clone: implement optional references
[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 int option_shallow_submodules;
44 static char *option_template, *option_depth;
45 static char *option_origin = NULL;
46 static char *option_branch = NULL;
47 static const char *real_git_dir;
48 static char *option_upload_pack = "git-upload-pack";
49 static int option_verbosity;
50 static int option_progress = -1;
51 static enum transport_family family;
52 static struct string_list option_config = STRING_LIST_INIT_NODUP;
53 static struct string_list option_required_reference = STRING_LIST_INIT_NODUP;
54 static struct string_list option_optional_reference = STRING_LIST_INIT_NODUP;
55 static int option_dissociate;
56 static int max_jobs = -1;
57
58 static struct option builtin_clone_options[] = {
59         OPT__VERBOSITY(&option_verbosity),
60         OPT_BOOL(0, "progress", &option_progress,
61                  N_("force progress reporting")),
62         OPT_BOOL('n', "no-checkout", &option_no_checkout,
63                  N_("don't create a checkout")),
64         OPT_BOOL(0, "bare", &option_bare, N_("create a bare repository")),
65         OPT_HIDDEN_BOOL(0, "naked", &option_bare,
66                         N_("create a bare repository")),
67         OPT_BOOL(0, "mirror", &option_mirror,
68                  N_("create a mirror repository (implies bare)")),
69         OPT_BOOL('l', "local", &option_local,
70                 N_("to clone from a local repository")),
71         OPT_BOOL(0, "no-hardlinks", &option_no_hardlinks,
72                     N_("don't use local hardlinks, always copy")),
73         OPT_BOOL('s', "shared", &option_shared,
74                     N_("setup as shared repository")),
75         OPT_BOOL(0, "recursive", &option_recursive,
76                     N_("initialize submodules in the clone")),
77         OPT_BOOL(0, "recurse-submodules", &option_recursive,
78                     N_("initialize submodules in the clone")),
79         OPT_INTEGER('j', "jobs", &max_jobs,
80                     N_("number of submodules cloned in parallel")),
81         OPT_STRING(0, "template", &option_template, N_("template-directory"),
82                    N_("directory from which templates will be used")),
83         OPT_STRING_LIST(0, "reference", &option_required_reference, N_("repo"),
84                         N_("reference repository")),
85         OPT_STRING_LIST(0, "reference-if-able", &option_optional_reference,
86                         N_("repo"), N_("reference repository")),
87         OPT_BOOL(0, "dissociate", &option_dissociate,
88                  N_("use --reference only while cloning")),
89         OPT_STRING('o', "origin", &option_origin, N_("name"),
90                    N_("use <name> instead of 'origin' to track upstream")),
91         OPT_STRING('b', "branch", &option_branch, N_("branch"),
92                    N_("checkout <branch> instead of the remote's HEAD")),
93         OPT_STRING('u', "upload-pack", &option_upload_pack, N_("path"),
94                    N_("path to git-upload-pack on the remote")),
95         OPT_STRING(0, "depth", &option_depth, N_("depth"),
96                     N_("create a shallow clone of that depth")),
97         OPT_BOOL(0, "single-branch", &option_single_branch,
98                     N_("clone only one branch, HEAD or --branch")),
99         OPT_BOOL(0, "shallow-submodules", &option_shallow_submodules,
100                     N_("any cloned submodules will be shallow")),
101         OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
102                    N_("separate git dir from working tree")),
103         OPT_STRING_LIST('c', "config", &option_config, N_("key=value"),
104                         N_("set config inside the new repository")),
105         OPT_SET_INT('4', "ipv4", &family, N_("use IPv4 addresses only"),
106                         TRANSPORT_FAMILY_IPV4),
107         OPT_SET_INT('6', "ipv6", &family, N_("use IPv6 addresses only"),
108                         TRANSPORT_FAMILY_IPV6),
109         OPT_END()
110 };
111
112 static const char *get_repo_path_1(struct strbuf *path, int *is_bundle)
113 {
114         static char *suffix[] = { "/.git", "", ".git/.git", ".git" };
115         static char *bundle_suffix[] = { ".bundle", "" };
116         size_t baselen = path->len;
117         struct stat st;
118         int i;
119
120         for (i = 0; i < ARRAY_SIZE(suffix); i++) {
121                 strbuf_setlen(path, baselen);
122                 strbuf_addstr(path, suffix[i]);
123                 if (stat(path->buf, &st))
124                         continue;
125                 if (S_ISDIR(st.st_mode) && is_git_directory(path->buf)) {
126                         *is_bundle = 0;
127                         return path->buf;
