fetch: do not redundantly calculate tag refmap
[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 "submodule-config.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, update_shallow;
40 static int max_children = 1;
41 static enum transport_family family;
42 static const char *depth;
43 static const char *upload_pack;
44 static struct strbuf default_rla = STRBUF_INIT;
45 static struct transport *gtransport;
46 static struct transport *gsecondary;
47 static const char *submodule_prefix = "";
48 static const char *recurse_submodules_default;
49 static int shown_url = 0;
50 static int refmap_alloc, refmap_nr;
51 static const char **refmap_array;
52
53 static int option_parse_recurse_submodules(const struct option *opt,
54                                    const char *arg, int unset)
55 {
56         if (unset) {
57                 recurse_submodules = RECURSE_SUBMODULES_OFF;
58         } else {
59                 if (arg)
60                         recurse_submodules = parse_fetch_recurse_submodules_arg(opt->long_name, arg);
61                 else
62                         recurse_submodules = RECURSE_SUBMODULES_ON;
63         }
64         return 0;
65 }
66
67 static int git_fetch_config(const char *k, const char *v, void *cb)
68 {
69         if (!strcmp(k, "fetch.prune")) {
70                 fetch_prune_config = git_config_bool(k, v);
71                 return 0;
72         }
73         return git_default_config(k, v, cb);
74 }
75
76 static int parse_refmap_arg(const struct option *opt, const char *arg, int unset)
77 {
78         ALLOC_GROW(refmap_array, refmap_nr + 1, refmap_alloc);
79
80         /*
81          * "git fetch --refmap='' origin foo"
82          * can be used to tell the command not to store anywhere
83          */
84         if (*arg)
85                 refmap_array[refmap_nr++] = arg;
86         return 0;
87 }
88
89 static struct option builtin_fetch_options[] = {
90         OPT__VERBOSITY(&verbosity),
91         OPT_BOOL(0, "all", &all,
92                  N_("fetch from all remotes")),
93         OPT_BOOL('a', "append", &append,
94                  N_("append to .git/FETCH_HEAD instead of overwriting")),
95         OPT_STRING(0, "upload-pack", &upload_pack, N_("path"),
96                    N_("path to upload pack on remote end")),
97         OPT__FORCE(&force, N_("force overwrite of local branch")),
98         OPT_BOOL('m', "multiple", &multiple,
99                  N_("fetch from multiple remotes")),
100         OPT_SET_INT('t', "tags", &tags,
101                     N_("fetch all tags and associated objects"), TAGS_SET),
102         OPT_SET_INT('n', NULL, &tags,
103                     N_("do not fetch all tags (--no-tags)"), TAGS_UNSET),
104         OPT_INTEGER('j', "jobs", &max_children,
105                     N_("number of submodules fetched in parallel")),
106         OPT_BOOL('p', "prune", &prune,
107                  N_("prune remote-tracking branches no longer on remote")),
108         { OPTION_CALLBACK, 0, "recurse-submodules", NULL, N_("on-demand"),
109                     N_("control recursive fetching of submodules"),
110                     PARSE_OPT_OPTARG, option_parse_recurse_submodules },
111         OPT_BOOL(0, "dry-run", &dry_run,
112                  N_("dry run")),
113         OPT_BOOL('k', "keep", &keep, N_("keep downloaded pack")),
114         OPT_BOOL('u', "update-head-ok", &update_head_ok,
115                     N_("allow updating of HEAD ref")),
116         OPT_BOOL(0, "progress", &progress, N_("force progress reporting")),
117         OPT_STRING(0, "depth", &depth, N_("depth"),
118                    N_("deepen history of shallow clone")),
119         { OPTION_SET_INT, 0, "unshallow", &unshallow, NULL,
120                    N_("convert to a complete repository"),
121                    PARSE_OPT_NONEG | PARSE_OPT_NOARG, NULL, 1 },
122         { OPTION_STRING, 0, "submodule-prefix", &submodule_prefix, N_("dir"),
123                    N_("prepend this to submodule path output"), PARSE_OPT_HIDDEN },
124         { OPTION_STRING, 0, "recurse-submodules-default",
125                    &recurse_submodules_default, NULL,
126                    N_("default mode for recursion"), PARSE_OPT_HIDDEN },
127         OPT_BOOL(0, "update-shallow", &update_shallow,
128                  N_("accept refs that update .git/shallow")),
129         { OPTION_CALLBACK, 0, "refmap", NULL, N_("refmap"),
130           N_("specify fetch refmap"), PARSE_OPT_NONEG, parse_refmap_arg },
131         OPT_SET_INT('4', "ipv4", &family, N_("use IPv4 addresses only"),
132                         TRANSPORT_FAMILY_IPV4),
133         OPT_SET_INT('6', "ipv6", &family, N_("use IPv6 addresses only"),
134                         TRANSPORT_FAMILY_IPV6),
135         OPT_END()
136 };
137
138 static void unlock_pack(void)
139 {
140         if (gtransport)
141                 transport_unlock_pack(gtransport);
142         if (gsecondary)
143                 transport_unlock_pack(gsecondary);
144 }
145
146 static void unlock_pack_on_signal(int signo)
147 {
148         unlock_pack();
149         sigchain_pop(signo);
150         raise(signo);
151 }
152
153 static void add_merge_config(struct ref **head,
154                            const struct ref *remote_refs,
155                            struct branch *branch,
156                            struct ref ***tail)
157 {
158         int i;
159
160         for (i = 0; i < branch->merge_nr; i++) {
161                 struct ref *rm, **old_tail = *tail;
162                 struct refspec refspec;
163
164                 for (rm = *head; rm; rm = rm->next) {
165                         if (branch_merge_matches(branch, i, rm->name)) {
166                                 rm->fetch_head_status = FETCH_HEAD_MERGE;
167                                 break;
168                         }
169                 }
170                 if (rm)
171                         continue;
172
173                 /*
174                  * Not fetched to a remote-tracking branch?  We need to fetch
175                  * it anyway to allow this branch's "branch.$name.merge"
176                  * to be honored by 'git pull', but we do not have to
177                  * fail if branch.$name.merge is misconfigured to point
178                  * at a nonexisting branch.  If we were indeed called by
179                  * 'git pull', it will notice the misconfiguration because
180                  * there is no entry in the resulting FETCH_HEAD marked
181                  * for merging.
