git.oblomov.eu Git - git/blob - builtin/clone.c

   1 /*
   2  * Builtin "git clone"
   3  *
   4  * Copyright (c) 2007 Kristian Høgsberg <krh@redhat.com>,
   5  *               2008 Daniel Barkalow <barkalow@iabervon.org>
   6  * Based on git-commit.sh by Junio C Hamano and Linus Torvalds
   7  *
   8  * Clone a repository into a different directory that does not yet exist.
   9  */
  10
  11 #include "builtin.h"
  12 #include "parse-options.h"
  13 #include "fetch-pack.h"
  14 #include "refs.h"
  15 #include "tree.h"
  16 #include "tree-walk.h"
  17 #include "unpack-trees.h"
  18 #include "transport.h"
  19 #include "strbuf.h"
  20 #include "dir.h"
  21 #include "pack-refs.h"
  22 #include "sigchain.h"
  23 #include "branch.h"
  24 #include "remote.h"
  25 #include "run-command.h"
  26
  27 /*
  28  * Overall FIXMEs:
  29  *  - respect DB_ENVIRONMENT for .git/objects.
  30  *
  31  * Implementation notes:
  32  *  - dropping use-separate-remote and no-separate-remote compatibility
  33  *
  34  */
  35 static const char * const builtin_clone_usage[] = {
  36         "git clone [options] [--] <repo> [<dir>]",
  37         NULL
  38 };
  39
  40 static int option_no_checkout, option_bare, option_mirror;
  41 static int option_local, option_no_hardlinks, option_shared, option_recursive;
  42 static char *option_template, *option_depth;
  43 static char *option_origin = NULL;
  44 static char *option_branch = NULL;
  45 static const char *real_git_dir;
  46 static char *option_upload_pack = "git-upload-pack";
  47 static int option_verbosity;
  48 static int option_progress;
  49 static struct string_list option_reference;
  50
  51 static int opt_parse_reference(const struct option *opt, const char *arg, int unset)
  52 {
  53         struct string_list *option_reference = opt->value;
  54         if (!arg)
  55                 return -1;
  56         string_list_append(option_reference, arg);
  57         return 0;
  58 }
  59
  60 static struct option builtin_clone_options[] = {
  61         OPT__VERBOSITY(&option_verbosity),
  62         OPT_BOOLEAN(0, "progress", &option_progress,
  63                         "force progress reporting"),
  64         OPT_BOOLEAN('n', "no-checkout", &option_no_checkout,
  65                     "don't create a checkout"),
  66         OPT_BOOLEAN(0, "bare", &option_bare, "create a bare repository"),
  67         { OPTION_BOOLEAN, 0, "naked", &option_bare, NULL,
  68                 "create a bare repository",
  69                 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
  70         OPT_BOOLEAN(0, "mirror", &option_mirror,
  71                     "create a mirror repository (implies bare)"),
  72         OPT_BOOLEAN('l', "local", &option_local,
  73                     "to clone from a local repository"),
  74         OPT_BOOLEAN(0, "no-hardlinks", &option_no_hardlinks,
  75                     "don't use local hardlinks, always copy"),
  76         OPT_BOOLEAN('s', "shared", &option_shared,
  77                     "setup as shared repository"),
  78         OPT_BOOLEAN(0, "recursive", &option_recursive,
  79                     "initialize submodules in the clone"),
  80         OPT_BOOLEAN(0, "recurse-submodules", &option_recursive,
  81                     "initialize submodules in the clone"),
  82         OPT_STRING(0, "template", &option_template, "template-directory",
  83                    "directory from which templates will be used"),
  84         OPT_CALLBACK(0 , "reference", &option_reference, "repo",
  85                      "reference repository", &opt_parse_reference),
  86         OPT_STRING('o', "origin", &option_origin, "branch",
  87                    "use <branch> instead of 'origin' to track upstream"),
  88         OPT_STRING('b', "branch", &option_branch, "branch",
  89                    "checkout <branch> instead of the remote's HEAD"),
  90         OPT_STRING('u', "upload-pack", &option_upload_pack, "path",
  91                    "path to git-upload-pack on the remote"),
  92         OPT_STRING(0, "depth", &option_depth, "depth",
  93                     "create a shallow clone of that depth"),
  94         OPT_STRING(0, "separate-git-dir", &real_git_dir, "gitdir",
  95                    "separate git dir from working tree"),
  96
  97         OPT_END()
  98 };
  99
 100 static const char *argv_submodule[] = {
 101         "submodule", "update", "--init", "--recursive", NULL
 102 };
 103
 104 static char *get_repo_path(const char *repo, int *is_bundle)
 105 {
 106         static char *suffix[] = { "/.git", ".git", "" };
 107         static char *bundle_suffix[] = { ".bundle", "" };
 108         struct stat st;
 109         int i;
 110
 111         for (i = 0; i < ARRAY_SIZE(suffix); i++) {
