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 "path.h"
  18 #include "setup.h"
  19 #include "worktree.h"
  20 #include "wrapper.h"
  21
  22 #ifndef DEFAULT_GIT_TEMPLATE_DIR
  23 #define DEFAULT_GIT_TEMPLATE_DIR "/usr/share/git-core/templates"
  24 #endif
  25
  26 #ifdef NO_TRUSTABLE_FILEMODE
  27 #define TEST_FILEMODE 0
  28 #else
  29 #define TEST_FILEMODE 1
  30 #endif
  31
  32 #define GIT_DEFAULT_HASH_ENVIRONMENT "GIT_DEFAULT_HASH"
  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 prev_bare_repository,
 200                                 int init_shared_repository,
 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         if (init_shared_repository != -1)
 234                 set_shared_repository(init_shared_repository);
 235         /*
 236          * TODO: heed core.bare from config file in templates if no
 237          *       command-line override given
 238          */
 239         is_bare_repository_cfg = prev_bare_repository || !work_tree;
 240         /* TODO (continued):
 241          *
 242          * Unfortunately, the line above is equivalent to
 243          *    is_bare_repository_cfg = !work_tree;
 244          * which ignores the config entirely even if no `--[no-]bare`
 245          * command line option was present.
 246          *
 247          * To see why, note that before this function, there was this call:
 248          *    prev_bare_repository = is_bare_repository()
 249          * expanding the right hand side:
 250          *                 = is_bare_repository_cfg && !get_git_work_tree()
 251          *                 = is_bare_repository_cfg && !work_tree
 252          * note that the last simplification above is valid because nothing
 253          * calls repo_init() or set_git_work_tree() between any of the
 254          * relevant calls in the code, and thus the !get_git_work_tree()
 255          * calls will return the same result each time.  So, what we are
 256          * interested in computing is the right hand side of the line of
 257          * code just above this comment:
 258          *     prev_bare_repository || !work_tree
 259          *        = is_bare_repository_cfg && !work_tree || !work_tree
 260          *        = !work_tree
 261          * because "A && !B || !B == !B" for all boolean values of A & B.
 262          */
 263
 264         /*
 265          * We would have created the above under user's umask -- under
 266          * shared-repository settings, we would need to fix them up.
 267          */
 268         if (get_shared_repository()) {
 269                 adjust_shared_perm(get_git_dir());
 270         }
 271
 272         /*
 273          * We need to create a "refs" dir in any case so that older
 274          * versions of git can tell that this is a repository.
 275          */
 276         safe_create_dir(git_path("refs"), 1);
 277         adjust_shared_perm(git_path("refs"));
 278
 279         if (refs_init_db(&err))
 280                 die("failed to set up refs db: %s", err.buf);
 281
 282         /*
 283          * Point the HEAD symref to the initial branch with if HEAD does
 284          * not yet exist.
 285          */
 286         path = git_path_buf(&buf, "HEAD");
 287         reinit = (!access(path, R_OK)
 288                   || readlink(path, junk, sizeof(junk)-1) != -1);
 289         if (!reinit) {
 290                 char *ref;
 291
 292                 if (!initial_branch)
 293                         initial_branch = git_default_branch_name(quiet);
 294
 295                 ref = xstrfmt("refs/heads/%s", initial_branch);
 296                 if (check_refname_format(ref, 0) < 0)
 297                         die(_("invalid initial branch name: '%s'"),
 298                             initial_branch);
 299
 300                 if (create_symref("HEAD", ref, NULL) < 0)
 301                         exit(1);
 302                 free(ref);
 303         }
 304
 305         initialize_repository_version(fmt->hash_algo, 0);
 306
 307         /* Check filemode trustability */
 308         path = git_path_buf(&buf, "config");
 309         filemode = TEST_FILEMODE;
 310         if (TEST_FILEMODE && !lstat(path, &st1)) {
 311                 struct stat st2;
 312                 filemode = (!chmod(path, st1.st_mode ^ S_IXUSR) &&
 313                                 !lstat(path, &st2) &&
 314                                 st1.st_mode != st2.st_mode &&
 315                                 !chmod(path, st1.st_mode));
 316                 if (filemode && !reinit && (st1.st_mode & S_IXUSR))
 317                         filemode = 0;
 318         }
 319         git_config_set("core.filemode", filemode ? "true" : "false");
 320
 321         if (is_bare_repository())
 322                 git_config_set("core.bare", "true");
 323         else {
 324                 git_config_set("core.bare", "false");
 325                 /* allow template config file to override the default */
 326                 if (log_all_ref_updates == LOG_REFS_UNSET)