182                  */
183                 memset(&refspec, 0, sizeof(refspec));
184                 refspec.src = branch->merge[i]->src;
185                 get_fetch_map(remote_refs, &refspec, tail, 1);
186                 for (rm = *old_tail; rm; rm = rm->next)
187                         rm->fetch_head_status = FETCH_HEAD_MERGE;
188         }
189 }
190
191 static int add_existing(const char *refname, const struct object_id *oid,
192                         int flag, void *cbdata)
193 {
194         struct string_list *list = (struct string_list *)cbdata;
195         struct string_list_item *item = string_list_insert(list, refname);
196         struct object_id *old_oid = xmalloc(sizeof(*old_oid));
197
198         oidcpy(old_oid, oid);
199         item->util = old_oid;
200         return 0;
201 }
202
203 static int will_fetch(struct ref **head, const unsigned char *sha1)
204 {
205         struct ref *rm = *head;
206         while (rm) {
207                 if (!hashcmp(rm->old_oid.hash, sha1))
208                         return 1;
209                 rm = rm->next;
210         }
211         return 0;
212 }
213
214 static void find_non_local_tags(struct transport *transport,
215                         struct ref **head,
216                         struct ref ***tail)
217 {
218         struct string_list existing_refs = STRING_LIST_INIT_DUP;
219         struct string_list remote_refs = STRING_LIST_INIT_NODUP;
220         const struct ref *ref;
221         struct string_list_item *item = NULL;
222
223         for_each_ref(add_existing, &existing_refs);
224         for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
225                 if (!starts_with(ref->name, "refs/tags/"))
226                         continue;
227
228                 /*
229                  * The peeled ref always follows the matching base
230                  * ref, so if we see a peeled ref that we don't want
231                  * to fetch then we can mark the ref entry in the list
232                  * as one to ignore by setting util to NULL.
233                  */
234                 if (ends_with(ref->name, "^{}")) {
235                         if (item && !has_object_file(&ref->old_oid) &&
236                             !will_fetch(head, ref->old_oid.hash) &&
237                             !has_sha1_file(item->util) &&
238                             !will_fetch(head, item->util))
239                                 item->util = NULL;
240                         item = NULL;
241                         continue;
242                 }
243
244                 /*
245                  * If item is non-NULL here, then we previously saw a
246                  * ref not followed by a peeled reference, so we need
247                  * to check if it is a lightweight tag that we want to
248                  * fetch.
249                  */
250                 if (item && !has_sha1_file(item->util) &&
251                     !will_fetch(head, item->util))
252                         item->util = NULL;
253
254                 item = NULL;
255
256                 /* skip duplicates and refs that we already have */
257                 if (string_list_has_string(&remote_refs, ref->name) ||
258                     string_list_has_string(&existing_refs, ref->name))
259                         continue;
260
261                 item = string_list_insert(&remote_refs, ref->name);
262                 item->util = (void *)&ref->old_oid;
263         }
264         string_list_clear(&existing_refs, 1);
265
266         /*
267          * We may have a final lightweight tag that needs to be
268          * checked to see if it needs fetching.
269          */
270         if (item && !has_sha1_file(item->util) &&
271             !will_fetch(head, item->util))
272                 item->util = NULL;
273
274         /*
275          * For all the tags in the remote_refs string list,
276          * add them to the list of refs to be fetched
277          */
278         for_each_string_list_item(item, &remote_refs) {
279                 /* Unless we have already decided to ignore this item... */
280                 if (item->util)
281                 {
282                         struct ref *rm = alloc_ref(item->string);
283                         rm->peer_ref = alloc_ref(item->string);
284                         oidcpy(&rm->old_oid, item->util);
285                         **tail = rm;
286                         *tail = &rm->next;
287                 }
288         }
289
290         string_list_clear(&remote_refs, 0);
291 }
292
293 static struct ref *get_ref_map(struct transport *transport,
294                                struct refspec *refspecs, int refspec_count,
295                                int tags, int *autotags)
296 {
297         int i;
298         struct ref *rm;
299         struct ref *ref_map = NULL;
300         struct ref **tail = &ref_map;
301
302         /* opportunistically-updated references: */
303         struct ref *orefs = NULL, **oref_tail = &orefs;
304
305         const struct ref *remote_refs = transport_get_remote_refs(transport);
306
307         if (refspec_count) {
308                 struct refspec *fetch_refspec;
309                 int fetch_refspec_nr;
310
311                 for (i = 0; i < refspec_count; i++) {
312                         get_fetch_map(remote_refs, &refspecs[i], &tail, 0);
313                         if (refspecs[i].dst && refspecs[i].dst[0])
314                                 *autotags = 1;
315                 }
316                 /* Merge everything on the command line (but not --tags) */
317                 for (rm = ref_map; rm; rm = rm->next)
318                         rm->fetch_head_status = FETCH_HEAD_MERGE;
319
320                 /*
321                  * For any refs that we happen to be fetching via
322                  * command-line arguments, the destination ref might
323                  * have been missing or have been different than the
324                  * remote-tracking ref that would be derived from the
325                  * configured refspec.  In these cases, we want to
326                  * take the opportunity to update their configured
327                  * remote-tracking reference.  However, we do not want
328                  * to mention these entries in FETCH_HEAD at all, as
329                  * they would simply be duplicates of existing
330                  * entries, so we set them FETCH_HEAD_IGNORE below.
