sha1collisiondetection: automatically enable when submodule is populated
[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;
43 static int option_shallow_submodules;
44 static int deepen;
45 static char *option_template, *option_depth, *option_since;
46 static char *option_origin = NULL;
47 static char *option_branch = NULL;
48 static struct string_list option_not = STRING_LIST_INIT_NODUP;
49 static const char *real_git_dir;
50 static char *option_upload_pack = "git-upload-pack";
51 static int option_verbosity;
52 static int option_progress = -1;
53 static enum transport_family family;
54 static struct string_list option_config = STRING_LIST_INIT_NODUP;
55 static struct string_list option_required_reference = STRING_LIST_INIT_NODUP;
56 static struct string_list option_optional_reference = STRING_LIST_INIT_NODUP;
57 static int option_dissociate;
58 static int max_jobs = -1;
59 static struct string_list option_recurse_submodules = STRING_LIST_INIT_NODUP;
60
61 static int recurse_submodules_cb(const struct option *opt,
62                                  const char *arg, int unset)
63 {
64         if (unset)
65                 string_list_clear((struct string_list *)opt->value, 0);
66         else if (arg)
67                 string_list_append((struct string_list *)opt->value, arg);
68         else
69                 string_list_append((struct string_list *)opt->value,
70                                    (const char *)opt->defval);
71
72         return 0;
73 }
74
75 static struct option builtin_clone_options[] = {
76         OPT__VERBOSITY(&option_verbosity),
77         OPT_BOOL(0, "progress", &option_progress,
78                  N_("force progress reporting")),
79         OPT_BOOL('n', "no-checkout", &option_no_checkout,
80                  N_("don't create a checkout")),
81         OPT_BOOL(0, "bare", &option_bare, N_("create a bare repository")),
82         OPT_HIDDEN_BOOL(0, "naked", &option_bare,
83                         N_("create a bare repository")),
84         OPT_BOOL(0, "mirror", &option_mirror,
85                  N_("create a mirror repository (implies bare)")),
86         OPT_BOOL('l', "local", &option_local,
87                 N_("to clone from a local repository")),
88         OPT_BOOL(0, "no-hardlinks", &option_no_hardlinks,
89                     N_("don't use local hardlinks, always copy")),
90         OPT_BOOL('s', "shared", &option_shared,
91                     N_("setup as shared repository")),
92         { OPTION_CALLBACK, 0, "recursive", &option_recurse_submodules,
93           N_("pathspec"), N_("initialize submodules in the clone"),
94           PARSE_OPT_OPTARG | PARSE_OPT_HIDDEN, recurse_submodules_cb,
95           (intptr_t)"." },
96         { OPTION_CALLBACK, 0, "recurse-submodules", &option_recurse_submodules,
97           N_("pathspec"), N_("initialize submodules in the clone"),
98           PARSE_OPT_OPTARG, recurse_submodules_cb, (intptr_t)"." },
99         OPT_INTEGER('j', "jobs", &max_jobs,
100                     N_("number of submodules cloned in parallel")),
101         OPT_STRING(0, "template", &option_template, N_("template-directory"),
102                    N_("directory from which templates will be used")),
103         OPT_STRING_LIST(0, "reference", &option_required_reference, N_("repo"),
104                         N_("reference repository")),
105         OPT_STRING_LIST(0, "reference-if-able", &option_optional_reference,
106                         N_("repo"), N_("reference repository")),
107         OPT_BOOL(0, "dissociate", &option_dissociate,
108                  N_("use --reference only while cloning")),
109         OPT_STRING('o', "origin", &option_origin, N_("name"),
110                    N_("use <name> instead of 'origin' to track upstream")),
111         OPT_STRING('b', "branch", &option_branch, N_("branch"),
112                    N_("checkout <branch> instead of the remote's HEAD")),
113         OPT_STRING('u', "upload-pack", &option_upload_pack, N_("path"),
114                    N_("path to git-upload-pack on the remote")),
115         OPT_STRING(0, "depth", &option_depth, N_("depth"),
116                     N_("create a shallow clone of that depth")),
117         OPT_STRING(0, "shallow-since", &option_since, N_("time"),
118                     N_("create a shallow clone since a specific time")),
119         OPT_STRING_LIST(0, "shallow-exclude", &option_not, N_("revision"),
120                         N_("deepen history of shallow clone, excluding rev")),
121         OPT_BOOL(0, "single-branch", &option_single_branch,
122                     N_("clone only one branch, HEAD or --branch")),
123         OPT_BOOL(0, "shallow-submodules", &option_shallow_submodules,
124                     N_("any cloned submodules will be shallow")),
125         OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
126                    N_("separate git dir from working tree")),
127         OPT_STRING_LIST('c', "config", &option_config, N_("key=value"),
128                         N_("set config inside the new repository")),
129         OPT_SET_INT('4', "ipv4", &family, N_("use IPv4 addresses only"),
130                         TRANSPORT_FAMILY_IPV4),
131         OPT_SET_INT('6', "ipv6", &family, N_("use IPv6 addresses only"),
132                         TRANSPORT_FAMILY_IPV6),
133         OPT_END()
134 };
135
136 static const char *get_repo_path_1(struct strbuf *path, int *is_bundle)