128                 } else if (S_ISREG(st.st_mode) && st.st_size > 8) {
129                         /* Is it a "gitfile"? */
130                         char signature[8];
131                         const char *dst;
132                         int len, fd = open(path->buf, O_RDONLY);
133                         if (fd < 0)
134                                 continue;
135                         len = read_in_full(fd, signature, 8);
136                         close(fd);
137                         if (len != 8 || strncmp(signature, "gitdir: ", 8))
138                                 continue;
139                         dst = read_gitfile(path->buf);
140                         if (dst) {
141                                 *is_bundle = 0;
142                                 return dst;
143                         }
144                 }
145         }
146
147         for (i = 0; i < ARRAY_SIZE(bundle_suffix); i++) {
148                 strbuf_setlen(path, baselen);
149                 strbuf_addstr(path, bundle_suffix[i]);
150                 if (!stat(path->buf, &st) && S_ISREG(st.st_mode)) {
151                         *is_bundle = 1;
152                         return path->buf;
153                 }
154         }
155
156         return NULL;
157 }
158
159 static char *get_repo_path(const char *repo, int *is_bundle)
160 {
161         struct strbuf path = STRBUF_INIT;
162         const char *raw;
163         char *canon;
164
165         strbuf_addstr(&path, repo);
166         raw = get_repo_path_1(&path, is_bundle);
167         canon = raw ? xstrdup(absolute_path(raw)) : NULL;
168         strbuf_release(&path);
169         return canon;
170 }
171
172 static char *guess_dir_name(const char *repo, int is_bundle, int is_bare)
173 {
174         const char *end = repo + strlen(repo), *start, *ptr;
175         size_t len;
176         char *dir;
177
178         /*
179          * Skip scheme.
180          */
181         start = strstr(repo, "://");
182         if (start == NULL)
183                 start = repo;
184         else
185                 start += 3;
186
187         /*
188          * Skip authentication data. The stripping does happen
189          * greedily, such that we strip up to the last '@' inside
190          * the host part.
191          */
192         for (ptr = start; ptr < end && !is_dir_sep(*ptr); ptr++) {
193                 if (*ptr == '@')
194                         start = ptr + 1;
195         }
196
197         /*
198          * Strip trailing spaces, slashes and /.git
199          */
200         while (start < end && (is_dir_sep(end[-1]) || isspace(end[-1])))
201                 end--;
202         if (end - start > 5 && is_dir_sep(end[-5]) &&
203             !strncmp(end - 4, ".git", 4)) {
204                 end -= 5;
205                 while (start < end && is_dir_sep(end[-1]))
206                         end--;
207         }
208
209         /*
210          * Strip trailing port number if we've got only a
211          * hostname (that is, there is no dir separator but a
212          * colon). This check is required such that we do not
213          * strip URI's like '/foo/bar:2222.git', which should
214          * result in a dir '2222' being guessed due to backwards
215          * compatibility.
216          */
217         if (memchr(start, '/', end - start) == NULL
218             && memchr(start, ':', end - start) != NULL) {
219                 ptr = end;
220                 while (start < ptr && isdigit(ptr[-1]) && ptr[-1] != ':')
221                         ptr--;
222                 if (start < ptr && ptr[-1] == ':')
223                         end = ptr - 1;
224         }
225
226         /*
227          * Find last component. To remain backwards compatible we
228          * also regard colons as path separators, such that
229          * cloning a repository 'foo:bar.git' would result in a
230          * directory 'bar' being guessed.
231          */
232         ptr = end;
233         while (start < ptr && !is_dir_sep(ptr[-1]) && ptr[-1] != ':')
234                 ptr--;
235         start = ptr;
236
237         /*
238          * Strip .{bundle,git}.
239          */
240         len = end - start;
241         strip_suffix_mem(start, &len, is_bundle ? ".bundle" : ".git");
242
243         if (!len || (len == 1 && *start == '/'))
244                 die(_("No directory name could be guessed.\n"
245                       "Please specify a directory on the command line"));
246
247         if (is_bare)
248                 dir = xstrfmt("%.*s.git", (int)len, start);
249         else
250                 dir = xstrndup(start, len);
251         /*
252          * Replace sequences of 'control' characters and whitespace
253          * with one ascii space, remove leading and trailing spaces.
