1/*
2 * "git fetch"
3 */
4#include "cache.h"
5#include "refs.h"
6#include "commit.h"
7#include "builtin.h"
8#include "string-list.h"
9#include "remote.h"
10#include "transport.h"
11#include "run-command.h"
12#include "parse-options.h"
13#include "sigchain.h"
14
15static const char * const builtin_fetch_usage[] = {
16 "git fetch [options] [<repository> <refspec>...]",
17 NULL
18};
19
20enum {
21 TAGS_UNSET = 0,
22 TAGS_DEFAULT = 1,
23 TAGS_SET = 2
24};
25
26static int append, force, keep, update_head_ok, verbosity;
27static int tags = TAGS_DEFAULT;
28static const char *depth;
29static const char *upload_pack;
30static struct strbuf default_rla = STRBUF_INIT;
31static struct transport *transport;
32
33static struct option builtin_fetch_options[] = {
34 OPT__VERBOSITY(&verbosity),
35 OPT_BOOLEAN('a', "append", &append,
36 "append to .git/FETCH_HEAD instead of overwriting"),
37 OPT_STRING(0, "upload-pack", &upload_pack, "PATH",
38 "path to upload pack on remote end"),
39 OPT_BOOLEAN('f', "force", &force,
40 "force overwrite of local branch"),
41 OPT_SET_INT('t', "tags", &tags,
42 "fetch all tags and associated objects", TAGS_SET),
43 OPT_SET_INT('n', NULL, &tags,
44 "do not fetch all tags (--no-tags)", TAGS_UNSET),
45 OPT_BOOLEAN('k', "keep", &keep, "keep downloaded pack"),
46 OPT_BOOLEAN('u', "update-head-ok", &update_head_ok,
47 "allow updating of HEAD ref"),
48 OPT_STRING(0, "depth", &depth, "DEPTH",
49 "deepen history of shallow clone"),
50 OPT_END()
51};
52
53static void unlock_pack(void)
54{
55 if (transport)
56 transport_unlock_pack(transport);
57}
58
59static void unlock_pack_on_signal(int signo)
60{
61 unlock_pack();
62 sigchain_pop(signo);
63 raise(signo);
64}
65
66static void add_merge_config(struct ref **head,
67 const struct ref *remote_refs,
68 struct branch *branch,
69 struct ref ***tail)
70{
71 int i;
72
73 for (i = 0; i < branch->merge_nr; i++) {
74 struct ref *rm, **old_tail = *tail;
75 struct refspec refspec;
76
77 for (rm = *head; rm; rm = rm->next) {
78 if (branch_merge_matches(branch, i, rm->name)) {
79 rm->merge = 1;
80 break;
81 }
82 }
83 if (rm)
84 continue;
85
86 /*
87 * Not fetched to a tracking branch? We need to fetch
88 * it anyway to allow this branch's "branch.$name.merge"
89 * to be honored by 'git pull', but we do not have to
90 * fail if branch.$name.merge is misconfigured to point
91 * at a nonexisting branch. If we were indeed called by
92 * 'git pull', it will notice the misconfiguration because
93 * there is no entry in the resulting FETCH_HEAD marked
94 * for merging.
