".git/hooks" file exists in the repository being
  38          * re-initialized, /etc/core-git/templates/hooks/update would
  39          * cause "git init" to fail here.  I think this is sane but
  40          * it means that the set of templates we ship by default, along
  41          * with the way the namespace under .git/ is organized, should
  42          * be really carefully chosen.
  43          */
  44         safe_create_dir(path->buf, 1);
  45         while ((de = readdir(dir)) != NULL) {
  46                 struct stat st_git, st_template;
  47                 int exists = 0;
  48
  49                 strbuf_setlen(path, path_baselen);
  50                 strbuf_setlen(template_path, template_baselen);
  51
  52                 if (de->d_name[0] == '.')
  53                         continue;
  54                 strbuf_addstr(path, de->d_name);
  55                 strbuf_addstr(template_path, de->d_name);
  56                 if (lstat(path->buf, &st_git)) {
  57                         if (errno != ENOENT)
  58                                 die_errno(_("cannot stat '%s'"), path->buf);
  59                 }
  60                 else
  61                         exists = 1;
  62
  63                 if (lstat(template_path->buf, &st_template))
  64                         die_errno(_("cannot stat template '%s'"), template_path->buf);
  65
  66                 if (S_ISDIR(st_template.st_mode)) {
  67                         DIR *subdir = opendir(template_path->buf);
  68                         if (!subdir)
  69                                 die_errno(_("cannot opendir '%s'"), template_path->buf);
  70                         strbuf_addch(path, '/');
  71                         strbuf_addch(template_path, '/');
  72                         copy_templates_1(path, template_path, subdir);
  73                         closedir(subdir);
  74                 }
  75                 else if (exists)
  76                         continue;
  77                 else if (S_ISLNK(st_template.st_mode)) {
  78                         struct strbuf lnk = STRBUF_INIT;
  79                         if (strbuf_readlink(&lnk, template_path->buf,
  80                                             st_template.st_size) < 0)
  81                                 die_errno(_("cannot readlink '%s'"), template_path->buf);
  82                         if (symlink(lnk.buf, path->buf))
  83                                 die_errno(_("cannot symlink '%s' '%s'"),
  84                                           lnk.buf, path->buf);
  85                         strbuf_release(&lnk);
  86                 }
  87                 else if (S_ISREG(st_template.st_mode)) {
  88                         if (copy_file(path->buf, template_path->buf, st_template.st_mode))
  89                                 die_errno(_("cannot copy '%s' to '%s'"),
  90                                           template_path->buf, path->buf);
  91                 }
  92                 else
  93                         error(_("ignoring template %s"), template_path->buf);
  94         }
  95 }
  96
  97 static void copy_templates(const char *template_dir, const char *init_template_dir)
  98 {
  99         struct strbuf path = STRBUF_INIT;
 100         struct strbuf template_path = STRBUF_INIT;
 101         size_t template_len;
 102         struct repository_format template_format = REPOSITORY_FORMAT_INIT;
 103         struct strbuf err = STRBUF_INIT;
 104         DIR *dir;
 105         char *to_free = NULL;
 106
 107         if (!template_dir)
 108                 template_dir = getenv(TEMPLATE_DIR_ENVIRONMENT);
 109         if (!template_dir)
 110                 template_dir = init_template_dir;
 111         if (!template_dir)
 112                 template_dir = to_free = system_path(DEFAULT_GIT_TEMPLATE_DIR);
 113         if (!template_dir[0]) {
 114                 free(to_free);
 115                 return;
 116         }
 117
 118         strbuf_addstr(&template_path, template_dir);
 119         strbuf_complete(&template_path, '/');
 120         template_len = template_path.len;
 121
 122         dir = opendir(template_path.buf);
 123         if (!dir) {
 124                 warning(_("templates not found in %s"), template_dir);
 125                 goto free_return;
 126         }
 127
 128         /* Make sure that template is from the correct vintage */
 129         strbuf_addstr(&template_path, "config");
 130         read_repository_format(&template_format, template_path.buf);
 131         strbuf_setlen(&template_path, template_len);
 132
 133         /*
 134          * No mention of version at all is OK, but anything else should be
 135          * verified.