254          */
255         if (*dir) {
256                 char *out = dir;
257                 int prev_space = 1 /* strip leading whitespace */;
258                 for (end = dir; *end; ++end) {
259                         char ch = *end;
260                         if ((unsigned char)ch < '\x20')
261                                 ch = '\x20';
262                         if (isspace(ch)) {
263                                 if (prev_space)
264                                         continue;
265                                 prev_space = 1;
266                         } else
267                                 prev_space = 0;
268                         *out++ = ch;
269                 }
270                 *out = '\0';
271                 if (out > dir && prev_space)
272                         out[-1] = '\0';
273         }
274         return dir;
275 }
276
277 static void strip_trailing_slashes(char *dir)
278 {
279         char *end = dir + strlen(dir);
280
281         while (dir < end - 1 && is_dir_sep(end[-1]))
282                 end--;
283         *end = '\0';
284 }
285
286 static int add_one_reference(struct string_list_item *item, void *cb_data)
287 {
288         struct strbuf err = STRBUF_INIT;
289         int *required = cb_data;
290         char *ref_git = compute_alternate_path(item->string, &err);
291
292         if (!ref_git) {
293                 if (*required)
294                         die("%s", err.buf);
295                 else
296                         fprintf(stderr,
297                                 _("info: Could not add alternate for '%s': %s\n"),
298                                 item->string, err.buf);
299         } else {
300                 struct strbuf sb = STRBUF_INIT;
301                 strbuf_addf(&sb, "%s/objects", ref_git);
302                 add_to_alternates_file(sb.buf);
303                 strbuf_release(&sb);
304         }
305
306         strbuf_release(&err);
307         free(ref_git);
308         return 0;
309 }
310
311 static void setup_reference(void)
312 {
313         int required = 1;
314         for_each_string_list(&option_required_reference,
315                              add_one_reference, &required);
316         required = 0;
317         for_each_string_list(&option_optional_reference,
318                              add_one_reference, &required);
319 }
320
321 static void copy_alternates(struct strbuf *src, struct strbuf *dst,
322                             const char *src_repo)
323 {
324         /*
325          * Read from the source objects/info/alternates file
326          * and copy the entries to corresponding file in the
327          * destination repository with add_to_alternates_file().
328          * Both src and dst have "$path/objects/info/alternates".
329          *
330          * Instead of copying bit-for-bit from the original,
331          * we need to append to existing one so that the already
332          * created entry via "clone -s" is not lost, and also
333          * to turn entries with paths relative to the original
334          * absolute, so that they can be used in the new repository.
335          */
336         FILE *in = fopen(src->buf, "r");
337         struct strbuf line = STRBUF_INIT;
338
339         while (strbuf_getline(&line, in) != EOF) {
340                 char *abs_path;
341                 if (!line.len || line.buf[0] == '#')
342                         continue;
343                 if (is_absolute_path(line.buf)) {
344                         add_to_alternates_file(line.buf);
345                         continue;
346                 }
347                 abs_path = mkpathdup("%s/objects/%s", src_repo, line.buf);
348                 normalize_path_copy(abs_path, abs_path);
349                 add_to_alternates_file(abs_path);
350                 free(abs_path);
351         }
352         strbuf_release(&line);
353         fclose(in);
354 }
355
356 static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
357                                    const char *src_repo, int src_baselen)
358 {
359         struct dirent *de;
360         struct stat buf;
361         int src_len, dest_len;
362         DIR *dir;
363
364         dir = opendir(src->buf);
365         if (!dir)
366                 die_errno(_("failed to open '%s'"), src->buf);
367
368         if (mkdir(dest->buf, 0777)) {
369                 if (errno != EEXIST)
370                         die_errno(_("failed to create directory '%s'"), dest->buf);
371                 else if (stat(dest->buf, &buf))
372                         die_errno(_("failed to stat '%s'"), dest->buf);
373                 else if (!S_ISDIR(buf.st_mode))
374                         die(_("%s exists and is not a directory"), dest->buf);
375         }
376
377         strbuf_addch(src, '/');
378         src_len = src->len;
379         strbuf_addch(dest, '/');
380         dest_len = dest->len;
381
382         while ((de = readdir(dir)) != NULL) {
383                 strbuf_setlen(src, src_len);
384                 strbuf_addstr(src, de->d_name);
385                 strbuf_setlen(dest, dest_len);
386                 strbuf_addstr(dest, de->d_name);
387                 if (stat(src->buf, &buf)) {
388                         warning (_("failed to stat %s\n"), src->buf);
389                         continue;
390                 }
391                 if (S_ISDIR(buf.st_mode)) {
392                         if (de->d_name[0] != '.')
