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 int opt_parse_reference(const struct option *opt, const char *arg, int unset)
  55 {
  56         struct string_list *option_reference = opt->value;
  57         if (!arg)
  58                 return -1;
  59         string_list_append(option_reference, arg);
  60         return 0;
  61 }
  62
  63 static struct option builtin_clone_options[] = {
  64         OPT__VERBOSITY(&option_verbosity),
  65         OPT_BOOL(0, "progress", &option_progress,
  66                  N_("force progress reporting")),
  67         OPT_BOOL('n', "no-checkout", &option_no_checkout,
  68                  N_("don't create a checkout")),
  69         OPT_BOOL(0, "bare", &option_bare, N_("create a bare repository")),
  70         OPT_HIDDEN_BOOL(0, "naked", &option_bare,
  71                         N_("create a bare repository")),
  72         OPT_BOOL(0, "mirror", &option_mirror,
  73                  N_("create a mirror repository (implies bare)")),
  74         OPT_BOOL('l', "local", &option_local,
  75                 N_("to clone from a local repository")),
  76         OPT_BOOL(0, "no-hardlinks", &option_no_hardlinks,
  77                     N_("don't use local hardlinks, always copy")),
  78         OPT_BOOL('s', "shared", &option_shared,
  79                     N_("setup as shared repository")),
  80         OPT_BOOL(0, "recursive", &option_recursive,
  81                     N_("initialize submodules in the clone")),
  82         OPT_BOOL(0, "recurse-submodules", &option_recursive,
  83                     N_("initialize submodules in the clone")),
  84         OPT_STRING(0, "template", &option_template, N_("template-directory"),
  85                    N_("directory from which templates will be used")),
  86         OPT_CALLBACK(0 , "reference", &option_reference, N_("repo"),
  87                      N_("reference repository"), &opt_parse_reference),
  88         OPT_STRING('o', "origin", &option_origin, N_("name"),
  89                    N_("use <name> instead of 'origin' to track upstream")),
  90         OPT_STRING('b', "branch", &option_branch, N_("branch"),
  91                    N_("checkout <branch> instead of the remote's HEAD")),
  92         OPT_STRING('u', "upload-pack", &option_upload_pack, N_("path"),
  93                    N_("path to git-upload-pack on the remote")),
  94         OPT_STRING(0, "depth", &option_depth, N_("depth"),
  95                     N_("create a shallow clone of that depth")),
  96         OPT_BOOL(0, "single-branch", &option_single_branch,
  97                     N_("clone only one branch, HEAD or --branch")),
  98         OPT_BOOL(0, "dissociate", &option_dissociate,
  99                  N_("use --reference only while cloning")),
 100         OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
 101                    N_("separate git dir from working tree")),
 102         OPT_STRING_LIST('c', "config", &option_config, N_("key=value"),
 103                         N_("set config inside the new repository")),
 104         OPT_END()
 105 };
 106
 107 static const char *argv_submodule[] = {
 108         "submodule", "update", "--init", "--recursive", NULL
 109 };
 110
 111 static char *get_repo_path(const char *repo, int *is_bundle)
 112 {
 113         static char *suffix[] = { "/.git", "", ".git/.git", ".git" };
 114         static char *bundle_suffix[] = { ".bundle", "" };
 115         struct stat st;
 116         int i;
 117
 118         for (i = 0; i < ARRAY_SIZE(suffix); i++) {
 119                 const char *path;
 120                 path = mkpath("%s%s", repo, suffix[i]);
 121                 if (stat(path, &st))
 122                         continue;
 123                 if (S_ISDIR(st.st_mode) && is_git_directory(path)) {
 124                         *is_bundle = 0;
 125                         return xstrdup(absolute_path(path));
 126                 } else if (S_ISREG(st.st_mode) && st.st_size > 8) {
 127                         /* Is it a "gitfile"? */
 128                         char signature[8];
 129                         int len, fd = open(path, O_RDONLY);
 130                         if (fd < 0)
 131                                 continue;
 132                         len = read_in_full(fd, signature, 8);
 133                         close(fd);
 134                         if (len != 8 || strncmp(signature, "gitdir: ", 8))
 135                                 continue;
 136                         path = read_gitfile(path);
 137                         if (path) {
 138                                 *is_bundle = 0;
 139                                 return xstrdup(absolute_path(path));
 140                         }
 141                 }
 142         }
 143
 144         for (i = 0; i < ARRAY_SIZE(bundle_suffix); i++) {
 145                 const char *path;
 146                 path = mkpath("%s%s", repo, bundle_suffix[i]);
 147                 if (!stat(path, &st) && S_ISREG(st.st_mode)) {
 148                         *is_bundle = 1;
 149                         return xstrdup(absolute_path(path));
 150                 }
 151         }
 152
 153         return NULL;
 154 }
 155
 156 static char *guess_dir_name(const char *repo, int is_bundle, int is_bare)
 157 {
 158         const char *end = repo + strlen(repo), *start;
 159         char *dir;
 160
 161         /*
 162          * Strip trailing spaces, slashes and /.git
 163          */
 164         while (repo < end && (is_dir_sep(end[-1]) || isspace(end[-1])))
 165                 end--;
 166         if (end - repo > 5 && is_dir_sep(end[-5]) &&
 167             !strncmp(end - 4, ".git", 4)) {
 168                 end -= 5;
 169                 while (repo < end && is_dir_sep(end[-1]))
 170                         end--;
 171         }
 172
 173         /*
 174          * Find last component, but be prepared that repo could have
 175          * the form  "remote.example.com:foo.git", i.e. no slash
 176          * in the directory part.