 112                 const char *path;
 113                 path = mkpath("%s%s", repo, suffix[i]);
 114                 if (is_directory(path)) {
 115                         *is_bundle = 0;
 116                         return xstrdup(absolute_path(path));
 117                 }
 118         }
 119
 120         for (i = 0; i < ARRAY_SIZE(bundle_suffix); i++) {
 121                 const char *path;
 122                 path = mkpath("%s%s", repo, bundle_suffix[i]);
 123                 if (!stat(path, &st) && S_ISREG(st.st_mode)) {
 124                         *is_bundle = 1;
 125                         return xstrdup(absolute_path(path));
 126                 }
 127         }
 128
 129         return NULL;
 130 }
 131
 132 static char *guess_dir_name(const char *repo, int is_bundle, int is_bare)
 133 {
 134         const char *end = repo + strlen(repo), *start;
 135         char *dir;
 136
 137         /*
 138          * Strip trailing spaces, slashes and /.git
 139          */
 140         while (repo < end && (is_dir_sep(end[-1]) || isspace(end[-1])))
 141                 end--;
 142         if (end - repo > 5 && is_dir_sep(end[-5]) &&
 143             !strncmp(end - 4, ".git", 4)) {
 144                 end -= 5;
 145                 while (repo < end && is_dir_sep(end[-1]))
 146                         end--;
 147         }
 148
 149         /*
 150          * Find last component, but be prepared that repo could have
 151          * the form  "remote.example.com:foo.git", i.e. no slash
 152          * in the directory part.
 153          */
 154         start = end;
 155         while (repo < start && !is_dir_sep(start[-1]) && start[-1] != ':')
 156                 start--;
 157
 158         /*
 159          * Strip .{bundle,git}.
 160          */
 161         if (is_bundle) {
 162                 if (end - start > 7 && !strncmp(end - 7, ".bundle", 7))
 163                         end -= 7;
 164         } else {
 165                 if (end - start > 4 && !strncmp(end - 4, ".git", 4))
 166                         end -= 4;
 167         }
 168
 169         if (is_bare) {
 170                 struct strbuf result = STRBUF_INIT;
 171                 strbuf_addf(&result, "%.*s.git", (int)(end - start), start);
 172                 dir = strbuf_detach(&result, NULL);
 173         } else
 174                 dir = xstrndup(start, end - start);
 175         /*
 176          * Replace sequences of 'control' characters and whitespace
 177          * with one ascii space, remove leading and trailing spaces.
 178          */
 179         if (*dir) {
 180                 char *out = dir;
 181                 int prev_space = 1 /* strip leading whitespace */;
 182                 for (end = dir; *end; ++end) {
 183                         char ch = *end;
 184                         if ((unsigned char)ch < '\x20')
 185                                 ch = '\x20';
 186                         if (isspace(ch)) {
 187                                 if (prev_space)
 188                                         continue;
 189                                 prev_space = 1;
 190                         } else
 191                                 prev_space = 0;
 192                         *out++ = ch;
 193                 }
 194                 *out = '\0';
 195                 if (out > dir && prev_space)
 196                         out[-1] = '\0';
 197         }
 198         return dir;
 199 }
 200
 201 static void strip_trailing_slashes(char *dir)
 202 {
 203         char *end = dir + strlen(dir);
 204
 205         while (dir < end - 1 && is_dir_sep(end[-1]))
 206                 end--;
 207         *end = '\0';
 208 }
 209
 210 static int add_one_reference(struct string_list_item *item, void *cb_data)
 211 {
 212         const char *ref_git;
 213         char *ref_git_copy;
 214
 215         struct remote *remote;
 216         struct transport *transport;
 217         const struct ref *extra;
 218
 219         ref_git = real_path(item->string);
 220
 221         if (is_directory(mkpath("%s/.git/objects", ref_git)))
 222                 ref_git = mkpath("%s/.git", ref_git);
 223         else if (!is_directory(mkpath("%s/objects", ref_git)))
 224                 die(_("reference repository '%s' is not a local directory."),
 225                     item->string);
 226
 227         ref_git_copy = xstrdup(ref_git);
 228
 229         add_to_alternates_file(ref_git_copy);
 230
 231         remote = remote_get(ref_git_copy);
 232         transport = transport_get(remote, ref_git_copy);
 233         for (extra = transport_get_remote_refs(transport); extra;
 234              extra = extra->next)
 235                 add_extra_ref(extra->name, extra->old_sha1, 0);
