Allow cloning to an existing empty directory
[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 "cache.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 "pack-refs.h"
22
23 /*
24  * Overall FIXMEs:
25  *  - respect DB_ENVIRONMENT for .git/objects.
26  *
27  * Implementation notes:
28  *  - dropping use-separate-remote and no-separate-remote compatibility
29  *
30  */
31 static const char * const builtin_clone_usage[] = {
32         "git clone [options] [--] <repo> [<dir>]",
33         NULL
34 };
35
36 static int option_quiet, option_no_checkout, option_bare, option_mirror;
37 static int option_local, option_no_hardlinks, option_shared;
38 static char *option_template, *option_reference, *option_depth;
39 static char *option_origin = NULL;
40 static char *option_upload_pack = "git-upload-pack";
41 static int option_verbose;
42
43 static struct option builtin_clone_options[] = {
44         OPT__QUIET(&option_quiet),
45         OPT__VERBOSE(&option_verbose),
46         OPT_BOOLEAN('n', "no-checkout", &option_no_checkout,
47                     "don't create a checkout"),
48         OPT_BOOLEAN(0, "bare", &option_bare, "create a bare repository"),
49         OPT_BOOLEAN(0, "naked", &option_bare, "create a bare repository"),
50         OPT_BOOLEAN(0, "mirror", &option_mirror,
51                     "create a mirror repository (implies bare)"),
52         OPT_BOOLEAN('l', "local", &option_local,
53                     "to clone from a local repository"),
54         OPT_BOOLEAN(0, "no-hardlinks", &option_no_hardlinks,
55                     "don't use local hardlinks, always copy"),
56         OPT_BOOLEAN('s', "shared", &option_shared,
57                     "setup as shared repository"),
58         OPT_STRING(0, "template", &option_template, "path",
59                    "path the template repository"),
60         OPT_STRING(0, "reference", &option_reference, "repo",
61                    "reference repository"),
62         OPT_STRING('o', "origin", &option_origin, "branch",
63                    "use <branch> instead of 'origin' to track upstream"),
64         OPT_STRING('u', "upload-pack", &option_upload_pack, "path",
65                    "path to git-upload-pack on the remote"),
66         OPT_STRING(0, "depth", &option_depth, "depth",
67                     "create a shallow clone of that depth"),
68
69         OPT_END()
70 };
71
72 static char *get_repo_path(const char *repo, int *is_bundle)
73 {
74         static char *suffix[] = { "/.git", ".git", "" };
75         static char *bundle_suffix[] = { ".bundle", "" };
76         struct stat st;
77         int i;
78
79         for (i = 0; i < ARRAY_SIZE(suffix); i++) {
80                 const char *path;
81                 path = mkpath("%s%s", repo, suffix[i]);
82                 if (is_directory(path)) {
83                         *is_bundle = 0;
84                         return xstrdup(make_nonrelative_path(path));
85                 }
86         }
87
88         for (i = 0; i < ARRAY_SIZE(bundle_suffix); i++) {
89                 const char *path;
90                 path = mkpath("%s%s", repo, bundle_suffix[i]);
91                 if (!stat(path, &st) && S_ISREG(st.st_mode)) {
92                         *is_bundle = 1;
93                         return xstrdup(make_nonrelative_path(path));
94                 }
95         }
96
97         return NULL;
98 }
99
100 static char *guess_dir_name(const char *repo, int is_bundle, int is_bare)
101 {
102         const char *end = repo + strlen(repo), *start;
103
104         /*
105          * Strip trailing slashes and /.git
106          */
107         while (repo < end && is_dir_sep(end[-1]))
108                 end--;
109         if (end - repo > 5 && is_dir_sep(end[-5]) &&
110             !strncmp(end - 4, ".git", 4)) {
111                 end -= 5;
112                 while (repo < end && is_dir_sep(end[-1]))
113                         end--;
114         }
115
116         /*
117          * Find last component, but be prepared that repo could have
118          * the form  "remote.example.com:foo.git", i.e. no slash
119          * in the directory part.
120          */
121         start = end;
122         while (repo < start && !is_dir_sep(start[-1]) && start[-1] != ':')
123                 start--;
124
125         /*
126          * Strip .{bundle,git}.