 136          */
 137         if (template_format.version >= 0 &&
 138             verify_repository_format(&template_format, &err) < 0) {
 139                 warning(_("not copying templates from '%s': %s"),
 140                           template_dir, err.buf);
 141                 strbuf_release(&err);
 142                 goto close_free_return;
 143         }
 144
 145         strbuf_addstr(&path, get_git_common_dir());
 146         strbuf_complete(&path, '/');
 147         copy_templates_1(&path, &template_path, dir);
 148 close_free_return:
 149         closedir(dir);
 150 free_return:
 151         free(to_free);
 152         strbuf_release(&path);
 153         strbuf_release(&template_path);
 154         clear_repository_format(&template_format);
 155 }
 156
 157 /*
 158  * If the git_dir is not directly inside the working tree, then git will not
 159  * find it by default, and we need to set the worktree explicitly.
 160  */
 161 static int needs_work_tree_config(const char *git_dir, const char *work_tree)
 162 {
 163         if (!strcmp(work_tree, "/") && !strcmp(git_dir, "/.git"))
 164                 return 0;
 165         if (skip_prefix(git_dir, work_tree, &git_dir) &&
 166             !strcmp(git_dir, "/.git"))
 167                 return 0;
 168         return 1;
 169 }
 170
 171 void initialize_repository_version(int hash_algo, int reinit)
 172 {
 173         char repo_version_string[10];
 174         int repo_version = GIT_REPO_VERSION;
 175
 176         if (hash_algo != GIT_HASH_SHA1)
 177                 repo_version = GIT_REPO_VERSION_READ;
 178
 179         /* This forces creation of new config file */
 180         xsnprintf(repo_version_string, sizeof(repo_version_string),
 181                   "%d", repo_version);
 182         git_config_set("core.repositoryformatversion", repo_version_string);
 183
 184         if (hash_algo != GIT_HASH_SHA1)
 185                 git_config_set("extensions.objectformat",
 186                                hash_algos[hash_algo].name);
 187         else if (reinit)
 188                 git_config_set_gently("extensions.objectformat", NULL);
 189 }
 190
 191 static int create_default_files(const char *template_path,
 192                                 const char *original_git_dir,
 193                                 const char *initial_branch,
 194                                 const struct repository_format *fmt,
 195                                 int quiet)
 196 {
 197         struct stat st1;
 198         struct strbuf buf = STRBUF_INIT;
 199         char *path;
 200         char junk[2];
 201         int reinit;
 202         int filemode;
 203         struct strbuf err = STRBUF_INIT;
 204         const char *init_template_dir = NULL;
 205         const char *work_tree = get_git_work_tree();
 206
 207         /*
 208          * First copy the templates -- we might have the default
 209          * config file there, in which case we would want to read
 210          * from it after installing.
 211          *
 212          * Before reading that config, we also need to clear out any cached
 213          * values (since we've just potentially changed what's available on
 214          * disk).
 215          */
 216         git_config_get_pathname("init.templatedir", &init_template_dir);
 217         copy_templates(template_path, init_template_dir);
 218         free((char *)init_template_dir);
 219         git_config_clear();
 220         reset_shared_repository();
 221         git_config(git_default_config, NULL);
 222
 223         /*
 224          * We must make sure command-line options continue to override any
 225          * values we might have just re-read from the config.
 226          */
 227         is_bare_repository_cfg = init_is_bare_repository || !work_tree;
 228         if (init_shared_repository != -1)
 229                 set_shared_repository(init_shared_repository);
 230
 231         /*
 232          * We would have created the above under user's umask -- under
 233          * shared-repository settings, we would need to fix them up.