331                  *
332                  * We compute these entries now, based only on the
333                  * refspecs specified on the command line.  But we add
334                  * them to the list following the refspecs resulting
335                  * from the tags option so that one of the latter,
336                  * which has FETCH_HEAD_NOT_FOR_MERGE, is not removed
337                  * by ref_remove_duplicates() in favor of one of these
338                  * opportunistic entries with FETCH_HEAD_IGNORE.
339                  */
340                 if (refmap_array) {
341                         fetch_refspec = parse_fetch_refspec(refmap_nr, refmap_array);
342                         fetch_refspec_nr = refmap_nr;
343                 } else {
344                         fetch_refspec = transport->remote->fetch;
345                         fetch_refspec_nr = transport->remote->fetch_refspec_nr;
346                 }
347
348                 for (i = 0; i < fetch_refspec_nr; i++)
349                         get_fetch_map(ref_map, &fetch_refspec[i], &oref_tail, 1);
350         } else if (refmap_array) {
351                 die("--refmap option is only meaningful with command-line refspec(s).");
352         } else {
353                 /* Use the defaults */
354                 struct remote *remote = transport->remote;
355                 struct branch *branch = branch_get(NULL);
356                 int has_merge = branch_has_merge_config(branch);
357                 if (remote &&
358                     (remote->fetch_refspec_nr ||
359                      /* Note: has_merge implies non-NULL branch->remote_name */
360                      (has_merge && !strcmp(branch->remote_name, remote->name)))) {
361                         for (i = 0; i < remote->fetch_refspec_nr; i++) {
362                                 get_fetch_map(remote_refs, &remote->fetch[i], &tail, 0);
363                                 if (remote->fetch[i].dst &&
364                                     remote->fetch[i].dst[0])
365                                         *autotags = 1;
366                                 if (!i && !has_merge && ref_map &&
367                                     !remote->fetch[0].pattern)
368                                         ref_map->fetch_head_status = FETCH_HEAD_MERGE;
369                         }
370                         /*
371                          * if the remote we're fetching from is the same
372                          * as given in branch.<name>.remote, we add the
373                          * ref given in branch.<name>.merge, too.
374                          *
375                          * Note: has_merge implies non-NULL branch->remote_name
376                          */
377                         if (has_merge &&
378                             !strcmp(branch->remote_name, remote->name))
379                                 add_merge_config(&ref_map, remote_refs, branch, &tail);
380                 } else {
381                         ref_map = get_remote_ref(remote_refs, "HEAD");
382                         if (!ref_map)
383                                 die(_("Couldn't find remote ref HEAD"));
384                         ref_map->fetch_head_status = FETCH_HEAD_MERGE;
385                         tail = &ref_map->next;
386                 }
387         }
388
389         if (tags == TAGS_SET)
390                 /* also fetch all tags */
391                 get_fetch_map(remote_refs, tag_refspec, &tail, 0);
392         else if (tags == TAGS_DEFAULT && *autotags)
393                 find_non_local_tags(transport, &ref_map, &tail);
394
395         /* Now append any refs to be updated opportunistically: */
396         *tail = orefs;
397         for (rm = orefs; rm; rm = rm->next) {
398                 rm->fetch_head_status = FETCH_HEAD_IGNORE;
399                 tail = &rm->next;
400         }
401
402         return ref_remove_duplicates(ref_map);
403 }
404
405 #define STORE_REF_ERROR_OTHER 1
406 #define STORE_REF_ERROR_DF_CONFLICT 2
407
408 static int s_update_ref(const char *action,
409                         struct ref *ref,
410                         int check_old)
411 {
412         char msg[1024];
413         char *rla = getenv("GIT_REFLOG_ACTION");
414         struct ref_transaction *transaction;
415         struct strbuf err = STRBUF_INIT;
416         int ret, df_conflict = 0;
417
418         if (dry_run)
419                 return 0;
420         if (!rla)
421                 rla = default_rla.buf;
422         snprintf(msg, sizeof(msg), "%s: %s", rla, action);
423
424         transaction = ref_transaction_begin(&err);
425         if (!transaction ||
426             ref_transaction_update(transaction, ref->name,
427                                    ref->new_oid.hash,
428                                    check_old ? ref->old_oid.hash : NULL,
429                                    0, msg, &err))
430                 goto fail;
431
432         ret = ref_transaction_commit(transaction, &err);
433         if (ret) {
434                 df_conflict = (ret == TRANSACTION_NAME_CONFLICT);
435                 goto fail;
436         }
437
438         ref_transaction_free(transaction);
439         strbuf_release(&err);
440         return 0;
441 fail:
442         ref_transaction_free(transaction);
443         error("%s", err.buf);
444         strbuf_release(&err);
445         return df_conflict ? STORE_REF_ERROR_DF_CONFLICT
446                            : STORE_REF_ERROR_OTHER;
447 }
448
449 #define REFCOL_WIDTH  10
450
451 static int update_local_ref(struct ref *ref,
452                             const char *remote,
453                             const struct ref *remote_ref,
454                             struct strbuf *display)
455 {
456         struct commit *current = NULL, *updated;
457         enum object_type type;
458         struct branch *current_branch = branch_get(NULL);
459         const char *pretty_ref = prettify_refname(ref->name);
460
461         type = sha1_object_info(ref->new_oid.hash, NULL);
462         if (type < 0)
463                 die(_("object %s not found"), oid_to_hex(&ref->new_oid));
464
465         if (!oidcmp(&ref->old_oid, &ref->new_oid)) {
466                 if (verbosity > 0)
467                         strbuf_addf(display, "= %-*s %-*s -> %s",
468                                     TRANSPORT_SUMMARY(_("[up to date]")),
469                                     REFCOL_WIDTH, remote, pretty_ref);
470                 return 0;
471         }
472
473         if (current_branch &&
474             !strcmp(ref->name, current_branch->name) &&
475             !(update_head_ok || is_bare_repository()) &&
476             !is_null_oid(&ref->old_oid)) {
477                 /*
478                  * If this is the head, and it's not okay to update
479                  * the head, and the old value of the head isn't empty...
