refs: ref entry with NULL sha1 is can be a dangling symref
[git/mjg.git] / builtin-fetch.c
blob1f7a3f1ce66434a84ff96ef352245862fe088a70
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"
15 static const char * const builtin_fetch_usage[] = {
16 "git fetch [options] [<repository> <refspec>...]",
17 NULL
20 enum {
21 TAGS_UNSET = 0,
22 TAGS_DEFAULT = 1,
23 TAGS_SET = 2
26 static int append, force, keep, update_head_ok, verbosity;
27 static int tags = TAGS_DEFAULT;
28 static const char *depth;
29 static const char *upload_pack;
30 static struct strbuf default_rla = STRBUF_INIT;
31 static struct transport *transport;
33 static 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()
53 static void unlock_pack(void)
55 if (transport)
56 transport_unlock_pack(transport);
59 static void unlock_pack_on_signal(int signo)
61 unlock_pack();
62 sigchain_pop(signo);
63 raise(signo);
66 static void add_merge_config(struct ref **head,
67 const struct ref *remote_refs,
68 struct branch *branch,
69 struct ref ***tail)
71 int i;
73 for (i = 0; i < branch->merge_nr; i++) {
74 struct ref *rm, **old_tail = *tail;
75 struct refspec refspec;
77 for (rm = *head; rm; rm = rm->next) {
78 if (branch_merge_matches(branch, i, rm->name)) {
79 rm->merge = 1;
80 break;
83 if (rm)
84 continue;
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.
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;
106 static void find_non_local_tags(struct transport *transport,
107 struct ref **head,
108 struct ref ***tail);
110 static struct ref *get_ref_map(struct transport *transport,
111 struct refspec *refs, int ref_count, int tags,
112 int *autotags)
114 int i;
115 struct ref *rm;
116 struct ref *ref_map = NULL;
117 struct ref **tail = &ref_map;
119 const struct ref *remote_refs = transport_get_remote_refs(transport);
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;
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;
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.
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;
163 if (tags == TAGS_DEFAULT && *autotags)
164 find_non_local_tags(transport, &ref_map, &tail);
165 ref_remove_duplicates(ref_map);
167 return ref_map;
170 #define STORE_REF_ERROR_OTHER 1
171 #define STORE_REF_ERROR_DF_CONFLICT 2
173 static int s_update_ref(const char *action,
174 struct ref *ref,
175 int check_old)
177 char msg[1024];
178 char *rla = getenv("GIT_REFLOG_ACTION");
179 static struct ref_lock *lock;
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;
195 #define SUMMARY_WIDTH (2 * DEFAULT_ABBREV + 3)
196 #define REFCOL_WIDTH 10
198 static int update_local_ref(struct ref *ref,
199 const char *remote,
200 char *display)
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_ref(ref);
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));
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;
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)) {
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...
