rm: remove unneeded null pointer check
[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 "parse-options.h"
13 #include "fetch-pack.h"
14 #include "refs.h"
15 #include "tree.h"
16 #include "tree-walk.h"
17 #include "unpack-trees.h"
18 #include "transport.h"
19 #include "strbuf.h"
20 #include "dir.h"
21 #include "sigchain.h"
22 #include "branch.h"
23 #include "remote.h"
24 #include "run-command.h"
25 #include "connected.h"
26
27 /*
28  * Overall FIXMEs:
29  *  - respect DB_ENVIRONMENT for .git/objects.
30  *
31  * Implementation notes:
32  *  - dropping use-separate-remote and no-separate-remote compatibility
33  *
34  */
35 static const char * const builtin_clone_usage[] = {
36         N_("git clone [options] [--] <repo> [<dir>]"),
37         NULL
38 };
39
40 static int option_no_checkout, option_bare, option_mirror, option_single_branch = -1;
41 static int option_local = -1, option_no_hardlinks, option_shared, option_recursive;
42 static char *option_template, *option_depth;
43 static char *option_origin = NULL;
44 static char *option_branch = NULL;
45 static const char *real_git_dir;
46 static char *option_upload_pack = "git-upload-pack";
47 static int option_verbosity;
48 static int option_progress = -1;
49 static struct string_list option_config;
50 static struct string_list option_reference;
51
52 static int opt_parse_reference(const struct option *opt, const char *arg, int unset)
53 {
54         struct string_list *option_reference = opt->value;
55         if (!arg)
56                 return -1;
57         string_list_append(option_reference, arg);
58         return 0;
59 }
60
61 static struct option builtin_clone_options[] = {
62         OPT__VERBOSITY(&option_verbosity),
63         OPT_BOOL(0, "progress", &option_progress,
64                  N_("force progress reporting")),
65         OPT_BOOLEAN('n', "no-checkout", &option_no_checkout,
66                     N_("don't create a checkout")),
67         OPT_BOOLEAN(0, "bare", &option_bare, N_("create a bare repository")),
68         { OPTION_BOOLEAN, 0, "naked", &option_bare, NULL,
69                 N_("create a bare repository"),
70                 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
71         OPT_BOOLEAN(0, "mirror", &option_mirror,
72                     N_("create a mirror repository (implies bare)")),
73         OPT_BOOL('l', "local", &option_local,
74                 N_("to clone from a local repository")),
75         OPT_BOOLEAN(0, "no-hardlinks", &option_no_hardlinks,
76                     N_("don't use local hardlinks, always copy")),
77         OPT_BOOLEAN('s', "shared", &option_shared,
78                     N_("setup as shared repository")),
79         OPT_BOOLEAN(0, "recursive", &option_recursive,
80                     N_("initialize submodules in the clone")),
81         OPT_BOOLEAN(0, "recurse-submodules", &option_recursive,
82                     N_("initialize submodules in the clone")),
83         OPT_STRING(0, "template", &option_template, N_("template-directory"),
84                    N_("directory from which templates will be used")),
85         OPT_CALLBACK(0 , "reference", &option_reference, N_("repo"),
86                      N_("reference repository"), &opt_parse_reference),
87         OPT_STRING('o', "origin", &option_origin, N_("name"),
88                    N_("use <name> instead of 'origin' to track upstream")),
89         OPT_STRING('b', "branch", &option_branch, N_("branch"),
90                    N_("checkout <branch> instead of the remote's HEAD")),
91         OPT_STRING('u', "upload-pack", &option_upload_pack, N_("path"),
92                    N_("path to git-upload-pack on the remote")),
93         OPT_STRING(0, "depth", &option_depth, N_("depth"),
94                     N_("create a shallow clone of that depth")),
95         OPT_BOOL(0, "single-branch", &option_single_branch,
96                     N_("clone only one branch, HEAD or --branch")),
97         OPT_STRING(0, "separate-git-dir", &real_git_dir, N_("gitdir"),
98                    N_("separate git dir from working tree")),
99         OPT_STRING_LIST('c', "config", &option_config, N_("key=value"),
100                         N_("set config inside the new repository")),
101         OPT_END()
102 };
103
104 static const char *argv_submodule[] = {
105         "submodule", "update", "--init", "--recursive", NULL
106 };
107
108 static char *get_repo_path(const char *repo, int *is_bundle)
109 {
110         static char *suffix[] = { "/.git", "", ".git/.git", ".git" };
111         static char *bundle_suffix[] = { ".bundle", "" };
112         struct stat st;
113         int i;
114
115         for (i = 0; i < ARRAY_SIZE(suffix); i++) {
116                 const char *path;
117                 path = mkpath("%s%s", repo, suffix[i]);
118                 if (stat(path, &st))
119                         continue;
120                 if (S_ISDIR(st.st_mode) && is_git_directory(path)) {
121                         *is_bundle = 0;
122                         return xstrdup(absolute_path(path));
123                 } else if (S_ISREG(st.st_mode) && st.st_size > 8) {
124                         /* Is it a "gitfile"? */
125                         char signature[8];
126                         int len, fd = open(path, O_RDONLY);
127                         if (fd < 0)
128                                 continue;
129                         len = read_in_full(fd, signature, 8);
