setup.c: support multi-checkout repo setup
[git] / 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
53 static int opt_parse_reference(const struct option *opt, const char *arg, int unset)
54 {
55         struct string_list *option_reference = opt->value;
56         if (!arg)
57                 return -1;
58         string_list_append(option_reference, arg);
59         return 0;
60 }
61
62 static struct option builtin_clone_options[] = {
63         OPT__VERBOSITY(&option_verbosity),
64         OPT_BOOL(0, "progress", &option_progress,
65                  N_("force progress reporting")),
66         OPT_BOOL('n', "no-checkout", &option_no_checkout,
67                  N_("don't create a checkout")),
68         OPT_BOOL(0, "bare", &option_bare, N_("create a bare repository")),
69         OPT_HIDDEN_BOOL(0, "naked", &option_bare,
70                         N_("create a bare repository")),
71         OPT_BOOL(0, "mirror", &option_mirror,
72                  N_("create a mirror repository (implies bare)")),
73         OPT_BOOL('l', "local", &option_local,
74                 N_("to clone from a local repository")),
75         OPT_BOOL(0, "no-hardlinks", &option_no_hardlinks,
76                     N_("don't use local hardlinks, always copy")),
77         OPT_BOOL('s', "shared", &option_shared,
78                     N_("setup as shared repository")),
79         OPT_BOOL(0, "recursive", &option_recursive,
80                     N_("initialize submodules in the clone")),
81         OPT_BOOL(0, "recurse-submodules", &option_recursive,
82                     N_("initialize submodules in the clone")),
83         OPT_STRING(0, "template", &option_template, N_("template-directory"),
84                    N_("directory from which templates will be used")),
85         OPT_CALLBACK(0 , "reference", &option_reference, N_("repo"),
86                      N_("reference repository"), &opt_parse_reference),
87         OPT_STRING('o', "origin", &option_origin, N_("name"),
88                    N_("use <name> instead of 'origin' to track upstream")),
89         OPT_STRING('b', "branch", &option_branch, N_("branch"),
90                    N_("checkout <branch> instead of the remote's HEAD")),
91         OPT_STRING('u', "upload-pack", &option_upload_pack, N_("path"),
92                    N_("path to git-upload-pack on the remote")),
93         OPT_STRING(0, "depth", &option_depth, N_("depth"),
94                     N_("create a shallow clone of that depth")),
95         OPT_BOOL(0, "single-branch", &option_single_branch,
96                     N_("clone only one branch, HEAD or --branch")),
97         OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
98                    N_("separate git dir from working tree")),
99         OPT_STRING_LIST('c', "config", &option_config, N_("key=value"),
100                         N_("set config inside the new repository")),
101         OPT_END()
102 };
103
104 static const char *argv_submodule[] = {
105         "submodule", "update", "--init", "--recursive", NULL
106 };
107
108 static char *get_repo_path(const char *repo, int *is_bundle)
109 {
110         static char *suffix[] = { "/.git", "", ".git/.git", ".git" };
111         static char *bundle_suffix[] = { ".bundle", "" };
112         struct stat st;
113         int i;
114
115         for (i = 0; i < ARRAY_SIZE(suffix); i++) {
116                 const char *path;
117                 path = mkpath("%s%s", repo, suffix[i]);
118                 if (stat(path, &st))
119                         continue;
120                 if (S_ISDIR(st.st_mode) && is_git_directory(path)) {
121                         *is_bundle = 0;
122                         return xstrdup(absolute_path(path));
123                 } else if (S_ISREG(st.st_mode) && st.st_size > 8) {
124                         /* Is it a "gitfile"? */
125                         char signature[8];
126                         int len, fd = open(path, O_RDONLY);
127                         if (fd < 0)
128                                 continue;
129                         len = read_in_full(fd, signature, 8);
130                         close(fd);
131                         if (len != 8 || strncmp(signature, "gitdir: ", 8))
132                                 continue;
133                         path = read_gitfile(path);
134                         if (path) {
135                                 *is_bundle = 0;
136                                 return xstrdup(absolute_path(path));
137                         }
138                 }
139         }
140
141         for (i = 0; i < ARRAY_SIZE(bundle_suffix); i++) {
142                 const char *path;
143                 path = mkpath("%s%s", repo, bundle_suffix[i]);
144                 if (!stat(path, &st) && S_ISREG(st.st_mode)) {
145                         *is_bundle = 1;
146                         return xstrdup(absolute_path(path));
147                 }
148         }
149
150         return NULL;
151 }
152
153 static char *guess_dir_name(const char *repo, int is_bundle, int is_bare)
154 {
155         const char *end = repo + strlen(repo), *start;
156         char *dir;
157
158         /*
159          * Strip trailing spaces, slashes and /.git
160          */
161         while (repo < end && (is_dir_sep(end[-1]) || isspace(end[-1])))
162                 end--;
163         if (end - repo > 5 && is_dir_sep(end[-5]) &&
164             !strncmp(end - 4, ".git", 4)) {
165                 end -= 5;
166                 while (repo < end && is_dir_sep(end[-1]))
167                         end--;
168         }
169
170         /*
171          * Find last component, but be prepared that repo could have
172          * the form  "remote.example.com:foo.git", i.e. no slash
173          * in the directory part.
