fetch: support fetching from a shallow repository
[git] / builtin / fetch.c
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 #include "transport.h"
15 #include "submodule.h"
16 #include "connected.h"
17 #include "argv-array.h"
18
19 static const char * const builtin_fetch_usage[] = {
20         N_("git fetch [<options>] [<repository> [<refspec>...]]"),
21         N_("git fetch [<options>] <group>"),
22         N_("git fetch --multiple [<options>] [(<repository> | <group>)...]"),
23         N_("git fetch --all [<options>]"),
24         NULL
25 };
26
27 enum {
28         TAGS_UNSET = 0,
29         TAGS_DEFAULT = 1,
30         TAGS_SET = 2
31 };
32
33 static int fetch_prune_config = -1; /* unspecified */
34 static int prune = -1; /* unspecified */
35 #define PRUNE_BY_DEFAULT 0 /* do we prune by default? */
36
37 static int all, append, dry_run, force, keep, multiple, update_head_ok, verbosity;
38 static int progress = -1, recurse_submodules = RECURSE_SUBMODULES_DEFAULT;
39 static int tags = TAGS_DEFAULT, unshallow;
40 static const char *depth;
41 static const char *upload_pack;
42 static struct strbuf default_rla = STRBUF_INIT;
43 static struct transport *gtransport;
44 static struct transport *gsecondary;
45 static const char *submodule_prefix = "";
46 static const char *recurse_submodules_default;
47
48 static int option_parse_recurse_submodules(const struct option *opt,
49                                    const char *arg, int unset)
50 {
51         if (unset) {
52                 recurse_submodules = RECURSE_SUBMODULES_OFF;
53         } else {
54                 if (arg)
55                         recurse_submodules = parse_fetch_recurse_submodules_arg(opt->long_name, arg);
56                 else
57                         recurse_submodules = RECURSE_SUBMODULES_ON;
58         }
59         return 0;
60 }
61
62 static int git_fetch_config(const char *k, const char *v, void *cb)
63 {
64         if (!strcmp(k, "fetch.prune")) {
65                 fetch_prune_config = git_config_bool(k, v);
66                 return 0;
67         }
68         return 0;
69 }
70
71 static struct option builtin_fetch_options[] = {
72         OPT__VERBOSITY(&verbosity),
73         OPT_BOOL(0, "all", &all,
74                  N_("fetch from all remotes")),
75         OPT_BOOL('a', "append", &append,
76                  N_("append to .git/FETCH_HEAD instead of overwriting")),
77         OPT_STRING(0, "upload-pack", &upload_pack, N_("path"),
78                    N_("path to upload pack on remote end")),
79         OPT__FORCE(&force, N_("force overwrite of local branch")),
80         OPT_BOOL('m', "multiple", &multiple,
81                  N_("fetch from multiple remotes")),
82         OPT_SET_INT('t', "tags", &tags,
83                     N_("fetch all tags and associated objects"), TAGS_SET),
84         OPT_SET_INT('n', NULL, &tags,
85                     N_("do not fetch all tags (--no-tags)"), TAGS_UNSET),
86         OPT_BOOL('p', "prune", &prune,
87                  N_("prune remote-tracking branches no longer on remote")),
88         { OPTION_CALLBACK, 0, "recurse-submodules", NULL, N_("on-demand"),
89                     N_("control recursive fetching of submodules"),
90                     PARSE_OPT_OPTARG, option_parse_recurse_submodules },
91         OPT_BOOL(0, "dry-run", &dry_run,
92                  N_("dry run")),
93         OPT_BOOL('k', "keep", &keep, N_("keep downloaded pack")),
94         OPT_BOOL('u', "update-head-ok", &update_head_ok,
95                     N_("allow updating of HEAD ref")),
96         OPT_BOOL(0, "progress", &progress, N_("force progress reporting")),
97         OPT_STRING(0, "depth", &depth, N_("depth"),
98                    N_("deepen history of shallow clone")),
99         { OPTION_SET_INT, 0, "unshallow", &unshallow, NULL,
100                    N_("convert to a complete repository"),
101                    PARSE_OPT_NONEG | PARSE_OPT_NOARG, NULL, 1 },
102         { OPTION_STRING, 0, "submodule-prefix", &submodule_prefix, N_("dir"),
103                    N_("prepend this to submodule path output"), PARSE_OPT_HIDDEN },
104         { OPTION_STRING, 0, "recurse-submodules-default",
105                    &recurse_submodules_default, NULL,
106                    N_("default mode for recursion"), PARSE_OPT_HIDDEN },
107         OPT_END()
108 };
109
110 static void unlock_pack(void)
111 {
112         if (gtransport)
113                 transport_unlock_pack(gtransport);
114         if (gsecondary)
115                 transport_unlock_pack(gsecondary);
116 }
117
118 static void unlock_pack_on_signal(int signo)
119 {
120         unlock_pack();
121         sigchain_pop(signo);
122         raise(signo);
123 }
124
125 static void add_merge_config(struct ref **head,
126                            const struct ref *remote_refs,
127                            struct branch *branch,
128                            struct ref ***tail)
129 {
130         int i;
131
132         for (i = 0; i < branch->merge_nr; i++) {
133                 struct ref *rm, **old_tail = *tail;
134                 struct refspec refspec;
135
136                 for (rm = *head; rm; rm = rm->next) {
137                         if (branch_merge_matches(branch, i, rm->name)) {
138                                 rm->fetch_head_status = FETCH_HEAD_MERGE;
139                                 break;
140                         }
141                 }
142                 if (rm)
143                         continue;
144
145                 /*
146                  * Not fetched to a remote-tracking branch?  We need to fetch
147                  * it anyway to allow this branch's "branch.$name.merge"
148                  * to be honored by 'git pull', but we do not have to
149                  * fail if branch.$name.merge is misconfigured to point
150                  * at a nonexisting branch.  If we were indeed called by
151                  * 'git pull', it will notice the misconfiguration because
152                  * there is no entry in the resulting FETCH_HEAD marked
153                  * for merging.