130                         close(fd);
131                         if (len != 8 || strncmp(signature, "gitdir: ", 8))
132                                 continue;
133                         path = read_gitfile(path);
134                         if (path) {
135                                 *is_bundle = 0;
136                                 return xstrdup(absolute_path(path));
137                         }
138                 }
139         }
140
141         for (i = 0; i < ARRAY_SIZE(bundle_suffix); i++) {
142                 const char *path;
143                 path = mkpath("%s%s", repo, bundle_suffix[i]);
144                 if (!stat(path, &st) && S_ISREG(st.st_mode)) {
145                         *is_bundle = 1;
146                         return xstrdup(absolute_path(path));
147                 }
148         }
149
150         return NULL;
151 }
152
153 static char *guess_dir_name(const char *repo, int is_bundle, int is_bare)
154 {
155         const char *end = repo + strlen(repo), *start;
156         char *dir;
157
158         /*
159          * Strip trailing spaces, slashes and /.git
160          */
161         while (repo < end && (is_dir_sep(end[-1]) || isspace(end[-1])))
162                 end--;
163         if (end - repo > 5 && is_dir_sep(end[-5]) &&
164             !strncmp(end - 4, ".git", 4)) {
165                 end -= 5;
166                 while (repo < end && is_dir_sep(end[-1]))
167                         end--;
168         }
169
170         /*
171          * Find last component, but be prepared that repo could have
172          * the form  "remote.example.com:foo.git", i.e. no slash
173          * in the directory part.
174          */
175         start = end;
176         while (repo < start && !is_dir_sep(start[-1]) && start[-1] != ':')
177                 start--;
178
179         /*
180          * Strip .{bundle,git}.
181          */
182         if (is_bundle) {
183                 if (end - start > 7 && !strncmp(end - 7, ".bundle", 7))
184                         end -= 7;
185         } else {
186                 if (end - start > 4 && !strncmp(end - 4, ".git", 4))
187                         end -= 4;
188         }
189
190         if (is_bare) {
191                 struct strbuf result = STRBUF_INIT;
192                 strbuf_addf(&result, "%.*s.git", (int)(end - start), start);
193                 dir = strbuf_detach(&result, NULL);
194         } else
195                 dir = xstrndup(start, end - start);
196         /*
197          * Replace sequences of 'control' characters and whitespace
198          * with one ascii space, remove leading and trailing spaces.
199          */
200         if (*dir) {
201                 char *out = dir;
202                 int prev_space = 1 /* strip leading whitespace */;
203                 for (end = dir; *end; ++end) {
204                         char ch = *end;
205                         if ((unsigned char)ch < '\x20')
206                                 ch = '\x20';
207                         if (isspace(ch)) {
208                                 if (prev_space)
209                                         continue;
210                                 prev_space = 1;
211                         } else
212                                 prev_space = 0;
213                         *out++ = ch;
214                 }
215                 *out = '\0';
216                 if (out > dir && prev_space)
217                         out[-1] = '\0';
218         }
219         return dir;
220 }
221
222 static void strip_trailing_slashes(char *dir)
223 {
224         char *end = dir + strlen(dir);
225
226         while (dir < end - 1 && is_dir_sep(end[-1]))
227                 end--;
228         *end = '\0';
229 }
230
231 static int add_one_reference(struct string_list_item *item, void *cb_data)
232 {
233         char *ref_git;
234         const char *repo;
235         struct strbuf alternate = STRBUF_INIT;
236
237         /* Beware: read_gitfile(), real_path() and mkpath() return static buffer */
238         ref_git = xstrdup(real_path(item->string));
239
240         repo = read_gitfile(ref_git);
241         if (!repo)
242                 repo = read_gitfile(mkpath("%s/.git", ref_git));
243         if (repo) {
244                 free(ref_git);
245                 ref_git = xstrdup(repo);
246         }
247
248         if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
249                 char *ref_git_git = mkpathdup("%s/.git", ref_git);
250                 free(ref_git);
251                 ref_git = ref_git_git;
252         } else if (!is_directory(mkpath("%s/objects", ref_git)))
253                 die(_("reference repository '%s' is not a local repository."),
254                     item->string);
255
256         strbuf_addf(&alternate, "%s/objects", ref_git);
257         add_to_alternates_file(alternate.buf);
258         strbuf_release(&alternate);
259         free(ref_git);
260         return 0;
261 }
262
263 static void setup_reference(void)
264 {
265         for_each_string_list(&option_reference, add_one_reference, NULL);
266 }
267
268 static void copy_alternates(struct strbuf *src, struct strbuf *dst,
269                             const char *src_repo)
270 {
271         /*
272          * Read from the source objects/info/alternates file
273          * and copy the entries to corresponding file in the
274          * destination repository with add_to_alternates_file().