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;
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;
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]";
254 else {
255 msg = "storing head";
256 what = "[new branch]";
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;
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;
297 static int store_updated_refs(const char *url, const char *remote_name,
298 struct ref *ref_map)
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 *filename = git_path("FETCH_HEAD");
308 fp = fopen(filename, "a");
309 if (!fp)
310 return error("cannot open %s: %s\n", filename, strerror(errno));
311 for (rm = ref_map; rm; rm = rm->next) {
312 struct ref *ref = NULL;
314 if (rm->peer_ref) {
315 ref = xcalloc(1, sizeof(*ref) + strlen(rm->peer_ref->name) + 1);
316 strcpy(ref->name, rm->peer_ref->name);
317 hashcpy(ref->old_sha1, rm->peer_ref->old_sha1);
318 hashcpy(ref->new_sha1, rm->old_sha1);
319 ref->force = rm->peer_ref->force;
322 commit = lookup_commit_reference_gently(rm->old_sha1, 1);
323 if (!commit)
324 rm->merge = 0;
326 if (!strcmp(rm->name, "HEAD")) {
327 kind = "";
328 what = "";
330 else if (!prefixcmp(rm->name, "refs/heads/")) {
331 kind = "branch";
332 what = rm->name + 11;
334 else if (!prefixcmp(rm->name, "refs/tags/")) {
335 kind = "tag";
336 what = rm->name + 10;
338 else if (!prefixcmp(rm->name, "refs/remotes/")) {
339 kind = "remote branch";
340 what = rm->name + 13;
342 else {
343 kind = "";
344 what = rm->name;
347 url_len = strlen(url);
348 for (i = url_len - 1; url[i] == '/' && 0 <= i; i--)
350 url_len = i + 1;
351 if (4 < i && !strncmp(".git", url + i - 3, 4))
352 url_len = i - 3;
354 note_len = 0;
355 if (*what) {
356 if (*kind)
357 note_len += sprintf(note + note_len, "%s ",
358 kind);
359 note_len += sprintf(note + note_len, "'%s' of ", what);
361 note_len += sprintf(note + note_len, "%.*s", url_len, url);
362 fprintf(fp, "%s\t%s\t%s\n",
363 sha1_to_hex(commit ? commit->object.sha1 :
364 rm->old_sha1),
365 rm->merge ? "" : "not-for-merge",
366 note);
368 if (ref)
369 rc |= update_local_ref(ref, what, note);
370 else
371 sprintf(note, "* %-*s %-*s -> FETCH_HEAD",
372 SUMMARY_WIDTH, *kind ? kind : "branch",
373 REFCOL_WIDTH, *what ? what : "HEAD");
374 if (*note) {
375 if (verbosity >= 0 && !shown_url) {
376 fprintf(stderr, "From %.*s\n",
377 url_len, url);
378 shown_url = 1;
380 if (verbosity >= 0)
381 fprintf(stderr, " %s\n", note);
384 fclose(fp);
385 if (rc & STORE_REF_ERROR_DF_CONFLICT)
386 error("some local refs could not be updated; try running\n"
387 " 'git remote prune %s' to remove any old, conflicting "
388 "branches", remote_name);
389 return rc;
393 * We would want to bypass the object transfer altogether if
394 * everything we are going to fetch already exists and connected
395 * locally.
397 * The refs we are going to fetch are in to_fetch (nr_heads in
398 * total). If running
400 * $ git rev-list --objects to_fetch[0] to_fetch[1] ... --not --all
402 * does not error out, that means everything reachable from the
403 * refs we are going to fetch exists and is connected to some of
404 * our existing refs.
406 static int quickfetch(struct ref *ref_map)
408 struct child_process revlist;
409 struct ref *ref;
410 char **argv;
411 int i, err;
414 * If we are deepening a shallow clone we already have these
415 * objects reachable. Running rev-list here will return with
416 * a good (0) exit status and we'll bypass the fetch that we
417 * really need to perform. Claiming failure now will ensure
418 * we perform the network exchange to deepen our history.