393                                 copy_or_link_directory(src, dest,
394                                                        src_repo, src_baselen);
395                         continue;
396                 }
397
398                 /* Files that cannot be copied bit-for-bit... */
399                 if (!strcmp(src->buf + src_baselen, "/info/alternates")) {
400                         copy_alternates(src, dest, src_repo);
401                         continue;
402                 }
403
404                 if (unlink(dest->buf) && errno != ENOENT)
405                         die_errno(_("failed to unlink '%s'"), dest->buf);
406                 if (!option_no_hardlinks) {
407                         if (!link(src->buf, dest->buf))
408                                 continue;
409                         if (option_local > 0)
410                                 die_errno(_("failed to create link '%s'"), dest->buf);
411                         option_no_hardlinks = 1;
412                 }
413                 if (copy_file_with_time(dest->buf, src->buf, 0666))
414                         die_errno(_("failed to copy file to '%s'"), dest->buf);
415         }
416         closedir(dir);
417 }
418
419 static void clone_local(const char *src_repo, const char *dest_repo)
420 {
421         if (option_shared) {
422                 struct strbuf alt = STRBUF_INIT;
423                 strbuf_addf(&alt, "%s/objects", src_repo);
424                 add_to_alternates_file(alt.buf);
425                 strbuf_release(&alt);
426         } else {
427                 struct strbuf src = STRBUF_INIT;
428                 struct strbuf dest = STRBUF_INIT;
429                 get_common_dir(&src, src_repo);
430                 get_common_dir(&dest, dest_repo);
431                 strbuf_addstr(&src, "/objects");
432                 strbuf_addstr(&dest, "/objects");
433                 copy_or_link_directory(&src, &dest, src_repo, src.len);
434                 strbuf_release(&src);
435                 strbuf_release(&dest);
436         }
437
438         if (0 <= option_verbosity)
439                 fprintf(stderr, _("done.\n"));
440 }
441
442 static const char *junk_work_tree;
443 static const char *junk_git_dir;
444 static enum {
445         JUNK_LEAVE_NONE,
446         JUNK_LEAVE_REPO,
447         JUNK_LEAVE_ALL
448 } junk_mode = JUNK_LEAVE_NONE;
449
450 static const char junk_leave_repo_msg[] =
451 N_("Clone succeeded, but checkout failed.\n"
452    "You can inspect what was checked out with 'git status'\n"
453    "and retry the checkout with 'git checkout -f HEAD'\n");
454
455 static void remove_junk(void)
456 {
457         struct strbuf sb = STRBUF_INIT;
458
459         switch (junk_mode) {
460         case JUNK_LEAVE_REPO:
461                 warning("%s", _(junk_leave_repo_msg));
462                 /* fall-through */
463         case JUNK_LEAVE_ALL:
464                 return;
465         default:
466                 /* proceed to removal */
467                 break;
468         }
469
470         if (junk_git_dir) {
471                 strbuf_addstr(&sb, junk_git_dir);
472                 remove_dir_recursively(&sb, 0);
473                 strbuf_reset(&sb);
474         }
475         if (junk_work_tree) {
476                 strbuf_addstr(&sb, junk_work_tree);
477                 remove_dir_recursively(&sb, 0);
478                 strbuf_reset(&sb);
479         }
480 }
481
482 static void remove_junk_on_signal(int signo)
483 {
484         remove_junk();
485         sigchain_pop(signo);
486         raise(signo);
487 }
488
489 static struct ref *find_remote_branch(const struct ref *refs, const char *branch)
490 {
491         struct ref *ref;
492         struct strbuf head = STRBUF_INIT;
493         strbuf_addstr(&head, "refs/heads/");
494         strbuf_addstr(&head, branch);
495         ref = find_ref_by_name(refs, head.buf);
496         strbuf_release(&head);
497
498         if (ref)
499                 return ref;
500
501         strbuf_addstr(&head, "refs/tags/");
502         strbuf_addstr(&head, branch);
503         ref = find_ref_by_name(refs, head.buf);
504         strbuf_release(&head);
505
506         return ref;
507 }
508
509 static struct ref *wanted_peer_refs(const struct ref *refs,
510                 struct refspec *refspec)
511 {
512         struct ref *head = copy_ref(find_ref_by_name(refs, "HEAD"));
513         struct ref *local_refs = head;
514         struct ref **tail = head ? &head->next : &local_refs;
515
516         if (option_single_branch) {
517                 struct ref *remote_head = NULL;
518
519                 if (!option_branch)
520                         remote_head = guess_remote_head(head, refs, 0);
521                 else {
522                         local_refs = NULL;
523                         tail = &local_refs;
524                         remote_head = copy_ref(find_remote_branch(refs, option_branch));
525                 }
526
527                 if (!remote_head && option_branch)
528                         warning(_("Could not find remote branch %s to clone."),
529                                 option_branch);
530                 else {
531                         get_fetch_map(remote_head, refspec, &tail, 0);
532
