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 struct string_list option_config;
  51 static struct string_list option_reference;
  52 static int option_dissociate;
  53
  54 static struct option builtin_clone_options[] = {
  55         OPT__VERBOSITY(&option_verbosity),
  56         OPT_BOOL(0, "progress", &option_progress,
  57                  N_("force progress reporting")),
  58         OPT_BOOL('n', "no-checkout", &option_no_checkout,
  59                  N_("don't create a checkout")),
  60         OPT_BOOL(0, "bare", &option_bare, N_("create a bare repository")),
  61         OPT_HIDDEN_BOOL(0, "naked", &option_bare,
  62                         N_("create a bare repository")),
  63         OPT_BOOL(0, "mirror", &option_mirror,
  64                  N_("create a mirror repository (implies bare)")),
  65         OPT_BOOL('l', "local", &option_local,
  66                 N_("to clone from a local repository")),
  67         OPT_BOOL(0, "no-hardlinks", &option_no_hardlinks,
  68                     N_("don't use local hardlinks, always copy")),
  69         OPT_BOOL('s', "shared", &option_shared,
  70                     N_("setup as shared repository")),
  71         OPT_BOOL(0, "recursive", &option_recursive,
  72                     N_("initialize submodules in the clone")),
  73         OPT_BOOL(0, "recurse-submodules", &option_recursive,
  74                     N_("initialize submodules in the clone")),
  75         OPT_STRING(0, "template", &option_template, N_("template-directory"),
  76                    N_("directory from which templates will be used")),
  77         OPT_STRING_LIST(0, "reference", &option_reference, N_("repo"),
  78                         N_("reference repository")),
  79         OPT_BOOL(0, "dissociate", &option_dissociate,
  80                  N_("use --reference only while cloning")),
  81         OPT_STRING('o', "origin", &option_origin, N_("name"),
  82                    N_("use <name> instead of 'origin' to track upstream")),
  83         OPT_STRING('b', "branch", &option_branch, N_("branch"),
  84                    N_("checkout <branch> instead of the remote's HEAD")),
  85         OPT_STRING('u', "upload-pack", &option_upload_pack, N_("path"),
  86                    N_("path to git-upload-pack on the remote")),
  87         OPT_STRING(0, "depth", &option_depth, N_("depth"),
  88                     N_("create a shallow clone of that depth")),
  89         OPT_BOOL(0, "single-branch", &option_single_branch,
  90                     N_("clone only one branch, HEAD or --branch")),
  91         OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
  92                    N_("separate git dir from working tree")),
  93         OPT_STRING_LIST('c', "config", &option_config, N_("key=value"),
  94                         N_("set config inside the new repository")),
  95         OPT_END()
  96 };
  97
  98 static const char *argv_submodule[] = {
  99         "submodule", "update", "--init", "--recursive", NULL
 100 };
 101
 102 static const char *get_repo_path_1(struct strbuf *path, int *is_bundle)
 103 {
 104         static char *suffix[] = { "/.git", "", ".git/.git", ".git" };
 105         static char *bundle_suffix[] = { ".bundle", "" };
 106         size_t baselen = path->len;
 107         struct stat st;
 108         int i;
 109
 110         for (i = 0; i < ARRAY_SIZE(suffix); i++) {
 111                 strbuf_setlen(path, baselen);
 112                 strbuf_addstr(path, suffix[i]);
 113                 if (stat(path->buf, &st))
 114                         continue;
 115                 if (S_ISDIR(st.st_mode) && is_git_directory(path->buf)) {
 116                         *is_bundle = 0;
 117                         return path->buf;
 118                 } else if (S_ISREG(st.st_mode) && st.st_size > 8) {
 119                         /* Is it a "gitfile"? */
 120                         char signature[8];
 121                         const char *dst;
 122                         int len, fd = open(path->buf, O_RDONLY);
 123                         if (fd < 0)
 124                                 continue;
 125                         len = read_in_full(fd, signature, 8);
 126                         close(fd);
 127                         if (len != 8 || strncmp(signature, "gitdir: ", 8))
 128                                 continue;
 129                         dst = read_gitfile(path->buf);
 130                         if (dst) {
 131                                 *is_bundle = 0;
 132                                 return dst;
 133                         }
 134                 }
 135         }
 136
 137         for (i = 0; i < ARRAY_SIZE(bundle_suffix); i++) {
 138                 strbuf_setlen(path, baselen);
 139                 strbuf_addstr(path, bundle_suffix[i]);
 140                 if (!stat(path->buf, &st) && S_ISREG(st.st_mode)) {
 141                         *is_bundle = 1;
 142                         return path->buf;
 143                 }
 144         }
 145
 146         return NULL;
 147 }
 148
 149 static char *get_repo_path(const char *repo, int *is_bundle)
 150 {
 151         struct strbuf path = STRBUF_INIT;
 152         const char *raw;
 153         char *canon;
 154
 155         strbuf_addstr(&path, repo);
 156         raw = get_repo_path_1(&path, is_bundle);
 157         canon = raw ? xstrdup(absolute_path(raw)) : NULL;
 158         strbuf_release(&path);
 159         return canon;
 160 }
 161
 162 static char *guess_dir_name(const char *repo, int is_bundle, int is_bare)
 163 {
 164         const char *end = repo + strlen(repo), *start, *ptr;
 165         size_t len;
 166         char *dir;
 167
 168         /*
 169          * Skip scheme.