137 {
138         static char *suffix[] = { "/.git", "", ".git/.git", ".git" };
139         static char *bundle_suffix[] = { ".bundle", "" };
140         size_t baselen = path->len;
141         struct stat st;
142         int i;
143
144         for (i = 0; i < ARRAY_SIZE(suffix); i++) {
145                 strbuf_setlen(path, baselen);
146                 strbuf_addstr(path, suffix[i]);
147                 if (stat(path->buf, &st))
148                         continue;
149                 if (S_ISDIR(st.st_mode) && is_git_directory(path->buf)) {
150                         *is_bundle = 0;
151                         return path->buf;
152                 } else if (S_ISREG(st.st_mode) && st.st_size > 8) {
153                         /* Is it a "gitfile"? */
154                         char signature[8];
155                         const char *dst;
156                         int len, fd = open(path->buf, O_RDONLY);
157                         if (fd < 0)
158                                 continue;
159                         len = read_in_full(fd, signature, 8);
160                         close(fd);
161                         if (len != 8 || strncmp(signature, "gitdir: ", 8))
162                                 continue;
163                         dst = read_gitfile(path->buf);
164                         if (dst) {
165                                 *is_bundle = 0;
166                                 return dst;
167                         }
168                 }
169         }
170
171         for (i = 0; i < ARRAY_SIZE(bundle_suffix); i++) {
172                 strbuf_setlen(path, baselen);
173                 strbuf_addstr(path, bundle_suffix[i]);
174                 if (!stat(path->buf, &st) && S_ISREG(st.st_mode)) {
175                         *is_bundle = 1;
176                         return path->buf;
177                 }
178         }
179
180         return NULL;
181 }
182
183 static char *get_repo_path(const char *repo, int *is_bundle)
184 {
185         struct strbuf path = STRBUF_INIT;
186         const char *raw;
187         char *canon;
188
189         strbuf_addstr(&path, repo);
190         raw = get_repo_path_1(&path, is_bundle);
191         canon = raw ? absolute_pathdup(raw) : NULL;
192         strbuf_release(&path);
193         return canon;
194 }
195
196 static char *guess_dir_name(const char *repo, int is_bundle, int is_bare)
197 {
198         const char *end = repo + strlen(repo), *start, *ptr;
199         size_t len;
200         char *dir;
201
202         /*
203          * Skip scheme.
204          */
205         start = strstr(repo, "://");
206         if (start == NULL)
207                 start = repo;
208         else
209                 start += 3;
210
211         /*
212          * Skip authentication data. The stripping does happen
213          * greedily, such that we strip up to the last '@' inside
214          * the host part.
215          */
216         for (ptr = start; ptr < end && !is_dir_sep(*ptr); ptr++) {
217                 if (*ptr == '@')
218                         start = ptr + 1;
219         }
220
221         /*
222          * Strip trailing spaces, slashes and /.git
223          */
224         while (start < end && (is_dir_sep(end[-1]) || isspace(end[-1])))
225                 end--;
226         if (end - start > 5 && is_dir_sep(end[-5]) &&
227             !strncmp(end - 4, ".git", 4)) {
228                 end -= 5;
229                 while (start < end && is_dir_sep(end[-1]))
230                         end--;
231         }
232
233         /*
234          * Strip trailing port number if we've got only a
235          * hostname (that is, there is no dir separator but a
236          * colon). This check is required such that we do not
237          * strip URI's like '/foo/bar:2222.git', which should
238          * result in a dir '2222' being guessed due to backwards
239          * compatibility.
240          */
241         if (memchr(start, '/', end - start) == NULL
242             && memchr(start, ':', end - start) != NULL) {
243                 ptr = end;
244                 while (start < ptr && isdigit(ptr[-1]) && ptr[-1] != ':')
245                         ptr--;
246                 if (start < ptr && ptr[-1] == ':')
247                         end = ptr - 1;
248         }
249
250         /*
251          * Find last component. To remain backwards compatible we
252          * also regard colons as path separators, such that
253          * cloning a repository 'foo:bar.git' would result in a
254          * directory 'bar' being guessed.
255          */
256         ptr = end;
257         while (start < ptr && !is_dir_sep(ptr[-1]) && ptr[-1] != ':')
258                 ptr--;
259         start = ptr;
260
261         /*
262          * Strip .{bundle,git}.
263          */
264         len = end - start;
265         strip_suffix_mem(start, &len, is_bundle ? ".bundle" : ".git");
266
267         if (!len || (len == 1 && *start == '/'))
268                 die(_("No directory name could be guessed.\n"
269                       "Please specify a directory on the command line"));
270
271         if (is_bare)
272                 dir = xstrfmt("%.*s.git", (int)len, start);
273         else
274                 dir = xstrndup(start, len);
275         /*
276          * Replace sequences of 'control' characters and whitespace
277          * with one ascii space, remove leading and trailing spaces.
