refs: update ref transactions to use struct object_id
[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 "config.h"
13 #include "lockfile.h"
14 #include "parse-options.h"
15 #include "fetch-pack.h"
16 #include "refs.h"
17 #include "tree.h"
18 #include "tree-walk.h"
19 #include "unpack-trees.h"
20 #include "transport.h"
21 #include "strbuf.h"
22 #include "dir.h"
23 #include "sigchain.h"
24 #include "branch.h"
25 #include "remote.h"
26 #include "run-command.h"
27 #include "connected.h"
28 #include "packfile.h"
29
30 /*
31  * Overall FIXMEs:
32  *  - respect DB_ENVIRONMENT for .git/objects.
33  *
34  * Implementation notes:
35  *  - dropping use-separate-remote and no-separate-remote compatibility
36  *
37  */
38 static const char * const builtin_clone_usage[] = {
39         N_("git clone [<options>] [--] <repo> [<dir>]"),
40         NULL
41 };
42
43 static int option_no_checkout, option_bare, option_mirror, option_single_branch = -1;
44 static int option_local = -1, option_no_hardlinks, option_shared;
45 static int option_no_tags;
46 static int option_shallow_submodules;
47 static int deepen;
48 static char *option_template, *option_depth, *option_since;
49 static char *option_origin = NULL;
50 static char *option_branch = NULL;
51 static struct string_list option_not = STRING_LIST_INIT_NODUP;
52 static const char *real_git_dir;
53 static char *option_upload_pack = "git-upload-pack";
54 static int option_verbosity;
55 static int option_progress = -1;
56 static enum transport_family family;
57 static struct string_list option_config = STRING_LIST_INIT_NODUP;
58 static struct string_list option_required_reference = STRING_LIST_INIT_NODUP;
59 static struct string_list option_optional_reference = STRING_LIST_INIT_NODUP;
60 static int option_dissociate;
61 static int max_jobs = -1;
62 static struct string_list option_recurse_submodules = STRING_LIST_INIT_NODUP;
63
64 static int recurse_submodules_cb(const struct option *opt,
65                                  const char *arg, int unset)
66 {
67         if (unset)
68                 string_list_clear((struct string_list *)opt->value, 0);
69         else if (arg)
70                 string_list_append((struct string_list *)opt->value, arg);
71         else
72                 string_list_append((struct string_list *)opt->value,
73                                    (const char *)opt->defval);
74
75         return 0;
76 }
77
78 static struct option builtin_clone_options[] = {
79         OPT__VERBOSITY(&option_verbosity),
80         OPT_BOOL(0, "progress", &option_progress,
81                  N_("force progress reporting")),
82         OPT_BOOL('n', "no-checkout", &option_no_checkout,
83                  N_("don't create a checkout")),
84         OPT_BOOL(0, "bare", &option_bare, N_("create a bare repository")),
85         OPT_HIDDEN_BOOL(0, "naked", &option_bare,
86                         N_("create a bare repository")),
87         OPT_BOOL(0, "mirror", &option_mirror,
88                  N_("create a mirror repository (implies bare)")),
89         OPT_BOOL('l', "local", &option_local,
90                 N_("to clone from a local repository")),
91         OPT_BOOL(0, "no-hardlinks", &option_no_hardlinks,
92                     N_("don't use local hardlinks, always copy")),
93         OPT_BOOL('s', "shared", &option_shared,
94                     N_("setup as shared repository")),
95         { OPTION_CALLBACK, 0, "recursive", &option_recurse_submodules,
96           N_("pathspec"), N_("initialize submodules in the clone"),
97           PARSE_OPT_OPTARG | PARSE_OPT_HIDDEN, recurse_submodules_cb,
98           (intptr_t)"." },
99         { OPTION_CALLBACK, 0, "recurse-submodules", &option_recurse_submodules,
100           N_("pathspec"), N_("initialize submodules in the clone"),
101           PARSE_OPT_OPTARG, recurse_submodules_cb, (intptr_t)"." },
102         OPT_INTEGER('j', "jobs", &max_jobs,
103                     N_("number of submodules cloned in parallel")),
104         OPT_STRING(0, "template", &option_template, N_("template-directory"),
105                    N_("directory from which templates will be used")),
106         OPT_STRING_LIST(0, "reference", &option_required_reference, N_("repo"),
107                         N_("reference repository")),
108         OPT_STRING_LIST(0, "reference-if-able", &option_optional_reference,
109                         N_("repo"), N_("reference repository")),
110         OPT_BOOL(0, "dissociate", &option_dissociate,
111                  N_("use --reference only while cloning")),
112         OPT_STRING('o', "origin", &option_origin, N_("name"),
113                    N_("use <name> instead of 'origin' to track upstream")),
114         OPT_STRING('b', "branch", &option_branch, N_("branch"),
115                    N_("checkout <branch> instead of the remote's HEAD")),
116         OPT_STRING('u', "upload-pack", &option_upload_pack, N_("path"),
117                    N_("path to git-upload-pack on the remote")),
118         OPT_STRING(0, "depth", &option_depth, N_("depth"),
119                     N_("create a shallow clone of that depth")),
120         OPT_STRING(0, "shallow-since", &option_since, N_("time"),
121                     N_("create a shallow clone since a specific time")),
122         OPT_STRING_LIST(0, "shallow-exclude", &option_not, N_("revision"),
123                         N_("deepen history of shallow clone, excluding rev")),
124         OPT_BOOL(0, "single-branch", &option_single_branch,
125                     N_("clone only one branch, HEAD or --branch")),
126         OPT_BOOL(0, "no-tags", &option_no_tags,
127                  N_("don't clone any tags, and make later fetches not to follow them")),
128         OPT_BOOL(0, "shallow-submodules", &option_shallow_submodules,
129                     N_("any cloned submodules will be shallow")),
130         OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
131                    N_("separate git dir from working tree")),
