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                 struct strbuf sb = STRBUF_INIT;
 299                 if (get_common_dir(&sb, ref_git))
 300                         die(_("reference repository '%s' as a linked checkout is not supported yet."),
 301                             item->string);
 302                 die(_("reference repository '%s' is not a local repository."),
 303                     item->string);
 304         }
 305
 306         if (!access(mkpath("%s/shallow", ref_git), F_OK))
 307                 die(_("reference repository '%s' is shallow"), item->string);
 308
 309         if (!access(mkpath("%s/info/grafts", ref_git), F_OK))
 310                 die(_("reference repository '%s' is grafted"), item->string);
 311
 312         strbuf_addf(&alternate, "%s/objects", ref_git);
 313         add_to_alternates_file(alternate.buf);
 314         strbuf_release(&alternate);
 315         free(ref_git);
 316         return 0;
 317 }
 318
 319 static void setup_reference(void)
 320 {
 321         for_each_string_list(&option_reference, add_one_reference, NULL);
 322 }
 323
 324 static void copy_alternates(struct strbuf *src, struct strbuf *dst,
 325                             const char *src_repo)
 326 {
 327         /*
 328          * Read from the source objects/info/alternates file
 329          * and copy the entries to corresponding file in the
 330          * destination repository with add_to_alternates_file().
 331          * Both src and dst have "$path/objects/info/alternates".
 332          *
 333          * Instead of copying bit-for-bit from the original,
 334          * we need to append to existing one so that the already
 335          * created entry via "clone -s" is not lost, and also
 336          * to turn entries with paths relative to the original
 337          * absolute, so that they can be used in the new repository.
 338          */
 339         FILE *in = fopen(src->buf, "r");
 340         struct strbuf line = STRBUF_INIT;
 341
 342         while (strbuf_getline(&line, in, '\n') != EOF) {
 343                 char *abs_path;
 344                 if (!line.len || line.buf[0] == '#')
 345                         continue;
 346                 if (is_absolute_path(line.buf)) {
 347                         add_to_alternates_file(line.buf);
 348                         continue;
 349                 }
 350                 abs_path = mkpathdup("%s/objects/%s", src_repo, line.buf);
 351                 normalize_path_copy(abs_path, abs_path);
 352                 add_to_alternates_file(abs_path);
 353                 free(abs_path);
 354         }
 355         strbuf_release(&line);
 356         fclose(in);
 357 }
 358
 359 static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
 360                                    const char *src_repo, int src_baselen)
 361 {
 362         struct dirent *de;
 363         struct stat buf;
 364         int src_len, dest_len;
 365         DIR *dir;
 366
 367         dir = opendir(src->buf);
 368         if (!dir)
 369                 die_errno(_("failed to open '%s'"), src->buf);
 370
 371         if (mkdir(dest->buf, 0777)) {
 372                 if (errno != EEXIST)
 373                         die_errno(_("failed to create directory '%s'"), dest->buf);
 374                 else if (stat(dest->buf, &buf))
 375                         die_errno(_("failed to stat '%s'"), dest->buf);
 376                 else if (!S_ISDIR(buf.st_mode))
 377                         die(_("%s exists and is not a directory"), dest->buf);
 378         }
 379
 380         strbuf_addch(src, '/');
 381         src_len = src->len;
 382         strbuf_addch(dest, '/');
 383         dest_len = dest->len;
 384
 385         while ((de = readdir(dir)) != NULL) {
 386                 strbuf_setlen(src, src_len);
 387                 strbuf_addstr(src, de->d_name);
 388                 strbuf_setlen(dest, dest_len);
 389                 strbuf_addstr(dest, de->d_name);
 390                 if (stat(src->buf, &buf)) {
 391                         warning (_("failed to stat %s\n"), src->buf);
 392                         continue;
 393                 }
 394                 if (S_ISDIR(buf.st_mode)) {
 395                         if (de->d_name[0] != '.')
