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 #define USE_THE_INDEX_COMPATIBILITY_MACROS
  12 #include "builtin.h"
  13 #include "config.h"
  14 #include "lockfile.h"
  15 #include "parse-options.h"
  16 #include "fetch-pack.h"
  17 #include "refs.h"
  18 #include "refspec.h"
  19 #include "object-store.h"
  20 #include "tree.h"
  21 #include "tree-walk.h"
  22 #include "unpack-trees.h"
  23 #include "transport.h"
  24 #include "strbuf.h"
  25 #include "dir.h"
  26 #include "dir-iterator.h"
  27 #include "iterator.h"
  28 #include "sigchain.h"
  29 #include "branch.h"
  30 #include "remote.h"
  31 #include "run-command.h"
  32 #include "connected.h"
  33 #include "packfile.h"
  34 #include "list-objects-filter-options.h"
  35
  36 /*
  37  * Overall FIXMEs:
  38  *  - respect DB_ENVIRONMENT for .git/objects.
  39  *
  40  * Implementation notes:
  41  *  - dropping use-separate-remote and no-separate-remote compatibility
  42  *
  43  */
  44 static const char * const builtin_clone_usage[] = {
  45         N_("git clone [<options>] [--] <repo> [<dir>]"),
  46         NULL
  47 };
  48
  49 static int option_no_checkout, option_bare, option_mirror, option_single_branch = -1;
  50 static int option_local = -1, option_no_hardlinks, option_shared;
  51 static int option_no_tags;
  52 static int option_shallow_submodules;
  53 static int deepen;
  54 static char *option_template, *option_depth, *option_since;
  55 static char *option_origin = NULL;
  56 static char *remote_name = NULL;
  57 static char *option_branch = NULL;
  58 static struct string_list option_not = STRING_LIST_INIT_NODUP;
  59 static const char *real_git_dir;
  60 static char *option_upload_pack = "git-upload-pack";
  61 static int option_verbosity;
  62 static int option_progress = -1;
  63 static int option_sparse_checkout;
  64 static enum transport_family family;
  65 static struct string_list option_config = STRING_LIST_INIT_NODUP;
  66 static struct string_list option_required_reference = STRING_LIST_INIT_NODUP;
  67 static struct string_list option_optional_reference = STRING_LIST_INIT_NODUP;
  68 static int option_dissociate;
  69 static int max_jobs = -1;
  70 static struct string_list option_recurse_submodules = STRING_LIST_INIT_NODUP;
  71 static struct list_objects_filter_options filter_options;
  72 static struct string_list server_options = STRING_LIST_INIT_NODUP;
  73 static int option_remote_submodules;
  74
  75 static int recurse_submodules_cb(const struct option *opt,
  76                                  const char *arg, int unset)
  77 {
  78         if (unset)
  79                 string_list_clear((struct string_list *)opt->value, 0);
  80         else if (arg)
  81                 string_list_append((struct string_list *)opt->value, arg);
  82         else
  83                 string_list_append((struct string_list *)opt->value,
  84                                    (const char *)opt->defval);
  85
  86         return 0;
  87 }
  88
  89 static struct option builtin_clone_options[] = {
  90         OPT__VERBOSITY(&option_verbosity),
  91         OPT_BOOL(0, "progress", &option_progress,
  92                  N_("force progress reporting")),
  93         OPT_BOOL('n', "no-checkout", &option_no_checkout,
  94                  N_("don't create a checkout")),
  95         OPT_BOOL(0, "bare", &option_bare, N_("create a bare repository")),
  96         OPT_HIDDEN_BOOL(0, "naked", &option_bare,
  97                         N_("create a bare repository")),
  98         OPT_BOOL(0, "mirror", &option_mirror,
  99                  N_("create a mirror repository (implies bare)")),
 100         OPT_BOOL('l', "local", &option_local,
 101                 N_("to clone from a local repository")),
 102         OPT_BOOL(0, "no-hardlinks", &option_no_hardlinks,
 103                     N_("don't use local hardlinks, always copy")),
 104         OPT_BOOL('s', "shared", &option_shared,
 105                     N_("setup as shared repository")),
 106         { OPTION_CALLBACK, 0, "recurse-submodules", &option_recurse_submodules,
 107           N_("pathspec"), N_("initialize submodules in the clone"),
 108           PARSE_OPT_OPTARG, recurse_submodules_cb, (intptr_t)"." },
 109         OPT_ALIAS(0, "recursive", "recurse-submodules"),
 110         OPT_INTEGER('j', "jobs", &max_jobs,
 111                     N_("number of submodules cloned in parallel")),
 112         OPT_STRING(0, "template", &option_template, N_("template-directory"),
 113                    N_("directory from which templates will be used")),
 114         OPT_STRING_LIST(0, "reference", &option_required_reference, N_("repo"),
 115                         N_("reference repository")),
 116         OPT_STRING_LIST(0, "reference-if-able", &option_optional_reference,
 117                         N_("repo"), N_("reference repository")),
 118         OPT_BOOL(0, "dissociate", &option_dissociate,
 119                  N_("use --reference only while cloning")),
 120         OPT_STRING('o', "origin", &option_origin, N_("name"),
 121                    N_("use <name> instead of 'origin' to track upstream")),
 122         OPT_STRING('b', "branch", &option_branch, N_("branch"),
 123                    N_("checkout <branch> instead of the remote's HEAD")),
 124         OPT_STRING('u', "upload-pack", &option_upload_pack, N_("path"),
 125                    N_("path to git-upload-pack on the remote")),
 126         OPT_STRING(0, "depth", &option_depth, N_("depth"),
 127                     N_("create a shallow clone of that depth")),
 128         OPT_STRING(0, "shallow-since", &option_since, N_("time"),
 129                     N_("create a shallow clone since a specific time")),
 130         OPT_STRING_LIST(0, "shallow-exclude", &option_not, N_("revision"),
 131                         N_("deepen history of shallow clone, excluding rev")),
 132         OPT_BOOL(0, "single-branch", &option_single_branch,
 133                     N_("clone only one branch, HEAD or --branch")),
 134         OPT_BOOL(0, "no-tags", &option_no_tags,
 135                  N_("don't clone any tags, and make later fetches not to follow them")),
 136         OPT_BOOL(0, "shallow-submodules", &option_shallow_submodules,
 137                     N_("any cloned submodules will be shallow")),
 138         OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
 139                    N_("separate git dir from working tree")),
 140         OPT_STRING_LIST('c', "config", &option_config, N_("key=value"),