154                  */
155                 memset(&refspec, 0, sizeof(refspec));
156                 refspec.src = branch->merge[i]->src;
157                 get_fetch_map(remote_refs, &refspec, tail, 1);
158                 for (rm = *old_tail; rm; rm = rm->next)
159                         rm->fetch_head_status = FETCH_HEAD_MERGE;
160         }
161 }
162
163 static void find_non_local_tags(struct transport *transport,
164                         struct ref **head,
165                         struct ref ***tail);
166
167 static struct ref *get_ref_map(struct transport *transport,
168                                struct refspec *refs, int ref_count, int tags,
169                                int *autotags)
170 {
171         int i;
172         struct ref *rm;
173         struct ref *ref_map = NULL;
174         struct ref **tail = &ref_map;
175
176         const struct ref *remote_refs = transport_get_remote_refs(transport);
177
178         if (ref_count || tags == TAGS_SET) {
179                 struct ref **old_tail;
180
181                 for (i = 0; i < ref_count; i++) {
182                         get_fetch_map(remote_refs, &refs[i], &tail, 0);
183                         if (refs[i].dst && refs[i].dst[0])
184                                 *autotags = 1;
185                 }
186                 /* Merge everything on the command line, but not --tags */
187                 for (rm = ref_map; rm; rm = rm->next)
188                         rm->fetch_head_status = FETCH_HEAD_MERGE;
189                 if (tags == TAGS_SET)
190                         get_fetch_map(remote_refs, tag_refspec, &tail, 0);
191
192                 /*
193                  * For any refs that we happen to be fetching via command-line
194                  * arguments, take the opportunity to update their configured
195                  * counterparts. However, we do not want to mention these
196                  * entries in FETCH_HEAD at all, as they would simply be
197                  * duplicates of existing entries.
198                  */
199                 old_tail = tail;
200                 for (i = 0; i < transport->remote->fetch_refspec_nr; i++)
201                         get_fetch_map(ref_map, &transport->remote->fetch[i],
202                                       &tail, 1);
203                 for (rm = *old_tail; rm; rm = rm->next)
204                         rm->fetch_head_status = FETCH_HEAD_IGNORE;
205         } else {
206                 /* Use the defaults */
207                 struct remote *remote = transport->remote;
208                 struct branch *branch = branch_get(NULL);
209                 int has_merge = branch_has_merge_config(branch);
210                 if (remote &&
211                     (remote->fetch_refspec_nr ||
212                      /* Note: has_merge implies non-NULL branch->remote_name */
213                      (has_merge && !strcmp(branch->remote_name, remote->name)))) {
214                         for (i = 0; i < remote->fetch_refspec_nr; i++) {
215                                 get_fetch_map(remote_refs, &remote->fetch[i], &tail, 0);
216                                 if (remote->fetch[i].dst &&
217                                     remote->fetch[i].dst[0])
218                                         *autotags = 1;
219                                 if (!i && !has_merge && ref_map &&
220                                     !remote->fetch[0].pattern)
221                                         ref_map->fetch_head_status = FETCH_HEAD_MERGE;
222                         }
223                         /*
224                          * if the remote we're fetching from is the same
225                          * as given in branch.<name>.remote, we add the
226                          * ref given in branch.<name>.merge, too.
227                          *
228                          * Note: has_merge implies non-NULL branch->remote_name
229                          */
230                         if (has_merge &&
231                             !strcmp(branch->remote_name, remote->name))
232                                 add_merge_config(&ref_map, remote_refs, branch, &tail);
233                 } else {
234                         ref_map = get_remote_ref(remote_refs, "HEAD");
235                         if (!ref_map)
236                                 die(_("Couldn't find remote ref HEAD"));
237                         ref_map->fetch_head_status = FETCH_HEAD_MERGE;
238                         tail = &ref_map->next;
239                 }
240         }
241         if (tags == TAGS_DEFAULT && *autotags)
242                 find_non_local_tags(transport, &ref_map, &tail);
243         ref_remove_duplicates(ref_map);
244
245         return ref_map;
246 }
247
248 #define STORE_REF_ERROR_OTHER 1
249 #define STORE_REF_ERROR_DF_CONFLICT 2
250
251 static int s_update_ref(const char *action,
252                         struct ref *ref,
253                         int check_old)
254 {
255         char msg[1024];
256         char *rla = getenv("GIT_REFLOG_ACTION");
257         static struct ref_lock *lock;
258
259         if (dry_run)
260                 return 0;
261         if (!rla)
262                 rla = default_rla.buf;
263         snprintf(msg, sizeof(msg), "%s: %s", rla, action);
264         lock = lock_any_ref_for_update(ref->name,
265                                        check_old ? ref->old_sha1 : NULL,
266                                        0, NULL);
267         if (!lock)
268                 return errno == ENOTDIR ? STORE_REF_ERROR_DF_CONFLICT :
269                                           STORE_REF_ERROR_OTHER;
270         if (write_ref_sha1(lock, ref->new_sha1, msg) < 0)
271                 return errno == ENOTDIR ? STORE_REF_ERROR_DF_CONFLICT :
272                                           STORE_REF_ERROR_OTHER;
273         return 0;
274 }
275
276 #define REFCOL_WIDTH  10
277
278 static int update_local_ref(struct ref *ref,
279                             const char *remote,
280                             const struct ref *remote_ref,
281                             struct strbuf *display)
282 {
283         struct commit *current = NULL, *updated;
284         enum object_type type;
285         struct branch *current_branch = branch_get(NULL);
286         const char *pretty_ref = prettify_refname(ref->name);
287
288         type = sha1_object_info(ref->new_sha1, NULL);
289         if (type < 0)
290                 die(_("object %s not found"), sha1_to_hex(ref->new_sha1));
291
292         if (!hashcmp(ref->old_sha1, ref->new_sha1)) {
293                 if (verbosity > 0)
294                         strbuf_addf(display, "= %-*s %-*s -> %s",
295                                     TRANSPORT_SUMMARY(_("[up to date]")),
296                                     REFCOL_WIDTH, remote, pretty_ref);
297                 return 0;
298         }
299
300         if (current_branch &&
301             !strcmp(ref->name, current_branch->name) &&
302             !(update_head_ok || is_bare_repository()) &&
303             !is_null_sha1(ref->old_sha1)) {
304                 /*
305                  * If this is the head, and it's not okay to update
306                  * the head, and the old value of the head isn't empty...