480                  */
481                 strbuf_addf(display,
482                             _("! %-*s %-*s -> %s  (can't fetch in current branch)"),
483                             TRANSPORT_SUMMARY(_("[rejected]")),
484                             REFCOL_WIDTH, remote, pretty_ref);
485                 return 1;
486         }
487
488         if (!is_null_oid(&ref->old_oid) &&
489             starts_with(ref->name, "refs/tags/")) {
490                 int r;
491                 r = s_update_ref("updating tag", ref, 0);
492                 strbuf_addf(display, "%c %-*s %-*s -> %s%s",
493                             r ? '!' : '-',
494                             TRANSPORT_SUMMARY(_("[tag update]")),
495                             REFCOL_WIDTH, remote, pretty_ref,
496                             r ? _("  (unable to update local ref)") : "");
497                 return r;
498         }
499
500         current = lookup_commit_reference_gently(ref->old_oid.hash, 1);
501         updated = lookup_commit_reference_gently(ref->new_oid.hash, 1);
502         if (!current || !updated) {
503                 const char *msg;
504                 const char *what;
505                 int r;
506                 /*
507                  * Nicely describe the new ref we're fetching.
508                  * Base this on the remote's ref name, as it's
509                  * more likely to follow a standard layout.
510                  */
511                 const char *name = remote_ref ? remote_ref->name : "";
512                 if (starts_with(name, "refs/tags/")) {
513                         msg = "storing tag";
514                         what = _("[new tag]");
515                 } else if (starts_with(name, "refs/heads/")) {
516                         msg = "storing head";
517                         what = _("[new branch]");
518                 } else {
519                         msg = "storing ref";
520                         what = _("[new ref]");
521                 }
522
523                 if ((recurse_submodules != RECURSE_SUBMODULES_OFF) &&
524                     (recurse_submodules != RECURSE_SUBMODULES_ON))
525                         check_for_new_submodule_commits(ref->new_oid.hash);
526                 r = s_update_ref(msg, ref, 0);
527                 strbuf_addf(display, "%c %-*s %-*s -> %s%s",
528                             r ? '!' : '*',
529                             TRANSPORT_SUMMARY(what),
530                             REFCOL_WIDTH, remote, pretty_ref,
531                             r ? _("  (unable to update local ref)") : "");
532                 return r;
533         }
534
535         if (in_merge_bases(current, updated)) {
536                 struct strbuf quickref = STRBUF_INIT;
537                 int r;
538                 strbuf_add_unique_abbrev(&quickref, current->object.oid.hash, DEFAULT_ABBREV);
539                 strbuf_addstr(&quickref, "..");
540                 strbuf_add_unique_abbrev(&quickref, ref->new_oid.hash, DEFAULT_ABBREV);
541                 if ((recurse_submodules != RECURSE_SUBMODULES_OFF) &&
542                     (recurse_submodules != RECURSE_SUBMODULES_ON))
543                         check_for_new_submodule_commits(ref->new_oid.hash);
544                 r = s_update_ref("fast-forward", ref, 1);
545                 strbuf_addf(display, "%c %-*s %-*s -> %s%s",
546                             r ? '!' : ' ',
547                             TRANSPORT_SUMMARY_WIDTH, quickref.buf,
548                             REFCOL_WIDTH, remote, pretty_ref,
549                             r ? _("  (unable to update local ref)") : "");
550                 strbuf_release(&quickref);
551                 return r;
552         } else if (force || ref->force) {
553                 struct strbuf quickref = STRBUF_INIT;
554                 int r;
555                 strbuf_add_unique_abbrev(&quickref, current->object.oid.hash, DEFAULT_ABBREV);
556                 strbuf_addstr(&quickref, "...");
557                 strbuf_add_unique_abbrev(&quickref, ref->new_oid.hash, DEFAULT_ABBREV);
558                 if ((recurse_submodules != RECURSE_SUBMODULES_OFF) &&
559                     (recurse_submodules != RECURSE_SUBMODULES_ON))
560                         check_for_new_submodule_commits(ref->new_oid.hash);
561                 r = s_update_ref("forced-update", ref, 1);
562                 strbuf_addf(display, "%c %-*s %-*s -> %s  (%s)",
563                             r ? '!' : '+',
564                             TRANSPORT_SUMMARY_WIDTH, quickref.buf,
565                             REFCOL_WIDTH, remote, pretty_ref,
566                             r ? _("unable to update local ref") : _("forced update"));
567                 strbuf_release(&quickref);
568                 return r;
569         } else {
570                 strbuf_addf(display, "! %-*s %-*s -> %s  %s",
571                             TRANSPORT_SUMMARY(_("[rejected]")),
572                             REFCOL_WIDTH, remote, pretty_ref,
573                             _("(non-fast-forward)"));
574                 return 1;
575         }
576 }
577
578 static int iterate_ref_map(void *cb_data, unsigned char sha1[20])
579 {
580         struct ref **rm = cb_data;
581         struct ref *ref = *rm;
582
583         while (ref && ref->status == REF_STATUS_REJECT_SHALLOW)
584                 ref = ref->next;
585         if (!ref)
586                 return -1; /* end of the list */
587         *rm = ref->next;
588         hashcpy(sha1, ref->old_oid.hash);
589         return 0;
590 }
591
592 static int store_updated_refs(const char *raw_url, const char *remote_name,
593                 struct ref *ref_map)
594 {
595         FILE *fp;
596         struct commit *commit;
597         int url_len, i, rc = 0;
598         struct strbuf note = STRBUF_INIT;
599         const char *what, *kind;
600         struct ref *rm;
601         char *url;
602         const char *filename = dry_run ? "/dev/null" : git_path_fetch_head();
603         int want_status;
604
605         fp = fopen(filename, "a");
606         if (!fp)
607                 return error(_("cannot open %s: %s\n"), filename, strerror(errno));
608
609         if (raw_url)
610                 url = transport_anonymize_url(raw_url);
611         else
612                 url = xstrdup("foreign");
613
614         rm = ref_map;
615         if (check_everything_connected(iterate_ref_map, 0, &rm)) {
616                 rc = error(_("%s did not send all necessary objects\n"), url);
617                 goto abort;
618         }
619
620         /*
621          * We do a pass for each fetch_head_status type in their enum order, so
622          * merged entries are written before not-for-merge. That lets readers
623          * use FETCH_HEAD as a refname to refer to the ref to be merged.