533                         /* if --branch=tag, pull the requested tag explicitly */
534                         get_fetch_map(remote_head, tag_refspec, &tail, 0);
535                 }
536         } else
537                 get_fetch_map(refs, refspec, &tail, 0);
538
539         if (!option_mirror && !option_single_branch)
540                 get_fetch_map(refs, tag_refspec, &tail, 0);
541
542         return local_refs;
543 }
544
545 static void write_remote_refs(const struct ref *local_refs)
546 {
547         const struct ref *r;
548
549         struct ref_transaction *t;
550         struct strbuf err = STRBUF_INIT;
551
552         t = ref_transaction_begin(&err);
553         if (!t)
554                 die("%s", err.buf);
555
556         for (r = local_refs; r; r = r->next) {
557                 if (!r->peer_ref)
558                         continue;
559                 if (ref_transaction_create(t, r->peer_ref->name, r->old_oid.hash,
560                                            0, NULL, &err))
561                         die("%s", err.buf);
562         }
563
564         if (initial_ref_transaction_commit(t, &err))
565                 die("%s", err.buf);
566
567         strbuf_release(&err);
568         ref_transaction_free(t);
569 }
570
571 static void write_followtags(const struct ref *refs, const char *msg)
572 {
573         const struct ref *ref;
574         for (ref = refs; ref; ref = ref->next) {
575                 if (!starts_with(ref->name, "refs/tags/"))
576                         continue;
577                 if (ends_with(ref->name, "^{}"))
578                         continue;
579                 if (!has_object_file(&ref->old_oid))
580                         continue;
581                 update_ref(msg, ref->name, ref->old_oid.hash,
582                            NULL, 0, UPDATE_REFS_DIE_ON_ERR);
583         }
584 }
585
586 static int iterate_ref_map(void *cb_data, unsigned char sha1[20])
587 {
588         struct ref **rm = cb_data;
589         struct ref *ref = *rm;
590
591         /*
592          * Skip anything missing a peer_ref, which we are not
593          * actually going to write a ref for.
594          */
595         while (ref && !ref->peer_ref)
596                 ref = ref->next;
597         /* Returning -1 notes "end of list" to the caller. */
598         if (!ref)
599                 return -1;
600
601         hashcpy(sha1, ref->old_oid.hash);
602         *rm = ref->next;
603         return 0;
604 }
605
606 static void update_remote_refs(const struct ref *refs,
607                                const struct ref *mapped_refs,
608                                const struct ref *remote_head_points_at,
609                                const char *branch_top,
610                                const char *msg,
611                                struct transport *transport,
612                                int check_connectivity)
613 {
614         const struct ref *rm = mapped_refs;
615
616         if (check_connectivity) {
617                 struct check_connected_options opt = CHECK_CONNECTED_INIT;
618
619                 opt.transport = transport;
620                 opt.progress = transport->progress;
621
622                 if (check_connected(iterate_ref_map, &rm, &opt))
623                         die(_("remote did not send all necessary objects"));
624         }
625
626         if (refs) {
627                 write_remote_refs(mapped_refs);
628                 if (option_single_branch)
629                         write_followtags(refs, msg);
630         }
631
632         if (remote_head_points_at && !option_bare) {
633                 struct strbuf head_ref = STRBUF_INIT;
634                 strbuf_addstr(&head_ref, branch_top);
635                 strbuf_addstr(&head_ref, "HEAD");
636                 if (create_symref(head_ref.buf,
637                                   remote_head_points_at->peer_ref->name,
638                                   msg) < 0)
639                         die(_("unable to update %s"), head_ref.buf);
640                 strbuf_release(&head_ref);
641         }
642 }
643
644 static void update_head(const struct ref *our, const struct ref *remote,
645                         const char *msg)
646 {
647         const char *head;
648         if (our && skip_prefix(our->name, "refs/heads/", &head)) {
649                 /* Local default branch link */
650                 if (create_symref("HEAD", our->name, NULL) < 0)
651                         die(_("unable to update HEAD"));
652                 if (!option_bare) {
653                         update_ref(msg, "HEAD", our->old_oid.hash, 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_oid.hash);
659                 /* --branch specifies a non-branch (i.e. tags), detach HEAD */
660                 update_ref(msg, "HEAD", c->object.oid.hash,
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_oid.hash,
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                 struct argv_array args = ARGV_ARRAY_INIT;
729                 argv_array_pushl(&args, "submodule", "update", "--init", "--recursive", NULL);
730
731                 if (option_shallow_submodules == 1)
732                         argv_array_push(&args, "--depth=1");
733
734                 if (max_jobs != -1)