174          */
175         start = end;
176         while (repo < start && !is_dir_sep(start[-1]) && start[-1] != ':')
177                 start--;
178
179         /*
180          * Strip .{bundle,git}.
181          */
182         if (is_bundle) {
183                 if (end - start > 7 && !strncmp(end - 7, ".bundle", 7))
184                         end -= 7;
185         } else {
186                 if (end - start > 4 && !strncmp(end - 4, ".git", 4))
187                         end -= 4;
188         }
189
190         if (is_bare) {
191                 struct strbuf result = STRBUF_INIT;
192                 strbuf_addf(&result, "%.*s.git", (int)(end - start), start);
193                 dir = strbuf_detach(&result, NULL);
194         } else
195                 dir = xstrndup(start, end - start);
196         /*
197          * Replace sequences of 'control' characters and whitespace
198          * with one ascii space, remove leading and trailing spaces.
199          */
200         if (*dir) {
201                 char *out = dir;
202                 int prev_space = 1 /* strip leading whitespace */;
203                 for (end = dir; *end; ++end) {
204                         char ch = *end;
205                         if ((unsigned char)ch < '\x20')
206                                 ch = '\x20';
207                         if (isspace(ch)) {
208                                 if (prev_space)
209                                         continue;
210                                 prev_space = 1;
211                         } else
212                                 prev_space = 0;
213                         *out++ = ch;
214                 }
215                 *out = '\0';
216                 if (out > dir && prev_space)
217                         out[-1] = '\0';
218         }
219         return dir;
220 }
221
222 static void strip_trailing_slashes(char *dir)
223 {
224         char *end = dir + strlen(dir);
225
226         while (dir < end - 1 && is_dir_sep(end[-1]))
227                 end--;
228         *end = '\0';
229 }
230
231 static int add_one_reference(struct string_list_item *item, void *cb_data)
232 {
233         char *ref_git;
234         const char *repo;
235         struct strbuf alternate = STRBUF_INIT;
236
237         /* Beware: read_gitfile(), real_path() and mkpath() return static buffer */
238         ref_git = xstrdup(real_path(item->string));
239
240         repo = read_gitfile(ref_git);
241         if (!repo)
242                 repo = read_gitfile(mkpath("%s/.git", ref_git));
243         if (repo) {
244                 free(ref_git);
245                 ref_git = xstrdup(repo);
246         }
247
248         if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
249                 char *ref_git_git = mkpathdup("%s/.git", ref_git);
250                 free(ref_git);
251                 ref_git = ref_git_git;
252         } else if (!is_directory(mkpath("%s/objects", ref_git)))
253                 die(_("reference repository '%s' is not a local repository."),
254                     item->string);
255
256         if (!access(mkpath("%s/shallow", ref_git), F_OK))
257                 die(_("reference repository '%s' is shallow"), item->string);
258
259         if (!access(mkpath("%s/info/grafts", ref_git), F_OK))
260                 die(_("reference repository '%s' is grafted"), item->string);
261
262         strbuf_addf(&alternate, "%s/objects", ref_git);
263         add_to_alternates_file(alternate.buf);
264         strbuf_release(&alternate);
265         free(ref_git);
266         return 0;
267 }
268
269 static void setup_reference(void)
270 {
271         for_each_string_list(&option_reference, add_one_reference, NULL);
272 }
273
274 static void copy_alternates(struct strbuf *src, struct strbuf *dst,
275                             const char *src_repo)
276 {
277         /*
278          * Read from the source objects/info/alternates file
279          * and copy the entries to corresponding file in the
280          * destination repository with add_to_alternates_file().