 177          */
 178         start = end;
 179         while (repo < start && !is_dir_sep(start[-1]) && start[-1] != ':')
 180                 start--;
 181
 182         /*
 183          * Strip .{bundle,git}.
 184          */
 185         if (is_bundle) {
 186                 if (end - start > 7 && !strncmp(end - 7, ".bundle", 7))
 187                         end -= 7;
 188         } else {
 189                 if (end - start > 4 && !strncmp(end - 4, ".git", 4))
 190                         end -= 4;
 191         }
 192
 193         if (is_bare) {
 194                 struct strbuf result = STRBUF_INIT;
 195                 strbuf_addf(&result, "%.*s.git", (int)(end - start), start);
 196                 dir = strbuf_detach(&result, NULL);
 197         } else
 198                 dir = xstrndup(start, end - start);
 199         /*
 200          * Replace sequences of 'control' characters and whitespace
 201          * with one ascii space, remove leading and trailing spaces.
 202          */
 203         if (*dir) {
 204                 char *out = dir;
 205                 int prev_space = 1 /* strip leading whitespace */;
 206                 for (end = dir; *end; ++end) {
 207                         char ch = *end;
 208                         if ((unsigned char)ch < '\x20')
 209                                 ch = '\x20';
 210                         if (isspace(ch)) {
 211                                 if (prev_space)
 212                                         continue;
 213                                 prev_space = 1;
 214                         } else
 215                                 prev_space = 0;
 216                         *out++ = ch;
 217                 }
 218                 *out = '\0';
 219                 if (out > dir && prev_space)
 220                         out[-1] = '\0';
 221         }
 222         return dir;
 223 }
 224
 225 static void strip_trailing_slashes(char *dir)
 226 {
 227         char *end = dir + strlen(dir);
 228
 229         while (dir < end - 1 && is_dir_sep(end[-1]))
 230                 end--;
 231         *end = '\0';
 232 }
 233
 234 static int add_one_reference(struct string_list_item *item, void *cb_data)
 235 {
 236         char *ref_git;
 237         const char *repo;
 238         struct strbuf alternate = STRBUF_INIT;
 239
 240         /* Beware: read_gitfile(), real_path() and mkpath() return static buffer */
 241         ref_git = xstrdup(real_path(item->string));
 242
 243         repo = read_gitfile(ref_git);
 244         if (!repo)
 245                 repo = read_gitfile(mkpath("%s/.git", ref_git));
 246         if (repo) {
 247                 free(ref_git);
 248                 ref_git = xstrdup(repo);
 249         }
 250
 251         if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
 252                 char *ref_git_git = mkpathdup("%s/.git", ref_git);
 253                 free(ref_git);
 254                 ref_git = ref_git_git;
 255         } else if (!is_directory(mkpath("%s/objects", ref_git)))
 256                 die(_("reference repository '%s' is not a local repository."),
 257                     item->string);
 258
 259         if (!access(mkpath("%s/shallow", ref_git), F_OK))
 260                 die(_("reference repository '%s' is shallow"), item->string);
 261
 262         if (!access(mkpath("%s/info/grafts", ref_git), F_OK))
 263                 die(_("reference repository '%s' is grafted"), item->string);
 264
 265         strbuf_addf(&alternate, "%s/objects", ref_git);
 266         add_to_alternates_file(alternate.buf);
 267         strbuf_release(&alternate);
 268         free(ref_git);
 269         return 0;
 270 }
 271
 272 static void setup_reference(void)
 273 {
 274         for_each_string_list(&option_reference, add_one_reference, NULL);
 275 }
 276
 277 static void copy_alternates(struct strbuf *src, struct strbuf *dst,
 278                             const char *src_repo)
 279 {
 280         /*
 281          * Read from the source objects/info/alternates file
 282          * and copy the entries to corresponding file in the
 283          * destination repository with add_to_alternates_file().