307                  */
308                 strbuf_addf(display,
309                             _("! %-*s %-*s -> %s  (can't fetch in current branch)"),
310                             TRANSPORT_SUMMARY(_("[rejected]")),
311                             REFCOL_WIDTH, remote, pretty_ref);
312                 return 1;
313         }
314
315         if (!is_null_sha1(ref->old_sha1) &&
316             !prefixcmp(ref->name, "refs/tags/")) {
317                 int r;
318                 r = s_update_ref("updating tag", ref, 0);
319                 strbuf_addf(display, "%c %-*s %-*s -> %s%s",
320                             r ? '!' : '-',
321                             TRANSPORT_SUMMARY(_("[tag update]")),
322                             REFCOL_WIDTH, remote, pretty_ref,
323                             r ? _("  (unable to update local ref)") : "");
324                 return r;
325         }
326
327         current = lookup_commit_reference_gently(ref->old_sha1, 1);
328         updated = lookup_commit_reference_gently(ref->new_sha1, 1);
329         if (!current || !updated) {
330                 const char *msg;
331                 const char *what;
332                 int r;
333                 /*
334                  * Nicely describe the new ref we're fetching.
335                  * Base this on the remote's ref name, as it's
336                  * more likely to follow a standard layout.
337                  */
338                 const char *name = remote_ref ? remote_ref->name : "";
339                 if (!prefixcmp(name, "refs/tags/")) {
340                         msg = "storing tag";
341                         what = _("[new tag]");
342                 } else if (!prefixcmp(name, "refs/heads/")) {
343                         msg = "storing head";
344                         what = _("[new branch]");
345                 } else {
346                         msg = "storing ref";
347                         what = _("[new ref]");
348                 }
349
350                 if ((recurse_submodules != RECURSE_SUBMODULES_OFF) &&
351                     (recurse_submodules != RECURSE_SUBMODULES_ON))
352                         check_for_new_submodule_commits(ref->new_sha1);
353                 r = s_update_ref(msg, ref, 0);
354                 strbuf_addf(display, "%c %-*s %-*s -> %s%s",
355                             r ? '!' : '*',
356                             TRANSPORT_SUMMARY(what),
357                             REFCOL_WIDTH, remote, pretty_ref,
358                             r ? _("  (unable to update local ref)") : "");
359                 return r;
360         }
361
362         if (in_merge_bases(current, updated)) {
363                 char quickref[83];
364                 int r;
365                 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
366                 strcat(quickref, "..");
367                 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
368                 if ((recurse_submodules != RECURSE_SUBMODULES_OFF) &&
369                     (recurse_submodules != RECURSE_SUBMODULES_ON))
370                         check_for_new_submodule_commits(ref->new_sha1);
371                 r = s_update_ref("fast-forward", ref, 1);
372                 strbuf_addf(display, "%c %-*s %-*s -> %s%s",
373                             r ? '!' : ' ',
374                             TRANSPORT_SUMMARY_WIDTH, quickref,
375                             REFCOL_WIDTH, remote, pretty_ref,
376                             r ? _("  (unable to update local ref)") : "");
377                 return r;
378         } else if (force || ref->force) {
379                 char quickref[84];
380                 int r;
381                 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
382                 strcat(quickref, "...");
383                 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
384                 if ((recurse_submodules != RECURSE_SUBMODULES_OFF) &&
385                     (recurse_submodules != RECURSE_SUBMODULES_ON))
386                         check_for_new_submodule_commits(ref->new_sha1);
387                 r = s_update_ref("forced-update", ref, 1);
388                 strbuf_addf(display, "%c %-*s %-*s -> %s  (%s)",
389                             r ? '!' : '+',
390                             TRANSPORT_SUMMARY_WIDTH, quickref,
391                             REFCOL_WIDTH, remote, pretty_ref,
392                             r ? _("unable to update local ref") : _("forced update"));
393                 return r;
394         } else {
395                 strbuf_addf(display, "! %-*s %-*s -> %s  %s",
396                             TRANSPORT_SUMMARY(_("[rejected]")),
397                             REFCOL_WIDTH, remote, pretty_ref,
398                             _("(non-fast-forward)"));
399                 return 1;
400         }
401 }
402
403 static int iterate_ref_map(void *cb_data, unsigned char sha1[20])
404 {
405         struct ref **rm = cb_data;
406         struct ref *ref = *rm;
407
408         while (ref && ref->status == REF_STATUS_REJECT_SHALLOW)
409                 ref = ref->next;
410         if (!ref)
411                 return -1; /* end of the list */
412         *rm = ref->next;
413         hashcpy(sha1, ref->old_sha1);
414         return 0;
415 }
416
417 static int store_updated_refs(const char *raw_url, const char *remote_name,
418                 struct ref *ref_map)
419 {
420         FILE *fp;
421         struct commit *commit;
422         int url_len, i, shown_url = 0, rc = 0;
423         struct strbuf note = STRBUF_INIT;
424         const char *what, *kind;
425         struct ref *rm;
426         char *url, *filename = dry_run ? "/dev/null" : git_path("FETCH_HEAD");
427         int want_status;
428
429         fp = fopen(filename, "a");
430         if (!fp)
431                 return error(_("cannot open %s: %s\n"), filename, strerror(errno));
432
433         if (raw_url)
434                 url = transport_anonymize_url(raw_url);
435         else
436                 url = xstrdup("foreign");
437
438         rm = ref_map;
439         if (check_everything_connected(iterate_ref_map, 0, &rm)) {
440                 rc = error(_("%s did not send all necessary objects\n"), url);
441                 goto abort;
442         }
443
444         /*
445          * We do a pass for each fetch_head_status type in their enum order, so
