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 "copy.h"
  10 #include "environment.h"
  11 #include "gettext.h"
  12 #include "refs.h"
  13 #include "builtin.h"
  14 #include "exec-cmd.h"
  15 #include "object-file.h"
  16 #include "parse-options.h"
  17 #include "setup.h"
  18 #include "worktree.h"
  19 #include "wrapper.h"
  20
  21 #ifndef DEFAULT_GIT_TEMPLATE_DIR
  22 #define DEFAULT_GIT_TEMPLATE_DIR "/usr/share/git-core/templates"
  23 #endif
  24
  25 #ifdef NO_TRUSTABLE_FILEMODE
  26 #define TEST_FILEMODE 0
  27 #else
  28 #define TEST_FILEMODE 1
  29 #endif
  30
  31 #define GIT_DEFAULT_HASH_ENVIRONMENT "GIT_DEFAULT_HASH"
  32
  33 static int init_is_bare_repository = 0;
  34 static int init_shared_repository = -1;
  35
  36 static void copy_templates_1(struct strbuf *path, struct strbuf *template_path,
  37                              DIR *dir)
  38 {
  39         size_t path_baselen = path->len;
  40         size_t template_baselen = template_path->len;
  41         struct dirent *de;
  42
  43         /* Note: if ".git/hooks" file exists in the repository being
  44          * re-initialized, /etc/core-git/templates/hooks/update would
  45          * cause "git init" to fail here.  I think this is sane but
  46          * it means that the set of templates we ship by default, along
  47          * with the way the namespace under .git/ is organized, should
  48          * be really carefully chosen.
  49          */
  50         safe_create_dir(path->buf, 1);
  51         while ((de = readdir(dir)) != NULL) {
  52                 struct stat st_git, st_template;
  53                 int exists = 0;
  54
  55                 strbuf_setlen(path, path_baselen);
  56                 strbuf_setlen(template_path, template_baselen);
  57
  58                 if (de->d_name[0] == '.')
  59                         continue;
  60                 strbuf_addstr(path, de->d_name);
  61                 strbuf_addstr(template_path, de->d_name);
  62                 if (lstat(path->buf, &st_git)) {
  63                         if (errno != ENOENT)
  64                                 die_errno(_("cannot stat '%s'"), path->buf);
  65                 }
  66                 else
  67                         exists = 1;
  68
  69                 if (lstat(template_path->buf, &st_template))
  70                         die_errno(_("cannot stat template '%s'"), template_path->buf);
  71
  72                 if (S_ISDIR(st_template.st_mode)) {
  73                         DIR *subdir = opendir(template_path->buf);
  74                         if (!subdir)
  75                                 die_errno(_("cannot opendir '%s'"), template_path->buf);
  76                         strbuf_addch(path, '/');
  77                         strbuf_addch(template_path, '/');
  78                         copy_templates_1(path, template_path, subdir);
  79                         closedir(subdir);
  80                 }
  81                 else if (exists)
  82                         continue;
  83                 else if (S_ISLNK(st_template.st_mode)) {
  84                         struct strbuf lnk = STRBUF_INIT;
  85                         if (strbuf_readlink(&lnk, template_path->buf,
  86                                             st_template.st_size) < 0)
  87                                 die_errno(_("cannot readlink '%s'"), template_path->buf);
  88                         if (symlink(lnk.buf, path->buf))
  89                                 die_errno(_("cannot symlink '%s' '%s'"),
  90                                           lnk.buf, path->buf);
  91                         strbuf_release(&lnk);
  92                 }
  93                 else if (S_ISREG(st_template.st_mode)) {
  94                         if (copy_file(path->buf, template_path->buf, st_template.st_mode))
  95                                 die_errno(_("cannot copy '%s' to '%s'"),
  96                                           template_path->buf, path->buf);
  97                 }
  98                 else
  99                         error(_("ignoring template %s"), template_path->buf);
 100         }
 101 }
 102
 103 static void copy_templates(const char *template_dir, const char *init_template_dir)
 104 {
 105         struct strbuf path = STRBUF_INIT;
 106         struct strbuf template_path = STRBUF_INIT;
 107         size_t template_len;
