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 (stat(path, &st))
 115                         continue;
 116                 if (S_ISDIR(st.st_mode)) {
 117                         *is_bundle = 0;
 118                         return xstrdup(absolute_path(path));
 119                 } else if (S_ISREG(st.st_mode) && st.st_size > 8) {
 120                         /* Is it a "gitfile"? */
 121                         char signature[8];
 122                         int len, fd = open(path, O_RDONLY);
 123                         if (fd < 0)
 124                                 continue;
 125                         len = read_in_full(fd, signature, 8);
 126                         close(fd);
 127                         if (len != 8 || strncmp(signature, "gitdir: ", 8))
 128                                 continue;
 129                         path = read_gitfile(path);
 130                         if (path) {
 131                                 *is_bundle = 0;
 132                                 return xstrdup(absolute_path(path));
 133                         }
 134                 }
 135         }
 136
 137         for (i = 0; i < ARRAY_SIZE(bundle_suffix); i++) {
 138                 const char *path;
 139                 path = mkpath("%s%s", repo, bundle_suffix[i]);
 140                 if (!stat(path, &st) && S_ISREG(st.st_mode)) {
 141                         *is_bundle = 1;
 142                         return xstrdup(absolute_path(path));
 143                 }
 144         }
 145
 146         return NULL;
 147 }
 148
 149 static char *guess_dir_name(const char *repo, int is_bundle, int is_bare)
 150 {
 151         const char *end = repo + strlen(repo), *start;
 152         char *dir;
 153
 154         /*
 155          * Strip trailing spaces, slashes and /.git
 156          */
 157         while (repo < end && (is_dir_sep(end[-1]) || isspace(end[-1])))
 158                 end--;
 159         if (end - repo > 5 && is_dir_sep(end[-5]) &&
 160             !strncmp(end - 4, ".git", 4)) {
 161                 end -= 5;
 162                 while (repo < end && is_dir_sep(end[-1]))
 163                         end--;
 164         }
 165
 166         /*
 167          * Find last component, but be prepared that repo could have
 168          * the form  "remote.example.com:foo.git", i.e. no slash
 169          * in the directory part.
 170          */
 171         start = end;
 172         while (repo < start && !is_dir_sep(start[-1]) && start[-1] != ':')
 173                 start--;
 174
 175         /*
 176          * Strip .{bundle,git}.
 177          */
 178         if (is_bundle) {
 179                 if (end - start > 7 && !strncmp(end - 7, ".bundle", 7))
 180                         end -= 7;
 181         } else {
 182                 if (end - start > 4 && !strncmp(end - 4, ".git", 4))
 183                         end -= 4;
 184         }
 185
 186         if (is_bare) {
 187                 struct strbuf result = STRBUF_INIT;
 188                 strbuf_addf(&result, "%.*s.git", (int)(end - start), start);
 189                 dir = strbuf_detach(&result, NULL);
 190         } else
 191                 dir = xstrndup(start, end - start);
 192         /*
 193          * Replace sequences of 'control' characters and whitespace
 194          * with one ascii space, remove leading and trailing spaces.
