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 "abspath.h"
   8 #include "config.h"
   9 #include "environment.h"
  10 #include "gettext.h"
  11 #include "refs.h"
  12 #include "builtin.h"
  13 #include "exec-cmd.h"
  14 #include "parse-options.h"
  15 #include "setup.h"
  16 #include "worktree.h"
  17 #include "wrapper.h"
  18
  19 #ifndef DEFAULT_GIT_TEMPLATE_DIR
  20 #define DEFAULT_GIT_TEMPLATE_DIR "/usr/share/git-core/templates"
  21 #endif
  22
  23 #ifdef NO_TRUSTABLE_FILEMODE
  24 #define TEST_FILEMODE 0
  25 #else
  26 #define TEST_FILEMODE 1
  27 #endif
  28
  29 #define GIT_DEFAULT_HASH_ENVIRONMENT "GIT_DEFAULT_HASH"
  30
  31 static int init_is_bare_repository = 0;
  32 static int init_shared_repository = -1;
  33
  34 static void copy_templates_1(struct strbuf *path, struct strbuf *template_path,
  35                              DIR *dir)
  36 {
  37         size_t path_baselen = path->len;
  38         size_t template_baselen = template_path->len;
  39         struct dirent *de;
  40
  41         /* Note: if ".git/hooks" file exists in the repository being
  42          * re-initialized, /etc/core-git/templates/hooks/update would
  43          * cause "git init" to fail here.  I think this is sane but
  44          * it means that the set of templates we ship by default, along
  45          * with the way the namespace under .git/ is organized, should
  46          * be really carefully chosen.
  47          */
  48         safe_create_dir(path->buf, 1);
  49         while ((de = readdir(dir)) != NULL) {
  50                 struct stat st_git, st_template;
  51                 int exists = 0;
  52
  53                 strbuf_setlen(path, path_baselen);
  54                 strbuf_setlen(template_path, template_baselen);
  55
  56                 if (de->d_name[0] == '.')
  57                         continue;
  58                 strbuf_addstr(path, de->d_name);
  59                 strbuf_addstr(template_path, de->d_name);
  60                 if (lstat(path->buf, &st_git)) {
  61                         if (errno != ENOENT)
  62                                 die_errno(_("cannot stat '%s'"), path->buf);
  63                 }
  64                 else
  65                         exists = 1;
  66
  67                 if (lstat(template_path->buf, &st_template))
  68                         die_errno(_("cannot stat template '%s'"), template_path->buf);
  69
  70                 if (S_ISDIR(st_template.st_mode)) {
  71                         DIR *subdir = opendir(template_path->buf);
  72                         if (!subdir)
  73                                 die_errno(_("cannot opendir '%s'"), template_path->buf);
  74                         strbuf_addch(path, '/');
  75                         strbuf_addch(template_path, '/');
  76                         copy_templates_1(path, template_path, subdir);
  77                         closedir(subdir);
  78                 }
  79                 else if (exists)
  80                         continue;
  81                 else if (S_ISLNK(st_template.st_mode)) {
  82                         struct strbuf lnk = STRBUF_INIT;
  83                         if (strbuf_readlink(&lnk, template_path->buf,
  84                                             st_template.st_size) < 0)
  85                                 die_errno(_("cannot readlink '%s'"), template_path->buf);
  86                         if (symlink(lnk.buf, path->buf))
  87                                 die_errno(_("cannot symlink '%s' '%s'"),
  88                                           lnk.buf, path->buf);
  89                         strbuf_release(&lnk);
  90                 }
  91                 else if (S_ISREG(st_template.st_mode)) {
  92                         if (copy_file(path->buf, template_path->buf, st_template.st_mode))
  93                                 die_errno(_("cannot copy '%s' to '%s'"),
  94                                           template_path->buf, path->buf);
  95                 }
  96                 else
  97                         error(_("ignoring template %s"), template_path->buf);
  98         }
  99 }
 100
 101 static void copy_templates(const char *template_dir, const char *init_template_dir)
 102 {
 103         struct strbuf path = STRBUF_INIT;
 104         struct strbuf template_path = STRBUF_INIT;
 105         size_t template_len;
