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