275          * Both src and dst have "$path/objects/info/alternates".
276          *
277          * Instead of copying bit-for-bit from the original,
278          * we need to append to existing one so that the already
279          * created entry via "clone -s" is not lost, and also
280          * to turn entries with paths relative to the original
281          * absolute, so that they can be used in the new repository.
282          */
283         FILE *in = fopen(src->buf, "r");
284         struct strbuf line = STRBUF_INIT;
285
286         while (strbuf_getline(&line, in, '\n') != EOF) {
287                 char *abs_path, abs_buf[PATH_MAX];
288                 if (!line.len || line.buf[0] == '#')
289                         continue;
290                 if (is_absolute_path(line.buf)) {
291                         add_to_alternates_file(line.buf);
292                         continue;
293                 }
294                 abs_path = mkpath("%s/objects/%s", src_repo, line.buf);
295                 normalize_path_copy(abs_buf, abs_path);
296                 add_to_alternates_file(abs_buf);
297         }
298         strbuf_release(&line);
299         fclose(in);
300 }
301
302 static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest,
303                                    const char *src_repo, int src_baselen)
304 {
305         struct dirent *de;
306         struct stat buf;
307         int src_len, dest_len;
308         DIR *dir;
309
310         dir = opendir(src->buf);
311         if (!dir)
312                 die_errno(_("failed to open '%s'"), src->buf);
313
314         if (mkdir(dest->buf, 0777)) {
315                 if (errno != EEXIST)
316                         die_errno(_("failed to create directory '%s'"), dest->buf);
317                 else if (stat(dest->buf, &buf))
318                         die_errno(_("failed to stat '%s'"), dest->buf);
319                 else if (!S_ISDIR(buf.st_mode))
320                         die(_("%s exists and is not a directory"), dest->buf);
321         }
322
323         strbuf_addch(src, '/');
324         src_len = src->len;
325         strbuf_addch(dest, '/');
326         dest_len = dest->len;
327
328         while ((de = readdir(dir)) != NULL) {
329                 strbuf_setlen(src, src_len);
330                 strbuf_addstr(src, de->d_name);
331                 strbuf_setlen(dest, dest_len);
332                 strbuf_addstr(dest, de->d_name);
333                 if (stat(src->buf, &buf)) {
334                         warning (_("failed to stat %s\n"), src->buf);
335                         continue;
336                 }
337                 if (S_ISDIR(buf.st_mode)) {
338                         if (de->d_name[0] != '.')