735                         argv_array_pushf(&args, "--jobs=%d", max_jobs);
736
737                 err = run_command_v_opt(args.argv, RUN_GIT_CMD);
738                 argv_array_clear(&args);
739         }
740
741         return err;
742 }
743
744 static int write_one_config(const char *key, const char *value, void *data)
745 {
746         return git_config_set_multivar_gently(key, value ? value : "true", "^$", 0);
747 }
748
749 static void write_config(struct string_list *config)
750 {
751         int i;
752
753         for (i = 0; i < config->nr; i++) {
754                 if (git_config_parse_parameter(config->items[i].string,
755                                                write_one_config, NULL) < 0)
756                         die(_("unable to write parameters to config file"));
757         }
758 }
759
760 static void write_refspec_config(const char *src_ref_prefix,
761                 const struct ref *our_head_points_at,
762                 const struct ref *remote_head_points_at,
763                 struct strbuf *branch_top)
764 {
765         struct strbuf key = STRBUF_INIT;
766         struct strbuf value = STRBUF_INIT;
767
768         if (option_mirror || !option_bare) {
769                 if (option_single_branch && !option_mirror) {
770                         if (option_branch) {
771                                 if (starts_with(our_head_points_at->name, "refs/tags/"))
772                                         strbuf_addf(&value, "+%s:%s", our_head_points_at->name,
773                                                 our_head_points_at->name);
774                                 else
775                                         strbuf_addf(&value, "+%s:%s%s", our_head_points_at->name,
776                                                 branch_top->buf, option_branch);
777                         } else if (remote_head_points_at) {
778                                 const char *head = remote_head_points_at->name;
779                                 if (!skip_prefix(head, "refs/heads/", &head))
780                                         die("BUG: remote HEAD points at non-head?");
781
782                                 strbuf_addf(&value, "+%s:%s%s", remote_head_points_at->name,
783                                                 branch_top->buf, head);
784                         }
785                         /*
786                          * otherwise, the next "git fetch" will
787                          * simply fetch from HEAD without updating
788                          * any remote-tracking branch, which is what
789                          * we want.
790                          */
791                 } else {
792                         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top->buf);
793                 }
794                 /* Configure the remote */
795                 if (value.len) {
796                         strbuf_addf(&key, "remote.%s.fetch", option_origin);
797                         git_config_set_multivar(key.buf, value.buf, "^$", 0);
798                         strbuf_reset(&key);
799
800                         if (option_mirror) {
801                                 strbuf_addf(&key, "remote.%s.mirror", option_origin);
802                                 git_config_set(key.buf, "true");
803                                 strbuf_reset(&key);
804                         }
805                 }
806         }
807
808         strbuf_release(&key);
809         strbuf_release(&value);
810 }
811
812 static void dissociate_from_references(void)
813 {
814         static const char* argv[] = { "repack", "-a", "-d", NULL };
815         char *alternates = git_pathdup("objects/info/alternates");
816
817         if (!access(alternates, F_OK)) {
818                 if (run_command_v_opt(argv, RUN_GIT_CMD|RUN_COMMAND_NO_STDIN))
819                         die(_("cannot repack to clean up"));
820                 if (unlink(alternates) && errno != ENOENT)
821                         die_errno(_("cannot unlink temporary alternates file"));
822         }
823         free(alternates);
824 }
825
826 int cmd_clone(int argc, const char **argv, const char *prefix)
827 {
828         int is_bundle = 0, is_local;
829         struct stat buf;
830         const char *repo_name, *repo, *work_tree, *git_dir;
831         char *path, *dir;
832         int dest_exists;
833         const struct ref *refs, *remote_head;
834         const struct ref *remote_head_points_at;
835         const struct ref *our_head_points_at;
836         struct ref *mapped_refs;
837         const struct ref *ref;
838         struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
839         struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
840         struct transport *transport = NULL;
841         const char *src_ref_prefix = "refs/heads/";
842         struct remote *remote;
843         int err = 0, complete_refs_before_fetch = 1;
844
845         struct refspec *refspec;
846         const char *fetch_pattern;
847
848         packet_trace_identity("clone");
849         argc = parse_options(argc, argv, prefix, builtin_clone_options,
850                              builtin_clone_usage, 0);
851
852         if (argc > 2)