132         OPT_STRING_LIST('c', "config", &option_config, N_("key=value"),
133                         N_("set config inside the new repository")),
134         OPT_SET_INT('4', "ipv4", &family, N_("use IPv4 addresses only"),
135                         TRANSPORT_FAMILY_IPV4),
136         OPT_SET_INT('6', "ipv6", &family, N_("use IPv6 addresses only"),
137                         TRANSPORT_FAMILY_IPV6),
138         OPT_END()
139 };
140
141 static const char *get_repo_path_1(struct strbuf *path, int *is_bundle)
142 {
143         static char *suffix[] = { "/.git", "", ".git/.git", ".git" };
144         static char *bundle_suffix[] = { ".bundle", "" };
145         size_t baselen = path->len;
146         struct stat st;
147         int i;
148
149         for (i = 0; i < ARRAY_SIZE(suffix); i++) {
150                 strbuf_setlen(path, baselen);
151                 strbuf_addstr(path, suffix[i]);
152                 if (stat(path->buf, &st))
153                         continue;
154                 if (S_ISDIR(st.st_mode) && is_git_directory(path->buf)) {
155                         *is_bundle = 0;
156                         return path->buf;
157                 } else if (S_ISREG(st.st_mode) && st.st_size > 8) {
158                         /* Is it a "gitfile"? */
159                         char signature[8];
160                         const char *dst;
161                         int len, fd = open(path->buf, O_RDONLY);
162                         if (fd < 0)
163                                 continue;
164                         len = read_in_full(fd, signature, 8);
165                         close(fd);
166                         if (len != 8 || strncmp(signature, "gitdir: ", 8))
167                                 continue;
168                         dst = read_gitfile(path->buf);
169                         if (dst) {
170                                 *is_bundle = 0;
171                                 return dst;
172                         }
173                 }
174         }
175
176         for (i = 0; i < ARRAY_SIZE(bundle_suffix); i++) {
177                 strbuf_setlen(path, baselen);
178                 strbuf_addstr(path, bundle_suffix[i]);
179                 if (!stat(path->buf, &st) && S_ISREG(st.st_mode)) {
180                         *is_bundle = 1;
181                         return path->buf;
182                 }
183         }
184
185         return NULL;
186 }
187
188 static char *get_repo_path(const char *repo, int *is_bundle)
189 {
190         struct strbuf path = STRBUF_INIT;
191         const char *raw;
192         char *canon;
193
194         strbuf_addstr(&path, repo);
195         raw = get_repo_path_1(&path, is_bundle);
196         canon = raw ? absolute_pathdup(raw) : NULL;
197         strbuf_release(&path);
198         return canon;
199 }
200
201 static char *guess_dir_name(const char *repo, int is_bundle, int is_bare)
202 {
203         const char *end = repo + strlen(repo), *start, *ptr;
204         size_t len;
205         char *dir;
206
207         /*
208          * Skip scheme.
209          */
210         start = strstr(repo, "://");
211         if (start == NULL)
212                 start = repo;
213         else
214                 start += 3;
215
216         /*
217          * Skip authentication data. The stripping does happen
218          * greedily, such that we strip up to the last '@' inside
219          * the host part.
220          */
221         for (ptr = start; ptr < end && !is_dir_sep(*ptr); ptr++) {
222                 if (*ptr == '@')
223                         start = ptr + 1;
224         }
225
226         /*
227          * Strip trailing spaces, slashes and /.git
228          */
229         while (start < end && (is_dir_sep(end[-1]) || isspace(end[-1])))
230                 end--;
231         if (end - start > 5 && is_dir_sep(end[-5]) &&
232             !strncmp(end - 4, ".git", 4)) {
233                 end -= 5;
234                 while (start < end && is_dir_sep(end[-1]))
235                         end--;
236         }
237
238         /*
239          * Strip trailing port number if we've got only a
240          * hostname (that is, there is no dir separator but a
241          * colon). This check is required such that we do not
242          * strip URI's like '/foo/bar:2222.git', which should
243          * result in a dir '2222' being guessed due to backwards
244          * compatibility.
245          */
246         if (memchr(start, '/', end - start) == NULL
247             && memchr(start, ':', end - start) != NULL) {
248                 ptr = end;
249                 while (start < ptr && isdigit(ptr[-1]) && ptr[-1] != ':')
250                         ptr--;
251                 if (start < ptr && ptr[-1] == ':')
252                         end = ptr - 1;
253         }
254
255         /*
256          * Find last component. To remain backwards compatible we
257          * also regard colons as path separators, such that
258          * cloning a repository 'foo:bar.git' would result in a
259          * directory 'bar' being guessed.
260          */
261         ptr = end;
262         while (start < ptr && !is_dir_sep(ptr[-1]) && ptr[-1] != ':')
263                 ptr--;
264         start = ptr;
265
266         /*
267          * Strip .{bundle,git}.
268          */
269         len = end - start;
270         strip_suffix_mem(start, &len, is_bundle ? ".bundle" : ".git");
271
272         if (!len || (len == 1 && *start == '/'))
273                 die(_("No directory name could be guessed.\n"
274                       "Please specify a directory on the command line"));
275
276         if (is_bare)
277                 dir = xstrfmt("%.*s.git", (int)len, start);
278         else
279                 dir = xstrndup(start, len);
280         /*
281          * Replace sequences of 'control' characters and whitespace
282          * with one ascii space, remove leading and trailing spaces.