 234          */
 235         if (get_shared_repository()) {
 236                 adjust_shared_perm(get_git_dir());
 237         }
 238
 239         /*
 240          * We need to create a "refs" dir in any case so that older
 241          * versions of git can tell that this is a repository.
 242          */
 243         safe_create_dir(git_path("refs"), 1);
 244         adjust_shared_perm(git_path("refs"));
 245
 246         if (refs_init_db(&err))
 247                 die("failed to set up refs db: %s", err.buf);
 248
 249         /*
 250          * Point the HEAD symref to the initial branch with if HEAD does
 251          * not yet exist.
 252          */
 253         path = git_path_buf(&buf, "HEAD");
 254         reinit = (!access(path, R_OK)
 255                   || readlink(path, junk, sizeof(junk)-1) != -1);
 256         if (!reinit) {
 257                 char *ref;
 258
 259                 if (!initial_branch)
 260                         initial_branch = git_default_branch_name(quiet);
 261
 262                 ref = xstrfmt("refs/heads/%s", initial_branch);
 263                 if (check_refname_format(ref, 0) < 0)
 264                         die(_("invalid initial branch name: '%s'"),
 265                             initial_branch);
 266
 267                 if (create_symref("HEAD", ref, NULL) < 0)
 268                         exit(1);
 269                 free(ref);
 270         }
 271
 272         initialize_repository_version(fmt->hash_algo, 0);
 273
 274         /* Check filemode trustability */
 275         path = git_path_buf(&buf, "config");
 276         filemode = TEST_FILEMODE;
 277         if (TEST_FILEMODE && !lstat(path, &st1)) {
 278                 struct stat st2;
 279                 filemode = (!chmod(path, st1.st_mode ^ S_IXUSR) &&
 280                                 !lstat(path, &st2) &&
 281                                 st1.st_mode != st2.st_mode &&
 282                                 !chmod(path, st1.st_mode));
 283                 if (filemode && !reinit && (st1.st_mode & S_IXUSR))
 284                         filemode = 0;
 285         }
 286         git_config_set("core.filemode", filemode ? "true" : "false");
 287
 288         if (is_bare_repository())
 289                 git_config_set("core.bare", "true");
 290         else {
 291                 git_config_set("core.bare", "false");
 292                 /* allow template config file to override the default */
 293                 if (log_all_ref_updates == LOG_REFS_UNSET)
 294                         git_config_set("core.logallrefupdates", "true");
 295                 if (needs_work_tree_config(original_git_dir, work_tree))
 296                         git_config_set("core.worktree", work_tree);
 297         }
 298
 299         if (!reinit) {
 300                 /* Check if symlink is supported in the work tree */
 301                 path = git_path_buf(&buf, "tXXXXXX");
 302                 if (!close(xmkstemp(path)) &&
 303                     !unlink(path) &&
 304                     !symlink("testing", path) &&
 305                     !lstat(path, &st1) &&
 306                     S_ISLNK(st1.st_mode))
 307                         unlink(path); /* good */
 308                 else
 309                         git_config_set("core.symlinks", "false");
 310
 311                 /* Check if the filesystem is case-insensitive */
 312                 path = git_path_buf(&buf, "CoNfIg");
 313                 if (!access(path, F_OK))
 314                         git_config_set("core.ignorecase", "true");
 315                 probe_utf8_pathname_composition();
 316         }
 317
 318         strbuf_release(&buf);
 319         return reinit;
 320 }
 321
 322 static void create_object_directory(void)
 323 {
 324         struct strbuf path = STRBUF_INIT;
 325         size_t baselen;
 326