 170          */
 171         start = strstr(repo, "://");
 172         if (start == NULL)
 173                 start = repo;
 174         else
 175                 start += 3;
 176
 177         /*
 178          * Skip authentication data. The stripping does happen
 179          * greedily, such that we strip up to the last '@' inside
 180          * the host part.
 181          */
 182         for (ptr = start; ptr < end && !is_dir_sep(*ptr); ptr++) {
 183                 if (*ptr == '@')
 184                         start = ptr + 1;
 185         }
 186
 187         /*
 188          * Strip trailing spaces, slashes and /.git
 189          */
 190         while (start < end && (is_dir_sep(end[-1]) || isspace(end[-1])))
 191                 end--;
 192         if (end - start > 5 && is_dir_sep(end[-5]) &&
 193             !strncmp(end - 4, ".git", 4)) {
 194                 end -= 5;
 195                 while (start < end && is_dir_sep(end[-1]))
 196                         end--;
 197         }
 198
 199         /*
 200          * Strip trailing port number if we've got only a
 201          * hostname (that is, there is no dir separator but a
 202          * colon). This check is required such that we do not
 203          * strip URI's like '/foo/bar:2222.git', which should
 204          * result in a dir '2222' being guessed due to backwards
 205          * compatibility.
 206          */
 207         if (memchr(start, '/', end - start) == NULL
 208             && memchr(start, ':', end - start) != NULL) {
 209                 ptr = end;
 210                 while (start < ptr && isdigit(ptr[-1]) && ptr[-1] != ':')
 211                         ptr--;
 212                 if (start < ptr && ptr[-1] == ':')
 213                         end = ptr - 1;
 214         }
 215
 216         /*
 217          * Find last component. To remain backwards compatible we
 218          * also regard colons as path separators, such that
 219          * cloning a repository 'foo:bar.git' would result in a
 220          * directory 'bar' being guessed.
 221          */
 222         ptr = end;
 223         while (start < ptr && !is_dir_sep(ptr[-1]) && ptr[-1] != ':')
 224                 ptr--;
 225         start = ptr;
 226
 227         /*
 228          * Strip .{bundle,git}.
 229          */
 230         len = end - start;
 231         strip_suffix_mem(start, &len, is_bundle ? ".bundle" : ".git");
 232
 233         if (!len || (len == 1 && *start == '/'))
 234             die("No directory name could be guessed.\n"
 235                 "Please specify a directory on the command line");
 236
 237         if (is_bare)
 238                 dir = xstrfmt("%.*s.git", (int)len, start);
 239         else
 240                 dir = xstrndup(start, len);
 241         /*
 242          * Replace sequences of 'control' characters and whitespace
 243          * with one ascii space, remove leading and trailing spaces.
 244          */
 245         if (*dir) {
 246                 char *out = dir;
 247                 int prev_space = 1 /* strip leading whitespace */;
 248                 for (end = dir; *end; ++end) {
 249                         char ch = *end;
 250                         if ((unsigned char)ch < '\x20')
 251                                 ch = '\x20';
 252                         if (isspace(ch)) {
 253                                 if (prev_space)
 254                                         continue;
 255                                 prev_space = 1;
 256                         } else
 257                                 prev_space = 0;
 258                         *out++ = ch;
 259                 }
 260                 *out = '\0';
 261                 if (out > dir && prev_space)
 262                         out[-1] = '\0';
 263         }
 264         return dir;
 265 }
 266
 267 static void strip_trailing_slashes(char *dir)
 268 {
 269         char *end = dir + strlen(dir);
 270
 271         while (dir < end - 1 && is_dir_sep(end[-1]))
 272                 end--;
 273         *end = '\0';
 274 }
 275
 276 static int add_one_reference(struct string_list_item *item, void *cb_data)
 277 {
 278         char *ref_git;
 279         const char *repo;
 280         struct strbuf alternate = STRBUF_INIT;
 281
 282         /* Beware: read_gitfile(), real_path() and mkpath() return static buffer */
 283         ref_git = xstrdup(real_path(item->string));
 284
 285         repo = read_gitfile(ref_git);
 286         if (!repo)
 287                 repo = read_gitfile(mkpath("%s/.git", ref_git));
 288         if (repo) {
 289                 free(ref_git);
 290                 ref_git = xstrdup(repo);
 291         }
 292
 293         if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
 294                 char *ref_git_git = mkpathdup("%s/.git", ref_git);
 295                 free(ref_git);
 296                 ref_git = ref_git_git;
 297         } else if (!is_directory(mkpath("%s/objects", ref_git)))
 298                 die(_("reference repository '%s' is not a local repository."),
 299                     item->string);
 300
 301         if (!access(mkpath("%s/shallow", ref_git), F_OK))
 302                 die(_("reference repository '%s' is shallow"), item->string);
 303
 304         if (!access(mkpath("%s/info/grafts", ref_git), F_OK))
 305                 die(_("reference repository '%s' is grafted"), item->string);
 306
 307         strbuf_addf(&alternate, "%s/objects", ref_git);
 308         add_to_alternates_file(alternate.buf);
 309         strbuf_release(&alternate);
 310         free(ref_git);
 311         return 0;
 312 }
 313
 314 static void setup_reference(void)
 315 {
 316         for_each_string_list(&option_reference, add_one_reference, NULL);
 317 }
 318
 319 static void copy_alternates(struct strbuf *src, struct strbuf *dst,
 320                             const char *src_repo)
 321 {
 322         /*
 323          * Read from the source objects/info/alternates file
 324          * and copy the entries to corresponding file in the
 325          * destination repository with add_to_alternates_file().