 106         struct repository_format template_format = REPOSITORY_FORMAT_INIT;
 107         struct strbuf err = STRBUF_INIT;
 108         DIR *dir;
 109         char *to_free = NULL;
 110
 111         if (!template_dir)
 112                 template_dir = getenv(TEMPLATE_DIR_ENVIRONMENT);
 113         if (!template_dir)
 114                 template_dir = init_template_dir;
 115         if (!template_dir)
 116                 template_dir = to_free = system_path(DEFAULT_GIT_TEMPLATE_DIR);
 117         if (!template_dir[0]) {
 118                 free(to_free);
 119                 return;
 120         }
 121
 122         strbuf_addstr(&template_path, template_dir);
 123         strbuf_complete(&template_path, '/');
 124         template_len = template_path.len;
 125
 126         dir = opendir(template_path.buf);
 127         if (!dir) {
 128                 warning(_("templates not found in %s"), template_dir);
 129                 goto free_return;
 130         }
 131
 132         /* Make sure that template is from the correct vintage */
 133         strbuf_addstr(&template_path, "config");
 134         read_repository_format(&template_format, template_path.buf);
 135         strbuf_setlen(&template_path, template_len);
 136
 137         /*
 138          * No mention of version at all is OK, but anything else should be
 139          * verified.
 140          */
 141         if (template_format.version >= 0 &&
 142             verify_repository_format(&template_format, &err) < 0) {
 143                 warning(_("not copying templates from '%s': %s"),
 144                           template_dir, err.buf);
 145                 strbuf_release(&err);
 146                 goto close_free_return;
 147         }
 148
 149         strbuf_addstr(&path, get_git_common_dir());
 150         strbuf_complete(&path, '/');
 151         copy_templates_1(&path, &template_path, dir);
 152 close_free_return:
 153         closedir(dir);
 154 free_return:
 155         free(to_free);
 156         strbuf_release(&path);
 157         strbuf_release(&template_path);
 158         clear_repository_format(&template_format);
 159 }
 160
 161 /*
 162  * If the git_dir is not directly inside the working tree, then git will not
 163  * find it by default, and we need to set the worktree explicitly.
 164  */
 165 static int needs_work_tree_config(const char *git_dir, const char *work_tree)
 166 {
 167         if (!strcmp(work_tree, "/") && !strcmp(git_dir, "/.git"))
 168                 return 0;
 169         if (skip_prefix(git_dir, work_tree, &git_dir) &&
 170             !strcmp(git_dir, "/.git"))
 171                 return 0;
 172         return 1;
 173 }
 174
 175 void initialize_repository_version(int hash_algo, int reinit)
 176 {
 177         char repo_version_string[10];
 178         int repo_version = GIT_REPO_VERSION;
 179
 180         if (hash_algo != GIT_HASH_SHA1)
 181                 repo_version = GIT_REPO_VERSION_READ;
 182
 183         /* This forces creation of new config file */
 184         xsnprintf(repo_version_string, sizeof(repo_version_string),
 185                   "%d", repo_version);
 186         git_config_set("core.repositoryformatversion", repo_version_string);
 187
 188         if (hash_algo != GIT_HASH_SHA1)
 189                 git_config_set("extensions.objectformat",
 190                                hash_algos[hash_algo].name);
 191         else if (reinit)
 192                 git_config_set_gently("extensions.objectformat", NULL);
 193 }
 194
 195 static int create_default_files(const char *template_path,
 196                                 const char *original_git_dir,
 197                                 const char *initial_branch,
 198                                 const struct repository_format *fmt,
 199                                 int quiet)
 200 {
 201         struct stat st1;
 202         struct strbuf buf = STRBUF_INIT;
 203         char *path;
 204         char junk[2];
 205         int reinit;
 206         int filemode;
 207         struct strbuf err = STRBUF_INIT;
 208         const char *init_template_dir = NULL;
 209         const char *work_tree = get_git_work_tree();
 210
 211         /*
 212          * First copy the templates -- we might have the default
 213          * config file there, in which case we would want to read
 214          * from it after installing.