 141                         N_("set config inside the new repository")),
 142         OPT_STRING_LIST(0, "server-option", &server_options,
 143                         N_("server-specific"), N_("option to transmit")),
 144         OPT_SET_INT('4', "ipv4", &family, N_("use IPv4 addresses only"),
 145                         TRANSPORT_FAMILY_IPV4),
 146         OPT_SET_INT('6', "ipv6", &family, N_("use IPv6 addresses only"),
 147                         TRANSPORT_FAMILY_IPV6),
 148         OPT_PARSE_LIST_OBJECTS_FILTER(&filter_options),
 149         OPT_BOOL(0, "remote-submodules", &option_remote_submodules,
 150                     N_("any cloned submodules will use their remote-tracking branch")),
 151         OPT_BOOL(0, "sparse", &option_sparse_checkout,
 152                     N_("initialize sparse-checkout file to include only files at root")),
 153         OPT_END()
 154 };
 155
 156 static const char *get_repo_path_1(struct strbuf *path, int *is_bundle)
 157 {
 158         static char *suffix[] = { "/.git", "", ".git/.git", ".git" };
 159         static char *bundle_suffix[] = { ".bundle", "" };
 160         size_t baselen = path->len;
 161         struct stat st;
 162         int i;
 163
 164         for (i = 0; i < ARRAY_SIZE(suffix); i++) {
 165                 strbuf_setlen(path, baselen);
 166                 strbuf_addstr(path, suffix[i]);
 167                 if (stat(path->buf, &st))
 168                         continue;
 169                 if (S_ISDIR(st.st_mode) && is_git_directory(path->buf)) {
 170                         *is_bundle = 0;
 171                         return path->buf;
 172                 } else if (S_ISREG(st.st_mode) && st.st_size > 8) {
 173                         /* Is it a "gitfile"? */
 174                         char signature[8];
 175                         const char *dst;
 176                         int len, fd = open(path->buf, O_RDONLY);
 177                         if (fd < 0)
 178                                 continue;
 179                         len = read_in_full(fd, signature, 8);
 180                         close(fd);
 181                         if (len != 8 || strncmp(signature, "gitdir: ", 8))
 182                                 continue;
 183                         dst = read_gitfile(path->buf);
 184                         if (dst) {
 185                                 *is_bundle = 0;
 186                                 return dst;
 187                         }
 188                 }
 189         }
 190
 191         for (i = 0; i < ARRAY_SIZE(bundle_suffix); i++) {
 192                 strbuf_setlen(path, baselen);
 193                 strbuf_addstr(path, bundle_suffix[i]);
 194                 if (!stat(path->buf, &st) && S_ISREG(st.st_mode)) {
 195                         *is_bundle = 1;
 196                         return path->buf;
 197                 }
 198         }
 199
 200         return NULL;
 201 }
 202
 203 static char *get_repo_path(const char *repo, int *is_bundle)
 204 {
 205         struct strbuf path = STRBUF_INIT;
 206         const char *raw;
 207         char *canon;
 208
 209         strbuf_addstr(&path, repo);
 210         raw = get_repo_path_1(&path, is_bundle);
 211         canon = raw ? absolute_pathdup(raw) : NULL;
 212         strbuf_release(&path);
 213         return canon;
 214 }
 215
 216 static char *guess_dir_name(const char *repo, int is_bundle, int is_bare)
 217 {
 218         const char *end = repo + strlen(repo), *start, *ptr;
 219         size_t len;
 220         char *dir;
 221
 222         /*
 223          * Skip scheme.
 224          */
 225         start = strstr(repo, "://");
 226         if (start == NULL)
 227                 start = repo;
 228         else
 229                 start += 3;
 230
 231         /*
 232          * Skip authentication data. The stripping does happen
 233          * greedily, such that we strip up to the last '@' inside
 234          * the host part.
 235          */
 236         for (ptr = start; ptr < end && !is_dir_sep(*ptr); ptr++) {
 237                 if (*ptr == '@')
 238                         start = ptr + 1;
 239         }
 240
 241         /*
 242          * Strip trailing spaces, slashes and /.git
 243          */
 244         while (start < end && (is_dir_sep(end[-1]) || isspace(end[-1])))
 245                 end--;
 246         if (end - start > 5 && is_dir_sep(end[-5]) &&
 247             !strncmp(end - 4, ".git", 4)) {
 248                 end -= 5;
 249                 while (start < end && is_dir_sep(end[-1]))
 250                         end--;
 251         }
 252
 253         /*
 254          * Strip trailing port number if we've got only a
 255          * hostname (that is, there is no dir separator but a
 256          * colon). This check is required such that we do not
 257          * strip URI's like '/foo/bar:2222.git', which should
 258          * result in a dir '2222' being guessed due to backwards
 259          * compatibility.
 260          */
 261         if (memchr(start, '/', end - start) == NULL
 262             && memchr(start, ':', end - start) != NULL) {
 263                 ptr = end;
 264                 while (start < ptr && isdigit(ptr[-1]) && ptr[-1] != ':')
 265                         ptr--;
 266                 if (start < ptr && ptr[-1] == ':')
 267                         end = ptr - 1;
 268         }
 269
 270         /*
 271          * Find last component. To remain backwards compatible we
 272          * also regard colons as path separators, such that
 273          * cloning a repository 'foo:bar.git' would result in a
 274          * directory 'bar' being guessed.
 275          */
 276         ptr = end;
 277         while (start < ptr && !is_dir_sep(ptr[-1]) && ptr[-1] != ':')
 278                 ptr--;
 279         start = ptr;
 280
 281         /*
 282          * Strip .{bundle,git}.
 283          */
 284         len = end - start;
 285         strip_suffix_mem(start, &len, is_bundle ? ".bundle" : ".git");
 286
 287         if (!len || (len == 1 && *start == '/'))
 288                 die(_("No directory name could be guessed.\n"
 289                       "Please specify a directory on the command line"));
 290
 291         if (is_bare)
 292                 dir = xstrfmt("%.*s.git", (int)len, start);
 293         else
 294                 dir = xstrndup(start, len);
 295         /*
 296          * Replace sequences of 'control' characters and whitespace
 297          * with one ascii space, remove leading and trailing spaces.