278          */
279         if (*dir) {
280                 char *out = dir;
281                 int prev_space = 1 /* strip leading whitespace */;
282                 for (end = dir; *end; ++end) {
283                         char ch = *end;
284                         if ((unsigned char)ch < '\x20')
285                                 ch = '\x20';
286                         if (isspace(ch)) {
287                                 if (prev_space)
288                                         continue;
289                                 prev_space = 1;
290                         } else
291                                 prev_space = 0;
292                         *out++ = ch;
293                 }
294                 *out = '\0';
295                 if (out > dir && prev_space)
296                         out[-1] = '\0';
297         }
298         return dir;
299 }
300
301 static void strip_trailing_slashes(char *dir)
302 {
303         char *end = dir + strlen(dir);
304
305         while (dir < end - 1 && is_dir_sep(end[-1]))
306                 end--;
307         *end = '\0';
308 }
309
310 static int add_one_reference(struct string_list_item *item, void *cb_data)
311 {
312         struct strbuf err = STRBUF_INIT;
313         int *required = cb_data;
314         char *ref_git = compute_alternate_path(item->string, &err);
315
316         if (!ref_git) {
317                 if (*required)
318                         die("%s", err.buf);
319                 else
320                         fprintf(stderr,
321                                 _("info: Could not add alternate for '%s': %s\n"),
322                                 item->string, err.buf);
323         } else {
324                 struct strbuf sb = STRBUF_INIT;
325                 strbuf_addf(&sb, "%s/objects", ref_git);
326                 add_to_alternates_file(sb.buf);
327                 strbuf_release(&sb);
328         }
329
330         strbuf_release(&err);
331         free(ref_git);
332         return 0;
333 }
334
335 static void setup_reference(void)
336 {
337         int required = 1;
338         for_each_string_list(&option_required_reference,
339                              add_one_reference, &required);
340         required = 0;
341         for_each_string_list(&option_optional_reference,
342                              add_one_reference, &required);
343 }
344
345 static void copy_alternates(struct strbuf *src, struct strbuf *dst,
346                             const char *src_repo)
347 {
348         /*
349          * Read from the source objects/info/alternates file
350          * and copy the entries to corresponding file in the
351          * destination repository with add_to_alternates_file().
352          * Both src and dst have "$path/objects/info/alternates".
353          *
354          * Instead of copying bit-for-bit from the original,
355          * we need to append to existing one so that the already
356          * created entry via "clone -s" is not lost, and also
357          * to turn entries with paths relative to the original
358          * absolute, so that they can be used in the new repository.
359          */
360         FILE *in = fopen(src->buf, "r");
361         struct strbuf line = STRBUF_INIT;
362
363         while (strbuf_getline(&line, in) != EOF) {
364                 char *abs_path;
365                 if (!line.len || line.buf[0] == '#')
366                         continue;
367                 if (is_absolute_path(line.buf)) {
368                         add_to_alternates_file(line.buf);
369                         continue;
370                 }
371                 abs_path = mkpathdup("%s/objects/%s", src_repo, line.buf);
372                 if (!normalize_path_copy(abs_path, abs_path))
373                         add_to_alternates_file(abs_path);
374                 else
375                         warning("skipping invalid relative alternate: %s/%s",
376                                 src_repo, line.buf);
377                 free(abs_path);
378         }
379         strbuf_release(&line);
380         fclose(in);
381 }
382
383 static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
384                                    const char *src_repo, int src_baselen)
385 {
386         struct dirent *de;
387         struct stat buf;
388         int src_len, dest_len;
389         DIR *dir;
390
391         dir = opendir(src->buf);
392         if (!dir)
393                 die_errno(_("failed to open '%s'"), src->buf);
394
395         if (mkdir(dest->buf, 0777)) {
396                 if (errno != EEXIST)
397                         die_errno(_("failed to create directory '%s'"), dest->buf);
398                 else if (stat(dest->buf, &buf))
399                         die_errno(_("failed to stat '%s'"), dest->buf);
400                 else if (!S_ISDIR(buf.st_mode))
401                         die(_("%s exists and is not a directory"), dest->buf);
402         }
403
404         strbuf_addch(src, '/');
405         src_len = src->len;
406         strbuf_addch(dest, '/');
407         dest_len = dest->len;
408
409         while ((de = readdir(dir)) != NULL) {
410                 strbuf_setlen(src, src_len);
411                 strbuf_addstr(src, de->d_name);
412                 strbuf_setlen(dest, dest_len);
413                 strbuf_addstr(dest, de->d_name);
414                 if (stat(src->buf, &buf)) {
415                         warning (_("failed to stat %s\n"), src->buf);
416                         continue;
417                 }
418                 if (S_ISDIR(buf.st_mode)) {
419                         if (de->d_name[0] != '.')