281          * Both src and dst have "$path/objects/info/alternates".
282          *
283          * Instead of copying bit-for-bit from the original,
284          * we need to append to existing one so that the already
285          * created entry via "clone -s" is not lost, and also
286          * to turn entries with paths relative to the original
287          * absolute, so that they can be used in the new repository.
288          */
289         FILE *in = fopen(src->buf, "r");
290         struct strbuf line = STRBUF_INIT;
291
292         while (strbuf_getline(&line, in, '\n') != EOF) {
293                 char *abs_path;
294                 if (!line.len || line.buf[0] == '#')
295                         continue;
296                 if (is_absolute_path(line.buf)) {
297                         add_to_alternates_file(line.buf);
298                         continue;
299                 }
300                 abs_path = mkpathdup("%s/objects/%s", src_repo, line.buf);
301                 normalize_path_copy(abs_path, abs_path);
302                 add_to_alternates_file(abs_path);
303                 free(abs_path);
304         }
305         strbuf_release(&line);
306         fclose(in);
307 }
308
309 static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
310                                    const char *src_repo, int src_baselen)
311 {
312         struct dirent *de;
313         struct stat buf;
314         int src_len, dest_len;
315         DIR *dir;
316
317         dir = opendir(src->buf);
318         if (!dir)
319                 die_errno(_("failed to open '%s'"), src->buf);
320
321         if (mkdir(dest->buf, 0777)) {
322                 if (errno != EEXIST)
323                         die_errno(_("failed to create directory '%s'"), dest->buf);
324                 else if (stat(dest->buf, &buf))
325                         die_errno(_("failed to stat '%s'"), dest->buf);
326                 else if (!S_ISDIR(buf.st_mode))
327                         die(_("%s exists and is not a directory"), dest->buf);
328         }
329
330         strbuf_addch(src, '/');
331         src_len = src->len;
332         strbuf_addch(dest, '/');
333         dest_len = dest->len;
334
335         while ((de = readdir(dir)) != NULL) {
336                 strbuf_setlen(src, src_len);
337                 strbuf_addstr(src, de->d_name);
338                 strbuf_setlen(dest, dest_len);
339                 strbuf_addstr(dest, de->d_name);
340                 if (stat(src->buf, &buf)) {
341                         warning (_("failed to stat %s\n"), src->buf);
342                         continue;
343                 }
344                 if (S_ISDIR(buf.st_mode)) {
345                         if (de->d_name[0] != '.')
346                                 copy_or_link_directory(src, dest,
347                                                        src_repo, src_baselen);
348                         continue;
349                 }
350
351                 /* Files that cannot be copied bit-for-bit... */
352                 if (!strcmp(src->buf + src_baselen, "/info/alternates")) {
353                         copy_alternates(src, dest, src_repo);
354                         continue;
355                 }
356
357                 if (unlink(dest->buf) && errno != ENOENT)
358                         die_errno(_("failed to unlink '%s'"), dest->buf);
359                 if (!option_no_hardlinks) {
360                         if (!link(src->buf, dest->buf))
361                                 continue;
362                         if (option_local > 0)
363                                 die_errno(_("failed to create link '%s'"), dest->buf);
364                         option_no_hardlinks = 1;
365                 }
366                 if (copy_file_with_time(dest->buf, src->buf, 0666))
367                         die_errno(_("failed to copy file to '%s'"), dest->buf);
368         }
369         closedir(dir);
370 }
371
372 static void clone_local(const char *src_repo, const char *dest_repo)
373 {
374         if (option_shared) {
375                 struct strbuf alt = STRBUF_INIT;
376                 strbuf_addf(&alt, "%s/objects", src_repo);
377                 add_to_alternates_file(alt.buf);
378                 strbuf_release(&alt);
379         } else {
380                 struct strbuf src = STRBUF_INIT;
381                 struct strbuf dest = STRBUF_INIT;
382                 strbuf_addf(&src, "%s/objects", src_repo);
383                 strbuf_addf(&dest, "%s/objects", dest_repo);
384                 copy_or_link_directory(&src, &dest, src_repo, src.len);
385                 strbuf_release(&src);
386                 strbuf_release(&dest);
387         }
388
389         if (0 <= option_verbosity)
390                 fprintf(stderr, _("done.\n"));
391 }
392
393 static const char *junk_work_tree;