339                                 copy_or_link_directory(src, dest,
340                                                        src_repo, src_baselen);
341                         continue;
342                 }
343
344                 /* Files that cannot be copied bit-for-bit... */
345                 if (!strcmp(src->buf + src_baselen, "/info/alternates")) {
346                         copy_alternates(src, dest, src_repo);
347                         continue;
348                 }
349
350                 if (unlink(dest->buf) && errno != ENOENT)
351                         die_errno(_("failed to unlink '%s'"), dest->buf);
352                 if (!option_no_hardlinks) {
353                         if (!link(src->buf, dest->buf))
354                                 continue;
355                         if (option_local > 0)
356                                 die_errno(_("failed to create link '%s'"), dest->buf);
357                         option_no_hardlinks = 1;
358                 }
359                 if (copy_file_with_time(dest->buf, src->buf, 0666))
360                         die_errno(_("failed to copy file to '%s'"), dest->buf);
361         }
362         closedir(dir);
363 }
364
365 static void clone_local(const char *src_repo, const char *dest_repo)
366 {
367         if (option_shared) {
368                 struct strbuf alt = STRBUF_INIT;
369                 strbuf_addf(&alt, "%s/objects", src_repo);
370                 add_to_alternates_file(alt.buf);
371                 strbuf_release(&alt);
372         } else {
373                 struct strbuf src = STRBUF_INIT;
374                 struct strbuf dest = STRBUF_INIT;
375                 strbuf_addf(&src, "%s/objects", src_repo);
376                 strbuf_addf(&dest, "%s/objects", dest_repo);
377                 copy_or_link_directory(&src, &dest, src_repo, src.len);
378                 strbuf_release(&src);
379                 strbuf_release(&dest);
380         }
381
382         if (0 <= option_verbosity)
383                 printf(_("done.\n"));
384 }
385
386 static const char *junk_work_tree;
387 static const char *junk_git_dir;
388 static pid_t junk_pid;
389 static enum {
390         JUNK_LEAVE_NONE,
391         JUNK_LEAVE_REPO,
392         JUNK_LEAVE_ALL
393 } junk_mode = JUNK_LEAVE_NONE;
394
395 static const char junk_leave_repo_msg[] =
396 N_("Clone succeeded, but checkout failed.\n"
397    "You can inspect what was checked out with 'git status'\n"
398    "and retry the checkout with 'git checkout -f HEAD'\n");
399
400 static void remove_junk(void)
401 {
402         struct strbuf sb = STRBUF_INIT;
403
404         switch (junk_mode) {
405         case JUNK_LEAVE_REPO:
406                 warning("%s", _(junk_leave_repo_msg));
407                 /* fall-through */
408         case JUNK_LEAVE_ALL:
409                 return;
410         default:
411                 /* proceed to removal */
412                 break;
413         }
414
415         if (getpid() != junk_pid)
416                 return;
417         if (junk_git_dir) {
418                 strbuf_addstr(&sb, junk_git_dir);
419                 remove_dir_recursively(&sb, 0);
420                 strbuf_reset(&sb);
421         }
422         if (junk_work_tree) {
423                 strbuf_addstr(&sb, junk_work_tree);
424                 remove_dir_recursively(&sb, 0);
425                 strbuf_reset(&sb);
426         }
427 }
428
429 static void remove_junk_on_signal(int signo)
430 {
431         remove_junk();
432         sigchain_pop(signo);
433         raise(signo);
434 }
435
436 static struct ref *find_remote_branch(const struct ref *refs, const char *branch)
437 {
438         struct ref *ref;
439         struct strbuf head = STRBUF_INIT;
440         strbuf_addstr(&head, "refs/heads/");
441         strbuf_addstr(&head, branch);
442         ref = find_ref_by_name(refs, head.buf);
443         strbuf_release(&head);
444
445         if (ref)
446                 return ref;
447
448         strbuf_addstr(&head, "refs/tags/");
449         strbuf_addstr(&head, branch);
450         ref = find_ref_by_name(refs, head.buf);
451         strbuf_release(&head);
452
453         return ref;
454 }
455
456 static struct ref *wanted_peer_refs(const struct ref *refs,
457                 struct refspec *refspec)
458 {
459         struct ref *head = copy_ref(find_ref_by_name(refs, "HEAD"));
460         struct ref *local_refs = head;
461         struct ref **tail = head ? &head->next : &local_refs;
462
463         if (option_single_branch) {
464                 struct ref *remote_head = NULL;
465
466                 if (!option_branch)
467                         remote_head = guess_remote_head(head, refs, 0);
468                 else {
469                         local_refs = NULL;
470                         tail = &local_refs;
471                         remote_head = copy_ref(find_remote_branch(refs, option_branch));
472                 }
473
474                 if (!remote_head && option_branch)
475                         warning(_("Could not find remote branch %s to clone."),