 326          * Both src and dst have "$path/objects/info/alternates".
 327          *
 328          * Instead of copying bit-for-bit from the original,
 329          * we need to append to existing one so that the already
 330          * created entry via "clone -s" is not lost, and also
 331          * to turn entries with paths relative to the original
 332          * absolute, so that they can be used in the new repository.
 333          */
 334         FILE *in = fopen(src->buf, "r");
 335         struct strbuf line = STRBUF_INIT;
 336
 337         while (strbuf_getline(&line, in, '\n') != EOF) {
 338                 char *abs_path;
 339                 if (!line.len || line.buf[0] == '#')
 340                         continue;
 341                 if (is_absolute_path(line.buf)) {
 342                         add_to_alternates_file(line.buf);
 343                         continue;
 344                 }
 345                 abs_path = mkpathdup("%s/objects/%s", src_repo, line.buf);
 346                 normalize_path_copy(abs_path, abs_path);
 347                 add_to_alternates_file(abs_path);
 348                 free(abs_path);
 349         }
 350         strbuf_release(&line);
 351         fclose(in);
 352 }
 353
 354 static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
 355                                    const char *src_repo, int src_baselen)
 356 {
 357         struct dirent *de;
 358         struct stat buf;
 359         int src_len, dest_len;
 360         DIR *dir;
 361
 362         dir = opendir(src->buf);
 363         if (!dir)
 364                 die_errno(_("failed to open '%s'"), src->buf);
 365
 366         if (mkdir(dest->buf, 0777)) {
 367                 if (errno != EEXIST)
 368                         die_errno(_("failed to create directory '%s'"), dest->buf);
 369                 else if (stat(dest->buf, &buf))
 370                         die_errno(_("failed to stat '%s'"), dest->buf);
 371                 else if (!S_ISDIR(buf.st_mode))
 372                         die(_("%s exists and is not a directory"), dest->buf);
 373         }
 374
 375         strbuf_addch(src, '/');
 376         src_len = src->len;
 377         strbuf_addch(dest, '/');
 378         dest_len = dest->len;
 379
 380         while ((de = readdir(dir)) != NULL) {
 381                 strbuf_setlen(src, src_len);
 382                 strbuf_addstr(src, de->d_name);
 383                 strbuf_setlen(dest, dest_len);
 384                 strbuf_addstr(dest, de->d_name);
 385                 if (stat(src->buf, &buf)) {
 386                         warning (_("failed to stat %s\n"), src->buf);
 387                         continue;
 388                 }
 389                 if (S_ISDIR(buf.st_mode)) {
 390                         if (de->d_name[0] != '.')
