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         char *ref_git;
 213         struct strbuf alternate = STRBUF_INIT;
 214         struct remote *remote;
 215         struct transport *transport;
 216         const struct ref *extra;
 217
 218         /* Beware: real_path() and mkpath() return static buffer */
 219         ref_git = xstrdup(real_path(item->string));
 220         if (is_directory(mkpath("%s/.git/objects", ref_git))) {
 221                 char *ref_git_git = xstrdup(mkpath("%s/.git", ref_git));
 222                 free(ref_git);
 223                 ref_git = ref_git_git;
 224         } else if (!is_directory(mkpath("%s/objects", ref_git)))
 225                 die(_("reference repository '%s' is not a local directory."),
 226                     item->string);
 227
 228         strbuf_addf(&alternate, "%s/objects", ref_git);
 229         add_to_alternates_file(alternate.buf);
 230         strbuf_release(&alternate);
 231
 232         remote = remote_get(ref_git);
 233         transport = transport_get(remote, ref_git);
 234         for (extra = transport_get_remote_refs(transport); extra;
 235              extra = extra->next)
 236                 add_extra_ref(extra->name, extra->old_sha1, 0);
 237
 238         transport_disconnect(transport);
 239         free(ref_git);
 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_alternates(struct strbuf *src, struct strbuf *dst,
 249                             const char *src_repo)
 250 {
 251         /*
 252          * Read from the source objects/info/alternates file
 253          * and copy the entries to corresponding file in the
 254          * destination repository with add_to_alternates_file().
 255          * Both src and dst have "$path/objects/info/alternates".
 256          *
 257          * Instead of copying bit-for-bit from the original,
 258          * we need to append to existing one so that the already
 259          * created entry via "clone -s" is not lost, and also
 260          * to turn entries with paths relative to the original
 261          * absolute, so that they can be used in the new repository.
 262          */
 263         FILE *in = fopen(src->buf, "r");
 264         struct strbuf line = STRBUF_INIT;
 265
 266         while (strbuf_getline(&line, in, '\n') != EOF) {
 267                 char *abs_path, abs_buf[PATH_MAX];
 268                 if (!line.len || line.buf[0] == '#')
 269                         continue;
 270                 if (is_absolute_path(line.buf)) {
 271                         add_to_alternates_file(line.buf);
 272                         continue;
 273                 }
 274                 abs_path = mkpath("%s/objects/%s", src_repo, line.buf);
 275                 normalize_path_copy(abs_buf, abs_path);
 276                 add_to_alternates_file(abs_buf);
 277         }
 278         strbuf_release(&line);
 279         fclose(in);
 280 }
 281
 282 static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
 283                                    const char *src_repo, int src_baselen)
 284 {
 285         struct dirent *de;
 286         struct stat buf;
 287         int src_len, dest_len;
 288         DIR *dir;
 289
 290         dir = opendir(src->buf);
 291         if (!dir)
 292                 die_errno(_("failed to open '%s'"), src->buf);
 293
 294         if (mkdir(dest->buf, 0777)) {
 295                 if (errno != EEXIST)
 296                         die_errno(_("failed to create directory '%s'"), dest->buf);
 297                 else if (stat(dest->buf, &buf))
 298                         die_errno(_("failed to stat '%s'"), dest->buf);
 299                 else if (!S_ISDIR(buf.st_mode))
 300                         die(_("%s exists and is not a directory"), dest->buf);
 301         }
 302
 303         strbuf_addch(src, '/');
 304         src_len = src->len;
 305         strbuf_addch(dest, '/');
 306         dest_len = dest->len;
 307
 308         while ((de = readdir(dir)) != NULL) {
 309                 strbuf_setlen(src, src_len);
 310                 strbuf_addstr(src, de->d_name);
 311                 strbuf_setlen(dest, dest_len);
 312                 strbuf_addstr(dest, de->d_name);
 313                 if (stat(src->buf, &buf)) {
 314                         warning (_("failed to stat %s\n"), src->buf);
 315                         continue;
 316                 }
 317                 if (S_ISDIR(buf.st_mode)) {
 318                         if (de->d_name[0] != '.')
