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 "lockfile.h"
  13 #include "parse-options.h"
  14 #include "fetch-pack.h"
  15 #include "refs.h"
  16 #include "tree.h"
  17 #include "tree-walk.h"
  18 #include "unpack-trees.h"
  19 #include "transport.h"
  20 #include "strbuf.h"
  21 #include "dir.h"
  22 #include "sigchain.h"
  23 #include "branch.h"
  24 #include "remote.h"
  25 #include "run-command.h"
  26 #include "connected.h"
  27
  28 /*
  29  * Overall FIXMEs:
  30  *  - respect DB_ENVIRONMENT for .git/objects.
  31  *
  32  * Implementation notes:
  33  *  - dropping use-separate-remote and no-separate-remote compatibility
  34  *
  35  */
  36 static const char * const builtin_clone_usage[] = {
  37         N_("git clone [<options>] [--] <repo> [<dir>]"),
  38         NULL
  39 };
  40
  41 static int option_no_checkout, option_bare, option_mirror, option_single_branch = -1;
  42 static int option_local = -1, option_no_hardlinks, option_shared, option_recursive;
  43 static int option_shallow_submodules;
  44 static char *option_template, *option_depth;
  45 static char *option_origin = NULL;
  46 static char *option_branch = NULL;
  47 static const char *real_git_dir;
  48 static char *option_upload_pack = "git-upload-pack";
  49 static int option_verbosity;
  50 static int option_progress = -1;
  51 static enum transport_family family;
  52 static struct string_list option_config = STRING_LIST_INIT_NODUP;
  53 static struct string_list option_reference = STRING_LIST_INIT_NODUP;
  54 static int option_dissociate;
  55 static int max_jobs = -1;
  56
  57 static struct option builtin_clone_options[] = {
  58         OPT__VERBOSITY(&option_verbosity),
  59         OPT_BOOL(0, "progress", &option_progress,
  60                  N_("force progress reporting")),
  61         OPT_BOOL('n', "no-checkout", &option_no_checkout,
  62                  N_("don't create a checkout")),
  63         OPT_BOOL(0, "bare", &option_bare, N_("create a bare repository")),
  64         OPT_HIDDEN_BOOL(0, "naked", &option_bare,
  65                         N_("create a bare repository")),
  66         OPT_BOOL(0, "mirror", &option_mirror,
  67                  N_("create a mirror repository (implies bare)")),
  68         OPT_BOOL('l', "local", &option_local,
  69                 N_("to clone from a local repository")),
  70         OPT_BOOL(0, "no-hardlinks", &option_no_hardlinks,
  71                     N_("don't use local hardlinks, always copy")),
  72         OPT_BOOL('s', "shared", &option_shared,
  73                     N_("setup as shared repository")),
  74         OPT_BOOL(0, "recursive", &option_recursive,
  75                     N_("initialize submodules in the clone")),
  76         OPT_BOOL(0, "recurse-submodules", &option_recursive,
  77                     N_("initialize submodules in the clone")),
  78         OPT_INTEGER('j', "jobs", &max_jobs,
  79                     N_("number of submodules cloned in parallel")),
  80         OPT_STRING(0, "template", &option_template, N_("template-directory"),
  81                    N_("directory from which templates will be used")),
  82         OPT_STRING_LIST(0, "reference", &option_reference, N_("repo"),
  83                         N_("reference repository")),
  84         OPT_BOOL(0, "dissociate", &option_dissociate,
  85                  N_("use --reference only while cloning")),
  86         OPT_STRING('o', "origin", &option_origin, N_("name"),
  87                    N_("use <name> instead of 'origin' to track upstream")),
  88         OPT_STRING('b', "branch", &option_branch, N_("branch"),
  89                    N_("checkout <branch> instead of the remote's HEAD")),
  90         OPT_STRING('u', "upload-pack", &option_upload_pack, N_("path"),
  91                    N_("path to git-upload-pack on the remote")),
  92         OPT_STRING(0, "depth", &option_depth, N_("depth"),
  93                     N_("create a shallow clone of that depth")),
  94         OPT_BOOL(0, "single-branch", &option_single_branch,
  95                     N_("clone only one branch, HEAD or --branch")),
  96         OPT_BOOL(0, "shallow-submodules", &option_shallow_submodules,
  97                     N_("any cloned submodules will be shallow")),
  98         OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
  99                    N_("separate git dir from working tree")),
 100         OPT_STRING_LIST('c', "config", &option_config, N_("key=value"),
 101                         N_("set config inside the new repository")),
 102         OPT_SET_INT('4', "ipv4", &family, N_("use IPv4 addresses only"),
 103                         TRANSPORT_FAMILY_IPV4),
 104         OPT_SET_INT('6', "ipv6", &family, N_("use IPv6 addresses only"),
 105                         TRANSPORT_FAMILY_IPV6),
 106         OPT_END()
 107 };
 108
 109 static const char *get_repo_path_1(struct strbuf *path, int *is_bundle)
 110 {
 111         static char *suffix[] = { "/.git", "", ".git/.git", ".git" };
 112         static char *bundle_suffix[] = { ".bundle", "" };
 113         size_t baselen = path->len;
 114         struct stat st;
 115         int i;
 116
 117         for (i = 0; i < ARRAY_SIZE(suffix); i++) {
 118                 strbuf_setlen(path, baselen);