 215          *
 216          * Before reading that config, we also need to clear out any cached
 217          * values (since we've just potentially changed what's available on
 218          * disk).
 219          */
 220         git_config_get_pathname("init.templatedir", &init_template_dir);
 221         copy_templates(template_path, init_template_dir);
 222         free((char *)init_template_dir);
 223         git_config_clear();
 224         reset_shared_repository();
 225         git_config(git_default_config, NULL);
 226
 227         /*
 228          * We must make sure command-line options continue to override any
 229          * values we might have just re-read from the config.
 230          */
 231         is_bare_repository_cfg = init_is_bare_repository || !work_tree;
 232         if (init_shared_repository != -1)
 233                 set_shared_repository(init_shared_repository);
 234
 235         /*
 236          * We would have created the above under user's umask -- under
 237          * shared-repository settings, we would need to fix them up.
 238          */
 239         if (get_shared_repository()) {
 240                 adjust_shared_perm(get_git_dir());
 241         }
 242
 243         /*
 244          * We need to create a "refs" dir in any case so that older
 245          * versions of git can tell that this is a repository.
 246          */
 247         safe_create_dir(git_path("refs"), 1);
 248         adjust_shared_perm(git_path("refs"));
 249
 250         if (refs_init_db(&err))
 251                 die("failed to set up refs db: %s", err.buf);
 252
 253         /*
 254          * Point the HEAD symref to the initial branch with if HEAD does
 255          * not yet exist.
 256          */
 257         path = git_path_buf(&buf, "HEAD");
 258         reinit = (!access(path, R_OK)
 259                   || readlink(path, junk, sizeof(junk)-1) != -1);
 260         if (!reinit) {
 261                 char *ref;
 262
 263                 if (!initial_branch)
 264                         initial_branch = git_default_branch_name(quiet);
 265
 266                 ref = xstrfmt("refs/heads/%s", initial_branch);
 267                 if (check_refname_format(ref, 0) < 0)
 268                         die(_("invalid initial branch name: '%s'"),
 269                             initial_branch);
 270
 271                 if (create_symref("HEAD", ref, NULL) < 0)
 272                         exit(1);
 273                 free(ref);
 274         }
 275
 276         initialize_repository_version(fmt->hash_algo, 0);
 277
 278         /* Check filemode trustability */
 279         path = git_path_buf(&buf, "config");
 280         filemode = TEST_FILEMODE;
 281         if (TEST_FILEMODE && !lstat(path, &st1)) {
 282                 struct stat st2;
 283                 filemode = (!chmod(path, st1.st_mode ^ S_IXUSR) &&
 284                                 !lstat(path, &st2) &&
 285                                 st1.st_mode != st2.st_mode &&
 286                                 !chmod(path, st1.st_mode));
 287                 if (filemode && !reinit && (st1.st_mode & S_IXUSR))
 288                         filemode = 0;
 289         }
 290         git_config_set("core.filemode", filemode ? "true" : "false");
 291
 292         if (is_bare_repository())
 293                 git_config_set("core.bare", "true");
 294         else {
 295                 git_config_set("core.bare", "false");
 296                 /* allow template config file to override the default */
 297                 if (log_all_ref_updates == LOG_REFS_UNSET)
 298                         git_config_set("core.logallrefupdates", "true");
 299                 if (needs_work_tree_config(original_git_dir, work_tree))
 300                         git_config_set("core.worktree", work_tree);
 301         }
 302
 303         if (!reinit) {
 304                 /* Check if symlink is supported in the work tree */
 305                 path = git_path_buf(&buf, "tXXXXXX");
 306                 if (!close(xmkstemp(path)) &&
 307                     !unlink(path) &&
 308                     !symlink("testing", path) &&
 309                     !lstat(path, &st1) &&
 310                     S_ISLNK(st1.st_mode))
 311                         unlink(path); /* good */