 319                                 copy_or_link_directory(src, dest,
 320                                                        src_repo, src_baselen);
 321                         continue;
 322                 }
 323
 324                 /* Files that cannot be copied bit-for-bit... */
 325                 if (!strcmp(src->buf + src_baselen, "/info/alternates")) {
 326                         copy_alternates(src, dest, src_repo);
 327                         continue;
 328                 }
 329
 330                 if (unlink(dest->buf) && errno != ENOENT)
 331                         die_errno(_("failed to unlink '%s'"), dest->buf);
 332                 if (!option_no_hardlinks) {
 333                         if (!link(src->buf, dest->buf))
 334                                 continue;
 335                         if (option_local)
 336                                 die_errno(_("failed to create link '%s'"), dest->buf);
 337                         option_no_hardlinks = 1;
 338                 }
 339                 if (copy_file_with_time(dest->buf, src->buf, 0666))
 340                         die_errno(_("failed to copy file to '%s'"), dest->buf);
 341         }
 342         closedir(dir);
 343 }
 344
 345 static const struct ref *clone_local(const char *src_repo,
 346                                      const char *dest_repo)
 347 {
 348         const struct ref *ret;
 349         struct remote *remote;
 350         struct transport *transport;
 351
 352         if (option_shared) {
 353                 struct strbuf alt = STRBUF_INIT;
 354                 strbuf_addf(&alt, "%s/objects", src_repo);
 355                 add_to_alternates_file(alt.buf);
 356                 strbuf_release(&alt);
 357         } else {
 358                 struct strbuf src = STRBUF_INIT;
 359                 struct strbuf dest = STRBUF_INIT;
 360                 strbuf_addf(&src, "%s/objects", src_repo);
 361                 strbuf_addf(&dest, "%s/objects", dest_repo);
 362                 copy_or_link_directory(&src, &dest, src_repo, src.len);
 363                 strbuf_release(&src);
 364                 strbuf_release(&dest);
 365         }
 366
 367         remote = remote_get(src_repo);
 368         transport = transport_get(remote, src_repo);
 369         ret = transport_get_remote_refs(transport);
 370         transport_disconnect(transport);
 371         if (0 <= option_verbosity)
 372                 printf(_("done.\n"));
 373         return ret;
 374 }
 375
 376 static const char *junk_work_tree;
 377 static const char *junk_git_dir;
 378 static pid_t junk_pid;
 379
 380 static void remove_junk(void)
 381 {
 382         struct strbuf sb = STRBUF_INIT;
 383         if (getpid() != junk_pid)
 384                 return;
 385         if (junk_git_dir) {
 386                 strbuf_addstr(&sb, junk_git_dir);
 387                 remove_dir_recursively(&sb, 0);
 388                 strbuf_reset(&sb);
 389         }
 390         if (junk_work_tree) {
 391                 strbuf_addstr(&sb, junk_work_tree);
 392                 remove_dir_recursively(&sb, 0);
 393                 strbuf_reset(&sb);
 394         }
 395 }
 396
 397 static void remove_junk_on_signal(int signo)
 398 {
 399         remove_junk();
 400         sigchain_pop(signo);
 401         raise(signo);
 402 }
 403
 404 static struct ref *wanted_peer_refs(const struct ref *refs,
 405                 struct refspec *refspec)
 406 {
 407         struct ref *local_refs = NULL;
 408         struct ref **tail = &local_refs;
 409
 410         get_fetch_map(refs, refspec, &tail, 0);
 411         if (!option_mirror)
 412                 get_fetch_map(refs, tag_refspec, &tail, 0);
 413
 414         return local_refs;
 415 }
 416
 417 static void write_remote_refs(const struct ref *local_refs)
 418 {
 419         const struct ref *r;
 420
 421         for (r = local_refs; r; r = r->next)
 422                 add_extra_ref(r->peer_ref->name, r->old_sha1, 0);
 423
 424         pack_refs(PACK_REFS_ALL);
 425         clear_extra_refs();
 426 }
 427
 428 int cmd_clone(int argc, const char **argv, const char *prefix)
 429 {
 430         int is_bundle = 0, is_local;
 431         struct stat buf;
 432         const char *repo_name, *repo, *work_tree, *git_dir;
 433         char *path, *dir;
 434         int dest_exists;
 435         const struct ref *refs, *remote_head;
 436         const struct ref *remote_head_points_at;
 437         const struct ref *our_head_points_at;
 438         struct ref *mapped_refs;
 439         struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