624          */
625         for (want_status = FETCH_HEAD_MERGE;
626              want_status <= FETCH_HEAD_IGNORE;
627              want_status++) {
628                 for (rm = ref_map; rm; rm = rm->next) {
629                         struct ref *ref = NULL;
630                         const char *merge_status_marker = "";
631
632                         if (rm->status == REF_STATUS_REJECT_SHALLOW) {
633                                 if (want_status == FETCH_HEAD_MERGE)
634                                         warning(_("reject %s because shallow roots are not allowed to be updated"),
635                                                 rm->peer_ref ? rm->peer_ref->name : rm->name);
636                                 continue;
637                         }
638
639                         commit = lookup_commit_reference_gently(rm->old_oid.hash, 1);
640                         if (!commit)
641                                 rm->fetch_head_status = FETCH_HEAD_NOT_FOR_MERGE;
642
643                         if (rm->fetch_head_status != want_status)
644                                 continue;
645
646                         if (rm->peer_ref) {
647                                 ref = alloc_ref(rm->peer_ref->name);
648                                 oidcpy(&ref->old_oid, &rm->peer_ref->old_oid);
649                                 oidcpy(&ref->new_oid, &rm->old_oid);
650                                 ref->force = rm->peer_ref->force;
651                         }
652
653
654                         if (!strcmp(rm->name, "HEAD")) {
655                                 kind = "";
656                                 what = "";
657                         }
658                         else if (starts_with(rm->name, "refs/heads/")) {
659                                 kind = "branch";
660                                 what = rm->name + 11;
661                         }
662                         else if (starts_with(rm->name, "refs/tags/")) {
663                                 kind = "tag";
664                                 what = rm->name + 10;
665                         }
666                         else if (starts_with(rm->name, "refs/remotes/")) {
667                                 kind = "remote-tracking branch";
668                                 what = rm->name + 13;
669                         }
670                         else {
671                                 kind = "";
672                                 what = rm->name;
673                         }
674
675                         url_len = strlen(url);
676                         for (i = url_len - 1; url[i] == '/' && 0 <= i; i--)
677                                 ;
678                         url_len = i + 1;
679                         if (4 < i && !strncmp(".git", url + i - 3, 4))
680                                 url_len = i - 3;
681
682                         strbuf_reset(&note);
683                         if (*what) {
684                                 if (*kind)
685                                         strbuf_addf(&note, "%s ", kind);
686                                 strbuf_addf(&note, "'%s' of ", what);
687                         }
688                         switch (rm->fetch_head_status) {
689                         case FETCH_HEAD_NOT_FOR_MERGE:
690                                 merge_status_marker = "not-for-merge";
691                                 /* fall-through */
692                         case FETCH_HEAD_MERGE:
693                                 fprintf(fp, "%s\t%s\t%s",
694                                         oid_to_hex(&rm->old_oid),
695                                         merge_status_marker,
696                                         note.buf);
697                                 for (i = 0; i < url_len; ++i)
698                                         if ('\n' == url[i])
699                                                 fputs("\\n", fp);
700                                         else
701                                                 fputc(url[i], fp);
702                                 fputc('\n', fp);
703                                 break;
704                         default:
705                                 /* do not write anything to FETCH_HEAD */
706                                 break;
707                         }
708
709                         strbuf_reset(&note);
710                         if (ref) {
711                                 rc |= update_local_ref(ref, what, rm, &note);
712                                 free(ref);
713                         } else
714                                 strbuf_addf(&note, "* %-*s %-*s -> FETCH_HEAD",
715                                             TRANSPORT_SUMMARY_WIDTH,
716                                             *kind ? kind : "branch",
717                                             REFCOL_WIDTH,
718                                             *what ? what : "HEAD");
719                         if (note.len) {
720                                 if (verbosity >= 0 && !shown_url) {
721                                         fprintf(stderr, _("From %.*s\n"),
722                                                         url_len, url);
723                                         shown_url = 1;
724                                 }
725                                 if (verbosity >= 0)
726                                         fprintf(stderr, " %s\n", note.buf);
727                         }
728                 }
729         }
730
731         if (rc & STORE_REF_ERROR_DF_CONFLICT)
732                 error(_("some local refs could not be updated; try running\n"
733                       " 'git remote prune %s' to remove any old, conflicting "
734                       "branches"), remote_name);
735
736  abort:
737         strbuf_release(&note);
738         free(url);
739         fclose(fp);
740         return rc;
741 }
742
743 /*
744  * We would want to bypass the object transfer altogether if
745  * everything we are going to fetch already exists and is connected
746  * locally.
747  */
748 static int quickfetch(struct ref *ref_map)
749 {
750         struct ref *rm = ref_map;
751
752         /*
753          * If we are deepening a shallow clone we already have these
754          * objects reachable.  Running rev-list here will return with
755          * a good (0) exit status and we'll bypass the fetch that we
756          * really need to perform.  Claiming failure now will ensure
757          * we perform the network exchange to deepen our history.