 119                 strbuf_addstr(path, suffix[i]);
 120                 if (stat(path->buf, &st))
 121                         continue;
 122                 if (S_ISDIR(st.st_mode) && is_git_directory(path->buf)) {
 123                         *is_bundle = 0;
 124                         return path->buf;
 125                 } else if (S_ISREG(st.st_mode) && st.st_size > 8) {
 126                         /* Is it a "gitfile"? */
 127                         char signature[8];
 128                         const char *dst;
 129                         int len, fd = open(path->buf, O_RDONLY);
 130                         if (fd < 0)
 131                                 continue;
 132                         len = read_in_full(fd, signature, 8);
 133                         close(fd);
 134                         if (len != 8 || strncmp(signature, "gitdir: ", 8))
 135                                 continue;
 136                         dst = read_gitfile(path->buf);
 137                         if (dst) {
 138                                 *is_bundle = 0;
 139                                 return dst;
 140                         }
 141                 }
 142         }
 143
 144         for (i = 0; i < ARRAY_SIZE(bundle_suffix); i++) {
 145                 strbuf_setlen(path, baselen);
 146                 strbuf_addstr(path, bundle_suffix[i]);
 147                 if (!stat(path->buf, &st) && S_ISREG(st.st_mode)) {
 148                         *is_bundle = 1;
 149                         return path->buf;
 150                 }
 151         }
 152
 153         return NULL;
 154 }
 155
 156 static char *get_repo_path(const char *repo, int *is_bundle)
 157 {
 158         struct strbuf path = STRBUF_INIT;
 159         const char *raw;
 160         char *canon;
 161
 162         strbuf_addstr(&path, repo);
 163         raw = get_repo_path_1(&path, is_bundle);
 164         canon = raw ? xstrdup(absolute_path(raw)) : NULL;
 165         strbuf_release(&path);
 166         return canon;
 167 }
 168
 169 static char *guess_dir_name(const char *repo, int is_bundle, int is_bare)
 170 {
 171         const char *end = repo + strlen(repo), *start, *ptr;
 172         size_t len;
 173         char *dir;
 174
 175         /*
 176          * Skip scheme.
 177          */
 178         start = strstr(repo, "://");
 179         if (start == NULL)
 180                 start = repo;
 181         else
 182                 start += 3;
 183
 184         /*
 185          * Skip authentication data. The stripping does happen
 186          * greedily, such that we strip up to the last '@' inside
 187          * the host part.
 188          */
 189         for (ptr = start; ptr < end && !is_dir_sep(*ptr); ptr++) {
 190                 if (*ptr == '@')
 191                         start = ptr + 1;
 192         }
 193
 194         /*
 195          * Strip trailing spaces, slashes and /.git
 196          */
 197         while (start < end && (is_dir_sep(end[-1]) || isspace(end[-1])))
 198                 end--;
 199         if (end - start > 5 && is_dir_sep(end[-5]) &&
 200             !strncmp(end - 4, ".git", 4)) {
 201                 end -= 5;
 202                 while (start < end && is_dir_sep(end[-1]))
 203                         end--;
 204         }
 205
 206         /*
 207          * Strip trailing port number if we've got only a
 208          * hostname (that is, there is no dir separator but a
 209          * colon). This check is required such that we do not
 210          * strip URI's like '/foo/bar:2222.git', which should
 211          * result in a dir '2222' being guessed due to backwards
 212          * compatibility.
 213          */
 214         if (memchr(start, '/', end - start) == NULL
 215             && memchr(start, ':', end - start) != NULL) {
 216                 ptr = end;
 217                 while (start < ptr && isdigit(ptr[-1]) && ptr[-1] != ':')
 218                         ptr--;
 219                 if (start < ptr && ptr[-1] == ':')
 220                         end = ptr - 1;
 221         }
 222
 223         /*
 224          * Find last component. To remain backwards compatible we
 225          * also regard colons as path separators, such that
 226          * cloning a repository 'foo:bar.git' would result in a
 227          * directory 'bar' being guessed.
 228          */
 229         ptr = end;
 230         while (start < ptr && !is_dir_sep(ptr[-1]) && ptr[-1] != ':')
 231                 ptr--;
 232         start = ptr;
 233
 234         /*
 235          * Strip .{bundle,git}.
 236          */
 237         len = end - start;
 238         strip_suffix_mem(start, &len, is_bundle ? ".bundle" : ".git");
 239
 240         if (!len || (len == 1 && *start == '/'))
 241                 die(_("No directory name could be guessed.\n"
 242                       "Please specify a directory on the command line"));
 243
 244         if (is_bare)
 245                 dir = xstrfmt("%.*s.git", (int)len, start);
 246         else
 247                 dir = xstrndup(start, len);
 248         /*
 249          * Replace sequences of 'control' characters and whitespace
 250          * with one ascii space, remove leading and trailing spaces.