 298          */
 299         if (*dir) {
 300                 char *out = dir;
 301                 int prev_space = 1 /* strip leading whitespace */;
 302                 for (end = dir; *end; ++end) {
 303                         char ch = *end;
 304                         if ((unsigned char)ch < '\x20')
 305                                 ch = '\x20';
 306                         if (isspace(ch)) {
 307                                 if (prev_space)
 308                                         continue;
 309                                 prev_space = 1;
 310                         } else
 311                                 prev_space = 0;
 312                         *out++ = ch;
 313                 }
 314                 *out = '\0';
 315                 if (out > dir && prev_space)
 316                         out[-1] = '\0';
 317         }
 318         return dir;
 319 }
 320
 321 static void strip_trailing_slashes(char *dir)
 322 {
 323         char *end = dir + strlen(dir);
 324
 325         while (dir < end - 1 && is_dir_sep(end[-1]))
 326                 end--;
 327         *end = '\0';
 328 }
 329
 330 static int add_one_reference(struct string_list_item *item, void *cb_data)
 331 {
 332         struct strbuf err = STRBUF_INIT;
 333         int *required = cb_data;
 334         char *ref_git = compute_alternate_path(item->string, &err);
 335
 336         if (!ref_git) {
 337                 if (*required)
 338                         die("%s", err.buf);
 339                 else
 340                         fprintf(stderr,
 341                                 _("info: Could not add alternate for '%s': %s\n"),
 342                                 item->string, err.buf);
 343         } else {
 344                 struct strbuf sb = STRBUF_INIT;
 345                 strbuf_addf(&sb, "%s/objects", ref_git);
 346                 add_to_alternates_file(sb.buf);
 347                 strbuf_release(&sb);
 348         }
 349
 350         strbuf_release(&err);
 351         free(ref_git);
 352         return 0;
 353 }
 354
 355 static void setup_reference(void)
 356 {
 357         int required = 1;
 358         for_each_string_list(&option_required_reference,
 359                              add_one_reference, &required);
 360         required = 0;
 361         for_each_string_list(&option_optional_reference,
 362                              add_one_reference, &required);
 363 }
 364
 365 static void copy_alternates(struct strbuf *src, const char *src_repo)
 366 {
 367         /*
 368          * Read from the source objects/info/alternates file
 369          * and copy the entries to corresponding file in the
 370          * destination repository with add_to_alternates_file().
 371          * Both src and dst have "$path/objects/info/alternates".
 372          *
 373          * Instead of copying bit-for-bit from the original,
 374          * we need to append to existing one so that the already
 375          * created entry via "clone -s" is not lost, and also
 376          * to turn entries with paths relative to the original
 377          * absolute, so that they can be used in the new repository.
 378          */
 379         FILE *in = xfopen(src->buf, "r");
 380         struct strbuf line = STRBUF_INIT;
 381
 382         while (strbuf_getline(&line, in) != EOF) {
 383                 char *abs_path;
 384                 if (!line.len || line.buf[0] == '#')
 385                         continue;
 386                 if (is_absolute_path(line.buf)) {
 387                         add_to_alternates_file(line.buf);
 388                         continue;
 389                 }
 390                 abs_path = mkpathdup("%s/objects/%s", src_repo, line.buf);
 391                 if (!normalize_path_copy(abs_path, abs_path))
 392                         add_to_alternates_file(abs_path);
 393                 else
 394                         warning("skipping invalid relative alternate: %s/%s",
 395                                 src_repo, line.buf);
 396                 free(abs_path);
 397         }
 398         strbuf_release(&line);
 399         fclose(in);
 400 }
 401
 402 static void mkdir_if_missing(const char *pathname, mode_t mode)
 403 {
 404         struct stat st;
 405
 406         if (!mkdir(pathname, mode))
 407                 return;
 408
 409         if (errno != EEXIST)
 410                 die_errno(_("failed to create directory '%s'"), pathname);
 411         else if (stat(pathname, &st))
 412                 die_errno(_("failed to stat '%s'"), pathname);
 413         else if (!S_ISDIR(st.st_mode))
 414                 die(_("%s exists and is not a directory"), pathname);
 415 }
 416
 417 static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
 418                                    const char *src_repo)
 419 {
 420         int src_len, dest_len;
 421         struct dir_iterator *iter;
 422         int iter_status;
 423         unsigned int flags;
 424         struct strbuf realpath = STRBUF_INIT;
 425
 426         mkdir_if_missing(dest->buf, 0777);
 427
 428         flags = DIR_ITERATOR_PEDANTIC | DIR_ITERATOR_FOLLOW_SYMLINKS;
 429         iter = dir_iterator_begin(src->buf, flags);
 430
 431         if (!iter)
 432                 die_errno(_("failed to start iterator over '%s'"), src->buf);
 433
 434         strbuf_addch(src, '/');
 435         src_len = src->len;
 436         strbuf_addch(dest, '/');
 437         dest_len = dest->len;
 438
 439         while ((iter_status = dir_iterator_advance(iter)) == ITER_OK) {
 440                 strbuf_setlen(src, src_len);
 441                 strbuf_addstr(src, iter->relative_path);
 442                 strbuf_setlen(dest, dest_len);
 443                 strbuf_addstr(dest, iter->relative_path);
 444
 445                 if (S_ISDIR(iter->st.st_mode)) {
 446                         mkdir_if_missing(dest->buf, 0777);
 447                         continue;
 448                 }
 449
 450                 /* Files that cannot be copied bit-for-bit... */
 451                 if (!fspathcmp(iter->relative_path, "info/alternates")) {
 452                         copy_alternates(src, src_repo);
 453                         continue;
 454                 }
 455
 456                 if (unlink(dest->buf) && errno != ENOENT)
 457                         die_errno(_("failed to unlink '%s'"), dest->buf);
 458                 if (!option_no_hardlinks) {
 459                         strbuf_realpath(&realpath, src->buf, 1);
 460                         if (!link(realpath.buf, dest->buf))
 461                                 continue;
 462                         if (option_local > 0)
 463                                 die_errno(_("failed to create link '%s'"), dest->buf);
 464                         option_no_hardlinks = 1;
 465                 }
 466                 if (copy_file_with_time(dest->buf, src->buf, 0666))
 467                         die_errno(_("failed to copy file to '%s'"), dest->buf);
 468         }
 469
 470         if (iter_status != ITER_DONE) {
 471                 strbuf_setlen(src, src_len);