127          */
128         if (is_bundle) {
129                 if (end - start > 7 && !strncmp(end - 7, ".bundle", 7))
130                         end -= 7;
131         } else {
132                 if (end - start > 4 && !strncmp(end - 4, ".git", 4))
133                         end -= 4;
134         }
135
136         if (is_bare) {
137                 struct strbuf result = STRBUF_INIT;
138                 strbuf_addf(&result, "%.*s.git", (int)(end - start), start);
139                 return strbuf_detach(&result, 0);
140         }
141
142         return xstrndup(start, end - start);
143 }
144
145 static void strip_trailing_slashes(char *dir)
146 {
147         char *end = dir + strlen(dir);
148
149         while (dir < end - 1 && is_dir_sep(end[-1]))
150                 end--;
151         *end = '\0';
152 }
153
154 static void setup_reference(const char *repo)
155 {
156         const char *ref_git;
157         char *ref_git_copy;
158
159         struct remote *remote;
160         struct transport *transport;
161         const struct ref *extra;
162
163         ref_git = make_absolute_path(option_reference);
164
165         if (is_directory(mkpath("%s/.git/objects", ref_git)))
166                 ref_git = mkpath("%s/.git", ref_git);
167         else if (!is_directory(mkpath("%s/objects", ref_git)))
168                 die("reference repository '%s' is not a local directory.",
169                     option_reference);
170
171         ref_git_copy = xstrdup(ref_git);
172
173         add_to_alternates_file(ref_git_copy);
174
175         remote = remote_get(ref_git_copy);
176         transport = transport_get(remote, ref_git_copy);
177         for (extra = transport_get_remote_refs(transport); extra;
178              extra = extra->next)
179                 add_extra_ref(extra->name, extra->old_sha1, 0);
180
181         transport_disconnect(transport);
182
183         free(ref_git_copy);
184 }
185
186 static void copy_or_link_directory(struct strbuf *src, struct strbuf *dest)
187 {
188         struct dirent *de;
189         struct stat buf;
190         int src_len, dest_len;
191         DIR *dir;
192
193         dir = opendir(src->buf);
194         if (!dir)
195                 die("failed to open %s", src->buf);
196
197         if (mkdir(dest->buf, 0777)) {
198                 if (errno != EEXIST)
199                         die("failed to create directory %s", dest->buf);
200                 else if (stat(dest->buf, &buf))
201                         die("failed to stat %s", dest->buf);
202                 else if (!S_ISDIR(buf.st_mode))
203                         die("%s exists and is not a directory", dest->buf);
204         }
205
206         strbuf_addch(src, '/');
207         src_len = src->len;
208         strbuf_addch(dest, '/');
209         dest_len = dest->len;
210
211         while ((de = readdir(dir)) != NULL) {
212                 strbuf_setlen(src, src_len);
213                 strbuf_addstr(src, de->d_name);
214                 strbuf_setlen(dest, dest_len);
215                 strbuf_addstr(dest, de->d_name);
216                 if (stat(src->buf, &buf)) {
217                         warning ("failed to stat %s\n", src->buf);
218                         continue;
219                 }
220                 if (S_ISDIR(buf.st_mode)) {
221                         if (de->d_name[0] != '.')