 251          */
 252         if (*dir) {
 253                 char *out = dir;
 254                 int prev_space = 1 /* strip leading whitespace */;
 255                 for (end = dir; *end; ++end) {
 256                         char ch = *end;
 257                         if ((unsigned char)ch < '\x20')
 258                                 ch = '\x20';
 259                         if (isspace(ch)) {
 260                                 if (prev_space)
 261                                         continue;
 262                                 prev_space = 1;
 263                         } else
 264                                 prev_space = 0;
 265                         *out++ = ch;
 266                 }
 267                 *out = '\0';
 268                 if (out > dir && prev_space)
 269                         out[-1] = '\0';
 270         }
 271         return dir;
 272 }
 273
 274 static void strip_trailing_slashes(char *dir)
 275 {
 276         char *end = dir + strlen(dir);
 277
 278         while (dir < end - 1 && is_dir_sep(end[-1]))
 279                 end--;
 280         *end = '\0';
 281 }
 282
 283 static int add_one_reference(struct string_list_item *item, void *cb_data)
 284 {
 285         char *ref_git;
 286         const char *repo;
 287         struct strbuf alternate = STRBUF_INIT;
 288
 289         /* Beware: read_gitfile(), real_path() and mkpath() return static buffer */
 290         ref_git = xstrdup(real_path(item->string));
 291
 292         repo = read_gitfile(ref_git);
 293         if (!repo)
 294                 repo = read_gitfile(mkpath("%s/.git", ref_git));
 295         if (repo) {
 296                 free(ref_git);
 297                 ref_git = xstrdup(repo);
 298         }
 299
 300         if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
 301                 char *ref_git_git = mkpathdup("%s/.git", ref_git);
 302                 free(ref_git);
 303                 ref_git = ref_git_git;
 304         } else if (!is_directory(mkpath("%s/objects", ref_git))) {
 305                 struct strbuf sb = STRBUF_INIT;
 306                 if (get_common_dir(&sb, ref_git))
 307                         die(_("reference repository '%s' as a linked checkout is not supported yet."),
 308                             item->string);
 309                 die(_("reference repository '%s' is not a local repository."),
 310                     item->string);
 311         }
 312
 313         if (!access(mkpath("%s/shallow", ref_git), F_OK))
 314                 die(_("reference repository '%s' is shallow"), item->string);
 315
 316         if (!access(mkpath("%s/info/grafts", ref_git), F_OK))
 317                 die(_("reference repository '%s' is grafted"), item->string);
 318
 319         strbuf_addf(&alternate, "%s/objects", ref_git);
 320         add_to_alternates_file(alternate.buf);
 321         strbuf_release(&alternate);
 322         free(ref_git);
 323         return 0;
 324 }
 325
 326 static void setup_reference(void)
 327 {
 328         for_each_string_list(&option_reference, add_one_reference, NULL);
 329 }
 330
 331 static void copy_alternates(struct strbuf *src, struct strbuf *dst,
 332                             const char *src_repo)
 333 {
 334         /*
 335          * Read from the source objects/info/alternates file
 336          * and copy the entries to corresponding file in the
 337          * destination repository with add_to_alternates_file().
 338          * Both src and dst have "$path/objects/info/alternates".
 339          *
 340          * Instead of copying bit-for-bit from the original,
 341          * we need to append to existing one so that the already
 342          * created entry via "clone -s" is not lost, and also
 343          * to turn entries with paths relative to the original
 344          * absolute, so that they can be used in the new repository.
 345          */
 346         FILE *in = fopen(src->buf, "r");
 347         struct strbuf line = STRBUF_INIT;
 348
 349         while (strbuf_getline(&line, in) != EOF) {
 350                 char *abs_path;
 351                 if (!line.len || line.buf[0] == '#')
 352                         continue;
 353                 if (is_absolute_path(line.buf)) {
 354                         add_to_alternates_file(line.buf);
 355                         continue;
 356                 }
 357                 abs_path = mkpathdup("%s/objects/%s", src_repo, line.buf);
 358                 if (!normalize_path_copy(abs_path, abs_path))
 359                         add_to_alternates_file(abs_path);
 360                 else
 361                         warning("skipping invalid relative alternate: %s/%s",
 362                                 src_repo, line.buf);
 363                 free(abs_path);
 364         }
 365         strbuf_release(&line);
 366         fclose(in);
 367 }
 368
 369 static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
 370                                    const char *src_repo, int src_baselen)
 371 {
 372         struct dirent *de;
 373         struct stat buf;
 374         int src_len, dest_len;
 375         DIR *dir;
 376
 377         dir = opendir(src->buf);
 378         if (!dir)
 379                 die_errno(_("failed to open '%s'"), src->buf);
 380
 381         if (mkdir(dest->buf, 0777)) {
 382                 if (errno != EEXIST)
 383                         die_errno(_("failed to create directory '%s'"), dest->buf);
 384                 else if (stat(dest->buf, &buf))
 385                         die_errno(_("failed to stat '%s'"), dest->buf);
 386                 else if (!S_ISDIR(buf.st_mode))
 387                         die(_("%s exists and is not a directory"), dest->buf);
 388         }
 389
 390         strbuf_addch(src, '/');
 391         src_len = src->len;
 392         strbuf_addch(dest, '/');
 393         dest_len = dest->len;
 394
 395         while ((de = readdir(dir)) != NULL) {
 396                 strbuf_setlen(src, src_len);
 397                 strbuf_addstr(src, de->d_name);
 398                 strbuf_setlen(dest, dest_len);
 399                 strbuf_addstr(dest, de->d_name);
 400                 if (stat(src->buf, &buf)) {
 401                         warning (_("failed to stat %s\n"), src->buf);
 402                         continue;
 403                 }
 404                 if (S_ISDIR(buf.st_mode)) {
 405                         if (de->d_name[0] != '.')