 108         struct repository_format template_format = REPOSITORY_FORMAT_INIT;
 109         struct strbuf err = STRBUF_INIT;
 110         DIR *dir;
 111         char *to_free = NULL;
 112
 113         if (!template_dir)
 114                 template_dir = getenv(TEMPLATE_DIR_ENVIRONMENT);
 115         if (!template_dir)
 116                 template_dir = init_template_dir;
 117         if (!template_dir)
 118                 template_dir = to_free = system_path(DEFAULT_GIT_TEMPLATE_DIR);
 119         if (!template_dir[0]) {
 120                 free(to_free);
 121                 return;
 122         }
 123
 124         strbuf_addstr(&template_path, template_dir);
 125         strbuf_complete(&template_path, '/');
 126         template_len = template_path.len;
 127
 128         dir = opendir(template_path.buf);
 129         if (!dir) {
 130                 warning(_("templates not found in %s"), template_dir);
 131                 goto free_return;
 132         }
 133
 134         /* Make sure that template is from the correct vintage */
 135         strbuf_addstr(&template_path, "config");
 136         read_repository_format(&template_format, template_path.buf);
 137         strbuf_setlen(&template_path, template_len);
 138
 139         /*
 140          * No mention of version at all is OK, but anything else should be
 141          * verified.
 142          */
 143         if (template_format.version >= 0 &&
 144             verify_repository_format(&template_format, &err) < 0) {
 145                 warning(_("not copying templates from '%s': %s"),
 146                           template_dir, err.buf);
 147                 strbuf_release(&err);
 148                 goto close_free_return;
 149         }
 150
 151         strbuf_addstr(&path, get_git_common_dir());
 152         strbuf_complete(&path, '/');
 153         copy_templates_1(&path, &template_path, dir);
 154 close_free_return:
 155         closedir(dir);
 156 free_return:
 157         free(to_free);
 158         strbuf_release(&path);
 159         strbuf_release(&template_path);
 160         clear_repository_format(&template_format);
 161 }
 162
 163 /*
 164  * If the git_dir is not directly inside the working tree, then git will not
 165  * find it by default, and we need to set the worktree explicitly.
 166  */
 167 static int needs_work_tree_config(const char *git_dir, const char *work_tree)
 168 {
 169         if (!strcmp(work_tree, "/") && !strcmp(git_dir, "/.git"))
 170                 return 0;
 171         if (skip_prefix(git_dir, work_tree, &git_dir) &&
 172             !strcmp(git_dir, "/.git"))
 173                 return 0;
 174         return 1;
 175 }
 176
 177 void initialize_repository_version(int hash_algo, int reinit)
 178 {
 179         char repo_version_string[10];
 180         int repo_version = GIT_REPO_VERSION;
 181
 182         if (hash_algo != GIT_HASH_SHA1)
 183                 repo_version = GIT_REPO_VERSION_READ;
 184
 185         /* This forces creation of new config file */
 186         xsnprintf(repo_version_string, sizeof(repo_version_string),
 187                   "%d", repo_version);
 188         git_config_set("core.repositoryformatversion", repo_version_string);
 189
 190         if (hash_algo != GIT_HASH_SHA1)
 191                 git_config_set("extensions.objectformat",
 192                                hash_algos[hash_algo].name);
 193         else if (reinit)
 194                 git_config_set_gently("extensions.objectformat", NULL);
 195 }
 196
 197 static int create_default_files(const char *template_path,
 198                                 const char *original_git_dir,
 199                                 const char *initial_branch,
 200                                 const struct repository_format *fmt,
 201                                 int quiet)
 202 {
 203         struct stat st1;
 204         struct strbuf buf = STRBUF_INIT;
 205         char *path;
 206         char junk[2];
 207         int reinit;
 208         int filemode;
 209         struct strbuf err = STRBUF_INIT;
 210         const char *init_template_dir = NULL;
 211         const char *work_tree = get_git_work_tree();
 212
 213         /*
 214          * First copy the templates -- we might have the default
 215          * config file there, in which case we would want to read
 216          * from it after installing.
