Sync with 2.7.3
[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 enum transport_family family;
51 static struct string_list option_config;
52 static struct string_list option_reference;
53 static int option_dissociate;
54
55 static struct option builtin_clone_options[] = {
56         OPT__VERBOSITY(&option_verbosity),
57         OPT_BOOL(0, "progress", &option_progress,
58                  N_("force progress reporting")),
59         OPT_BOOL('n', "no-checkout", &option_no_checkout,
60                  N_("don't create a checkout")),
61         OPT_BOOL(0, "bare", &option_bare, N_("create a bare repository")),
62         OPT_HIDDEN_BOOL(0, "naked", &option_bare,
63                         N_("create a bare repository")),
64         OPT_BOOL(0, "mirror", &option_mirror,
65                  N_("create a mirror repository (implies bare)")),
66         OPT_BOOL('l', "local", &option_local,
67                 N_("to clone from a local repository")),
68         OPT_BOOL(0, "no-hardlinks", &option_no_hardlinks,
69                     N_("don't use local hardlinks, always copy")),
70         OPT_BOOL('s', "shared", &option_shared,
71                     N_("setup as shared repository")),
72         OPT_BOOL(0, "recursive", &option_recursive,
73                     N_("initialize submodules in the clone")),
74         OPT_BOOL(0, "recurse-submodules", &option_recursive,
75                     N_("initialize submodules in the clone")),
76         OPT_STRING(0, "template", &option_template, N_("template-directory"),
77                    N_("directory from which templates will be used")),
78         OPT_STRING_LIST(0, "reference", &option_reference, N_("repo"),
79                         N_("reference repository")),
80         OPT_BOOL(0, "dissociate", &option_dissociate,
81                  N_("use --reference only while cloning")),
82         OPT_STRING('o', "origin", &option_origin, N_("name"),
83                    N_("use <name> instead of 'origin' to track upstream")),
84         OPT_STRING('b', "branch", &option_branch, N_("branch"),
85                    N_("checkout <branch> instead of the remote's HEAD")),
86         OPT_STRING('u', "upload-pack", &option_upload_pack, N_("path"),
87                    N_("path to git-upload-pack on the remote")),
88         OPT_STRING(0, "depth", &option_depth, N_("depth"),
89                     N_("create a shallow clone of that depth")),
90         OPT_BOOL(0, "single-branch", &option_single_branch,
91                     N_("clone only one branch, HEAD or --branch")),
92         OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
93                    N_("separate git dir from working tree")),
94         OPT_STRING_LIST('c', "config", &option_config, N_("key=value"),
95                         N_("set config inside the new repository")),
96         OPT_SET_INT('4', "ipv4", &family, N_("use IPv4 addresses only"),
97                         TRANSPORT_FAMILY_IPV4),
98         OPT_SET_INT('6', "ipv6", &family, N_("use IPv6 addresses only"),
99                         TRANSPORT_FAMILY_IPV6),
100         OPT_END()
101 };
102
103 static const char *argv_submodule[] = {
104         "submodule", "update", "--init", "--recursive", NULL
105 };
106
107 static const char *get_repo_path_1(struct strbuf *path, int *is_bundle)
108 {
109         static char *suffix[] = { "/.git", "", ".git/.git", ".git" };
110         static char *bundle_suffix[] = { ".bundle", "" };
111         size_t baselen = path->len;
112         struct stat st;
113         int i;
114
115         for (i = 0; i < ARRAY_SIZE(suffix); i++) {
116                 strbuf_setlen(path, baselen);
117                 strbuf_addstr(path, suffix[i]);
118                 if (stat(path->buf, &st))
119                         continue;
120                 if (S_ISDIR(st.st_mode) && is_git_directory(path->buf)) {
121                         *is_bundle = 0;
122                         return path->buf;
123                 } else if (S_ISREG(st.st_mode) && st.st_size > 8) {
124                         /* Is it a "gitfile"? */
125                         char signature[8];
126                         const char *dst;
127                         int len, fd = open(path->buf, O_RDONLY);
128                         if (fd < 0)
129                                 continue;
130                         len = read_in_full(fd, signature, 8);
131                         close(fd);
132                         if (len != 8 || strncmp(signature, "gitdir: ", 8))
133                                 continue;
134                         dst = read_gitfile(path->buf);
135                         if (dst) {
136                                 *is_bundle = 0;
137                                 return dst;
138                         }
139                 }
140         }
141
142         for (i = 0; i < ARRAY_SIZE(bundle_suffix); i++) {
143                 strbuf_setlen(path, baselen);
144                 strbuf_addstr(path, bundle_suffix[i]);
145                 if (!stat(path->buf, &st) && S_ISREG(st.st_mode)) {
146                         *is_bundle = 1;
147                         return path->buf;
148                 }
149         }
150
151         return NULL;
152 }
153
154 static char *get_repo_path(const char *repo, int *is_bundle)
155 {
156         struct strbuf path = STRBUF_INIT;
157         const char *raw;
158         char *canon;
159
160         strbuf_addstr(&path, repo);
161         raw = get_repo_path_1(&path, is_bundle);
162         canon = raw ? xstrdup(absolute_path(raw)) : NULL;
163         strbuf_release(&path);
164         return canon;
165 }
166
167 static char *guess_dir_name(const char *repo, int is_bundle, int is_bare)
168 {
169         const char *end = repo + strlen(repo), *start, *ptr;
170         size_t len;
171         char *dir;
172
173         /*
174          * Skip scheme.