 440         struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
 441         struct transport *transport = NULL;
 442         char *src_ref_prefix = "refs/heads/";
 443         int err = 0;
 444
 445         struct refspec *refspec;
 446         const char *fetch_pattern;
 447
 448         junk_pid = getpid();
 449
 450         packet_trace_identity("clone");
 451         argc = parse_options(argc, argv, prefix, builtin_clone_options,
 452                              builtin_clone_usage, 0);
 453
 454         if (argc > 2)
 455                 usage_msg_opt(_("Too many arguments."),
 456                         builtin_clone_usage, builtin_clone_options);
 457
 458         if (argc == 0)
 459                 usage_msg_opt(_("You must specify a repository to clone."),
 460                         builtin_clone_usage, builtin_clone_options);
 461
 462         if (option_mirror)
 463                 option_bare = 1;
 464
 465         if (option_bare) {
 466                 if (option_origin)
 467                         die(_("--bare and --origin %s options are incompatible."),
 468                             option_origin);
 469                 option_no_checkout = 1;
 470         }
 471
 472         if (!option_origin)
 473                 option_origin = "origin";
 474
 475         repo_name = argv[0];
 476
 477         path = get_repo_path(repo_name, &is_bundle);
 478         if (path)
 479                 repo = xstrdup(absolute_path(repo_name));
 480         else if (!strchr(repo_name, ':'))
 481                 die(_("repository '%s' does not exist"), repo_name);
 482         else
 483                 repo = repo_name;
 484         is_local = path && !is_bundle;
 485         if (is_local && option_depth)
 486                 warning(_("--depth is ignored in local clones; use file:// instead."));
 487
 488         if (argc == 2)
 489                 dir = xstrdup(argv[1]);
 490         else
 491                 dir = guess_dir_name(repo_name, is_bundle, option_bare);
 492         strip_trailing_slashes(dir);
 493
 494         dest_exists = !stat(dir, &buf);
 495         if (dest_exists && !is_empty_dir(dir))
 496                 die(_("destination path '%s' already exists and is not "
 497                         "an empty directory."), dir);
 498
 499         strbuf_addf(&reflog_msg, "clone: from %s", repo);
 500
 501         if (option_bare)
 502                 work_tree = NULL;
 503         else {
 504                 work_tree = getenv("GIT_WORK_TREE");
 505                 if (work_tree && !stat(work_tree, &buf))
 506                         die(_("working tree '%s' already exists."), work_tree);
 507         }
 508
 509         if (option_bare || work_tree)
 510                 git_dir = xstrdup(dir);
 511         else {
 512                 work_tree = dir;
 513                 git_dir = xstrdup(mkpath("%s/.git", dir));
 514         }
 515
 516         if (!option_bare) {
 517                 junk_work_tree = work_tree;
 518                 if (safe_create_leading_directories_const(work_tree) < 0)
 519                         die_errno(_("could not create leading directories of '%s'"),
 520                                   work_tree);
 521                 if (!dest_exists && mkdir(work_tree, 0755))
 522                         die_errno(_("could not create work tree dir '%s'."),
 523                                   work_tree);
 524                 set_git_work_tree(work_tree);
 525         }
 526         junk_git_dir = git_dir;
 527         atexit(remove_junk);
 528         sigchain_push_common(remove_junk_on_signal);
 529
 530         setenv(CONFIG_ENVIRONMENT, mkpath("%s/config", git_dir), 1);
 531
 532         if (safe_create_leading_directories_const(git_dir) < 0)
 533                 die(_("could not create leading directories of '%s'"), git_dir);
 534
 535         set_git_dir_init(git_dir, real_git_dir, 0);
 536         if (real_git_dir)
 537                 git_dir = real_git_dir;
 538
 539         if (0 <= option_verbosity) {
 540                 if (option_bare)
 541                         printf(_("Cloning into bare repository %s...\n"), dir);
 542                 else
 543                         printf(_("Cloning into %s...\n"), dir);
 544         }
 545         init_db(option_template, INIT_DB_QUIET);
 546
 547         /*
 548          * At this point, the config exists, so we do not need the
 549          * environment variable.  We actually need to unset it, too, to
 550          * re-enable parsing of the global configs.