420                                 copy_or_link_directory(src, dest,
421                                                        src_repo, src_baselen);
422                         continue;
423                 }
424
425                 /* Files that cannot be copied bit-for-bit... */
426                 if (!strcmp(src->buf + src_baselen, "/info/alternates")) {
427                         copy_alternates(src, dest, src_repo);
428                         continue;
429                 }
430
431                 if (unlink(dest->buf) && errno != ENOENT)
432                         die_errno(_("failed to unlink '%s'"), dest->buf);
433                 if (!option_no_hardlinks) {
434                         if (!link(src->buf, dest->buf))
435                                 continue;
436                         if (option_local > 0)
437                                 die_errno(_("failed to create link '%s'"), dest->buf);
438                         option_no_hardlinks = 1;
439                 }
440                 if (copy_file_with_time(dest->buf, src->buf, 0666))
441                         die_errno(_("failed to copy file to '%s'"), dest->buf);
442         }
443         closedir(dir);
444 }
445
446 static void clone_local(const char *src_repo, const char *dest_repo)
447 {
448         if (option_shared) {
449                 struct strbuf alt = STRBUF_INIT;
450                 strbuf_addf(&alt, "%s/objects", src_repo);
451                 add_to_alternates_file(alt.buf);
452                 strbuf_release(&alt);
453         } else {
454                 struct strbuf src = STRBUF_INIT;
455                 struct strbuf dest = STRBUF_INIT;
456                 get_common_dir(&src, src_repo);
457                 get_common_dir(&dest, dest_repo);
458                 strbuf_addstr(&src, "/objects");
459                 strbuf_addstr(&dest, "/objects");
460                 copy_or_link_directory(&src, &dest, src_repo, src.len);
461                 strbuf_release(&src);
462                 strbuf_release(&dest);
463         }
464
465         if (0 <= option_verbosity)
466                 fprintf(stderr, _("done.\n"));
467 }
468
469 static const char *junk_work_tree;
470 static const char *junk_git_dir;
471 static enum {
472         JUNK_LEAVE_NONE,
473         JUNK_LEAVE_REPO,
474         JUNK_LEAVE_ALL
475 } junk_mode = JUNK_LEAVE_NONE;
476
477 static const char junk_leave_repo_msg[] =
478 N_("Clone succeeded, but checkout failed.\n"
479    "You can inspect what was checked out with 'git status'\n"
480    "and retry the checkout with 'git checkout -f HEAD'\n");
481
482 static void remove_junk(void)
483 {
484         struct strbuf sb = STRBUF_INIT;
485
486         switch (junk_mode) {
487         case JUNK_LEAVE_REPO:
488                 warning("%s", _(junk_leave_repo_msg));
489                 /* fall-through */
490         case JUNK_LEAVE_ALL:
491                 return;
492         default:
493                 /* proceed to removal */
494                 break;
495         }
496
497         if (junk_git_dir) {
498                 strbuf_addstr(&sb, junk_git_dir);
499                 remove_dir_recursively(&sb, 0);
500                 strbuf_reset(&sb);
501         }
502         if (junk_work_tree) {
503                 strbuf_addstr(&sb, junk_work_tree);
504                 remove_dir_recursively(&sb, 0);
505                 strbuf_reset(&sb);
506         }
507 }
508
509 static void remove_junk_on_signal(int signo)
510 {
511         remove_junk();
512         sigchain_pop(signo);
513         raise(signo);
514 }
515
516 static struct ref *find_remote_branch(const struct ref *refs, const char *branch)
517 {
518         struct ref *ref;
519         struct strbuf head = STRBUF_INIT;
520         strbuf_addstr(&head, "refs/heads/");
521         strbuf_addstr(&head, branch);
522         ref = find_ref_by_name(refs, head.buf);
523         strbuf_release(&head);
524
525         if (ref)
526                 return ref;
527
528         strbuf_addstr(&head, "refs/tags/");
529         strbuf_addstr(&head, branch);
530         ref = find_ref_by_name(refs, head.buf);
531         strbuf_release(&head);
532
533         return ref;
534 }
535
536 static struct ref *wanted_peer_refs(const struct ref *refs,
537                 struct refspec *refspec)
538 {
539         struct ref *head = copy_ref(find_ref_by_name(refs, "HEAD"));
540         struct ref *local_refs = head;
541         struct ref **tail = head ? &head->next : &local_refs;
542
543         if (option_single_branch) {
544                 struct ref *remote_head = NULL;
545
546                 if (!option_branch)
547                         remote_head = guess_remote_head(head, refs, 0);
548                 else {
549                         local_refs = NULL;
550                         tail = &local_refs;
551                         remote_head = copy_ref(find_remote_branch(refs, option_branch));
552                 }
553
554                 if (!remote_head && option_branch)
555                         warning(_("Could not find remote branch %s to clone."),
556                                 option_branch);
557                 else {
558                         get_fetch_map(remote_head, refspec, &tail, 0);
559
560                         /* if --branch=tag, pull the requested tag explicitly */
561                         get_fetch_map(remote_head, tag_refspec, &tail, 0);
562                 }
563         } else
564                 get_fetch_map(refs, refspec, &tail, 0);
565
566         if (!option_mirror && !option_single_branch)
567                 get_fetch_map(refs, tag_refspec, &tail, 0);
568
569         return local_refs;
570 }
571
572 static void write_remote_refs(const struct ref *local_refs)
573 {
574         const struct ref *r;
575
576         struct ref_transaction *t;
577         struct strbuf err = STRBUF_INIT;
578
579         t = ref_transaction_begin(&err);
580         if (!t)
581                 die("%s", err.buf);
582
583         for (r = local_refs; r; r = r->next) {
584                 if (!r->peer_ref)
585                         continue;
586                 if (ref_transaction_create(t, r->peer_ref->name, r->old_oid.hash,
587                                            0, NULL, &err))
588                         die("%s", err.buf);
589         }
590
591         if (initial_ref_transaction_commit(t, &err))
592                 die("%s", err.buf);
593
594         strbuf_release(&err);
595         ref_transaction_free(t);
596 }
597
598 static void write_followtags(const struct ref *refs, const char *msg)
599 {
600         const struct ref *ref;
601         for (ref = refs; ref; ref = ref->next) {
602                 if (!starts_with(ref->name, "refs/tags/"))
603                         continue;
604                 if (ends_with(ref->name, "^{}"))
605                         continue;
606                 if (!has_object_file(&ref->old_oid))
607                         continue;
608                 update_ref(msg, ref->name, ref->old_oid.hash,
609                            NULL, 0, UPDATE_REFS_DIE_ON_ERR);
610         }
611 }
612
613 static int iterate_ref_map(void *cb_data, unsigned char sha1[20])
614 {
615         struct ref **rm = cb_data;
616         struct ref *ref = *rm;
617
618         /*
619          * Skip anything missing a peer_ref, which we are not
620          * actually going to write a ref for.