 217          *
 218          * Before reading that config, we also need to clear out any cached
 219          * values (since we've just potentially changed what's available on
 220          * disk).
 221          */
 222         git_config_get_pathname("init.templatedir", &init_template_dir);
 223         copy_templates(template_path, init_template_dir);
 224         free((char *)init_template_dir);
 225         git_config_clear();
 226         reset_shared_repository();
 227         git_config(git_default_config, NULL);
 228
 229         /*
 230          * We must make sure command-line options continue to override any
 231          * values we might have just re-read from the config.
 232          */
 233         is_bare_repository_cfg = init_is_bare_repository || !work_tree;
 234         if (init_shared_repository != -1)
 235                 set_shared_repository(init_shared_repository);
 236
 237         /*
 238          * We would have created the above under user's umask -- under
 239          * shared-repository settings, we would need to fix them up.
 240          */
 241         if (get_shared_repository()) {
 242                 adjust_shared_perm(get_git_dir());
 243         }
 244
 245         /*
 246          * We need to create a "refs" dir in any case so that older
 247          * versions of git can tell that this is a repository.
 248          */
 249         safe_create_dir(git_path("refs"), 1);
 250         adjust_shared_perm(git_path("refs"));
 251
 252         if (refs_init_db(&err))
 253                 die("failed to set up refs db: %s", err.buf);
 254
 255         /*
 256          * Point the HEAD symref to the initial branch with if HEAD does
 257          * not yet exist.
 258          */
 259         path = git_path_buf(&buf, "HEAD");
 260         reinit = (!access(path, R_OK)
 261                   || readlink(path, junk, sizeof(junk)-1) != -1);
 262         if (!reinit) {
 263                 char *ref;
 264
 265                 if (!initial_branch)
 266                         initial_branch = git_default_branch_name(quiet);
 267
 268                 ref = xstrfmt("refs/heads/%s", initial_branch);
 269                 if (check_refname_format(ref, 0) < 0)
 270                         die(_("invalid initial branch name: '%s'"),
 271                             initial_branch);
 272
 273                 if (create_symref("HEAD", ref, NULL) < 0)
 274                         exit(1);
 275                 free(ref);
 276         }
 277
 278         initialize_repository_version(fmt->hash_algo, 0);
 279
 280         /* Check filemode trustability */
 281         path = git_path_buf(&buf, "config");
 282         filemode = TEST_FILEMODE;
 283         if (TEST_FILEMODE && !lstat(path, &st1)) {
 284                 struct stat st2;
 285                 filemode = (!chmod(path, st1.st_mode ^ S_IXUSR) &&
 286                                 !lstat(path, &st2) &&
 287                                 st1.st_mode != st2.st_mode &&
 288                                 !chmod(path, st1.st_mode));
 289                 if (filemode && !reinit && (st1.st_mode & S_IXUSR))
 290                         filemode = 0;
 291         }
 292         git_config_set("core.filemode", filemode ? "true" : "false");
 293
 294         if (is_bare_repository())
 295                 git_config_set("core.bare", "true");
 296         else {
 297                 git_config_set("core.bare", "false");
 298                 /* allow template config file to override the default */
 299                 if (log_all_ref_updates == LOG_REFS_UNSET)
 300                         git_config_set("core.logallrefupdates", "true");
 301                 if (needs_work_tree_config(original_git_dir, work_tree))
 302                         git_config_set("core.worktree", work_tree);
 303         }
 304
 305         if (!reinit) {
 306                 /* Check if symlink is supported in the work tree */
 307                 path = git_path_buf(&buf, "tXXXXXX");
 308                 if (!close(xmkstemp(path)) &&
 309                     !unlink(path) &&
 310                     !symlink("testing", path) &&
 311                     !lstat(path, &st1) &&
 312                     S_ISLNK(st1.st_mode))
 313                         unlink(path); /* good */
