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 int init_is_bare_repository = 0;
  35 static int init_shared_repository = -1;
  36
  37 static void copy_templates_1(struct strbuf *path, struct strbuf *template_path,
  38                              DIR *dir)
  39 {
  40         size_t path_baselen = path->len;
  41         size_t template_baselen = template_path->len;
  42         struct dirent *de;
  43
  44         /* Note: if ".git/hooks" file exists in the repository being
  45          * re-initialized, /etc/core-git/templates/hooks/update would
  46          * cause "git init" to fail here.  I think this is sane but
  47          * it means that the set of templates we ship by default, along
  48          * with the way the namespace under .git/ is organized, should
  49          * be really carefully chosen.
  50          */
  51         safe_create_dir(path->buf, 1);
  52         while ((de = readdir(dir)) != NULL) {
  53                 struct stat st_git, st_template;
  54                 int exists = 0;
  55
  56                 strbuf_setlen(path, path_baselen);
  57                 strbuf_setlen(template_path, template_baselen);
  58
  59                 if (de->d_name[0] == '.')
  60                         continue;
  61                 strbuf_addstr(path, de->d_name);
  62                 strbuf_addstr(template_path, de->d_name);
  63                 if (lstat(path->buf, &st_git)) {
  64                         if (errno != ENOENT)
  65                                 die_errno(_("cannot stat '%s'"), path->buf);
  66                 }
  67                 else
  68                         exists = 1;
  69
  70                 if (lstat(template_path->buf, &st_template))
  71                         die_errno(_("cannot stat template '%s'"), template_path->buf);
  72
  73                 if (S_ISDIR(st_template.st_mode)) {
  74                         DIR *subdir = opendir(template_path->buf);
  75                         if (!subdir)
  76                                 die_errno(_("cannot opendir '%s'"), template_path->buf);
  77                         strbuf_addch(path, '/');
  78                         strbuf_addch(template_path, '/');
  79                         copy_templates_1(path, template_path, subdir);
  80                         closedir(subdir);
  81                 }
  82                 else if (exists)
  83                         continue;
  84                 else if (S_ISLNK(st_template.st_mode)) {
  85                         struct strbuf lnk = STRBUF_INIT;
  86                         if (strbuf_readlink(&lnk, template_path->buf,
  87                                             st_template.st_size) < 0)
  88                                 die_errno(_("cannot readlink '%s'"), template_path->buf);
  89                         if (symlink(lnk.buf, path->buf))
  90                                 die_errno(_("cannot symlink '%s' '%s'"),
  91                                           lnk.buf, path->buf);
  92                         strbuf_release(&lnk);
  93                 }
  94                 else if (S_ISREG(st_template.st_mode)) {
  95                         if (copy_file(path->buf, template_path->buf, st_template.st_mode))
  96                                 die_errno(_("cannot copy '%s' to '%s'"),
  97                                           template_path->buf, path->buf);
  98                 }
  99                 else
 100                         error(_("ignoring template %s"), template_path->buf);
 101         }
 102 }
 103
 104 static void copy_templates(const char *template_dir, const char *init_template_dir)
 105 {
 106         struct strbuf path = STRBUF_INIT;
 107         struct strbuf template_path = STRBUF_INIT;
 108         size_t template_len;
 109         struct repository_format template_format = REPOSITORY_FORMAT_INIT;
 110         struct strbuf err = STRBUF_INIT;
 111         DIR *dir;
 112         char *to_free = NULL;
 113
 114         if (!template_dir)
 115                 template_dir = getenv(TEMPLATE_DIR_ENVIRONMENT);
 116         if (!template_dir)
 117                 template_dir = init_template_dir;
 118         if (!template_dir)
 119                 template_dir = to_free = system_path(DEFAULT_GIT_TEMPLATE_DIR);
 120         if (!template_dir[0]) {
 121                 free(to_free);
 122                 return;
 123         }
 124
 125         strbuf_addstr(&template_path, template_dir);
 126         strbuf_complete(&template_path, '/');
 127         template_len = template_path.len;
 128
 129         dir = opendir(template_path.buf);
 130         if (!dir) {
 131                 warning(_("templates not found in %s"), template_dir);
 132                 goto free_return;
 133         }
 134
 135         /* Make sure that template is from the correct vintage */
 136         strbuf_addstr(&template_path, "config");
 137         read_repository_format(&template_format, template_path.buf);
 138         strbuf_setlen(&template_path, template_len);
 139
 140         /*
 141          * No mention of version at all is OK, but anything else should be
 142          * verified.