394 static const char *junk_git_dir;
395 static enum {
396         JUNK_LEAVE_NONE,
397         JUNK_LEAVE_REPO,
398         JUNK_LEAVE_ALL
399 } junk_mode = JUNK_LEAVE_NONE;
400
401 static const char junk_leave_repo_msg[] =
402 N_("Clone succeeded, but checkout failed.\n"
403    "You can inspect what was checked out with 'git status'\n"
404    "and retry the checkout with 'git checkout -f HEAD'\n");
405
406 static void remove_junk(void)
407 {
408         struct strbuf sb = STRBUF_INIT;
409
410         switch (junk_mode) {
411         case JUNK_LEAVE_REPO:
412                 warning("%s", _(junk_leave_repo_msg));
413                 /* fall-through */
414         case JUNK_LEAVE_ALL:
415                 return;
416         default:
417                 /* proceed to removal */
418                 break;
419         }
420
421         if (junk_git_dir) {
422                 strbuf_addstr(&sb, junk_git_dir);
423                 remove_dir_recursively(&sb, 0);
424                 strbuf_reset(&sb);
425         }
426         if (junk_work_tree) {
427                 strbuf_addstr(&sb, junk_work_tree);
428                 remove_dir_recursively(&sb, 0);
429                 strbuf_reset(&sb);
430         }
431 }
432
433 static void remove_junk_on_signal(int signo)
434 {
435         remove_junk();
436         sigchain_pop(signo);
437         raise(signo);
438 }
439
440 static struct ref *find_remote_branch(const struct ref *refs, const char *branch)
441 {
442         struct ref *ref;
443         struct strbuf head = STRBUF_INIT;
444         strbuf_addstr(&head, "refs/heads/");
445         strbuf_addstr(&head, branch);
446         ref = find_ref_by_name(refs, head.buf);
447         strbuf_release(&head);
448
449         if (ref)
450                 return ref;
451
452         strbuf_addstr(&head, "refs/tags/");
453         strbuf_addstr(&head, branch);
454         ref = find_ref_by_name(refs, head.buf);
455         strbuf_release(&head);
456
457         return ref;
458 }
459
460 static struct ref *wanted_peer_refs(const struct ref *refs,
461                 struct refspec *refspec)
462 {
463         struct ref *head = copy_ref(find_ref_by_name(refs, "HEAD"));
464         struct ref *local_refs = head;
465         struct ref **tail = head ? &head->next : &local_refs;
466
467         if (option_single_branch) {
468                 struct ref *remote_head = NULL;
469
470                 if (!option_branch)
471                         remote_head = guess_remote_head(head, refs, 0);
472                 else {
473                         local_refs = NULL;
474                         tail = &local_refs;
475                         remote_head = copy_ref(find_remote_branch(refs, option_branch));
476                 }
477
478                 if (!remote_head && option_branch)
479                         warning(_("Could not find remote branch %s to clone."),
480                                 option_branch);
481                 else {
482                         get_fetch_map(remote_head, refspec, &tail, 0);
483
484                         /* if --branch=tag, pull the requested tag explicitly */
485                         get_fetch_map(remote_head, tag_refspec, &tail, 0);
486                 }
487         } else
488                 get_fetch_map(refs, refspec, &tail, 0);
489
490         if (!option_mirror && !option_single_branch)
491                 get_fetch_map(refs, tag_refspec, &tail, 0);
492
493         return local_refs;
494 }
495
496 static void write_remote_refs(const struct ref *local_refs)
497 {
498         const struct ref *r;
499
500         lock_packed_refs(LOCK_DIE_ON_ERROR);
501
502         for (r = local_refs; r; r = r->next) {
503                 if (!r->peer_ref)
504                         continue;
505                 add_packed_ref(r->peer_ref->name, r->old_sha1);
506         }
507
508         if (commit_packed_refs())
509                 die_errno("unable to overwrite old ref-pack file");
510 }
511
512 static void write_followtags(const struct ref *refs, const char *msg)
513 {
514         const struct ref *ref;
515         for (ref = refs; ref; ref = ref->next) {
516                 if (!starts_with(ref->name, "refs/tags/"))
517                         continue;
518                 if (ends_with(ref->name, "^{}"))
519                         continue;
520                 if (!has_sha1_file(ref->old_sha1))
521                         continue;
522                 update_ref(msg, ref->name, ref->old_sha1,
523                            NULL, 0, UPDATE_REFS_DIE_ON_ERR);
524         }
525 }
526
527 static int iterate_ref_map(void *cb_data, unsigned char sha1[20])
528 {
529         struct ref **rm = cb_data;
530         struct ref *ref = *rm;
531
532         /*
533          * Skip anything missing a peer_ref, which we are not
534          * actually going to write a ref for.