283          */
284         if (*dir) {
285                 char *out = dir;
286                 int prev_space = 1 /* strip leading whitespace */;
287                 for (end = dir; *end; ++end) {
288                         char ch = *end;
289                         if ((unsigned char)ch < '\x20')
290                                 ch = '\x20';
291                         if (isspace(ch)) {
292                                 if (prev_space)
293                                         continue;
294                                 prev_space = 1;
295                         } else
296                                 prev_space = 0;
297                         *out++ = ch;
298                 }
299                 *out = '\0';
300                 if (out > dir && prev_space)
301                         out[-1] = '\0';
302         }
303         return dir;
304 }
305
306 static void strip_trailing_slashes(char *dir)
307 {
308         char *end = dir + strlen(dir);
309
310         while (dir < end - 1 && is_dir_sep(end[-1]))
311                 end--;
312         *end = '\0';
313 }
314
315 static int add_one_reference(struct string_list_item *item, void *cb_data)
316 {
317         struct strbuf err = STRBUF_INIT;
318         int *required = cb_data;
319         char *ref_git = compute_alternate_path(item->string, &err);
320
321         if (!ref_git) {
322                 if (*required)
323                         die("%s", err.buf);
324                 else
325                         fprintf(stderr,
326                                 _("info: Could not add alternate for '%s': %s\n"),
327                                 item->string, err.buf);
328         } else {
329                 struct strbuf sb = STRBUF_INIT;
330                 strbuf_addf(&sb, "%s/objects", ref_git);
331                 add_to_alternates_file(sb.buf);
332                 strbuf_release(&sb);
333         }
334
335         strbuf_release(&err);
336         free(ref_git);
337         return 0;
338 }
339
340 static void setup_reference(void)
341 {
342         int required = 1;
343         for_each_string_list(&option_required_reference,
344                              add_one_reference, &required);
345         required = 0;
346         for_each_string_list(&option_optional_reference,
347                              add_one_reference, &required);
348 }
349
350 static void copy_alternates(struct strbuf *src, struct strbuf *dst,
351                             const char *src_repo)
352 {
353         /*
354          * Read from the source objects/info/alternates file
355          * and copy the entries to corresponding file in the
356          * destination repository with add_to_alternates_file().
357          * Both src and dst have "$path/objects/info/alternates".
358          *
359          * Instead of copying bit-for-bit from the original,
360          * we need to append to existing one so that the already
361          * created entry via "clone -s" is not lost, and also
362          * to turn entries with paths relative to the original
363          * absolute, so that they can be used in the new repository.
364          */
365         FILE *in = xfopen(src->buf, "r");
366         struct strbuf line = STRBUF_INIT;
367
368         while (strbuf_getline(&line, in) != EOF) {
369                 char *abs_path;
370                 if (!line.len || line.buf[0] == '#')
371                         continue;
372                 if (is_absolute_path(line.buf)) {
373                         add_to_alternates_file(line.buf);
374                         continue;
375                 }
376                 abs_path = mkpathdup("%s/objects/%s", src_repo, line.buf);
377                 if (!normalize_path_copy(abs_path, abs_path))
378                         add_to_alternates_file(abs_path);
379                 else
380                         warning("skipping invalid relative alternate: %s/%s",
381                                 src_repo, line.buf);
382                 free(abs_path);
383         }
384         strbuf_release(&line);
385         fclose(in);
386 }
387
388 static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
389                                    const char *src_repo, int src_baselen)
390 {
391         struct dirent *de;
392         struct stat buf;
393         int src_len, dest_len;
394         DIR *dir;
395
396         dir = opendir(src->buf);
397         if (!dir)
398                 die_errno(_("failed to open '%s'"), src->buf);
399
400         if (mkdir(dest->buf, 0777)) {
401                 if (errno != EEXIST)
402                         die_errno(_("failed to create directory '%s'"), dest->buf);
403                 else if (stat(dest->buf, &buf))
404                         die_errno(_("failed to stat '%s'"), dest->buf);
405                 else if (!S_ISDIR(buf.st_mode))
406                         die(_("%s exists and is not a directory"), dest->buf);
407         }
408
409         strbuf_addch(src, '/');
410         src_len = src->len;
411         strbuf_addch(dest, '/');
412         dest_len = dest->len;
413
414         while ((de = readdir(dir)) != NULL) {
415                 strbuf_setlen(src, src_len);
416                 strbuf_addstr(src, de->d_name);
417                 strbuf_setlen(dest, dest_len);
418                 strbuf_addstr(dest, de->d_name);
419                 if (stat(src->buf, &buf)) {
420                         warning (_("failed to stat %s\n"), src->buf);
421                         continue;
422                 }
423                 if (S_ISDIR(buf.st_mode)) {
424                         if (de->d_name[0] != '.')