 143          */
 144         if (template_format.version >= 0 &&
 145             verify_repository_format(&template_format, &err) < 0) {
 146                 warning(_("not copying templates from '%s': %s"),
 147                           template_dir, err.buf);
 148                 strbuf_release(&err);
 149                 goto close_free_return;
 150         }
 151
 152         strbuf_addstr(&path, get_git_common_dir());
 153         strbuf_complete(&path, '/');
 154         copy_templates_1(&path, &template_path, dir);
 155 close_free_return:
 156         closedir(dir);
 157 free_return:
 158         free(to_free);
 159         strbuf_release(&path);
 160         strbuf_release(&template_path);
 161         clear_repository_format(&template_format);
 162 }
 163
 164 /*
 165  * If the git_dir is not directly inside the working tree, then git will not
 166  * find it by default, and we need to set the worktree explicitly.
 167  */
 168 static int needs_work_tree_config(const char *git_dir, const char *work_tree)
 169 {
 170         if (!strcmp(work_tree, "/") && !strcmp(git_dir, "/.git"))
 171                 return 0;
 172         if (skip_prefix(git_dir, work_tree, &git_dir) &&
 173             !strcmp(git_dir, "/.git"))
 174                 return 0;
 175         return 1;
 176 }
 177
 178 void initialize_repository_version(int hash_algo, int reinit)
 179 {
 180         char repo_version_string[10];
 181         int repo_version = GIT_REPO_VERSION;
 182
 183         if (hash_algo != GIT_HASH_SHA1)
 184                 repo_version = GIT_REPO_VERSION_READ;
 185
 186         /* This forces creation of new config file */
 187         xsnprintf(repo_version_string, sizeof(repo_version_string),
 188                   "%d", repo_version);
 189         git_config_set("core.repositoryformatversion", repo_version_string);
 190
 191         if (hash_algo != GIT_HASH_SHA1)
 192                 git_config_set("extensions.objectformat",
 193                                hash_algos[hash_algo].name);
 194         else if (reinit)
 195                 git_config_set_gently("extensions.objectformat", NULL);
 196 }
 197
 198 static int create_default_files(const char *template_path,
 199                                 const char *original_git_dir,
 200                                 const char *initial_branch,
 201                                 const struct repository_format *fmt,
 202                                 int quiet)
 203 {
 204         struct stat st1;
 205         struct strbuf buf = STRBUF_INIT;
 206         char *path;
 207         char junk[2];
 208         int reinit;
 209         int filemode;
 210         struct strbuf err = STRBUF_INIT;
 211         const char *init_template_dir = NULL;
 212         const char *work_tree = get_git_work_tree();
 213
 214         /*
 215          * First copy the templates -- we might have the default
 216          * config file there, in which case we would want to read
 217          * from it after installing.
 218          *
 219          * Before reading that config, we also need to clear out any cached
 220          * values (since we've just potentially changed what's available on
 221          * disk).
 222          */
 223         git_config_get_pathname("init.templatedir", &init_template_dir);
 224         copy_templates(template_path, init_template_dir);
 225         free((char *)init_template_dir);
 226         git_config_clear();
 227         reset_shared_repository();
 228         git_config(git_default_config, NULL);
 229
 230         /*
 231          * We must make sure command-line options continue to override any
 232          * values we might have just re-read from the config.