 396                                 copy_or_link_directory(src, dest,
 397                                                        src_repo, src_baselen);
 398                         continue;
 399                 }
 400
 401                 /* Files that cannot be copied bit-for-bit... */
 402                 if (!strcmp(src->buf + src_baselen, "/info/alternates")) {
 403                         copy_alternates(src, dest, src_repo);
 404                         continue;
 405                 }
 406
 407                 if (unlink(dest->buf) && errno != ENOENT)
 408                         die_errno(_("failed to unlink '%s'"), dest->buf);
 409                 if (!option_no_hardlinks) {
 410                         if (!link(src->buf, dest->buf))
 411                                 continue;
 412                         if (option_local > 0)
 413                                 die_errno(_("failed to create link '%s'"), dest->buf);
 414                         option_no_hardlinks = 1;
 415                 }
 416                 if (copy_file_with_time(dest->buf, src->buf, 0666))
 417                         die_errno(_("failed to copy file to '%s'"), dest->buf);
 418         }
 419         closedir(dir);
 420 }
 421
 422 static void clone_local(const char *src_repo, const char *dest_repo)
 423 {
 424         if (option_shared) {
 425                 struct strbuf alt = STRBUF_INIT;
 426                 strbuf_addf(&alt, "%s/objects", src_repo);
 427                 add_to_alternates_file(alt.buf);
 428                 strbuf_release(&alt);
 429         } else {
 430                 struct strbuf src = STRBUF_INIT;
 431                 struct strbuf dest = STRBUF_INIT;
 432                 get_common_dir(&src, src_repo);
 433                 get_common_dir(&dest, dest_repo);
 434                 strbuf_addstr(&src, "/objects");
 435                 strbuf_addstr(&dest, "/objects");
 436                 copy_or_link_directory(&src, &dest, src_repo, src.len);
 437                 strbuf_release(&src);
 438                 strbuf_release(&dest);
 439         }
 440
 441         if (0 <= option_verbosity)
 442                 fprintf(stderr, _("done.\n"));
 443 }
 444
 445 static const char *junk_work_tree;
 446 static const char *junk_git_dir;
 447 static enum {
 448         JUNK_LEAVE_NONE,
 449         JUNK_LEAVE_REPO,
 450         JUNK_LEAVE_ALL
 451 } junk_mode = JUNK_LEAVE_NONE;
 452
 453 static const char junk_leave_repo_msg[] =
 454 N_("Clone succeeded, but checkout failed.\n"
 455    "You can inspect what was checked out with 'git status'\n"
 456    "and retry the checkout with 'git checkout -f HEAD'\n");
 457
 458 static void remove_junk(void)
 459 {
 460         struct strbuf sb = STRBUF_INIT;
 461
 462         switch (junk_mode) {
 463         case JUNK_LEAVE_REPO:
 464                 warning("%s", _(junk_leave_repo_msg));
 465                 /* fall-through */
 466         case JUNK_LEAVE_ALL:
 467                 return;
 468         default:
 469                 /* proceed to removal */
 470                 break;
 471         }
 472
 473         if (junk_git_dir) {
 474                 strbuf_addstr(&sb, junk_git_dir);
 475                 remove_dir_recursively(&sb, 0);
 476                 strbuf_reset(&sb);
 477         }
 478         if (junk_work_tree) {
 479                 strbuf_addstr(&sb, junk_work_tree);
 480                 remove_dir_recursively(&sb, 0);
 481                 strbuf_reset(&sb);
 482         }
 483 }
 484
 485 static void remove_junk_on_signal(int signo)
 486 {
 487         remove_junk();
 488         sigchain_pop(signo);
 489         raise(signo);
 490 }
 491
 492 static struct ref *find_remote_branch(const struct ref *refs, const char *branch)
 493 {
 494         struct ref *ref;
 495         struct strbuf head = STRBUF_INIT;
 496         strbuf_addstr(&head, "refs/heads/");
 497         strbuf_addstr(&head, branch);
 498         ref = find_ref_by_name(refs, head.buf);
 499         strbuf_release(&head);
 500
 501         if (ref)
 502                 return ref;
 503
 504         strbuf_addstr(&head, "refs/tags/");
 505         strbuf_addstr(&head, branch);
 506         ref = find_ref_by_name(refs, head.buf);
 507         strbuf_release(&head);
 508
 509         return ref;
 510 }
 511
 512 static struct ref *wanted_peer_refs(const struct ref *refs,
 513                 struct refspec *refspec)
 514 {
 515         struct ref *head = copy_ref(find_ref_by_name(refs, "HEAD"));
 516         struct ref *local_refs = head;
 517         struct ref **tail = head ? &head->next : &local_refs;
 518
 519         if (option_single_branch) {
 520                 struct ref *remote_head = NULL;
 521
 522                 if (!option_branch)
 523                         remote_head = guess_remote_head(head, refs, 0);
 524                 else {
 525                         local_refs = NULL;
 526                         tail = &local_refs;
 527                         remote_head = copy_ref(find_remote_branch(refs, option_branch));
 528                 }
 529
 530                 if (!remote_head && option_branch)
 531                         warning(_("Could not find remote branch %s to clone."),
 532                                 option_branch);
 533                 else {
 534                         get_fetch_map(remote_head, refspec, &tail, 0);
 535
