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