 406                                 copy_or_link_directory(src, dest,
 407                                                        src_repo, src_baselen);
 408                         continue;
 409                 }
 410
 411                 /* Files that cannot be copied bit-for-bit... */
 412                 if (!strcmp(src->buf + src_baselen, "/info/alternates")) {
 413                         copy_alternates(src, dest, src_repo);
 414                         continue;
 415                 }
 416
 417                 if (unlink(dest->buf) && errno != ENOENT)
 418                         die_errno(_("failed to unlink '%s'"), dest->buf);
 419                 if (!option_no_hardlinks) {
 420                         if (!link(src->buf, dest->buf))
 421                                 continue;
 422                         if (option_local > 0)
 423                                 die_errno(_("failed to create link '%s'"), dest->buf);
 424                         option_no_hardlinks = 1;
 425                 }
 426                 if (copy_file_with_time(dest->buf, src->buf, 0666))
 427                         die_errno(_("failed to copy file to '%s'"), dest->buf);
 428         }
 429         closedir(dir);
 430 }
 431
 432 static void clone_local(const char *src_repo, const char *dest_repo)
 433 {
 434         if (option_shared) {
 435                 struct strbuf alt = STRBUF_INIT;
 436                 strbuf_addf(&alt, "%s/objects", src_repo);
 437                 add_to_alternates_file(alt.buf);
 438                 strbuf_release(&alt);
 439         } else {
 440                 struct strbuf src = STRBUF_INIT;
 441                 struct strbuf dest = STRBUF_INIT;
 442                 get_common_dir(&src, src_repo);
 443                 get_common_dir(&dest, dest_repo);
 444                 strbuf_addstr(&src, "/objects");
 445                 strbuf_addstr(&dest, "/objects");
 446                 copy_or_link_directory(&src, &dest, src_repo, src.len);
 447                 strbuf_release(&src);
 448                 strbuf_release(&dest);
 449         }
 450
 451         if (0 <= option_verbosity)
 452                 fprintf(stderr, _("done.\n"));
 453 }
 454
 455 static const char *junk_work_tree;
 456 static const char *junk_git_dir;
 457 static enum {
 458         JUNK_LEAVE_NONE,
 459         JUNK_LEAVE_REPO,
 460         JUNK_LEAVE_ALL
 461 } junk_mode = JUNK_LEAVE_NONE;
 462
 463 static const char junk_leave_repo_msg[] =
 464 N_("Clone succeeded, but checkout failed.\n"
 465    "You can inspect what was checked out with 'git status'\n"
 466    "and retry the checkout with 'git checkout -f HEAD'\n");
 467
 468 static void remove_junk(void)
 469 {
 470         struct strbuf sb = STRBUF_INIT;
 471
 472         switch (junk_mode) {
 473         case JUNK_LEAVE_REPO:
 474                 warning("%s", _(junk_leave_repo_msg));
 475                 /* fall-through */
 476         case JUNK_LEAVE_ALL:
 477                 return;
 478         default:
 479                 /* proceed to removal */
 480                 break;
 481         }
 482
 483         if (junk_git_dir) {
 484                 strbuf_addstr(&sb, junk_git_dir);
 485                 remove_dir_recursively(&sb, 0);
 486                 strbuf_reset(&sb);
 487         }
 488         if (junk_work_tree) {
 489                 strbuf_addstr(&sb, junk_work_tree);
 490                 remove_dir_recursively(&sb, 0);
 491                 strbuf_reset(&sb);
 492         }
 493 }
 494
 495 static void remove_junk_on_signal(int signo)
 496 {
 497         remove_junk();
 498         sigchain_pop(signo);
 499         raise(signo);
 500 }
 501
 502 static struct ref *find_remote_branch(const struct ref *refs, const char *branch)
 503 {
 504         struct ref *ref;
 505         struct strbuf head = STRBUF_INIT;
 506         strbuf_addstr(&head, "refs/heads/");
 507         strbuf_addstr(&head, branch);
 508         ref = find_ref_by_name(refs, head.buf);
 509         strbuf_release(&head);
 510
 511         if (ref)
 512                 return ref;
 513
 514         strbuf_addstr(&head, "refs/tags/");
 515         strbuf_addstr(&head, branch);
 516         ref = find_ref_by_name(refs, head.buf);
 517         strbuf_release(&head);
 518
 519         return ref;
 520 }
 521
 522 static struct ref *wanted_peer_refs(const struct ref *refs,
 523                 struct refspec *refspec)
 524 {
 525         struct ref *head = copy_ref(find_ref_by_name(refs, "HEAD"));
 526         struct ref *local_refs = head;
 527         struct ref **tail = head ? &head->next : &local_refs;
 528
 529         if (option_single_branch) {
 530                 struct ref *remote_head = NULL;
 531
 532                 if (!option_branch)
 533                         remote_head = guess_remote_head(head, refs, 0);
 534                 else {
 535                         local_refs = NULL;
 536                         tail = &local_refs;
 537                         remote_head = copy_ref(find_remote_branch(refs, option_branch));
 538                 }
 539
 540                 if (!remote_head && option_branch)
 541                         warning(_("Could not find remote branch %s to clone."),
 542                                 option_branch);
 543                 else {
 544                         get_fetch_map(remote_head, refspec, &tail, 0);
 545
 546                         /* if --branch=tag, pull the requested tag explicitly */