758          */
759         if (depth)
760                 return -1;
761         return check_everything_connected(iterate_ref_map, 1, &rm);
762 }
763
764 static int fetch_refs(struct transport *transport, struct ref *ref_map)
765 {
766         int ret = quickfetch(ref_map);
767         if (ret)
768                 ret = transport_fetch_refs(transport, ref_map);
769         if (!ret)
770                 ret |= store_updated_refs(transport->url,
771                                 transport->remote->name,
772                                 ref_map);
773         transport_unlock_pack(transport);
774         return ret;
775 }
776
777 static int prune_refs(struct refspec *refs, int ref_count, struct ref *ref_map,
778                 const char *raw_url)
779 {
780         int url_len, i, result = 0;
781         struct ref *ref, *stale_refs = get_stale_heads(refs, ref_count, ref_map);
782         char *url;
783         const char *dangling_msg = dry_run
784                 ? _("   (%s will become dangling)")
785                 : _("   (%s has become dangling)");
786
787         if (raw_url)
788                 url = transport_anonymize_url(raw_url);
789         else
790                 url = xstrdup("foreign");
791
792         url_len = strlen(url);
793         for (i = url_len - 1; url[i] == '/' && 0 <= i; i--)
794                 ;
795
796         url_len = i + 1;
797         if (4 < i && !strncmp(".git", url + i - 3, 4))
798                 url_len = i - 3;
799
800         if (!dry_run) {
801                 struct string_list refnames = STRING_LIST_INIT_NODUP;
802
803                 for (ref = stale_refs; ref; ref = ref->next)
804                         string_list_append(&refnames, ref->name);
805
806                 result = delete_refs(&refnames);
807                 string_list_clear(&refnames, 0);
808         }
809
810         if (verbosity >= 0) {
811                 for (ref = stale_refs; ref; ref = ref->next) {
812                         if (!shown_url) {
813                                 fprintf(stderr, _("From %.*s\n"), url_len, url);
814                                 shown_url = 1;
815                         }
816                         fprintf(stderr, " x %-*s %-*s -> %s\n",
817                                 TRANSPORT_SUMMARY(_("[deleted]")),
818                                 REFCOL_WIDTH, _("(none)"), prettify_refname(ref->name));
819                         warn_dangling_symref(stderr, dangling_msg, ref->name);
820                 }
821         }
822
823         free(url);
824         free_refs(stale_refs);
825         return result;
826 }
827
828 static void check_not_current_branch(struct ref *ref_map)
829 {
830         struct branch *current_branch = branch_get(NULL);
831
832         if (is_bare_repository() || !current_branch)
833                 return;
834
835         for (; ref_map; ref_map = ref_map->next)
836                 if (ref_map->peer_ref && !strcmp(current_branch->refname,
837                                         ref_map->peer_ref->name))
838                         die(_("Refusing to fetch into current branch %s "
839                             "of non-bare repository"), current_branch->refname);
840 }
841
842 static int truncate_fetch_head(void)
843 {
844         const char *filename = git_path_fetch_head();
845         FILE *fp = fopen_for_writing(filename);
846
847         if (!fp)
848                 return error(_("cannot open %s: %s\n"), filename, strerror(errno));
849         fclose(fp);
850         return 0;
851 }
852
853 static void set_option(struct transport *transport, const char *name, const char *value)
854 {
855         int r = transport_set_option(transport, name, value);
856         if (r < 0)
857                 die(_("Option \"%s\" value \"%s\" is not valid for %s"),
858                     name, value, transport->url);
859         if (r > 0)
860                 warning(_("Option \"%s\" is ignored for %s\n"),
861                         name, transport->url);
862 }
863
864 static struct transport *prepare_transport(struct remote *remote)
865 {
866         struct transport *transport;
867         transport = transport_get(remote, NULL);
868         transport_set_verbosity(transport, verbosity, progress);
869         transport->family = family;
870         if (upload_pack)
871                 set_option(transport, TRANS_OPT_UPLOADPACK, upload_pack);
872         if (keep)
873                 set_option(transport, TRANS_OPT_KEEP, "yes");
874         if (depth)
875                 set_option(transport, TRANS_OPT_DEPTH, depth);
876         if (update_shallow)
877                 set_option(transport, TRANS_OPT_UPDATE_SHALLOW, "yes");
878         return transport;
879 }
880
881 static void backfill_tags(struct transport *transport, struct ref *ref_map)
882 {
883         if (transport->cannot_reuse) {
884                 gsecondary = prepare_transport(transport->remote);
885                 transport = gsecondary;
886         }
887
888         transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, NULL);
889         transport_set_option(transport, TRANS_OPT_DEPTH, "0");
890         fetch_refs(transport, ref_map);
891
892         if (gsecondary) {
893                 transport_disconnect(gsecondary);
894                 gsecondary = NULL;
895         }
896 }
897
898 static int do_fetch(struct transport *transport,
899                     struct refspec *refs, int ref_count)
900 {
901         struct string_list existing_refs = STRING_LIST_INIT_DUP;
902         struct ref *ref_map;
903         struct ref *rm;
904         int autotags = (transport->remote->fetch_tags == 1);
905         int retcode = 0;
906
907         for_each_ref(add_existing, &existing_refs);
908
909         if (tags == TAGS_DEFAULT) {
910                 if (transport->remote->fetch_tags == 2)
911                         tags = TAGS_SET;
912                 if (transport->remote->fetch_tags == -1)
913                         tags = TAGS_UNSET;
914         }
915
916         if (!transport->get_refs_list || !transport->fetch)
917                 die(_("Don't know how to fetch from %s"), transport->url);
918
919         /* if not appending, truncate FETCH_HEAD */
920         if (!append && !dry_run) {
921                 retcode = truncate_fetch_head();
922                 if (retcode)
923                         goto cleanup;
924         }
925
926         ref_map = get_ref_map(transport, refs, ref_count, tags, &autotags);
927         if (!update_head_ok)
928                 check_not_current_branch(ref_map);
929
930         for (rm = ref_map; rm; rm = rm->next) {
931                 if (rm->peer_ref) {
932                         struct string_list_item *peer_item =
933                                 string_list_lookup(&existing_refs,
934                                                    rm->peer_ref->name);
935                         if (peer_item) {
936                                 struct object_id *old_oid = peer_item->util;
937                                 oidcpy(&rm->peer_ref->old_oid, old_oid);
938                         }
939                 }
940         }
941
942         if (tags == TAGS_DEFAULT && autotags)
943                 transport_set_option(transport, TRANS_OPT_FOLLOWTAGS, "1");
944         if (prune) {
945                 /*
946                  * We only prune based on refspecs specified
947                  * explicitly (via command line or configuration); we
948                  * don't care whether --tags was specified.