 536                         /* if --branch=tag, pull the requested tag explicitly */
 537                         get_fetch_map(remote_head, tag_refspec, &tail, 0);
 538                 }
 539         } else
 540                 get_fetch_map(refs, refspec, &tail, 0);
 541
 542         if (!option_mirror && !option_single_branch)
 543                 get_fetch_map(refs, tag_refspec, &tail, 0);
 544
 545         return local_refs;
 546 }
 547
 548 static void write_remote_refs(const struct ref *local_refs)
 549 {
 550         const struct ref *r;
 551
 552         struct ref_transaction *t;
 553         struct strbuf err = STRBUF_INIT;
 554
 555         t = ref_transaction_begin(&err);
 556         if (!t)
 557                 die("%s", err.buf);
 558
 559         for (r = local_refs; r; r = r->next) {
 560                 if (!r->peer_ref)
 561                         continue;
 562                 if (ref_transaction_create(t, r->peer_ref->name, r->old_sha1,
 563                                            0, NULL, &err))
 564                         die("%s", err.buf);
 565         }
 566
 567         if (initial_ref_transaction_commit(t, &err))
 568                 die("%s", err.buf);
 569
 570         strbuf_release(&err);
 571         ref_transaction_free(t);
 572 }
 573
 574 static void write_followtags(const struct ref *refs, const char *msg)
 575 {
 576         const struct ref *ref;
 577         for (ref = refs; ref; ref = ref->next) {
 578                 if (!starts_with(ref->name, "refs/tags/"))
 579                         continue;
 580                 if (ends_with(ref->name, "^{}"))
 581                         continue;
 582                 if (!has_sha1_file(ref->old_sha1))
 583                         continue;
 584                 update_ref(msg, ref->name, ref->old_sha1,
 585                            NULL, 0, UPDATE_REFS_DIE_ON_ERR);
 586         }
 587 }
 588
 589 static int iterate_ref_map(void *cb_data, unsigned char sha1[20])
 590 {
 591         struct ref **rm = cb_data;
 592         struct ref *ref = *rm;
 593
 594         /*
 595          * Skip anything missing a peer_ref, which we are not
 596          * actually going to write a ref for.
 597          */
 598         while (ref && !ref->peer_ref)
 599                 ref = ref->next;
 600         /* Returning -1 notes "end of list" to the caller. */
 601         if (!ref)
 602                 return -1;
 603
 604         hashcpy(sha1, ref->old_sha1);
 605         *rm = ref->next;
 606         return 0;
 607 }
 608
 609 static void update_remote_refs(const struct ref *refs,
 610                                const struct ref *mapped_refs,
 611                                const struct ref *remote_head_points_at,
 612                                const char *branch_top,
 613                                const char *msg,
 614                                struct transport *transport,
 615                                int check_connectivity)
 616 {
 617         const struct ref *rm = mapped_refs;
 618
 619         if (check_connectivity) {
 620                 if (transport->progress)
 621                         fprintf(stderr, _("Checking connectivity... "));
 622                 if (check_everything_connected_with_transport(iterate_ref_map,
 623                                                               0, &rm, transport))
 624                         die(_("remote did not send all necessary objects"));
 625                 if (transport->progress)
 626                         fprintf(stderr, _("done.\n"));
 627         }
 628
 629         if (refs) {
 630                 write_remote_refs(mapped_refs);
 631                 if (option_single_branch)
 632                         write_followtags(refs, msg);
 633         }
 634
 635         if (remote_head_points_at && !option_bare) {
 636                 struct strbuf head_ref = STRBUF_INIT;
 637                 strbuf_addstr(&head_ref, branch_top);
 638                 strbuf_addstr(&head_ref, "HEAD");
 639                 create_symref(head_ref.buf,
 640                               remote_head_points_at->peer_ref->name,
 641                               msg);
 642         }
 643 }
 644
 645 static void update_head(const struct ref *our, const struct ref *remote,
 646                         const char *msg)
 647 {
 648         const char *head;
 649         if (our && skip_prefix(our->name, "refs/heads/", &head)) {
 650                 /* Local default branch link */
 651                 create_symref("HEAD", our->name, NULL);
 652                 if (!option_bare) {
 653                         update_ref(msg, "HEAD", our->old_sha1, NULL, 0,
 654                                    UPDATE_REFS_DIE_ON_ERR);
 655                         install_branch_config(0, head, option_origin, our->name);
 656                 }
 657         } else if (our) {
 658                 struct commit *c = lookup_commit_reference(our->old_sha1);
 659                 /* --branch specifies a non-branch (i.e. tags), detach HEAD */
 660                 update_ref(msg, "HEAD", c->object.sha1,
 661                            NULL, REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
 662         } else if (remote) {
 663                 /*
 664                  * We know remote HEAD points to a non-branch, or
 665                  * HEAD points to a branch but we don't know which one.