 547                         get_fetch_map(remote_head, tag_refspec, &tail, 0);
 548                 }
 549         } else
 550                 get_fetch_map(refs, refspec, &tail, 0);
 551
 552         if (!option_mirror && !option_single_branch)
 553                 get_fetch_map(refs, tag_refspec, &tail, 0);
 554
 555         return local_refs;
 556 }
 557
 558 static void write_remote_refs(const struct ref *local_refs)
 559 {
 560         const struct ref *r;
 561
 562         struct ref_transaction *t;
 563         struct strbuf err = STRBUF_INIT;
 564
 565         t = ref_transaction_begin(&err);
 566         if (!t)
 567                 die("%s", err.buf);
 568
 569         for (r = local_refs; r; r = r->next) {
 570                 if (!r->peer_ref)
 571                         continue;
 572                 if (ref_transaction_create(t, r->peer_ref->name, r->old_oid.hash,
 573                                            0, NULL, &err))
 574                         die("%s", err.buf);
 575         }
 576
 577         if (initial_ref_transaction_commit(t, &err))
 578                 die("%s", err.buf);
 579
 580         strbuf_release(&err);
 581         ref_transaction_free(t);
 582 }
 583
 584 static void write_followtags(const struct ref *refs, const char *msg)
 585 {
 586         const struct ref *ref;
 587         for (ref = refs; ref; ref = ref->next) {
 588                 if (!starts_with(ref->name, "refs/tags/"))
 589                         continue;
 590                 if (ends_with(ref->name, "^{}"))
 591                         continue;
 592                 if (!has_object_file(&ref->old_oid))
 593                         continue;
 594                 update_ref(msg, ref->name, ref->old_oid.hash,
 595                            NULL, 0, UPDATE_REFS_DIE_ON_ERR);
 596         }
 597 }
 598
 599 static int iterate_ref_map(void *cb_data, unsigned char sha1[20])
 600 {
 601         struct ref **rm = cb_data;
 602         struct ref *ref = *rm;
 603
 604         /*
 605          * Skip anything missing a peer_ref, which we are not
 606          * actually going to write a ref for.
 607          */
 608         while (ref && !ref->peer_ref)
 609                 ref = ref->next;
 610         /* Returning -1 notes "end of list" to the caller. */
 611         if (!ref)
 612                 return -1;
 613
 614         hashcpy(sha1, ref->old_oid.hash);
 615         *rm = ref->next;
 616         return 0;
 617 }
 618
 619 static void update_remote_refs(const struct ref *refs,
 620                                const struct ref *mapped_refs,
 621                                const struct ref *remote_head_points_at,
 622                                const char *branch_top,
 623                                const char *msg,
 624                                struct transport *transport,
 625                                int check_connectivity)
 626 {
 627         const struct ref *rm = mapped_refs;
 628
 629         if (check_connectivity) {
 630                 struct check_connected_options opt = CHECK_CONNECTED_INIT;
 631
 632                 opt.transport = transport;
 633                 opt.progress = transport->progress;
 634
 635                 if (check_connected(iterate_ref_map, &rm, &opt))
 636                         die(_("remote did not send all necessary objects"));
 637         }
 638
 639         if (refs) {
 640                 write_remote_refs(mapped_refs);
 641                 if (option_single_branch)
 642                         write_followtags(refs, msg);
 643         }
 644
 645         if (remote_head_points_at && !option_bare) {
 646                 struct strbuf head_ref = STRBUF_INIT;
 647                 strbuf_addstr(&head_ref, branch_top);
 648                 strbuf_addstr(&head_ref, "HEAD");
 649                 if (create_symref(head_ref.buf,
 650                                   remote_head_points_at->peer_ref->name,
 651                                   msg) < 0)
 652                         die(_("unable to update %s"), head_ref.buf);
 653                 strbuf_release(&head_ref);
 654         }
 655 }
 656
 657 static void update_head(const struct ref *our, const struct ref *remote,
 658                         const char *msg)
 659 {
 660         const char *head;
 661         if (our && skip_prefix(our->name, "refs/heads/", &head)) {
 662                 /* Local default branch link */
 663                 if (create_symref("HEAD", our->name, NULL) < 0)
 664                         die(_("unable to update HEAD"));
 665                 if (!option_bare) {
 666                         update_ref(msg, "HEAD", our->old_oid.hash, NULL, 0,
 667                                    UPDATE_REFS_DIE_ON_ERR);
 668                         install_branch_config(0, head, option_origin, our->name);
 669                 }
 670         } else if (our) {
 671                 struct commit *c = lookup_commit_reference(our->old_oid.hash);
 672                 /* --branch specifies a non-branch (i.e. tags), detach HEAD */
 673                 update_ref(msg, "HEAD", c->object.oid.hash,
 674                            NULL, REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
 675         } else if (remote) {
 676                 /*
 677                  * We know remote HEAD points to a non-branch, or
 678                  * HEAD points to a branch but we don't know which one.
 679                  * Detach HEAD in all these cases.