 236
 237         transport_disconnect(transport);
 238
 239         free(ref_git_copy);
 240         return 0;
 241 }
 242
 243 static void setup_reference(void)
 244 {
 245         for_each_string_list(&option_reference, add_one_reference, NULL);
 246 }
 247
 248 static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest)
 249 {
 250         struct dirent *de;
 251         struct stat buf;
 252         int src_len, dest_len;
 253         DIR *dir;
 254
 255         dir = opendir(src->buf);
 256         if (!dir)
 257                 die_errno(_("failed to open '%s'"), src->buf);
 258
 259         if (mkdir(dest->buf, 0777)) {
 260                 if (errno != EEXIST)
 261                         die_errno(_("failed to create directory '%s'"), dest->buf);
 262                 else if (stat(dest->buf, &buf))
 263                         die_errno(_("failed to stat '%s'"), dest->buf);
 264                 else if (!S_ISDIR(buf.st_mode))
 265                         die(_("%s exists and is not a directory"), dest->buf);
 266         }
 267
 268         strbuf_addch(src, '/');
 269         src_len = src->len;
 270         strbuf_addch(dest, '/');
 271         dest_len = dest->len;
 272
 273         while ((de = readdir(dir)) != NULL) {
 274                 strbuf_setlen(src, src_len);
 275                 strbuf_addstr(src, de->d_name);
 276                 strbuf_setlen(dest, dest_len);
 277                 strbuf_addstr(dest, de->d_name);
 278                 if (stat(src->buf, &buf)) {
 279                         warning (_("failed to stat %s\n"), src->buf);
 280                         continue;
 281                 }
 282                 if (S_ISDIR(buf.st_mode)) {
 283                         if (de->d_name[0] != '.')
 284                                 copy_or_link_directory(src, dest);
 285                         continue;
 286                 }
 287
 288                 if (unlink(dest->buf) && errno != ENOENT)
 289                         die_errno(_("failed to unlink '%s'"), dest->buf);
 290                 if (!option_no_hardlinks) {
 291                         if (!link(src->buf, dest->buf))
 292                                 continue;
 293                         if (option_local)
 294                                 die_errno(_("failed to create link '%s'"), dest->buf);
 295                         option_no_hardlinks = 1;
 296                 }
 297                 if (copy_file_with_time(dest->buf, src->buf, 0666))
 298                         die_errno(_("failed to copy file to '%s'"), dest->buf);
 299         }
 300         closedir(dir);
 301 }
 302
 303 static const struct ref *clone_local(const char *src_repo,
 304                                      const char *dest_repo)
 305 {
 306         const struct ref *ret;
 307         struct strbuf src = STRBUF_INIT;
 308         struct strbuf dest = STRBUF_INIT;
 309         struct remote *remote;
 310         struct transport *transport;
 311
 312         if (option_shared)
 313                 add_to_alternates_file(src_repo);
 314         else {
 315                 strbuf_addf(&src, "%s/objects", src_repo);
 316                 strbuf_addf(&dest, "%s/objects", dest_repo);
 317                 copy_or_link_directory(&src, &dest);
 318                 strbuf_release(&src);
 319                 strbuf_release(&dest);
 320         }
 321
 322         remote = remote_get(src_repo);
 323         transport = transport_get(remote, src_repo);
 324         ret = transport_get_remote_refs(transport);
 325         transport_disconnect(transport);
 326         if (0 <= option_verbosity)
 327                 printf(_("done.\n"));
 328         return ret;
 329 }
 330
 331 static const char *junk_work_tree;
 332 static const char *junk_git_dir;
 333 static pid_t junk_pid;
 334
 335 static void remove_junk(void)
 336 {
 337         struct strbuf sb = STRBUF_INIT;
 338         if (getpid() != junk_pid)
 339                 return;
 340         if (junk_git_dir) {
 341                 strbuf_addstr(&sb, junk_git_dir);
 342                 remove_dir_recursively(&sb, 0);
 343                 strbuf_reset(&sb);
 344         }
 345         if (junk_work_tree) {
 346                 strbuf_addstr(&sb, junk_work_tree);
 347                 remove_dir_recursively(&sb, 0);
 348                 strbuf_reset(&sb);
 349         }
 350 }
 351
 352 static void remove_junk_on_signal(int signo)
 353 {
 354         remove_junk();
 355         sigchain_pop(signo);
 356         raise(signo);
 357 }
 358
 359 static struct ref *wanted_peer_refs(const struct ref *refs,
 360                 struct refspec *refspec)
 361 {
 362         struct ref *local_refs = NULL;
 363         struct ref **tail = &local_refs;