 666                  * Detach HEAD in all these cases.
 667                  */
 668                 update_ref(msg, "HEAD", remote->old_sha1,
 669                            NULL, REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
 670         }
 671 }
 672
 673 static int checkout(void)
 674 {
 675         unsigned char sha1[20];
 676         char *head;
 677         struct lock_file *lock_file;
 678         struct unpack_trees_options opts;
 679         struct tree *tree;
 680         struct tree_desc t;
 681         int err = 0;
 682
 683         if (option_no_checkout)
 684                 return 0;
 685
 686         head = resolve_refdup("HEAD", RESOLVE_REF_READING, sha1, NULL);
 687         if (!head) {
 688                 warning(_("remote HEAD refers to nonexistent ref, "
 689                           "unable to checkout.\n"));
 690                 return 0;
 691         }
 692         if (!strcmp(head, "HEAD")) {
 693                 if (advice_detached_head)
 694                         detach_advice(sha1_to_hex(sha1));
 695         } else {
 696                 if (!starts_with(head, "refs/heads/"))
 697                         die(_("HEAD not found below refs/heads!"));
 698         }
 699         free(head);
 700
 701         /* We need to be in the new work tree for the checkout */
 702         setup_work_tree();
 703
 704         lock_file = xcalloc(1, sizeof(struct lock_file));
 705         hold_locked_index(lock_file, 1);
 706
 707         memset(&opts, 0, sizeof opts);
 708         opts.update = 1;
 709         opts.merge = 1;
 710         opts.fn = oneway_merge;
 711         opts.verbose_update = (option_verbosity >= 0);
 712         opts.src_index = &the_index;
 713         opts.dst_index = &the_index;
 714
 715         tree = parse_tree_indirect(sha1);
 716         parse_tree(tree);
 717         init_tree_desc(&t, tree->buffer, tree->size);
 718         if (unpack_trees(1, &t, &opts) < 0)
 719                 die(_("unable to checkout working tree"));
 720
 721         if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
 722                 die(_("unable to write new index file"));
 723
 724         err |= run_hook_le(NULL, "post-checkout", sha1_to_hex(null_sha1),
 725                            sha1_to_hex(sha1), "1", NULL);
 726
 727         if (!err && option_recursive)
 728                 err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
 729
 730         return err;
 731 }
 732
 733 static int write_one_config(const char *key, const char *value, void *data)
 734 {
 735         return git_config_set_multivar(key, value ? value : "true", "^$", 0);
 736 }
 737
 738 static void write_config(struct string_list *config)
 739 {
 740         int i;
 741
 742         for (i = 0; i < config->nr; i++) {
 743                 if (git_config_parse_parameter(config->items[i].string,
 744                                                write_one_config, NULL) < 0)
 745                         die("unable to write parameters to config file");
 746         }
 747 }
 748
 749 static void write_refspec_config(const char *src_ref_prefix,
 750                 const struct ref *our_head_points_at,
 751                 const struct ref *remote_head_points_at,
 752                 struct strbuf *branch_top)
 753 {
 754         struct strbuf key = STRBUF_INIT;
 755         struct strbuf value = STRBUF_INIT;
 756
 757         if (option_mirror || !option_bare) {
 758                 if (option_single_branch && !option_mirror) {
 759                         if (option_branch) {
 760                                 if (starts_with(our_head_points_at->name, "refs/tags/"))
 761                                         strbuf_addf(&value, "+%s:%s", our_head_points_at->name,
 762                                                 our_head_points_at->name);
 763                                 else
 764                                         strbuf_addf(&value, "+%s:%s%s", our_head_points_at->name,
 765                                                 branch_top->buf, option_branch);
 766                         } else if (remote_head_points_at) {
 767                                 const char *head = remote_head_points_at->name;
 768                                 if (!skip_prefix(head, "refs/heads/", &head))
 769                                         die("BUG: remote HEAD points at non-head?");
 770
 771                                 strbuf_addf(&value, "+%s:%s%s", remote_head_points_at->name,
 772                                                 branch_top->buf, head);
 773                         }
 774                         /*
 775                          * otherwise, the next "git fetch" will
 776                          * simply fetch from HEAD without updating
 777                          * any remote-tracking branch, which is what
 778                          * we want.