853                 usage_msg_opt(_("Too many arguments."),
854                         builtin_clone_usage, builtin_clone_options);
855
856         if (argc == 0)
857                 usage_msg_opt(_("You must specify a repository to clone."),
858                         builtin_clone_usage, builtin_clone_options);
859
860         if (option_single_branch == -1)
861                 option_single_branch = option_depth ? 1 : 0;
862
863         if (option_mirror)
864                 option_bare = 1;
865
866         if (option_bare) {
867                 if (option_origin)
868                         die(_("--bare and --origin %s options are incompatible."),
869                             option_origin);
870                 if (real_git_dir)
871                         die(_("--bare and --separate-git-dir are incompatible."));
872                 option_no_checkout = 1;
873         }
874
875         if (!option_origin)
876                 option_origin = "origin";
877
878         repo_name = argv[0];
879
880         path = get_repo_path(repo_name, &is_bundle);
881         if (path)
882                 repo = xstrdup(absolute_path(repo_name));
883         else if (!strchr(repo_name, ':'))
884                 die(_("repository '%s' does not exist"), repo_name);
885         else
886                 repo = repo_name;
887
888         /* no need to be strict, transport_set_option() will validate it again */
889         if (option_depth && atoi(option_depth) < 1)
890                 die(_("depth %s is not a positive number"), option_depth);
891
892         if (argc == 2)
893                 dir = xstrdup(argv[1]);
894         else
895                 dir = guess_dir_name(repo_name, is_bundle, option_bare);
896         strip_trailing_slashes(dir);
897
898         dest_exists = !stat(dir, &buf);
899         if (dest_exists && !is_empty_dir(dir))
900                 die(_("destination path '%s' already exists and is not "
901                         "an empty directory."), dir);
902
903         strbuf_addf(&reflog_msg, "clone: from %s", repo);
904
905         if (option_bare)
906                 work_tree = NULL;
907         else {
908                 work_tree = getenv("GIT_WORK_TREE");
909                 if (work_tree && !stat(work_tree, &buf))
910                         die(_("working tree '%s' already exists."), work_tree);
911         }
912
913         if (option_bare || work_tree)
914                 git_dir = xstrdup(dir);
915         else {
916                 work_tree = dir;
917                 git_dir = mkpathdup("%s/.git", dir);
918         }
919
920         atexit(remove_junk);
921         sigchain_push_common(remove_junk_on_signal);
922
923         if (!option_bare) {
924                 if (safe_create_leading_directories_const(work_tree) < 0)
925                         die_errno(_("could not create leading directories of '%s'"),
926                                   work_tree);
927                 if (!dest_exists && mkdir(work_tree, 0777))
928                         die_errno(_("could not create work tree dir '%s'"),
929                                   work_tree);
930                 junk_work_tree = work_tree;
931                 set_git_work_tree(work_tree);
932         }
933
934         junk_git_dir = git_dir;
935         if (safe_create_leading_directories_const(git_dir) < 0)
936                 die(_("could not create leading directories of '%s'"), git_dir);
937
938         set_git_dir_init(git_dir, real_git_dir, 0);
939         if (real_git_dir) {
940                 git_dir = real_git_dir;
941                 junk_git_dir = real_git_dir;
942         }
943
944         if (0 <= option_verbosity) {
945                 if (option_bare)
946                         fprintf(stderr, _("Cloning into bare repository '%s'...\n"), dir);
947                 else
948                         fprintf(stderr, _("Cloning into '%s'...\n"), dir);
949         }
950         init_db(option_template, INIT_DB_QUIET);
951         write_config(&option_config);
952
953         git_config(git_default_config, NULL);
954
955         if (option_bare) {
956                 if (option_mirror)
957                         src_ref_prefix = "refs/";
958                 strbuf_addstr(&branch_top, src_ref_prefix);
959
960                 git_config_set("core.bare", "true");
961         } else {
962                 strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
963         }
964
965         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
966         strbuf_addf(&key, "remote.%s.url", option_origin);
967         git_config_set(key.buf, repo);
968         strbuf_reset(&key);
969
970         if (option_required_reference.nr || option_optional_reference.nr)
971                 setup_reference();
972
973         fetch_pattern = value.buf;
974         refspec = parse_fetch_refspec(1, &fetch_pattern);
975
976         strbuf_reset(&value);
977
978         remote = remote_get(option_origin);
979         transport = transport_get(remote, remote->url[0]);
980         transport_set_verbosity(transport, option_verbosity, option_progress);
981         transport->family = family;
982
983         path = get_repo_path(remote->url[0], &is_bundle);
984         is_local = option_local != 0 && path && !is_bundle;