621          */
622         while (ref && !ref->peer_ref)
623                 ref = ref->next;
624         /* Returning -1 notes "end of list" to the caller. */
625         if (!ref)
626                 return -1;
627
628         hashcpy(sha1, ref->old_oid.hash);
629         *rm = ref->next;
630         return 0;
631 }
632
633 static void update_remote_refs(const struct ref *refs,
634                                const struct ref *mapped_refs,
635                                const struct ref *remote_head_points_at,
636                                const char *branch_top,
637                                const char *msg,
638                                struct transport *transport,
639                                int check_connectivity)
640 {
641         const struct ref *rm = mapped_refs;
642
643         if (check_connectivity) {
644                 struct check_connected_options opt = CHECK_CONNECTED_INIT;
645
646                 opt.transport = transport;
647                 opt.progress = transport->progress;
648
649                 if (check_connected(iterate_ref_map, &rm, &opt))
650                         die(_("remote did not send all necessary objects"));
651         }
652
653         if (refs) {
654                 write_remote_refs(mapped_refs);
655                 if (option_single_branch)
656                         write_followtags(refs, msg);
657         }
658
659         if (remote_head_points_at && !option_bare) {
660                 struct strbuf head_ref = STRBUF_INIT;
661                 strbuf_addstr(&head_ref, branch_top);
662                 strbuf_addstr(&head_ref, "HEAD");
663                 if (create_symref(head_ref.buf,
664                                   remote_head_points_at->peer_ref->name,
665                                   msg) < 0)
666                         die(_("unable to update %s"), head_ref.buf);
667                 strbuf_release(&head_ref);
668         }
669 }
670
671 static void update_head(const struct ref *our, const struct ref *remote,
672                         const char *msg)
673 {
674         const char *head;
675         if (our && skip_prefix(our->name, "refs/heads/", &head)) {
676                 /* Local default branch link */
677                 if (create_symref("HEAD", our->name, NULL) < 0)
678                         die(_("unable to update HEAD"));
679                 if (!option_bare) {
680                         update_ref(msg, "HEAD", our->old_oid.hash, NULL, 0,
681                                    UPDATE_REFS_DIE_ON_ERR);
682                         install_branch_config(0, head, option_origin, our->name);
683                 }
684         } else if (our) {
685                 struct commit *c = lookup_commit_reference(our->old_oid.hash);
686                 /* --branch specifies a non-branch (i.e. tags), detach HEAD */
687                 update_ref(msg, "HEAD", c->object.oid.hash,
688                            NULL, REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
689         } else if (remote) {
690                 /*
691                  * We know remote HEAD points to a non-branch, or
692                  * HEAD points to a branch but we don't know which one.
693                  * Detach HEAD in all these cases.
694                  */
695                 update_ref(msg, "HEAD", remote->old_oid.hash,
696                            NULL, REF_NODEREF, UPDATE_REFS_DIE_ON_ERR);
697         }
698 }
699
700 static int checkout(int submodule_progress)
701 {
702         struct object_id oid;
703         char *head;
704         struct lock_file *lock_file;
705         struct unpack_trees_options opts;
706         struct tree *tree;
707         struct tree_desc t;
708         int err = 0;
709
710         if (option_no_checkout)
711                 return 0;
712
713         head = resolve_refdup("HEAD", RESOLVE_REF_READING, oid.hash, NULL);
714         if (!head) {
715                 warning(_("remote HEAD refers to nonexistent ref, "
716                           "unable to checkout.\n"));
717                 return 0;
718         }
719         if (!strcmp(head, "HEAD")) {
720                 if (advice_detached_head)
721                         detach_advice(oid_to_hex(&oid));
722         } else {
723                 if (!starts_with(head, "refs/heads/"))
724                         die(_("HEAD not found below refs/heads!"));
725         }
726         free(head);
727
728         /* We need to be in the new work tree for the checkout */
729         setup_work_tree();
730
731         lock_file = xcalloc(1, sizeof(struct lock_file));
732         hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
733
734         memset(&opts, 0, sizeof opts);
735         opts.update = 1;
736         opts.merge = 1;
737         opts.fn = oneway_merge;
738         opts.verbose_update = (option_verbosity >= 0);
739         opts.src_index = &the_index;
740         opts.dst_index = &the_index;
741
742         tree = parse_tree_indirect(oid.hash);
743         parse_tree(tree);
744         init_tree_desc(&t, tree->buffer, tree->size);
745         if (unpack_trees(1, &t, &opts) < 0)
746                 die(_("unable to checkout working tree"));
747
748         if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
749                 die(_("unable to write new index file"));
750
751         err |= run_hook_le(NULL, "post-checkout", sha1_to_hex(null_sha1),
752                            oid_to_hex(&oid), "1", NULL);
753
754         if (!err && (option_recurse_submodules.nr > 0)) {
755                 struct argv_array args = ARGV_ARRAY_INIT;
756                 argv_array_pushl(&args, "submodule", "update", "--init", "--recursive", NULL);
757
758                 if (option_shallow_submodules == 1)
759                         argv_array_push(&args, "--depth=1");
760
761                 if (max_jobs != -1)
762                         argv_array_pushf(&args, "--jobs=%d", max_jobs);
763
764                 if (submodule_progress)
765                         argv_array_push(&args, "--progress");
766
767                 err = run_command_v_opt(args.argv, RUN_GIT_CMD);
768                 argv_array_clear(&args);
769         }