 233          */
 234         is_bare_repository_cfg = init_is_bare_repository || !work_tree;
 235         if (init_shared_repository != -1)
 236                 set_shared_repository(init_shared_repository);
 237
 238         /*
 239          * We would have created the above under user's umask -- under
 240          * shared-repository settings, we would need to fix them up.
 241          */
 242         if (get_shared_repository()) {
 243                 adjust_shared_perm(get_git_dir());
 244         }
 245
 246         /*
 247          * We need to create a "refs" dir in any case so that older
 248          * versions of git can tell that this is a repository.
 249          */
 250         safe_create_dir(git_path("refs"), 1);
 251         adjust_shared_perm(git_path("refs"));
 252
 253         if (refs_init_db(&err))
 254                 die("failed to set up refs db: %s", err.buf);
 255
 256         /*
 257          * Point the HEAD symref to the initial branch with if HEAD does
 258          * not yet exist.
 259          */
 260         path = git_path_buf(&buf, "HEAD");
 261         reinit = (!access(path, R_OK)
 262                   || readlink(path, junk, sizeof(junk)-1) != -1);
 263         if (!reinit) {
 264                 char *ref;
 265
 266                 if (!initial_branch)
 267                         initial_branch = git_default_branch_name(quiet);
 268
 269                 ref = xstrfmt("refs/heads/%s", initial_branch);
 270                 if (check_refname_format(ref, 0) < 0)
 271                         die(_("invalid initial branch name: '%s'"),
 272                             initial_branch);
 273
 274                 if (create_symref("HEAD", ref, NULL) < 0)
 275                         exit(1);
 276                 free(ref);
 277         }
 278
 279         initialize_repository_version(fmt->hash_algo, 0);
 280
 281         /* Check filemode trustability */
 282         path = git_path_buf(&buf, "config");
 283         filemode = TEST_FILEMODE;
 284         if (TEST_FILEMODE && !lstat(path, &st1)) {
 285                 struct stat st2;
 286                 filemode = (!chmod(path, st1.st_mode ^ S_IXUSR) &&
 287                                 !lstat(path, &st2) &&
 288                                 st1.st_mode != st2.st_mode &&
 289                                 !chmod(path, st1.st_mode));
 290                 if (filemode && !reinit && (st1.st_mode & S_IXUSR))
 291                         filemode = 0;
 292         }
 293         git_config_set("core.filemode", filemode ? "true" : "false");
 294
 295         if (is_bare_repository())
 296                 git_config_set("core.bare", "true");
 297         else {
 298                 git_config_set("core.bare", "false");
 299                 /* allow template config file to override the default */
 300                 if (log_all_ref_updates == LOG_REFS_UNSET)
 301                         git_config_set("core.logallrefupdates", "true");
 302                 if (needs_work_tree_config(original_git_dir, work_tree))
 303                         git_config_set("core.worktree", work_tree);
 304         }
 305
 306         if (!reinit) {
 307                 /* Check if symlink is supported in the work tree */
 308                 path = git_path_buf(&buf, "tXXXXXX");
 309                 if (!close(xmkstemp(path)) &&
 310                     !unlink(path) &&
 311                     !symlink("testing", path) &&
 312                     !lstat(path, &st1) &&
 313                     S_ISLNK(st1.st_mode))
 314                         unlink(path); /* good */
 315                 else
 316                         git_config_set("core.symlinks", "false");
 317
 318                 /* Check if the filesystem is case-insensitive */
 319                 path = git_path_buf(&buf, "CoNfIg");
 320                 if (!access(path, F_OK))
 321                         git_config_set("core.ignorecase", "true");
 322                 probe_utf8_pathname_composition();
 323         }
 324
 325         strbuf_release(&buf);