425                                 copy_or_link_directory(src, dest,
426                                                        src_repo, src_baselen);
427                         continue;
428                 }
429
430                 /* Files that cannot be copied bit-for-bit... */
431                 if (!strcmp(src->buf + src_baselen, "/info/alternates")) {
432                         copy_alternates(src, dest, src_repo);
433                         continue;
434                 }
435
436                 if (unlink(dest->buf) && errno != ENOENT)
437                         die_errno(_("failed to unlink '%s'"), dest->buf);
438                 if (!option_no_hardlinks) {
439                         if (!link(src->buf, dest->buf))
440                                 continue;
441                         if (option_local > 0)
442                                 die_errno(_("failed to create link '%s'"), dest->buf);
443                         option_no_hardlinks = 1;
444                 }
445                 if (copy_file_with_time(dest->buf, src->buf, 0666))
446                         die_errno(_("failed to copy file to '%s'"), dest->buf);
447         }
448         closedir(dir);
449 }
450
451 static void clone_local(const char *src_repo, const char *dest_repo)
452 {
453         if (option_shared) {
454                 struct strbuf alt = STRBUF_INIT;
455                 strbuf_addf(&alt, "%s/objects", src_repo);
456                 add_to_alternates_file(alt.buf);
457                 strbuf_release(&alt);
458         } else {
459                 struct strbuf src = STRBUF_INIT;
460                 struct strbuf dest = STRBUF_INIT;
461                 get_common_dir(&src, src_repo);
462                 get_common_dir(&dest, dest_repo);
463                 strbuf_addstr(&src, "/objects");
464                 strbuf_addstr(&dest, "/objects");
465                 copy_or_link_directory(&src, &dest, src_repo, src.len);
466                 strbuf_release(&src);
467                 strbuf_release(&dest);
468         }
469
470         if (0 <= option_verbosity)
471                 fprintf(stderr, _("done.\n"));
472 }
473
474 static const char *junk_work_tree;
475 static const char *junk_git_dir;
476 static enum {
477         JUNK_LEAVE_NONE,
478         JUNK_LEAVE_REPO,
479         JUNK_LEAVE_ALL
480 } junk_mode = JUNK_LEAVE_NONE;
481
482 static const char junk_leave_repo_msg[] =
483 N_("Clone succeeded, but checkout failed.\n"
484    "You can inspect what was checked out with 'git status'\n"
485    "and retry the checkout with 'git checkout -f HEAD'\n");
486
487 static void remove_junk(void)
488 {
489         struct strbuf sb = STRBUF_INIT;
490
491         switch (junk_mode) {
492         case JUNK_LEAVE_REPO:
493                 warning("%s", _(junk_leave_repo_msg));
494                 /* fall-through */
495         case JUNK_LEAVE_ALL:
496                 return;
497         default:
498                 /* proceed to removal */
499                 break;
500         }
501
502         if (junk_git_dir) {
503                 strbuf_addstr(&sb, junk_git_dir);
504                 remove_dir_recursively(&sb, 0);
505                 strbuf_reset(&sb);
506         }
507         if (junk_work_tree) {
508                 strbuf_addstr(&sb, junk_work_tree);
509                 remove_dir_recursively(&sb, 0);
510         }
511         strbuf_release(&sb);
512 }
513
514 static void remove_junk_on_signal(int signo)
515 {
516         remove_junk();
517         sigchain_pop(signo);
518         raise(signo);
519 }
520
521 static struct ref *find_remote_branch(const struct ref *refs, const char *branch)
522 {
523         struct ref *ref;
524         struct strbuf head = STRBUF_INIT;
525         strbuf_addstr(&head, "refs/heads/");
526         strbuf_addstr(&head, branch);
527         ref = find_ref_by_name(refs, head.buf);
528         strbuf_release(&head);
529
530         if (ref)
531                 return ref;
532
533         strbuf_addstr(&head, "refs/tags/");
534         strbuf_addstr(&head, branch);
535         ref = find_ref_by_name(refs, head.buf);
536         strbuf_release(&head);
537
538         return ref;
539 }
540
541 static struct ref *wanted_peer_refs(const struct ref *refs,
542                 struct refspec *refspec)
543 {
544         struct ref *head = copy_ref(find_ref_by_name(refs, "HEAD"));
545         struct ref *local_refs = head;
546         struct ref **tail = head ? &head->next : &local_refs;
547
548         if (option_single_branch) {
549                 struct ref *remote_head = NULL;
550
551                 if (!option_branch)
552                         remote_head = guess_remote_head(head, refs, 0);
553                 else {
554                         local_refs = NULL;
555                         tail = &local_refs;
556                         remote_head = copy_ref(find_remote_branch(refs, option_branch));
557                 }
558
559                 if (!remote_head && option_branch)
560                         warning(_("Could not find remote branch %s to clone."),
561                                 option_branch);
562                 else {
563                         get_fetch_map(remote_head, refspec, &tail, 0);
564
565                         /* if --branch=tag, pull the requested tag explicitly */
566                         get_fetch_map(remote_head, tag_refspec, &tail, 0);
567                 }
568         } else
569                 get_fetch_map(refs, refspec, &tail, 0);
570
571         if (!option_mirror && !option_single_branch && !option_no_tags)
572                 get_fetch_map(refs, tag_refspec, &tail, 0);
573
574         return local_refs;
575 }
576
577 static void write_remote_refs(const struct ref *local_refs)
578 {
579         const struct ref *r;
580
581         struct ref_transaction *t;
582         struct strbuf err = STRBUF_INIT;
583
584         t = ref_transaction_begin(&err);
585         if (!t)
586                 die("%s", err.buf);
587
588         for (r = local_refs; r; r = r->next) {
589                 if (!r->peer_ref)
590                         continue;
591                 if (ref_transaction_create(t, r->peer_ref->name, &r->old_oid,
592                                            0, NULL, &err))
593                         die("%s", err.buf);
594         }
595
596         if (initial_ref_transaction_commit(t, &err))
597                 die("%s", err.buf);
598
599         strbuf_release(&err);
600         ref_transaction_free(t);
601 }
602
603 static void write_followtags(const struct ref *refs, const char *msg)
604 {
605         const struct ref *ref;
606         for (ref = refs; ref; ref = ref->next) {
607                 if (!starts_with(ref->name, "refs/tags/"))
608                         continue;
609                 if (ends_with(ref->name, "^{}"))
610                         continue;
611                 if (!has_object_file(&ref->old_oid))
612                         continue;
613                 update_ref(msg, ref->name, &ref->old_oid, NULL, 0,
614                            UPDATE_REFS_DIE_ON_ERR);
615         }
616 }
617
618 static int iterate_ref_map(void *cb_data, unsigned char sha1[20])
619 {
620         struct ref **rm = cb_data;
621         struct ref *ref = *rm;
622
623         /*
624          * Skip anything missing a peer_ref, which we are not
625          * actually going to write a ref for.
