builtin/fetch.c

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