 551          */
 552         unsetenv(CONFIG_ENVIRONMENT);
 553
 554         git_config(git_default_config, NULL);
 555
 556         if (option_bare) {
 557                 if (option_mirror)
 558                         src_ref_prefix = "refs/";
 559                 strbuf_addstr(&branch_top, src_ref_prefix);
 560
 561                 git_config_set("core.bare", "true");
 562         } else {
 563                 strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
 564         }
 565
 566         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
 567
 568         if (option_mirror || !option_bare) {
 569                 /* Configure the remote */
 570                 strbuf_addf(&key, "remote.%s.fetch", option_origin);
 571                 git_config_set_multivar(key.buf, value.buf, "^$", 0);
 572                 strbuf_reset(&key);
 573
 574                 if (option_mirror) {
 575                         strbuf_addf(&key, "remote.%s.mirror", option_origin);
 576                         git_config_set(key.buf, "true");
 577                         strbuf_reset(&key);
 578                 }
 579         }
 580
 581         strbuf_addf(&key, "remote.%s.url", option_origin);
 582         git_config_set(key.buf, repo);
 583         strbuf_reset(&key);
 584
 585         if (option_reference.nr)
 586                 setup_reference();
 587
 588         fetch_pattern = value.buf;
 589         refspec = parse_fetch_refspec(1, &fetch_pattern);
 590
 591         strbuf_reset(&value);
 592
 593         if (is_local) {
 594                 refs = clone_local(path, git_dir);
 595                 mapped_refs = wanted_peer_refs(refs, refspec);
 596         } else {
 597                 struct remote *remote = remote_get(option_origin);
 598                 transport = transport_get(remote, remote->url[0]);
 599
 600                 if (!transport->get_refs_list || !transport->fetch)
 601                         die(_("Don't know how to clone %s"), transport->url);
 602
 603                 transport_set_option(transport, TRANS_OPT_KEEP, "yes");
 604
 605                 if (option_depth)
 606                         transport_set_option(transport, TRANS_OPT_DEPTH,
 607                                              option_depth);
 608
 609                 transport_set_verbosity(transport, option_verbosity, option_progress);
 610
 611                 if (option_upload_pack)
 612                         transport_set_option(transport, TRANS_OPT_UPLOADPACK,
 613                                              option_upload_pack);
 614
 615                 refs = transport_get_remote_refs(transport);
 616                 if (refs) {
 617                         mapped_refs = wanted_peer_refs(refs, refspec);
 618                         transport_fetch_refs(transport, mapped_refs);
 619                 }
 620         }
 621
 622         if (refs) {
 623                 clear_extra_refs();
 624
 625                 write_remote_refs(mapped_refs);
 626
 627                 remote_head = find_ref_by_name(refs, "HEAD");
 628                 remote_head_points_at =
 629                         guess_remote_head(remote_head, mapped_refs, 0);
 630
 631                 if (option_branch) {
 632                         struct strbuf head = STRBUF_INIT;
 633                         strbuf_addstr(&head, src_ref_prefix);
 634                         strbuf_addstr(&head, option_branch);
 635                         our_head_points_at =
 636                                 find_ref_by_name(mapped_refs, head.buf);
 637                         strbuf_release(&head);
 638
 639                         if (!our_head_points_at) {
 640                                 warning(_("Remote branch %s not found in "
 641                                         "upstream %s, using HEAD instead"),
 642                                         option_branch, option_origin);
 643                                 our_head_points_at = remote_head_points_at;
 644                         }
 645                 }
 646                 else
 647                         our_head_points_at = remote_head_points_at;
 648         }
 649         else {
 650                 warning(_("You appear to have cloned an empty repository."));
 651                 our_head_points_at = NULL;