 326         return reinit;
 327 }
 328
 329 static void create_object_directory(void)
 330 {
 331         struct strbuf path = STRBUF_INIT;
 332         size_t baselen;
 333
 334         strbuf_addstr(&path, get_object_directory());
 335         baselen = path.len;
 336
 337         safe_create_dir(path.buf, 1);
 338
 339         strbuf_setlen(&path, baselen);
 340         strbuf_addstr(&path, "/pack");
 341         safe_create_dir(path.buf, 1);
 342
 343         strbuf_setlen(&path, baselen);
 344         strbuf_addstr(&path, "/info");
 345         safe_create_dir(path.buf, 1);
 346
 347         strbuf_release(&path);
 348 }
 349
 350 static void separate_git_dir(const char *git_dir, const char *git_link)
 351 {
 352         struct stat st;
 353
 354         if (!stat(git_link, &st)) {
 355                 const char *src;
 356
 357                 if (S_ISREG(st.st_mode))
 358                         src = read_gitfile(git_link);
 359                 else if (S_ISDIR(st.st_mode))
 360                         src = git_link;
 361                 else
 362                         die(_("unable to handle file type %d"), (int)st.st_mode);
 363
 364                 if (rename(src, git_dir))
 365                         die_errno(_("unable to move %s to %s"), src, git_dir);
 366                 repair_worktrees(NULL, NULL);
 367         }
 368
 369         write_file(git_link, "gitdir: %s", git_dir);
 370 }
 371
 372 static void validate_hash_algorithm(struct repository_format *repo_fmt, int hash)
 373 {
 374         const char *env = getenv(GIT_DEFAULT_HASH_ENVIRONMENT);
 375         /*
 376          * If we already have an initialized repo, don't allow the user to
 377          * specify a different algorithm, as that could cause corruption.
 378          * Otherwise, if the user has specified one on the command line, use it.
 379          */
 380         if (repo_fmt->version >= 0 && hash != GIT_HASH_UNKNOWN && hash != repo_fmt->hash_algo)
 381                 die(_("attempt to reinitialize repository with different hash"));
 382         else if (hash != GIT_HASH_UNKNOWN)
 383                 repo_fmt->hash_algo = hash;
 384         else if (env) {
 385                 int env_algo = hash_algo_by_name(env);
 386                 if (env_algo == GIT_HASH_UNKNOWN)
 387                         die(_("unknown hash algorithm '%s'"), env);
 388                 repo_fmt->hash_algo = env_algo;
 389         }
 390 }
 391
 392 int init_db(const char *git_dir, const char *real_git_dir,
 393             const char *template_dir, int hash, const char *initial_branch,
 394             unsigned int flags)
 395 {
 396         int reinit;
 397         int exist_ok = flags & INIT_DB_EXIST_OK;
 398         char *original_git_dir = real_pathdup(git_dir, 1);
 399         struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT;
 400
 401         if (real_git_dir) {
 402                 struct stat st;
 403
 404                 if (!exist_ok && !stat(git_dir, &st))
 405                         die(_("%s already exists"), git_dir);
 406
 407                 if (!exist_ok && !stat(real_git_dir, &st))
 408                         die(_("%s already exists"), real_git_dir);
 409
 410                 set_git_dir(real_git_dir, 1);
 411                 git_dir = get_git_dir();
 412                 separate_git_dir(git_dir, original_git_dir);
 413         }
 414         else {
 415                 set_git_dir(git_dir, 1);
 416                 git_dir = get_git_dir();
 417         }
 418         startup_info->have_repository = 1;
 419
 420         /* Ensure `core.hidedotfiles` is processed */
 421         git_config(platform_core_config, NULL);
 422
 423         safe_create_dir(git_dir, 0);
 424
 425         init_is_bare_repository = is_bare_repository();
 426
 427         /* Check to see if the repository version is right.
 428          * Note that a newly created repository does not have
 429          * config file, so this will not fail.  What we are catching
 430          * is an attempt to reinitialize new repository with an old tool.