175          */
176         start = strstr(repo, "://");
177         if (start == NULL)
178                 start = repo;
179         else
180                 start += 3;
181
182         /*
183          * Skip authentication data. The stripping does happen
184          * greedily, such that we strip up to the last '@' inside
185          * the host part.
186          */
187         for (ptr = start; ptr < end && !is_dir_sep(*ptr); ptr++) {
188                 if (*ptr == '@')
189                         start = ptr + 1;
190         }
191
192         /*
193          * Strip trailing spaces, slashes and /.git
194          */
195         while (start < end && (is_dir_sep(end[-1]) || isspace(end[-1])))
196                 end--;
197         if (end - start > 5 && is_dir_sep(end[-5]) &&
198             !strncmp(end - 4, ".git", 4)) {
199                 end -= 5;
200                 while (start < end && is_dir_sep(end[-1]))
201                         end--;
202         }
203
204         /*
205          * Strip trailing port number if we've got only a
206          * hostname (that is, there is no dir separator but a
207          * colon). This check is required such that we do not
208          * strip URI's like '/foo/bar:2222.git', which should
209          * result in a dir '2222' being guessed due to backwards
210          * compatibility.
211          */
212         if (memchr(start, '/', end - start) == NULL
213             && memchr(start, ':', end - start) != NULL) {
214                 ptr = end;
215                 while (start < ptr && isdigit(ptr[-1]) && ptr[-1] != ':')
216                         ptr--;
217                 if (start < ptr && ptr[-1] == ':')
218                         end = ptr - 1;
219         }
220
221         /*
222          * Find last component. To remain backwards compatible we
223          * also regard colons as path separators, such that
224          * cloning a repository 'foo:bar.git' would result in a
225          * directory 'bar' being guessed.
226          */
227         ptr = end;
228         while (start < ptr && !is_dir_sep(ptr[-1]) && ptr[-1] != ':')
229                 ptr--;
230         start = ptr;
231
232         /*
233          * Strip .{bundle,git}.
234          */
235         len = end - start;
236         strip_suffix_mem(start, &len, is_bundle ? ".bundle" : ".git");
237
238         if (!len || (len == 1 && *start == '/'))
239                 die(_("No directory name could be guessed.\n"
240                       "Please specify a directory on the command line"));
241
242         if (is_bare)
243                 dir = xstrfmt("%.*s.git", (int)len, start);
244         else
245                 dir = xstrndup(start, len);
246         /*
247          * Replace sequences of 'control' characters and whitespace
248          * with one ascii space, remove leading and trailing spaces.
249          */
250         if (*dir) {
251                 char *out = dir;
252                 int prev_space = 1 /* strip leading whitespace */;
253                 for (end = dir; *end; ++end) {
254                         char ch = *end;
255                         if ((unsigned char)ch < '\x20')
256                                 ch = '\x20';
257                         if (isspace(ch)) {
258                                 if (prev_space)
259                                         continue;
260                                 prev_space = 1;
261                         } else
262                                 prev_space = 0;
263                         *out++ = ch;
264                 }
265                 *out = '\0';
266                 if (out > dir && prev_space)
267                         out[-1] = '\0';
268         }
269         return dir;
270 }
271
272 static void strip_trailing_slashes(char *dir)
273 {
274         char *end = dir + strlen(dir);
275
276         while (dir < end - 1 && is_dir_sep(end[-1]))
277                 end--;
278         *end = '\0';
279 }
280
281 static int add_one_reference(struct string_list_item *item, void *cb_data)
282 {
283         char *ref_git;
284         const char *repo;
285         struct strbuf alternate = STRBUF_INIT;
286
287         /* Beware: read_gitfile(), real_path() and mkpath() return static buffer */
288         ref_git = xstrdup(real_path(item->string));
289
290         repo = read_gitfile(ref_git);
291         if (!repo)
292                 repo = read_gitfile(mkpath("%s/.git", ref_git));
293         if (repo) {
294                 free(ref_git);
295                 ref_git = xstrdup(repo);
296         }
297
298         if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
299                 char *ref_git_git = mkpathdup("%s/.git", ref_git);
300                 free(ref_git);
301                 ref_git = ref_git_git;
302         } else if (!is_directory(mkpath("%s/objects", ref_git))) {
303                 struct strbuf sb = STRBUF_INIT;
304                 if (get_common_dir(&sb, ref_git))
305                         die(_("reference repository '%s' as a linked checkout is not supported yet."),
306                             item->string);
307                 die(_("reference repository '%s' is not a local repository."),
308                     item->string);
309         }
310
311         if (!access(mkpath("%s/shallow", ref_git), F_OK))
312                 die(_("reference repository '%s' is shallow"), item->string);
313
314         if (!access(mkpath("%s/info/grafts", ref_git), F_OK))
315                 die(_("reference repository '%s' is grafted"), item->string);
316
317         strbuf_addf(&alternate, "%s/objects", ref_git);
318         add_to_alternates_file(alternate.buf);
319         strbuf_release(&alternate);
320         free(ref_git);
321         return 0;
322 }
323
324 static void setup_reference(void)
325 {
326         for_each_string_list(&option_reference, add_one_reference, NULL);
327 }
328
329 static void copy_alternates(struct strbuf *src, struct strbuf *dst,
330                             const char *src_repo)
331 {
332         /*
333          * Read from the source objects/info/alternates file
334          * and copy the entries to corresponding file in the
335          * destination repository with add_to_alternates_file().