626          */
627         while (ref && !ref->peer_ref)
628                 ref = ref->next;
629         /* Returning -1 notes "end of list" to the caller. */
630         if (!ref)
631                 return -1;
632
633         hashcpy(sha1, ref->old_oid.hash);
634         *rm = ref->next;
635         return 0;
636 }
637
638 static void update_remote_refs(const struct ref *refs,
639                                const struct ref *mapped_refs,
640                                const struct ref *remote_head_points_at,
641                                const char *branch_top,
642                                const char *msg,
643                                struct transport *transport,
644                                int check_connectivity)
645 {
646         const struct ref *rm = mapped_refs;
647
648         if (check_connectivity) {
649                 struct check_connected_options opt = CHECK_CONNECTED_INIT;
650
651                 opt.transport = transport;
652                 opt.progress = transport->progress;
653
654                 if (check_connected(iterate_ref_map, &rm, &opt))
655                         die(_("remote did not send all necessary objects"));
656         }
657
658         if (refs) {
659                 write_remote_refs(mapped_refs);
660                 if (option_single_branch && !option_no_tags)
661                         write_followtags(refs, msg);
662         }
663
664         if (remote_head_points_at && !option_bare) {
665                 struct strbuf head_ref = STRBUF_INIT;
666                 strbuf_addstr(&head_ref, branch_top);
667                 strbuf_addstr(&head_ref, "HEAD");
668                 if (create_symref(head_ref.buf,
669                                   remote_head_points_at->peer_ref->name,
670                                   msg) < 0)
671                         die(_("unable to update %s"), head_ref.buf);
672                 strbuf_release(&head_ref);
673         }
674 }
675
676 static void update_head(const struct ref *our, const struct ref *remote,
677                         const char *msg)
678 {
679         const char *head;
680         if (our && skip_prefix(our->name, "refs/heads/", &head)) {
681                 /* Local default branch link */
682                 if (create_symref("HEAD", our->name, NULL) < 0)
683                         die(_("unable to update HEAD"));
684                 if (!option_bare) {
685                         update_ref(msg, "HEAD", &our->old_oid, NULL, 0,
686                                    UPDATE_REFS_DIE_ON_ERR);
687                         install_branch_config(0, head, option_origin, our->name);
688                 }
689         } else if (our) {
690                 struct commit *c = lookup_commit_reference(&our->old_oid);
691                 /* --branch specifies a non-branch (i.e. tags), detach HEAD */
692                 update_ref(msg, "HEAD", &c->object.oid, NULL, REF_NODEREF,
693                            UPDATE_REFS_DIE_ON_ERR);
694         } else if (remote) {
695                 /*
696                  * We know remote HEAD points to a non-branch, or
697                  * HEAD points to a branch but we don't know which one.
698                  * Detach HEAD in all these cases.
699                  */
700                 update_ref(msg, "HEAD", &remote->old_oid, NULL, REF_NODEREF,
701                            UPDATE_REFS_DIE_ON_ERR);
702         }
703 }
704
705 static int checkout(int submodule_progress)
706 {
707         struct object_id oid;
708         char *head;
709         struct lock_file *lock_file;
710         struct unpack_trees_options opts;
711         struct tree *tree;
712         struct tree_desc t;
713         int err = 0;
714
715         if (option_no_checkout)
716                 return 0;
717
718         head = resolve_refdup("HEAD", RESOLVE_REF_READING, oid.hash, NULL);
719         if (!head) {
720                 warning(_("remote HEAD refers to nonexistent ref, "
721                           "unable to checkout.\n"));
722                 return 0;
723         }
724         if (!strcmp(head, "HEAD")) {
725                 if (advice_detached_head)
726                         detach_advice(oid_to_hex(&oid));
727         } else {
728                 if (!starts_with(head, "refs/heads/"))
729                         die(_("HEAD not found below refs/heads!"));
730         }
731         free(head);
732
733         /* We need to be in the new work tree for the checkout */
734         setup_work_tree();
735
736         lock_file = xcalloc(1, sizeof(struct lock_file));
737         hold_locked_index(lock_file, LOCK_DIE_ON_ERROR);
738
739         memset(&opts, 0, sizeof opts);
740         opts.update = 1;
741         opts.merge = 1;
742         opts.fn = oneway_merge;
743         opts.verbose_update = (option_verbosity >= 0);
744         opts.src_index = &the_index;
745         opts.dst_index = &the_index;
746
747         tree = parse_tree_indirect(&oid);
748         parse_tree(tree);
749         init_tree_desc(&t, tree->buffer, tree->size);
750         if (unpack_trees(1, &t, &opts) < 0)
751                 die(_("unable to checkout working tree"));
752
753         if (write_locked_index(&the_index, lock_file, COMMIT_LOCK))
754                 die(_("unable to write new index file"));
755
756         err |= run_hook_le(NULL, "post-checkout", sha1_to_hex(null_sha1),
757                            oid_to_hex(&oid), "1", NULL);
758
759         if (!err && (option_recurse_submodules.nr > 0)) {
760                 struct argv_array args = ARGV_ARRAY_INIT;
761                 argv_array_pushl(&args, "submodule", "update", "--init", "--recursive", NULL);
762
763                 if (option_shallow_submodules == 1)
764                         argv_array_push(&args, "--depth=1");
765
766                 if (max_jobs != -1)
767                         argv_array_pushf(&args, "--jobs=%d", max_jobs);
768
769                 if (submodule_progress)
770                         argv_array_push(&args, "--progress");
771
772                 if (option_verbosity < 0)
773                         argv_array_push(&args, "--quiet");
774
775                 err = run_command_v_opt(args.argv, RUN_GIT_CMD);
776                 argv_array_clear(&args);
777         }
778
779         return err;