985         if (is_local) {
986                 if (option_depth)
987                         warning(_("--depth is ignored in local clones; use file:// instead."));
988                 if (!access(mkpath("%s/shallow", path), F_OK)) {
989                         if (option_local > 0)
990                                 warning(_("source repository is shallow, ignoring --local"));
991                         is_local = 0;
992                 }
993         }
994         if (option_local > 0 && !is_local)
995                 warning(_("--local is ignored"));
996         transport->cloning = 1;
997
998         if (!transport->get_refs_list || (!is_local && !transport->fetch))
999                 die(_("Don't know how to clone %s"), transport->url);
1000
1001         transport_set_option(transport, TRANS_OPT_KEEP, "yes");
1002
1003         if (option_depth)
1004                 transport_set_option(transport, TRANS_OPT_DEPTH,
1005                                      option_depth);
1006         if (option_single_branch)
1007                 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
1008
1009         if (option_upload_pack)
1010                 transport_set_option(transport, TRANS_OPT_UPLOADPACK,
1011                                      option_upload_pack);
1012
1013         if (transport->smart_options && !option_depth)
1014                 transport->smart_options->check_self_contained_and_connected = 1;
1015
1016         refs = transport_get_remote_refs(transport);
1017
1018         if (refs) {
1019                 mapped_refs = wanted_peer_refs(refs, refspec);
1020                 /*
1021                  * transport_get_remote_refs() may return refs with null sha-1
1022                  * in mapped_refs (see struct transport->get_refs_list
1023                  * comment). In that case we need fetch it early because
1024                  * remote_head code below relies on it.
1025                  *
1026                  * for normal clones, transport_get_remote_refs() should
1027                  * return reliable ref set, we can delay cloning until after
1028                  * remote HEAD check.
1029                  */
1030                 for (ref = refs; ref; ref = ref->next)
1031                         if (is_null_oid(&ref->old_oid)) {
1032                                 complete_refs_before_fetch = 0;
1033                                 break;
1034                         }
1035
1036                 if (!is_local && !complete_refs_before_fetch)
1037                         transport_fetch_refs(transport, mapped_refs);
1038
1039                 remote_head = find_ref_by_name(refs, "HEAD");
1040                 remote_head_points_at =
1041                         guess_remote_head(remote_head, mapped_refs, 0);
1042
1043                 if (option_branch) {
1044                         our_head_points_at =
1045                                 find_remote_branch(mapped_refs, option_branch);
1046
1047                         if (!our_head_points_at)
1048                                 die(_("Remote branch %s not found in upstream %s"),
1049                                     option_branch, option_origin);
1050                 }
1051                 else
1052                         our_head_points_at = remote_head_points_at;
1053         }
1054         else {
1055                 if (option_branch)
1056                         die(_("Remote branch %s not found in upstream %s"),
1057                                         option_branch, option_origin);
1058
1059                 warning(_("You appear to have cloned an empty repository."));
1060                 mapped_refs = NULL;
1061                 our_head_points_at = NULL;
1062                 remote_head_points_at = NULL;
1063                 remote_head = NULL;
1064                 option_no_checkout = 1;
1065                 if (!option_bare)
1066                         install_branch_config(0, "master", option_origin,
1067                                               "refs/heads/master");
1068         }
1069
1070         write_refspec_config(src_ref_prefix, our_head_points_at,
1071                         remote_head_points_at, &branch_top);
1072
1073         if (is_local)
1074                 clone_local(path, git_dir);
1075         else if (refs && complete_refs_before_fetch)
1076                 transport_fetch_refs(transport, mapped_refs);
1077
1078         update_remote_refs(refs, mapped_refs, remote_head_points_at,
1079                            branch_top.buf, reflog_msg.buf, transport, !is_local);
1080
1081         update_head(our_head_points_at, remote_head, reflog_msg.buf);
1082
1083         transport_unlock_pack(transport);
1084         transport_disconnect(transport);
1085
1086         if (option_dissociate) {
1087                 close_all_packs();
1088                 dissociate_from_references();
1089         }
1090
1091         junk_mode = JUNK_LEAVE_REPO;
1092         err = checkout();
1093
1094         strbuf_release(&reflog_msg);
1095         strbuf_release(&branch_top);
1096         strbuf_release(&key);
1097         strbuf_release(&value);
1098         junk_mode = JUNK_LEAVE_ALL;
1099
1100         free(refspec);
1101         return err;
1102 }