535          */
536         while (ref && !ref->peer_ref)
537                 ref = ref->next;
538         /* Returning -1 notes "end of list" to the caller. */
539         if (!ref)
540                 return -1;
541
542         hashcpy(sha1, ref->old_sha1);
543         *rm = ref->next;
544         return 0;
545 }
546
547 static void update_remote_refs(const struct ref *refs,
548                                const struct ref *mapped_refs,
549                                const struct ref *remote_head_points_at,
550                                const char *branch_top,
551                                const char *msg,
552                                struct transport *transport,
553                                int check_connectivity)
554 {
555         const struct ref *rm = mapped_refs;
556
557         if (check_connectivity) {
558                 if (transport->progress)
559                         fprintf(stderr, _("Checking connectivity... "));
560                 if (check_everything_connected_with_transport(iterate_ref_map,
561                                                               0, &rm, transport))
562                         die(_("remote did not send all necessary objects"));
563                 if (transport->progress)
564                         fprintf(stderr, _("done.\n"));
565         }
566
567         if (refs) {
568                 write_remote_refs(mapped_refs);
569                 if (option_single_branch)
570                         write_followtags(refs, msg);
571         }
572
573         if (remote_head_points_at && !option_bare) {
574                 struct strbuf head_ref = STRBUF_INIT;
575                 strbuf_addstr(&head_ref, branch_top);
576                 strbuf_addstr(&head_ref, "HEAD");
577                 create_symref(head_ref.buf,
578                               remote_head_points_at->peer_ref->name,
579                               msg);
580         }
581 }
582
583 static void update_head(const struct ref *our, const struct ref *remote,
584                         const char *msg)
585 {
586         const char *head;
587         if (our && skip_prefix(our->name, "refs/heads/", &head)) {
588                 /* Local default branch link */
589                 create_symref("HEAD", our->name, NULL);
590                 if (!option_bare) {
591                         update_ref(msg, "HEAD", our->old_sha1, NULL, 0,
592                                    UPDATE_REFS_DIE_ON_ERR);
593                         install_branch_config(0, head, option_origin, our->name);
594                 }
595         } else if (our) {
596                 struct commit *c = lookup_commit_reference(our->old_sha1);
597                 /* --branch specifies a non-branch (i.e. tags), detach HEAD */
598                 update_ref(msg, "HEAD", c->object.sha1,
599                            NULL, REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
600         } else if (remote) {
601                 /*
602                  * We know remote HEAD points to a non-branch, or
603                  * HEAD points to a branch but we don't know which one.
604                  * Detach HEAD in all these cases.