446          * merged entries are written before not-for-merge. That lets readers
447          * use FETCH_HEAD as a refname to refer to the ref to be merged.
448          */
449         for (want_status = FETCH_HEAD_MERGE;
450              want_status <= FETCH_HEAD_IGNORE;
451              want_status++) {
452                 for (rm = ref_map; rm; rm = rm->next) {
453                         struct ref *ref = NULL;
454                         const char *merge_status_marker = "";
455
456                         if (rm->status == REF_STATUS_REJECT_SHALLOW) {
457                                 if (want_status == FETCH_HEAD_MERGE)
458                                         warning(_("reject %s because shallow roots are not allowed to be updated"),
459                                                 rm->peer_ref ? rm->peer_ref->name : rm->name);
460                                 continue;
461                         }
462
463                         commit = lookup_commit_reference_gently(rm->old_sha1, 1);
464                         if (!commit)
465                                 rm->fetch_head_status = FETCH_HEAD_NOT_FOR_MERGE;
466
467                         if (rm->fetch_head_status != want_status)
468                                 continue;
469
470                         if (rm->peer_ref) {
471                                 ref = xcalloc(1, sizeof(*ref) + strlen(rm->peer_ref->name) + 1);
472                                 strcpy(ref->name, rm->peer_ref->name);
473                                 hashcpy(ref->old_sha1, rm->peer_ref->old_sha1);
474                                 hashcpy(ref->new_sha1, rm->old_sha1);
475                                 ref->force = rm->peer_ref->force;
476                         }
477
478
479                         if (!strcmp(rm->name, "HEAD")) {
480                                 kind = "";
481                                 what = "";
482                         }
483                         else if (!prefixcmp(rm->name, "refs/heads/")) {
484                                 kind = "branch";
485                                 what = rm->name + 11;
486                         }
487                         else if (!prefixcmp(rm->name, "refs/tags/")) {
488                                 kind = "tag";
489                                 what = rm->name + 10;
490                         }
491                         else if (!prefixcmp(rm->name, "refs/remotes/")) {
492                                 kind = "remote-tracking branch";
493                                 what = rm->name + 13;
494                         }
495                         else {
496                                 kind = "";
497                                 what = rm->name;
498                         }
499
500                         url_len = strlen(url);
501                         for (i = url_len - 1; url[i] == '/' && 0 <= i; i--)
502                                 ;
503                         url_len = i + 1;
504                         if (4 < i && !strncmp(".git", url + i - 3, 4))
505                                 url_len = i - 3;
506
507                         strbuf_reset(&note);
508                         if (*what) {
509                                 if (*kind)
510                                         strbuf_addf(&note, "%s ", kind);
511                                 strbuf_addf(&note, "'%s' of ", what);
512                         }
513                         switch (rm->fetch_head_status) {
514                         case FETCH_HEAD_NOT_FOR_MERGE:
515                                 merge_status_marker = "not-for-merge";
516                                 /* fall-through */
517                         case FETCH_HEAD_MERGE:
518                                 fprintf(fp, "%s\t%s\t%s",
519                                         sha1_to_hex(rm->old_sha1),
520                                         merge_status_marker,
521                                         note.buf);
522                                 for (i = 0; i < url_len; ++i)
523                                         if ('\n' == url[i])
524                                                 fputs("\\n", fp);
525                                         else
526                                                 fputc(url[i], fp);
527                                 fputc('\n', fp);
528                                 break;
529                         default:
530                                 /* do not write anything to FETCH_HEAD */
531                                 break;
532                         }
533
534                         strbuf_reset(&note);
535                         if (ref) {
536                                 rc |= update_local_ref(ref, what, rm, &note);
537                                 free(ref);
538                         } else
539                                 strbuf_addf(&note, "* %-*s %-*s -> FETCH_HEAD",
540                                             TRANSPORT_SUMMARY_WIDTH,
541                                             *kind ? kind : "branch",
542                                             REFCOL_WIDTH,
543                                             *what ? what : "HEAD");
544                         if (note.len) {
545                                 if (verbosity >= 0 && !shown_url) {
546                                         fprintf(stderr, _("From %.*s\n"),
547                                                         url_len, url);
548                                         shown_url = 1;
549                                 }
550                                 if (verbosity >= 0)
551                                         fprintf(stderr, " %s\n", note.buf);
552                         }
553                 }
554         }
555
556         if (rc & STORE_REF_ERROR_DF_CONFLICT)
557                 error(_("some local refs could not be updated; try running\n"
558                       " 'git remote prune %s' to remove any old, conflicting "
559                       "branches"), remote_name);
560
561  abort:
562         strbuf_release(&note);
563         free(url);
564         fclose(fp);
565         return rc;
566 }
567
568 /*
569  * We would want to bypass the object transfer altogether if
570  * everything we are going to fetch already exists and is connected
571  * locally.