 284          * Both src and dst have "$path/objects/info/alternates".
 285          *
 286          * Instead of copying bit-for-bit from the original,
 287          * we need to append to existing one so that the already
 288          * created entry via "clone -s" is not lost, and also
 289          * to turn entries with paths relative to the original
 290          * absolute, so that they can be used in the new repository.
 291          */
 292         FILE *in = fopen(src->buf, "r");
 293         struct strbuf line = STRBUF_INIT;
 294
 295         while (strbuf_getline(&line, in, '\n') != EOF) {
 296                 char *abs_path, abs_buf[PATH_MAX];
 297                 if (!line.len || line.buf[0] == '#')
 298                         continue;
 299                 if (is_absolute_path(line.buf)) {
 300                         add_to_alternates_file(line.buf);
 301                         continue;
 302                 }
 303                 abs_path = mkpath("%s/objects/%s", src_repo, line.buf);
 304                 normalize_path_copy(abs_buf, abs_path);
 305                 add_to_alternates_file(abs_buf);
 306         }
 307         strbuf_release(&line);
 308         fclose(in);
 309 }
 310
 311 static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
 312                                    const char *src_repo, int src_baselen)
 313 {
 314         struct dirent *de;
 315         struct stat buf;
 316         int src_len, dest_len;
 317         DIR *dir;
 318
 319         dir = opendir(src->buf);
 320         if (!dir)
 321                 die_errno(_("failed to open '%s'"), src->buf);
 322
 323         if (mkdir(dest->buf, 0777)) {
 324                 if (errno != EEXIST)
 325                         die_errno(_("failed to create directory '%s'"), dest->buf);
 326                 else if (stat(dest->buf, &buf))
 327                         die_errno(_("failed to stat '%s'"), dest->buf);
 328                 else if (!S_ISDIR(buf.st_mode))
 329                         die(_("%s exists and is not a directory"), dest->buf);
 330         }
 331
 332         strbuf_addch(src, '/');
 333         src_len = src->len;
 334         strbuf_addch(dest, '/');
 335         dest_len = dest->len;
 336
 337         while ((de = readdir(dir)) != NULL) {
 338                 strbuf_setlen(src, src_len);
 339                 strbuf_addstr(src, de->d_name);
 340                 strbuf_setlen(dest, dest_len);
 341                 strbuf_addstr(dest, de->d_name);
 342                 if (stat(src->buf, &buf)) {
 343                         warning (_("failed to stat %s\n"), src->buf);
 344                         continue;
 345                 }
 346                 if (S_ISDIR(buf.st_mode)) {
 347                         if (de->d_name[0] != '.')
 348                                 copy_or_link_directory(src, dest,
 349                                                        src_repo, src_baselen);
 350                         continue;
 351                 }
 352
 353                 /* Files that cannot be copied bit-for-bit... */
 354                 if (!strcmp(src->buf + src_baselen, "/info/alternates")) {
 355                         copy_alternates(src, dest, src_repo);
 356                         continue;
 357                 }
 358
 359                 if (unlink(dest->buf) && errno != ENOENT)
 360                         die_errno(_("failed to unlink '%s'"), dest->buf);
 361                 if (!option_no_hardlinks) {
 362                         if (!link(src->buf, dest->buf))
 363                                 continue;
 364                         if (option_local > 0)
 365                                 die_errno(_("failed to create link '%s'"), dest->buf);
 366                         option_no_hardlinks = 1;
 367                 }
 368                 if (copy_file_with_time(dest->buf, src->buf, 0666))
 369                         die_errno(_("failed to copy file to '%s'"), dest->buf);
 370         }
 371         closedir(dir);
 372 }
 373
 374 static void clone_local(const char *src_repo, const char *dest_repo)
 375 {
 376         if (option_shared) {
 377                 struct strbuf alt = STRBUF_INIT;
 378                 strbuf_addf(&alt, "%s/objects", src_repo);
 379                 add_to_alternates_file(alt.buf);
 380                 strbuf_release(&alt);
 381         } else {
 382                 struct strbuf src = STRBUF_INIT;
 383                 struct strbuf dest = STRBUF_INIT;
 384                 strbuf_addf(&src, "%s/objects", src_repo);
 385                 strbuf_addf(&dest, "%s/objects", dest_repo);
 386                 copy_or_link_directory(&src, &dest, src_repo, src.len);
 387                 strbuf_release(&src);
 388                 strbuf_release(&dest);
 389         }
 390
 391         if (0 <= option_verbosity)
 392                 fprintf(stderr, _("done.\n"));
 393 }
 394
 395 static const char *junk_work_tree;
 396 static const char *junk_git_dir;