336          * Both src and dst have "$path/objects/info/alternates".
337          *
338          * Instead of copying bit-for-bit from the original,
339          * we need to append to existing one so that the already
340          * created entry via "clone -s" is not lost, and also
341          * to turn entries with paths relative to the original
342          * absolute, so that they can be used in the new repository.
343          */
344         FILE *in = fopen(src->buf, "r");
345         struct strbuf line = STRBUF_INIT;
346
347         while (strbuf_getline(&line, in) != EOF) {
348                 char *abs_path;
349                 if (!line.len || line.buf[0] == '#')
350                         continue;
351                 if (is_absolute_path(line.buf)) {
352                         add_to_alternates_file(line.buf);
353                         continue;
354                 }
355                 abs_path = mkpathdup("%s/objects/%s", src_repo, line.buf);
356                 normalize_path_copy(abs_path, abs_path);
357                 add_to_alternates_file(abs_path);
358                 free(abs_path);
359         }
360         strbuf_release(&line);
361         fclose(in);
362 }
363
364 static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
365                                    const char *src_repo, int src_baselen)
366 {
367         struct dirent *de;
368         struct stat buf;
369         int src_len, dest_len;
370         DIR *dir;
371
372         dir = opendir(src->buf);
373         if (!dir)
374                 die_errno(_("failed to open '%s'"), src->buf);
375
376         if (mkdir(dest->buf, 0777)) {
377                 if (errno != EEXIST)
378                         die_errno(_("failed to create directory '%s'"), dest->buf);
379                 else if (stat(dest->buf, &buf))
380                         die_errno(_("failed to stat '%s'"), dest->buf);
381                 else if (!S_ISDIR(buf.st_mode))
382                         die(_("%s exists and is not a directory"), dest->buf);
383         }
384
385         strbuf_addch(src, '/');
386         src_len = src->len;
387         strbuf_addch(dest, '/');
388         dest_len = dest->len;
389
390         while ((de = readdir(dir)) != NULL) {
391                 strbuf_setlen(src, src_len);
392                 strbuf_addstr(src, de->d_name);
393                 strbuf_setlen(dest, dest_len);
394                 strbuf_addstr(dest, de->d_name);
395                 if (stat(src->buf, &buf)) {
396                         warning (_("failed to stat %s\n"), src->buf);
397                         continue;
398                 }
399                 if (S_ISDIR(buf.st_mode)) {
400                         if (de->d_name[0] != '.')