 472                 die(_("failed to iterate over '%s'"), src->buf);
 473         }
 474
 475         strbuf_release(&realpath);
 476 }
 477
 478 static void clone_local(const char *src_repo, const char *dest_repo)
 479 {
 480         if (option_shared) {
 481                 struct strbuf alt = STRBUF_INIT;
 482                 get_common_dir(&alt, src_repo);
 483                 strbuf_addstr(&alt, "/objects");
 484                 add_to_alternates_file(alt.buf);
 485                 strbuf_release(&alt);
 486         } else {
 487                 struct strbuf src = STRBUF_INIT;
 488                 struct strbuf dest = STRBUF_INIT;
 489                 get_common_dir(&src, src_repo);
 490                 get_common_dir(&dest, dest_repo);
 491                 strbuf_addstr(&src, "/objects");
 492                 strbuf_addstr(&dest, "/objects");
 493                 copy_or_link_directory(&src, &dest, src_repo);
 494                 strbuf_release(&src);
 495                 strbuf_release(&dest);
 496         }
 497
 498         if (0 <= option_verbosity)
 499                 fprintf(stderr, _("done.\n"));
 500 }
 501
 502 static const char *junk_work_tree;
 503 static int junk_work_tree_flags;
 504 static const char *junk_git_dir;
 505 static int junk_git_dir_flags;
 506 static enum {
 507         JUNK_LEAVE_NONE,
 508         JUNK_LEAVE_REPO,
 509         JUNK_LEAVE_ALL
 510 } junk_mode = JUNK_LEAVE_NONE;
 511
 512 static const char junk_leave_repo_msg[] =
 513 N_("Clone succeeded, but checkout failed.\n"
 514    "You can inspect what was checked out with 'git status'\n"
 515    "and retry with 'git restore --source=HEAD :/'\n");
 516
 517 static void remove_junk(void)
 518 {
 519         struct strbuf sb = STRBUF_INIT;
 520
 521         switch (junk_mode) {
 522         case JUNK_LEAVE_REPO:
 523                 warning("%s", _(junk_leave_repo_msg));
 524                 /* fall-through */
 525         case JUNK_LEAVE_ALL:
 526                 return;
 527         default:
 528                 /* proceed to removal */
 529                 break;
 530         }
 531
 532         if (junk_git_dir) {
 533                 strbuf_addstr(&sb, junk_git_dir);
 534                 remove_dir_recursively(&sb, junk_git_dir_flags);
 535                 strbuf_reset(&sb);
 536         }
 537         if (junk_work_tree) {
 538                 strbuf_addstr(&sb, junk_work_tree);
 539                 remove_dir_recursively(&sb, junk_work_tree_flags);
 540         }
 541         strbuf_release(&sb);
 542 }
 543
 544 static void remove_junk_on_signal(int signo)
 545 {
 546         remove_junk();
 547         sigchain_pop(signo);
 548         raise(signo);
 549 }
 550
 551 static struct ref *find_remote_branch(const struct ref *refs, const char *branch)
 552 {
 553         struct ref *ref;
 554         struct strbuf head = STRBUF_INIT;
 555         strbuf_addstr(&head, "refs/heads/");
 556         strbuf_addstr(&head, branch);
 557         ref = find_ref_by_name(refs, head.buf);
 558         strbuf_release(&head);
 559
 560         if (ref)
 561                 return ref;
 562
 563         strbuf_addstr(&head, "refs/tags/");
 564         strbuf_addstr(&head, branch);
 565         ref = find_ref_by_name(refs, head.buf);
 566         strbuf_release(&head);
 567
 568         return ref;
 569 }
 570
 571 static struct ref *wanted_peer_refs(const struct ref *refs,
 572                 struct refspec *refspec)
 573 {
 574         struct ref *head = copy_ref(find_ref_by_name(refs, "HEAD"));
 575         struct ref *local_refs = head;
 576         struct ref **tail = head ? &head->next : &local_refs;
 577
 578         if (option_single_branch) {
 579                 struct ref *remote_head = NULL;
 580
 581                 if (!option_branch)
 582                         remote_head = guess_remote_head(head, refs, 0);
 583                 else {
 584                         local_refs = NULL;
 585                         tail = &local_refs;
 586                         remote_head = copy_ref(find_remote_branch(refs, option_branch));
 587                 }
 588
 589                 if (!remote_head && option_branch)
 590                         warning(_("Could not find remote branch %s to clone."),
 591                                 option_branch);
 592                 else {
 593                         int i;
 594                         for (i = 0; i < refspec->nr; i++)
 595                                 get_fetch_map(remote_head, &refspec->items[i],
 596                                               &tail, 0);
 597
 598                         /* if --branch=tag, pull the requested tag explicitly */
 599                         get_fetch_map(remote_head, tag_refspec, &tail, 0);
 600                 }
 601         } else {
 602                 int i;
 603                 for (i = 0; i < refspec->nr; i++)
 604                         get_fetch_map(refs, &refspec->items[i], &tail, 0);
 605         }
 606
 607         if (!option_mirror && !option_single_branch && !option_no_tags)
 608                 get_fetch_map(refs, tag_refspec, &tail, 0);
 609
 610         return local_refs;
 611 }
 612
 613 static void write_remote_refs(const struct ref *local_refs)
 614 {
 615         const struct ref *r;
 616
 617         struct ref_transaction *t;
 618         struct strbuf err = STRBUF_INIT;
 619
 620         t = ref_transaction_begin(&err);
 621         if (!t)
 622                 die("%s", err.buf);
 623
 624         for (r = local_refs; r; r = r->next) {
 625                 if (!r->peer_ref)
 626                         continue;
 627                 if (ref_transaction_create(t, r->peer_ref->name, &r->old_oid,
 628                                            0, NULL, &err))
 629                         die("%s", err.buf);
 630         }
 631
 632         if (initial_ref_transaction_commit(t, &err))
 633                 die("%s", err.buf);
 634
 635         strbuf_release(&err);
 636         ref_transaction_free(t);
 637 }
 638
 639 static void write_followtags(const struct ref *refs, const char *msg)
 640 {
 641         const struct ref *ref;
 642         for (ref = refs; ref; ref = ref->next) {
 643                 if (!starts_with(ref->name, "refs/tags/"))
 644                         continue;
 645                 if (ends_with(ref->name, "^{}"))
 646                         continue;
 647                 if (!has_object_file_with_flags(&ref->old_oid,
 648                                                 OBJECT_INFO_QUICK |
 649                                                 OBJECT_INFO_SKIP_FETCH_OBJECT))
 650                         continue;
 651                 update_ref(msg, ref->name, &ref->old_oid, NULL, 0,
 652                            UPDATE_REFS_DIE_ON_ERR);
 653         }
 654 }
 655
 656 static int iterate_ref_map(void *cb_data, struct object_id *oid)
 657 {
 658         struct ref **rm = cb_data;
 659         struct ref *ref = *rm;
 660
 661         /*
 662          * Skip anything missing a peer_ref, which we are not
 663          * actually going to write a ref for.