780 }
781
782 static int write_one_config(const char *key, const char *value, void *data)
783 {
784         return git_config_set_multivar_gently(key,
785                                               value ? value : "true",
786                                               CONFIG_REGEX_NONE, 0);
787 }
788
789 static void write_config(struct string_list *config)
790 {
791         int i;
792
793         for (i = 0; i < config->nr; i++) {
794                 if (git_config_parse_parameter(config->items[i].string,
795                                                write_one_config, NULL) < 0)
796                         die(_("unable to write parameters to config file"));
797         }
798 }
799
800 static void write_refspec_config(const char *src_ref_prefix,
801                 const struct ref *our_head_points_at,
802                 const struct ref *remote_head_points_at,
803                 struct strbuf *branch_top)
804 {
805         struct strbuf key = STRBUF_INIT;
806         struct strbuf value = STRBUF_INIT;
807
808         if (option_mirror || !option_bare) {
809                 if (option_single_branch && !option_mirror) {
810                         if (option_branch) {
811                                 if (starts_with(our_head_points_at->name, "refs/tags/"))
812                                         strbuf_addf(&value, "+%s:%s", our_head_points_at->name,
813                                                 our_head_points_at->name);
814                                 else
815                                         strbuf_addf(&value, "+%s:%s%s", our_head_points_at->name,
816                                                 branch_top->buf, option_branch);
817                         } else if (remote_head_points_at) {
818                                 const char *head = remote_head_points_at->name;
819                                 if (!skip_prefix(head, "refs/heads/", &head))
820                                         die("BUG: remote HEAD points at non-head?");
821
822                                 strbuf_addf(&value, "+%s:%s%s", remote_head_points_at->name,
823                                                 branch_top->buf, head);
824                         }
825                         /*
826                          * otherwise, the next "git fetch" will
827                          * simply fetch from HEAD without updating
828                          * any remote-tracking branch, which is what
829                          * we want.
830                          */
831                 } else {
832                         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top->buf);
833                 }
834                 /* Configure the remote */
835                 if (value.len) {
836                         strbuf_addf(&key, "remote.%s.fetch", option_origin);
837                         git_config_set_multivar(key.buf, value.buf, "^$", 0);
838                         strbuf_reset(&key);
839
840                         if (option_mirror) {
841                                 strbuf_addf(&key, "remote.%s.mirror", option_origin);
842                                 git_config_set(key.buf, "true");
843                                 strbuf_reset(&key);
844                         }
845                 }
846         }
847
848         strbuf_release(&key);
849         strbuf_release(&value);
850 }
851
852 static void dissociate_from_references(void)
853 {
854         static const char* argv[] = { "repack", "-a", "-d", NULL };
855         char *alternates = git_pathdup("objects/info/alternates");
856
857         if (!access(alternates, F_OK)) {
858                 if (run_command_v_opt(argv, RUN_GIT_CMD|RUN_COMMAND_NO_STDIN))
859                         die(_("cannot repack to clean up"));
860                 if (unlink(alternates) && errno != ENOENT)
861                         die_errno(_("cannot unlink temporary alternates file"));
862         }
863         free(alternates);
864 }
865
866 int cmd_clone(int argc, const char **argv, const char *prefix)
867 {
868         int is_bundle = 0, is_local;
869         struct stat buf;
870         const char *repo_name, *repo, *work_tree, *git_dir;
871         char *path, *dir;
872         int dest_exists;
873         const struct ref *refs, *remote_head;
874         const struct ref *remote_head_points_at;
875         const struct ref *our_head_points_at;
876         struct ref *mapped_refs;
877         const struct ref *ref;
878         struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
879         struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
880         struct transport *transport = NULL;
881         const char *src_ref_prefix = "refs/heads/";
882         struct remote *remote;
883         int err = 0, complete_refs_before_fetch = 1;
884         int submodule_progress;
885
886         struct refspec *refspec;
887         const char *fetch_pattern;
888
889         packet_trace_identity("clone");
890         argc = parse_options(argc, argv, prefix, builtin_clone_options,
891                              builtin_clone_usage, 0);
892
893         if (argc > 2)
894                 usage_msg_opt(_("Too many arguments."),
895                         builtin_clone_usage, builtin_clone_options);
896
897         if (argc == 0)
898                 usage_msg_opt(_("You must specify a repository to clone."),
899                         builtin_clone_usage, builtin_clone_options);
900
901         if (option_depth || option_since || option_not.nr)
902                 deepen = 1;
903         if (option_single_branch == -1)
904                 option_single_branch = deepen ? 1 : 0;
905
906         if (option_mirror)
907                 option_bare = 1;
908
909         if (option_bare) {
910                 if (option_origin)
911                         die(_("--bare and --origin %s options are incompatible."),
912                             option_origin);
913                 if (real_git_dir)
914                         die(_("--bare and --separate-git-dir are incompatible."));
915                 option_no_checkout = 1;
916         }
917
918         if (!option_origin)
919                 option_origin = "origin";
920
921         repo_name = argv[0];
922
923         path = get_repo_path(repo_name, &is_bundle);