401                                 copy_or_link_directory(src, dest,
402                                                        src_repo, src_baselen);
403                         continue;
404                 }
405
406                 /* Files that cannot be copied bit-for-bit... */
407                 if (!strcmp(src->buf + src_baselen, "/info/alternates")) {
408                         copy_alternates(src, dest, src_repo);
409                         continue;
410                 }
411
412                 if (unlink(dest->buf) && errno != ENOENT)
413                         die_errno(_("failed to unlink '%s'"), dest->buf);
414                 if (!option_no_hardlinks) {
415                         if (!link(src->buf, dest->buf))
416                                 continue;
417                         if (option_local > 0)
418                                 die_errno(_("failed to create link '%s'"), dest->buf);
419                         option_no_hardlinks = 1;
420                 }
421                 if (copy_file_with_time(dest->buf, src->buf, 0666))
422                         die_errno(_("failed to copy file to '%s'"), dest->buf);
423         }
424         closedir(dir);
425 }
426
427 static void clone_local(const char *src_repo, const char *dest_repo)
428 {
429         if (option_shared) {
430                 struct strbuf alt = STRBUF_INIT;
431                 strbuf_addf(&alt, "%s/objects", src_repo);
432                 add_to_alternates_file(alt.buf);
433                 strbuf_release(&alt);
434         } else {
435                 struct strbuf src = STRBUF_INIT;
436                 struct strbuf dest = STRBUF_INIT;
437                 get_common_dir(&src, src_repo);
438                 get_common_dir(&dest, dest_repo);
439                 strbuf_addstr(&src, "/objects");
440                 strbuf_addstr(&dest, "/objects");
441                 copy_or_link_directory(&src, &dest, src_repo, src.len);
442                 strbuf_release(&src);
443                 strbuf_release(&dest);
444         }
445
446         if (0 <= option_verbosity)
447                 fprintf(stderr, _("done.\n"));
448 }
449
450 static const char *junk_work_tree;
451 static const char *junk_git_dir;
452 static enum {
453         JUNK_LEAVE_NONE,
454         JUNK_LEAVE_REPO,
455         JUNK_LEAVE_ALL
456 } junk_mode = JUNK_LEAVE_NONE;
457
458 static const char junk_leave_repo_msg[] =
459 N_("Clone succeeded, but checkout failed.\n"
460    "You can inspect what was checked out with 'git status'\n"
461    "and retry the checkout with 'git checkout -f HEAD'\n");
462
463 static void remove_junk(void)
464 {
465         struct strbuf sb = STRBUF_INIT;
466
467         switch (junk_mode) {
468         case JUNK_LEAVE_REPO:
469                 warning("%s", _(junk_leave_repo_msg));
470                 /* fall-through */
471         case JUNK_LEAVE_ALL:
472                 return;
473         default:
474                 /* proceed to removal */
475                 break;
476         }
477
478         if (junk_git_dir) {
479                 strbuf_addstr(&sb, junk_git_dir);
480                 remove_dir_recursively(&sb, 0);
481                 strbuf_reset(&sb);
482         }
483         if (junk_work_tree) {
484                 strbuf_addstr(&sb, junk_work_tree);
485                 remove_dir_recursively(&sb, 0);
486                 strbuf_reset(&sb);
487         }
488 }
489
490 static void remove_junk_on_signal(int signo)
491 {
492         remove_junk();
493         sigchain_pop(signo);
494         raise(signo);
495 }
496
497 static struct ref *find_remote_branch(const struct ref *refs, const char *branch)
498 {
499         struct ref *ref;
500         struct strbuf head = STRBUF_INIT;
501         strbuf_addstr(&head, "refs/heads/");
502         strbuf_addstr(&head, branch);
503         ref = find_ref_by_name(refs, head.buf);
504         strbuf_release(&head);
505
506         if (ref)
507                 return ref;
508
509         strbuf_addstr(&head, "refs/tags/");
510         strbuf_addstr(&head, branch);
511         ref = find_ref_by_name(refs, head.buf);
512         strbuf_release(&head);
513
514         return ref;
515 }
516
517 static struct ref *wanted_peer_refs(const struct ref *refs,
518                 struct refspec *refspec)
519 {
520         struct ref *head = copy_ref(find_ref_by_name(refs, "HEAD"));
521         struct ref *local_refs = head;
522         struct ref **tail = head ? &head->next : &local_refs;
523
524         if (option_single_branch) {
525                 struct ref *remote_head = NULL;
526
527                 if (!option_branch)
528                         remote_head = guess_remote_head(head, refs, 0);
529                 else {
530                         local_refs = NULL;
531                         tail = &local_refs;
532                         remote_head = copy_ref(find_remote_branch(refs, option_branch));
533                 }
534
535                 if (!remote_head && option_branch)
536                         warning(_("Could not find remote branch %s to clone."),
537                                 option_branch);
538                 else {
539                         get_fetch_map(remote_head, refspec, &tail, 0);
540
541                         /* if --branch=tag, pull the requested tag explicitly */
542                         get_fetch_map(remote_head, tag_refspec, &tail, 0);
543                 }
544         } else
545                 get_fetch_map(refs, refspec, &tail, 0);
546
547         if (!option_mirror && !option_single_branch)
548                 get_fetch_map(refs, tag_refspec, &tail, 0);
549
550         return local_refs;
551 }
552
553 static void write_remote_refs(const struct ref *local_refs)
554 {
555         const struct ref *r;
556
557         struct ref_transaction *t;
558         struct strbuf err = STRBUF_INIT;
559
560         t = ref_transaction_begin(&err);
561         if (!t)
562                 die("%s", err.buf);
563
564         for (r = local_refs; r; r = r->next) {
565                 if (!r->peer_ref)
566                         continue;
567                 if (ref_transaction_create(t, r->peer_ref->name, r->old_oid.hash,
568                                            0, NULL, &err))
569                         die("%s", err.buf);
570         }
571
572         if (initial_ref_transaction_commit(t, &err))
573                 die("%s", err.buf);
574
575         strbuf_release(&err);
576         ref_transaction_free(t);
577 }
578
579 static void write_followtags(const struct ref *refs, const char *msg)
580 {
581         const struct ref *ref;
582         for (ref = refs; ref; ref = ref->next) {
583                 if (!starts_with(ref->name, "refs/tags/"))
584                         continue;
585                 if (ends_with(ref->name, "^{}"))
586                         continue;
587                 if (!has_object_file(&ref->old_oid))
588                         continue;
589                 update_ref(msg, ref->name, ref->old_oid.hash,
590                            NULL, 0, UPDATE_REFS_DIE_ON_ERR);
591         }
592 }
593
594 static int iterate_ref_map(void *cb_data, unsigned char sha1[20])
595 {
596         struct ref **rm = cb_data;
597         struct ref *ref = *rm;
598
599         /*
600          * Skip anything missing a peer_ref, which we are not
601          * actually going to write a ref for.