770
771         return err;
772 }
773
774 static int write_one_config(const char *key, const char *value, void *data)
775 {
776         return git_config_set_multivar_gently(key, value ? value : "true", "^$", 0);
777 }
778
779 static void write_config(struct string_list *config)
780 {
781         int i;
782
783         for (i = 0; i < config->nr; i++) {
784                 if (git_config_parse_parameter(config->items[i].string,
785                                                write_one_config, NULL) < 0)
786                         die(_("unable to write parameters to config file"));
787         }
788 }
789
790 static void write_refspec_config(const char *src_ref_prefix,
791                 const struct ref *our_head_points_at,
792                 const struct ref *remote_head_points_at,
793                 struct strbuf *branch_top)
794 {
795         struct strbuf key = STRBUF_INIT;
796         struct strbuf value = STRBUF_INIT;
797
798         if (option_mirror || !option_bare) {
799                 if (option_single_branch && !option_mirror) {
800                         if (option_branch) {
801                                 if (starts_with(our_head_points_at->name, "refs/tags/"))
802                                         strbuf_addf(&value, "+%s:%s", our_head_points_at->name,
803                                                 our_head_points_at->name);
804                                 else
805                                         strbuf_addf(&value, "+%s:%s%s", our_head_points_at->name,
806                                                 branch_top->buf, option_branch);
807                         } else if (remote_head_points_at) {
808                                 const char *head = remote_head_points_at->name;
809                                 if (!skip_prefix(head, "refs/heads/", &head))
810                                         die("BUG: remote HEAD points at non-head?");
811
812                                 strbuf_addf(&value, "+%s:%s%s", remote_head_points_at->name,
813                                                 branch_top->buf, head);
814                         }
815                         /*
816                          * otherwise, the next "git fetch" will
817                          * simply fetch from HEAD without updating
818                          * any remote-tracking branch, which is what
819                          * we want.
820                          */
821                 } else {
822                         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top->buf);
823                 }
824                 /* Configure the remote */
825                 if (value.len) {
826                         strbuf_addf(&key, "remote.%s.fetch", option_origin);
827                         git_config_set_multivar(key.buf, value.buf, "^$", 0);
828                         strbuf_reset(&key);
829
830                         if (option_mirror) {
831                                 strbuf_addf(&key, "remote.%s.mirror", option_origin);
832                                 git_config_set(key.buf, "true");
833                                 strbuf_reset(&key);
834                         }
835                 }
836         }
837
838         strbuf_release(&key);
839         strbuf_release(&value);
840 }
841
842 static void dissociate_from_references(void)
843 {
844         static const char* argv[] = { "repack", "-a", "-d", NULL };
845         char *alternates = git_pathdup("objects/info/alternates");
846
847         if (!access(alternates, F_OK)) {
848                 if (run_command_v_opt(argv, RUN_GIT_CMD|RUN_COMMAND_NO_STDIN))
849                         die(_("cannot repack to clean up"));
850                 if (unlink(alternates) && errno != ENOENT)
851                         die_errno(_("cannot unlink temporary alternates file"));
852         }
853         free(alternates);
854 }
855
856 int cmd_clone(int argc, const char **argv, const char *prefix)
857 {
858         int is_bundle = 0, is_local;
859         struct stat buf;
860         const char *repo_name, *repo, *work_tree, *git_dir;
861         char *path, *dir;
862         int dest_exists;
863         const struct ref *refs, *remote_head;
864         const struct ref *remote_head_points_at;
865         const struct ref *our_head_points_at;
866         struct ref *mapped_refs;
867         const struct ref *ref;
868         struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
869         struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
870         struct transport *transport = NULL;
871         const char *src_ref_prefix = "refs/heads/";
872         struct remote *remote;
873         int err = 0, complete_refs_before_fetch = 1;
874         int submodule_progress;
875
876         struct refspec *refspec;
877         const char *fetch_pattern;
878
879         packet_trace_identity("clone");
880         argc = parse_options(argc, argv, prefix, builtin_clone_options,
881                              builtin_clone_usage, 0);
882
883         if (argc > 2)
884                 usage_msg_opt(_("Too many arguments."),
885                         builtin_clone_usage, builtin_clone_options);
886
887         if (argc == 0)
888                 usage_msg_opt(_("You must specify a repository to clone."),
889                         builtin_clone_usage, builtin_clone_options);
890
891         if (option_depth || option_since || option_not.nr)
892                 deepen = 1;
893         if (option_single_branch == -1)
894                 option_single_branch = deepen ? 1 : 0;
895
896         if (option_mirror)
897                 option_bare = 1;
898
899         if (option_bare) {
900                 if (option_origin)
901                         die(_("--bare and --origin %s options are incompatible."),
902                             option_origin);
903                 if (real_git_dir)
904                         die(_("--bare and --separate-git-dir are incompatible."));
905                 option_no_checkout = 1;
906         }
907
908         if (!option_origin)
909                 option_origin = "origin";
910
911         repo_name = argv[0];
912
913         path = get_repo_path(repo_name, &is_bundle);