924         if (path)
925                 repo = absolute_pathdup(repo_name);
926         else if (!strchr(repo_name, ':'))
927                 die(_("repository '%s' does not exist"), repo_name);
928         else
929                 repo = repo_name;
930
931         /* no need to be strict, transport_set_option() will validate it again */
932         if (option_depth && atoi(option_depth) < 1)
933                 die(_("depth %s is not a positive number"), option_depth);
934
935         if (argc == 2)
936                 dir = xstrdup(argv[1]);
937         else
938                 dir = guess_dir_name(repo_name, is_bundle, option_bare);
939         strip_trailing_slashes(dir);
940
941         dest_exists = !stat(dir, &buf);
942         if (dest_exists && !is_empty_dir(dir))
943                 die(_("destination path '%s' already exists and is not "
944                         "an empty directory."), dir);
945
946         strbuf_addf(&reflog_msg, "clone: from %s", repo);
947
948         if (option_bare)
949                 work_tree = NULL;
950         else {
951                 work_tree = getenv("GIT_WORK_TREE");
952                 if (work_tree && !stat(work_tree, &buf))
953                         die(_("working tree '%s' already exists."), work_tree);
954         }
955
956         if (option_bare || work_tree)
957                 git_dir = xstrdup(dir);
958         else {
959                 work_tree = dir;
960                 git_dir = mkpathdup("%s/.git", dir);
961         }
962
963         atexit(remove_junk);
964         sigchain_push_common(remove_junk_on_signal);
965
966         if (!option_bare) {
967                 if (safe_create_leading_directories_const(work_tree) < 0)
968                         die_errno(_("could not create leading directories of '%s'"),
969                                   work_tree);
970                 if (!dest_exists && mkdir(work_tree, 0777))
971                         die_errno(_("could not create work tree dir '%s'"),
972                                   work_tree);
973                 junk_work_tree = work_tree;
974                 set_git_work_tree(work_tree);
975         }
976
977         junk_git_dir = real_git_dir ? real_git_dir : git_dir;
978         if (safe_create_leading_directories_const(git_dir) < 0)
979                 die(_("could not create leading directories of '%s'"), git_dir);
980
981         if (0 <= option_verbosity) {
982                 if (option_bare)
983                         fprintf(stderr, _("Cloning into bare repository '%s'...\n"), dir);
984                 else
985                         fprintf(stderr, _("Cloning into '%s'...\n"), dir);
986         }
987
988         if (option_recurse_submodules.nr > 0) {
989                 struct string_list_item *item;
990                 struct strbuf sb = STRBUF_INIT;
991
992                 /* remove duplicates */
993                 string_list_sort(&option_recurse_submodules);
994                 string_list_remove_duplicates(&option_recurse_submodules, 0);
995
996                 /*
997                  * NEEDSWORK: In a multi-working-tree world, this needs to be
998                  * set in the per-worktree config.
999                  */
1000                 for_each_string_list_item(item, &option_recurse_submodules) {
1001                         strbuf_addf(&sb, "submodule.active=%s",
1002                                     item->string);
1003                         string_list_append(&option_config,
1004                                            strbuf_detach(&sb, NULL));
1005                 }
1006
1007                 if (option_required_reference.nr &&
1008                     option_optional_reference.nr)
1009                         die(_("clone --recursive is not compatible with "
1010                               "both --reference and --reference-if-able"));
1011                 else if (option_required_reference.nr) {
1012                         string_list_append(&option_config,
1013                                 "submodule.alternateLocation=superproject");
1014                         string_list_append(&option_config,
1015                                 "submodule.alternateErrorStrategy=die");
1016                 } else if (option_optional_reference.nr) {
1017                         string_list_append(&option_config,
1018                                 "submodule.alternateLocation=superproject");
1019                         string_list_append(&option_config,
1020                                 "submodule.alternateErrorStrategy=info");
1021                 }
1022         }
1023
1024         init_db(git_dir, real_git_dir, option_template, INIT_DB_QUIET);
1025
1026         if (real_git_dir)
1027                 git_dir = real_git_dir;
1028
1029         write_config(&option_config);
1030
1031         git_config(git_default_config, NULL);
1032
1033         if (option_bare) {
1034                 if (option_mirror)
1035                         src_ref_prefix = "refs/";
1036                 strbuf_addstr(&branch_top, src_ref_prefix);
1037
1038                 git_config_set("core.bare", "true");
1039         } else {
1040                 strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
1041         }
1042
1043         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
1044         strbuf_addf(&key, "remote.%s.url", option_origin);
1045         git_config_set(key.buf, repo);
1046         strbuf_reset(&key);
1047
1048         if (option_no_tags) {
1049                 strbuf_addf(&key, "remote.%s.tagOpt", option_origin);
1050                 git_config_set(key.buf, "--no-tags");
1051                 strbuf_reset(&key);
1052         }
1053
1054         if (option_required_reference.nr || option_optional_reference.nr)
1055                 setup_reference();
1056
1057         fetch_pattern = value.buf;
1058         refspec = parse_fetch_refspec(1, &fetch_pattern);
1059
1060         strbuf_reset(&value);
1061
1062         remote = remote_get(option_origin);
1063         transport = transport_get(remote, remote->url[0]);
1064         transport_set_verbosity(transport, option_verbosity, option_progress);
1065         transport->family = family;
1066
1067         path = get_repo_path(remote->url[0], &is_bundle);