572  */
573 static int quickfetch(struct ref *ref_map)
574 {
575         struct ref *rm = ref_map;
576
577         /*
578          * If we are deepening a shallow clone we already have these
579          * objects reachable.  Running rev-list here will return with
580          * a good (0) exit status and we'll bypass the fetch that we
581          * really need to perform.  Claiming failure now will ensure
582          * we perform the network exchange to deepen our history.
583          */
584         if (depth)
585                 return -1;
586         return check_everything_connected(iterate_ref_map, 1, &rm);
587 }
588
589 static int fetch_refs(struct transport *transport, struct ref *ref_map)
590 {
591         int ret = quickfetch(ref_map);
592         if (ret)
593                 ret = transport_fetch_refs(transport, ref_map);
594         if (!ret)
595                 ret |= store_updated_refs(transport->url,
596                                 transport->remote->name,
597                                 ref_map);
598         transport_unlock_pack(transport);
599         return ret;
600 }
601
602 static int prune_refs(struct refspec *refs, int ref_count, struct ref *ref_map)
603 {
604         int result = 0;
605         struct ref *ref, *stale_refs = get_stale_heads(refs, ref_count, ref_map);
606         const char *dangling_msg = dry_run
607                 ? _("   (%s will become dangling)")
608                 : _("   (%s has become dangling)");
609
610         for (ref = stale_refs; ref; ref = ref->next) {
611                 if (!dry_run)
612                         result |= delete_ref(ref->name, NULL, 0);
613                 if (verbosity >= 0) {
614                         fprintf(stderr, " x %-*s %-*s -> %s\n",
615                                 TRANSPORT_SUMMARY(_("[deleted]")),
616                                 REFCOL_WIDTH, _("(none)"), prettify_refname(ref->name));
617                         warn_dangling_symref(stderr, dangling_msg, ref->name);
618                 }
619         }
620         free_refs(stale_refs);
621         return result;
622 }
623
624 static int add_existing(const char *refname, const unsigned char *sha1,
625                         int flag, void *cbdata)
626 {
627         struct string_list *list = (struct string_list *)cbdata;
628         struct string_list_item *item = string_list_insert(list, refname);
629         item->util = xmalloc(20);
630         hashcpy(item->util, sha1);
631         return 0;
632 }
633
634 static int will_fetch(struct ref **head, const unsigned char *sha1)
635 {
636         struct ref *rm = *head;
637         while (rm) {
638                 if (!hashcmp(rm->old_sha1, sha1))
639                         return 1;
640                 rm = rm->next;
641         }
642         return 0;
643 }
644
645 static void find_non_local_tags(struct transport *transport,
646                         struct ref **head,
647                         struct ref ***tail)
648 {
649         struct string_list existing_refs = STRING_LIST_INIT_DUP;
650         struct string_list remote_refs = STRING_LIST_INIT_NODUP;
651         const struct ref *ref;
652         struct string_list_item *item = NULL;
653
654         for_each_ref(add_existing, &existing_refs);
655         for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
656                 if (prefixcmp(ref->name, "refs/tags/"))
657                         continue;
658
659                 /*
660                  * The peeled ref always follows the matching base
661                  * ref, so if we see a peeled ref that we don't want
662                  * to fetch then we can mark the ref entry in the list
663                  * as one to ignore by setting util to NULL.
664                  */
665                 if (!suffixcmp(ref->name, "^{}")) {
666                         if (item && !has_sha1_file(ref->old_sha1) &&
667                             !will_fetch(head, ref->old_sha1) &&
668                             !has_sha1_file(item->util) &&
669                             !will_fetch(head, item->util))
670                                 item->util = NULL;
671                         item = NULL;
672                         continue;
673                 }
674
675                 /*
676                  * If item is non-NULL here, then we previously saw a
677                  * ref not followed by a peeled reference, so we need
678                  * to check if it is a lightweight tag that we want to
679                  * fetch.