 327                         git_config_set("core.logallrefupdates", "true");
 328                 if (needs_work_tree_config(original_git_dir, work_tree))
 329                         git_config_set("core.worktree", work_tree);
 330         }
 331
 332         if (!reinit) {
 333                 /* Check if symlink is supported in the work tree */
 334                 path = git_path_buf(&buf, "tXXXXXX");
 335                 if (!close(xmkstemp(path)) &&
 336                     !unlink(path) &&
 337                     !symlink("testing", path) &&
 338                     !lstat(path, &st1) &&
 339                     S_ISLNK(st1.st_mode))
 340                         unlink(path); /* good */
 341                 else
 342                         git_config_set("core.symlinks", "false");
 343
 344                 /* Check if the filesystem is case-insensitive */
 345                 path = git_path_buf(&buf, "CoNfIg");
 346                 if (!access(path, F_OK))
 347                         git_config_set("core.ignorecase", "true");
 348                 probe_utf8_pathname_composition();
 349         }
 350
 351         strbuf_release(&buf);
 352         return reinit;
 353 }
 354
 355 static void create_object_directory(void)
 356 {
 357         struct strbuf path = STRBUF_INIT;
 358         size_t baselen;
 359
 360         strbuf_addstr(&path, get_object_directory());
 361         baselen = path.len;
 362
 363         safe_create_dir(path.buf, 1);
 364
 365         strbuf_setlen(&path, baselen);
 366         strbuf_addstr(&path, "/pack");
 367         safe_create_dir(path.buf, 1);
 368
 369         strbuf_setlen(&path, baselen);
 370         strbuf_addstr(&path, "/info");
 371         safe_create_dir(path.buf, 1);
 372
 373         strbuf_release(&path);
 374 }
 375
 376 static void separate_git_dir(const char *git_dir, const char *git_link)
 377 {
 378         struct stat st;
 379
 380         if (!stat(git_link, &st)) {
 381                 const char *src;
 382
 383                 if (S_ISREG(st.st_mode))
 384                         src = read_gitfile(git_link);
 385                 else if (S_ISDIR(st.st_mode))
 386                         src = git_link;
 387                 else
 388                         die(_("unable to handle file type %d"), (int)st.st_mode);
 389
 390                 if (rename(src, git_dir))
 391                         die_errno(_("unable to move %s to %s"), src, git_dir);
 392                 repair_worktrees(NULL, NULL);
 393         }
 394
 395         write_file(git_link, "gitdir: %s", git_dir);
 396 }
 397
 398 static void validate_hash_algorithm(struct repository_format *repo_fmt, int hash)
 399 {
 400         const char *env = getenv(GIT_DEFAULT_HASH_ENVIRONMENT);
 401         /*
 402          * If we already have an initialized repo, don't allow the user to
 403          * specify a different algorithm, as that could cause corruption.
 404          * Otherwise, if the user has specified one on the command line, use it.
 405          */
 406         if (repo_fmt->version >= 0 && hash != GIT_HASH_UNKNOWN && hash != repo_fmt->hash_algo)
 407                 die(_("attempt to reinitialize repository with different hash"));
 408         else if (hash != GIT_HASH_UNKNOWN)
 409                 repo_fmt->hash_algo = hash;
 410         else if (env) {
 411                 int env_algo = hash_algo_by_name(env);
 412                 if (env_algo == GIT_HASH_UNKNOWN)
 413                         die(_("unknown hash algorithm '%s'"), env);
 414                 repo_fmt->hash_algo = env_algo;
 415         }
 416 }
 417
 418 int init_db(const char *git_dir, const char *real_git_dir,
 419             const char *template_dir, int hash, const char *initial_branch,
 420             int init_shared_repository, unsigned int flags)
 421 {
 422         int reinit;
 423         int exist_ok = flags & INIT_DB_EXIST_OK;
 424         char *original_git_dir = real_pathdup(git_dir, 1);
 425         struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT;
 426         int prev_bare_repository;
 427
 428         if (real_git_dir) {
 429                 struct stat st;
 430
 431                 if (!exist_ok && !stat(git_dir, &st))
 432                         die(_("%s already exists"), git_dir);
 433
 434                 if (!exist_ok && !stat(real_git_dir, &st))
 435                         die(_("%s already exists"), real_git_dir);
 436
 437                 set_git_dir(real_git_dir, 1);
 438                 git_dir = get_git_dir();
 439                 separate_git_dir(git_dir, original_git_dir);
 440         }
 441         else {
 442                 set_git_dir(git_dir, 1);
 443                 git_dir = get_git_dir();
 444         }
 445         startup_info->have_repository = 1;
 446
 447         /* Ensure `core.hidedotfiles` is processed */
 448         git_config(platform_core_config, NULL);
 449
 450         safe_create_dir(git_dir, 0);
 451
 452         prev_bare_repository = is_bare_repository();
 453
 454         /* Check to see if the repository version is right.