 391                                 copy_or_link_directory(src, dest,
 392                                                        src_repo, src_baselen);
 393                         continue;
 394                 }
 395
 396                 /* Files that cannot be copied bit-for-bit... */
 397                 if (!strcmp(src->buf + src_baselen, "/info/alternates")) {
 398                         copy_alternates(src, dest, src_repo);
 399                         continue;
 400                 }
 401
 402                 if (unlink(dest->buf) && errno != ENOENT)
 403                         die_errno(_("failed to unlink '%s'"), dest->buf);
 404                 if (!option_no_hardlinks) {
 405                         if (!link(src->buf, dest->buf))
 406                                 continue;
 407                         if (option_local > 0)
 408                                 die_errno(_("failed to create link '%s'"), dest->buf);
 409                         option_no_hardlinks = 1;
 410                 }
 411                 if (copy_file_with_time(dest->buf, src->buf, 0666))
 412                         die_errno(_("failed to copy file to '%s'"), dest->buf);
 413         }
 414         closedir(dir);
 415 }
 416
 417 static void clone_local(const char *src_repo, const char *dest_repo)
 418 {
 419         if (option_shared) {
 420                 struct strbuf alt = STRBUF_INIT;
 421                 strbuf_addf(&alt, "%s/objects", src_repo);
 422                 add_to_alternates_file(alt.buf);
 423                 strbuf_release(&alt);
 424         } else {
 425                 struct strbuf src = STRBUF_INIT;
 426                 struct strbuf dest = STRBUF_INIT;
 427                 strbuf_addf(&src, "%s/objects", src_repo);
 428                 strbuf_addf(&dest, "%s/objects", dest_repo);
 429                 copy_or_link_directory(&src, &dest, src_repo, src.len);
 430                 strbuf_release(&src);
 431                 strbuf_release(&dest);
 432         }
 433
 434         if (0 <= option_verbosity)
 435                 fprintf(stderr, _("done.\n"));
 436 }
 437
 438 static const char *junk_work_tree;
 439 static const char *junk_git_dir;
 440 static enum {
 441         JUNK_LEAVE_NONE,
 442         JUNK_LEAVE_REPO,
 443         JUNK_LEAVE_ALL
 444 } junk_mode = JUNK_LEAVE_NONE;
 445
 446 static const char junk_leave_repo_msg[] =
 447 N_("Clone succeeded, but checkout failed.\n"
 448    "You can inspect what was checked out with 'git status'\n"
 449    "and retry the checkout with 'git checkout -f HEAD'\n");
 450
 451 static void remove_junk(void)
 452 {
 453         struct strbuf sb = STRBUF_INIT;
 454
 455         switch (junk_mode) {
 456         case JUNK_LEAVE_REPO:
 457                 warning("%s", _(junk_leave_repo_msg));
 458                 /* fall-through */
 459         case JUNK_LEAVE_ALL:
 460                 return;
 461         default:
 462                 /* proceed to removal */
 463                 break;
 464         }
 465
 466         if (junk_git_dir) {
 467                 strbuf_addstr(&sb, junk_git_dir);
 468                 remove_dir_recursively(&sb, 0);
 469                 strbuf_reset(&sb);
 470         }
 471         if (junk_work_tree) {
 472                 strbuf_addstr(&sb, junk_work_tree);
 473                 remove_dir_recursively(&sb, 0);
 474                 strbuf_reset(&sb);
 475         }
 476 }
 477
 478 static void remove_junk_on_signal(int signo)
 479 {
 480         remove_junk();
 481         sigchain_pop(signo);
 482         raise(signo);
 483 }
 484
 485 static struct ref *find_remote_branch(const struct ref *refs, const char *branch)
 486 {
 487         struct ref *ref;
 488         struct strbuf head = STRBUF_INIT;
 489         strbuf_addstr(&head, "refs/heads/");
 490         strbuf_addstr(&head, branch);
 491         ref = find_ref_by_name(refs, head.buf);
 492         strbuf_release(&head);
 493
 494         if (ref)
 495                 return ref;
 496
 497         strbuf_addstr(&head, "refs/tags/");
 498         strbuf_addstr(&head, branch);
 499         ref = find_ref_by_name(refs, head.buf);
 500         strbuf_release(&head);
 501
 502         return ref;
 503 }
 504
 505 static struct ref *wanted_peer_refs(const struct ref *refs,
 506                 struct refspec *refspec)
 507 {
 508         struct ref *head = copy_ref(find_ref_by_name(refs, "HEAD"));
 509         struct ref *local_refs = head;
 510         struct ref **tail = head ? &head->next : &local_refs;
 511
 512         if (option_single_branch) {
 513                 struct ref *remote_head = NULL;
 514
 515                 if (!option_branch)
 516                         remote_head = guess_remote_head(head, refs, 0);
 517                 else {
 518                         local_refs = NULL;
 519                         tail = &local_refs;
 520                         remote_head = copy_ref(find_remote_branch(refs, option_branch));
 521                 }
 522
 523                 if (!remote_head && option_branch)
 524                         warning(_("Could not find remote branch %s to clone."),
 525                                 option_branch);
 526                 else {
 527                         get_fetch_map(remote_head, refspec, &tail, 0);
 528
 529                         /* if --branch=tag, pull the requested tag explicitly */
 530                         get_fetch_map(remote_head, tag_refspec, &tail, 0);
 531                 }
 532         } else
 533                 get_fetch_map(refs, refspec, &tail, 0);
 534
 535         if (!option_mirror && !option_single_branch)
 536                 get_fetch_map(refs, tag_refspec, &tail, 0);
 537
 538         return local_refs;
 539 }
 540
 541 static void write_remote_refs(const struct ref *local_refs)
 542 {
 543         const struct ref *r;
 544
 545         struct ref_transaction *t;
 546         struct strbuf err = STRBUF_INIT;
 547
 548         t = ref_transaction_begin(&err);
 549         if (!t)
 550                 die("%s", err.buf);
 551
 552         for (r = local_refs; r; r = r->next) {
 553                 if (!r->peer_ref)
 554                         continue;
 555                 if (ref_transaction_create(t, r->peer_ref->name, r->old_sha1,
 556                                            0, NULL, &err))
 557                         die("%s", err.buf);
 558         }
 559
 560         if (initial_ref_transaction_commit(t, &err))
 561                 die("%s", err.buf);
 562
 563         strbuf_release(&err);
 564         ref_transaction_free(t);
 565 }
 566
 567 static void write_followtags(const struct ref *refs, const char *msg)
 568 {
 569         const struct ref *ref;
 570         for (ref = refs; ref; ref = ref->next) {
 571                 if (!starts_with(ref->name, "refs/tags/"))
 572                         continue;
 573                 if (ends_with(ref->name, "^{}"))
 574                         continue;
 575                 if (!has_sha1_file(ref->old_sha1))
 576                         continue;
 577                 update_ref(msg, ref->name, ref->old_sha1,
 578                            NULL, 0, UPDATE_REFS_DIE_ON_ERR);
 579         }
 580 }
 581
 582 static int iterate_ref_map(void *cb_data, unsigned char sha1[20])
 583 {
 584         struct ref **rm = cb_data;
 585         struct ref *ref = *rm;
 586
 587         /*
 588          * Skip anything missing a peer_ref, which we are not
 589          * actually going to write a ref for.