 364
 365         get_fetch_map(refs, refspec, &tail, 0);
 366         if (!option_mirror)
 367                 get_fetch_map(refs, tag_refspec, &tail, 0);
 368
 369         return local_refs;
 370 }
 371
 372 static void write_remote_refs(const struct ref *local_refs)
 373 {
 374         const struct ref *r;
 375
 376         for (r = local_refs; r; r = r->next)
 377                 add_extra_ref(r->peer_ref->name, r->old_sha1, 0);
 378
 379         pack_refs(PACK_REFS_ALL);
 380         clear_extra_refs();
 381 }
 382
 383 int cmd_clone(int argc, const char **argv, const char *prefix)
 384 {
 385         int is_bundle = 0, is_local;
 386         struct stat buf;
 387         const char *repo_name, *repo, *work_tree, *git_dir;
 388         char *path, *dir;
 389         int dest_exists;
 390         const struct ref *refs, *remote_head;
 391         const struct ref *remote_head_points_at;
 392         const struct ref *our_head_points_at;
 393         struct ref *mapped_refs;
 394         struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
 395         struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
 396         struct transport *transport = NULL;
 397         char *src_ref_prefix = "refs/heads/";
 398         int err = 0;
 399
 400         struct refspec *refspec;
 401         const char *fetch_pattern;
 402
 403         junk_pid = getpid();
 404
 405         packet_trace_identity("clone");
 406         argc = parse_options(argc, argv, prefix, builtin_clone_options,
 407                              builtin_clone_usage, 0);
 408
 409         if (argc > 2)
 410                 usage_msg_opt(_("Too many arguments."),
 411                         builtin_clone_usage, builtin_clone_options);
 412
 413         if (argc == 0)
 414                 usage_msg_opt(_("You must specify a repository to clone."),
 415                         builtin_clone_usage, builtin_clone_options);
 416
 417         if (option_mirror)
 418                 option_bare = 1;
 419
 420         if (option_bare) {
 421                 if (option_origin)
 422                         die(_("--bare and --origin %s options are incompatible."),
 423                             option_origin);
 424                 option_no_checkout = 1;
 425         }
 426
 427         if (!option_origin)
 428                 option_origin = "origin";
 429
 430         repo_name = argv[0];
 431
 432         path = get_repo_path(repo_name, &is_bundle);
 433         if (path)
 434                 repo = xstrdup(absolute_path(repo_name));
 435         else if (!strchr(repo_name, ':'))
 436                 die(_("repository '%s' does not exist"), repo_name);
 437         else
 438                 repo = repo_name;
 439         is_local = path && !is_bundle;
 440         if (is_local && option_depth)
 441                 warning(_("--depth is ignored in local clones; use file:// instead."));
 442
 443         if (argc == 2)
 444                 dir = xstrdup(argv[1]);
 445         else
 446                 dir = guess_dir_name(repo_name, is_bundle, option_bare);
 447         strip_trailing_slashes(dir);
 448
 449         dest_exists = !stat(dir, &buf);
 450         if (dest_exists && !is_empty_dir(dir))
 451                 die(_("destination path '%s' already exists and is not "
 452                         "an empty directory."), dir);
 453
 454         strbuf_addf(&reflog_msg, "clone: from %s", repo);
 455
 456         if (option_bare)
 457                 work_tree = NULL;
 458         else {
 459                 work_tree = getenv("GIT_WORK_TREE");
 460                 if (work_tree && !stat(work_tree, &buf))
 461                         die(_("working tree '%s' already exists."), work_tree);
 462         }
 463
 464         if (option_bare || work_tree)
 465                 git_dir = xstrdup(dir);
 466         else {
 467                 work_tree = dir;
 468                 git_dir = xstrdup(mkpath("%s/.git", dir));
 469         }
 470
 471         if (!option_bare) {
 472                 junk_work_tree = work_tree;
 473                 if (safe_create_leading_directories_const(work_tree) < 0)
 474                         die_errno(_("could not create leading directories of '%s'"),
 475                                   work_tree);
 476                 if (!dest_exists && mkdir(work_tree, 0755))
 477                         die_errno(_("could not create work tree dir '%s'."),
 478                                   work_tree);
 479                 set_git_work_tree(work_tree);
 480         }
 481         junk_git_dir = git_dir;
 482         atexit(remove_junk);
 483         sigchain_push_common(remove_junk_on_signal);
 484
 485         setenv(CONFIG_ENVIRONMENT, mkpath("%s/config", git_dir), 1);