 455          * Note that a newly created repository does not have
 456          * config file, so this will not fail.  What we are catching
 457          * is an attempt to reinitialize new repository with an old tool.
 458          */
 459         check_repository_format(&repo_fmt);
 460
 461         validate_hash_algorithm(&repo_fmt, hash);
 462
 463         reinit = create_default_files(template_dir, original_git_dir,
 464                                       initial_branch, &repo_fmt,
 465                                       prev_bare_repository,
 466                                       init_shared_repository,
 467                                       flags & INIT_DB_QUIET);
 468         if (reinit && initial_branch)
 469                 warning(_("re-init: ignored --initial-branch=%s"),
 470                         initial_branch);
 471
 472         create_object_directory();
 473
 474         if (get_shared_repository()) {
 475                 char buf[10];
 476                 /* We do not spell "group" and such, so that
 477                  * the configuration can be read by older version
 478                  * of git. Note, we use octal numbers for new share modes,
 479                  * and compatibility values for PERM_GROUP and
 480                  * PERM_EVERYBODY.
 481                  */
 482                 if (get_shared_repository() < 0)
 483                         /* force to the mode value */
 484                         xsnprintf(buf, sizeof(buf), "0%o", -get_shared_repository());
 485                 else if (get_shared_repository() == PERM_GROUP)
 486                         xsnprintf(buf, sizeof(buf), "%d", OLD_PERM_GROUP);
 487                 else if (get_shared_repository() == PERM_EVERYBODY)
 488                         xsnprintf(buf, sizeof(buf), "%d", OLD_PERM_EVERYBODY);
 489                 else
 490                         BUG("invalid value for shared_repository");
 491                 git_config_set("core.sharedrepository", buf);
 492                 git_config_set("receive.denyNonFastforwards", "true");
 493         }
 494
 495         if (!(flags & INIT_DB_QUIET)) {
 496                 int len = strlen(git_dir);
 497
 498                 if (reinit)
 499                         printf(get_shared_repository()
 500                                ? _("Reinitialized existing shared Git repository in %s%s\n")
 501                                : _("Reinitialized existing Git repository in %s%s\n"),
 502                                git_dir, len && git_dir[len-1] != '/' ? "/" : "");
 503                 else
 504                         printf(get_shared_repository()
 505                                ? _("Initialized empty shared Git repository in %s%s\n")
 506                                : _("Initialized empty Git repository in %s%s\n"),
 507                                git_dir, len && git_dir[len-1] != '/' ? "/" : "");
 508         }
 509
 510         free(original_git_dir);
 511         return 0;
 512 }
 513
 514 static int guess_repository_type(const char *git_dir)
 515 {
 516         const char *slash;
 517         char *cwd;
 518         int cwd_is_git_dir;
 519
 520         /*
 521          * "GIT_DIR=. git init" is always bare.
 522          * "GIT_DIR=`pwd` git init" too.
 523          */
 524         if (!strcmp(".", git_dir))
 525                 return 1;
 526         cwd = xgetcwd();
 527         cwd_is_git_dir = !strcmp(git_dir, cwd);
 528         free(cwd);
 529         if (cwd_is_git_dir)
 530                 return 1;
 531         /*
 532          * "GIT_DIR=.git or GIT_DIR=something/.git is usually not.
 533          */
 534         if (!strcmp(git_dir, ".git"))
 535                 return 0;
 536         slash = strrchr(git_dir, '/');
 537         if (slash && !strcmp(slash, "/.git"))
 538                 return 0;
 539
 540         /*
 541          * Otherwise it is often bare.  At this point
 542          * we are just guessing.