1068         is_local = option_local != 0 && path && !is_bundle;
1069         if (is_local) {
1070                 if (option_depth)
1071                         warning(_("--depth is ignored in local clones; use file:// instead."));
1072                 if (option_since)
1073                         warning(_("--shallow-since is ignored in local clones; use file:// instead."));
1074                 if (option_not.nr)
1075                         warning(_("--shallow-exclude is ignored in local clones; use file:// instead."));
1076                 if (!access(mkpath("%s/shallow", path), F_OK)) {
1077                         if (option_local > 0)
1078                                 warning(_("source repository is shallow, ignoring --local"));
1079                         is_local = 0;
1080                 }
1081         }
1082         if (option_local > 0 && !is_local)
1083                 warning(_("--local is ignored"));
1084         transport->cloning = 1;
1085
1086         if (!transport->get_refs_list || (!is_local && !transport->fetch))
1087                 die(_("Don't know how to clone %s"), transport->url);
1088
1089         transport_set_option(transport, TRANS_OPT_KEEP, "yes");
1090
1091         if (option_depth)
1092                 transport_set_option(transport, TRANS_OPT_DEPTH,
1093                                      option_depth);
1094         if (option_since)
1095                 transport_set_option(transport, TRANS_OPT_DEEPEN_SINCE,
1096                                      option_since);
1097         if (option_not.nr)
1098                 transport_set_option(transport, TRANS_OPT_DEEPEN_NOT,
1099                                      (const char *)&option_not);
1100         if (option_single_branch)
1101                 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
1102
1103         if (option_upload_pack)
1104                 transport_set_option(transport, TRANS_OPT_UPLOADPACK,
1105                                      option_upload_pack);
1106
1107         if (transport->smart_options && !deepen)
1108                 transport->smart_options->check_self_contained_and_connected = 1;
1109
1110         refs = transport_get_remote_refs(transport);
1111
1112         if (refs) {
1113                 mapped_refs = wanted_peer_refs(refs, refspec);
1114                 /*
1115                  * transport_get_remote_refs() may return refs with null sha-1
1116                  * in mapped_refs (see struct transport->get_refs_list
1117                  * comment). In that case we need fetch it early because
1118                  * remote_head code below relies on it.
1119                  *
1120                  * for normal clones, transport_get_remote_refs() should
1121                  * return reliable ref set, we can delay cloning until after
1122                  * remote HEAD check.
1123                  */
1124                 for (ref = refs; ref; ref = ref->next)
1125                         if (is_null_oid(&ref->old_oid)) {
1126                                 complete_refs_before_fetch = 0;
1127                                 break;
1128                         }
1129
1130                 if (!is_local && !complete_refs_before_fetch)
1131                         transport_fetch_refs(transport, mapped_refs);
1132
1133                 remote_head = find_ref_by_name(refs, "HEAD");
1134                 remote_head_points_at =
1135                         guess_remote_head(remote_head, mapped_refs, 0);
1136
1137                 if (option_branch) {
1138                         our_head_points_at =
1139                                 find_remote_branch(mapped_refs, option_branch);
1140
1141                         if (!our_head_points_at)
1142                                 die(_("Remote branch %s not found in upstream %s"),
1143                                     option_branch, option_origin);
1144                 }
1145                 else
1146                         our_head_points_at = remote_head_points_at;
1147         }
1148         else {
1149                 if (option_branch)
1150                         die(_("Remote branch %s not found in upstream %s"),
1151                                         option_branch, option_origin);
1152
1153                 warning(_("You appear to have cloned an empty repository."));
1154                 mapped_refs = NULL;
1155                 our_head_points_at = NULL;
1156                 remote_head_points_at = NULL;
1157                 remote_head = NULL;
1158                 option_no_checkout = 1;
1159                 if (!option_bare)
1160                         install_branch_config(0, "master", option_origin,
1161                                               "refs/heads/master");
1162         }
1163
1164         write_refspec_config(src_ref_prefix, our_head_points_at,
1165                         remote_head_points_at, &branch_top);
1166
1167         if (is_local)
1168                 clone_local(path, git_dir);
1169         else if (refs && complete_refs_before_fetch)
1170                 transport_fetch_refs(transport, mapped_refs);
1171
1172         update_remote_refs(refs, mapped_refs, remote_head_points_at,
1173                            branch_top.buf, reflog_msg.buf, transport, !is_local);
1174
1175         update_head(our_head_points_at, remote_head, reflog_msg.buf);
1176
1177         /*
1178          * We want to show progress for recursive submodule clones iff
1179          * we did so for the main clone. But only the transport knows
1180          * the final decision for this flag, so we need to rescue the value
1181          * before we free the transport.
1182          */
1183         submodule_progress = transport->progress;
1184
1185         transport_unlock_pack(transport);
1186         transport_disconnect(transport);
1187
1188         if (option_dissociate) {
1189                 close_all_packs();
1190                 dissociate_from_references();
1191         }
1192
1193         junk_mode = JUNK_LEAVE_REPO;
1194         err = checkout(submodule_progress);
1195
1196         strbuf_release(&reflog_msg);
1197         strbuf_release(&branch_top);
1198         strbuf_release(&key);
1199         strbuf_release(&value);
1200         junk_mode = JUNK_LEAVE_ALL;
1201
1202         free(refspec);
1203         return err;
1204 }