 314                 else
 315                         git_config_set("core.symlinks", "false");
 316
 317                 /* Check if the filesystem is case-insensitive */
 318                 path = git_path_buf(&buf, "CoNfIg");
 319                 if (!access(path, F_OK))
 320                         git_config_set("core.ignorecase", "true");
 321                 probe_utf8_pathname_composition();
 322         }
 323
 324         strbuf_release(&buf);
 325         return reinit;
 326 }
 327
 328 static void create_object_directory(void)
 329 {
 330         struct strbuf path = STRBUF_INIT;
 331         size_t baselen;
 332
 333         strbuf_addstr(&path, get_object_directory());
 334         baselen = path.len;
 335
 336         safe_create_dir(path.buf, 1);
 337
 338         strbuf_setlen(&path, baselen);
 339         strbuf_addstr(&path, "/pack");
 340         safe_create_dir(path.buf, 1);
 341
 342         strbuf_setlen(&path, baselen);
 343         strbuf_addstr(&path, "/info");
 344         safe_create_dir(path.buf, 1);
 345
 346         strbuf_release(&path);
 347 }
 348
 349 static void separate_git_dir(const char *git_dir, const char *git_link)
 350 {
 351         struct stat st;
 352
 353         if (!stat(git_link, &st)) {
 354                 const char *src;
 355
 356                 if (S_ISREG(st.st_mode))
 357                         src = read_gitfile(git_link);
 358                 else if (S_ISDIR(st.st_mode))
 359                         src = git_link;
 360                 else
 361                         die(_("unable to handle file type %d"), (int)st.st_mode);
 362
 363                 if (rename(src, git_dir))
 364                         die_errno(_("unable to move %s to %s"), src, git_dir);
 365                 repair_worktrees(NULL, NULL);
 366         }
 367
 368         write_file(git_link, "gitdir: %s", git_dir);
 369 }
 370
 371 static void validate_hash_algorithm(struct repository_format *repo_fmt, int hash)
 372 {
 373         const char *env = getenv(GIT_DEFAULT_HASH_ENVIRONMENT);
 374         /*
 375          * If we already have an initialized repo, don't allow the user to
 376          * specify a different algorithm, as that could cause corruption.
 377          * Otherwise, if the user has specified one on the command line, use it.
 378          */
 379         if (repo_fmt->version >= 0 && hash != GIT_HASH_UNKNOWN && hash != repo_fmt->hash_algo)
 380                 die(_("attempt to reinitialize repository with different hash"));
 381         else if (hash != GIT_HASH_UNKNOWN)
 382                 repo_fmt->hash_algo = hash;
 383         else if (env) {
 384                 int env_algo = hash_algo_by_name(env);
 385                 if (env_algo == GIT_HASH_UNKNOWN)
 386                         die(_("unknown hash algorithm '%s'"), env);
 387                 repo_fmt->hash_algo = env_algo;
 388         }
 389 }
 390
 391 int init_db(const char *git_dir, const char *real_git_dir,
 392             const char *template_dir, int hash, const char *initial_branch,
 393             unsigned int flags)
 394 {
 395         int reinit;
 396         int exist_ok = flags & INIT_DB_EXIST_OK;
 397         char *original_git_dir = real_pathdup(git_dir, 1);
 398         struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT;
 399
 400         if (real_git_dir) {
 401                 struct stat st;
 402
 403                 if (!exist_ok && !stat(git_dir, &st))
 404                         die(_("%s already exists"), git_dir);
 405
 406                 if (!exist_ok && !stat(real_git_dir, &st))
 407                         die(_("%s already exists"), real_git_dir);
 408
 409                 set_git_dir(real_git_dir, 1);
 410                 git_dir = get_git_dir();
 411                 separate_git_dir(git_dir, original_git_dir);
 412         }
 413         else {
 414                 set_git_dir(git_dir, 1);
 415                 git_dir = get_git_dir();
 416         }
 417         startup_info->have_repository = 1;
 418
 419         /* Ensure `core.hidedotfiles` is processed */
 420         git_config(platform_core_config, NULL);
 421
 422         safe_create_dir(git_dir, 0);
 423
 424         init_is_bare_repository = is_bare_repository();
 425
 426         /* Check to see if the repository version is right.