95 */
96 refspec.src = branch->merge[i]->src;
97 refspec.dst = NULL;
98 refspec.pattern = 0;
99 refspec.force = 0;
100 get_fetch_map(remote_refs, &refspec, tail, 1);
101 for (rm = *old_tail; rm; rm = rm->next)
102 rm->merge = 1;
103 }
104}
105
106static void find_non_local_tags(struct transport *transport,
107 struct ref **head,
108 struct ref ***tail);
109
110static struct ref *get_ref_map(struct transport *transport,
111 struct refspec *refs, int ref_count, int tags,
112 int *autotags)
113{
114 int i;
115 struct ref *rm;
116 struct ref *ref_map = NULL;
117 struct ref **tail = &ref_map;
118
119 const struct ref *remote_refs = transport_get_remote_refs(transport);
120
121 if (ref_count || tags == TAGS_SET) {
122 for (i = 0; i < ref_count; i++) {
123 get_fetch_map(remote_refs, &refs[i], &tail, 0);
124 if (refs[i].dst && refs[i].dst[0])
125 *autotags = 1;
126 }
127 /* Merge everything on the command line, but not --tags */
128 for (rm = ref_map; rm; rm = rm->next)
129 rm->merge = 1;
130 if (tags == TAGS_SET)
131 get_fetch_map(remote_refs, tag_refspec, &tail, 0);
132 } else {
133 /* Use the defaults */
134 struct remote *remote = transport->remote;
135 struct branch *branch = branch_get(NULL);
136 int has_merge = branch_has_merge_config(branch);
137 if (remote && (remote->fetch_refspec_nr || has_merge)) {
138 for (i = 0; i < remote->fetch_refspec_nr; i++) {
139 get_fetch_map(remote_refs, &remote->fetch[i], &tail, 0);
140 if (remote->fetch[i].dst &&
141 remote->fetch[i].dst[0])
142 *autotags = 1;
143 if (!i && !has_merge && ref_map &&
144 !remote->fetch[0].pattern)
145 ref_map->merge = 1;
146 }
147 /*
148 * if the remote we're fetching from is the same
149 * as given in branch.<name>.remote, we add the
150 * ref given in branch.<name>.merge, too.
151 */
152 if (has_merge &&
153 !strcmp(branch->remote_name, remote->name))
154 add_merge_config(&ref_map, remote_refs, branch, &tail);
155 } else {
156 ref_map = get_remote_ref(remote_refs, "HEAD");
157 if (!ref_map)
158 die("Couldn't find remote ref HEAD");
159 ref_map->merge = 1;
160 tail = &ref_map->next;
161 }
162 }
163 if (tags == TAGS_DEFAULT && *autotags)
164 find_non_local_tags(transport, &ref_map, &tail);
165 ref_remove_duplicates(ref_map);
166
167 return ref_map;
168}
169
170#define STORE_REF_ERROR_OTHER 1
171#define STORE_REF_ERROR_DF_CONFLICT 2
172
173static int s_update_ref(const char *action,
174 struct ref *ref,
175 int check_old)
176{
177 char msg[1024];
178 char *rla = getenv("GIT_REFLOG_ACTION");
179 static struct ref_lock *lock;
180
181 if (!rla)
182 rla = default_rla.buf;
183 snprintf(msg, sizeof(msg), "%s: %s", rla, action);
184 lock = lock_any_ref_for_update(ref->name,
185 check_old ? ref->old_sha1 : NULL, 0);
186 if (!lock)
187 return errno == ENOTDIR ? STORE_REF_ERROR_DF_CONFLICT :
188 STORE_REF_ERROR_OTHER;
189 if (write_ref_sha1(lock, ref->new_sha1, msg) < 0)
190 return errno == ENOTDIR ? STORE_REF_ERROR_DF_CONFLICT :
191 STORE_REF_ERROR_OTHER;
192 return 0;
193}
194
195#define SUMMARY_WIDTH (2 * DEFAULT_ABBREV + 3)
196#define REFCOL_WIDTH 10
197
198static int update_local_ref(struct ref *ref,
199 const char *remote,
200 char *display)
201{
202 struct commit *current = NULL, *updated;
203 enum object_type type;
204 struct branch *current_branch = branch_get(NULL);
205 const char *pretty_ref = prettify_refname(ref->name);
206
207 *display = 0;
208 type = sha1_object_info(ref->new_sha1, NULL);
209 if (type < 0)
210 die("object %s not found", sha1_to_hex(ref->new_sha1));
211
212 if (!hashcmp(ref->old_sha1, ref->new_sha1)) {
213 if (verbosity > 0)
214 sprintf(display, "= %-*s %-*s -> %s", SUMMARY_WIDTH,
215 "[up to date]", REFCOL_WIDTH, remote,
216 pretty_ref);
217 return 0;
218 }
219
220 if (current_branch &&
221 !strcmp(ref->name, current_branch->name) &&
222 !(update_head_ok || is_bare_repository()) &&
223 !is_null_sha1(ref->old_sha1)) {
224 /*
225 * If this is the head, and it's not okay to update
226 * the head, and the old value of the head isn't empty...