 195          */
 196         if (*dir) {
 197                 char *out = dir;
 198                 int prev_space = 1 /* strip leading whitespace */;
 199                 for (end = dir; *end; ++end) {
 200                         char ch = *end;
 201                         if ((unsigned char)ch < '\x20')
 202                                 ch = '\x20';
 203                         if (isspace(ch)) {
 204                                 if (prev_space)
 205                                         continue;
 206                                 prev_space = 1;
 207                         } else
 208                                 prev_space = 0;
 209                         *out++ = ch;
 210                 }
 211                 *out = '\0';
 212                 if (out > dir && prev_space)
 213                         out[-1] = '\0';
 214         }
 215         return dir;
 216 }
 217
 218 static void strip_trailing_slashes(char *dir)
 219 {
 220         char *end = dir + strlen(dir);
 221
 222         while (dir < end - 1 && is_dir_sep(end[-1]))
 223                 end--;
 224         *end = '\0';
 225 }
 226
 227 static int add_one_reference(struct string_list_item *item, void *cb_data)
 228 {
 229         char *ref_git;
 230         struct strbuf alternate = STRBUF_INIT;
 231         struct remote *remote;
 232         struct transport *transport;
 233         const struct ref *extra;
 234
 235         /* Beware: real_path() and mkpath() return static buffer */
 236         ref_git = xstrdup(real_path(item->string));
 237         if (is_directory(mkpath("%s/.git/objects", ref_git))) {
 238                 char *ref_git_git = xstrdup(mkpath("%s/.git", ref_git));
 239                 free(ref_git);
 240                 ref_git = ref_git_git;
 241         } else if (!is_directory(mkpath("%s/objects", ref_git)))
 242                 die(_("reference repository '%s' is not a local directory."),
 243                     item->string);
 244
 245         strbuf_addf(&alternate, "%s/objects", ref_git);
 246         add_to_alternates_file(alternate.buf);
 247         strbuf_release(&alternate);
 248
 249         remote = remote_get(ref_git);
 250         transport = transport_get(remote, ref_git);
 251         for (extra = transport_get_remote_refs(transport); extra;
 252              extra = extra->next)
 253                 add_extra_ref(extra->name, extra->old_sha1, 0);
 254
 255         transport_disconnect(transport);
 256         free(ref_git);
 257         return 0;
 258 }
 259
 260 static void setup_reference(void)
 261 {
 262         for_each_string_list(&option_reference, add_one_reference, NULL);
 263 }
 264
 265 static void copy_alternates(struct strbuf *src, struct strbuf *dst,
 266                             const char *src_repo)
 267 {
 268         /*
 269          * Read from the source objects/info/alternates file
 270          * and copy the entries to corresponding file in the
 271          * destination repository with add_to_alternates_file().
 272          * Both src and dst have "$path/objects/info/alternates".
 273          *
 274          * Instead of copying bit-for-bit from the original,
 275          * we need to append to existing one so that the already
 276          * created entry via "clone -s" is not lost, and also
 277          * to turn entries with paths relative to the original
 278          * absolute, so that they can be used in the new repository.
 279          */
 280         FILE *in = fopen(src->buf, "r");
 281         struct strbuf line = STRBUF_INIT;
 282
 283         while (strbuf_getline(&line, in, '\n') != EOF) {
 284                 char *abs_path, abs_buf[PATH_MAX];
 285                 if (!line.len || line.buf[0] == '#')
 286                         continue;
 287                 if (is_absolute_path(line.buf)) {
 288                         add_to_alternates_file(line.buf);
 289                         continue;
 290                 }
 291                 abs_path = mkpath("%s/objects/%s", src_repo, line.buf);
 292                 normalize_path_copy(abs_buf, abs_path);
 293                 add_to_alternates_file(abs_buf);
 294         }
 295         strbuf_release(&line);
 296         fclose(in);
 297 }
 298
 299 static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
 300                                    const char *src_repo, int src_baselen)
 301 {
 302         struct dirent *de;
 303         struct stat buf;
 304         int src_len, dest_len;
 305         DIR *dir;
 306
 307         dir = opendir(src->buf);
 308         if (!dir)
 309                 die_errno(_("failed to open '%s'"), src->buf);
 310
 311         if (mkdir(dest->buf, 0777)) {
 312                 if (errno != EEXIST)
 313                         die_errno(_("failed to create directory '%s'"), dest->buf);
 314                 else if (stat(dest->buf, &buf))
 315                         die_errno(_("failed to stat '%s'"), dest->buf);
 316                 else if (!S_ISDIR(buf.st_mode))
 317                         die(_("%s exists and is not a directory"), dest->buf);
 318         }
 319
 320         strbuf_addch(src, '/');
 321         src_len = src->len;
 322         strbuf_addch(dest, '/');
 323         dest_len = dest->len;
 324
 325         while ((de = readdir(dir)) != NULL) {
 326                 strbuf_setlen(src, src_len);
 327                 strbuf_addstr(src, de->d_name);
 328                 strbuf_setlen(dest, dest_len);
 329                 strbuf_addstr(dest, de->d_name);
 330                 if (stat(src->buf, &buf)) {
 331                         warning (_("failed to stat %s\n"), src->buf);
 332                         continue;
 333                 }
 334                 if (S_ISDIR(buf.st_mode)) {
 335                         if (de->d_name[0] != '.')