949                  */
950                 if (ref_count) {
951                         prune_refs(refs, ref_count, ref_map, transport->url);
952                 } else {
953                         prune_refs(transport->remote->fetch,
954                                    transport->remote->fetch_refspec_nr,
955                                    ref_map,
956                                    transport->url);
957                 }
958         }
959         if (fetch_refs(transport, ref_map)) {
960                 free_refs(ref_map);
961                 retcode = 1;
962                 goto cleanup;
963         }
964         free_refs(ref_map);
965
966         /* if neither --no-tags nor --tags was specified, do automated tag
967          * following ... */
968         if (tags == TAGS_DEFAULT && autotags) {
969                 struct ref **tail = &ref_map;
970                 ref_map = NULL;
971                 find_non_local_tags(transport, &ref_map, &tail);
972                 if (ref_map)
973                         backfill_tags(transport, ref_map);
974                 free_refs(ref_map);
975         }
976
977  cleanup:
978         string_list_clear(&existing_refs, 1);
979         return retcode;
980 }
981
982 static int get_one_remote_for_fetch(struct remote *remote, void *priv)
983 {
984         struct string_list *list = priv;
985         if (!remote->skip_default_update)
986                 string_list_append(list, remote->name);
987         return 0;
988 }
989
990 struct remote_group_data {
991         const char *name;
992         struct string_list *list;
993 };
994
995 static int get_remote_group(const char *key, const char *value, void *priv)
996 {
997         struct remote_group_data *g = priv;
998
999         if (skip_prefix(key, "remotes.", &key) && !strcmp(key, g->name)) {
1000                 /* split list by white space */
1001                 while (*value) {
1002                         size_t wordlen = strcspn(value, " \t\n");
1003
1004                         if (wordlen >= 1)
1005                                 string_list_append(g->list,
1006                                                    xstrndup(value, wordlen));
1007                         value += wordlen + (value[wordlen] != '\0');
1008                 }
1009         }
1010
1011         return 0;
1012 }
1013
1014 static int add_remote_or_group(const char *name, struct string_list *list)
1015 {
1016         int prev_nr = list->nr;
1017         struct remote_group_data g;
1018         g.name = name; g.list = list;
1019
1020         git_config(get_remote_group, &g);
1021         if (list->nr == prev_nr) {
1022                 struct remote *remote = remote_get(name);
1023                 if (!remote_is_configured(remote))
1024                         return 0;
1025                 string_list_append(list, remote->name);
1026         }
1027         return 1;
1028 }
1029
1030 static void add_options_to_argv(struct argv_array *argv)
1031 {
1032         if (dry_run)
1033                 argv_array_push(argv, "--dry-run");
1034         if (prune != -1)
1035                 argv_array_push(argv, prune ? "--prune" : "--no-prune");
1036         if (update_head_ok)
1037                 argv_array_push(argv, "--update-head-ok");
1038         if (force)
1039                 argv_array_push(argv, "--force");
1040         if (keep)
1041                 argv_array_push(argv, "--keep");
1042         if (recurse_submodules == RECURSE_SUBMODULES_ON)
1043                 argv_array_push(argv, "--recurse-submodules");
1044         else if (recurse_submodules == RECURSE_SUBMODULES_ON_DEMAND)
1045                 argv_array_push(argv, "--recurse-submodules=on-demand");
1046         if (tags == TAGS_SET)
1047                 argv_array_push(argv, "--tags");
1048         else if (tags == TAGS_UNSET)
1049                 argv_array_push(argv, "--no-tags");
1050         if (verbosity >= 2)
1051                 argv_array_push(argv, "-v");
1052         if (verbosity >= 1)
1053                 argv_array_push(argv, "-v");
1054         else if (verbosity < 0)
1055                 argv_array_push(argv, "-q");
1056
1057 }
1058
1059 static int fetch_multiple(struct string_list *list)
1060 {
1061         int i, result = 0;
1062         struct argv_array argv = ARGV_ARRAY_INIT;
1063
1064         if (!append && !dry_run) {
1065                 int errcode = truncate_fetch_head();
1066                 if (errcode)
1067                         return errcode;
1068         }
1069
1070         argv_array_pushl(&argv, "fetch", "--append", NULL);
1071         add_options_to_argv(&argv);
1072
1073         for (i = 0; i < list->nr; i++) {
1074                 const char *name = list->items[i].string;
1075                 argv_array_push(&argv, name);
1076                 if (verbosity >= 0)
1077                         printf(_("Fetching %s\n"), name);
1078                 if (run_command_v_opt(argv.argv, RUN_GIT_CMD)) {
1079                         error(_("Could not fetch %s"), name);
1080                         result = 1;
1081                 }
1082                 argv_array_pop(&argv);
1083         }
1084
1085         argv_array_clear(&argv);
1086         return result;
1087 }
1088
1089 static int fetch_one(struct remote *remote, int argc, const char **argv)
1090 {
1091         static const char **refs = NULL;
1092         struct refspec *refspec;
1093         int ref_nr = 0;
1094         int exit_code;
1095
1096         if (!remote)
1097                 die(_("No remote repository specified.  Please, specify either a URL or a\n"
1098                     "remote name from which new revisions should be fetched."));
1099
1100         gtransport = prepare_transport(remote);
1101
1102         if (prune < 0) {
1103                 /* no command line request */
1104                 if (0 <= gtransport->remote->prune)
1105                         prune = gtransport->remote->prune;
1106                 else if (0 <= fetch_prune_config)