 664          */
 665         while (ref && !ref->peer_ref)
 666                 ref = ref->next;
 667         /* Returning -1 notes "end of list" to the caller. */
 668         if (!ref)
 669                 return -1;
 670
 671         oidcpy(oid, &ref->old_oid);
 672         *rm = ref->next;
 673         return 0;
 674 }
 675
 676 static void update_remote_refs(const struct ref *refs,
 677                                const struct ref *mapped_refs,
 678                                const struct ref *remote_head_points_at,
 679                                const char *branch_top,
 680                                const char *msg,
 681                                struct transport *transport,
 682                                int check_connectivity)
 683 {
 684         const struct ref *rm = mapped_refs;
 685
 686         if (check_connectivity) {
 687                 struct check_connected_options opt = CHECK_CONNECTED_INIT;
 688
 689                 opt.transport = transport;
 690                 opt.progress = transport->progress;
 691
 692                 if (check_connected(iterate_ref_map, &rm, &opt))
 693                         die(_("remote did not send all necessary objects"));
 694         }
 695
 696         if (refs) {
 697                 write_remote_refs(mapped_refs);
 698                 if (option_single_branch && !option_no_tags)
 699                         write_followtags(refs, msg);
 700         }
 701
 702         if (remote_head_points_at && !option_bare) {
 703                 struct strbuf head_ref = STRBUF_INIT;
 704                 strbuf_addstr(&head_ref, branch_top);
 705                 strbuf_addstr(&head_ref, "HEAD");
 706                 if (create_symref(head_ref.buf,
 707                                   remote_head_points_at->peer_ref->name,
 708                                   msg) < 0)
 709                         die(_("unable to update %s"), head_ref.buf);
 710                 strbuf_release(&head_ref);
 711         }
 712 }
 713
 714 static void update_head(const struct ref *our, const struct ref *remote,
 715                         const char *msg)
 716 {
 717         const char *head;
 718         if (our && skip_prefix(our->name, "refs/heads/", &head)) {
 719                 /* Local default branch link */
 720                 if (create_symref("HEAD", our->name, NULL) < 0)
 721                         die(_("unable to update HEAD"));
 722                 if (!option_bare) {
 723                         update_ref(msg, "HEAD", &our->old_oid, NULL, 0,
 724                                    UPDATE_REFS_DIE_ON_ERR);
 725                         install_branch_config(0, head, remote_name, our->name);
 726                 }
 727         } else if (our) {
 728                 struct commit *c = lookup_commit_reference(the_repository,
 729                                                            &our->old_oid);
 730                 /* --branch specifies a non-branch (i.e. tags), detach HEAD */
 731                 update_ref(msg, "HEAD", &c->object.oid, NULL, REF_NO_DEREF,
 732                            UPDATE_REFS_DIE_ON_ERR);
 733         } else if (remote) {
 734                 /*
 735                  * We know remote HEAD points to a non-branch, or
 736                  * HEAD points to a branch but we don't know which one.
 737                  * Detach HEAD in all these cases.
 738                  */
 739                 update_ref(msg, "HEAD", &remote->old_oid, NULL, REF_NO_DEREF,
 740                            UPDATE_REFS_DIE_ON_ERR);
 741         }
 742 }
 743
 744 static int git_sparse_checkout_init(const char *repo)
 745 {
 746         struct strvec argv = STRVEC_INIT;
 747         int result = 0;
 748         strvec_pushl(&argv, "-C", repo, "sparse-checkout", "init", NULL);
 749
 750         /*
 751          * We must apply the setting in the current process
 752          * for the later checkout to use the sparse-checkout file.
 753          */
 754         core_apply_sparse_checkout = 1;
 755
 756         if (run_command_v_opt(argv.v, RUN_GIT_CMD)) {
 757                 error(_("failed to initialize sparse-checkout"));
 758                 result = 1;
 759         }
 760
 761         strvec_clear(&argv);
 762         return result;
 763 }
 764
 765 static int checkout(int submodule_progress)
 766 {
 767         struct object_id oid;
 768         char *head;
 769         struct lock_file lock_file = LOCK_INIT;
 770         struct unpack_trees_options opts;
 771         struct tree *tree;
 772         struct tree_desc t;
 773         int err = 0;
 774
 775         if (option_no_checkout)
 776                 return 0;
 777
 778         head = resolve_refdup("HEAD", RESOLVE_REF_READING, &oid, NULL);
 779         if (!head) {
 780                 warning(_("remote HEAD refers to nonexistent ref, "
 781                           "unable to checkout.\n"));
 782                 return 0;
 783         }
 784         if (!strcmp(head, "HEAD")) {
 785                 if (advice_detached_head)
 786                         detach_advice(oid_to_hex(&oid));
 787                 FREE_AND_NULL(head);
 788         } else {
 789                 if (!starts_with(head, "refs/heads/"))
 790                         die(_("HEAD not found below refs/heads!"));
 791         }
 792
 793         /* We need to be in the new work tree for the checkout */
 794         setup_work_tree();
 795
 796         hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 797
 798         memset(&opts, 0, sizeof opts);
 799         opts.update = 1;
 800         opts.merge = 1;
 801         opts.clone = 1;
 802         opts.fn = oneway_merge;
 803         opts.verbose_update = (option_verbosity >= 0);
 804         opts.src_index = &the_index;
 805         opts.dst_index = &the_index;
 806         init_checkout_metadata(&opts.meta, head, &oid, NULL);
 807
 808         tree = parse_tree_indirect(&oid);
 809         parse_tree(tree);
 810         init_tree_desc(&t, tree->buffer, tree->size);
 811         if (unpack_trees(1, &t, &opts) < 0)
 812                 die(_("unable to checkout working tree"));
 813
 814         free(head);
 815
 816         if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 817                 die(_("unable to write new index file"));
 818
 819         err |= run_hook_le(NULL, "post-checkout", oid_to_hex(&null_oid),
 820                            oid_to_hex(&oid), "1", NULL);
 821
 822         if (!err && (option_recurse_submodules.nr > 0)) {
 823                 struct strvec args = STRVEC_INIT;
 824                 strvec_pushl(&args, "submodule", "update", "--require-init", "--recursive", NULL);
 825
 826                 if (option_shallow_submodules == 1)
 827                         strvec_push(&args, "--depth=1");
 828
 829                 if (max_jobs != -1)
 830                         strvec_pushf(&args, "--jobs=%d", max_jobs);
 831
 832                 if (submodule_progress)
 833                         strvec_push(&args, "--progress");
 834
 835                 if (option_verbosity < 0)
 836                         strvec_push(&args, "--quiet");
 837
 838                 if (option_remote_submodules) {
 839                         strvec_push(&args, "--remote");
 840                         strvec_push(&args, "--no-fetch");
 841                 }
 842
 843                 if (option_single_branch >= 0)
 844                         strvec_push(&args, option_single_branch ?