227 */
228 sprintf(display, "! %-*s %-*s -> %s (can't fetch in current branch)",
229 SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
230 pretty_ref);
231 return 1;
232 }
233
234 if (!is_null_sha1(ref->old_sha1) &&
235 !prefixcmp(ref->name, "refs/tags/")) {
236 int r;
237 r = s_update_ref("updating tag", ref, 0);
238 sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : '-',
239 SUMMARY_WIDTH, "[tag update]", REFCOL_WIDTH, remote,
240 pretty_ref, r ? " (unable to update local ref)" : "");
241 return r;
242 }
243
244 current = lookup_commit_reference_gently(ref->old_sha1, 1);
245 updated = lookup_commit_reference_gently(ref->new_sha1, 1);
246 if (!current || !updated) {
247 const char *msg;
248 const char *what;
249 int r;
250 if (!strncmp(ref->name, "refs/tags/", 10)) {
251 msg = "storing tag";
252 what = "[new tag]";
253 }
254 else {
255 msg = "storing head";
256 what = "[new branch]";
257 }
258
259 r = s_update_ref(msg, ref, 0);
260 sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : '*',
261 SUMMARY_WIDTH, what, REFCOL_WIDTH, remote, pretty_ref,
262 r ? " (unable to update local ref)" : "");
263 return r;
264 }
265
266 if (in_merge_bases(current, &updated, 1)) {
267 char quickref[83];
268 int r;
269 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
270 strcat(quickref, "..");
271 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
272 r = s_update_ref("fast forward", ref, 1);
273 sprintf(display, "%c %-*s %-*s -> %s%s", r ? '!' : ' ',
274 SUMMARY_WIDTH, quickref, REFCOL_WIDTH, remote,
275 pretty_ref, r ? " (unable to update local ref)" : "");
276 return r;
277 } else if (force || ref->force) {
278 char quickref[84];
279 int r;
280 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
281 strcat(quickref, "...");
282 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
283 r = s_update_ref("forced-update", ref, 1);
284 sprintf(display, "%c %-*s %-*s -> %s (%s)", r ? '!' : '+',
285 SUMMARY_WIDTH, quickref, REFCOL_WIDTH, remote,
286 pretty_ref,
287 r ? "unable to update local ref" : "forced update");
288 return r;
289 } else {
290 sprintf(display, "! %-*s %-*s -> %s (non fast forward)",
291 SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
292 pretty_ref);
293 return 1;
294 }
295}
296
297static int store_updated_refs(const char *raw_url, const char *remote_name,
298 struct ref *ref_map)
299{
300 FILE *fp;
301 struct commit *commit;
302 int url_len, i, note_len, shown_url = 0, rc = 0;
303 char note[1024];
304 const char *what, *kind;
305 struct ref *rm;
306 char *url, *filename = git_path("FETCH_HEAD");
307
308 fp = fopen(filename, "a");
309 if (!fp)
310 return error("cannot open %s: %s\n", filename, strerror(errno));
311
312 url = transport_anonymize_url(raw_url);
313 for (rm = ref_map; rm; rm = rm->next) {
314 struct ref *ref = NULL;
315
316 if (rm->peer_ref) {
317 ref = xcalloc(1, sizeof(*ref) + strlen(rm->peer_ref->name) + 1);
318 strcpy(ref->name, rm->peer_ref->name);
319 hashcpy(ref->old_sha1, rm->peer_ref->old_sha1);
320 hashcpy(ref->new_sha1, rm->old_sha1);
321 ref->force = rm->peer_ref->force;
322 }
323
324 commit = lookup_commit_reference_gently(rm->old_sha1, 1);
325 if (!commit)
326 rm->merge = 0;
327
328 if (!strcmp(rm->name, "HEAD")) {
329 kind = "";
330 what = "";
331 }