476                                 option_branch);
477                 else {
478                         get_fetch_map(remote_head, refspec, &tail, 0);
479
480                         /* if --branch=tag, pull the requested tag explicitly */
481                         get_fetch_map(remote_head, tag_refspec, &tail, 0);
482                 }
483         } else
484                 get_fetch_map(refs, refspec, &tail, 0);
485
486         if (!option_mirror && !option_single_branch)
487                 get_fetch_map(refs, tag_refspec, &tail, 0);
488
489         return local_refs;
490 }
491
492 static void write_remote_refs(const struct ref *local_refs)
493 {
494         const struct ref *r;
495
496         lock_packed_refs(LOCK_DIE_ON_ERROR);
497
498         for (r = local_refs; r; r = r->next) {
499                 if (!r->peer_ref)
500                         continue;
501                 add_packed_ref(r->peer_ref->name, r->old_sha1);
502         }
503
504         if (commit_packed_refs())
505                 die_errno("unable to overwrite old ref-pack file");
506 }
507
508 static void write_followtags(const struct ref *refs, const char *msg)
509 {
510         const struct ref *ref;
511         for (ref = refs; ref; ref = ref->next) {
512                 if (prefixcmp(ref->name, "refs/tags/"))
513                         continue;
514                 if (!suffixcmp(ref->name, "^{}"))
515                         continue;
516                 if (!has_sha1_file(ref->old_sha1))
517                         continue;
518                 update_ref(msg, ref->name, ref->old_sha1,
519                            NULL, 0, DIE_ON_ERR);
520         }
521 }
522
523 static int iterate_ref_map(void *cb_data, unsigned char sha1[20])
524 {
525         struct ref **rm = cb_data;
526         struct ref *ref = *rm;
527
528         /*
529          * Skip anything missing a peer_ref, which we are not
530          * actually going to write a ref for.
531          */
532         while (ref && !ref->peer_ref)
533                 ref = ref->next;
534         /* Returning -1 notes "end of list" to the caller. */
535         if (!ref)
536                 return -1;
537
538         hashcpy(sha1, ref->old_sha1);
539         *rm = ref->next;
540         return 0;
541 }
542
543 static void update_remote_refs(const struct ref *refs,
544                                const struct ref *mapped_refs,
545                                const struct ref *remote_head_points_at,
546                                const char *branch_top,
547                                const char *msg,
548                                struct transport *transport,
549                                int check_connectivity)
550 {
551         const struct ref *rm = mapped_refs;
552
553         if (check_connectivity) {
554                 if (0 <= option_verbosity)
555                         printf(_("Checking connectivity... "));
556                 if (check_everything_connected_with_transport(iterate_ref_map,
557                                                               0, &rm, transport))
558                         die(_("remote did not send all necessary objects"));
559                 if (0 <= option_verbosity)
560                         printf(_("done\n"));
561         }
562
563         if (refs) {
564                 write_remote_refs(mapped_refs);
565                 if (option_single_branch)
566                         write_followtags(refs, msg);
567         }
568
569         if (remote_head_points_at && !option_bare) {
570                 struct strbuf head_ref = STRBUF_INIT;
571                 strbuf_addstr(&head_ref, branch_top);
572                 strbuf_addstr(&head_ref, "HEAD");
573                 create_symref(head_ref.buf,
574                               remote_head_points_at->peer_ref->name,
575                               msg);
576         }
577 }
578
579 static void update_head(const struct ref *our, const struct ref *remote,
580                         const char *msg)
581 {
582         if (our && !prefixcmp(our->name, "refs/heads/")) {
583                 /* Local default branch link */
584                 create_symref("HEAD", our->name, NULL);
585                 if (!option_bare) {
586                         const char *head = skip_prefix(our->name, "refs/heads/");
587                         update_ref(msg, "HEAD", our->old_sha1, NULL, 0, DIE_ON_ERR);
588                         install_branch_config(0, head, option_origin, our->name);
589                 }
590         } else if (our) {
591                 struct commit *c = lookup_commit_reference(our->old_sha1);
592                 /* --branch specifies a non-branch (i.e. tags), detach HEAD */
593                 update_ref(msg, "HEAD", c->object.sha1,
594                            NULL, REF_NODEREF, DIE_ON_ERR);
595         } else if (remote) {
596                 /*
597                  * We know remote HEAD points to a non-branch, or
598                  * HEAD points to a branch but we don't know which one.
599                  * Detach HEAD in all these cases.