 543          */
 544         return 1;
 545 }
 546
 547 static int shared_callback(const struct option *opt, const char *arg, int unset)
 548 {
 549         BUG_ON_OPT_NEG(unset);
 550         *((int *) opt->value) = (arg) ? git_config_perm("arg", arg) : PERM_GROUP;
 551         return 0;
 552 }
 553
 554 static const char *const init_db_usage[] = {
 555         N_("git init [-q | --quiet] [--bare] [--template=<template-directory>]\n"
 556            "         [--separate-git-dir <git-dir>] [--object-format=<format>]\n"
 557            "         [-b <branch-name> | --initial-branch=<branch-name>]\n"
 558            "         [--shared[=<permissions>]] [<directory>]"),
 559         NULL
 560 };
 561
 562 /*
 563  * If you want to, you can share the DB area with any number of branches.
 564  * That has advantages: you can save space by sharing all the SHA1 objects.
 565  * On the other hand, it might just make lookup slower and messier. You
 566  * be the judge.  The default case is to have one DB per managed directory.
 567  */
 568 int cmd_init_db(int argc, const char **argv, const char *prefix)
 569 {
 570         const char *git_dir;
 571         const char *real_git_dir = NULL;
 572         const char *work_tree;
 573         const char *template_dir = NULL;
 574         unsigned int flags = 0;
 575         const char *object_format = NULL;
 576         const char *initial_branch = NULL;
 577         int hash_algo = GIT_HASH_UNKNOWN;
 578         int init_shared_repository = -1;
 579         const struct option init_db_options[] = {
 580                 OPT_STRING(0, "template", &template_dir, N_("template-directory"),
 581                                 N_("directory from which templates will be used")),
 582                 OPT_SET_INT(0, "bare", &is_bare_repository_cfg,
 583                                 N_("create a bare repository"), 1),
 584                 { OPTION_CALLBACK, 0, "shared", &init_shared_repository,
 585                         N_("permissions"),
 586                         N_("specify that the git repository is to be shared amongst several users"),
 587                         PARSE_OPT_OPTARG | PARSE_OPT_NONEG, shared_callback, 0},
 588                 OPT_BIT('q', "quiet", &flags, N_("be quiet"), INIT_DB_QUIET),
 589                 OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
 590                            N_("separate git dir from working tree")),
 591                 OPT_STRING('b', "initial-branch", &initial_branch, N_("name"),
 592                            N_("override the name of the initial branch")),
 593                 OPT_STRING(0, "object-format", &object_format, N_("hash"),
 594                            N_("specify the hash algorithm to use")),
 595                 OPT_END()
 596         };
 597
 598         argc = parse_options(argc, argv, prefix, init_db_options, init_db_usage, 0);
 599
 600         if (real_git_dir && is_bare_repository_cfg == 1)
 601                 die(_("options '%s' and '%s' cannot be used together"), "--separate-git-dir", "--bare");
 602
 603         if (real_git_dir && !is_absolute_path(real_git_dir))
 604                 real_git_dir = real_pathdup(real_git_dir, 1);
 605
 606         if (template_dir && *template_dir && !is_absolute_path(template_dir)) {
 607                 template_dir = absolute_pathdup(template_dir);
 608                 UNLEAK(template_dir);
 609         }
 610
 611         if (argc == 1) {
 612                 int mkdir_tried = 0;
 613         retry:
 614                 if (chdir(argv[0]) < 0) {
 615                         if (!mkdir_tried) {
 616                                 int saved;
 617                                 /*
 618                                  * At this point we haven't read any configuration,
 619                                  * and we know shared_repository should always be 0;
 620                                  * but just in case we play safe.