 590          */
 591         while (ref && !ref->peer_ref)
 592                 ref = ref->next;
 593         /* Returning -1 notes "end of list" to the caller. */
 594         if (!ref)
 595                 return -1;
 596
 597         hashcpy(sha1, ref->old_sha1);
 598         *rm = ref->next;
 599         return 0;
 600 }
 601
 602 static void update_remote_refs(const struct ref *refs,
 603                                const struct ref *mapped_refs,
 604                                const struct ref *remote_head_points_at,
 605                                const char *branch_top,
 606                                const char *msg,
 607                                struct transport *transport,
 608                                int check_connectivity)
 609 {
 610         const struct ref *rm = mapped_refs;
 611
 612         if (check_connectivity) {
 613                 if (transport->progress)
 614                         fprintf(stderr, _("Checking connectivity... "));
 615                 if (check_everything_connected_with_transport(iterate_ref_map,
 616                                                               0, &rm, transport))
 617                         die(_("remote did not send all necessary objects"));
 618                 if (transport->progress)
 619                         fprintf(stderr, _("done.\n"));
 620         }
 621
 622         if (refs) {
 623                 write_remote_refs(mapped_refs);
 624                 if (option_single_branch)
 625                         write_followtags(refs, msg);
 626         }
 627
 628         if (remote_head_points_at && !option_bare) {
 629                 struct strbuf head_ref = STRBUF_INIT;
 630                 strbuf_addstr(&head_ref, branch_top);
 631                 strbuf_addstr(&head_ref, "HEAD");
 632                 create_symref(head_ref.buf,
 633                               remote_head_points_at->peer_ref->name,
 634                               msg);
 635         }
 636 }
 637
 638 static void update_head(const struct ref *our, const struct ref *remote,
 639                         const char *msg)
 640 {
 641         const char *head;
 642         if (our && skip_prefix(our->name, "refs/heads/", &head)) {
 643                 /* Local default branch link */
 644                 create_symref("HEAD", our->name, NULL);
 645                 if (!option_bare) {
 646                         update_ref(msg, "HEAD", our->old_sha1, NULL, 0,
 647                                    UPDATE_REFS_DIE_ON_ERR);
 648                         install_branch_config(0, head, option_origin, our->name);
 649                 }
 650         } else if (our) {
 651                 struct commit *c = lookup_commit_reference(our->old_sha1);
 652                 /* --branch specifies a non-branch (i.e. tags), detach HEAD */
 653                 update_ref(msg, "HEAD", c->object.sha1,
 654                            NULL, REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
 655         } else if (remote) {
 656                 /*
 657                  * We know remote HEAD points to a non-branch, or
 658                  * HEAD points to a branch but we don't know which one.
 659                  * Detach HEAD in all these cases.