 845                                                "--single-branch" :
 846                                                "--no-single-branch");
 847
 848                 err = run_command_v_opt(args.v, RUN_GIT_CMD);
 849                 strvec_clear(&args);
 850         }
 851
 852         return err;
 853 }
 854
 855 static int git_clone_config(const char *k, const char *v, void *cb)
 856 {
 857         if (!strcmp(k, "clone.defaultremotename")) {
 858                 free(remote_name);
 859                 remote_name = xstrdup(v);
 860         }
 861         return git_default_config(k, v, cb);
 862 }
 863
 864 static int write_one_config(const char *key, const char *value, void *data)
 865 {
 866         /*
 867          * give git_clone_config a chance to write config values back to the
 868          * environment, since git_config_set_multivar_gently only deals with
 869          * config-file writes
 870          */
 871         int apply_failed = git_clone_config(key, value, data);
 872         if (apply_failed)
 873                 return apply_failed;
 874
 875         return git_config_set_multivar_gently(key,
 876                                               value ? value : "true",
 877                                               CONFIG_REGEX_NONE, 0);
 878 }
 879
 880 static void write_config(struct string_list *config)
 881 {
 882         int i;
 883
 884         for (i = 0; i < config->nr; i++) {
 885                 if (git_config_parse_parameter(config->items[i].string,
 886                                                write_one_config, NULL) < 0)
 887                         die(_("unable to write parameters to config file"));
 888         }
 889 }
 890
 891 static void write_refspec_config(const char *src_ref_prefix,
 892                 const struct ref *our_head_points_at,
 893                 const struct ref *remote_head_points_at,
 894                 struct strbuf *branch_top)
 895 {
 896         struct strbuf key = STRBUF_INIT;
 897         struct strbuf value = STRBUF_INIT;
 898
 899         if (option_mirror || !option_bare) {
 900                 if (option_single_branch && !option_mirror) {
 901                         if (option_branch) {
 902                                 if (starts_with(our_head_points_at->name, "refs/tags/"))
 903                                         strbuf_addf(&value, "+%s:%s", our_head_points_at->name,
 904                                                 our_head_points_at->name);
 905                                 else
 906                                         strbuf_addf(&value, "+%s:%s%s", our_head_points_at->name,
 907                                                 branch_top->buf, option_branch);
 908                         } else if (remote_head_points_at) {
 909                                 const char *head = remote_head_points_at->name;
 910                                 if (!skip_prefix(head, "refs/heads/", &head))
 911                                         BUG("remote HEAD points at non-head?");
 912
 913                                 strbuf_addf(&value, "+%s:%s%s", remote_head_points_at->name,
 914                                                 branch_top->buf, head);
 915                         }
 916                         /*
 917                          * otherwise, the next "git fetch" will
 918                          * simply fetch from HEAD without updating
 919                          * any remote-tracking branch, which is what
 920                          * we want.
 921                          */
 922                 } else {
 923                         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top->buf);
 924                 }
 925                 /* Configure the remote */
 926                 if (value.len) {
 927                         strbuf_addf(&key, "remote.%s.fetch", remote_name);
 928                         git_config_set_multivar(key.buf, value.buf, "^$", 0);
 929                         strbuf_reset(&key);
 930
 931                         if (option_mirror) {
 932                                 strbuf_addf(&key, "remote.%s.mirror", remote_name);
 933                                 git_config_set(key.buf, "true");
 934                                 strbuf_reset(&key);
 935                         }
 936                 }
 937         }
 938
 939         strbuf_release(&key);
 940         strbuf_release(&value);
 941 }
 942
 943 static void dissociate_from_references(void)
 944 {
 945         static const char* argv[] = { "repack", "-a", "-d", NULL };
 946         char *alternates = git_pathdup("objects/info/alternates");
 947
 948         if (!access(alternates, F_OK)) {
 949                 if (run_command_v_opt(argv, RUN_GIT_CMD|RUN_COMMAND_NO_STDIN))
 950                         die(_("cannot repack to clean up"));
 951                 if (unlink(alternates) && errno != ENOENT)
 952                         die_errno(_("cannot unlink temporary alternates file"));
 953         }
 954         free(alternates);
 955 }
 956
 957 static int path_exists(const char *path)
 958 {
 959         struct stat sb;
 960         return !stat(path, &sb);
 961 }
 962
 963 int cmd_clone(int argc, const char **argv, const char *prefix)
 964 {
 965         int is_bundle = 0, is_local;
 966         const char *repo_name, *repo, *work_tree, *git_dir;
 967         char *path, *dir, *display_repo = NULL;
 968         int dest_exists, real_dest_exists = 0;
 969         const struct ref *refs, *remote_head;
 970         const struct ref *remote_head_points_at;
 971         const struct ref *our_head_points_at;
 972         struct ref *mapped_refs;
 973         const struct ref *ref;
 974         struct strbuf key = STRBUF_INIT;
 975         struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
 976         struct transport *transport = NULL;
 977         const char *src_ref_prefix = "refs/heads/";
 978         struct remote *remote;
 979         int err = 0, complete_refs_before_fetch = 1;
 980         int submodule_progress;
 981
 982         struct strvec ref_prefixes = STRVEC_INIT;
 983
 984         packet_trace_identity("clone");
 985
 986         git_config(git_clone_config, NULL);
 987
 988         argc = parse_options(argc, argv, prefix, builtin_clone_options,
 989                              builtin_clone_usage, 0);
 990
 991         if (argc > 2)
 992                 usage_msg_opt(_("Too many arguments."),
 993                         builtin_clone_usage, builtin_clone_options);
 994
 995         if (argc == 0)
 996                 usage_msg_opt(_("You must specify a repository to clone."),
 997                         builtin_clone_usage, builtin_clone_options);
 998
 999         if (option_depth || option_since || option_not.nr)
1000                 deepen = 1;
1001         if (option_single_branch == -1)
1002                 option_single_branch = deepen ? 1 : 0;
1003
1004         if (option_mirror)
1005                 option_bare = 1;
1006