 336                                 copy_or_link_directory(src, dest,
 337                                                        src_repo, src_baselen);
 338                         continue;
 339                 }
 340
 341                 /* Files that cannot be copied bit-for-bit... */
 342                 if (!strcmp(src->buf + src_baselen, "/info/alternates")) {
 343                         copy_alternates(src, dest, src_repo);
 344                         continue;
 345                 }
 346
 347                 if (unlink(dest->buf) && errno != ENOENT)
 348                         die_errno(_("failed to unlink '%s'"), dest->buf);
 349                 if (!option_no_hardlinks) {
 350                         if (!link(src->buf, dest->buf))
 351                                 continue;
 352                         if (option_local)
 353                                 die_errno(_("failed to create link '%s'"), dest->buf);
 354                         option_no_hardlinks = 1;
 355                 }
 356                 if (copy_file_with_time(dest->buf, src->buf, 0666))
 357                         die_errno(_("failed to copy file to '%s'"), dest->buf);
 358         }
 359         closedir(dir);
 360 }
 361
 362 static const struct ref *clone_local(const char *src_repo,
 363                                      const char *dest_repo)
 364 {
 365         const struct ref *ret;
 366         struct remote *remote;
 367         struct transport *transport;
 368
 369         if (option_shared) {
 370                 struct strbuf alt = STRBUF_INIT;
 371                 strbuf_addf(&alt, "%s/objects", src_repo);
 372                 add_to_alternates_file(alt.buf);
 373                 strbuf_release(&alt);
 374         } else {
 375                 struct strbuf src = STRBUF_INIT;
 376                 struct strbuf dest = STRBUF_INIT;
 377                 strbuf_addf(&src, "%s/objects", src_repo);
 378                 strbuf_addf(&dest, "%s/objects", dest_repo);
 379                 copy_or_link_directory(&src, &dest, src_repo, src.len);
 380                 strbuf_release(&src);
 381                 strbuf_release(&dest);
 382         }
 383
 384         remote = remote_get(src_repo);
 385         transport = transport_get(remote, src_repo);
 386         ret = transport_get_remote_refs(transport);
 387         transport_disconnect(transport);
 388         if (0 <= option_verbosity)
 389                 printf(_("done.\n"));
 390         return ret;
 391 }
 392
 393 static const char *junk_work_tree;
 394 static const char *junk_git_dir;
 395 static pid_t junk_pid;
 396
 397 static void remove_junk(void)
 398 {
 399         struct strbuf sb = STRBUF_INIT;
 400         if (getpid() != junk_pid)
 401                 return;
 402         if (junk_git_dir) {
 403                 strbuf_addstr(&sb, junk_git_dir);
 404                 remove_dir_recursively(&sb, 0);
 405                 strbuf_reset(&sb);
 406         }
 407         if (junk_work_tree) {
 408                 strbuf_addstr(&sb, junk_work_tree);
 409                 remove_dir_recursively(&sb, 0);
 410                 strbuf_reset(&sb);
 411         }
 412 }
 413
 414 static void remove_junk_on_signal(int signo)
 415 {
 416         remove_junk();
 417         sigchain_pop(signo);
 418         raise(signo);
 419 }
 420
 421 static struct ref *wanted_peer_refs(const struct ref *refs,
 422                 struct refspec *refspec)
 423 {
 424         struct ref *local_refs = NULL;
 425         struct ref **tail = &local_refs;
 426
 427         get_fetch_map(refs, refspec, &tail, 0);
 428         if (!option_mirror)
 429                 get_fetch_map(refs, tag_refspec, &tail, 0);
 430
 431         return local_refs;
 432 }
 433
 434 static void write_remote_refs(const struct ref *local_refs)
 435 {
 436         const struct ref *r;
 437
 438         for (r = local_refs; r; r = r->next)
 439                 add_extra_ref(r->peer_ref->name, r->old_sha1, 0);
 440
 441         pack_refs(PACK_REFS_ALL);
 442         clear_extra_refs();
 443 }
 444
 445 int cmd_clone(int argc, const char **argv, const char *prefix)
 446 {
 447         int is_bundle = 0, is_local;
 448         struct stat buf;
 449         const char *repo_name, *repo, *work_tree, *git_dir;
 450         char *path, *dir;
 451         int dest_exists;
 452         const struct ref *refs, *remote_head;
 453         const struct ref *remote_head_points_at;
 454         const struct ref *our_head_points_at;
 455         struct ref *mapped_refs;
 456         struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