680                  */
681                 if (item && !has_sha1_file(item->util) &&
682                     !will_fetch(head, item->util))
683                         item->util = NULL;
684
685                 item = NULL;
686
687                 /* skip duplicates and refs that we already have */
688                 if (string_list_has_string(&remote_refs, ref->name) ||
689                     string_list_has_string(&existing_refs, ref->name))
690                         continue;
691
692                 item = string_list_insert(&remote_refs, ref->name);
693                 item->util = (void *)ref->old_sha1;
694         }
695         string_list_clear(&existing_refs, 1);
696
697         /*
698          * We may have a final lightweight tag that needs to be
699          * checked to see if it needs fetching.
700          */
701         if (item && !has_sha1_file(item->util) &&
702             !will_fetch(head, item->util))
703                 item->util = NULL;
704
705         /*
706          * For all the tags in the remote_refs string list,
707          * add them to the list of refs to be fetched
708          */
709         for_each_string_list_item(item, &remote_refs) {
710                 /* Unless we have already decided to ignore this item... */
711                 if (item->util)
712                 {
713                         struct ref *rm = alloc_ref(item->string);
714                         rm->peer_ref = alloc_ref(item->string);
715                         hashcpy(rm->old_sha1, item->util);
716                         **tail = rm;
717                         *tail = &rm->next;
718                 }
719         }
720
721         string_list_clear(&remote_refs, 0);
722 }
723
724 static void check_not_current_branch(struct ref *ref_map)
725 {
726         struct branch *current_branch = branch_get(NULL);
727
728         if (is_bare_repository() || !current_branch)
729                 return;
730
731         for (; ref_map; ref_map = ref_map->next)
732                 if (ref_map->peer_ref && !strcmp(current_branch->refname,
733                                         ref_map->peer_ref->name))
734                         die(_("Refusing to fetch into current branch %s "
735                             "of non-bare repository"), current_branch->refname);
736 }
737
738 static int truncate_fetch_head(void)
739 {
740         char *filename = git_path("FETCH_HEAD");
741         FILE *fp = fopen(filename, "w");
742
743         if (!fp)
744                 return error(_("cannot open %s: %s\n"), filename, strerror(errno));
745         fclose(fp);
746         return 0;
747 }
748
749 static void set_option(struct transport *transport, const char *name, const char *value)
750 {
751         int r = transport_set_option(transport, name, value);
752         if (r < 0)
753                 die(_("Option \"%s\" value \"%s\" is not valid for %s"),
754                     name, value, transport->url);
755         if (r > 0)
756                 warning(_("Option \"%s\" is ignored for %s\n"),
757                         name, transport->url);
758 }
759
760 static struct transport *prepare_transport(struct remote *remote)
761 {
762         struct transport *transport;
763         transport = transport_get(remote, NULL);
764         transport_set_verbosity(transport, verbosity, progress);
765         if (upload_pack)
766                 set_option(transport, TRANS_OPT_UPLOADPACK, upload_pack);
767         if (keep)
768                 set_option(transport, TRANS_OPT_KEEP, "yes");
769         if (depth)
770                 set_option(transport, TRANS_OPT_DEPTH, depth);
771         return transport;
772 }
773
774 static void backfill_tags(struct transport *transport, struct ref *ref_map)
775 {
776         if (transport->cannot_reuse) {
777                 gsecondary = prepare_transport(transport->remote);
778                 transport = gsecondary;
779         }
780
781         transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, NULL);
782         transport_set_option(transport, TRANS_OPT_DEPTH, "0");
783         fetch_refs(transport, ref_map);
784
785         if (gsecondary) {
786                 transport_disconnect(gsecondary);
787                 gsecondary = NULL;
788         }
789 }
790
791 static int do_fetch(struct transport *transport,
792                     struct refspec *refs, int ref_count)
793 {
794         struct string_list existing_refs = STRING_LIST_INIT_DUP;
795         struct ref *ref_map;
796         struct ref *rm;
797         int autotags = (transport->remote->fetch_tags == 1);
798         int retcode = 0;
799
800         for_each_ref(add_existing, &existing_refs);
801
802         if (tags == TAGS_DEFAULT) {
803                 if (transport->remote->fetch_tags == 2)
804                         tags = TAGS_SET;
805                 if (transport->remote->fetch_tags == -1)
806                         tags = TAGS_UNSET;
807         }
808
809         if (!transport->get_refs_list || !transport->fetch)
810                 die(_("Don't know how to fetch from %s"), transport->url);
811
812         /* if not appending, truncate FETCH_HEAD */
813         if (!append && !dry_run) {
814                 retcode = truncate_fetch_head();
815                 if (retcode)
816                         goto cleanup;
817         }
818
819         ref_map = get_ref_map(transport, refs, ref_count, tags, &autotags);
820         if (!update_head_ok)
821                 check_not_current_branch(ref_map);
822
823         for (rm = ref_map; rm; rm = rm->next) {
824                 if (rm->peer_ref) {
825                         struct string_list_item *peer_item =
826                                 string_list_lookup(&existing_refs,
827                                                    rm->peer_ref->name);
828                         if (peer_item)
829                                 hashcpy(rm->peer_ref->old_sha1,
830                                         peer_item->util);
831                 }
832         }
833
834         if (tags == TAGS_DEFAULT && autotags)
835                 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
836         if (fetch_refs(transport, ref_map)) {
837                 free_refs(ref_map);
838                 retcode = 1;
839                 goto cleanup;
840         }
841         if (prune) {