 621                                  */
 622                                 saved = get_shared_repository();
 623                                 set_shared_repository(0);
 624                                 switch (safe_create_leading_directories_const(argv[0])) {
 625                                 case SCLD_OK:
 626                                 case SCLD_PERMS:
 627                                         break;
 628                                 case SCLD_EXISTS:
 629                                         errno = EEXIST;
 630                                         /* fallthru */
 631                                 default:
 632                                         die_errno(_("cannot mkdir %s"), argv[0]);
 633                                         break;
 634                                 }
 635                                 set_shared_repository(saved);
 636                                 if (mkdir(argv[0], 0777) < 0)
 637                                         die_errno(_("cannot mkdir %s"), argv[0]);
 638                                 mkdir_tried = 1;
 639                                 goto retry;
 640                         }
 641                         die_errno(_("cannot chdir to %s"), argv[0]);
 642                 }
 643         } else if (0 < argc) {
 644                 usage(init_db_usage[0]);
 645         }
 646         if (is_bare_repository_cfg == 1) {
 647                 char *cwd = xgetcwd();
 648                 setenv(GIT_DIR_ENVIRONMENT, cwd, argc > 0);
 649                 free(cwd);
 650         }
 651
 652         if (object_format) {
 653                 hash_algo = hash_algo_by_name(object_format);
 654                 if (hash_algo == GIT_HASH_UNKNOWN)
 655                         die(_("unknown hash algorithm '%s'"), object_format);
 656         }
 657
 658         if (init_shared_repository != -1)
 659                 set_shared_repository(init_shared_repository);
 660
 661         /*
 662          * GIT_WORK_TREE makes sense only in conjunction with GIT_DIR
 663          * without --bare.  Catch the error early.
 664          */
 665         git_dir = xstrdup_or_null(getenv(GIT_DIR_ENVIRONMENT));
 666         work_tree = xstrdup_or_null(getenv(GIT_WORK_TREE_ENVIRONMENT));
 667         if ((!git_dir || is_bare_repository_cfg == 1) && work_tree)
 668                 die(_("%s (or --work-tree=<directory>) not allowed without "
 669                           "specifying %s (or --git-dir=<directory>)"),
 670                     GIT_WORK_TREE_ENVIRONMENT,
 671                     GIT_DIR_ENVIRONMENT);
 672
 673         /*
 674          * Set up the default .git directory contents
 675          */
 676         if (!git_dir)
 677                 git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
 678
 679         /*
 680          * When --separate-git-dir is used inside a linked worktree, take
 681          * care to ensure that the common .git/ directory is relocated, not
 682          * the worktree-specific .git/worktrees/<id>/ directory.
 683          */
 684         if (real_git_dir) {
 685                 int err;
 686                 const char *p;
 687                 struct strbuf sb = STRBUF_INIT;
 688
 689                 p = read_gitfile_gently(git_dir, &err);
 690                 if (p && get_common_dir(&sb, p)) {
 691                         struct strbuf mainwt = STRBUF_INIT;
 692
 693                         strbuf_addbuf(&mainwt, &sb);
 694                         strbuf_strip_suffix(&mainwt, "/.git");
 695                         if (chdir(mainwt.buf) < 0)
 696                                 die_errno(_("cannot chdir to %s"), mainwt.buf);
 697                         strbuf_release(&mainwt);
 698                         git_dir = strbuf_detach(&sb, NULL);
 699                 }
 700                 strbuf_release(&sb);
 701         }
 702
 703         if (is_bare_repository_cfg < 0)
 704                 is_bare_repository_cfg = guess_repository_type(git_dir);
 705
 706         if (!is_bare_repository_cfg) {
 707                 const char *git_dir_parent = strrchr(git_dir, '/');
 708                 if (git_dir_parent) {
 709                         char *rel = xstrndup(git_dir, git_dir_parent - git_dir);
 710                         git_work_tree_cfg = real_pathdup(rel, 1);
 711                         free(rel);
 712                 }
 713                 if (!git_work_tree_cfg)
 714                         git_work_tree_cfg = xgetcwd();
 715                 if (work_tree)
 716                         set_git_work_tree(work_tree);
 717                 else
 718                         set_git_work_tree(git_work_tree_cfg);
 719                 if (access(get_git_work_tree(), X_OK))
 720                         die_errno (_("Cannot access work tree '%s'"),
 721                                    get_git_work_tree());
 722         }
 723         else {
 724                 if (real_git_dir)
 725                         die(_("--separate-git-dir incompatible with bare repository"));
 726                 if (work_tree)
 727                         set_git_work_tree(work_tree);
 728         }
 729
 730         UNLEAK(real_git_dir);
 731         UNLEAK(git_dir);
 732         UNLEAK(work_tree);
 733
 734         flags |= INIT_DB_EXIST_OK;
 735         return init_db(git_dir, real_git_dir, template_dir, hash_algo,
 736                        initial_branch, init_shared_repository, flags);
 737 }