222                                 copy_or_link_directory(src, dest);
223                         continue;
224                 }
225
226                 if (unlink(dest->buf) && errno != ENOENT)
227                         die("failed to unlink %s", dest->buf);
228                 if (!option_no_hardlinks) {
229                         if (!link(src->buf, dest->buf))
230                                 continue;
231                         if (option_local)
232                                 die("failed to create link %s", dest->buf);
233                         option_no_hardlinks = 1;
234                 }
235                 if (copy_file(dest->buf, src->buf, 0666))
236                         die("failed to copy file to %s", dest->buf);
237         }
238         closedir(dir);
239 }
240
241 static const struct ref *clone_local(const char *src_repo,
242                                      const char *dest_repo)
243 {
244         const struct ref *ret;
245         struct strbuf src = STRBUF_INIT;
246         struct strbuf dest = STRBUF_INIT;
247         struct remote *remote;
248         struct transport *transport;
249
250         if (option_shared)
251                 add_to_alternates_file(src_repo);
252         else {
253                 strbuf_addf(&src, "%s/objects", src_repo);
254                 strbuf_addf(&dest, "%s/objects", dest_repo);
255                 copy_or_link_directory(&src, &dest);
256                 strbuf_release(&src);
257                 strbuf_release(&dest);
258         }
259
260         remote = remote_get(src_repo);
261         transport = transport_get(remote, src_repo);
262         ret = transport_get_remote_refs(transport);
263         transport_disconnect(transport);
264         return ret;
265 }
266
267 static const char *junk_work_tree;
268 static const char *junk_git_dir;
269 pid_t junk_pid;
270
271 static void remove_junk(void)
272 {
273         struct strbuf sb = STRBUF_INIT;
274         if (getpid() != junk_pid)
275                 return;
276         if (junk_git_dir) {
277                 strbuf_addstr(&sb, junk_git_dir);
278                 remove_dir_recursively(&sb, 0);
279                 strbuf_reset(&sb);
280         }
281         if (junk_work_tree) {
282                 strbuf_addstr(&sb, junk_work_tree);
283                 remove_dir_recursively(&sb, 0);
284                 strbuf_reset(&sb);
285         }
286 }
287
288 static void remove_junk_on_signal(int signo)
289 {
290         remove_junk();
291         signal(SIGINT, SIG_DFL);
292         raise(signo);
293 }
294
295 static const struct ref *locate_head(const struct ref *refs,
296                                      const struct ref *mapped_refs,
297                                      const struct ref **remote_head_p)
298 {
299         const struct ref *remote_head = NULL;
300         const struct ref *remote_master = NULL;
301         const struct ref *r;
302         for (r = refs; r; r = r->next)
303                 if (!strcmp(r->name, "HEAD"))
304                         remote_head = r;
305
306         for (r = mapped_refs; r; r = r->next)
307                 if (!strcmp(r->name, "refs/heads/master"))
308                         remote_master = r;
309
310         if (remote_head_p)
311                 *remote_head_p = remote_head;
312
313         /* If there's no HEAD value at all, never mind. */
314         if (!remote_head)
315                 return NULL;
316
317         /* If refs/heads/master could be right, it is. */
318         if (remote_master && !hashcmp(remote_master->old_sha1,
319                                       remote_head->old_sha1))
320                 return remote_master;
321
322         /* Look for another ref that points there */
323         for (r = mapped_refs; r; r = r->next)
324                 if (r != remote_head &&
325                     !hashcmp(r->old_sha1, remote_head->old_sha1))
326                         return r;
327
328         /* Nothing is the same */
329         return NULL;
330 }
331
332 static struct ref *write_remote_refs(const struct ref *refs,
333                 struct refspec *refspec, const char *reflog)
334 {
335         struct ref *local_refs = NULL;
336         struct ref **tail = &local_refs;
337         struct ref *r;
338
339         get_fetch_map(refs, refspec, &tail, 0);
340         if (!option_mirror)
341                 get_fetch_map(refs, tag_refspec, &tail, 0);
342
343         for (r = local_refs; r; r = r->next)
344                 add_extra_ref(r->peer_ref->name, r->old_sha1, 0);
345
346         pack_refs(PACK_REFS_ALL);
347         clear_extra_refs();
348
349         return local_refs;
350 }
351
352 int cmd_clone(int argc, const char **argv, const char *prefix)
353 {
354         int use_local_hardlinks = 1;
355         int use_separate_remote = 1;
356         int is_bundle = 0;
357         struct stat buf;
358         const char *repo_name, *repo, *work_tree, *git_dir;
359         char *path, *dir;
360         int dest_exists;
361         const struct ref *refs, *head_points_at, *remote_head, *mapped_refs;
362         struct strbuf key = STRBUF_INIT, value = STRBUF_INIT;