842                 /*
843                  * If --tags was specified, pretend that the user gave us
844                  * the canonical tags refspec
845                  */
846                 if (tags == TAGS_SET) {
847                         const char *tags_str = "refs/tags/*:refs/tags/*";
848                         struct refspec *tags_refspec, *refspec;
849
850                         /* Copy the refspec and add the tags to it */
851                         refspec = xcalloc(ref_count + 1, sizeof(struct refspec));
852                         tags_refspec = parse_fetch_refspec(1, &tags_str);
853                         memcpy(refspec, refs, ref_count * sizeof(struct refspec));
854                         memcpy(&refspec[ref_count], tags_refspec, sizeof(struct refspec));
855                         ref_count++;
856
857                         prune_refs(refspec, ref_count, ref_map);
858
859                         ref_count--;
860                         /* The rest of the strings belong to fetch_one */
861                         free_refspec(1, tags_refspec);
862                         free(refspec);
863                 } else if (ref_count) {
864                         prune_refs(refs, ref_count, ref_map);
865                 } else {
866                         prune_refs(transport->remote->fetch, transport->remote->fetch_refspec_nr, ref_map);
867                 }
868         }
869         free_refs(ref_map);
870
871         /* if neither --no-tags nor --tags was specified, do automated tag
872          * following ... */
873         if (tags == TAGS_DEFAULT && autotags) {
874                 struct ref **tail = &ref_map;
875                 ref_map = NULL;
876                 find_non_local_tags(transport, &ref_map, &tail);
877                 if (ref_map)
878                         backfill_tags(transport, ref_map);
879                 free_refs(ref_map);
880         }
881
882  cleanup:
883         string_list_clear(&existing_refs, 1);
884         return retcode;
885 }
886
887 static int get_one_remote_for_fetch(struct remote *remote, void *priv)
888 {
889         struct string_list *list = priv;
890         if (!remote->skip_default_update)
891                 string_list_append(list, remote->name);
892         return 0;
893 }
894
895 struct remote_group_data {
896         const char *name;
897         struct string_list *list;
898 };
899
900 static int get_remote_group(const char *key, const char *value, void *priv)
901 {
902         struct remote_group_data *g = priv;
903
904         if (!prefixcmp(key, "remotes.") &&
905                         !strcmp(key + 8, g->name)) {
906                 /* split list by white space */
907                 int space = strcspn(value, " \t\n");
908                 while (*value) {
909                         if (space > 1) {
910                                 string_list_append(g->list,
911                                                    xstrndup(value, space));
912                         }
913                         value += space + (value[space] != '\0');
914                         space = strcspn(value, " \t\n");
915                 }
916         }
917
918         return 0;
919 }
920
921 static int add_remote_or_group(const char *name, struct string_list *list)
922 {
923         int prev_nr = list->nr;
924         struct remote_group_data g;
925         g.name = name; g.list = list;
926
927         git_config(get_remote_group, &g);
928         if (list->nr == prev_nr) {
929                 struct remote *remote;
930                 if (!remote_is_configured(name))
931                         return 0;
932                 remote = remote_get(name);
933                 string_list_append(list, remote->name);
934         }
935         return 1;
936 }
937
938 static void add_options_to_argv(struct argv_array *argv)
939 {
940         if (dry_run)
941                 argv_array_push(argv, "--dry-run");
942         if (prune > 0)
943                 argv_array_push(argv, "--prune");
944         if (update_head_ok)
945                 argv_array_push(argv, "--update-head-ok");
946         if (force)
947                 argv_array_push(argv, "--force");
948         if (keep)
949                 argv_array_push(argv, "--keep");
950         if (recurse_submodules == RECURSE_SUBMODULES_ON)
951                 argv_array_push(argv, "--recurse-submodules");
952         else if (recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND)
953                 argv_array_push(argv, "--recurse-submodules=on-demand");
954         if (tags == TAGS_SET)
955                 argv_array_push(argv, "--tags");
956         else if (tags == TAGS_UNSET)
957                 argv_array_push(argv, "--no-tags");
958         if (verbosity >= 2)
959                 argv_array_push(argv, "-v");
960         if (verbosity >= 1)
961                 argv_array_push(argv, "-v");
962         else if (verbosity < 0)
963                 argv_array_push(argv, "-q");
964
965 }
966
967 static int fetch_multiple(struct string_list *list)
968 {
969         int i, result = 0;
970         struct argv_array argv = ARGV_ARRAY_INIT;
971
972         if (!append && !dry_run) {
973                 int errcode = truncate_fetch_head();
974                 if (errcode)
975                         return errcode;
976         }
977
978         argv_array_pushl(&argv, "fetch", "--append", NULL);
979         add_options_to_argv(&argv);
980
981         for (i = 0; i < list->nr; i++) {
982                 const char *name = list->items[i].string;
983                 argv_array_push(&argv, name);
984                 if (verbosity >= 0)
985                         printf(_("Fetching %s\n"), name);
986                 if (run_command_v_opt(argv.argv, RUN_GIT_CMD)) {
987                         error(_("Could not fetch %s"), name);
988                         result = 1;
989                 }
990                 argv_array_pop(&argv);
991         }
992
993         argv_array_clear(&argv);
994         return result;
995 }
996
997 static int fetch_one(struct remote *remote, int argc, const char **argv)
998 {
999         int i;
1000         static const char **refs = NULL;
1001         struct refspec *refspec;
1002         int ref_nr = 0;
1003         int exit_code;
1004
1005         if (!remote)
1006                 die(_("No remote repository specified.  Please, specify either a URL or a\n"