332 else if (!prefixcmp(rm->name, "refs/heads/")) {
333 kind = "branch";
334 what = rm->name + 11;
335 }
336 else if (!prefixcmp(rm->name, "refs/tags/")) {
337 kind = "tag";
338 what = rm->name + 10;
339 }
340 else if (!prefixcmp(rm->name, "refs/remotes/")) {
341 kind = "remote branch";
342 what = rm->name + 13;
343 }
344 else {
345 kind = "";
346 what = rm->name;
347 }
348
349 url_len = strlen(url);
350 for (i = url_len - 1; url[i] == '/' && 0 <= i; i--)
351 ;
352 url_len = i + 1;
353 if (4 < i && !strncmp(".git", url + i - 3, 4))
354 url_len = i - 3;
355
356 note_len = 0;
357 if (*what) {
358 if (*kind)
359 note_len += sprintf(note + note_len, "%s ",
360 kind);
361 note_len += sprintf(note + note_len, "'%s' of ", what);
362 }
363 note[note_len] = '\0';
364 fprintf(fp, "%s\t%s\t%s",
365 sha1_to_hex(commit ? commit->object.sha1 :
366 rm->old_sha1),
367 rm->merge ? "" : "not-for-merge",
368 note);
369 for (i = 0; i < url_len; ++i)
370 if ('\n' == url[i])
371 fputs("\\n", fp);
372 else
373 fputc(url[i], fp);
374 fputc('\n', fp);
375
376 if (ref)
377 rc |= update_local_ref(ref, what, note);
378 else
379 sprintf(note, "* %-*s %-*s -> FETCH_HEAD",
380 SUMMARY_WIDTH, *kind ? kind : "branch",
381 REFCOL_WIDTH, *what ? what : "HEAD");
382 if (*note) {
383 if (verbosity >= 0 && !shown_url) {
384 fprintf(stderr, "From %.*s\n",
385 url_len, url);
386 shown_url = 1;
387 }
388 if (verbosity >= 0)
389 fprintf(stderr, " %s\n", note);
390 }
391 }
392 free(url);
393 fclose(fp);
394 if (rc & STORE_REF_ERROR_DF_CONFLICT)
395 error("some local refs could not be updated; try running\n"
396 " 'git remote prune %s' to remove any old, conflicting "
397 "branches", remote_name);
398 return rc;
399}
400
401/*
402 * We would want to bypass the object transfer altogether if
403 * everything we are going to fetch already exists and is connected
404 * locally.
405 *
406 * The refs we are going to fetch are in ref_map. If running
407 *
408 * $ git rev-list --objects --stdin --not --all
409 *
410 * (feeding all the refs in ref_map on its standard input)
411 * does not error out, that means everything reachable from the
412 * refs we are going to fetch exists and is connected to some of
413 * our existing refs.
414 */
415static int quickfetch(struct ref *ref_map)
416{
417 struct child_process revlist;
418 struct ref *ref;
419 int err;
420 const char *argv[] = {"rev-list",
421 "--quiet", "--objects", "--stdin", "--not", "--all", NULL};
422
423 /*
424 * If we are deepening a shallow clone we already have these
425 * objects reachable. Running rev-list here will return with
426 * a good (0) exit status and we'll bypass the fetch that we
427 * really need to perform. Claiming failure now will ensure
428 * we perform the network exchange to deepen our history.
429 */
430 if (depth)
431 return -1;
432
433 if (!ref_map)
434 return 0;
435
436 memset(&revlist, 0, sizeof(revlist));
437 revlist.argv = argv;
438 revlist.git_cmd = 1;
439 revlist.no_stdout = 1;
440 revlist.no_stderr = 1;
441 revlist.in = -1;
442
443 err = start_command(&revlist);
444 if (err) {
445 error("could not run rev-list");
446 return err;
447 }
448
449 /*
450 * If rev-list --stdin encounters an unknown commit, it terminates,
451 * which will cause SIGPIPE in the write loop below.