 680                  */
 681                 update_ref(msg, "HEAD", remote->old_oid.hash,
 682                            NULL, REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
 683         }
 684 }
 685
 686 static int checkout(void)
 687 {
 688         unsigned char sha1[20];
 689         char *head;
 690         struct lock_file *lock_file;
 691         struct unpack_trees_options opts;
 692         struct tree *tree;
 693         struct tree_desc t;
 694         int err = 0;
 695
 696         if (option_no_checkout)
 697                 return 0;
 698
 699         head = resolve_refdup("HEAD", RESOLVE_REF_READING, sha1, NULL);
 700         if (!head) {
 701                 warning(_("remote HEAD refers to nonexistent ref, "
 702                           "unable to checkout.\n"));
 703                 return 0;
 704         }
 705         if (!strcmp(head, "HEAD")) {
 706                 if (advice_detached_head)
 707                         detach_advice(sha1_to_hex(sha1));
 708         } else {
 709                 if (!starts_with(head, "refs/heads/"))
 710                         die(_("HEAD not found below refs/heads!"));
 711         }
 712         free(head);
 713
 714         /* We need to be in the new work tree for the checkout */
 715         setup_work_tree();
 716
 717         lock_file = xcalloc(1, sizeof(struct lock_file));
 718         hold_locked_index(lock_file, 1);
 719
 720         memset(&opts, 0, sizeof opts);
 721         opts.update = 1;
 722         opts.merge = 1;
 723         opts.fn = oneway_merge;
 724         opts.verbose_update = (option_verbosity >= 0);
 725         opts.src_index = &the_index;
 726         opts.dst_index = &the_index;
 727
 728         tree = parse_tree_indirect(sha1);
 729         parse_tree(tree);
 730         init_tree_desc(&t, tree->buffer, tree->size);
 731         if (unpack_trees(1, &t, &opts) < 0)
 732                 die(_("unable to checkout working tree"));
 733
 734         if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
 735                 die(_("unable to write new index file"));
 736
 737         err |= run_hook_le(NULL, "post-checkout", sha1_to_hex(null_sha1),
 738                            sha1_to_hex(sha1), "1", NULL);
 739
 740         if (!err && option_recursive) {
 741                 struct argv_array args = ARGV_ARRAY_INIT;
 742                 argv_array_pushl(&args, "submodule", "update", "--init", "--recursive", NULL);
 743
 744                 if (option_shallow_submodules == 1)
 745                         argv_array_push(&args, "--depth=1");
 746
 747                 if (max_jobs != -1)
 748                         argv_array_pushf(&args, "--jobs=%d", max_jobs);
 749
 750                 err = run_command_v_opt(args.argv, RUN_GIT_CMD);
 751                 argv_array_clear(&args);
 752         }
 753
 754         return err;
 755 }
 756
 757 static int write_one_config(const char *key, const char *value, void *data)
 758 {
 759         return git_config_set_multivar_gently(key, value ? value : "true", "^$", 0);
 760 }
 761
 762 static void write_config(struct string_list *config)
 763 {
 764         int i;
 765
 766         for (i = 0; i < config->nr; i++) {
 767                 if (git_config_parse_parameter(config->items[i].string,
 768                                                write_one_config, NULL) < 0)
 769                         die(_("unable to write parameters to config file"));
 770         }
 771 }
 772
 773 static void write_refspec_config(const char *src_ref_prefix,
 774                 const struct ref *our_head_points_at,
 775                 const struct ref *remote_head_points_at,
 776                 struct strbuf *branch_top)
 777 {
 778         struct strbuf key = STRBUF_INIT;
 779         struct strbuf value = STRBUF_INIT;
 780
 781         if (option_mirror || !option_bare) {
 782                 if (option_single_branch && !option_mirror) {
 783                         if (option_branch) {
 784                                 if (starts_with(our_head_points_at->name, "refs/tags/"))
 785                                         strbuf_addf(&value, "+%s:%s", our_head_points_at->name,
 786                                                 our_head_points_at->name);
 787                                 else
 788                                         strbuf_addf(&value, "+%s:%s%s", our_head_points_at->name,
 789                                                 branch_top->buf, option_branch);
 790                         } else if (remote_head_points_at) {
 791                                 const char *head = remote_head_points_at->name;
 792                                 if (!skip_prefix(head, "refs/heads/", &head))
 793                                         die("BUG: remote HEAD points at non-head?");
 794
 795                                 strbuf_addf(&value, "+%s:%s%s", remote_head_points_at->name,
 796                                                 branch_top->buf, head);
 797                         }
 798                         /*
 799                          * otherwise, the next "git fetch" will
 800                          * simply fetch from HEAD without updating
 801                          * any remote-tracking branch, which is what
 802                          * we want.