 427          * Note that a newly created repository does not have
 428          * config file, so this will not fail.  What we are catching
 429          * is an attempt to reinitialize new repository with an old tool.
 430          */
 431         check_repository_format(&repo_fmt);
 432
 433         validate_hash_algorithm(&repo_fmt, hash);
 434
 435         reinit = create_default_files(template_dir, original_git_dir,
 436                                       initial_branch, &repo_fmt,
 437                                       flags & INIT_DB_QUIET);
 438         if (reinit && initial_branch)
 439                 warning(_("re-init: ignored --initial-branch=%s"),
 440                         initial_branch);
 441
 442         create_object_directory();
 443
 444         if (get_shared_repository()) {
 445                 char buf[10];
 446                 /* We do not spell "group" and such, so that
 447                  * the configuration can be read by older version
 448                  * of git. Note, we use octal numbers for new share modes,
 449                  * and compatibility values for PERM_GROUP and
 450                  * PERM_EVERYBODY.
 451                  */
 452                 if (get_shared_repository() < 0)
 453                         /* force to the mode value */
 454                         xsnprintf(buf, sizeof(buf), "0%o", -get_shared_repository());
 455                 else if (get_shared_repository() == PERM_GROUP)
 456                         xsnprintf(buf, sizeof(buf), "%d", OLD_PERM_GROUP);
 457                 else if (get_shared_repository() == PERM_EVERYBODY)
 458                         xsnprintf(buf, sizeof(buf), "%d", OLD_PERM_EVERYBODY);
 459                 else
 460                         BUG("invalid value for shared_repository");
 461                 git_config_set("core.sharedrepository", buf);
 462                 git_config_set("receive.denyNonFastforwards", "true");
 463         }
 464
 465         if (!(flags & INIT_DB_QUIET)) {
 466                 int len = strlen(git_dir);
 467
 468                 if (reinit)
 469                         printf(get_shared_repository()
 470                                ? _("Reinitialized existing shared Git repository in %s%s\n")
 471                                : _("Reinitialized existing Git repository in %s%s\n"),
 472                                git_dir, len && git_dir[len-1] != '/' ? "/" : "");
 473                 else
 474                         printf(get_shared_repository()
 475                                ? _("Initialized empty shared Git repository in %s%s\n")
 476                                : _("Initialized empty Git repository in %s%s\n"),
 477                                git_dir, len && git_dir[len-1] != '/' ? "/" : "");
 478         }
 479
 480         free(original_git_dir);
 481         return 0;
 482 }
 483
 484 static int guess_repository_type(const char *git_dir)
 485 {
 486         const char *slash;
 487         char *cwd;
 488         int cwd_is_git_dir;
 489
 490         /*
 491          * "GIT_DIR=. git init" is always bare.
 492          * "GIT_DIR=`pwd` git init" too.
 493          */
 494         if (!strcmp(".", git_dir))
 495                 return 1;
 496         cwd = xgetcwd();
 497         cwd_is_git_dir = !strcmp(git_dir, cwd);
 498         free(cwd);
 499         if (cwd_is_git_dir)
 500                 return 1;
 501         /*
 502          * "GIT_DIR=.git or GIT_DIR=something/.git is usually not.
 503          */
 504         if (!strcmp(git_dir, ".git"))
 505                 return 0;
 506         slash = strrchr(git_dir, '/');
 507         if (slash && !strcmp(slash, "/.git"))
 508                 return 0;
 509
 510         /*
 511          * Otherwise it is often bare.  At this point
 512          * we are just guessing.
 513          */
 514         return 1;
 515 }
 516
 517 static int shared_callback(const struct option *opt, const char *arg, int unset)
 518 {
 519         BUG_ON_OPT_NEG(unset);
 520         *((int *) opt->value) = (arg) ? git_config_perm("arg", arg) : PERM_GROUP;
 521         return 0;
 522 }
 523
 524 static const char *const init_db_usage[] = {
 525         N_("git init [-q | --quiet] [--bare] [--template=<template-directory>]\n"
 526            "         [--separate-git-dir <git-dir>] [--object-format=<format>]\n"
 527            "         [-b <branch-name> | --initial-branch=<branch-name>]\n"
 528            "         [--shared[=<permissions>]] [<directory>]"),
 529         NULL
 530 };
 531
 532 /*
 533  * If you want to, you can share the DB area with any number of branches.