 397 static enum {
 398         JUNK_LEAVE_NONE,
 399         JUNK_LEAVE_REPO,
 400         JUNK_LEAVE_ALL
 401 } junk_mode = JUNK_LEAVE_NONE;
 402
 403 static const char junk_leave_repo_msg[] =
 404 N_("Clone succeeded, but checkout failed.\n"
 405    "You can inspect what was checked out with 'git status'\n"
 406    "and retry the checkout with 'git checkout -f HEAD'\n");
 407
 408 static void remove_junk(void)
 409 {
 410         struct strbuf sb = STRBUF_INIT;
 411
 412         switch (junk_mode) {
 413         case JUNK_LEAVE_REPO:
 414                 warning("%s", _(junk_leave_repo_msg));
 415                 /* fall-through */
 416         case JUNK_LEAVE_ALL:
 417                 return;
 418         default:
 419                 /* proceed to removal */
 420                 break;
 421         }
 422
 423         if (junk_git_dir) {
 424                 strbuf_addstr(&sb, junk_git_dir);
 425                 remove_dir_recursively(&sb, 0);
 426                 strbuf_reset(&sb);
 427         }
 428         if (junk_work_tree) {
 429                 strbuf_addstr(&sb, junk_work_tree);
 430                 remove_dir_recursively(&sb, 0);
 431                 strbuf_reset(&sb);
 432         }
 433 }
 434
 435 static void remove_junk_on_signal(int signo)
 436 {
 437         remove_junk();
 438         sigchain_pop(signo);
 439         raise(signo);
 440 }
 441
 442 static struct ref *find_remote_branch(const struct ref *refs, const char *branch)
 443 {
 444         struct ref *ref;
 445         struct strbuf head = STRBUF_INIT;
 446         strbuf_addstr(&head, "refs/heads/");
 447         strbuf_addstr(&head, branch);
 448         ref = find_ref_by_name(refs, head.buf);
 449         strbuf_release(&head);
 450
 451         if (ref)
 452                 return ref;
 453
 454         strbuf_addstr(&head, "refs/tags/");
 455         strbuf_addstr(&head, branch);
 456         ref = find_ref_by_name(refs, head.buf);
 457         strbuf_release(&head);
 458
 459         return ref;
 460 }
 461
 462 static struct ref *wanted_peer_refs(const struct ref *refs,
 463                 struct refspec *refspec)
 464 {
 465         struct ref *head = copy_ref(find_ref_by_name(refs, "HEAD"));
 466         struct ref *local_refs = head;
 467         struct ref **tail = head ? &head->next : &local_refs;
 468
 469         if (option_single_branch) {
 470                 struct ref *remote_head = NULL;
 471
 472                 if (!option_branch)
 473                         remote_head = guess_remote_head(head, refs, 0);
 474                 else {
 475                         local_refs = NULL;
 476                         tail = &local_refs;
 477                         remote_head = copy_ref(find_remote_branch(refs, option_branch));
 478                 }
 479
 480                 if (!remote_head && option_branch)
 481                         warning(_("Could not find remote branch %s to clone."),
 482                                 option_branch);
 483                 else {
 484                         get_fetch_map(remote_head, refspec, &tail, 0);
 485
 486                         /* if --branch=tag, pull the requested tag explicitly */
 487                         get_fetch_map(remote_head, tag_refspec, &tail, 0);
 488                 }
 489         } else
 490                 get_fetch_map(refs, refspec, &tail, 0);
 491
 492         if (!option_mirror && !option_single_branch)
 493                 get_fetch_map(refs, tag_refspec, &tail, 0);
 494
 495         return local_refs;
 496 }
 497
 498 static void write_remote_refs(const struct ref *local_refs)
 499 {
 500         const struct ref *r;
 501
 502         lock_packed_refs(LOCK_DIE_ON_ERROR);
 503
 504         for (r = local_refs; r; r = r->next) {
 505                 if (!r->peer_ref)
 506                         continue;
 507                 add_packed_ref(r->peer_ref->name, r->old_sha1);
 508         }
 509
 510         if (commit_packed_refs())
 511                 die_errno("unable to overwrite old ref-pack file");
 512 }
 513
 514 static void write_followtags(const struct ref *refs, const char *msg)
 515 {
 516         const struct ref *ref;
 517         for (ref = refs; ref; ref = ref->next) {
 518                 if (!starts_with(ref->name, "refs/tags/"))
 519                         continue;
 520                 if (ends_with(ref->name, "^{}"))
 521                         continue;
 522                 if (!has_sha1_file(ref->old_sha1))
 523                         continue;
 524                 update_ref(msg, ref->name, ref->old_sha1,
 525                            NULL, 0, UPDATE_REFS_DIE_ON_ERR);
 526         }
 527 }
 528
 529 static int iterate_ref_map(void *cb_data, unsigned char sha1[20])
 530 {
 531         struct ref **rm = cb_data;
 532         struct ref *ref = *rm;
 533
 534         /*
 535          * Skip anything missing a peer_ref, which we are not
 536          * actually going to write a ref for.