 457         struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
 458         struct transport *transport = NULL;
 459         char *src_ref_prefix = "refs/heads/";
 460         int err = 0;
 461
 462         struct refspec *refspec;
 463         const char *fetch_pattern;
 464
 465         junk_pid = getpid();
 466
 467         packet_trace_identity("clone");
 468         argc = parse_options(argc, argv, prefix, builtin_clone_options,
 469                              builtin_clone_usage, 0);
 470
 471         if (argc > 2)
 472                 usage_msg_opt(_("Too many arguments."),
 473                         builtin_clone_usage, builtin_clone_options);
 474
 475         if (argc == 0)
 476                 usage_msg_opt(_("You must specify a repository to clone."),
 477                         builtin_clone_usage, builtin_clone_options);
 478
 479         if (option_mirror)
 480                 option_bare = 1;
 481
 482         if (option_bare) {
 483                 if (option_origin)
 484                         die(_("--bare and --origin %s options are incompatible."),
 485                             option_origin);
 486                 option_no_checkout = 1;
 487         }
 488
 489         if (!option_origin)
 490                 option_origin = "origin";
 491
 492         repo_name = argv[0];
 493
 494         path = get_repo_path(repo_name, &is_bundle);
 495         if (path)
 496                 repo = xstrdup(absolute_path(repo_name));
 497         else if (!strchr(repo_name, ':'))
 498                 die(_("repository '%s' does not exist"), repo_name);
 499         else
 500                 repo = repo_name;
 501         is_local = path && !is_bundle;
 502         if (is_local && option_depth)
 503                 warning(_("--depth is ignored in local clones; use file:// instead."));
 504
 505         if (argc == 2)
 506                 dir = xstrdup(argv[1]);
 507         else
 508                 dir = guess_dir_name(repo_name, is_bundle, option_bare);
 509         strip_trailing_slashes(dir);
 510
 511         dest_exists = !stat(dir, &buf);
 512         if (dest_exists && !is_empty_dir(dir))
 513                 die(_("destination path '%s' already exists and is not "
 514                         "an empty directory."), dir);
 515
 516         strbuf_addf(&reflog_msg, "clone: from %s", repo);
 517
 518         if (option_bare)
 519                 work_tree = NULL;
 520         else {
 521                 work_tree = getenv("GIT_WORK_TREE");
 522                 if (work_tree && !stat(work_tree, &buf))
 523                         die(_("working tree '%s' already exists."), work_tree);
 524         }
 525
 526         if (option_bare || work_tree)
 527                 git_dir = xstrdup(dir);
 528         else {
 529                 work_tree = dir;
 530                 git_dir = xstrdup(mkpath("%s/.git", dir));
 531         }
 532
 533         if (!option_bare) {
 534                 junk_work_tree = work_tree;
 535                 if (safe_create_leading_directories_const(work_tree) < 0)
 536                         die_errno(_("could not create leading directories of '%s'"),
 537                                   work_tree);
 538                 if (!dest_exists && mkdir(work_tree, 0755))
 539                         die_errno(_("could not create work tree dir '%s'."),
 540                                   work_tree);
 541                 set_git_work_tree(work_tree);
 542         }
 543         junk_git_dir = git_dir;
 544         atexit(remove_junk);
 545         sigchain_push_common(remove_junk_on_signal);
 546
 547         setenv(CONFIG_ENVIRONMENT, mkpath("%s/config", git_dir), 1);
 548
 549         if (safe_create_leading_directories_const(git_dir) < 0)
 550                 die(_("could not create leading directories of '%s'"), git_dir);
 551
 552         set_git_dir_init(git_dir, real_git_dir, 0);
 553         if (real_git_dir)
 554                 git_dir = real_git_dir;
 555
 556         if (0 <= option_verbosity) {
 557                 if (option_bare)
 558                         printf(_("Cloning into bare repository %s...\n"), dir);
 559                 else
 560                         printf(_("Cloning into %s...\n"), dir);
 561         }
 562         init_db(option_template, INIT_DB_QUIET);
 563
 564         /*
 565          * At this point, the config exists, so we do not need the
 566          * environment variable.  We actually need to unset it, too, to
 567          * re-enable parsing of the global configs.