1007         if (option_bare) {
1008                 if (option_origin)
1009                         die(_("--bare and --origin %s options are incompatible."),
1010                             option_origin);
1011                 if (real_git_dir)
1012                         die(_("--bare and --separate-git-dir are incompatible."));
1013                 option_no_checkout = 1;
1014         }
1015
1016         repo_name = argv[0];
1017
1018         path = get_repo_path(repo_name, &is_bundle);
1019         if (path)
1020                 repo = absolute_pathdup(repo_name);
1021         else if (strchr(repo_name, ':')) {
1022                 repo = repo_name;
1023                 display_repo = transport_anonymize_url(repo);
1024         } else
1025                 die(_("repository '%s' does not exist"), repo_name);
1026
1027         /* no need to be strict, transport_set_option() will validate it again */
1028         if (option_depth && atoi(option_depth) < 1)
1029                 die(_("depth %s is not a positive number"), option_depth);
1030
1031         if (argc == 2)
1032                 dir = xstrdup(argv[1]);
1033         else
1034                 dir = guess_dir_name(repo_name, is_bundle, option_bare);
1035         strip_trailing_slashes(dir);
1036
1037         dest_exists = path_exists(dir);
1038         if (dest_exists && !is_empty_dir(dir))
1039                 die(_("destination path '%s' already exists and is not "
1040                         "an empty directory."), dir);
1041
1042         if (real_git_dir) {
1043                 real_dest_exists = path_exists(real_git_dir);
1044                 if (real_dest_exists && !is_empty_dir(real_git_dir))
1045                         die(_("repository path '%s' already exists and is not "
1046                                 "an empty directory."), real_git_dir);
1047         }
1048
1049
1050         strbuf_addf(&reflog_msg, "clone: from %s",
1051                     display_repo ? display_repo : repo);
1052         free(display_repo);
1053
1054         if (option_bare)
1055                 work_tree = NULL;
1056         else {
1057                 work_tree = getenv("GIT_WORK_TREE");
1058                 if (work_tree && path_exists(work_tree))
1059                         die(_("working tree '%s' already exists."), work_tree);
1060         }
1061
1062         if (option_bare || work_tree)
1063                 git_dir = xstrdup(dir);
1064         else {
1065                 work_tree = dir;
1066                 git_dir = mkpathdup("%s/.git", dir);
1067         }
1068
1069         atexit(remove_junk);
1070         sigchain_push_common(remove_junk_on_signal);
1071
1072         if (!option_bare) {
1073                 if (safe_create_leading_directories_const(work_tree) < 0)
1074                         die_errno(_("could not create leading directories of '%s'"),
1075                                   work_tree);
1076                 if (dest_exists)
1077                         junk_work_tree_flags |= REMOVE_DIR_KEEP_TOPLEVEL;
1078                 else if (mkdir(work_tree, 0777))
1079                         die_errno(_("could not create work tree dir '%s'"),
1080                                   work_tree);
1081                 junk_work_tree = work_tree;
1082                 set_git_work_tree(work_tree);
1083         }
1084
1085         if (real_git_dir) {
1086                 if (real_dest_exists)
1087                         junk_git_dir_flags |= REMOVE_DIR_KEEP_TOPLEVEL;
1088                 junk_git_dir = real_git_dir;
1089         } else {
1090                 if (dest_exists)
1091                         junk_git_dir_flags |= REMOVE_DIR_KEEP_TOPLEVEL;
1092                 junk_git_dir = git_dir;
1093         }
1094         if (safe_create_leading_directories_const(git_dir) < 0)
1095                 die(_("could not create leading directories of '%s'"), git_dir);
1096
1097         if (0 <= option_verbosity) {
1098                 if (option_bare)
1099                         fprintf(stderr, _("Cloning into bare repository '%s'...\n"), dir);
1100                 else
1101                         fprintf(stderr, _("Cloning into '%s'...\n"), dir);
1102         }
1103
1104         if (option_recurse_submodules.nr > 0) {
1105                 struct string_list_item *item;
1106                 struct strbuf sb = STRBUF_INIT;
1107
1108                 /* remove duplicates */
1109                 string_list_sort(&option_recurse_submodules);
1110                 string_list_remove_duplicates(&option_recurse_submodules, 0);
1111
1112                 /*
1113                  * NEEDSWORK: In a multi-working-tree world, this needs to be
1114                  * set in the per-worktree config.
1115                  */
1116                 for_each_string_list_item(item, &option_recurse_submodules) {
1117                         strbuf_addf(&sb, "submodule.active=%s",
1118                                     item->string);
1119                         string_list_append(&option_config,
1120                                            strbuf_detach(&sb, NULL));
1121                 }
1122
1123                 if (option_required_reference.nr &&
1124                     option_optional_reference.nr)
1125                         die(_("clone --recursive is not compatible with "
1126                               "both --reference and --reference-if-able"));
1127                 else if (option_required_reference.nr) {
1128                         string_list_append(&option_config,
1129                                 "submodule.alternateLocation=superproject");
1130                         string_list_append(&option_config,
1131                                 "submodule.alternateErrorStrategy=die");
1132                 } else if (option_optional_reference.nr) {
1133                         string_list_append(&option_config,
1134                                 "submodule.alternateLocation=superproject");
1135                         string_list_append(&option_config,
1136                                 "submodule.alternateErrorStrategy=info");
1137                 }
1138         }
1139
1140         init_db(git_dir, real_git_dir, option_template, GIT_HASH_UNKNOWN, NULL,
1141                 INIT_DB_QUIET);
1142
1143         if (real_git_dir)
1144                 git_dir = real_git_dir;
1145
1146         /*
1147          * additional config can be injected with -c, make sure it's included
1148          * after init_db, which clears the entire config environment.
1149          */
1150         write_config(&option_config);
1151
1152         /*
1153          * re-read config after init_db and write_config to pick up any config
1154          * injected by --template and --config, respectively.
1155          */
1156         git_config(git_clone_config, NULL);
1157
1158         /*
1159          * apply the remote name provided by --origin only after this second
1160          * call to git_config, to ensure it overrides all config-based values.