 537          */
 538         while (ref && !ref->peer_ref)
 539                 ref = ref->next;
 540         /* Returning -1 notes "end of list" to the caller. */
 541         if (!ref)
 542                 return -1;
 543
 544         hashcpy(sha1, ref->old_sha1);
 545         *rm = ref->next;
 546         return 0;
 547 }
 548
 549 static void update_remote_refs(const struct ref *refs,
 550                                const struct ref *mapped_refs,
 551                                const struct ref *remote_head_points_at,
 552                                const char *branch_top,
 553                                const char *msg,
 554                                struct transport *transport,
 555                                int check_connectivity)
 556 {
 557         const struct ref *rm = mapped_refs;
 558
 559         if (check_connectivity) {
 560                 if (transport->progress)
 561                         fprintf(stderr, _("Checking connectivity... "));
 562                 if (check_everything_connected_with_transport(iterate_ref_map,
 563                                                               0, &rm, transport))
 564                         die(_("remote did not send all necessary objects"));
 565                 if (transport->progress)
 566                         fprintf(stderr, _("done.\n"));
 567         }
 568
 569         if (refs) {
 570                 write_remote_refs(mapped_refs);
 571                 if (option_single_branch)
 572                         write_followtags(refs, msg);
 573         }
 574
 575         if (remote_head_points_at && !option_bare) {
 576                 struct strbuf head_ref = STRBUF_INIT;
 577                 strbuf_addstr(&head_ref, branch_top);
 578                 strbuf_addstr(&head_ref, "HEAD");
 579                 create_symref(head_ref.buf,
 580                               remote_head_points_at->peer_ref->name,
 581                               msg);
 582         }
 583 }
 584
 585 static void update_head(const struct ref *our, const struct ref *remote,
 586                         const char *msg)
 587 {
 588         const char *head;
 589         if (our && skip_prefix(our->name, "refs/heads/", &head)) {
 590                 /* Local default branch link */
 591                 create_symref("HEAD", our->name, NULL);
 592                 if (!option_bare) {
 593                         update_ref(msg, "HEAD", our->old_sha1, NULL, 0,
 594                                    UPDATE_REFS_DIE_ON_ERR);
 595                         install_branch_config(0, head, option_origin, our->name);
 596                 }
 597         } else if (our) {
 598                 struct commit *c = lookup_commit_reference(our->old_sha1);
 599                 /* --branch specifies a non-branch (i.e. tags), detach HEAD */
 600                 update_ref(msg, "HEAD", c->object.sha1,
 601                            NULL, REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
 602         } else if (remote) {
 603                 /*
 604                  * We know remote HEAD points to a non-branch, or
 605                  * HEAD points to a branch but we don't know which one.
 606                  * Detach HEAD in all these cases.
 607                  */
 608                 update_ref(msg, "HEAD", remote->old_sha1,
 609                            NULL, REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
 610         }
 611 }
 612
 613 static int checkout(void)
 614 {
 615         unsigned char sha1[20];
 616         char *head;
 617         struct lock_file *lock_file;
 618         struct unpack_trees_options opts;
 619         struct tree *tree;
 620         struct tree_desc t;
 621         int err = 0;
 622
 623         if (option_no_checkout)
 624                 return 0;
 625
 626         head = resolve_refdup("HEAD", RESOLVE_REF_READING, sha1, NULL);
 627         if (!head) {
 628                 warning(_("remote HEAD refers to nonexistent ref, "
 629                           "unable to checkout.\n"));
 630                 return 0;
 631         }
 632         if (!strcmp(head, "HEAD")) {
 633                 if (advice_detached_head)
 634                         detach_advice(sha1_to_hex(sha1));
 635         } else {
 636                 if (!starts_with(head, "refs/heads/"))
 637                         die(_("HEAD not found below refs/heads!"));
 638         }
 639         free(head);
 640
 641         /* We need to be in the new work tree for the checkout */
 642         setup_work_tree();
 643
 644         lock_file = xcalloc(1, sizeof(struct lock_file));
 645         hold_locked_index(lock_file, 1);
 646
 647         memset(&opts, 0, sizeof opts);
 648         opts.update = 1;
 649         opts.merge = 1;
 650         opts.fn = oneway_merge;
 651         opts.verbose_update = (option_verbosity >= 0);
 652         opts.src_index = &the_index;
 653         opts.dst_index = &the_index;
 654
 655         tree = parse_tree_indirect(sha1);
 656         parse_tree(tree);
 657         init_tree_desc(&t, tree->buffer, tree->size);
 658         if (unpack_trees(1, &t, &opts) < 0)
 659                 die(_("unable to checkout working tree"));
 660
 661         if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
 662                 die(_("unable to write new index file"));