 779                          */
 780                 } else {
 781                         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top->buf);
 782                 }
 783                 /* Configure the remote */
 784                 if (value.len) {
 785                         strbuf_addf(&key, "remote.%s.fetch", option_origin);
 786                         git_config_set_multivar(key.buf, value.buf, "^$", 0);
 787                         strbuf_reset(&key);
 788
 789                         if (option_mirror) {
 790                                 strbuf_addf(&key, "remote.%s.mirror", option_origin);
 791                                 git_config_set(key.buf, "true");
 792                                 strbuf_reset(&key);
 793                         }
 794                 }
 795         }
 796
 797         strbuf_release(&key);
 798         strbuf_release(&value);
 799 }
 800
 801 static void dissociate_from_references(void)
 802 {
 803         static const char* argv[] = { "repack", "-a", "-d", NULL };
 804
 805         if (run_command_v_opt(argv, RUN_GIT_CMD|RUN_COMMAND_NO_STDIN))
 806                 die(_("cannot repack to clean up"));
 807         if (unlink(git_path("objects/info/alternates")) && errno != ENOENT)
 808                 die_errno(_("cannot unlink temporary alternates file"));
 809 }
 810
 811 int cmd_clone(int argc, const char **argv, const char *prefix)
 812 {
 813         int is_bundle = 0, is_local;
 814         struct stat buf;
 815         const char *repo_name, *repo, *work_tree, *git_dir;
 816         char *path, *dir;
 817         int dest_exists;
 818         const struct ref *refs, *remote_head;
 819         const struct ref *remote_head_points_at;
 820         const struct ref *our_head_points_at;
 821         struct ref *mapped_refs;
 822         const struct ref *ref;
 823         struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
 824         struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
 825         struct transport *transport = NULL;
 826         const char *src_ref_prefix = "refs/heads/";
 827         struct remote *remote;
 828         int err = 0, complete_refs_before_fetch = 1;
 829
 830         struct refspec *refspec;
 831         const char *fetch_pattern;
 832
 833         packet_trace_identity("clone");
 834         argc = parse_options(argc, argv, prefix, builtin_clone_options,
 835                              builtin_clone_usage, 0);
 836
 837         if (argc > 2)
 838                 usage_msg_opt(_("Too many arguments."),
 839                         builtin_clone_usage, builtin_clone_options);
 840
 841         if (argc == 0)
 842                 usage_msg_opt(_("You must specify a repository to clone."),
 843                         builtin_clone_usage, builtin_clone_options);
 844
 845         if (option_single_branch == -1)
 846                 option_single_branch = option_depth ? 1 : 0;
 847
 848         if (option_mirror)
 849                 option_bare = 1;
 850
 851         if (option_bare) {
 852                 if (option_origin)
 853                         die(_("--bare and --origin %s options are incompatible."),
 854                             option_origin);
 855                 if (real_git_dir)
 856                         die(_("--bare and --separate-git-dir are incompatible."));
 857                 option_no_checkout = 1;
 858         }
 859
 860         if (!option_origin)
 861                 option_origin = "origin";
 862
 863         repo_name = argv[0];
 864
 865         path = get_repo_path(repo_name, &is_bundle);
 866         if (path)
 867                 repo = xstrdup(absolute_path(repo_name));
 868         else if (!strchr(repo_name, ':'))
 869                 die(_("repository '%s' does not exist"), repo_name);
 870         else
 871                 repo = repo_name;
 872
 873         /* no need to be strict, transport_set_option() will validate it again */
 874         if (option_depth && atoi(option_depth) < 1)
 875                 die(_("depth %s is not a positive number"), option_depth);
 876
 877         if (argc == 2)
 878                 dir = xstrdup(argv[1]);
 879         else
 880                 dir = guess_dir_name(repo_name, is_bundle, option_bare);
 881         strip_trailing_slashes(dir);
 882
 883         dest_exists = !stat(dir, &buf);
 884         if (dest_exists && !is_empty_dir(dir))