 660                  */
 661                 update_ref(msg, "HEAD", remote->old_sha1,
 662                            NULL, REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
 663         }
 664 }
 665
 666 static int checkout(void)
 667 {
 668         unsigned char sha1[20];
 669         char *head;
 670         struct lock_file *lock_file;
 671         struct unpack_trees_options opts;
 672         struct tree *tree;
 673         struct tree_desc t;
 674         int err = 0;
 675
 676         if (option_no_checkout)
 677                 return 0;
 678
 679         head = resolve_refdup("HEAD", RESOLVE_REF_READING, sha1, NULL);
 680         if (!head) {
 681                 warning(_("remote HEAD refers to nonexistent ref, "
 682                           "unable to checkout.\n"));
 683                 return 0;
 684         }
 685         if (!strcmp(head, "HEAD")) {
 686                 if (advice_detached_head)
 687                         detach_advice(sha1_to_hex(sha1));
 688         } else {
 689                 if (!starts_with(head, "refs/heads/"))
 690                         die(_("HEAD not found below refs/heads!"));
 691         }
 692         free(head);
 693
 694         /* We need to be in the new work tree for the checkout */
 695         setup_work_tree();
 696
 697         lock_file = xcalloc(1, sizeof(struct lock_file));
 698         hold_locked_index(lock_file, 1);
 699
 700         memset(&opts, 0, sizeof opts);
 701         opts.update = 1;
 702         opts.merge = 1;
 703         opts.fn = oneway_merge;
 704         opts.verbose_update = (option_verbosity >= 0);
 705         opts.src_index = &the_index;
 706         opts.dst_index = &the_index;
 707
 708         tree = parse_tree_indirect(sha1);
 709         parse_tree(tree);
 710         init_tree_desc(&t, tree->buffer, tree->size);
 711         if (unpack_trees(1, &t, &opts) < 0)
 712                 die(_("unable to checkout working tree"));
 713
 714         if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
 715                 die(_("unable to write new index file"));
 716
 717         err |= run_hook_le(NULL, "post-checkout", sha1_to_hex(null_sha1),
 718                            sha1_to_hex(sha1), "1", NULL);
 719
 720         if (!err && option_recursive)
 721                 err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
 722
 723         return err;
 724 }
 725
 726 static int write_one_config(const char *key, const char *value, void *data)
 727 {
 728         return git_config_set_multivar(key, value ? value : "true", "^$", 0);
 729 }
 730
 731 static void write_config(struct string_list *config)
 732 {
 733         int i;
 734
 735         for (i = 0; i < config->nr; i++) {
 736                 if (git_config_parse_parameter(config->items[i].string,
 737                                                write_one_config, NULL) < 0)
 738                         die("unable to write parameters to config file");
 739         }
 740 }
 741
 742 static void write_refspec_config(const char *src_ref_prefix,
 743                 const struct ref *our_head_points_at,
 744                 const struct ref *remote_head_points_at,
 745                 struct strbuf *branch_top)
 746 {
 747         struct strbuf key = STRBUF_INIT;
 748         struct strbuf value = STRBUF_INIT;
 749
 750         if (option_mirror || !option_bare) {
 751                 if (option_single_branch && !option_mirror) {
 752                         if (option_branch) {
 753                                 if (starts_with(our_head_points_at->name, "refs/tags/"))
 754                                         strbuf_addf(&value, "+%s:%s", our_head_points_at->name,
 755                                                 our_head_points_at->name);
 756                                 else
 757                                         strbuf_addf(&value, "+%s:%s%s", our_head_points_at->name,
 758                                                 branch_top->buf, option_branch);
 759                         } else if (remote_head_points_at) {
 760                                 const char *head = remote_head_points_at->name;
 761                                 if (!skip_prefix(head, "refs/heads/", &head))
 762                                         die("BUG: remote HEAD points at non-head?");
 763
 764                                 strbuf_addf(&value, "+%s:%s%s", remote_head_points_at->name,
 765                                                 branch_top->buf, head);
 766                         }
 767                         /*
 768                          * otherwise, the next "git fetch" will
 769                          * simply fetch from HEAD without updating
 770                          * any remote-tracking branch, which is what
 771                          * we want.
 772                          */
 773                 } else {
 774                         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top->buf);
 775                 }
 776                 /* Configure the remote */
 777                 if (value.len) {
 778                         strbuf_addf(&key, "remote.%s.fetch", option_origin);
 779                         git_config_set_multivar(key.buf, value.buf, "^$", 0);
 780                         strbuf_reset(&key);
 781
 782                         if (option_mirror) {
 783                                 strbuf_addf(&key, "remote.%s.mirror", option_origin);
 784                                 git_config_set(key.buf, "true");
 785                                 strbuf_reset(&key);
 786                         }
 787                 }
 788         }
 789
 790         strbuf_release(&key);
 791         strbuf_release(&value);
 792 }
 793
 794 static void dissociate_from_references(void)
 795 {
 796         static const char* argv[] = { "repack", "-a", "-d", NULL };
 797
 798         if (run_command_v_opt(argv, RUN_GIT_CMD|RUN_COMMAND_NO_STDIN))
 799                 die(_("cannot repack to clean up"));