 663
 664         err |= run_hook_le(NULL, "post-checkout", sha1_to_hex(null_sha1),
 665                            sha1_to_hex(sha1), "1", NULL);
 666
 667         if (!err && option_recursive)
 668                 err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
 669
 670         return err;
 671 }
 672
 673 static int write_one_config(const char *key, const char *value, void *data)
 674 {
 675         return git_config_set_multivar(key, value ? value : "true", "^$", 0);
 676 }
 677
 678 static void write_config(struct string_list *config)
 679 {
 680         int i;
 681
 682         for (i = 0; i < config->nr; i++) {
 683                 if (git_config_parse_parameter(config->items[i].string,
 684                                                write_one_config, NULL) < 0)
 685                         die("unable to write parameters to config file");
 686         }
 687 }
 688
 689 static void write_refspec_config(const char *src_ref_prefix,
 690                 const struct ref *our_head_points_at,
 691                 const struct ref *remote_head_points_at,
 692                 struct strbuf *branch_top)
 693 {
 694         struct strbuf key = STRBUF_INIT;
 695         struct strbuf value = STRBUF_INIT;
 696
 697         if (option_mirror || !option_bare) {
 698                 if (option_single_branch && !option_mirror) {
 699                         if (option_branch) {
 700                                 if (starts_with(our_head_points_at->name, "refs/tags/"))
 701                                         strbuf_addf(&value, "+%s:%s", our_head_points_at->name,
 702                                                 our_head_points_at->name);
 703                                 else
 704                                         strbuf_addf(&value, "+%s:%s%s", our_head_points_at->name,
 705                                                 branch_top->buf, option_branch);
 706                         } else if (remote_head_points_at) {
 707                                 const char *head = remote_head_points_at->name;
 708                                 if (!skip_prefix(head, "refs/heads/", &head))
 709                                         die("BUG: remote HEAD points at non-head?");
 710
 711                                 strbuf_addf(&value, "+%s:%s%s", remote_head_points_at->name,
 712                                                 branch_top->buf, head);
 713                         }
 714                         /*
 715                          * otherwise, the next "git fetch" will
 716                          * simply fetch from HEAD without updating
 717                          * any remote-tracking branch, which is what
 718                          * we want.
 719                          */
 720                 } else {
 721                         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top->buf);
 722                 }
 723                 /* Configure the remote */
 724                 if (value.len) {
 725                         strbuf_addf(&key, "remote.%s.fetch", option_origin);
 726                         git_config_set_multivar(key.buf, value.buf, "^$", 0);
 727                         strbuf_reset(&key);
 728
 729                         if (option_mirror) {
 730                                 strbuf_addf(&key, "remote.%s.mirror", option_origin);
 731                                 git_config_set(key.buf, "true");
 732                                 strbuf_reset(&key);
 733                         }
 734                 }
 735         }
 736
 737         strbuf_release(&key);
 738         strbuf_release(&value);
 739 }
 740
 741 static void dissociate_from_references(void)
 742 {
 743         static const char* argv[] = { "repack", "-a", "-d", NULL };
 744
 745         if (run_command_v_opt(argv, RUN_GIT_CMD|RUN_COMMAND_NO_STDIN))
 746                 die(_("cannot repack to clean up"));
 747         if (unlink(git_path("objects/info/alternates")) && errno != ENOENT)
 748                 die_errno(_("cannot unlink temporary alternates file"));
 749 }
 750
 751 int cmd_clone(int argc, const char **argv, const char *prefix)
 752 {
 753         int is_bundle = 0, is_local;
 754         struct stat buf;
 755         const char *repo_name, *repo, *work_tree, *git_dir;
 756         char *path, *dir;
 757         int dest_exists;
 758         const struct ref *refs, *remote_head;
 759         const struct ref *remote_head_points_at;
 760         const struct ref *our_head_points_at;
 761         struct ref *mapped_refs;
 762         const struct ref *ref;
 763         struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
 764         struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
 765         struct transport *transport = NULL;
 766         const char *src_ref_prefix = "refs/heads/";
 767         struct remote *remote;
 768         int err = 0, complete_refs_before_fetch = 1;
 769
 770         struct refspec *refspec;
 771         const char *fetch_pattern;
 772
 773         packet_trace_identity("clone");
 774         argc = parse_options(argc, argv, prefix, builtin_clone_options,
 775                              builtin_clone_usage, 0);
 776
 777         if (argc > 2)
 778                 usage_msg_opt(_("Too many arguments."),