 327         strbuf_addstr(&path, get_object_directory());
 328         baselen = path.len;
 329
 330         safe_create_dir(path.buf, 1);
 331
 332         strbuf_setlen(&path, baselen);
 333         strbuf_addstr(&path, "/pack");
 334         safe_create_dir(path.buf, 1);
 335
 336         strbuf_setlen(&path, baselen);
 337         strbuf_addstr(&path, "/info");
 338         safe_create_dir(path.buf, 1);
 339
 340         strbuf_release(&path);
 341 }
 342
 343 static void separate_git_dir(const char *git_dir, const char *git_link)
 344 {
 345         struct stat st;
 346
 347         if (!stat(git_link, &st)) {
 348                 const char *src;
 349
 350                 if (S_ISREG(st.st_mode))
 351                         src = read_gitfile(git_link);
 352                 else if (S_ISDIR(st.st_mode))
 353                         src = git_link;
 354                 else
 355                         die(_("unable to handle file type %d"), (int)st.st_mode);
 356
 357                 if (rename(src, git_dir))
 358                         die_errno(_("unable to move %s to %s"), src, git_dir);
 359                 repair_worktrees(NULL, NULL);
 360         }
 361
 362         write_file(git_link, "gitdir: %s", git_dir);
 363 }
 364
 365 static void validate_hash_algorithm(struct repository_format *repo_fmt, int hash)
 366 {
 367         const char *env = getenv(GIT_DEFAULT_HASH_ENVIRONMENT);
 368         /*
 369          * If we already have an initialized repo, don't allow the user to
 370          * specify a different algorithm, as that could cause corruption.
 371          * Otherwise, if the user has specified one on the command line, use it.
 372          */
 373         if (repo_fmt->version >= 0 && hash != GIT_HASH_UNKNOWN && hash != repo_fmt->hash_algo)
 374                 die(_("attempt to reinitialize repository with different hash"));
 375         else if (hash != GIT_HASH_UNKNOWN)
 376                 repo_fmt->hash_algo = hash;
 377         else if (env) {
 378                 int env_algo = hash_algo_by_name(env);
 379                 if (env_algo == GIT_HASH_UNKNOWN)
 380                         die(_("unknown hash algorithm '%s'"), env);
 381                 repo_fmt->hash_algo = env_algo;
 382         }
 383 }
 384
 385 int init_db(const char *git_dir, const char *real_git_dir,
 386             const char *template_dir, int hash, const char *initial_branch,
 387             unsigned int flags)
 388 {
 389         int reinit;
 390         int exist_ok = flags & INIT_DB_EXIST_OK;
 391         char *original_git_dir = real_pathdup(git_dir, 1);
 392         struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT;
 393
 394         if (real_git_dir) {
 395                 struct stat st;
 396
 397                 if (!exist_ok && !stat(git_dir, &st))
 398                         die(_("%s already exists"), git_dir);
 399
 400                 if (!exist_ok && !stat(real_git_dir, &st))
 401                         die(_("%s already exists"), real_git_dir);
 402
 403                 set_git_dir(real_git_dir, 1);
 404                 git_dir = get_git_dir();
 405                 separate_git_dir(git_dir, original_git_dir);
 406         }
 407         else {
 408                 set_git_dir(git_dir, 1);
 409                 git_dir = get_git_dir();
 410         }
 411         startup_info->have_repository = 1;
 412
 413         /* Ensure `core.hidedotfiles` is processed */
 414         git_config(platform_core_config, NULL);
 415
 416         safe_create_dir(git_dir, 0);
 417
 418         init_is_bare_repository = is_bare_repository();
 419
 420         /* Check to see if the repository version is right.
 421          * Note that a newly created repository does not have
 422          * config file, so this will not fail.  What we are catching
 423          * is an attempt to reinitialize new repository with an old tool.