605                  */
606                 update_ref(msg, "HEAD", remote->old_sha1,
607                            NULL, REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
608         }
609 }
610
611 static int checkout(void)
612 {
613         unsigned char sha1[20];
614         char *head;
615         struct lock_file *lock_file;
616         struct unpack_trees_options opts;
617         struct tree *tree;
618         struct tree_desc t;
619         int err = 0;
620
621         if (option_no_checkout)
622                 return 0;
623
624         head = resolve_refdup("HEAD", RESOLVE_REF_READING, sha1, NULL);
625         if (!head) {
626                 warning(_("remote HEAD refers to nonexistent ref, "
627                           "unable to checkout.\n"));
628                 return 0;
629         }
630         if (!strcmp(head, "HEAD")) {
631                 if (advice_detached_head)
632                         detach_advice(sha1_to_hex(sha1));
633         } else {
634                 if (!starts_with(head, "refs/heads/"))
635                         die(_("HEAD not found below refs/heads!"));
636         }
637         free(head);
638
639         /* We need to be in the new work tree for the checkout */
640         setup_work_tree();
641
642         lock_file = xcalloc(1, sizeof(struct lock_file));
643         hold_locked_index(lock_file, 1);
644
645         memset(&opts, 0, sizeof opts);
646         opts.update = 1;
647         opts.merge = 1;
648         opts.fn = oneway_merge;
649         opts.verbose_update = (option_verbosity >= 0);
650         opts.src_index = &the_index;
651         opts.dst_index = &the_index;
652
653         tree = parse_tree_indirect(sha1);
654         parse_tree(tree);
655         init_tree_desc(&t, tree->buffer, tree->size);
656         if (unpack_trees(1, &t, &opts) < 0)
657                 die(_("unable to checkout working tree"));
658
659         if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
660                 die(_("unable to write new index file"));
661
662         err |= run_hook_le(NULL, "post-checkout", sha1_to_hex(null_sha1),
663                            sha1_to_hex(sha1), "1", NULL);
664
665         if (!err && option_recursive)
666                 err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
667
668         return err;
669 }
670
671 static int write_one_config(const char *key, const char *value, void *data)
672 {
673         return git_config_set_multivar(key, value ? value : "true", "^$", 0);
674 }
675
676 static void write_config(struct string_list *config)
677 {
678         int i;
679
680         for (i = 0; i < config->nr; i++) {
681                 if (git_config_parse_parameter(config->items[i].string,
682                                                write_one_config, NULL) < 0)
683                         die("unable to write parameters to config file");
684         }
685 }
686
687 static void write_refspec_config(const char *src_ref_prefix,
688                 const struct ref *our_head_points_at,
689                 const struct ref *remote_head_points_at,
690                 struct strbuf *branch_top)
691 {
692         struct strbuf key = STRBUF_INIT;
693         struct strbuf value = STRBUF_INIT;
694
695         if (option_mirror || !option_bare) {
696                 if (option_single_branch && !option_mirror) {
697                         if (option_branch) {
698                                 if (starts_with(our_head_points_at->name, "refs/tags/"))
699                                         strbuf_addf(&value, "+%s:%s", our_head_points_at->name,
700                                                 our_head_points_at->name);
701                                 else
702                                         strbuf_addf(&value, "+%s:%s%s", our_head_points_at->name,
703                                                 branch_top->buf, option_branch);
704                         } else if (remote_head_points_at) {
705                                 const char *head = remote_head_points_at->name;
706                                 if (!skip_prefix(head, "refs/heads/", &head))
707                                         die("BUG: remote HEAD points at non-head?");
708
709                                 strbuf_addf(&value, "+%s:%s%s", remote_head_points_at->name,
710                                                 branch_top->buf, head);
711                         }
712                         /*
713                          * otherwise, the next "git fetch" will
714                          * simply fetch from HEAD without updating
715                          * any remote-tracking branch, which is what
716                          * we want.
717                          */
718                 } else {
719                         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top->buf);
720                 }
721                 /* Configure the remote */
722                 if (value.len) {
723                         strbuf_addf(&key, "remote.%s.fetch", option_origin);
724                         git_config_set_multivar(key.buf, value.buf, "^$", 0);
725                         strbuf_reset(&key);
726
727                         if (option_mirror) {
728                                 strbuf_addf(&key, "remote.%s.mirror", option_origin);
729                                 git_config_set(key.buf, "true");
730                                 strbuf_reset(&key);
731                         }
732                 }
733         }
734
735         strbuf_release(&key);
736         strbuf_release(&value);
737 }
738
739 int cmd_clone(int argc, const char **argv, const char *prefix)