 312                 else
 313                         git_config_set("core.symlinks", "false");
 314
 315                 /* Check if the filesystem is case-insensitive */
 316                 path = git_path_buf(&buf, "CoNfIg");
 317                 if (!access(path, F_OK))
 318                         git_config_set("core.ignorecase", "true");
 319                 probe_utf8_pathname_composition();
 320         }
 321
 322         strbuf_release(&buf);
 323         return reinit;
 324 }
 325
 326 static void create_object_directory(void)
 327 {
 328         struct strbuf path = STRBUF_INIT;
 329         size_t baselen;
 330
 331         strbuf_addstr(&path, get_object_directory());
 332         baselen = path.len;
 333
 334         safe_create_dir(path.buf, 1);
 335
 336         strbuf_setlen(&path, baselen);
 337         strbuf_addstr(&path, "/pack");
 338         safe_create_dir(path.buf, 1);
 339
 340         strbuf_setlen(&path, baselen);
 341         strbuf_addstr(&path, "/info");
 342         safe_create_dir(path.buf, 1);
 343
 344         strbuf_release(&path);
 345 }
 346
 347 static void separate_git_dir(const char *git_dir, const char *git_link)
 348 {
 349         struct stat st;
 350
 351         if (!stat(git_link, &st)) {
 352                 const char *src;
 353
 354                 if (S_ISREG(st.st_mode))
 355                         src = read_gitfile(git_link);
 356                 else if (S_ISDIR(st.st_mode))
 357                         src = git_link;
 358                 else
 359                         die(_("unable to handle file type %d"), (int)st.st_mode);
 360
 361                 if (rename(src, git_dir))
 362                         die_errno(_("unable to move %s to %s"), src, git_dir);
 363                 repair_worktrees(NULL, NULL);
 364         }
 365
 366         write_file(git_link, "gitdir: %s", git_dir);
 367 }
 368
 369 static void validate_hash_algorithm(struct repository_format *repo_fmt, int hash)
 370 {
 371         const char *env = getenv(GIT_DEFAULT_HASH_ENVIRONMENT);
 372         /*
 373          * If we already have an initialized repo, don't allow the user to
 374          * specify a different algorithm, as that could cause corruption.
 375          * Otherwise, if the user has specified one on the command line, use it.
 376          */
 377         if (repo_fmt->version >= 0 && hash != GIT_HASH_UNKNOWN && hash != repo_fmt->hash_algo)
 378                 die(_("attempt to reinitialize repository with different hash"));
 379         else if (hash != GIT_HASH_UNKNOWN)
 380                 repo_fmt->hash_algo = hash;
 381         else if (env) {
 382                 int env_algo = hash_algo_by_name(env);
 383                 if (env_algo == GIT_HASH_UNKNOWN)
 384                         die(_("unknown hash algorithm '%s'"), env);
 385                 repo_fmt->hash_algo = env_algo;
 386         }
 387 }
 388
 389 int init_db(const char *git_dir, const char *real_git_dir,
 390             const char *template_dir, int hash, const char *initial_branch,
 391             unsigned int flags)
 392 {
 393         int reinit;
 394         int exist_ok = flags & INIT_DB_EXIST_OK;
 395         char *original_git_dir = real_pathdup(git_dir, 1);
 396         struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT;
 397
 398         if (real_git_dir) {
 399                 struct stat st;
 400
 401                 if (!exist_ok && !stat(git_dir, &st))
 402                         die(_("%s already exists"), git_dir);
 403
 404                 if (!exist_ok && !stat(real_git_dir, &st))
 405                         die(_("%s already exists"), real_git_dir);
 406
 407                 set_git_dir(real_git_dir, 1);
 408                 git_dir = get_git_dir();
 409                 separate_git_dir(git_dir, original_git_dir);
 410         }
 411         else {
 412                 set_git_dir(git_dir, 1);
 413                 git_dir = get_git_dir();
 414         }
 415         startup_info->have_repository = 1;
 416
 417         /* Ensure `core.hidedotfiles` is processed */
 418         git_config(platform_core_config, NULL);
 419
 420         safe_create_dir(git_dir, 0);
 421
 422         init_is_bare_repository = is_bare_repository();
 423
 424         /* Check to see if the repository version is right.