 486
 487         if (safe_create_leading_directories_const(git_dir) < 0)
 488                 die(_("could not create leading directories of '%s'"), git_dir);
 489
 490         set_git_dir_init(git_dir, real_git_dir, 0);
 491         if (real_git_dir)
 492                 git_dir = real_git_dir;
 493
 494         if (0 <= option_verbosity) {
 495                 if (option_bare)
 496                         printf(_("Cloning into bare repository %s...\n"), dir);
 497                 else
 498                         printf(_("Cloning into %s...\n"), dir);
 499         }
 500         init_db(option_template, INIT_DB_QUIET);
 501
 502         /*
 503          * At this point, the config exists, so we do not need the
 504          * environment variable.  We actually need to unset it, too, to
 505          * re-enable parsing of the global configs.
 506          */
 507         unsetenv(CONFIG_ENVIRONMENT);
 508
 509         git_config(git_default_config, NULL);
 510
 511         if (option_bare) {
 512                 if (option_mirror)
 513                         src_ref_prefix = "refs/";
 514                 strbuf_addstr(&branch_top, src_ref_prefix);
 515
 516                 git_config_set("core.bare", "true");
 517         } else {
 518                 strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
 519         }
 520
 521         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
 522
 523         if (option_mirror || !option_bare) {
 524                 /* Configure the remote */
 525                 strbuf_addf(&key, "remote.%s.fetch", option_origin);
 526                 git_config_set_multivar(key.buf, value.buf, "^$", 0);
 527                 strbuf_reset(&key);
 528
 529                 if (option_mirror) {
 530                         strbuf_addf(&key, "remote.%s.mirror", option_origin);
 531                         git_config_set(key.buf, "true");
 532                         strbuf_reset(&key);
 533                 }
 534         }
 535
 536         strbuf_addf(&key, "remote.%s.url", option_origin);
 537         git_config_set(key.buf, repo);
 538         strbuf_reset(&key);
 539
 540         if (option_reference.nr)
 541                 setup_reference();
 542
 543         fetch_pattern = value.buf;
 544         refspec = parse_fetch_refspec(1, &fetch_pattern);
 545
 546         strbuf_reset(&value);
 547
 548         if (is_local) {
 549                 refs = clone_local(path, git_dir);
 550                 mapped_refs = wanted_peer_refs(refs, refspec);
 551         } else {
 552                 struct remote *remote = remote_get(option_origin);
 553                 transport = transport_get(remote, remote->url[0]);
 554
 555                 if (!transport->get_refs_list || !transport->fetch)
 556                         die(_("Don't know how to clone %s"), transport->url);
 557
 558                 transport_set_option(transport, TRANS_OPT_KEEP, "yes");
 559
 560                 if (option_depth)
 561                         transport_set_option(transport, TRANS_OPT_DEPTH,
 562                                              option_depth);
 563
 564                 transport_set_verbosity(transport, option_verbosity, option_progress);
 565
 566                 if (option_upload_pack)
 567                         transport_set_option(transport, TRANS_OPT_UPLOADPACK,
 568                                              option_upload_pack);
 569
 570                 refs = transport_get_remote_refs(transport);
 571                 if (refs) {
 572                         mapped_refs = wanted_peer_refs(refs, refspec);
 573                         transport_fetch_refs(transport, mapped_refs);
 574                 }
 575         }
 576
 577         if (refs) {
 578                 clear_extra_refs();
 579
 580                 write_remote_refs(mapped_refs);
 581
 582                 remote_head = find_ref_by_name(refs, "HEAD");
 583                 remote_head_points_at =
 584                         guess_remote_head(remote_head, mapped_refs, 0);
 585
 586                 if (option_branch) {
 587                         struct strbuf head = STRBUF_INIT;
 588                         strbuf_addstr(&head, src_ref_prefix);
 589                         strbuf_addstr(&head, option_branch);
 590                         our_head_points_at =
 591                                 find_ref_by_name(mapped_refs, head.buf);
 592                         strbuf_release(&head);
 593
 594                         if (!our_head_points_at) {
 595                                 warning(_("Remote branch %s not found in "
 596                                         "upstream %s, using HEAD instead"),