 803                          */
 804                 } else {
 805                         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top->buf);
 806                 }
 807                 /* Configure the remote */
 808                 if (value.len) {
 809                         strbuf_addf(&key, "remote.%s.fetch", option_origin);
 810                         git_config_set_multivar(key.buf, value.buf, "^$", 0);
 811                         strbuf_reset(&key);
 812
 813                         if (option_mirror) {
 814                                 strbuf_addf(&key, "remote.%s.mirror", option_origin);
 815                                 git_config_set(key.buf, "true");
 816                                 strbuf_reset(&key);
 817                         }
 818                 }
 819         }
 820
 821         strbuf_release(&key);
 822         strbuf_release(&value);
 823 }
 824
 825 static void dissociate_from_references(void)
 826 {
 827         static const char* argv[] = { "repack", "-a", "-d", NULL };
 828         char *alternates = git_pathdup("objects/info/alternates");
 829
 830         if (!access(alternates, F_OK)) {
 831                 if (run_command_v_opt(argv, RUN_GIT_CMD|RUN_COMMAND_NO_STDIN))
 832                         die(_("cannot repack to clean up"));
 833                 if (unlink(alternates) && errno != ENOENT)
 834                         die_errno(_("cannot unlink temporary alternates file"));
 835         }
 836         free(alternates);
 837 }
 838
 839 int cmd_clone(int argc, const char **argv, const char *prefix)
 840 {
 841         int is_bundle = 0, is_local;
 842         struct stat buf;
 843         const char *repo_name, *repo, *work_tree, *git_dir;
 844         char *path, *dir;
 845         int dest_exists;
 846         const struct ref *refs, *remote_head;
 847         const struct ref *remote_head_points_at;
 848         const struct ref *our_head_points_at;
 849         struct ref *mapped_refs;
 850         const struct ref *ref;
 851         struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
 852         struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
 853         struct transport *transport = NULL;
 854         const char *src_ref_prefix = "refs/heads/";
 855         struct remote *remote;
 856         int err = 0, complete_refs_before_fetch = 1;
 857
 858         struct refspec *refspec;
 859         const char *fetch_pattern;
 860
 861         packet_trace_identity("clone");
 862         argc = parse_options(argc, argv, prefix, builtin_clone_options,
 863                              builtin_clone_usage, 0);
 864
 865         if (argc > 2)
 866                 usage_msg_opt(_("Too many arguments."),
 867                         builtin_clone_usage, builtin_clone_options);
 868
 869         if (argc == 0)
 870                 usage_msg_opt(_("You must specify a repository to clone."),
 871                         builtin_clone_usage, builtin_clone_options);
 872
 873         if (option_single_branch == -1)
 874                 option_single_branch = option_depth ? 1 : 0;
 875
 876         if (option_mirror)
 877                 option_bare = 1;
 878
 879         if (option_bare) {
 880                 if (option_origin)
 881                         die(_("--bare and --origin %s options are incompatible."),
 882                             option_origin);
 883                 if (real_git_dir)
 884                         die(_("--bare and --separate-git-dir are incompatible."));
 885                 option_no_checkout = 1;
 886         }
 887
 888         if (!option_origin)
 889                 option_origin = "origin";
 890
 891         repo_name = argv[0];
 892
 893         path = get_repo_path(repo_name, &is_bundle);
 894         if (path)
 895                 repo = xstrdup(absolute_path(repo_name));
 896         else if (!strchr(repo_name, ':'))
 897                 die(_("repository '%s' does not exist"), repo_name);
 898         else
 899                 repo = repo_name;
 900
 901         /* no need to be strict, transport_set_option() will validate it again */
 902         if (option_depth && atoi(option_depth) < 1)
 903                 die(_("depth %s is not a positive number"), option_depth);
 904
 905         if (argc == 2)
 906                 dir = xstrdup(argv[1]);
 907         else
 908                 dir = guess_dir_name(repo_name, is_bundle, option_bare);
 909         strip_trailing_slashes(dir);
 910
 911         dest_exists = !stat(dir, &buf);
 912         if (dest_exists && !is_empty_dir(dir))
 913                 die(_("destination path '%s' already exists and is not "
 914                         "an empty directory."), dir);
 915
 916         strbuf_addf(&reflog_msg, "clone: from %s", repo);
 917
 918         if (option_bare)
 919                 work_tree = NULL;
 920         else {
 921                 work_tree = getenv("GIT_WORK_TREE");
 922                 if (work_tree && !stat(work_tree, &buf))
 923                         die(_("working tree '%s' already exists."), work_tree);
 924         }
 925
 926         if (option_bare || work_tree)
 927                 git_dir = xstrdup(dir);
 928         else {
 929                 work_tree = dir;
 930                 git_dir = mkpathdup("%s/.git", dir);
 931         }
 932
 933         atexit(remove_junk);
 934         sigchain_push_common(remove_junk_on_signal);
 935
 936         if (!option_bare) {
 937                 if (safe_create_leading_directories_const(work_tree) < 0)
 938                         die_errno(_("could not create leading directories of '%s'"),
 939                                   work_tree);
 940                 if (!dest_exists && mkdir(work_tree, 0777))
 941                         die_errno(_("could not create work tree dir '%s'"),
 942                                   work_tree);
 943                 junk_work_tree = work_tree;
 944                 set_git_work_tree(work_tree);
 945         }
 946
 947         junk_git_dir = git_dir;
 948         if (safe_create_leading_directories_const(git_dir) < 0)
 949                 die(_("could not create leading directories of '%s'"), git_dir);
 950
 951         set_git_dir_init(git_dir, real_git_dir, 0);
 952         if (real_git_dir) {
 953                 git_dir = real_git_dir;
 954                 junk_git_dir = real_git_dir;
 955         }
 956
 957         if (0 <= option_verbosity) {
 958                 if (option_bare)
 959                         fprintf(stderr, _("Cloning into bare repository '%s'...\n"), dir);
 960                 else
 961                         fprintf(stderr, _("Cloning into '%s'...\n"), dir);