 885                 die(_("destination path '%s' already exists and is not "
 886                         "an empty directory."), dir);
 887
 888         strbuf_addf(&reflog_msg, "clone: from %s", repo);
 889
 890         if (option_bare)
 891                 work_tree = NULL;
 892         else {
 893                 work_tree = getenv("GIT_WORK_TREE");
 894                 if (work_tree && !stat(work_tree, &buf))
 895                         die(_("working tree '%s' already exists."), work_tree);
 896         }
 897
 898         if (option_bare || work_tree)
 899                 git_dir = xstrdup(dir);
 900         else {
 901                 work_tree = dir;
 902                 git_dir = mkpathdup("%s/.git", dir);
 903         }
 904
 905         atexit(remove_junk);
 906         sigchain_push_common(remove_junk_on_signal);
 907
 908         if (!option_bare) {
 909                 if (safe_create_leading_directories_const(work_tree) < 0)
 910                         die_errno(_("could not create leading directories of '%s'"),
 911                                   work_tree);
 912                 if (!dest_exists && mkdir(work_tree, 0777))
 913                         die_errno(_("could not create work tree dir '%s'"),
 914                                   work_tree);
 915                 junk_work_tree = work_tree;
 916                 set_git_work_tree(work_tree);
 917         }
 918
 919         junk_git_dir = git_dir;
 920         if (safe_create_leading_directories_const(git_dir) < 0)
 921                 die(_("could not create leading directories of '%s'"), git_dir);
 922
 923         set_git_dir_init(git_dir, real_git_dir, 0);
 924         if (real_git_dir) {
 925                 git_dir = real_git_dir;
 926                 junk_git_dir = real_git_dir;
 927         }
 928
 929         if (0 <= option_verbosity) {
 930                 if (option_bare)
 931                         fprintf(stderr, _("Cloning into bare repository '%s'...\n"), dir);
 932                 else
 933                         fprintf(stderr, _("Cloning into '%s'...\n"), dir);
 934         }
 935         init_db(option_template, INIT_DB_QUIET);
 936         write_config(&option_config);
 937
 938         git_config(git_default_config, NULL);
 939
 940         if (option_bare) {
 941                 if (option_mirror)
 942                         src_ref_prefix = "refs/";
 943                 strbuf_addstr(&branch_top, src_ref_prefix);
 944
 945                 git_config_set("core.bare", "true");
 946         } else {
 947                 strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
 948         }
 949
 950         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
 951         strbuf_addf(&key, "remote.%s.url", option_origin);
 952         git_config_set(key.buf, repo);
 953         strbuf_reset(&key);
 954
 955         if (option_reference.nr)
 956                 setup_reference();
 957         else if (option_dissociate) {
 958                 warning(_("--dissociate given, but there is no --reference"));
 959                 option_dissociate = 0;
 960         }
 961
 962         fetch_pattern = value.buf;
 963         refspec = parse_fetch_refspec(1, &fetch_pattern);
 964
 965         strbuf_reset(&value);
 966
 967         remote = remote_get(option_origin);
 968         transport = transport_get(remote, remote->url[0]);
 969         transport_set_verbosity(transport, option_verbosity, option_progress);
 970
 971         path = get_repo_path(remote->url[0], &is_bundle);
 972         is_local = option_local != 0 && path && !is_bundle;
 973         if (is_local) {
 974                 if (option_depth)
 975                         warning(_("--depth is ignored in local clones; use file:// instead."));
 976                 if (!access(mkpath("%s/shallow", path), F_OK)) {
 977                         if (option_local > 0)
 978                                 warning(_("source repository is shallow, ignoring --local"));
 979                         is_local = 0;
 980                 }
 981         }
 982         if (option_local > 0 && !is_local)
 983                 warning(_("--local is ignored"));
 984         transport->cloning = 1;
 985
 986         if (!transport->get_refs_list || (!is_local && !transport->fetch))
 987                 die(_("Don't know how to clone %s"), transport->url);
 988
 989         transport_set_option(transport, TRANS_OPT_KEEP, "yes");