 425          * Note that a newly created repository does not have
 426          * config file, so this will not fail.  What we are catching
 427          * is an attempt to reinitialize new repository with an old tool.
 428          */
 429         check_repository_format(&repo_fmt);
 430
 431         validate_hash_algorithm(&repo_fmt, hash);
 432
 433         reinit = create_default_files(template_dir, original_git_dir,
 434                                       initial_branch, &repo_fmt,
 435                                       flags & INIT_DB_QUIET);
 436         if (reinit && initial_branch)
 437                 warning(_("re-init: ignored --initial-branch=%s"),
 438                         initial_branch);
 439
 440         create_object_directory();
 441
 442         if (get_shared_repository()) {
 443                 char buf[10];
 444                 /* We do not spell "group" and such, so that
 445                  * the configuration can be read by older version
 446                  * of git. Note, we use octal numbers for new share modes,
 447                  * and compatibility values for PERM_GROUP and
 448                  * PERM_EVERYBODY.
 449                  */
 450                 if (get_shared_repository() < 0)
 451                         /* force to the mode value */
 452                         xsnprintf(buf, sizeof(buf), "0%o", -get_shared_repository());
 453                 else if (get_shared_repository() == PERM_GROUP)
 454                         xsnprintf(buf, sizeof(buf), "%d", OLD_PERM_GROUP);
 455                 else if (get_shared_repository() == PERM_EVERYBODY)
 456                         xsnprintf(buf, sizeof(buf), "%d", OLD_PERM_EVERYBODY);
 457                 else
 458                         BUG("invalid value for shared_repository");
 459                 git_config_set("core.sharedrepository", buf);
 460                 git_config_set("receive.denyNonFastforwards", "true");
 461         }
 462
 463         if (!(flags & INIT_DB_QUIET)) {
 464                 int len = strlen(git_dir);
 465
 466                 if (reinit)
 467                         printf(get_shared_repository()
 468                                ? _("Reinitialized existing shared Git repository in %s%s\n")
 469                                : _("Reinitialized existing Git repository in %s%s\n"),
 470                                git_dir, len && git_dir[len-1] != '/' ? "/" : "");
 471                 else
 472                         printf(get_shared_repository()
 473                                ? _("Initialized empty shared Git repository in %s%s\n")
 474                                : _("Initialized empty Git repository in %s%s\n"),
 475                                git_dir, len && git_dir[len-1] != '/' ? "/" : "");
 476         }
 477
 478         free(original_git_dir);
 479         return 0;
 480 }
 481
 482 static int guess_repository_type(const char *git_dir)
 483 {
 484         const char *slash;
 485         char *cwd;
 486         int cwd_is_git_dir;
 487
 488         /*
 489          * "GIT_DIR=. git init" is always bare.
 490          * "GIT_DIR=`pwd` git init" too.
 491          */
 492         if (!strcmp(".", git_dir))
 493                 return 1;
 494         cwd = xgetcwd();
 495         cwd_is_git_dir = !strcmp(git_dir, cwd);
 496         free(cwd);
 497         if (cwd_is_git_dir)
 498                 return 1;
 499         /*
 500          * "GIT_DIR=.git or GIT_DIR=something/.git is usually not.
 501          */
 502         if (!strcmp(git_dir, ".git"))
 503                 return 0;
 504         slash = strrchr(git_dir, '/');
 505         if (slash && !strcmp(slash, "/.git"))
 506                 return 0;
 507
 508         /*
 509          * Otherwise it is often bare.  At this point
 510          * we are just guessing.
 511          */
 512         return 1;
 513 }
 514
 515 static int shared_callback(const struct option *opt, const char *arg, int unset)
 516 {
 517         BUG_ON_OPT_NEG(unset);
 518         *((int *) opt->value) = (arg) ? git_config_perm("arg", arg) : PERM_GROUP;
 519         return 0;
 520 }
 521
 522 static const char *const init_db_usage[] = {
 523         N_("git init [-q | --quiet] [--bare] [--template=<template-directory>]\n"
 524            "         [--separate-git-dir <git-dir>] [--object-format=<format>]\n"
 525            "         [-b <branch-name> | --initial-branch=<branch-name>]\n"
 526            "         [--shared[=<permissions>]] [<directory>]"),
 527         NULL
 528 };
 529
 530 /*
 531  * If you want to, you can share the DB area with any number of branches.