600                  */
601                 update_ref(msg, "HEAD", remote->old_sha1,
602                            NULL, REF_NODEREF, DIE_ON_ERR);
603         }
604 }
605
606 static int checkout(void)
607 {
608         unsigned char sha1[20];
609         char *head;
610         struct lock_file *lock_file;
611         struct unpack_trees_options opts;
612         struct tree *tree;
613         struct tree_desc t;
614         int err = 0, fd;
615
616         if (option_no_checkout)
617                 return 0;
618
619         head = resolve_refdup("HEAD", sha1, 1, NULL);
620         if (!head) {
621                 warning(_("remote HEAD refers to nonexistent ref, "
622                           "unable to checkout.\n"));
623                 return 0;
624         }
625         if (!strcmp(head, "HEAD")) {
626                 if (advice_detached_head)
627                         detach_advice(sha1_to_hex(sha1));
628         } else {
629                 if (prefixcmp(head, "refs/heads/"))
630                         die(_("HEAD not found below refs/heads!"));
631         }
632         free(head);
633
634         /* We need to be in the new work tree for the checkout */
635         setup_work_tree();
636
637         lock_file = xcalloc(1, sizeof(struct lock_file));
638         fd = hold_locked_index(lock_file, 1);
639
640         memset(&opts, 0, sizeof opts);
641         opts.update = 1;
642         opts.merge = 1;
643         opts.fn = oneway_merge;
644         opts.verbose_update = (option_verbosity >= 0);
645         opts.src_index = &the_index;
646         opts.dst_index = &the_index;
647
648         tree = parse_tree_indirect(sha1);
649         parse_tree(tree);
650         init_tree_desc(&t, tree->buffer, tree->size);
651         if (unpack_trees(1, &t, &opts) < 0)
652                 die(_("unable to checkout working tree"));
653
654         if (write_cache(fd, active_cache, active_nr) ||
655             commit_locked_index(lock_file))
656                 die(_("unable to write new index file"));
657
658         err |= run_hook(NULL, "post-checkout", sha1_to_hex(null_sha1),
659                         sha1_to_hex(sha1), "1", NULL);
660
661         if (!err && option_recursive)
662                 err = run_command_v_opt(argv_submodule, RUN_GIT_CMD);
663
664         return err;
665 }
666
667 static int write_one_config(const char *key, const char *value, void *data)
668 {
669         return git_config_set_multivar(key, value ? value : "true", "^$", 0);
670 }
671
672 static void write_config(struct string_list *config)
673 {
674         int i;
675
676         for (i = 0; i < config->nr; i++) {
677                 if (git_config_parse_parameter(config->items[i].string,
678                                                write_one_config, NULL) < 0)
679                         die("unable to write parameters to config file");
680         }
681 }
682
683 static void write_refspec_config(const char* src_ref_prefix,
684                 const struct ref* our_head_points_at,
685                 const struct ref* remote_head_points_at, struct strbuf* branch_top)
686 {
687         struct strbuf key = STRBUF_INIT;
688         struct strbuf value = STRBUF_INIT;
689
690         if (option_mirror || !option_bare) {
691                 if (option_single_branch && !option_mirror) {
692                         if (option_branch) {
693                                 if (strstr(our_head_points_at->name, "refs/tags/"))
694                                         strbuf_addf(&value, "+%s:%s", our_head_points_at->name,
695                                                 our_head_points_at->name);
696                                 else
697                                         strbuf_addf(&value, "+%s:%s%s", our_head_points_at->name,
698                                                 branch_top->buf, option_branch);
699                         } else if (remote_head_points_at) {
700                                 strbuf_addf(&value, "+%s:%s%s", remote_head_points_at->name,
701                                                 branch_top->buf,
702                                                 skip_prefix(remote_head_points_at->name, "refs/heads/"));
703                         }
704                         /*
705                          * otherwise, the next "git fetch" will
706                          * simply fetch from HEAD without updating
707                          * any remote-tracking branch, which is what
708                          * we want.