363         struct strbuf branch_top = STRBUF_INIT, reflog_msg = STRBUF_INIT;
364         struct transport *transport = NULL;
365         char *src_ref_prefix = "refs/heads/";
366
367         struct refspec refspec;
368
369         junk_pid = getpid();
370
371         argc = parse_options(argc, argv, builtin_clone_options,
372                              builtin_clone_usage, 0);
373
374         if (argc == 0)
375                 die("You must specify a repository to clone.");
376
377         if (option_no_hardlinks)
378                 use_local_hardlinks = 0;
379
380         if (option_mirror)
381                 option_bare = 1;
382
383         if (option_bare) {
384                 if (option_origin)
385                         die("--bare and --origin %s options are incompatible.",
386                             option_origin);
387                 option_no_checkout = 1;
388                 use_separate_remote = 0;
389         }
390
391         if (!option_origin)
392                 option_origin = "origin";
393
394         repo_name = argv[0];
395
396         path = get_repo_path(repo_name, &is_bundle);
397         if (path)
398                 repo = xstrdup(make_nonrelative_path(repo_name));
399         else if (!strchr(repo_name, ':'))
400                 repo = xstrdup(make_absolute_path(repo_name));
401         else
402                 repo = repo_name;
403
404         if (argc == 2)
405                 dir = xstrdup(argv[1]);
406         else
407                 dir = guess_dir_name(repo_name, is_bundle, option_bare);
408         strip_trailing_slashes(dir);
409
410         dest_exists = !stat(dir, &buf);
411         if (dest_exists && !is_empty_dir(dir))
412                 die("destination path '%s' already exists and is not "
413                         "an empty directory.", dir);
414
415         strbuf_addf(&reflog_msg, "clone: from %s", repo);
416
417         if (option_bare)
418                 work_tree = NULL;
419         else {
420                 work_tree = getenv("GIT_WORK_TREE");
421                 if (work_tree && !stat(work_tree, &buf))
422                         die("working tree '%s' already exists.", work_tree);
423         }
424
425         if (option_bare || work_tree)
426                 git_dir = xstrdup(dir);
427         else {
428                 work_tree = dir;
429                 git_dir = xstrdup(mkpath("%s/.git", dir));
430         }
431
432         if (!option_bare) {
433                 junk_work_tree = work_tree;
434                 if (safe_create_leading_directories_const(work_tree) < 0)
435                         die("could not create leading directories of '%s': %s",
436                                         work_tree, strerror(errno));
437                 if (!dest_exists && mkdir(work_tree, 0755))
438                         die("could not create work tree dir '%s': %s.",
439                                         work_tree, strerror(errno));
440                 set_git_work_tree(work_tree);
441         }
442         junk_git_dir = git_dir;
443         atexit(remove_junk);
444         signal(SIGINT, remove_junk_on_signal);
445
446         setenv(CONFIG_ENVIRONMENT, xstrdup(mkpath("%s/config", git_dir)), 1);
447
448         if (safe_create_leading_directories_const(git_dir) < 0)
449                 die("could not create leading directories of '%s'", git_dir);
450         set_git_dir(make_absolute_path(git_dir));
451
452         init_db(option_template, option_quiet ? INIT_DB_QUIET : 0);
453
454         /*
455          * At this point, the config exists, so we do not need the
456          * environment variable.  We actually need to unset it, too, to
457          * re-enable parsing of the global configs.
458          */
459         unsetenv(CONFIG_ENVIRONMENT);
460
461         if (option_reference)
462                 setup_reference(git_dir);
463
464         git_config(git_default_config, NULL);
465
466         if (option_bare) {
467                 if (option_mirror)
468                         src_ref_prefix = "refs/";
469                 strbuf_addstr(&branch_top, src_ref_prefix);
470
471                 git_config_set("core.bare", "true");
472         } else {
473                 strbuf_addf(&branch_top, "refs/remotes/%s/", option_origin);
474         }
475
476         if (option_mirror || !option_bare) {
477                 /* Configure the remote */
478                 if (option_mirror) {
479                         strbuf_addf(&key, "remote.%s.mirror", option_origin);
480                         git_config_set(key.buf, "true");
481                         strbuf_reset(&key);
482                 }
483
484                 strbuf_addf(&key, "remote.%s.url", option_origin);
485                 git_config_set(key.buf, repo);
486                         strbuf_reset(&key);
487
488                 strbuf_addf(&key, "remote.%s.fetch", option_origin);
489                 strbuf_addf(&value, "+%s*:%s*", src_ref_prefix, branch_top.buf);
490                 git_config_set_multivar(key.buf, value.buf, "^$", 0);
491                 strbuf_reset(&key);
492                 strbuf_reset(&value);
493         }
494
495         refspec.force = 0;
496         refspec.pattern = 1;