 962         }
 963         init_db(option_template, INIT_DB_QUIET);
 964         write_config(&option_config);
 965
 966         git_config(git_default_config, NULL);
 967
 968         if (option_bare) {
 969                 if (option_mirror)
 970                         src_ref_prefix = "refs/";
 971                 strbuf_addstr(&branch_top, src_ref_prefix);
 972
 973                 git_config_set("core.bare", "true");
 974         } else {
 975                 strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
 976         }
 977
 978         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
 979         strbuf_addf(&key, "remote.%s.url", option_origin);
 980         git_config_set(key.buf, repo);
 981         strbuf_reset(&key);
 982
 983         if (option_reference.nr)
 984                 setup_reference();
 985
 986         fetch_pattern = value.buf;
 987         refspec = parse_fetch_refspec(1, &fetch_pattern);
 988
 989         strbuf_reset(&value);
 990
 991         remote = remote_get(option_origin);
 992         transport = transport_get(remote, remote->url[0]);
 993         transport_set_verbosity(transport, option_verbosity, option_progress);
 994         transport->family = family;
 995
 996         path = get_repo_path(remote->url[0], &is_bundle);
 997         is_local = option_local != 0 && path && !is_bundle;
 998         if (is_local) {
 999                 if (option_depth)
1000                         warning(_("--depth is ignored in local clones; use file:// instead."));
1001                 if (!access(mkpath("%s/shallow", path), F_OK)) {
1002                         if (option_local > 0)
1003                                 warning(_("source repository is shallow, ignoring --local"));
1004                         is_local = 0;
1005                 }
1006         }
1007         if (option_local > 0 && !is_local)
1008                 warning(_("--local is ignored"));
1009         transport->cloning = 1;
1010
1011         if (!transport->get_refs_list || (!is_local && !transport->fetch))
1012                 die(_("Don't know how to clone %s"), transport->url);
1013
1014         transport_set_option(transport, TRANS_OPT_KEEP, "yes");
1015
1016         if (option_depth)
1017                 transport_set_option(transport, TRANS_OPT_DEPTH,
1018                                      option_depth);
1019         if (option_single_branch)
1020                 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
1021
1022         if (option_upload_pack)
1023                 transport_set_option(transport, TRANS_OPT_UPLOADPACK,
1024                                      option_upload_pack);
1025
1026         if (transport->smart_options && !option_depth)
1027                 transport->smart_options->check_self_contained_and_connected = 1;
1028
1029         refs = transport_get_remote_refs(transport);
1030
1031         if (refs) {
1032                 mapped_refs = wanted_peer_refs(refs, refspec);
1033                 /*
1034                  * transport_get_remote_refs() may return refs with null sha-1
1035                  * in mapped_refs (see struct transport->get_refs_list
1036                  * comment). In that case we need fetch it early because
1037                  * remote_head code below relies on it.
1038                  *
1039                  * for normal clones, transport_get_remote_refs() should
1040                  * return reliable ref set, we can delay cloning until after
1041                  * remote HEAD check.
1042                  */
1043                 for (ref = refs; ref; ref = ref->next)
1044                         if (is_null_oid(&ref->old_oid)) {
1045                                 complete_refs_before_fetch = 0;
1046                                 break;
1047                         }
1048
1049                 if (!is_local && !complete_refs_before_fetch)
1050                         transport_fetch_refs(transport, mapped_refs);
1051
1052                 remote_head = find_ref_by_name(refs, "HEAD");
1053                 remote_head_points_at =
1054                         guess_remote_head(remote_head, mapped_refs, 0);
1055
1056                 if (option_branch) {
1057                         our_head_points_at =
1058                                 find_remote_branch(mapped_refs, option_branch);
1059
1060                         if (!our_head_points_at)
1061                                 die(_("Remote branch %s not found in upstream %s"),
1062                                     option_branch, option_origin);
1063                 }
1064                 else
1065                         our_head_points_at = remote_head_points_at;
1066         }
1067         else {
1068                 if (option_branch)
1069                         die(_("Remote branch %s not found in upstream %s"),
1070                                         option_branch, option_origin);
1071
1072                 warning(_("You appear to have cloned an empty repository."));
1073                 mapped_refs = NULL;
1074                 our_head_points_at = NULL;
1075                 remote_head_points_at = NULL;
1076                 remote_head = NULL;
1077                 option_no_checkout = 1;
1078                 if (!option_bare)
1079                         install_branch_config(0, "master", option_origin,
1080                                               "refs/heads/master");
1081         }
1082
1083         write_refspec_config(src_ref_prefix, our_head_points_at,
1084                         remote_head_points_at, &branch_top);
1085
1086         if (is_local)
1087                 clone_local(path, git_dir);
1088         else if (refs && complete_refs_before_fetch)
1089                 transport_fetch_refs(transport, mapped_refs);
1090
1091         update_remote_refs(refs, mapped_refs, remote_head_points_at,
1092                            branch_top.buf, reflog_msg.buf, transport, !is_local);
1093
1094         update_head(our_head_points_at, remote_head, reflog_msg.buf);
1095
1096         transport_unlock_pack(transport);
1097         transport_disconnect(transport);
1098
1099         if (option_dissociate) {
1100                 close_all_packs();
1101                 dissociate_from_references();
1102         }
1103
1104         junk_mode = JUNK_LEAVE_REPO;
1105         err = checkout();
1106
1107         strbuf_release(&reflog_msg);
1108         strbuf_release(&branch_top);
1109         strbuf_release(&key);
1110         strbuf_release(&value);
1111         junk_mode = JUNK_LEAVE_ALL;
1112
1113         free(refspec);
1114         return err;
1115 }