 568          */
 569         unsetenv(CONFIG_ENVIRONMENT);
 570
 571         git_config(git_default_config, NULL);
 572
 573         if (option_bare) {
 574                 if (option_mirror)
 575                         src_ref_prefix = "refs/";
 576                 strbuf_addstr(&branch_top, src_ref_prefix);
 577
 578                 git_config_set("core.bare", "true");
 579         } else {
 580                 strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
 581         }
 582
 583         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
 584
 585         if (option_mirror || !option_bare) {
 586                 /* Configure the remote */
 587                 strbuf_addf(&key, "remote.%s.fetch", option_origin);
 588                 git_config_set_multivar(key.buf, value.buf, "^$", 0);
 589                 strbuf_reset(&key);
 590
 591                 if (option_mirror) {
 592                         strbuf_addf(&key, "remote.%s.mirror", option_origin);
 593                         git_config_set(key.buf, "true");
 594                         strbuf_reset(&key);
 595                 }
 596         }
 597
 598         strbuf_addf(&key, "remote.%s.url", option_origin);
 599         git_config_set(key.buf, repo);
 600         strbuf_reset(&key);
 601
 602         if (option_reference.nr)
 603                 setup_reference();
 604
 605         fetch_pattern = value.buf;
 606         refspec = parse_fetch_refspec(1, &fetch_pattern);
 607
 608         strbuf_reset(&value);
 609
 610         if (is_local) {
 611                 refs = clone_local(path, git_dir);
 612                 mapped_refs = wanted_peer_refs(refs, refspec);
 613         } else {
 614                 struct remote *remote = remote_get(option_origin);
 615                 transport = transport_get(remote, remote->url[0]);
 616
 617                 if (!transport->get_refs_list || !transport->fetch)
 618                         die(_("Don't know how to clone %s"), transport->url);
 619
 620                 transport_set_option(transport, TRANS_OPT_KEEP, "yes");
 621
 622                 if (option_depth)
 623                         transport_set_option(transport, TRANS_OPT_DEPTH,
 624                                              option_depth);
 625
 626                 transport_set_verbosity(transport, option_verbosity, option_progress);
 627
 628                 if (option_upload_pack)
 629                         transport_set_option(transport, TRANS_OPT_UPLOADPACK,
 630                                              option_upload_pack);
 631
 632                 refs = transport_get_remote_refs(transport);
 633                 if (refs) {
 634                         mapped_refs = wanted_peer_refs(refs, refspec);
 635                         transport_fetch_refs(transport, mapped_refs);
 636                 }
 637         }
 638
 639         if (refs) {
 640                 clear_extra_refs();
 641
 642                 write_remote_refs(mapped_refs);
 643
 644                 remote_head = find_ref_by_name(refs, "HEAD");
 645                 remote_head_points_at =
 646                         guess_remote_head(remote_head, mapped_refs, 0);
 647
 648                 if (option_branch) {
 649                         struct strbuf head = STRBUF_INIT;
 650                         strbuf_addstr(&head, src_ref_prefix);
 651                         strbuf_addstr(&head, option_branch);
 652                         our_head_points_at =
 653                                 find_ref_by_name(mapped_refs, head.buf);
 654                         strbuf_release(&head);
 655
 656                         if (!our_head_points_at) {
 657                                 warning(_("Remote branch %s not found in "
 658                                         "upstream %s, using HEAD instead"),
 659                                         option_branch, option_origin);
 660                                 our_head_points_at = remote_head_points_at;
 661                         }
 662                 }
 663                 else
 664                         our_head_points_at = remote_head_points_at;
 665         }
 666         else {
 667                 warning(_("You appear to have cloned an empty repository."));
 668                 our_head_points_at = NULL;
