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