 431          */
 432         check_repository_format(&repo_fmt);
 433
 434         validate_hash_algorithm(&repo_fmt, hash);
 435
 436         reinit = create_default_files(template_dir, original_git_dir,
 437                                       initial_branch, &repo_fmt,
 438                                       flags & INIT_DB_QUIET);
 439         if (reinit && initial_branch)
 440                 warning(_("re-init: ignored --initial-branch=%s"),
 441                         initial_branch);
 442
 443         create_object_directory();
 444
 445         if (get_shared_repository()) {
 446                 char buf[10];
 447                 /* We do not spell "group" and such, so that
 448                  * the configuration can be read by older version
 449                  * of git. Note, we use octal numbers for new share modes,
 450                  * and compatibility values for PERM_GROUP and
 451                  * PERM_EVERYBODY.
 452                  */
 453                 if (get_shared_repository() < 0)
 454                         /* force to the mode value */
 455                         xsnprintf(buf, sizeof(buf), "0%o", -get_shared_repository());
 456                 else if (get_shared_repository() == PERM_GROUP)
 457                         xsnprintf(buf, sizeof(buf), "%d", OLD_PERM_GROUP);
 458                 else if (get_shared_repository() == PERM_EVERYBODY)
 459                         xsnprintf(buf, sizeof(buf), "%d", OLD_PERM_EVERYBODY);
 460                 else
 461                         BUG("invalid value for shared_repository");
 462                 git_config_set("core.sharedrepository", buf);
 463                 git_config_set("receive.denyNonFastforwards", "true");
 464         }
 465
 466         if (!(flags & INIT_DB_QUIET)) {
 467                 int len = strlen(git_dir);
 468
 469                 if (reinit)
 470                         printf(get_shared_repository()
 471                                ? _("Reinitialized existing shared Git repository in %s%s\n")
 472                                : _("Reinitialized existing Git repository in %s%s\n"),
 473                                git_dir, len && git_dir[len-1] != '/' ? "/" : "");
 474                 else
 475                         printf(get_shared_repository()
 476                                ? _("Initialized empty shared Git repository in %s%s\n")
 477                                : _("Initialized empty Git repository in %s%s\n"),
 478                                git_dir, len && git_dir[len-1] != '/' ? "/" : "");
 479         }
 480
 481         free(original_git_dir);
 482         return 0;
 483 }
 484
 485 static int guess_repository_type(const char *git_dir)
 486 {
 487         const char *slash;
 488         char *cwd;
 489         int cwd_is_git_dir;
 490
 491         /*
 492          * "GIT_DIR=. git init" is always bare.
 493          * "GIT_DIR=`pwd` git init" too.
 494          */
 495         if (!strcmp(".", git_dir))
 496                 return 1;
 497         cwd = xgetcwd();
 498         cwd_is_git_dir = !strcmp(git_dir, cwd);
 499         free(cwd);
 500         if (cwd_is_git_dir)
 501                 return 1;
 502         /*
 503          * "GIT_DIR=.git or GIT_DIR=something/.git is usually not.
 504          */
 505         if (!strcmp(git_dir, ".git"))
 506                 return 0;
 507         slash = strrchr(git_dir, '/');
 508         if (slash && !strcmp(slash, "/.git"))
 509                 return 0;
 510
 511         /*
 512          * Otherwise it is often bare.  At this point
 513          * we are just guessing.
 514          */
 515         return 1;
 516 }
 517
 518 static int shared_callback(const struct option *opt, const char *arg, int unset)
 519 {
 520         BUG_ON_OPT_NEG(unset);
 521         *((int *) opt->value) = (arg) ? git_config_perm("arg", arg) : PERM_GROUP;
 522         return 0;
 523 }
 524
 525 static const char *const init_db_usage[] = {
 526         N_("git init [-q | --quiet] [--bare] [--template=<template-directory>]\n"
 527            "         [--separate-git-dir <git-dir>] [--object-format=<format>]\n"
 528            "         [-b <branch-name> | --initial-branch=<branch-name>]\n"
 529            "         [--shared[=<permissions>]] [<directory>]"),
 530         NULL
 531 };
 532
 533 /*
 534  * If you want to, you can share the DB area with any number of branches.