 534  * That has advantages: you can save space by sharing all the SHA1 objects.
 535  * On the other hand, it might just make lookup slower and messier. You
 536  * be the judge.  The default case is to have one DB per managed directory.
 537  */
 538 int cmd_init_db(int argc, const char **argv, const char *prefix)
 539 {
 540         const char *git_dir;
 541         const char *real_git_dir = NULL;
 542         const char *work_tree;
 543         const char *template_dir = NULL;
 544         unsigned int flags = 0;
 545         const char *object_format = NULL;
 546         const char *initial_branch = NULL;
 547         int hash_algo = GIT_HASH_UNKNOWN;
 548         const struct option init_db_options[] = {
 549                 OPT_STRING(0, "template", &template_dir, N_("template-directory"),
 550                                 N_("directory from which templates will be used")),
 551                 OPT_SET_INT(0, "bare", &is_bare_repository_cfg,
 552                                 N_("create a bare repository"), 1),
 553                 { OPTION_CALLBACK, 0, "shared", &init_shared_repository,
 554                         N_("permissions"),
 555                         N_("specify that the git repository is to be shared amongst several users"),
 556                         PARSE_OPT_OPTARG | PARSE_OPT_NONEG, shared_callback, 0},
 557                 OPT_BIT('q', "quiet", &flags, N_("be quiet"), INIT_DB_QUIET),
 558                 OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
 559                            N_("separate git dir from working tree")),
 560                 OPT_STRING('b', "initial-branch", &initial_branch, N_("name"),
 561                            N_("override the name of the initial branch")),
 562                 OPT_STRING(0, "object-format", &object_format, N_("hash"),
 563                            N_("specify the hash algorithm to use")),
 564                 OPT_END()
 565         };
 566
 567         argc = parse_options(argc, argv, prefix, init_db_options, init_db_usage, 0);
 568
 569         if (real_git_dir && is_bare_repository_cfg == 1)
 570                 die(_("options '%s' and '%s' cannot be used together"), "--separate-git-dir", "--bare");
 571
 572         if (real_git_dir && !is_absolute_path(real_git_dir))
 573                 real_git_dir = real_pathdup(real_git_dir, 1);
 574
 575         if (template_dir && *template_dir && !is_absolute_path(template_dir)) {
 576                 template_dir = absolute_pathdup(template_dir);
 577                 UNLEAK(template_dir);
 578         }
 579
 580         if (argc == 1) {
 581                 int mkdir_tried = 0;
 582         retry:
 583                 if (chdir(argv[0]) < 0) {
 584                         if (!mkdir_tried) {
 585                                 int saved;
 586                                 /*
 587                                  * At this point we haven't read any configuration,
 588                                  * and we know shared_repository should always be 0;
 589                                  * but just in case we play safe.
 590                                  */
 591                                 saved = get_shared_repository();
 592                                 set_shared_repository(0);
 593                                 switch (safe_create_leading_directories_const(argv[0])) {
 594                                 case SCLD_OK:
 595                                 case SCLD_PERMS:
 596                                         break;
 597                                 case SCLD_EXISTS:
 598                                         errno = EEXIST;
 599                                         /* fallthru */
 600                                 default:
 601                                         die_errno(_("cannot mkdir %s"), argv[0]);
 602                                         break;
 603                                 }
 604                                 set_shared_repository(saved);
 605                                 if (mkdir(argv[0], 0777) < 0)
 606                                         die_errno(_("cannot mkdir %s"), argv[0]);
 607                                 mkdir_tried = 1;
 608                                 goto retry;
 609                         }
 610                         die_errno(_("cannot chdir to %s"), argv[0]);
 611                 }
 612         } else if (0 < argc) {
 613                 usage(init_db_usage[0]);
 614         }
 615         if (is_bare_repository_cfg == 1) {
 616                 char *cwd = xgetcwd();
 617                 setenv(GIT_DIR_ENVIRONMENT, cwd, argc > 0);
 618                 free(cwd);
 619         }
 620
 621         if (object_format) {
 622                 hash_algo = hash_algo_by_name(object_format);
 623                 if (hash_algo == GIT_HASH_UNKNOWN)
 624                         die(_("unknown hash algorithm '%s'"), object_format);
 625         }
 626
 627         if (init_shared_repository != -1)
 628                 set_shared_repository(init_shared_repository);
 629
 630         /*
 631          * GIT_WORK_TREE makes sense only in conjunction with GIT_DIR
 632          * without --bare.  Catch the error early.
