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