709                          */
710                 } else {
711                         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top->buf);
712                 }
713                 /* Configure the remote */
714                 if (value.len) {
715                         strbuf_addf(&key, "remote.%s.fetch", option_origin);
716                         git_config_set_multivar(key.buf, value.buf, "^$", 0);
717                         strbuf_reset(&key);
718
719                         if (option_mirror) {
720                                 strbuf_addf(&key, "remote.%s.mirror", option_origin);
721                                 git_config_set(key.buf, "true");
722                                 strbuf_reset(&key);
723                         }
724                 }
725         }
726
727         strbuf_release(&key);
728         strbuf_release(&value);
729 }
730
731 int cmd_clone(int argc, const char **argv, const char *prefix)
732 {
733         int is_bundle = 0, is_local;
734         struct stat buf;
735         const char *repo_name, *repo, *work_tree, *git_dir;
736         char *path, *dir;
737         int dest_exists;
738         const struct ref *refs, *remote_head;
739         const struct ref *remote_head_points_at;
740         const struct ref *our_head_points_at;
741         struct ref *mapped_refs;
742         const struct ref *ref;
743         struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
744         struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
745         struct transport *transport = NULL;
746         const char *src_ref_prefix = "refs/heads/";
747         struct remote *remote;
748         int err = 0, complete_refs_before_fetch = 1;
749
750         struct refspec *refspec;
751         const char *fetch_pattern;
752
753         junk_pid = getpid();
754
755         packet_trace_identity("clone");
756         argc = parse_options(argc, argv, prefix, builtin_clone_options,
757                              builtin_clone_usage, 0);
758
759         if (argc > 2)
760                 usage_msg_opt(_("Too many arguments."),
761                         builtin_clone_usage, builtin_clone_options);
762
763         if (argc == 0)
764                 usage_msg_opt(_("You must specify a repository to clone."),
765                         builtin_clone_usage, builtin_clone_options);
766
767         if (option_single_branch == -1)
768                 option_single_branch = option_depth ? 1 : 0;
769
770         if (option_mirror)
771                 option_bare = 1;
772
773         if (option_bare) {
774                 if (option_origin)
775                         die(_("--bare and --origin %s options are incompatible."),
776                             option_origin);
777                 if (real_git_dir)
778                         die(_("--bare and --separate-git-dir are incompatible."));
779                 option_no_checkout = 1;
780         }
781
782         if (!option_origin)
783                 option_origin = "origin";
784
785         repo_name = argv[0];
786
787         path = get_repo_path(repo_name, &is_bundle);
788         if (path)
789                 repo = xstrdup(absolute_path(repo_name));
790         else if (!strchr(repo_name, ':'))
791                 die(_("repository '%s' does not exist"), repo_name);
792         else
793                 repo = repo_name;
794         is_local = option_local != 0 && path && !is_bundle;
795         if (is_local && option_depth)
796                 warning(_("--depth is ignored in local clones; use file:// instead."));
797         if (option_local > 0 && !is_local)
798                 warning(_("--local is ignored"));
799
800         if (argc == 2)
801                 dir = xstrdup(argv[1]);
802         else
803                 dir = guess_dir_name(repo_name, is_bundle, option_bare);
804         strip_trailing_slashes(dir);
805
806         dest_exists = !stat(dir, &buf);
807         if (dest_exists && !is_empty_dir(dir))
808                 die(_("destination path '%s' already exists and is not "
809                         "an empty directory."), dir);
810
811         strbuf_addf(&reflog_msg, "clone: from %s", repo);
812
813         if (option_bare)
814                 work_tree = NULL;
815         else {
816                 work_tree = getenv("GIT_WORK_TREE");
817                 if (work_tree && !stat(work_tree, &buf))
818                         die(_("working tree '%s' already exists."), work_tree);
819         }
820
821         if (option_bare || work_tree)
822                 git_dir = xstrdup(dir);
823         else {
824                 work_tree = dir;
825                 git_dir = mkpathdup("%s/.git", dir);
826         }
827
828         if (!option_bare) {
829                 junk_work_tree = work_tree;
830                 if (safe_create_leading_directories_const(work_tree) < 0)
831                         die_errno(_("could not create leading directories of '%s'"),
832                                   work_tree);
833                 if (!dest_exists && mkdir(work_tree, 0777))
834                         die_errno(_("could not create work tree dir '%s'."),
835                                   work_tree);
836                 set_git_work_tree(work_tree);
837         }
838         junk_git_dir = git_dir;
839         atexit(remove_junk);
840         sigchain_push_common(remove_junk_on_signal);
841
842         if (safe_create_leading_directories_const(git_dir) < 0)
843                 die(_("could not create leading directories of '%s'"), git_dir);
844
845         set_git_dir_init(git_dir, real_git_dir, 0);
846         if (real_git_dir) {
847                 git_dir = real_git_dir;
848                 junk_git_dir = real_git_dir;
849         }