 990
 991         if (option_depth)
 992                 transport_set_option(transport, TRANS_OPT_DEPTH,
 993                                      option_depth);
 994         if (option_single_branch)
 995                 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
 996
 997         if (option_upload_pack)
 998                 transport_set_option(transport, TRANS_OPT_UPLOADPACK,
 999                                      option_upload_pack);
1000
1001         if (transport->smart_options && !option_depth)
1002                 transport->smart_options->check_self_contained_and_connected = 1;
1003
1004         refs = transport_get_remote_refs(transport);
1005
1006         if (refs) {
1007                 mapped_refs = wanted_peer_refs(refs, refspec);
1008                 /*
1009                  * transport_get_remote_refs() may return refs with null sha-1
1010                  * in mapped_refs (see struct transport->get_refs_list
1011                  * comment). In that case we need fetch it early because
1012                  * remote_head code below relies on it.
1013                  *
1014                  * for normal clones, transport_get_remote_refs() should
1015                  * return reliable ref set, we can delay cloning until after
1016                  * remote HEAD check.
1017                  */
1018                 for (ref = refs; ref; ref = ref->next)
1019                         if (is_null_sha1(ref->old_sha1)) {
1020                                 complete_refs_before_fetch = 0;
1021                                 break;
1022                         }
1023
1024                 if (!is_local && !complete_refs_before_fetch)
1025                         transport_fetch_refs(transport, mapped_refs);
1026
1027                 remote_head = find_ref_by_name(refs, "HEAD");
1028                 remote_head_points_at =
1029                         guess_remote_head(remote_head, mapped_refs, 0);
1030
1031                 if (option_branch) {
1032                         our_head_points_at =
1033                                 find_remote_branch(mapped_refs, option_branch);
1034
1035                         if (!our_head_points_at)
1036                                 die(_("Remote branch %s not found in upstream %s"),
1037                                     option_branch, option_origin);
1038                 }
1039                 else
1040                         our_head_points_at = remote_head_points_at;
1041         }
1042         else {
1043                 if (option_branch)
1044                         die(_("Remote branch %s not found in upstream %s"),
1045                                         option_branch, option_origin);
1046
1047                 warning(_("You appear to have cloned an empty repository."));
1048                 mapped_refs = NULL;
1049                 our_head_points_at = NULL;
1050                 remote_head_points_at = NULL;
1051                 remote_head = NULL;
1052                 option_no_checkout = 1;
1053                 if (!option_bare)
1054                         install_branch_config(0, "master", option_origin,
1055                                               "refs/heads/master");
1056         }
1057
1058         write_refspec_config(src_ref_prefix, our_head_points_at,
1059                         remote_head_points_at, &branch_top);
1060
1061         if (is_local)
1062                 clone_local(path, git_dir);
1063         else if (refs && complete_refs_before_fetch)
1064                 transport_fetch_refs(transport, mapped_refs);
1065
1066         update_remote_refs(refs, mapped_refs, remote_head_points_at,
1067                            branch_top.buf, reflog_msg.buf, transport, !is_local);
1068
1069         update_head(our_head_points_at, remote_head, reflog_msg.buf);
1070
1071         transport_unlock_pack(transport);
1072         transport_disconnect(transport);
1073
1074         if (option_dissociate) {
1075                 close_all_packs();
1076                 dissociate_from_references();
1077         }
1078
1079         junk_mode = JUNK_LEAVE_REPO;
1080         err = checkout();
1081
1082         strbuf_release(&reflog_msg);
1083         strbuf_release(&branch_top);
1084         strbuf_release(&key);
1085         strbuf_release(&value);
1086         junk_mode = JUNK_LEAVE_ALL;
1087
1088         free(refspec);
1089         return err;
1090 }