 532  * That has advantages: you can save space by sharing all the SHA1 objects.
 533  * On the other hand, it might just make lookup slower and messier. You
 534  * be the judge.  The default case is to have one DB per managed directory.
 535  */
 536 int cmd_init_db(int argc, const char **argv, const char *prefix)
 537 {
 538         const char *git_dir;
 539         const char *real_git_dir = NULL;
 540         const char *work_tree;
 541         const char *template_dir = NULL;
 542         unsigned int flags = 0;
 543         const char *object_format = NULL;
 544         const char *initial_branch = NULL;
 545         int hash_algo = GIT_HASH_UNKNOWN;
 546         const struct option init_db_options[] = {
 547                 OPT_STRING(0, "template", &template_dir, N_("template-directory"),
 548                                 N_("directory from which templates will be used")),
 549                 OPT_SET_INT(0, "bare", &is_bare_repository_cfg,
 550                                 N_("create a bare repository"), 1),
 551                 { OPTION_CALLBACK, 0, "shared", &init_shared_repository,
 552                         N_("permissions"),
 553                         N_("specify that the git repository is to be shared amongst several users"),
 554                         PARSE_OPT_OPTARG | PARSE_OPT_NONEG, shared_callback, 0},
 555                 OPT_BIT('q', "quiet", &flags, N_("be quiet"), INIT_DB_QUIET),
 556                 OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
 557                            N_("separate git dir from working tree")),
 558                 OPT_STRING('b', "initial-branch", &initial_branch, N_("name"),
 559                            N_("override the name of the initial branch")),
 560                 OPT_STRING(0, "object-format", &object_format, N_("hash"),
 561                            N_("specify the hash algorithm to use")),
 562                 OPT_END()
 563         };
 564
 565         argc = parse_options(argc, argv, prefix, init_db_options, init_db_usage, 0);
 566
 567         if (real_git_dir && is_bare_repository_cfg == 1)
 568                 die(_("options '%s' and '%s' cannot be used together"), "--separate-git-dir", "--bare");
 569
 570         if (real_git_dir && !is_absolute_path(real_git_dir))
 571                 real_git_dir = real_pathdup(real_git_dir, 1);
 572
 573         if (template_dir && *template_dir && !is_absolute_path(template_dir)) {
 574                 template_dir = absolute_pathdup(template_dir);
 575                 UNLEAK(template_dir);
 576         }
 577
 578         if (argc == 1) {
 579                 int mkdir_tried = 0;
 580         retry:
 581                 if (chdir(argv[0]) < 0) {
 582                         if (!mkdir_tried) {
 583                                 int saved;
 584                                 /*
 585                                  * At this point we haven't read any configuration,
 586                                  * and we know shared_repository should always be 0;
 587                                  * but just in case we play safe.
 588                                  */
 589                                 saved = get_shared_repository();
 590                                 set_shared_repository(0);
 591                                 switch (safe_create_leading_directories_const(argv[0])) {
 592                                 case SCLD_OK:
 593                                 case SCLD_PERMS:
 594                                         break;
 595                                 case SCLD_EXISTS:
 596                                         errno = EEXIST;
 597                                         /* fallthru */
 598                                 default:
 599                                         die_errno(_("cannot mkdir %s"), argv[0]);
 600                                         break;
 601                                 }
 602                                 set_shared_repository(saved);
 603                                 if (mkdir(argv[0], 0777) < 0)
 604                                         die_errno(_("cannot mkdir %s"), argv[0]);
 605                                 mkdir_tried = 1;
 606                                 goto retry;
 607                         }
 608                         die_errno(_("cannot chdir to %s"), argv[0]);
 609                 }
 610         } else if (0 < argc) {
 611                 usage(init_db_usage[0]);
 612         }
 613         if (is_bare_repository_cfg == 1) {
 614                 char *cwd = xgetcwd();
 615                 setenv(GIT_DIR_ENVIRONMENT, cwd, argc > 0);
 616                 free(cwd);
 617         }
 618
 619         if (object_format) {
 620                 hash_algo = hash_algo_by_name(object_format);
 621                 if (hash_algo == GIT_HASH_UNKNOWN)
 622                         die(_("unknown hash algorithm '%s'"), object_format);
 623         }
 624
 625         if (init_shared_repository != -1)
 626                 set_shared_repository(init_shared_repository);
 627
 628         /*
 629          * GIT_WORK_TREE makes sense only in conjunction with GIT_DIR
 630          * without --bare.  Catch the error early.