420 if (depth)
421 return -1;
423 for (i = 0, ref = ref_map; ref; ref = ref->next)
424 i++;
425 if (!i)
426 return 0;
428 argv = xmalloc(sizeof(*argv) * (i + 6));
429 i = 0;
430 argv[i++] = xstrdup("rev-list");
431 argv[i++] = xstrdup("--quiet");
432 argv[i++] = xstrdup("--objects");
433 for (ref = ref_map; ref; ref = ref->next)
434 argv[i++] = xstrdup(sha1_to_hex(ref->old_sha1));
435 argv[i++] = xstrdup("--not");
436 argv[i++] = xstrdup("--all");
437 argv[i++] = NULL;
439 memset(&revlist, 0, sizeof(revlist));
440 revlist.argv = (const char**)argv;
441 revlist.git_cmd = 1;
442 revlist.no_stdin = 1;
443 revlist.no_stdout = 1;
444 revlist.no_stderr = 1;
445 err = run_command(&revlist);
447 for (i = 0; argv[i]; i++)
448 free(argv[i]);
449 free(argv);
450 return err;
453 static int fetch_refs(struct transport *transport, struct ref *ref_map)
455 int ret = quickfetch(ref_map);
456 if (ret)
457 ret = transport_fetch_refs(transport, ref_map);
458 if (!ret)
459 ret |= store_updated_refs(transport->url,
460 transport->remote->name,
461 ref_map);
462 transport_unlock_pack(transport);
463 return ret;
466 static int add_existing(const char *refname, const unsigned char *sha1,
467 int flag, void *cbdata)
469 struct string_list *list = (struct string_list *)cbdata;
470 string_list_insert(refname, list);
471 return 0;
474 static int will_fetch(struct ref **head, const unsigned char *sha1)
476 struct ref *rm = *head;
477 while (rm) {
478 if (!hashcmp(rm->old_sha1, sha1))
479 return 1;
480 rm = rm->next;
482 return 0;
485 static void find_non_local_tags(struct transport *transport,
486 struct ref **head,
487 struct ref ***tail)
489 struct string_list existing_refs = { NULL, 0, 0, 0 };
490 struct string_list new_refs = { NULL, 0, 0, 1 };
491 char *ref_name;
492 int ref_name_len;
493 const unsigned char *ref_sha1;
494 const struct ref *tag_ref;
495 struct ref *rm = NULL;
496 const struct ref *ref;
498 for_each_ref(add_existing, &existing_refs);
499 for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
500 if (prefixcmp(ref->name, "refs/tags"))
501 continue;
503 ref_name = xstrdup(ref->name);
504 ref_name_len = strlen(ref_name);
505 ref_sha1 = ref->old_sha1;
507 if (!strcmp(ref_name + ref_name_len - 3, "^{}")) {
508 ref_name[ref_name_len - 3] = 0;
509 tag_ref = transport_get_remote_refs(transport);
510 while (tag_ref) {
511 if (!strcmp(tag_ref->name, ref_name)) {
512 ref_sha1 = tag_ref->old_sha1;
513 break;
515 tag_ref = tag_ref->next;
519 if (!string_list_has_string(&existing_refs, ref_name) &&
520 !string_list_has_string(&new_refs, ref_name) &&
521 (has_sha1_file(ref->old_sha1) ||
522 will_fetch(head, ref->old_sha1))) {
523 string_list_insert(ref_name, &new_refs);
525 rm = alloc_ref(ref_name);
526 rm->peer_ref = alloc_ref(ref_name);
527 hashcpy(rm->old_sha1, ref_sha1);
529 **tail = rm;
530 *tail = &rm->next;
532 free(ref_name);
534 string_list_clear(&existing_refs, 0);
535 string_list_clear(&new_refs, 0);
538 static void check_not_current_branch(struct ref *ref_map)
540 struct branch *current_branch = branch_get(NULL);
542 if (is_bare_repository() || !current_branch)
543 return;
545 for (; ref_map; ref_map = ref_map->next)
546 if (ref_map->peer_ref && !strcmp(current_branch->refname,
547 ref_map->peer_ref->name))
548 die("Refusing to fetch into current branch %s "
549 "of non-bare repository", current_branch->refname);
552 static int do_fetch(struct transport *transport,
553 struct refspec *refs, int ref_count)
555 struct ref *ref_map;
556 struct ref *rm;