 652                 remote_head_points_at = NULL;
 653                 remote_head = NULL;
 654                 option_no_checkout = 1;
 655                 if (!option_bare)
 656                         install_branch_config(0, "master", option_origin,
 657                                               "refs/heads/master");
 658         }
 659
 660         if (remote_head_points_at && !option_bare) {
 661                 struct strbuf head_ref = STRBUF_INIT;
 662                 strbuf_addstr(&head_ref, branch_top.buf);
 663                 strbuf_addstr(&head_ref, "HEAD");
 664                 create_symref(head_ref.buf,
 665                               remote_head_points_at->peer_ref->name,
 666                               reflog_msg.buf);
 667         }
 668
 669         if (our_head_points_at) {
 670                 /* Local default branch link */
 671                 create_symref("HEAD", our_head_points_at->name, NULL);
 672                 if (!option_bare) {
 673                         const char *head = skip_prefix(our_head_points_at->name,
 674                                                        "refs/heads/");
 675                         update_ref(reflog_msg.buf, "HEAD",
 676                                    our_head_points_at->old_sha1,
 677                                    NULL, 0, DIE_ON_ERR);
 678                         install_branch_config(0, head, option_origin,
 679                                               our_head_points_at->name);
 680                 }
 681         } else if (remote_head) {
 682                 /* Source had detached HEAD pointing somewhere. */
 683                 if (!option_bare) {
 684                         update_ref(reflog_msg.buf, "HEAD",
 685                                    remote_head->old_sha1,
 686                                    NULL, REF_NODEREF, DIE_ON_ERR);
 687                         our_head_points_at = remote_head;
 688                 }
 689         } else {
 690                 /* Nothing to checkout out */
 691                 if (!option_no_checkout)
 692                         warning(_("remote HEAD refers to nonexistent ref, "
 693                                 "unable to checkout.\n"));
 694                 option_no_checkout = 1;
 695         }
 696
 697         if (transport) {
 698                 transport_unlock_pack(transport);
 699                 transport_disconnect(transport);
 700         }
 701
 702         if (!option_no_checkout) {
 703                 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
 704                 struct unpack_trees_options opts;
 705                 struct tree *tree;
 706                 struct tree_desc t;
 707                 int fd;
 708
 709                 /* We need to be in the new work tree for the checkout */
 710                 setup_work_tree();
 711
 712                 fd = hold_locked_index(lock_file, 1);
 713
 714                 memset(&opts, 0, sizeof opts);
 715                 opts.update = 1;
 716                 opts.merge = 1;
 717                 opts.fn = oneway_merge;
 718                 opts.verbose_update = (option_verbosity > 0);
 719                 opts.src_index = &the_index;
 720                 opts.dst_index = &the_index;
 721
 722                 tree = parse_tree_indirect(our_head_points_at->old_sha1);
 723                 parse_tree(tree);
 724                 init_tree_desc(&t, tree->buffer, tree->size);
 725                 unpack_trees(1, &t, &opts);
 726
 727                 if (write_cache(fd, active_cache, active_nr) ||
 728                     commit_locked_index(lock_file))
 729                         die(_("unable to write new index file"));
 730
 731                 err |= run_hook(NULL, "post-checkout", sha1_to_hex(null_sha1),
 732                                 sha1_to_hex(our_head_points_at->old_sha1), "1",
 733                                 NULL);
 734
 735                 if (!err && option_recursive)
 736                         err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
 737         }
 738
 739         strbuf_release(&reflog_msg);
 740         strbuf_release(&branch_top);
 741         strbuf_release(&key);
 742         strbuf_release(&value);
 743         junk_pid = 0;
 744         return err;
 745 }