 779                         builtin_clone_usage, builtin_clone_options);
 780
 781         if (argc == 0)
 782                 usage_msg_opt(_("You must specify a repository to clone."),
 783                         builtin_clone_usage, builtin_clone_options);
 784
 785         if (option_single_branch == -1)
 786                 option_single_branch = option_depth ? 1 : 0;
 787
 788         if (option_mirror)
 789                 option_bare = 1;
 790
 791         if (option_bare) {
 792                 if (option_origin)
 793                         die(_("--bare and --origin %s options are incompatible."),
 794                             option_origin);
 795                 if (real_git_dir)
 796                         die(_("--bare and --separate-git-dir are incompatible."));
 797                 option_no_checkout = 1;
 798         }
 799
 800         if (!option_origin)
 801                 option_origin = "origin";
 802
 803         repo_name = argv[0];
 804
 805         path = get_repo_path(repo_name, &is_bundle);
 806         if (path)
 807                 repo = xstrdup(absolute_path(repo_name));
 808         else if (!strchr(repo_name, ':'))
 809                 die(_("repository '%s' does not exist"), repo_name);
 810         else
 811                 repo = repo_name;
 812
 813         /* no need to be strict, transport_set_option() will validate it again */
 814         if (option_depth && atoi(option_depth) < 1)
 815                 die(_("depth %s is not a positive number"), option_depth);
 816
 817         if (argc == 2)
 818                 dir = xstrdup(argv[1]);
 819         else
 820                 dir = guess_dir_name(repo_name, is_bundle, option_bare);
 821         strip_trailing_slashes(dir);
 822
 823         dest_exists = !stat(dir, &buf);
 824         if (dest_exists && !is_empty_dir(dir))
 825                 die(_("destination path '%s' already exists and is not "
 826                         "an empty directory."), dir);
 827
 828         strbuf_addf(&reflog_msg, "clone: from %s", repo);
 829
 830         if (option_bare)
 831                 work_tree = NULL;
 832         else {
 833                 work_tree = getenv("GIT_WORK_TREE");
 834                 if (work_tree && !stat(work_tree, &buf))
 835                         die(_("working tree '%s' already exists."), work_tree);
 836         }
 837
 838         if (option_bare || work_tree)
 839                 git_dir = xstrdup(dir);
 840         else {
 841                 work_tree = dir;
 842                 git_dir = mkpathdup("%s/.git", dir);
 843         }
 844
 845         atexit(remove_junk);
 846         sigchain_push_common(remove_junk_on_signal);
 847
 848         if (!option_bare) {
 849                 if (safe_create_leading_directories_const(work_tree) < 0)
 850                         die_errno(_("could not create leading directories of '%s'"),
 851                                   work_tree);
 852                 if (!dest_exists && mkdir(work_tree, 0777))
 853                         die_errno(_("could not create work tree dir '%s'"),
 854                                   work_tree);
 855                 junk_work_tree = work_tree;
 856                 set_git_work_tree(work_tree);
 857         }
 858
 859         junk_git_dir = git_dir;
 860         if (safe_create_leading_directories_const(git_dir) < 0)
 861                 die(_("could not create leading directories of '%s'"), git_dir);
 862
 863         set_git_dir_init(git_dir, real_git_dir, 0);
 864         if (real_git_dir) {
 865                 git_dir = real_git_dir;
 866                 junk_git_dir = real_git_dir;
 867         }
 868
 869         if (0 <= option_verbosity) {
 870                 if (option_bare)
 871                         fprintf(stderr, _("Cloning into bare repository '%s'...\n"), dir);
 872                 else
 873                         fprintf(stderr, _("Cloning into '%s'...\n"), dir);
 874         }
 875         init_db(option_template, INIT_DB_QUIET);
 876         write_config(&option_config);
 877
 878         git_config(git_default_config, NULL);
 879
 880         if (option_bare) {
 881                 if (option_mirror)
 882                         src_ref_prefix = "refs/";
 883                 strbuf_addstr(&branch_top, src_ref_prefix);
 884
 885                 git_config_set("core.bare", "true");
 886         } else {
 887                 strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
 888         }
 889
 890         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
 891         strbuf_addf(&key, "remote.%s.url", option_origin);
 892         git_config_set(key.buf, repo);
 893         strbuf_reset(&key);
 894
 895         if (option_reference.nr)
 896                 setup_reference();
 897         else if (option_dissociate) {
 898                 warning(_("--dissociate given, but there is no --reference"));
 899                 option_dissociate = 0;
 900         }
 901
 902         fetch_pattern = value.buf;
 903         refspec = parse_fetch_refspec(1, &fetch_pattern);
 904
 905         strbuf_reset(&value);
 906
 907         remote = remote_get(option_origin);
 908         transport = transport_get(remote, remote->url[0]);
 909         path = get_repo_path(remote->url[0], &is_bundle);