 535  * That has advantages: you can save space by sharing all the SHA1 objects.
 536  * On the other hand, it might just make lookup slower and messier. You
 537  * be the judge.  The default case is to have one DB per managed directory.
 538  */
 539 int cmd_init_db(int argc, const char **argv, const char *prefix)
 540 {
 541         const char *git_dir;
 542         const char *real_git_dir = NULL;
 543         const char *work_tree;
 544         const char *template_dir = NULL;
 545         unsigned int flags = 0;
 546         const char *object_format = NULL;
 547         const char *initial_branch = NULL;
 548         int hash_algo = GIT_HASH_UNKNOWN;
 549         const struct option init_db_options[] = {
 550                 OPT_STRING(0, "template", &template_dir, N_("template-directory"),
 551                                 N_("directory from which templates will be used")),
 552                 OPT_SET_INT(0, "bare", &is_bare_repository_cfg,
 553                                 N_("create a bare repository"), 1),
 554                 { OPTION_CALLBACK, 0, "shared", &init_shared_repository,
 555                         N_("permissions"),
 556                         N_("specify that the git repository is to be shared amongst several users"),
 557                         PARSE_OPT_OPTARG | PARSE_OPT_NONEG, shared_callback, 0},
 558                 OPT_BIT('q', "quiet", &flags, N_("be quiet"), INIT_DB_QUIET),
 559                 OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
 560                            N_("separate git dir from working tree")),
 561                 OPT_STRING('b', "initial-branch", &initial_branch, N_("name"),
 562                            N_("override the name of the initial branch")),
 563                 OPT_STRING(0, "object-format", &object_format, N_("hash"),
 564                            N_("specify the hash algorithm to use")),
 565                 OPT_END()
 566         };
 567
 568         argc = parse_options(argc, argv, prefix, init_db_options, init_db_usage, 0);
 569
 570         if (real_git_dir && is_bare_repository_cfg == 1)
 571                 die(_("options '%s' and '%s' cannot be used together"), "--separate-git-dir", "--bare");
 572
 573         if (real_git_dir && !is_absolute_path(real_git_dir))
 574                 real_git_dir = real_pathdup(real_git_dir, 1);
 575
 576         if (template_dir && *template_dir && !is_absolute_path(template_dir)) {
 577                 template_dir = absolute_pathdup(template_dir);
 578                 UNLEAK(template_dir);
 579         }
 580
 581         if (argc == 1) {
 582                 int mkdir_tried = 0;
 583         retry:
 584                 if (chdir(argv[0]) < 0) {
 585                         if (!mkdir_tried) {
 586                                 int saved;
 587                                 /*
 588                                  * At this point we haven't read any configuration,
 589                                  * and we know shared_repository should always be 0;
 590                                  * but just in case we play safe.
 591                                  */
 592                                 saved = get_shared_repository();
 593                                 set_shared_repository(0);
 594                                 switch (safe_create_leading_directories_const(argv[0])) {
 595                                 case SCLD_OK:
 596                                 case SCLD_PERMS:
 597                                         break;
 598                                 case SCLD_EXISTS:
 599                                         errno = EEXIST;
 600                                         /* fallthru */
 601                                 default:
 602                                         die_errno(_("cannot mkdir %s"), argv[0]);
 603                                         break;
 604                                 }
 605                                 set_shared_repository(saved);
 606                                 if (mkdir(argv[0], 0777) < 0)
 607                                         die_errno(_("cannot mkdir %s"), argv[0]);
 608                                 mkdir_tried = 1;
 609                                 goto retry;
 610                         }
 611                         die_errno(_("cannot chdir to %s"), argv[0]);
 612                 }
 613         } else if (0 < argc) {
 614                 usage(init_db_usage[0]);
 615         }
 616         if (is_bare_repository_cfg == 1) {
 617                 char *cwd = xgetcwd();
 618                 setenv(GIT_DIR_ENVIRONMENT, cwd, argc > 0);
 619                 free(cwd);
 620         }
 621
 622         if (object_format) {
 623                 hash_algo = hash_algo_by_name(object_format);
 624                 if (hash_algo == GIT_HASH_UNKNOWN)
 625                         die(_("unknown hash algorithm '%s'"), object_format);
 626         }
 627
 628         if (init_shared_repository != -1)
 629                 set_shared_repository(init_shared_repository);
 630
 631         /*
 632          * GIT_WORK_TREE makes sense only in conjunction with GIT_DIR
 633          * without --bare.  Catch the error early.