1007                     "remote name from which new revisions should be fetched."));
1008
1009         gtransport = prepare_transport(remote);
1010
1011         if (prune < 0) {
1012                 /* no command line request */
1013                 if (0 <= gtransport->remote->prune)
1014                         prune = gtransport->remote->prune;
1015                 else if (0 <= fetch_prune_config)
1016                         prune = fetch_prune_config;
1017                 else
1018                         prune = PRUNE_BY_DEFAULT;
1019         }
1020
1021         if (argc > 0) {
1022                 int j = 0;
1023                 refs = xcalloc(argc + 1, sizeof(const char *));
1024                 for (i = 0; i < argc; i++) {
1025                         if (!strcmp(argv[i], "tag")) {
1026                                 char *ref;
1027                                 i++;
1028                                 if (i >= argc)
1029                                         die(_("You need to specify a tag name."));
1030                                 ref = xmalloc(strlen(argv[i]) * 2 + 22);
1031                                 strcpy(ref, "refs/tags/");
1032                                 strcat(ref, argv[i]);
1033                                 strcat(ref, ":refs/tags/");
1034                                 strcat(ref, argv[i]);
1035                                 refs[j++] = ref;
1036                         } else
1037                                 refs[j++] = argv[i];
1038                 }
1039                 refs[j] = NULL;
1040                 ref_nr = j;
1041         }
1042
1043         sigchain_push_common(unlock_pack_on_signal);
1044         atexit(unlock_pack);
1045         refspec = parse_fetch_refspec(ref_nr, refs);
1046         exit_code = do_fetch(gtransport, refspec, ref_nr);
1047         free_refspec(ref_nr, refspec);
1048         transport_disconnect(gtransport);
1049         gtransport = NULL;
1050         return exit_code;
1051 }
1052
1053 int cmd_fetch(int argc, const char **argv, const char *prefix)
1054 {
1055         int i;
1056         struct string_list list = STRING_LIST_INIT_NODUP;
1057         struct remote *remote;
1058         int result = 0;
1059         static const char *argv_gc_auto[] = {
1060                 "gc", "--auto", NULL,
1061         };
1062
1063         packet_trace_identity("fetch");
1064
1065         /* Record the command line for the reflog */
1066         strbuf_addstr(&default_rla, "fetch");
1067         for (i = 1; i < argc; i++)
1068                 strbuf_addf(&default_rla, " %s", argv[i]);
1069
1070         git_config(git_fetch_config, NULL);
1071
1072         argc = parse_options(argc, argv, prefix,
1073                              builtin_fetch_options, builtin_fetch_usage, 0);
1074
1075         if (unshallow) {
1076                 if (depth)
1077                         die(_("--depth and --unshallow cannot be used together"));
1078                 else if (!is_repository_shallow())
1079                         die(_("--unshallow on a complete repository does not make sense"));
1080                 else {
1081                         static char inf_depth[12];
1082                         sprintf(inf_depth, "%d", INFINITE_DEPTH);
1083                         depth = inf_depth;
1084                 }
1085         }
1086
1087         if (recurse_submodules != RECURSE_SUBMODULES_OFF) {
1088                 if (recurse_submodules_default) {
1089                         int arg = parse_fetch_recurse_submodules_arg("--recurse-submodules-default", recurse_submodules_default);
1090                         set_config_fetch_recurse_submodules(arg);
1091                 }
1092                 gitmodules_config();
1093                 git_config(submodule_config, NULL);
1094         }
1095
1096         if (all) {
1097                 if (argc == 1)
1098                         die(_("fetch --all does not take a repository argument"));
1099                 else if (argc > 1)
1100                         die(_("fetch --all does not make sense with refspecs"));
1101                 (void) for_each_remote(get_one_remote_for_fetch, &list);
1102                 result = fetch_multiple(&list);
1103         } else if (argc == 0) {
1104                 /* No arguments -- use default remote */
1105                 remote = remote_get(NULL);
1106                 result = fetch_one(remote, argc, argv);
1107         } else if (multiple) {
1108                 /* All arguments are assumed to be remotes or groups */
1109                 for (i = 0; i < argc; i++)
1110                         if (!add_remote_or_group(argv[i], &list))
1111                                 die(_("No such remote or remote group: %s"), argv[i]);
1112                 result = fetch_multiple(&list);
1113         } else {
1114                 /* Single remote or group */
1115                 (void) add_remote_or_group(argv[0], &list);
1116                 if (list.nr > 1) {
1117                         /* More than one remote */
1118                         if (argc > 1)
1119                                 die(_("Fetching a group and specifying refspecs does not make sense"));
1120                         result = fetch_multiple(&list);
1121                 } else {
1122                         /* Zero or one remotes */
1123                         remote = remote_get(argv[0]);
1124                         result = fetch_one(remote, argc-1, argv+1);
1125                 }
1126         }
1127
1128         if (!result && (recurse_submodules != RECURSE_SUBMODULES_OFF)) {
1129                 struct argv_array options = ARGV_ARRAY_INIT;
1130
1131                 add_options_to_argv(&options);
1132                 result = fetch_populated_submodules(&options,
1133                                                     submodule_prefix,
1134                                                     recurse_submodules,
1135                                                     verbosity < 0);
1136                 argv_array_clear(&options);
1137         }
1138
1139         /* All names were strdup()ed or strndup()ed */
1140         list.strdup_strings = 1;
1141         string_list_clear(&list, 0);
1142
1143         run_command_v_opt(argv_gc_auto, RUN_GIT_CMD);
1144
1145         return result;
1146 }