 800         if (unlink(git_path("objects/info/alternates")) && errno != ENOENT)
 801                 die_errno(_("cannot unlink temporary alternates file"));
 802 }
 803
 804 int cmd_clone(int argc, const char **argv, const char *prefix)
 805 {
 806         int is_bundle = 0, is_local;
 807         struct stat buf;
 808         const char *repo_name, *repo, *work_tree, *git_dir;
 809         char *path, *dir;
 810         int dest_exists;
 811         const struct ref *refs, *remote_head;
 812         const struct ref *remote_head_points_at;
 813         const struct ref *our_head_points_at;
 814         struct ref *mapped_refs;
 815         const struct ref *ref;
 816         struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
 817         struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
 818         struct transport *transport = NULL;
 819         const char *src_ref_prefix = "refs/heads/";
 820         struct remote *remote;
 821         int err = 0, complete_refs_before_fetch = 1;
 822
 823         struct refspec *refspec;
 824         const char *fetch_pattern;
 825
 826         packet_trace_identity("clone");
 827         argc = parse_options(argc, argv, prefix, builtin_clone_options,
 828                              builtin_clone_usage, 0);
 829
 830         if (argc > 2)
 831                 usage_msg_opt(_("Too many arguments."),
 832                         builtin_clone_usage, builtin_clone_options);
 833
 834         if (argc == 0)
 835                 usage_msg_opt(_("You must specify a repository to clone."),
 836                         builtin_clone_usage, builtin_clone_options);
 837
 838         if (option_single_branch == -1)
 839                 option_single_branch = option_depth ? 1 : 0;
 840
 841         if (option_mirror)
 842                 option_bare = 1;
 843
 844         if (option_bare) {
 845                 if (option_origin)
 846                         die(_("--bare and --origin %s options are incompatible."),
 847                             option_origin);
 848                 if (real_git_dir)
 849                         die(_("--bare and --separate-git-dir are incompatible."));
 850                 option_no_checkout = 1;
 851         }
 852
 853         if (!option_origin)
 854                 option_origin = "origin";
 855
 856         repo_name = argv[0];
 857
 858         path = get_repo_path(repo_name, &is_bundle);
 859         if (path)
 860                 repo = xstrdup(absolute_path(repo_name));
 861         else if (!strchr(repo_name, ':'))
 862                 die(_("repository '%s' does not exist"), repo_name);
 863         else
 864                 repo = repo_name;
 865
 866         /* no need to be strict, transport_set_option() will validate it again */
 867         if (option_depth && atoi(option_depth) < 1)
 868                 die(_("depth %s is not a positive number"), option_depth);
 869
 870         if (argc == 2)
 871                 dir = xstrdup(argv[1]);
 872         else
 873                 dir = guess_dir_name(repo_name, is_bundle, option_bare);
 874         strip_trailing_slashes(dir);
 875
 876         dest_exists = !stat(dir, &buf);
 877         if (dest_exists && !is_empty_dir(dir))
 878                 die(_("destination path '%s' already exists and is not "
 879                         "an empty directory."), dir);
 880
 881         strbuf_addf(&reflog_msg, "clone: from %s", repo);
 882
 883         if (option_bare)
 884                 work_tree = NULL;
 885         else {
 886                 work_tree = getenv("GIT_WORK_TREE");
 887                 if (work_tree && !stat(work_tree, &buf))
 888                         die(_("working tree '%s' already exists."), work_tree);
 889         }
 890
 891         if (option_bare || work_tree)
 892                 git_dir = xstrdup(dir);
 893         else {
 894                 work_tree = dir;
 895                 git_dir = mkpathdup("%s/.git", dir);
 896         }
 897
 898         atexit(remove_junk);
 899         sigchain_push_common(remove_junk_on_signal);
 900
 901         if (!option_bare) {
 902                 if (safe_create_leading_directories_const(work_tree) < 0)
 903                         die_errno(_("could not create leading directories of '%s'"),
 904                                   work_tree);
 905                 if (!dest_exists && mkdir(work_tree, 0777))
 906                         die_errno(_("could not create work tree dir '%s'"),
 907                                   work_tree);
 908                 junk_work_tree = work_tree;
 909                 set_git_work_tree(work_tree);
 910         }
 911
 912         junk_git_dir = git_dir;
 913         if (safe_create_leading_directories_const(git_dir) < 0)
 914                 die(_("could not create leading directories of '%s'"), git_dir);
 915
 916         set_git_dir_init(git_dir, real_git_dir, 0);
 917         if (real_git_dir) {
 918                 git_dir = real_git_dir;
 919                 junk_git_dir = real_git_dir;
 920         }
 921
 922         if (0 <= option_verbosity) {
 923                 if (option_bare)
 924                         fprintf(stderr, _("Cloning into bare repository '%s'...\n"), dir);
 925                 else
 926                         fprintf(stderr, _("Cloning into '%s'...\n"), dir);
 927         }
 928         init_db(option_template, INIT_DB_QUIET);
 929         write_config(&option_config);
 930
 931         git_config(git_default_config, NULL);
 932
 933         if (option_bare) {
 934                 if (option_mirror)
 935                         src_ref_prefix = "refs/";
 936                 strbuf_addstr(&branch_top, src_ref_prefix);
 937
 938                 git_config_set("core.bare", "true");
 939         } else {
 940                 strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
 941         }
 942
 943         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
 944         strbuf_addf(&key, "remote.%s.url", option_origin);