452 */
453 sigchain_push(SIGPIPE, SIG_IGN);
454
455 for (ref = ref_map; ref; ref = ref->next) {
456 if (write_in_full(revlist.in, sha1_to_hex(ref->old_sha1), 40) < 0 ||
457 write_str_in_full(revlist.in, "\n") < 0) {
458 if (errno != EPIPE && errno != EINVAL)
459 error("failed write to rev-list: %s", strerror(errno));
460 err = -1;
461 break;
462 }
463 }
464
465 if (close(revlist.in)) {
466 error("failed to close rev-list's stdin: %s", strerror(errno));
467 err = -1;
468 }
469
470 sigchain_pop(SIGPIPE);
471
472 return finish_command(&revlist) || err;
473}
474
475static int fetch_refs(struct transport *transport, struct ref *ref_map)
476{
477 int ret = quickfetch(ref_map);
478 if (ret)
479 ret = transport_fetch_refs(transport, ref_map);
480 if (!ret)
481 ret |= store_updated_refs(transport->url,
482 transport->remote->name,
483 ref_map);
484 transport_unlock_pack(transport);
485 return ret;
486}
487
488static int add_existing(const char *refname, const unsigned char *sha1,
489 int flag, void *cbdata)
490{
491 struct string_list *list = (struct string_list *)cbdata;
492 string_list_insert(refname, list);
493 return 0;
494}
495
496static int will_fetch(struct ref **head, const unsigned char *sha1)
497{
498 struct ref *rm = *head;
499 while (rm) {
500 if (!hashcmp(rm->old_sha1, sha1))
501 return 1;
502 rm = rm->next;
503 }
504 return 0;
505}
506
507static void find_non_local_tags(struct transport *transport,
508 struct ref **head,
509 struct ref ***tail)
510{
511 struct string_list existing_refs = { NULL, 0, 0, 0 };
512 struct string_list new_refs = { NULL, 0, 0, 1 };
513 char *ref_name;
514 int ref_name_len;
515 const unsigned char *ref_sha1;
516 const struct ref *tag_ref;
517 struct ref *rm = NULL;
518 const struct ref *ref;
519
520 for_each_ref(add_existing, &existing_refs);
521 for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
522 if (prefixcmp(ref->name, "refs/tags"))
523 continue;
524
525 ref_name = xstrdup(ref->name);
526 ref_name_len = strlen(ref_name);
527 ref_sha1 = ref->old_sha1;
528
529 if (!strcmp(ref_name + ref_name_len - 3, "^{}")) {
530 ref_name[ref_name_len - 3] = 0;
531 tag_ref = transport_get_remote_refs(transport);
532 while (tag_ref) {
533 if (!strcmp(tag_ref->name, ref_name)) {
534 ref_sha1 = tag_ref->old_sha1;
535 break;
536 }
537 tag_ref = tag_ref->next;
538 }
539 }
540
541 if (!string_list_has_string(&existing_refs, ref_name) &&
542 !string_list_has_string(&new_refs, ref_name) &&
543 (has_sha1_file(ref->old_sha1) ||
544 will_fetch(head, ref->old_sha1))) {
545 string_list_insert(ref_name, &new_refs);
546
547 rm = alloc_ref(ref_name);
548 rm->peer_ref = alloc_ref(ref_name);
549 hashcpy(rm->old_sha1, ref_sha1);
550
551 **tail = rm;
552 *tail = &rm->next;
553 }
554 free(ref_name);
555 }
556 string_list_clear(&existing_refs, 0);
557 string_list_clear(&new_refs, 0);
558}
559
560static void check_not_current_branch(struct ref *ref_map)
561{
562 struct branch *current_branch = branch_get(NULL);
563
564 if (is_bare_repository() || !current_branch)
565 return;
566
567 for (; ref_map; ref_map = ref_map->next)
568 if (ref_map->peer_ref && !strcmp(current_branch->refname,
569 ref_map->peer_ref->name))
570 die("Refusing to fetch into current branch %s "
571 "of non-bare repository", current_branch->refname);
572}
573
574static int do_fetch(struct transport *transport,
575 struct refspec *refs, int ref_count)
576{
577 struct ref *ref_map;
578 struct ref *rm;
579 int autotags = (transport->remote->fetch_tags == 1);
580 if (transport->remote->fetch_tags == 2 && tags != TAGS_UNSET)