 669                 remote_head_points_at = NULL;
 670                 remote_head = NULL;
 671                 option_no_checkout = 1;
 672                 if (!option_bare)
 673                         install_branch_config(0, "master", option_origin,
 674                                               "refs/heads/master");
 675         }
 676
 677         if (remote_head_points_at && !option_bare) {
 678                 struct strbuf head_ref = STRBUF_INIT;
 679                 strbuf_addstr(&head_ref, branch_top.buf);
 680                 strbuf_addstr(&head_ref, "HEAD");
 681                 create_symref(head_ref.buf,
 682                               remote_head_points_at->peer_ref->name,
 683                               reflog_msg.buf);
 684         }
 685
 686         if (our_head_points_at) {
 687                 /* Local default branch link */
 688                 create_symref("HEAD", our_head_points_at->name, NULL);
 689                 if (!option_bare) {
 690                         const char *head = skip_prefix(our_head_points_at->name,
 691                                                        "refs/heads/");
 692                         update_ref(reflog_msg.buf, "HEAD",
 693                                    our_head_points_at->old_sha1,
 694                                    NULL, 0, DIE_ON_ERR);
 695                         install_branch_config(0, head, option_origin,
 696                                               our_head_points_at->name);
 697                 }
 698         } else if (remote_head) {
 699                 /* Source had detached HEAD pointing somewhere. */
 700                 if (!option_bare) {
 701                         update_ref(reflog_msg.buf, "HEAD",
 702                                    remote_head->old_sha1,
 703                                    NULL, REF_NODEREF, DIE_ON_ERR);
 704                         our_head_points_at = remote_head;
 705                 }
 706         } else {
 707                 /* Nothing to checkout out */
 708                 if (!option_no_checkout)
 709                         warning(_("remote HEAD refers to nonexistent ref, "
 710                                 "unable to checkout.\n"));
 711                 option_no_checkout = 1;
 712         }
 713
 714         if (transport) {
 715                 transport_unlock_pack(transport);
 716                 transport_disconnect(transport);
 717         }
 718
 719         if (!option_no_checkout) {
 720                 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
 721                 struct unpack_trees_options opts;
 722                 struct tree *tree;
 723                 struct tree_desc t;
 724                 int fd;
 725
 726                 /* We need to be in the new work tree for the checkout */
 727                 setup_work_tree();
 728
 729                 fd = hold_locked_index(lock_file, 1);
 730
 731                 memset(&opts, 0, sizeof opts);
 732                 opts.update = 1;
 733                 opts.merge = 1;
 734                 opts.fn = oneway_merge;
 735                 opts.verbose_update = (option_verbosity > 0);
 736                 opts.src_index = &the_index;
 737                 opts.dst_index = &the_index;
 738
 739                 tree = parse_tree_indirect(our_head_points_at->old_sha1);
 740                 parse_tree(tree);
 741                 init_tree_desc(&t, tree->buffer, tree->size);
 742                 unpack_trees(1, &t, &opts);
 743
 744                 if (write_cache(fd, active_cache, active_nr) ||
 745                     commit_locked_index(lock_file))
 746                         die(_("unable to write new index file"));
 747
 748                 err |= run_hook(NULL, "post-checkout", sha1_to_hex(null_sha1),
 749                                 sha1_to_hex(our_head_points_at->old_sha1), "1",
 750                                 NULL);
 751
 752                 if (!err && option_recursive)
 753                         err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
 754         }
 755
 756         strbuf_release(&reflog_msg);
 757         strbuf_release(&branch_top);
 758         strbuf_release(&key);
 759         strbuf_release(&value);
 760         junk_pid = 0;
 761         return err;
 762 }