 631          */
 632         git_dir = xstrdup_or_null(getenv(GIT_DIR_ENVIRONMENT));
 633         work_tree = xstrdup_or_null(getenv(GIT_WORK_TREE_ENVIRONMENT));
 634         if ((!git_dir || is_bare_repository_cfg == 1) && work_tree)
 635                 die(_("%s (or --work-tree=<directory>) not allowed without "
 636                           "specifying %s (or --git-dir=<directory>)"),
 637                     GIT_WORK_TREE_ENVIRONMENT,
 638                     GIT_DIR_ENVIRONMENT);
 639
 640         /*
 641          * Set up the default .git directory contents
 642          */
 643         if (!git_dir)
 644                 git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
 645
 646         /*
 647          * When --separate-git-dir is used inside a linked worktree, take
 648          * care to ensure that the common .git/ directory is relocated, not
 649          * the worktree-specific .git/worktrees/<id>/ directory.
 650          */
 651         if (real_git_dir) {
 652                 int err;
 653                 const char *p;
 654                 struct strbuf sb = STRBUF_INIT;
 655
 656                 p = read_gitfile_gently(git_dir, &err);
 657                 if (p && get_common_dir(&sb, p)) {
 658                         struct strbuf mainwt = STRBUF_INIT;
 659
 660                         strbuf_addbuf(&mainwt, &sb);
 661                         strbuf_strip_suffix(&mainwt, "/.git");
 662                         if (chdir(mainwt.buf) < 0)
 663                                 die_errno(_("cannot chdir to %s"), mainwt.buf);
 664                         strbuf_release(&mainwt);
 665                         git_dir = strbuf_detach(&sb, NULL);
 666                 }
 667                 strbuf_release(&sb);
 668         }
 669
 670         if (is_bare_repository_cfg < 0)
 671                 is_bare_repository_cfg = guess_repository_type(git_dir);
 672
 673         if (!is_bare_repository_cfg) {
 674                 const char *git_dir_parent = strrchr(git_dir, '/');
 675                 if (git_dir_parent) {
 676                         char *rel = xstrndup(git_dir, git_dir_parent - git_dir);
 677                         git_work_tree_cfg = real_pathdup(rel, 1);
 678                         free(rel);
 679                 }
 680                 if (!git_work_tree_cfg)
 681                         git_work_tree_cfg = xgetcwd();
 682                 if (work_tree)
 683                         set_git_work_tree(work_tree);
 684                 else
 685                         set_git_work_tree(git_work_tree_cfg);
 686                 if (access(get_git_work_tree(), X_OK))
 687                         die_errno (_("Cannot access work tree '%s'"),
 688                                    get_git_work_tree());
 689         }
 690         else {
 691                 if (real_git_dir)
 692                         die(_("--separate-git-dir incompatible with bare repository"));
 693                 if (work_tree)
 694                         set_git_work_tree(work_tree);
 695         }
 696
 697         UNLEAK(real_git_dir);
 698         UNLEAK(git_dir);
 699         UNLEAK(work_tree);
 700
 701         flags |= INIT_DB_EXIST_OK;
 702         return init_db(git_dir, real_git_dir, template_dir, hash_algo,
 703                        initial_branch, flags);
 704 }