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