 424          */
 425         check_repository_format(&repo_fmt);
 426
 427         validate_hash_algorithm(&repo_fmt, hash);
 428
 429         reinit = create_default_files(template_dir, original_git_dir,
 430                                       initial_branch, &repo_fmt,
 431                                       flags & INIT_DB_QUIET);
 432         if (reinit && initial_branch)
 433                 warning(_("re-init: ignored --initial-branch=%s"),
 434                         initial_branch);
 435
 436         create_object_directory();
 437
 438         if (get_shared_repository()) {
 439                 char buf[10];
 440                 /* We do not spell "group" and such, so that
 441                  * the configuration can be read by older version
 442                  * of git. Note, we use octal numbers for new share modes,
 443                  * and compatibility values for PERM_GROUP and
 444                  * PERM_EVERYBODY.
 445                  */
 446                 if (get_shared_repository() < 0)
 447                         /* force to the mode value */
 448                         xsnprintf(buf, sizeof(buf), "0%o", -get_shared_repository());
 449                 else if (get_shared_repository() == PERM_GROUP)
 450                         xsnprintf(buf, sizeof(buf), "%d", OLD_PERM_GROUP);
 451                 else if (get_shared_repository() == PERM_EVERYBODY)
 452                         xsnprintf(buf, sizeof(buf), "%d", OLD_PERM_EVERYBODY);
 453                 else
 454                         BUG("invalid value for shared_repository");
 455                 git_config_set("core.sharedrepository", buf);
 456                 git_config_set("receive.denyNonFastforwards", "true");
 457         }
 458
 459         if (!(flags & INIT_DB_QUIET)) {
 460                 int len = strlen(git_dir);
 461
 462                 if (reinit)
 463                         printf(get_shared_repository()
 464                                ? _("Reinitialized existing shared Git repository in %s%s\n")
 465                                : _("Reinitialized existing Git repository in %s%s\n"),
 466                                git_dir, len && git_dir[len-1] != '/' ? "/" : "");
 467                 else
 468                         printf(get_shared_repository()
 469                                ? _("Initialized empty shared Git repository in %s%s\n")
 470                                : _("Initialized empty Git repository in %s%s\n"),
 471                                git_dir, len && git_dir[len-1] != '/' ? "/" : "");
 472         }
 473
 474         free(original_git_dir);
 475         return 0;
 476 }
 477
 478 static int guess_repository_type(const char *git_dir)
 479 {
 480         const char *slash;
 481         char *cwd;
 482         int cwd_is_git_dir;
 483
 484         /*
 485          * "GIT_DIR=. git init" is always bare.
 486          * "GIT_DIR=`pwd` git init" too.
 487          */
 488         if (!strcmp(".", git_dir))
 489                 return 1;
 490         cwd = xgetcwd();
 491         cwd_is_git_dir = !strcmp(git_dir, cwd);
 492         free(cwd);
 493         if (cwd_is_git_dir)
 494                 return 1;
 495         /*
 496          * "GIT_DIR=.git or GIT_DIR=something/.git is usually not.
 497          */
 498         if (!strcmp(git_dir, ".git"))
 499                 return 0;
 500         slash = strrchr(git_dir, '/');
 501         if (slash && !strcmp(slash, "/.git"))
 502                 return 0;
 503
 504         /*
 505          * Otherwise it is often bare.  At this point
 506          * we are just guessing.
 507          */
 508         return 1;
 509 }
 510
 511 static int shared_callback(const struct option *opt, const char *arg, int unset)
 512 {
 513         BUG_ON_OPT_NEG(unset);
 514         *((int *) opt->value) = (arg) ? git_config_perm("arg", arg) : PERM_GROUP;
 515         return 0;
 516 }
 517
 518 static const char *const init_db_usage[] = {
 519         N_("git init [-q | --quiet] [--bare] [--template=<template-directory>]\n"
 520            "         [--separate-git-dir <git-dir>] [--object-format=<format>]\n"
 521            "         [-b <branch-name> | --initial-branch=<branch-name>]\n"
 522            "         [--shared[=<permissions>]] [<directory>]"),
 523         NULL
 524 };
 525
 526 /*
 527  * If you want to, you can share the DB area with any number of branches.