 633          */
 634         git_dir = xstrdup_or_null(getenv(GIT_DIR_ENVIRONMENT));
 635         work_tree = xstrdup_or_null(getenv(GIT_WORK_TREE_ENVIRONMENT));
 636         if ((!git_dir || is_bare_repository_cfg == 1) && work_tree)
 637                 die(_("%s (or --work-tree=<directory>) not allowed without "
 638                           "specifying %s (or --git-dir=<directory>)"),
 639                     GIT_WORK_TREE_ENVIRONMENT,
 640                     GIT_DIR_ENVIRONMENT);
 641
 642         /*
 643          * Set up the default .git directory contents
 644          */
 645         if (!git_dir)
 646                 git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
 647
 648         /*
 649          * When --separate-git-dir is used inside a linked worktree, take
 650          * care to ensure that the common .git/ directory is relocated, not
 651          * the worktree-specific .git/worktrees/<id>/ directory.
 652          */
 653         if (real_git_dir) {
 654                 int err;
 655                 const char *p;
 656                 struct strbuf sb = STRBUF_INIT;
 657
 658                 p = read_gitfile_gently(git_dir, &err);
 659                 if (p && get_common_dir(&sb, p)) {
 660                         struct strbuf mainwt = STRBUF_INIT;
 661
 662                         strbuf_addbuf(&mainwt, &sb);
 663                         strbuf_strip_suffix(&mainwt, "/.git");
 664                         if (chdir(mainwt.buf) < 0)
 665                                 die_errno(_("cannot chdir to %s"), mainwt.buf);
 666                         strbuf_release(&mainwt);
 667                         git_dir = strbuf_detach(&sb, NULL);
 668                 }
 669                 strbuf_release(&sb);
 670         }
 671
 672         if (is_bare_repository_cfg < 0)
 673                 is_bare_repository_cfg = guess_repository_type(git_dir);
 674
 675         if (!is_bare_repository_cfg) {
 676                 const char *git_dir_parent = strrchr(git_dir, '/');
 677                 if (git_dir_parent) {
 678                         char *rel = xstrndup(git_dir, git_dir_parent - git_dir);
 679                         git_work_tree_cfg = real_pathdup(rel, 1);
 680                         free(rel);
 681                 }
 682                 if (!git_work_tree_cfg)
 683                         git_work_tree_cfg = xgetcwd();
 684                 if (work_tree)
 685                         set_git_work_tree(work_tree);
 686                 else
 687                         set_git_work_tree(git_work_tree_cfg);
 688                 if (access(get_git_work_tree(), X_OK))
 689                         die_errno (_("Cannot access work tree '%s'"),
 690                                    get_git_work_tree());
 691         }
 692         else {
 693                 if (real_git_dir)
 694                         die(_("--separate-git-dir incompatible with bare repository"));
 695                 if (work_tree)
 696                         set_git_work_tree(work_tree);
 697         }
 698
 699         UNLEAK(real_git_dir);
 700         UNLEAK(git_dir);
 701         UNLEAK(work_tree);
 702
 703         flags |= INIT_DB_EXIST_OK;
 704         return init_db(git_dir, real_git_dir, template_dir, hash_algo,
 705                        initial_branch, flags);
 706 }