850
851         if (0 <= option_verbosity) {
852                 if (option_bare)
853                         printf(_("Cloning into bare repository '%s'...\n"), dir);
854                 else
855                         printf(_("Cloning into '%s'...\n"), dir);
856         }
857         init_db(option_template, INIT_DB_QUIET);
858         write_config(&option_config);
859
860         git_config(git_default_config, NULL);
861
862         if (option_bare) {
863                 if (option_mirror)
864                         src_ref_prefix = "refs/";
865                 strbuf_addstr(&branch_top, src_ref_prefix);
866
867                 git_config_set("core.bare", "true");
868         } else {
869                 strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
870         }
871
872         strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
873         strbuf_addf(&key, "remote.%s.url", option_origin);
874         git_config_set(key.buf, repo);
875         strbuf_reset(&key);
876
877         if (option_reference.nr)
878                 setup_reference();
879
880         fetch_pattern = value.buf;
881         refspec = parse_fetch_refspec(1, &fetch_pattern);
882
883         strbuf_reset(&value);
884
885         remote = remote_get(option_origin);
886         transport = transport_get(remote, remote->url[0]);
887
888         if (!is_local) {
889                 if (!transport->get_refs_list || !transport->fetch)
890                         die(_("Don't know how to clone %s"), transport->url);
891
892                 transport_set_option(transport, TRANS_OPT_KEEP, "yes");
893
894                 if (option_depth)
895                         transport_set_option(transport, TRANS_OPT_DEPTH,
896                                              option_depth);
897                 if (option_single_branch)
898                         transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
899
900                 transport_set_verbosity(transport, option_verbosity, option_progress);
901
902                 if (option_upload_pack)
903                         transport_set_option(transport, TRANS_OPT_UPLOADPACK,
904                                              option_upload_pack);
905
906                 if (transport->smart_options && !option_depth)
907                         transport->smart_options->check_self_contained_and_connected = 1;
908         }
909
910         refs = transport_get_remote_refs(transport);
911
912         if (refs) {
913                 mapped_refs = wanted_peer_refs(refs, refspec);
914                 /*
915                  * transport_get_remote_refs() may return refs with null sha-1
916                  * in mapped_refs (see struct transport->get_refs_list
917                  * comment). In that case we need fetch it early because
918                  * remote_head code below relies on it.
919                  *
920                  * for normal clones, transport_get_remote_refs() should
921                  * return reliable ref set, we can delay cloning until after
922                  * remote HEAD check.
923                  */
924                 for (ref = refs; ref; ref = ref->next)
925                         if (is_null_sha1(ref->old_sha1)) {
926                                 complete_refs_before_fetch = 0;
927                                 break;
928                         }
929
930                 if (!is_local && !complete_refs_before_fetch)
931                         transport_fetch_refs(transport, mapped_refs);
932
933                 remote_head = find_ref_by_name(refs, "HEAD");
934                 remote_head_points_at =
935                         guess_remote_head(remote_head, mapped_refs, 0);
936
937                 if (option_branch) {
938                         our_head_points_at =
939                                 find_remote_branch(mapped_refs, option_branch);
940
941                         if (!our_head_points_at)
942                                 die(_("Remote branch %s not found in upstream %s"),
943                                     option_branch, option_origin);
944                 }
945                 else
946                         our_head_points_at = remote_head_points_at;
947         }
948         else {
949                 warning(_("You appear to have cloned an empty repository."));
950                 mapped_refs = NULL;
951                 our_head_points_at = NULL;
952                 remote_head_points_at = NULL;
953                 remote_head = NULL;
954                 option_no_checkout = 1;
955                 if (!option_bare)
956                         install_branch_config(0, "master", option_origin,
957                                               "refs/heads/master");
958         }
959
960         write_refspec_config(src_ref_prefix, our_head_points_at,
961                         remote_head_points_at, &branch_top);
962
963         if (is_local)
964                 clone_local(path, git_dir);
965         else if (refs && complete_refs_before_fetch)
966                 transport_fetch_refs(transport, mapped_refs);
967
968         update_remote_refs(refs, mapped_refs, remote_head_points_at,
969                            branch_top.buf, reflog_msg.buf, transport, !is_local);
970
971         update_head(our_head_points_at, remote_head, reflog_msg.buf);
972
973         transport_unlock_pack(transport);
974         transport_disconnect(transport);
975
976         junk_mode = JUNK_LEAVE_REPO;
977         err = checkout();
978
979         strbuf_release(&reflog_msg);
980         strbuf_release(&branch_top);
981         strbuf_release(&key);
982         strbuf_release(&value);
983         junk_mode = JUNK_LEAVE_ALL;
984         return err;
985 }