914         if (path)
915                 repo = absolute_pathdup(repo_name);
916         else if (!strchr(repo_name, ':'))
917                 die(_("repository '%s' does not exist"), repo_name);
918         else
919                 repo = repo_name;
920
921         /* no need to be strict, transport_set_option() will validate it again */
922         if (option_depth && atoi(option_depth) < 1)
923                 die(_("depth %s is not a positive number"), option_depth);
924
925         if (argc == 2)
926                 dir = xstrdup(argv[1]);
927         else
928                 dir = guess_dir_name(repo_name, is_bundle, option_bare);
929         strip_trailing_slashes(dir);
930
931         dest_exists = !stat(dir, &buf);
932         if (dest_exists && !is_empty_dir(dir))
933                 die(_("destination path '%s' already exists and is not "
934                         "an empty directory."), dir);
935
936         strbuf_addf(&reflog_msg, "clone: from %s", repo);
937
938         if (option_bare)
939                 work_tree = NULL;
940         else {
941                 work_tree = getenv("GIT_WORK_TREE");
942                 if (work_tree && !stat(work_tree, &buf))
943                         die(_("working tree '%s' already exists."), work_tree);
944         }
945
946         if (option_bare || work_tree)
947                 git_dir = xstrdup(dir);
948         else {
949                 work_tree = dir;
950                 git_dir = mkpathdup("%s/.git", dir);
951         }
952
953         atexit(remove_junk);
954         sigchain_push_common(remove_junk_on_signal);
955
956         if (!option_bare) {
957                 if (safe_create_leading_directories_const(work_tree) < 0)
958                         die_errno(_("could not create leading directories of '%s'"),
959                                   work_tree);
960                 if (!dest_exists && mkdir(work_tree, 0777))
961                         die_errno(_("could not create work tree dir '%s'"),
962                                   work_tree);
963                 junk_work_tree = work_tree;
964                 set_git_work_tree(work_tree);
965         }
966
967         junk_git_dir = real_git_dir ? real_git_dir : git_dir;
968         if (safe_create_leading_directories_const(git_dir) < 0)
969                 die(_("could not create leading directories of '%s'"), git_dir);
970
971         if (0 <= option_verbosity) {
972                 if (option_bare)
973                         fprintf(stderr, _("Cloning into bare repository '%s'...\n"), dir);
974                 else
975                         fprintf(stderr, _("Cloning into '%s'...\n"), dir);
976         }
977
978         if (option_recurse_submodules.nr > 0) {
979                 struct string_list_item *item;
980                 struct strbuf sb = STRBUF_INIT;
981
982                 /* remove duplicates */
983                 string_list_sort(&option_recurse_submodules);
984                 string_list_remove_duplicates(&option_recurse_submodules, 0);
985
986                 /*
987                  * NEEDSWORK: In a multi-working-tree world, this needs to be
988                  * set in the per-worktree config.
989                  */
990                 for_each_string_list_item(item, &option_recurse_submodules) {
991                         strbuf_addf(&sb, "submodule.active=%s",
992                                     item->string);
993                         string_list_append(&option_config,
994                                            strbuf_detach(&sb, NULL));
995                 }
996
997                 if (option_required_reference.nr &&
998                     option_optional_reference.nr)
999                         die(_("clone --recursive is not compatible with "
1000                               "both --reference and --reference-if-able"));
1001                 else if (option_required_reference.nr) {
1002                         string_list_append(&option_config,
1003                                 "submodule.alternateLocation=superproject");
1004                         string_list_append(&option_config,
1005                                 "submodule.alternateErrorStrategy=die");
1006                 } else if (option_optional_reference.nr) {
1007                         string_list_append(&option_config,
1008                                 "submodule.alternateLocation=superproject");
1009                         string_list_append(&option_config,
1010                                 "submodule.alternateErrorStrategy=info");
1011                 }
1012         }
1013
1014         init_db(git_dir, real_git_dir, option_template, INIT_DB_QUIET);
1015
1016         if (real_git_dir)
1017                 git_dir = real_git_dir;
1018
1019         write_config(&option_config);
1020
1021         git_config(git_default_config, NULL);
1022
1023         if (option_bare) {
1024                 if (option_mirror)
1025                         src_ref_prefix = "refs/";
1026                 strbuf_addstr(&branch_top, src_ref_prefix);
1027
1028                 git_config_set("core.bare", "true");
1029         } else {
1030                 strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
1031         }
1032
1033         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
1034         strbuf_addf(&key, "remote.%s.url", option_origin);
1035         git_config_set(key.buf, repo);
1036         strbuf_reset(&key);
1037
1038         if (option_required_reference.nr || option_optional_reference.nr)
1039                 setup_reference();
1040
1041         fetch_pattern = value.buf;
1042         refspec = parse_fetch_refspec(1, &fetch_pattern);
1043
1044         strbuf_reset(&value);
1045
1046         remote = remote_get(option_origin);
1047         transport = transport_get(remote, remote->url[0]);
1048         transport_set_verbosity(transport, option_verbosity, option_progress);
1049         transport->family = family;
1050
1051         path = get_repo_path(remote->url[0], &is_bundle);
1052         is_local = option_local != 0 && path && !is_bundle;
1053         if (is_local) {
1054                 if (option_depth)