557 int autotags = (transport->remote->fetch_tags == 1);
558 if (transport->remote->fetch_tags == 2 && tags != TAGS_UNSET)
559 tags = TAGS_SET;
560 if (transport->remote->fetch_tags == -1)
561 tags = TAGS_UNSET;
563 if (!transport->get_refs_list || !transport->fetch)
564 die("Don't know how to fetch from %s", transport->url);
566 /* if not appending, truncate FETCH_HEAD */
567 if (!append) {
568 char *filename = git_path("FETCH_HEAD");
569 FILE *fp = fopen(filename, "w");
570 if (!fp)
571 return error("cannot open %s: %s\n", filename, strerror(errno));
572 fclose(fp);
575 ref_map = get_ref_map(transport, refs, ref_count, tags, &autotags);
576 if (!update_head_ok)
577 check_not_current_branch(ref_map);
579 for (rm = ref_map; rm; rm = rm->next) {
580 if (rm->peer_ref)
581 read_ref(rm->peer_ref->name, rm->peer_ref->old_sha1);
584 if (tags == TAGS_DEFAULT && autotags)
585 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
586 if (fetch_refs(transport, ref_map)) {
587 free_refs(ref_map);
588 return 1;
590 free_refs(ref_map);
592 /* if neither --no-tags nor --tags was specified, do automated tag
593 * following ... */
594 if (tags == TAGS_DEFAULT && autotags) {
595 struct ref **tail = &ref_map;
596 ref_map = NULL;
597 find_non_local_tags(transport, &ref_map, &tail);
598 if (ref_map) {
599 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, NULL);
600 transport_set_option(transport, TRANS_OPT_DEPTH, "0");
601 fetch_refs(transport, ref_map);
603 free_refs(ref_map);
606 return 0;
609 static void set_option(const char *name, const char *value)
611 int r = transport_set_option(transport, name, value);
612 if (r < 0)
613 die("Option \"%s\" value \"%s\" is not valid for %s",
614 name, value, transport->url);
615 if (r > 0)
616 warning("Option \"%s\" is ignored for %s\n",
617 name, transport->url);
620 int cmd_fetch(int argc, const char **argv, const char *prefix)
622 struct remote *remote;
623 int i;
624 static const char **refs = NULL;
625 int ref_nr = 0;
626 int exit_code;
628 /* Record the command line for the reflog */
629 strbuf_addstr(&default_rla, "fetch");
630 for (i = 1; i < argc; i++)
631 strbuf_addf(&default_rla, " %s", argv[i]);
633 argc = parse_options(argc, argv,
634 builtin_fetch_options, builtin_fetch_usage, 0);
636 if (argc == 0)
637 remote = remote_get(NULL);
638 else
639 remote = remote_get(argv[0]);
641 if (!remote)
642 die("Where do you want to fetch from today?");
644 transport = transport_get(remote, remote->url[0]);
645 if (verbosity >= 2)
646 transport->verbose = 1;
647 if (verbosity < 0)
648 transport->verbose = -1;
649 if (upload_pack)
650 set_option(TRANS_OPT_UPLOADPACK, upload_pack);
651 if (keep)
652 set_option(TRANS_OPT_KEEP, "yes");
653 if (depth)
654 set_option(TRANS_OPT_DEPTH, depth);
656 if (argc > 1) {
657 int j = 0;
658 refs = xcalloc(argc + 1, sizeof(const char *));
659 for (i = 1; i < argc; i++) {
660 if (!strcmp(argv[i], "tag")) {
661 char *ref;
662 i++;
663 if (i >= argc)
664 die("You need to specify a tag name.");
665 ref = xmalloc(strlen(argv[i]) * 2 + 22);
666 strcpy(ref, "refs/tags/");
667 strcat(ref, argv[i]);
668 strcat(ref, ":refs/tags/");
669 strcat(ref, argv[i]);
670 refs[j++] = ref;
671 } else
672 refs[j++] = argv[i];
674 refs[j] = NULL;
675 ref_nr = j;
678 sigchain_push_common(unlock_pack_on_signal);
679 atexit(unlock_pack);
680 exit_code = do_fetch(transport,
681 parse_fetch_refspec(ref_nr, refs), ref_nr);
682 transport_disconnect(transport);
683 transport = NULL;
684 return exit_code;