497         refspec.src = src_ref_prefix;
498         refspec.dst = branch_top.buf;
499
500         if (path && !is_bundle)
501                 refs = clone_local(path, git_dir);
502         else {
503                 struct remote *remote = remote_get(argv[0]);
504                 transport = transport_get(remote, remote->url[0]);
505
506                 if (!transport->get_refs_list || !transport->fetch)
507                         die("Don't know how to clone %s", transport->url);
508
509                 transport_set_option(transport, TRANS_OPT_KEEP, "yes");
510
511                 if (option_depth)
512                         transport_set_option(transport, TRANS_OPT_DEPTH,
513                                              option_depth);
514
515                 if (option_quiet)
516                         transport->verbose = -1;
517                 else if (option_verbose)
518                         transport->progress = 1;
519
520                 if (option_upload_pack)
521                         transport_set_option(transport, TRANS_OPT_UPLOADPACK,
522                                              option_upload_pack);
523
524                 refs = transport_get_remote_refs(transport);
525                 transport_fetch_refs(transport, refs);
526         }
527
528         clear_extra_refs();
529
530         mapped_refs = write_remote_refs(refs, &refspec, reflog_msg.buf);
531
532         head_points_at = locate_head(refs, mapped_refs, &remote_head);
533
534         if (head_points_at) {
535                 /* Local default branch link */
536                 create_symref("HEAD", head_points_at->name, NULL);
537
538                 if (!option_bare) {
539                         struct strbuf head_ref = STRBUF_INIT;
540                         const char *head = head_points_at->name;
541
542                         if (!prefixcmp(head, "refs/heads/"))
543                                 head += 11;
544
545                         /* Set up the initial local branch */
546
547                         /* Local branch initial value */
548                         update_ref(reflog_msg.buf, "HEAD",
549                                    head_points_at->old_sha1,
550                                    NULL, 0, DIE_ON_ERR);
551
552                         strbuf_addstr(&head_ref, branch_top.buf);
553                         strbuf_addstr(&head_ref, "HEAD");
554
555                         /* Remote branch link */
556                         create_symref(head_ref.buf,
557                                       head_points_at->peer_ref->name,
558                                       reflog_msg.buf);
559
560                         strbuf_addf(&key, "branch.%s.remote", head);
561                         git_config_set(key.buf, option_origin);
562                         strbuf_reset(&key);
563                         strbuf_addf(&key, "branch.%s.merge", head);
564                         git_config_set(key.buf, head_points_at->name);
565                 }
566         } else if (remote_head) {
567                 /* Source had detached HEAD pointing somewhere. */
568                 if (!option_bare)
569                         update_ref(reflog_msg.buf, "HEAD",
570                                    remote_head->old_sha1,
571                                    NULL, REF_NODEREF, DIE_ON_ERR);
572         } else {
573                 /* Nothing to checkout out */
574                 if (!option_no_checkout)
575                         warning("remote HEAD refers to nonexistent ref, "
576                                 "unable to checkout.\n");
577                 option_no_checkout = 1;
578         }
579
580         if (transport)
581                 transport_unlock_pack(transport);
582
583         if (!option_no_checkout) {
584                 struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
585                 struct unpack_trees_options opts;
586                 struct tree *tree;
587                 struct tree_desc t;
588                 int fd;
589
590                 /* We need to be in the new work tree for the checkout */
591                 setup_work_tree();
592
593                 fd = hold_locked_index(lock_file, 1);
594
595                 memset(&opts, 0, sizeof opts);
596                 opts.update = 1;
597                 opts.merge = 1;
598                 opts.fn = oneway_merge;
599                 opts.verbose_update = !option_quiet;
600                 opts.src_index = &the_index;
601                 opts.dst_index = &the_index;
602
603                 tree = parse_tree_indirect(remote_head->old_sha1);
604                 parse_tree(tree);
605                 init_tree_desc(&t, tree->buffer, tree->size);
606                 unpack_trees(1, &t, &opts);
607
608                 if (write_cache(fd, active_cache, active_nr) ||
609                     commit_locked_index(lock_file))
610                         die("unable to write new index file");
611         }
612
613         strbuf_release(&reflog_msg);
614         strbuf_release(&branch_top);
615         strbuf_release(&key);
616         strbuf_release(&value);
617         junk_pid = 0;
618         return 0;
619 }