602          */
603         while (ref && !ref->peer_ref)
604                 ref = ref->next;
605         /* Returning -1 notes "end of list" to the caller. */
606         if (!ref)
607                 return -1;
608
609         hashcpy(sha1, ref->old_oid.hash);
610         *rm = ref->next;
611         return 0;
612 }
613
614 static void update_remote_refs(const struct ref *refs,
615                                const struct ref *mapped_refs,
616                                const struct ref *remote_head_points_at,
617                                const char *branch_top,
618                                const char *msg,
619                                struct transport *transport,
620                                int check_connectivity)
621 {
622         const struct ref *rm = mapped_refs;
623
624         if (check_connectivity) {
625                 if (transport->progress)
626                         fprintf(stderr, _("Checking connectivity... "));
627                 if (check_everything_connected_with_transport(iterate_ref_map,
628                                                               0, &rm, transport))
629                         die(_("remote did not send all necessary objects"));
630                 if (transport->progress)
631                         fprintf(stderr, _("done.\n"));
632         }
633
634         if (refs) {
635                 write_remote_refs(mapped_refs);
636                 if (option_single_branch)
637                         write_followtags(refs, msg);
638         }
639
640         if (remote_head_points_at && !option_bare) {
641                 struct strbuf head_ref = STRBUF_INIT;
642                 strbuf_addstr(&head_ref, branch_top);
643                 strbuf_addstr(&head_ref, "HEAD");
644                 if (create_symref(head_ref.buf,
645                                   remote_head_points_at->peer_ref->name,
646                                   msg) < 0)
647                         die(_("unable to update %s"), head_ref.buf);
648                 strbuf_release(&head_ref);
649         }
650 }
651
652 static void update_head(const struct ref *our, const struct ref *remote,
653                         const char *msg)
654 {
655         const char *head;
656         if (our && skip_prefix(our->name, "refs/heads/", &head)) {
657                 /* Local default branch link */
658                 if (create_symref("HEAD", our->name, NULL) < 0)
659                         die(_("unable to update HEAD"));
660                 if (!option_bare) {
661                         update_ref(msg, "HEAD", our->old_oid.hash, NULL, 0,
662                                    UPDATE_REFS_DIE_ON_ERR);
663                         install_branch_config(0, head, option_origin, our->name);
664                 }
665         } else if (our) {
666                 struct commit *c = lookup_commit_reference(our->old_oid.hash);
667                 /* --branch specifies a non-branch (i.e. tags), detach HEAD */
668                 update_ref(msg, "HEAD", c->object.oid.hash,
669                            NULL, REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
670         } else if (remote) {
671                 /*
672                  * We know remote HEAD points to a non-branch, or
673                  * HEAD points to a branch but we don't know which one.
674                  * Detach HEAD in all these cases.