 634          */
 635         git_dir = xstrdup_or_null(getenv(GIT_DIR_ENVIRONMENT));
 636         work_tree = xstrdup_or_null(getenv(GIT_WORK_TREE_ENVIRONMENT));
 637         if ((!git_dir || is_bare_repository_cfg == 1) && work_tree)
 638                 die(_("%s (or --work-tree=<directory>) not allowed without "
 639                           "specifying %s (or --git-dir=<directory>)"),
 640                     GIT_WORK_TREE_ENVIRONMENT,
 641                     GIT_DIR_ENVIRONMENT);
 642
 643         /*
 644          * Set up the default .git directory contents
 645          */
 646         if (!git_dir)
 647                 git_dir = DEFAULT_GIT_DIR_ENVIRONMENT;
 648
 649         /*
 650          * When --separate-git-dir is used inside a linked worktree, take
 651          * care to ensure that the common .git/ directory is relocated, not
 652          * the worktree-specific .git/worktrees/<id>/ directory.
 653          */
 654         if (real_git_dir) {
 655                 int err;
 656                 const char *p;
 657                 struct strbuf sb = STRBUF_INIT;
 658
 659                 p = read_gitfile_gently(git_dir, &err);
 660                 if (p && get_common_dir(&sb, p)) {
 661                         struct strbuf mainwt = STRBUF_INIT;
 662
 663                         strbuf_addbuf(&mainwt, &sb);
 664                         strbuf_strip_suffix(&mainwt, "/.git");
 665                         if (chdir(mainwt.buf) < 0)
 666                                 die_errno(_("cannot chdir to %s"), mainwt.buf);
 667                         strbuf_release(&mainwt);
 668                         git_dir = strbuf_detach(&sb, NULL);
 669                 }
 670                 strbuf_release(&sb);
 671         }
 672
 673         if (is_bare_repository_cfg < 0)
 674                 is_bare_repository_cfg = guess_repository_type(git_dir);
 675
 676         if (!is_bare_repository_cfg) {
 677                 const char *git_dir_parent = strrchr(git_dir, '/');
 678                 if (git_dir_parent) {
 679                         char *rel = xstrndup(git_dir, git_dir_parent - git_dir);
 680                         git_work_tree_cfg = real_pathdup(rel, 1);
 681                         free(rel);
 682                 }
 683                 if (!git_work_tree_cfg)
 684                         git_work_tree_cfg = xgetcwd();
 685                 if (work_tree)
 686                         set_git_work_tree(work_tree);
 687                 else
 688                         set_git_work_tree(git_work_tree_cfg);
 689                 if (access(get_git_work_tree(), X_OK))
 690                         die_errno (_("Cannot access work tree '%s'"),
 691                                    get_git_work_tree());
 692         }
 693         else {
 694                 if (real_git_dir)
 695                         die(_("--separate-git-dir incompatible with bare repository"));
 696                 if (work_tree)
 697                         set_git_work_tree(work_tree);
 698         }
 699
 700         UNLEAK(real_git_dir);
 701         UNLEAK(git_dir);
 702         UNLEAK(work_tree);
 703
 704         flags |= INIT_DB_EXIST_OK;
 705         return init_db(git_dir, real_git_dir, template_dir, hash_algo,
 706                        initial_branch, flags);
 707 }