1055                         warning(_("--depth is ignored in local clones; use file:// instead."));
1056                 if (option_since)
1057                         warning(_("--shallow-since is ignored in local clones; use file:// instead."));
1058                 if (option_not.nr)
1059                         warning(_("--shallow-exclude is ignored in local clones; use file:// instead."));
1060                 if (!access(mkpath("%s/shallow", path), F_OK)) {
1061                         if (option_local > 0)
1062                                 warning(_("source repository is shallow, ignoring --local"));
1063                         is_local = 0;
1064                 }
1065         }
1066         if (option_local > 0 && !is_local)
1067                 warning(_("--local is ignored"));
1068         transport->cloning = 1;
1069
1070         if (!transport->get_refs_list || (!is_local && !transport->fetch))
1071                 die(_("Don't know how to clone %s"), transport->url);
1072
1073         transport_set_option(transport, TRANS_OPT_KEEP, "yes");
1074
1075         if (option_depth)
1076                 transport_set_option(transport, TRANS_OPT_DEPTH,
1077                                      option_depth);
1078         if (option_since)
1079                 transport_set_option(transport, TRANS_OPT_DEEPEN_SINCE,
1080                                      option_since);
1081         if (option_not.nr)
1082                 transport_set_option(transport, TRANS_OPT_DEEPEN_NOT,
1083                                      (const char *)&option_not);
1084         if (option_single_branch)
1085                 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
1086
1087         if (option_upload_pack)
1088                 transport_set_option(transport, TRANS_OPT_UPLOADPACK,
1089                                      option_upload_pack);
1090
1091         if (transport->smart_options && !deepen)
1092                 transport->smart_options->check_self_contained_and_connected = 1;
1093
1094         refs = transport_get_remote_refs(transport);
1095
1096         if (refs) {
1097                 mapped_refs = wanted_peer_refs(refs, refspec);
1098                 /*
1099                  * transport_get_remote_refs() may return refs with null sha-1
1100                  * in mapped_refs (see struct transport->get_refs_list
1101                  * comment). In that case we need fetch it early because
1102                  * remote_head code below relies on it.
1103                  *
1104                  * for normal clones, transport_get_remote_refs() should
1105                  * return reliable ref set, we can delay cloning until after
1106                  * remote HEAD check.
1107                  */
1108                 for (ref = refs; ref; ref = ref->next)
1109                         if (is_null_oid(&ref->old_oid)) {
1110                                 complete_refs_before_fetch = 0;
1111                                 break;
1112                         }
1113
1114                 if (!is_local && !complete_refs_before_fetch)
1115                         transport_fetch_refs(transport, mapped_refs);
1116
1117                 remote_head = find_ref_by_name(refs, "HEAD");
1118                 remote_head_points_at =
1119                         guess_remote_head(remote_head, mapped_refs, 0);
1120
1121                 if (option_branch) {
1122                         our_head_points_at =
1123                                 find_remote_branch(mapped_refs, option_branch);
1124
1125                         if (!our_head_points_at)
1126                                 die(_("Remote branch %s not found in upstream %s"),
1127                                     option_branch, option_origin);
1128                 }
1129                 else
1130                         our_head_points_at = remote_head_points_at;
1131         }
1132         else {
1133                 if (option_branch)
1134                         die(_("Remote branch %s not found in upstream %s"),
1135                                         option_branch, option_origin);
1136
1137                 warning(_("You appear to have cloned an empty repository."));
1138                 mapped_refs = NULL;
1139                 our_head_points_at = NULL;
1140                 remote_head_points_at = NULL;
1141                 remote_head = NULL;
1142                 option_no_checkout = 1;
1143                 if (!option_bare)
1144                         install_branch_config(0, "master", option_origin,
1145                                               "refs/heads/master");
1146         }
1147
1148         write_refspec_config(src_ref_prefix, our_head_points_at,
1149                         remote_head_points_at, &branch_top);
1150
1151         if (is_local)
1152                 clone_local(path, git_dir);
1153         else if (refs && complete_refs_before_fetch)
1154                 transport_fetch_refs(transport, mapped_refs);
1155
1156         update_remote_refs(refs, mapped_refs, remote_head_points_at,
1157                            branch_top.buf, reflog_msg.buf, transport, !is_local);
1158
1159         update_head(our_head_points_at, remote_head, reflog_msg.buf);
1160
1161         /*
1162          * We want to show progress for recursive submodule clones iff
1163          * we did so for the main clone. But only the transport knows
1164          * the final decision for this flag, so we need to rescue the value
1165          * before we free the transport.
1166          */
1167         submodule_progress = transport->progress;
1168
1169         transport_unlock_pack(transport);
1170         transport_disconnect(transport);
1171
1172         if (option_dissociate) {
1173                 close_all_packs();
1174                 dissociate_from_references();
1175         }
1176
1177         junk_mode = JUNK_LEAVE_REPO;
1178         err = checkout(submodule_progress);
1179
1180         strbuf_release(&reflog_msg);
1181         strbuf_release(&branch_top);
1182         strbuf_release(&key);
1183         strbuf_release(&value);
1184         junk_mode = JUNK_LEAVE_ALL;
1185
1186         free(refspec);
1187         return err;
1188 }