740 {
741         int is_bundle = 0, is_local;
742         struct stat buf;
743         const char *repo_name, *repo, *work_tree, *git_dir;
744         char *path, *dir;
745         int dest_exists;
746         const struct ref *refs, *remote_head;
747         const struct ref *remote_head_points_at;
748         const struct ref *our_head_points_at;
749         struct ref *mapped_refs;
750         const struct ref *ref;
751         struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
752         struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
753         struct transport *transport = NULL;
754         const char *src_ref_prefix = "refs/heads/";
755         struct remote *remote;
756         int err = 0, complete_refs_before_fetch = 1;
757
758         struct refspec *refspec;
759         const char *fetch_pattern;
760
761         packet_trace_identity("clone");
762         argc = parse_options(argc, argv, prefix, builtin_clone_options,
763                              builtin_clone_usage, 0);
764
765         if (argc > 2)
766                 usage_msg_opt(_("Too many arguments."),
767                         builtin_clone_usage, builtin_clone_options);
768
769         if (argc == 0)
770                 usage_msg_opt(_("You must specify a repository to clone."),
771                         builtin_clone_usage, builtin_clone_options);
772
773         if (option_single_branch == -1)
774                 option_single_branch = option_depth ? 1 : 0;
775
776         if (option_mirror)
777                 option_bare = 1;
778
779         if (option_bare) {
780                 if (option_origin)
781                         die(_("--bare and --origin %s options are incompatible."),
782                             option_origin);
783                 if (real_git_dir)
784                         die(_("--bare and --separate-git-dir are incompatible."));
785                 option_no_checkout = 1;
786         }
787
788         if (!option_origin)
789                 option_origin = "origin";
790
791         repo_name = argv[0];
792
793         path = get_repo_path(repo_name, &is_bundle);
794         if (path)
795                 repo = xstrdup(absolute_path(repo_name));
796         else if (!strchr(repo_name, ':'))
797                 die(_("repository '%s' does not exist"), repo_name);
798         else
799                 repo = repo_name;
800
801         /* no need to be strict, transport_set_option() will validate it again */
802         if (option_depth && atoi(option_depth) < 1)
803                 die(_("depth %s is not a positive number"), option_depth);
804
805         if (argc == 2)
806                 dir = xstrdup(argv[1]);
807         else
808                 dir = guess_dir_name(repo_name, is_bundle, option_bare);
809         strip_trailing_slashes(dir);
810
811         dest_exists = !stat(dir, &buf);
812         if (dest_exists && !is_empty_dir(dir))
813                 die(_("destination path '%s' already exists and is not "
814                         "an empty directory."), dir);
815
816         strbuf_addf(&reflog_msg, "clone: from %s", repo);
817
818         if (option_bare)
819                 work_tree = NULL;
820         else {
821                 work_tree = getenv("GIT_WORK_TREE");
822                 if (work_tree && !stat(work_tree, &buf))
823                         die(_("working tree '%s' already exists."), work_tree);
824         }
825
826         if (option_bare || work_tree)
827                 git_dir = xstrdup(dir);
828         else {
829                 work_tree = dir;
830                 git_dir = mkpathdup("%s/.git", dir);
831         }
832
833         if (!option_bare) {
834                 junk_work_tree = work_tree;
835                 if (safe_create_leading_directories_const(work_tree) < 0)
836                         die_errno(_("could not create leading directories of '%s'"),
837                                   work_tree);
838                 if (!dest_exists && mkdir(work_tree, 0777))
839                         die_errno(_("could not create work tree dir '%s'."),
840                                   work_tree);
841                 set_git_work_tree(work_tree);
842         }
843         junk_git_dir = git_dir;
844         atexit(remove_junk);
845         sigchain_push_common(remove_junk_on_signal);
846
847         if (safe_create_leading_directories_const(git_dir) < 0)
848                 die(_("could not create leading directories of '%s'"), git_dir);
849
850         set_git_dir_init(git_dir, real_git_dir, 0);
851         if (real_git_dir) {
852                 git_dir = real_git_dir;
853                 junk_git_dir = real_git_dir;
854         }
855
856         if (0 <= option_verbosity) {
857                 if (option_bare)
858                         fprintf(stderr, _("Cloning into bare repository '%s'...\n"), dir);
859                 else
860                         fprintf(stderr, _("Cloning into '%s'...\n"), dir);
861         }
862         init_db(option_template, INIT_DB_QUIET);
863         write_config(&option_config);
864
865         git_config(git_default_config, NULL);
866
867         if (option_bare) {
868                 if (option_mirror)
869                         src_ref_prefix = "refs/";
870                 strbuf_addstr(&branch_top, src_ref_prefix);
871
872                 git_config_set("core.bare", "true");
873         } else {
874                 strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
875         }
876
877         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
878         strbuf_addf(&key, "remote.%s.url", option_origin);