 910         is_local = option_local != 0 && path && !is_bundle;
 911         if (is_local) {
 912                 if (option_depth)
 913                         warning(_("--depth is ignored in local clones; use file:// instead."));
 914                 if (!access(mkpath("%s/shallow", path), F_OK)) {
 915                         if (option_local > 0)
 916                                 warning(_("source repository is shallow, ignoring --local"));
 917                         is_local = 0;
 918                 }
 919         }
 920         if (option_local > 0 && !is_local)
 921                 warning(_("--local is ignored"));
 922         transport->cloning = 1;
 923
 924         if (!transport->get_refs_list || (!is_local && !transport->fetch))
 925                 die(_("Don't know how to clone %s"), transport->url);
 926
 927         transport_set_option(transport, TRANS_OPT_KEEP, "yes");
 928
 929         if (option_depth)
 930                 transport_set_option(transport, TRANS_OPT_DEPTH,
 931                                      option_depth);
 932         if (option_single_branch)
 933                 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
 934
 935         transport_set_verbosity(transport, option_verbosity, option_progress);
 936
 937         if (option_upload_pack)
 938                 transport_set_option(transport, TRANS_OPT_UPLOADPACK,
 939                                      option_upload_pack);
 940
 941         if (transport->smart_options && !option_depth)
 942                 transport->smart_options->check_self_contained_and_connected = 1;
 943
 944         refs = transport_get_remote_refs(transport);
 945
 946         if (refs) {
 947                 mapped_refs = wanted_peer_refs(refs, refspec);
 948                 /*
 949                  * transport_get_remote_refs() may return refs with null sha-1
 950                  * in mapped_refs (see struct transport->get_refs_list
 951                  * comment). In that case we need fetch it early because
 952                  * remote_head code below relies on it.
 953                  *
 954                  * for normal clones, transport_get_remote_refs() should
 955                  * return reliable ref set, we can delay cloning until after
 956                  * remote HEAD check.
 957                  */
 958                 for (ref = refs; ref; ref = ref->next)
 959                         if (is_null_sha1(ref->old_sha1)) {
 960                                 complete_refs_before_fetch = 0;
 961                                 break;
 962                         }
 963
 964                 if (!is_local && !complete_refs_before_fetch)
 965                         transport_fetch_refs(transport, mapped_refs);
 966
 967                 remote_head = find_ref_by_name(refs, "HEAD");
 968                 remote_head_points_at =
 969                         guess_remote_head(remote_head, mapped_refs, 0);
 970
 971                 if (option_branch) {
 972                         our_head_points_at =
 973                                 find_remote_branch(mapped_refs, option_branch);
 974
 975                         if (!our_head_points_at)
 976                                 die(_("Remote branch %s not found in upstream %s"),
 977                                     option_branch, option_origin);
 978                 }
 979                 else
 980                         our_head_points_at = remote_head_points_at;
 981         }
 982         else {
 983                 if (option_branch)
 984                         die(_("Remote branch %s not found in upstream %s"),
 985                                         option_branch, option_origin);
 986
 987                 warning(_("You appear to have cloned an empty repository."));
 988                 mapped_refs = NULL;
 989                 our_head_points_at = NULL;
 990                 remote_head_points_at = NULL;
 991                 remote_head = NULL;
 992                 option_no_checkout = 1;
 993                 if (!option_bare)
 994                         install_branch_config(0, "master", option_origin,
 995                                               "refs/heads/master");
 996         }
 997
 998         write_refspec_config(src_ref_prefix, our_head_points_at,
 999                         remote_head_points_at, &branch_top);
1000
1001         if (is_local)
1002                 clone_local(path, git_dir);
1003         else if (refs && complete_refs_before_fetch)
1004                 transport_fetch_refs(transport, mapped_refs);
1005
1006         update_remote_refs(refs, mapped_refs, remote_head_points_at,
1007                            branch_top.buf, reflog_msg.buf, transport, !is_local);
1008
1009         update_head(our_head_points_at, remote_head, reflog_msg.buf);
1010
1011         transport_unlock_pack(transport);
1012         transport_disconnect(transport);
1013
1014         if (option_dissociate)
1015                 dissociate_from_references();
1016
1017         junk_mode = JUNK_LEAVE_REPO;
1018         err = checkout();
1019
1020         strbuf_release(&reflog_msg);
1021         strbuf_release(&branch_top);
1022         strbuf_release(&key);
1023         strbuf_release(&value);
1024         junk_mode = JUNK_LEAVE_ALL;
1025
1026         free(refspec);
1027         return err;
1028 }