 528  * That has advantages: you can save space by sharing all the SHA1 objects.
 529  * On the other hand, it might just make lookup slower and messier. You
 530  * be the judge.  The default case is to have one DB per managed directory.
 531  */
 532 int cmd_init_db(int argc, const char **argv, const char *prefix)
 533 {
 534         const char *git_dir;
 535         const char *real_git_dir = NULL;
 536         const char *work_tree;
 537         const char *template_dir = NULL;
 538         unsigned int flags = 0;
 539         const char *object_format = NULL;
 540         const char *initial_branch = NULL;
 541         int hash_algo = GIT_HASH_UNKNOWN;
 542         const struct option init_db_options[] = {
 543                 OPT_STRING(0, "template", &template_dir, N_("template-directory"),
 544                                 N_("directory from which templates will be used")),
 545                 OPT_SET_INT(0, "bare", &is_bare_repository_cfg,
 546                                 N_("create a bare repository"), 1),
 547                 { OPTION_CALLBACK, 0, "shared", &init_shared_repository,
 548                         N_("permissions"),
 549                         N_("specify that the git repository is to be shared amongst several users"),
 550                         PARSE_OPT_OPTARG | PARSE_OPT_NONEG, shared_callback, 0},
 551                 OPT_BIT('q', "quiet", &flags, N_("be quiet"), INIT_DB_QUIET),
 552                 OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
 553                            N_("separate git dir from working tree")),
 554                 OPT_STRING('b', "initial-branch", &initial_branch, N_("name"),
 555                            N_("override the name of the initial branch")),
 556                 OPT_STRING(0, "object-format", &object_format, N_("hash"),
 557                            N_("specify the hash algorithm to use")),
 558                 OPT_END()
 559         };
 560
 561         argc = parse_options(argc, argv, prefix, init_db_options, init_db_usage, 0);
 562
 563         if (real_git_dir && is_bare_repository_cfg == 1)
 564                 die(_("options '%s' and '%s' cannot be used together"), "--separate-git-dir", "--bare");
 565
 566         if (real_git_dir && !is_absolute_path(real_git_dir))
 567                 real_git_dir = real_pathdup(real_git_dir, 1);
 568
 569         if (template_dir && *template_dir && !is_absolute_path(template_dir)) {
 570                 template_dir = absolute_pathdup(template_dir);
 571                 UNLEAK(template_dir);
 572         }
 573
 574         if (argc == 1) {
 575                 int mkdir_tried = 0;
 576         retry:
 577                 if (chdir(argv[0]) < 0) {
 578                         if (!mkdir_tried) {
 579                                 int saved;
 580                                 /*
 581                                  * At this point we haven't read any configuration,
 582                                  * and we know shared_repository should always be 0;
 583                                  * but just in case we play safe.
 584                                  */
 585                                 saved = get_shared_repository();
 586                                 set_shared_repository(0);
 587                                 switch (safe_create_leading_directories_const(argv[0])) {
 588                                 case SCLD_OK:
 589                                 case SCLD_PERMS:
 590                                         break;
 591                                 case SCLD_EXISTS:
 592                                         errno = EEXIST;
 593                                         /* fallthru */
 594                                 default:
 595                                         die_errno(_("cannot mkdir %s"), argv[0]);
 596                                         break;
 597                                 }
 598                                 set_shared_repository(saved);
 599                                 if (mkdir(argv[0], 0777) < 0)
 600                                         die_errno(_("cannot mkdir %s"), argv[0]);
 601                                 mkdir_tried = 1;
 602                                 goto retry;
 603                         }
 604                         die_errno(_("cannot chdir to %s"), argv[0]);
 605                 }
 606         } else if (0 < argc) {
 607                 usage(init_db_usage[0]);
 608         }
 609         if (is_bare_repository_cfg == 1) {
 610                 char *cwd = xgetcwd();
 611                 setenv(GIT_DIR_ENVIRONMENT, cwd, argc > 0);
 612                 free(cwd);
 613         }
 614
 615         if (object_format) {
 616                 hash_algo = hash_algo_by_name(object_format);
 617                 if (hash_algo == GIT_HASH_UNKNOWN)
 618                         die(_("unknown hash algorithm '%s'"), object_format);
 619         }
 620
 621         if (init_shared_repository != -1)
 622                 set_shared_repository(init_shared_repository);
 623
 624         /*
 625          * GIT_WORK_TREE makes sense only in conjunction with GIT_DIR
 626          * without --bare.  Catch the error early.