675                  */
676                 update_ref(msg, "HEAD", remote->old_oid.hash,
677                            NULL, REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
678         }
679 }
680
681 static int checkout(void)
682 {
683         unsigned char sha1[20];
684         char *head;
685         struct lock_file *lock_file;
686         struct unpack_trees_options opts;
687         struct tree *tree;
688         struct tree_desc t;
689         int err = 0;
690
691         if (option_no_checkout)
692                 return 0;
693
694         head = resolve_refdup("HEAD", RESOLVE_REF_READING, sha1, NULL);
695         if (!head) {
696                 warning(_("remote HEAD refers to nonexistent ref, "
697                           "unable to checkout.\n"));
698                 return 0;
699         }
700         if (!strcmp(head, "HEAD")) {
701                 if (advice_detached_head)
702                         detach_advice(sha1_to_hex(sha1));
703         } else {
704                 if (!starts_with(head, "refs/heads/"))
705                         die(_("HEAD not found below refs/heads!"));
706         }
707         free(head);
708
709         /* We need to be in the new work tree for the checkout */
710         setup_work_tree();
711
712         lock_file = xcalloc(1, sizeof(struct lock_file));
713         hold_locked_index(lock_file, 1);
714
715         memset(&opts, 0, sizeof opts);
716         opts.update = 1;
717         opts.merge = 1;
718         opts.fn = oneway_merge;
719         opts.verbose_update = (option_verbosity >= 0);
720         opts.src_index = &the_index;
721         opts.dst_index = &the_index;
722
723         tree = parse_tree_indirect(sha1);
724         parse_tree(tree);
725         init_tree_desc(&t, tree->buffer, tree->size);
726         if (unpack_trees(1, &t, &opts) < 0)
727                 die(_("unable to checkout working tree"));
728
729         if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
730                 die(_("unable to write new index file"));
731
732         err |= run_hook_le(NULL, "post-checkout", sha1_to_hex(null_sha1),
733                            sha1_to_hex(sha1), "1", NULL);
734
735         if (!err && option_recursive)
736                 err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
737
738         return err;
739 }
740
741 static int write_one_config(const char *key, const char *value, void *data)
742 {
743         return git_config_set_multivar_gently(key, value ? value : "true", "^$", 0);
744 }
745
746 static void write_config(struct string_list *config)
747 {
748         int i;
749
750         for (i = 0; i < config->nr; i++) {
751                 if (git_config_parse_parameter(config->items[i].string,
752                                                write_one_config, NULL) < 0)
753                         die(_("unable to write parameters to config file"));
754         }
755 }
756
757 static void write_refspec_config(const char *src_ref_prefix,
758                 const struct ref *our_head_points_at,
759                 const struct ref *remote_head_points_at,
760                 struct strbuf *branch_top)
761 {
762         struct strbuf key = STRBUF_INIT;
763         struct strbuf value = STRBUF_INIT;
764
765         if (option_mirror || !option_bare) {
766                 if (option_single_branch && !option_mirror) {
767                         if (option_branch) {
768                                 if (starts_with(our_head_points_at->name, "refs/tags/"))
769                                         strbuf_addf(&value, "+%s:%s", our_head_points_at->name,
770                                                 our_head_points_at->name);
771                                 else
772                                         strbuf_addf(&value, "+%s:%s%s", our_head_points_at->name,
773                                                 branch_top->buf, option_branch);
774                         } else if (remote_head_points_at) {
775                                 const char *head = remote_head_points_at->name;
776                                 if (!skip_prefix(head, "refs/heads/", &head))
777                                         die("BUG: remote HEAD points at non-head?");
778
779                                 strbuf_addf(&value, "+%s:%s%s", remote_head_points_at->name,
780                                                 branch_top->buf, head);
781                         }
782                         /*
783                          * otherwise, the next "git fetch" will
784                          * simply fetch from HEAD without updating
785                          * any remote-tracking branch, which is what
786                          * we want.
787                          */
788                 } else {
789                         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top->buf);
790                 }
791                 /* Configure the remote */
792                 if (value.len) {
793                         strbuf_addf(&key, "remote.%s.fetch", option_origin);
794                         git_config_set_multivar(key.buf, value.buf, "^$", 0);
795                         strbuf_reset(&key);
796
797                         if (option_mirror) {
798                                 strbuf_addf(&key, "remote.%s.mirror", option_origin);
799                                 git_config_set(key.buf, "true");
800                                 strbuf_reset(&key);
801                         }
802                 }
803         }
804
805         strbuf_release(&key);
806         strbuf_release(&value);
807 }
808
809 static void dissociate_from_references(void)
810 {
811         static const char* argv[] = { "repack", "-a", "-d", NULL };
812         char *alternates = git_pathdup("objects/info/alternates");
813
814         if (!access(alternates, F_OK)) {
815                 if (run_command_v_opt(argv, RUN_GIT_CMD|RUN_COMMAND_NO_STDIN))