1107                         prune = fetch_prune_config;
1108                 else
1109                         prune = PRUNE_BY_DEFAULT;
1110         }
1111
1112         if (argc > 0) {
1113                 int j = 0;
1114                 int i;
1115                 refs = xcalloc(st_add(argc, 1), sizeof(const char *));
1116                 for (i = 0; i < argc; i++) {
1117                         if (!strcmp(argv[i], "tag")) {
1118                                 i++;
1119                                 if (i >= argc)
1120                                         die(_("You need to specify a tag name."));
1121                                 refs[j++] = xstrfmt("refs/tags/%s:refs/tags/%s",
1122                                                     argv[i], argv[i]);
1123                         } else
1124                                 refs[j++] = argv[i];
1125                 }
1126                 refs[j] = NULL;
1127                 ref_nr = j;
1128         }
1129
1130         sigchain_push_common(unlock_pack_on_signal);
1131         atexit(unlock_pack);
1132         refspec = parse_fetch_refspec(ref_nr, refs);
1133         exit_code = do_fetch(gtransport, refspec, ref_nr);
1134         free_refspec(ref_nr, refspec);
1135         transport_disconnect(gtransport);
1136         gtransport = NULL;
1137         return exit_code;
1138 }
1139
1140 int cmd_fetch(int argc, const char **argv, const char *prefix)
1141 {
1142         int i;
1143         struct string_list list = STRING_LIST_INIT_NODUP;
1144         struct remote *remote;
1145         int result = 0;
1146         struct argv_array argv_gc_auto = ARGV_ARRAY_INIT;
1147
1148         packet_trace_identity("fetch");
1149
1150         /* Record the command line for the reflog */
1151         strbuf_addstr(&default_rla, "fetch");
1152         for (i = 1; i < argc; i++)
1153                 strbuf_addf(&default_rla, " %s", argv[i]);
1154
1155         git_config(git_fetch_config, NULL);
1156
1157         argc = parse_options(argc, argv, prefix,
1158                              builtin_fetch_options, builtin_fetch_usage, 0);
1159
1160         if (unshallow) {
1161                 if (depth)
1162                         die(_("--depth and --unshallow cannot be used together"));
1163                 else if (!is_repository_shallow())
1164                         die(_("--unshallow on a complete repository does not make sense"));
1165                 else
1166                         depth = xstrfmt("%d", INFINITE_DEPTH);
1167         }
1168
1169         /* no need to be strict, transport_set_option() will validate it again */
1170         if (depth && atoi(depth) < 1)
1171                 die(_("depth %s is not a positive number"), depth);
1172
1173         if (recurse_submodules != RECURSE_SUBMODULES_OFF) {
1174                 if (recurse_submodules_default) {
1175                         int arg = parse_fetch_recurse_submodules_arg("--recurse-submodules-default", recurse_submodules_default);
1176                         set_config_fetch_recurse_submodules(arg);
1177                 }
1178                 gitmodules_config();
1179                 git_config(submodule_config, NULL);
1180         }
1181
1182         if (all) {
1183                 if (argc == 1)
1184                         die(_("fetch --all does not take a repository argument"));
1185                 else if (argc > 1)
1186                         die(_("fetch --all does not make sense with refspecs"));
1187                 (void) for_each_remote(get_one_remote_for_fetch, &list);
1188                 result = fetch_multiple(&list);
1189         } else if (argc == 0) {
1190                 /* No arguments -- use default remote */
1191                 remote = remote_get(NULL);
1192                 result = fetch_one(remote, argc, argv);
1193         } else if (multiple) {
1194                 /* All arguments are assumed to be remotes or groups */
1195                 for (i = 0; i < argc; i++)
1196                         if (!add_remote_or_group(argv[i], &list))
1197                                 die(_("No such remote or remote group: %s"), argv[i]);
1198                 result = fetch_multiple(&list);
1199         } else {
1200                 /* Single remote or group */
1201                 (void) add_remote_or_group(argv[0], &list);
1202                 if (list.nr > 1) {
1203                         /* More than one remote */
1204                         if (argc > 1)
1205                                 die(_("Fetching a group and specifying refspecs does not make sense"));
1206                         result = fetch_multiple(&list);
1207                 } else {
1208                         /* Zero or one remotes */
1209                         remote = remote_get(argv[0]);
1210                         result = fetch_one(remote, argc-1, argv+1);
1211                 }
1212         }
1213
1214         if (!result && (recurse_submodules != RECURSE_SUBMODULES_OFF)) {
1215                 struct argv_array options = ARGV_ARRAY_INIT;
1216
1217                 add_options_to_argv(&options);
1218                 result = fetch_populated_submodules(&options,
1219                                                     submodule_prefix,
1220                                                     recurse_submodules,
1221                                                     verbosity < 0,
1222                                                     max_children);
1223                 argv_array_clear(&options);
1224         }
1225
1226         /* All names were strdup()ed or strndup()ed */
1227         list.strdup_strings = 1;
1228         string_list_clear(&list, 0);
1229
1230         close_all_packs();
1231
1232         argv_array_pushl(&argv_gc_auto, "gc", "--auto", NULL);
1233         if (verbosity < 0)
1234                 argv_array_push(&argv_gc_auto, "--quiet");
1235         run_command_v_opt(argv_gc_auto.argv, RUN_GIT_CMD);
1236         argv_array_clear(&argv_gc_auto);
1237
1238         return result;
1239 }