879         git_config_set(key.buf, repo);
880         strbuf_reset(&key);
881
882         if (option_reference.nr)
883                 setup_reference();
884
885         fetch_pattern = value.buf;
886         refspec = parse_fetch_refspec(1, &fetch_pattern);
887
888         strbuf_reset(&value);
889
890         remote = remote_get(option_origin);
891         transport = transport_get(remote, remote->url[0]);
892         path = get_repo_path(remote->url[0], &is_bundle);
893         is_local = option_local != 0 && path && !is_bundle;
894         if (is_local) {
895                 if (option_depth)
896                         warning(_("--depth is ignored in local clones; use file:// instead."));
897                 if (!access(mkpath("%s/shallow", path), F_OK)) {
898                         if (option_local > 0)
899                                 warning(_("source repository is shallow, ignoring --local"));
900                         is_local = 0;
901                 }
902         }
903         if (option_local > 0 && !is_local)
904                 warning(_("--local is ignored"));
905         transport->cloning = 1;
906
907         if (!transport->get_refs_list || (!is_local && !transport->fetch))
908                 die(_("Don't know how to clone %s"), transport->url);
909
910         transport_set_option(transport, TRANS_OPT_KEEP, "yes");
911
912         if (option_depth)
913                 transport_set_option(transport, TRANS_OPT_DEPTH,
914                                      option_depth);
915         if (option_single_branch)
916                 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
917
918         transport_set_verbosity(transport, option_verbosity, option_progress);
919
920         if (option_upload_pack)
921                 transport_set_option(transport, TRANS_OPT_UPLOADPACK,
922                                      option_upload_pack);
923
924         if (transport->smart_options && !option_depth)
925                 transport->smart_options->check_self_contained_and_connected = 1;
926
927         refs = transport_get_remote_refs(transport);
928
929         if (refs) {
930                 mapped_refs = wanted_peer_refs(refs, refspec);
931                 /*
932                  * transport_get_remote_refs() may return refs with null sha-1
933                  * in mapped_refs (see struct transport->get_refs_list
934                  * comment). In that case we need fetch it early because
935                  * remote_head code below relies on it.
936                  *
937                  * for normal clones, transport_get_remote_refs() should
938                  * return reliable ref set, we can delay cloning until after
939                  * remote HEAD check.
940                  */
941                 for (ref = refs; ref; ref = ref->next)
942                         if (is_null_sha1(ref->old_sha1)) {
943                                 complete_refs_before_fetch = 0;
944                                 break;
945                         }
946
947                 if (!is_local && !complete_refs_before_fetch)
948                         transport_fetch_refs(transport, mapped_refs);
949
950                 remote_head = find_ref_by_name(refs, "HEAD");
951                 remote_head_points_at =
952                         guess_remote_head(remote_head, mapped_refs, 0);
953
954                 if (option_branch) {
955                         our_head_points_at =
956                                 find_remote_branch(mapped_refs, option_branch);
957
958                         if (!our_head_points_at)
959                                 die(_("Remote branch %s not found in upstream %s"),
960                                     option_branch, option_origin);
961                 }
962                 else
963                         our_head_points_at = remote_head_points_at;
964         }
965         else {
966                 if (option_branch)
967                         die(_("Remote branch %s not found in upstream %s"),
968                                         option_branch, option_origin);
969
970                 warning(_("You appear to have cloned an empty repository."));
971                 mapped_refs = NULL;
972                 our_head_points_at = NULL;
973                 remote_head_points_at = NULL;
974                 remote_head = NULL;
975                 option_no_checkout = 1;
976                 if (!option_bare)
977                         install_branch_config(0, "master", option_origin,
978                                               "refs/heads/master");
979         }
980
981         write_refspec_config(src_ref_prefix, our_head_points_at,
982                         remote_head_points_at, &branch_top);
983
984         if (is_local)
985                 clone_local(path, git_dir);
986         else if (refs && complete_refs_before_fetch)
987                 transport_fetch_refs(transport, mapped_refs);
988
989         update_remote_refs(refs, mapped_refs, remote_head_points_at,
990                            branch_top.buf, reflog_msg.buf, transport, !is_local);
991
992         update_head(our_head_points_at, remote_head, reflog_msg.buf);
993
994         transport_unlock_pack(transport);
995         transport_disconnect(transport);
996
997         junk_mode = JUNK_LEAVE_REPO;
998         err = checkout();
999
1000         strbuf_release(&reflog_msg);
1001         strbuf_release(&branch_top);
1002         strbuf_release(&key);
1003         strbuf_release(&value);
1004         junk_mode = JUNK_LEAVE_ALL;
1005
1006         free(refspec);
1007         return err;
1008 }