 945         git_config_set(key.buf, repo);
 946         strbuf_reset(&key);
 947
 948         if (option_reference.nr)
 949                 setup_reference();
 950         else if (option_dissociate) {
 951                 warning(_("--dissociate given, but there is no --reference"));
 952                 option_dissociate = 0;
 953         }
 954
 955         fetch_pattern = value.buf;
 956         refspec = parse_fetch_refspec(1, &fetch_pattern);
 957
 958         strbuf_reset(&value);
 959
 960         remote = remote_get(option_origin);
 961         transport = transport_get(remote, remote->url[0]);
 962         transport_set_verbosity(transport, option_verbosity, option_progress);
 963
 964         path = get_repo_path(remote->url[0], &is_bundle);
 965         is_local = option_local != 0 && path && !is_bundle;
 966         if (is_local) {
 967                 if (option_depth)
 968                         warning(_("--depth is ignored in local clones; use file:// instead."));
 969                 if (!access(mkpath("%s/shallow", path), F_OK)) {
 970                         if (option_local > 0)
 971                                 warning(_("source repository is shallow, ignoring --local"));
 972                         is_local = 0;
 973                 }
 974         }
 975         if (option_local > 0 && !is_local)
 976                 warning(_("--local is ignored"));
 977         transport->cloning = 1;
 978
 979         if (!transport->get_refs_list || (!is_local && !transport->fetch))
 980                 die(_("Don't know how to clone %s"), transport->url);
 981
 982         transport_set_option(transport, TRANS_OPT_KEEP, "yes");
 983
 984         if (option_depth)
 985                 transport_set_option(transport, TRANS_OPT_DEPTH,
 986                                      option_depth);
 987         if (option_single_branch)
 988                 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
 989
 990         if (option_upload_pack)
 991                 transport_set_option(transport, TRANS_OPT_UPLOADPACK,
 992                                      option_upload_pack);
 993
 994         if (transport->smart_options && !option_depth)
 995                 transport->smart_options->check_self_contained_and_connected = 1;
 996
 997         refs = transport_get_remote_refs(transport);
 998
 999         if (refs) {
1000                 mapped_refs = wanted_peer_refs(refs, refspec);
1001                 /*
1002                  * transport_get_remote_refs() may return refs with null sha-1
1003                  * in mapped_refs (see struct transport->get_refs_list
1004                  * comment). In that case we need fetch it early because
1005                  * remote_head code below relies on it.
1006                  *
1007                  * for normal clones, transport_get_remote_refs() should
1008                  * return reliable ref set, we can delay cloning until after
1009                  * remote HEAD check.
1010                  */
1011                 for (ref = refs; ref; ref = ref->next)
1012                         if (is_null_sha1(ref->old_sha1)) {
1013                                 complete_refs_before_fetch = 0;
1014                                 break;
1015                         }
1016
1017                 if (!is_local && !complete_refs_before_fetch)
1018                         transport_fetch_refs(transport, mapped_refs);
1019
1020                 remote_head = find_ref_by_name(refs, "HEAD");
1021                 remote_head_points_at =
1022                         guess_remote_head(remote_head, mapped_refs, 0);
1023
1024                 if (option_branch) {
1025                         our_head_points_at =
1026                                 find_remote_branch(mapped_refs, option_branch);
1027
1028                         if (!our_head_points_at)
1029                                 die(_("Remote branch %s not found in upstream %s"),
1030                                     option_branch, option_origin);
1031                 }
1032                 else
1033                         our_head_points_at = remote_head_points_at;
1034         }
1035         else {
1036                 if (option_branch)
1037                         die(_("Remote branch %s not found in upstream %s"),
1038                                         option_branch, option_origin);
1039
1040                 warning(_("You appear to have cloned an empty repository."));
1041                 mapped_refs = NULL;
1042                 our_head_points_at = NULL;
1043                 remote_head_points_at = NULL;
1044                 remote_head = NULL;
1045                 option_no_checkout = 1;
1046                 if (!option_bare)
1047                         install_branch_config(0, "master", option_origin,
1048                                               "refs/heads/master");
1049         }
1050
1051         write_refspec_config(src_ref_prefix, our_head_points_at,
1052                         remote_head_points_at, &branch_top);
1053
1054         if (is_local)
1055                 clone_local(path, git_dir);
1056         else if (refs && complete_refs_before_fetch)
1057                 transport_fetch_refs(transport, mapped_refs);
1058
1059         update_remote_refs(refs, mapped_refs, remote_head_points_at,
1060                            branch_top.buf, reflog_msg.buf, transport, !is_local);
1061
1062         update_head(our_head_points_at, remote_head, reflog_msg.buf);
1063
1064         transport_unlock_pack(transport);
1065         transport_disconnect(transport);
1066
1067         if (option_dissociate)
1068                 dissociate_from_references();
1069
1070         junk_mode = JUNK_LEAVE_REPO;
1071         err = checkout();
1072
1073         strbuf_release(&reflog_msg);
1074         strbuf_release(&branch_top);
1075         strbuf_release(&key);
1076         strbuf_release(&value);
1077         junk_mode = JUNK_LEAVE_ALL;
1078
1079         free(refspec);
1080         return err;
1081 }