816                         die(_("cannot repack to clean up"));
817                 if (unlink(alternates) && errno != ENOENT)
818                         die_errno(_("cannot unlink temporary alternates file"));
819         }
820         free(alternates);
821 }
822
823 int cmd_clone(int argc, const char **argv, const char *prefix)
824 {
825         int is_bundle = 0, is_local;
826         struct stat buf;
827         const char *repo_name, *repo, *work_tree, *git_dir;
828         char *path, *dir;
829         int dest_exists;
830         const struct ref *refs, *remote_head;
831         const struct ref *remote_head_points_at;
832         const struct ref *our_head_points_at;
833         struct ref *mapped_refs;
834         const struct ref *ref;
835         struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
836         struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
837         struct transport *transport = NULL;
838         const char *src_ref_prefix = "refs/heads/";
839         struct remote *remote;
840         int err = 0, complete_refs_before_fetch = 1;
841
842         struct refspec *refspec;
843         const char *fetch_pattern;
844
845         packet_trace_identity("clone");
846         argc = parse_options(argc, argv, prefix, builtin_clone_options,
847                              builtin_clone_usage, 0);
848
849         if (argc > 2)
850                 usage_msg_opt(_("Too many arguments."),
851                         builtin_clone_usage, builtin_clone_options);
852
853         if (argc == 0)
854                 usage_msg_opt(_("You must specify a repository to clone."),
855                         builtin_clone_usage, builtin_clone_options);
856
857         if (option_single_branch == -1)
858                 option_single_branch = option_depth ? 1 : 0;
859
860         if (option_mirror)
861                 option_bare = 1;
862
863         if (option_bare) {
864                 if (option_origin)
865                         die(_("--bare and --origin %s options are incompatible."),
866                             option_origin);
867                 if (real_git_dir)
868                         die(_("--bare and --separate-git-dir are incompatible."));
869                 option_no_checkout = 1;
870         }
871
872         if (!option_origin)
873                 option_origin = "origin";
874
875         repo_name = argv[0];
876
877         path = get_repo_path(repo_name, &is_bundle);
878         if (path)
879                 repo = xstrdup(absolute_path(repo_name));
880         else if (!strchr(repo_name, ':'))
881                 die(_("repository '%s' does not exist"), repo_name);
882         else
883                 repo = repo_name;
884
885         /* no need to be strict, transport_set_option() will validate it again */
886         if (option_depth && atoi(option_depth) < 1)
887                 die(_("depth %s is not a positive number"), option_depth);
888
889         if (argc == 2)
890                 dir = xstrdup(argv[1]);
891         else
892                 dir = guess_dir_name(repo_name, is_bundle, option_bare);
893         strip_trailing_slashes(dir);
894
895         dest_exists = !stat(dir, &buf);
896         if (dest_exists && !is_empty_dir(dir))
897                 die(_("destination path '%s' already exists and is not "
898                         "an empty directory."), dir);
899
900         strbuf_addf(&reflog_msg, "clone: from %s", repo);
901
902         if (option_bare)
903                 work_tree = NULL;
904         else {
905                 work_tree = getenv("GIT_WORK_TREE");
906                 if (work_tree && !stat(work_tree, &buf))
907                         die(_("working tree '%s' already exists."), work_tree);
908         }
909
910         if (option_bare || work_tree)
911                 git_dir = xstrdup(dir);
912         else {
913                 work_tree = dir;
914                 git_dir = mkpathdup("%s/.git", dir);
915         }
916
917         atexit(remove_junk);
918         sigchain_push_common(remove_junk_on_signal);
919
920         if (!option_bare) {
921                 if (safe_create_leading_directories_const(work_tree) < 0)
922                         die_errno(_("could not create leading directories of '%s'"),
923                                   work_tree);
924                 if (!dest_exists && mkdir(work_tree, 0777))
925                         die_errno(_("could not create work tree dir '%s'"),
926                                   work_tree);
927                 junk_work_tree = work_tree;
928                 set_git_work_tree(work_tree);
929         }
930
931         junk_git_dir = git_dir;
932         if (safe_create_leading_directories_const(git_dir) < 0)
933                 die(_("could not create leading directories of '%s'"), git_dir);
934
935         set_git_dir_init(git_dir, real_git_dir, 0);
936         if (real_git_dir) {
937                 git_dir = real_git_dir;
938                 junk_git_dir = real_git_dir;
939         }
940
941         if (0 <= option_verbosity) {
942                 if (option_bare)
943                         fprintf(stderr, _("Cloning into bare repository '%s'...\n"), dir);
944                 else
945                         fprintf(stderr, _("Cloning into '%s'...\n"), dir);
946         }
947         init_db(option_template, INIT_DB_QUIET);
948         write_config(&option_config);
949
950         git_config(git_default_config, NULL);
951
952         if (option_bare) {
953                 if (option_mirror)
954                         src_ref_prefix = "refs/";
955                 strbuf_addstr(&branch_top, src_ref_prefix);
956
957                 git_config_set("core.bare", "true");
958         } else {
959                 strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
960         }
961
962         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