 597                                         option_branch, option_origin);
 598                                 our_head_points_at = remote_head_points_at;
 599                         }
 600                 }
 601                 else
 602                         our_head_points_at = remote_head_points_at;
 603         }
 604         else {
 605                 warning(_("You appear to have cloned an empty repository."));
 606                 our_head_points_at = NULL;
 607                 remote_head_points_at = NULL;
 608                 remote_head = NULL;
 609                 option_no_checkout = 1;
 610                 if (!option_bare)
 611                         install_branch_config(0, "master", option_origin,
 612                                               "refs/heads/master");
 613         }
 614
 615         if (remote_head_points_at && !option_bare) {
 616                 struct strbuf head_ref = STRBUF_INIT;
 617                 strbuf_addstr(&head_ref, branch_top.buf);
 618                 strbuf_addstr(&head_ref, "HEAD");
 619                 create_symref(head_ref.buf,
 620                               remote_head_points_at->peer_ref->name,
 621                               reflog_msg.buf);
 622         }
 623
 624         if (our_head_points_at) {
 625                 /* Local default branch link */
 626                 create_symref("HEAD", our_head_points_at->name, NULL);
 627                 if (!option_bare) {
 628                         const char *head = skip_prefix(our_head_points_at->name,
 629                                                        "refs/heads/");
 630                         update_ref(reflog_msg.buf, "HEAD",
 631                                    our_head_points_at->old_sha1,
 632                                    NULL, 0, DIE_ON_ERR);
 633                         install_branch_config(0, head, option_origin,
 634                                               our_head_points_at->name);
 635                 }
 636         } else if (remote_head) {
 637                 /* Source had detached HEAD pointing somewhere. */
 638                 if (!option_bare) {
 639                         update_ref(reflog_msg.buf, "HEAD",
 640                                    remote_head->old_sha1,
 641                                    NULL, REF_NODEREF, DIE_ON_ERR);
 642                         our_head_points_at = remote_head;
 643                 }
 644         } else {
 645                 /* Nothing to checkout out */
 646                 if (!option_no_checkout)
 647                         warning(_("remote HEAD refers to nonexistent ref, "
 648                                 "unable to checkout.\n"));
 649                 option_no_checkout = 1;
 650         }
 651
 652         if (transport) {
 653                 transport_unlock_pack(transport);
 654                 transport_disconnect(transport);
 655         }
 656
 657         if (!option_no_checkout) {
 658                 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
 659                 struct unpack_trees_options opts;
 660                 struct tree *tree;
 661                 struct tree_desc t;
 662                 int fd;
 663
 664                 /* We need to be in the new work tree for the checkout */
 665                 setup_work_tree();
 666
 667                 fd = hold_locked_index(lock_file, 1);
 668
 669                 memset(&opts, 0, sizeof opts);
 670                 opts.update = 1;
 671                 opts.merge = 1;
 672                 opts.fn = oneway_merge;
 673                 opts.verbose_update = (option_verbosity > 0);
 674                 opts.src_index = &the_index;
 675                 opts.dst_index = &the_index;
 676
 677                 tree = parse_tree_indirect(our_head_points_at->old_sha1);
 678                 parse_tree(tree);
 679                 init_tree_desc(&t, tree->buffer, tree->size);
 680                 unpack_trees(1, &t, &opts);
 681
 682                 if (write_cache(fd, active_cache, active_nr) ||
 683                     commit_locked_index(lock_file))
 684                         die(_("unable to write new index file"));
 685
 686                 err |= run_hook(NULL, "post-checkout", sha1_to_hex(null_sha1),
 687                                 sha1_to_hex(our_head_points_at->old_sha1), "1",
 688                                 NULL);
 689
 690                 if (!err && option_recursive)
 691                         err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
 692         }
 693
 694         strbuf_release(&reflog_msg);
 695         strbuf_release(&branch_top);
 696         strbuf_release(&key);
 697         strbuf_release(&value);
 698         junk_pid = 0;
 699         return err;
 700 }