1161          */
1162         if (option_origin != NULL)
1163                 remote_name = xstrdup(option_origin);
1164
1165         if (remote_name == NULL)
1166                 remote_name = xstrdup("origin");
1167
1168         if (!valid_remote_name(remote_name))
1169                 die(_("'%s' is not a valid remote name"), remote_name);
1170
1171         if (option_bare) {
1172                 if (option_mirror)
1173                         src_ref_prefix = "refs/";
1174                 strbuf_addstr(&branch_top, src_ref_prefix);
1175
1176                 git_config_set("core.bare", "true");
1177         } else {
1178                 strbuf_addf(&branch_top, "refs/remotes/%s/", remote_name);
1179         }
1180
1181         strbuf_addf(&key, "remote.%s.url", remote_name);
1182         git_config_set(key.buf, repo);
1183         strbuf_reset(&key);
1184
1185         if (option_no_tags) {
1186                 strbuf_addf(&key, "remote.%s.tagOpt", remote_name);
1187                 git_config_set(key.buf, "--no-tags");
1188                 strbuf_reset(&key);
1189         }
1190
1191         if (option_required_reference.nr || option_optional_reference.nr)
1192                 setup_reference();
1193
1194         if (option_sparse_checkout && git_sparse_checkout_init(dir))
1195                 return 1;
1196
1197         remote = remote_get(remote_name);
1198
1199         refspec_appendf(&remote->fetch, "+%s*:%s*", src_ref_prefix,
1200                         branch_top.buf);
1201
1202         transport = transport_get(remote, remote->url[0]);
1203         transport_set_verbosity(transport, option_verbosity, option_progress);
1204         transport->family = family;
1205
1206         path = get_repo_path(remote->url[0], &is_bundle);
1207         is_local = option_local != 0 && path && !is_bundle;
1208         if (is_local) {
1209                 if (option_depth)
1210                         warning(_("--depth is ignored in local clones; use file:// instead."));
1211                 if (option_since)
1212                         warning(_("--shallow-since is ignored in local clones; use file:// instead."));
1213                 if (option_not.nr)
1214                         warning(_("--shallow-exclude is ignored in local clones; use file:// instead."));
1215                 if (filter_options.choice)
1216                         warning(_("--filter is ignored in local clones; use file:// instead."));
1217                 if (!access(mkpath("%s/shallow", path), F_OK)) {
1218                         if (option_local > 0)
1219                                 warning(_("source repository is shallow, ignoring --local"));
1220                         is_local = 0;
1221                 }
1222         }
1223         if (option_local > 0 && !is_local)
1224                 warning(_("--local is ignored"));
1225         transport->cloning = 1;
1226
1227         transport_set_option(transport, TRANS_OPT_KEEP, "yes");
1228
1229         if (option_depth)
1230                 transport_set_option(transport, TRANS_OPT_DEPTH,
1231                                      option_depth);
1232         if (option_since)
1233                 transport_set_option(transport, TRANS_OPT_DEEPEN_SINCE,
1234                                      option_since);
1235         if (option_not.nr)
1236                 transport_set_option(transport, TRANS_OPT_DEEPEN_NOT,
1237                                      (const char *)&option_not);
1238         if (option_single_branch)
1239                 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
1240
1241         if (option_upload_pack)
1242                 transport_set_option(transport, TRANS_OPT_UPLOADPACK,
1243                                      option_upload_pack);
1244
1245         if (server_options.nr)
1246                 transport->server_options = &server_options;
1247
1248         if (filter_options.choice) {
1249                 const char *spec =
1250                         expand_list_objects_filter_spec(&filter_options);
1251                 transport_set_option(transport, TRANS_OPT_LIST_OBJECTS_FILTER,
1252                                      spec);
1253                 transport_set_option(transport, TRANS_OPT_FROM_PROMISOR, "1");
1254         }
1255
1256         if (transport->smart_options && !deepen && !filter_options.choice)
1257                 transport->smart_options->check_self_contained_and_connected = 1;
1258
1259
1260         strvec_push(&ref_prefixes, "HEAD");
1261         refspec_ref_prefixes(&remote->fetch, &ref_prefixes);
1262         if (option_branch)
1263                 expand_ref_prefix(&ref_prefixes, option_branch);
1264         if (!option_no_tags)
1265                 strvec_push(&ref_prefixes, "refs/tags/");
1266
1267         refs = transport_get_remote_refs(transport, &ref_prefixes);
1268
1269         if (refs) {
1270                 int hash_algo = hash_algo_by_ptr(transport_get_hash_algo(transport));
1271
1272                 /*
1273                  * Now that we know what algorithm the remote side is using,
1274                  * let's set ours to the same thing.
1275                  */
1276                 initialize_repository_version(hash_algo, 1);
1277                 repo_set_hash_algo(the_repository, hash_algo);
1278
1279                 mapped_refs = wanted_peer_refs(refs, &remote->fetch);
1280                 /*
1281                  * transport_get_remote_refs() may return refs with null sha-1
1282                  * in mapped_refs (see struct transport->get_refs_list
1283                  * comment). In that case we need fetch it early because
1284                  * remote_head code below relies on it.
1285                  *
1286                  * for normal clones, transport_get_remote_refs() should
1287                  * return reliable ref set, we can delay cloning until after
1288                  * remote HEAD check.
1289                  */
1290                 for (ref = refs; ref; ref = ref->next)
1291                         if (is_null_oid(&ref->old_oid)) {
1292                                 complete_refs_before_fetch = 0;
1293                                 break;
1294                         }
1295
1296                 if (!is_local && !complete_refs_before_fetch) {
1297                         err = transport_fetch_refs(transport, mapped_refs);
1298                         if (err)
1299                                 goto cleanup;
1300                 }
1301
1302                 remote_head = find_ref_by_name(refs, "HEAD");
1303                 remote_head_points_at =
1304                         guess_remote_head(remote_head, mapped_refs, 0);
1305
1306                 if (option_branch) {
1307                         our_head_points_at =
1308                                 find_remote_branch(mapped_refs, option_branch);
1309
1310                         if (!our_head_points_at)
1311                                 die(_("Remote branch %s not found in upstream %s"),
1312                                     option_branch, remote_name);
1313                 }
1314                 else
1315                         our_head_points_at = remote_head_points_at;
1316         }
1317         else {
1318                 if (option_branch)
1319                         die(_("Remote branch %s not found in upstream %s"),
1320                                         option_branch, remote_name);
1321
1322                 warning(_("You appear to have cloned an empty repository."));
1323                 mapped_refs = NULL;
1324                 our_head_points_at = NULL;
1325                 remote_head_points_at = NULL;
1326                 remote_head = NULL;
1327                 option_no_checkout = 1;
1328                 if (!option_bare) {
1329                         const char *branch = git_default_branch_name(0);
1330                         char *ref = xstrfmt("refs/heads/%s", branch);
1331
1332                         install_branch_config(0, branch, remote_name, ref);
1333                         free(ref);
1334                 }
1335         }
1336
1337         write_refspec_config(src_ref_prefix, our_head_points_at,
1338                         remote_head_points_at, &branch_top);
1339
1340         if (filter_options.choice)
1341                 partial_clone_register(remote_name, &filter_options);
1342
1343         if (is_local)
1344                 clone_local(path, git_dir);
1345         else if (refs && complete_refs_before_fetch) {
1346                 err = transport_fetch_refs(transport, mapped_refs);
1347                 if (err)
1348                         goto cleanup;
1349         }
1350
1351         update_remote_refs(refs, mapped_refs, remote_head_points_at,
1352                            branch_top.buf, reflog_msg.buf, transport,
1353                            !is_local);
1354
1355         update_head(our_head_points_at, remote_head, reflog_msg.buf);
1356
1357         /*
1358          * We want to show progress for recursive submodule clones iff
1359          * we did so for the main clone. But only the transport knows
1360          * the final decision for this flag, so we need to rescue the value
1361          * before we free the transport.
1362          */
1363         submodule_progress = transport->progress;
1364
1365         transport_unlock_pack(transport);
1366         transport_disconnect(transport);
1367
1368         if (option_dissociate) {
1369                 close_object_store(the_repository->objects);
1370                 dissociate_from_references();
1371         }
1372
1373         junk_mode = JUNK_LEAVE_REPO;
1374         err = checkout(submodule_progress);
1375
1376 cleanup:
1377         free(remote_name);
1378         strbuf_release(&reflog_msg);
1379         strbuf_release(&branch_top);
1380         strbuf_release(&key);
1381         junk_mode = JUNK_LEAVE_ALL;
1382
1383         strvec_clear(&ref_prefixes);
1384         return err;
1385 }