963         strbuf_addf(&key, "remote.%s.url", option_origin);
964         git_config_set(key.buf, repo);
965         strbuf_reset(&key);
966
967         if (option_reference.nr)
968                 setup_reference();
969
970         fetch_pattern = value.buf;
971         refspec = parse_fetch_refspec(1, &fetch_pattern);
972
973         strbuf_reset(&value);
974
975         remote = remote_get(option_origin);
976         transport = transport_get(remote, remote->url[0]);
977         transport_set_verbosity(transport, option_verbosity, option_progress);
978         transport->family = family;
979
980         path = get_repo_path(remote->url[0], &is_bundle);
981         is_local = option_local != 0 && path && !is_bundle;
982         if (is_local) {
983                 if (option_depth)
984                         warning(_("--depth is ignored in local clones; use file:// instead."));
985                 if (!access(mkpath("%s/shallow", path), F_OK)) {
986                         if (option_local > 0)
987                                 warning(_("source repository is shallow, ignoring --local"));
988                         is_local = 0;
989                 }
990         }
991         if (option_local > 0 && !is_local)
992                 warning(_("--local is ignored"));
993         transport->cloning = 1;
994
995         if (!transport->get_refs_list || (!is_local && !transport->fetch))
996                 die(_("Don't know how to clone %s"), transport->url);
997
998         transport_set_option(transport, TRANS_OPT_KEEP, "yes");
999
1000         if (option_depth)
1001                 transport_set_option(transport, TRANS_OPT_DEPTH,
1002                                      option_depth);
1003         if (option_single_branch)
1004                 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
1005
1006         if (option_upload_pack)
1007                 transport_set_option(transport, TRANS_OPT_UPLOADPACK,
1008                                      option_upload_pack);
1009
1010         if (transport->smart_options && !option_depth)
1011                 transport->smart_options->check_self_contained_and_connected = 1;
1012
1013         refs = transport_get_remote_refs(transport);
1014
1015         if (refs) {
1016                 mapped_refs = wanted_peer_refs(refs, refspec);
1017                 /*
1018                  * transport_get_remote_refs() may return refs with null sha-1
1019                  * in mapped_refs (see struct transport->get_refs_list
1020                  * comment). In that case we need fetch it early because
1021                  * remote_head code below relies on it.
1022                  *
1023                  * for normal clones, transport_get_remote_refs() should
1024                  * return reliable ref set, we can delay cloning until after
1025                  * remote HEAD check.
1026                  */
1027                 for (ref = refs; ref; ref = ref->next)
1028                         if (is_null_oid(&ref->old_oid)) {
1029                                 complete_refs_before_fetch = 0;
1030                                 break;
1031                         }
1032
1033                 if (!is_local && !complete_refs_before_fetch)
1034                         transport_fetch_refs(transport, mapped_refs);
1035
1036                 remote_head = find_ref_by_name(refs, "HEAD");
1037                 remote_head_points_at =
1038                         guess_remote_head(remote_head, mapped_refs, 0);
1039
1040                 if (option_branch) {
1041                         our_head_points_at =
1042                                 find_remote_branch(mapped_refs, option_branch);
1043
1044                         if (!our_head_points_at)
1045                                 die(_("Remote branch %s not found in upstream %s"),
1046                                     option_branch, option_origin);
1047                 }
1048                 else
1049                         our_head_points_at = remote_head_points_at;
1050         }
1051         else {
1052                 if (option_branch)
1053                         die(_("Remote branch %s not found in upstream %s"),
1054                                         option_branch, option_origin);
1055
1056                 warning(_("You appear to have cloned an empty repository."));
1057                 mapped_refs = NULL;
1058                 our_head_points_at = NULL;
1059                 remote_head_points_at = NULL;
1060                 remote_head = NULL;
1061                 option_no_checkout = 1;
1062                 if (!option_bare)
1063                         install_branch_config(0, "master", option_origin,
1064                                               "refs/heads/master");
1065         }
1066
1067         write_refspec_config(src_ref_prefix, our_head_points_at,
1068                         remote_head_points_at, &branch_top);
1069
1070         if (is_local)
1071                 clone_local(path, git_dir);
1072         else if (refs && complete_refs_before_fetch)
1073                 transport_fetch_refs(transport, mapped_refs);
1074
1075         update_remote_refs(refs, mapped_refs, remote_head_points_at,
1076                            branch_top.buf, reflog_msg.buf, transport, !is_local);
1077
1078         update_head(our_head_points_at, remote_head, reflog_msg.buf);
1079
1080         transport_unlock_pack(transport);
1081         transport_disconnect(transport);
1082
1083         if (option_dissociate) {
1084                 close_all_packs();
1085                 dissociate_from_references();
1086         }
1087
1088         junk_mode = JUNK_LEAVE_REPO;
1089         err = checkout();
1090
1091         strbuf_release(&reflog_msg);
1092         strbuf_release(&branch_top);
1093         strbuf_release(&key);
1094         strbuf_release(&value);
1095         junk_mode = JUNK_LEAVE_ALL;
1096
1097         free(refspec);
1098         return err;
1099 }