 627          */
 628         git_dir = xstrdup_or_null(getenv(GIT_DIR_ENVIRONMENT));
 629         work_tree = xstrdup_or_null(getenv(GIT_WORK_TREE_ENVIRONMENT));
 630         if ((!git_dir || is_bare_repository_cfg == 1) && work_tree)
 631                 die(_("%s (or --work-tree=<directory>) not allowed without "
 632                           "specifying %s (or --git-dir=<directory>)"),
 633                     GIT_WORK_TREE_ENVIRONMENT,
 634                     GIT_DIR_ENVIRONMENT);
 635
 636         /*
 637          * Set up the default .git directory contents
 638          */
 639         if (!git_dir)
 640                 git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
 641
 642         /*
 643          * When --separate-git-dir is used inside a linked worktree, take
 644          * care to ensure that the common .git/ directory is relocated, not
 645          * the worktree-specific .git/worktrees/<id>/ directory.
 646          */
 647         if (real_git_dir) {
 648                 int err;
 649                 const char *p;
 650                 struct strbuf sb = STRBUF_INIT;
 651
 652                 p = read_gitfile_gently(git_dir, &err);
 653                 if (p && get_common_dir(&sb, p)) {
 654                         struct strbuf mainwt = STRBUF_INIT;
 655
 656                         strbuf_addbuf(&mainwt, &sb);
 657                         strbuf_strip_suffix(&mainwt, "/.git");
 658                         if (chdir(mainwt.buf) < 0)
 659                                 die_errno(_("cannot chdir to %s"), mainwt.buf);
 660                         strbuf_release(&mainwt);
 661                         git_dir = strbuf_detach(&sb, NULL);
 662                 }
 663                 strbuf_release(&sb);
 664         }
 665
 666         if (is_bare_repository_cfg < 0)
 667                 is_bare_repository_cfg = guess_repository_type(git_dir);
 668
 669         if (!is_bare_repository_cfg) {
 670                 const char *git_dir_parent = strrchr(git_dir, '/');
 671                 if (git_dir_parent) {
 672                         char *rel = xstrndup(git_dir, git_dir_parent - git_dir);
 673                         git_work_tree_cfg = real_pathdup(rel, 1);
 674                         free(rel);
 675                 }
 676                 if (!git_work_tree_cfg)
 677                         git_work_tree_cfg = xgetcwd();
 678                 if (work_tree)
 679                         set_git_work_tree(work_tree);
 680                 else
 681                         set_git_work_tree(git_work_tree_cfg);
 682                 if (access(get_git_work_tree(), X_OK))
 683                         die_errno (_("Cannot access work tree '%s'"),
 684                                    get_git_work_tree());
 685         }
 686         else {
 687                 if (real_git_dir)
 688                         die(_("--separate-git-dir incompatible with bare repository"));
 689                 if (work_tree)
 690                         set_git_work_tree(work_tree);
 691         }
 692
 693         UNLEAK(real_git_dir);
 694         UNLEAK(git_dir);
 695         UNLEAK(work_tree);
 696
 697         flags |= INIT_DB_EXIST_OK;
 698         return init_db(git_dir, real_git_dir, template_dir, hash_algo,
 699                        initial_branch, flags);
 700 }