581 tags = TAGS_SET;
582 if (transport->remote->fetch_tags == -1)
583 tags = TAGS_UNSET;
584
585 if (!transport->get_refs_list || !transport->fetch)
586 die("Don't know how to fetch from %s", transport->url);
587
588 /* if not appending, truncate FETCH_HEAD */
589 if (!append) {
590 char *filename = git_path("FETCH_HEAD");
591 FILE *fp = fopen(filename, "w");
592 if (!fp)
593 return error("cannot open %s: %s\n", filename, strerror(errno));
594 fclose(fp);
595 }
596
597 ref_map = get_ref_map(transport, refs, ref_count, tags, &autotags);
598 if (!update_head_ok)
599 check_not_current_branch(ref_map);
600
601 for (rm = ref_map; rm; rm = rm->next) {
602 if (rm->peer_ref)
603 read_ref(rm->peer_ref->name, rm->peer_ref->old_sha1);
604 }
605
606 if (tags == TAGS_DEFAULT && autotags)
607 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
608 if (fetch_refs(transport, ref_map)) {
609 free_refs(ref_map);
610 return 1;
611 }
612 free_refs(ref_map);
613
614 /* if neither --no-tags nor --tags was specified, do automated tag
615 * following ... */
616 if (tags == TAGS_DEFAULT && autotags) {
617 struct ref **tail = &ref_map;
618 ref_map = NULL;
619 find_non_local_tags(transport, &ref_map, &tail);
620 if (ref_map) {
621 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, NULL);
622 transport_set_option(transport, TRANS_OPT_DEPTH, "0");
623 fetch_refs(transport, ref_map);
624 }
625 free_refs(ref_map);
626 }
627
628 return 0;
629}
630
631static void set_option(const char *name, const char *value)
632{
633 int r = transport_set_option(transport, name, value);
634 if (r < 0)
635 die("Option \"%s\" value \"%s\" is not valid for %s",
636 name, value, transport->url);
637 if (r > 0)
638 warning("Option \"%s\" is ignored for %s\n",
639 name, transport->url);
640}
641
642int cmd_fetch(int argc, const char **argv, const char *prefix)
643{
644 struct remote *remote;
645 int i;
646 static const char **refs = NULL;
647 int ref_nr = 0;
648 int exit_code;
649
650 /* Record the command line for the reflog */
651 strbuf_addstr(&default_rla, "fetch");
652 for (i = 1; i < argc; i++)
653 strbuf_addf(&default_rla, " %s", argv[i]);
654
655 argc = parse_options(argc, argv, prefix,
656 builtin_fetch_options, builtin_fetch_usage, 0);
657
658 if (argc == 0)
659 remote = remote_get(NULL);
660 else
661 remote = remote_get(argv[0]);
662
663 if (!remote)
664 die("Where do you want to fetch from today?");
665
666 transport = transport_get(remote, remote->url[0]);
667 if (verbosity >= 2)
668 transport->verbose = 1;
669 if (verbosity < 0)
670 transport->verbose = -1;
671 if (upload_pack)
672 set_option(TRANS_OPT_UPLOADPACK, upload_pack);
673 if (keep)
674 set_option(TRANS_OPT_KEEP, "yes");
675 if (depth)
676 set_option(TRANS_OPT_DEPTH, depth);
677
678 if (argc > 1) {
679 int j = 0;
680 refs = xcalloc(argc + 1, sizeof(const char *));
681 for (i = 1; i < argc; i++) {
682 if (!strcmp(argv[i], "tag")) {
683 char *ref;
684 i++;
685 if (i >= argc)
686 die("You need to specify a tag name.");
687 ref = xmalloc(strlen(argv[i]) * 2 + 22);
688 strcpy(ref, "refs/tags/");
689 strcat(ref, argv[i]);
690 strcat(ref, ":refs/tags/");
691 strcat(ref, argv[i]);
692 refs[j++] = ref;
693 } else
694 refs[j++] = argv[i];
695 }
696 refs[j] = NULL;
697 ref_nr = j;
698 }
699
700 sigchain_push_common(unlock_pack_on_signal);
701 atexit(unlock_pack);
702 exit_code = do_fetch(transport,
703 parse_fetch_refspec(ref_nr, refs), ref_nr);
704 transport_disconnect(transport);
705 transport = NULL;
706 return exit_code;
707}