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 "path-list.h"
   9 #include "remote.h"
  10 #include "transport.h"
  11 #include "run-command.h"
  12
  13 static const char fetch_usage[] = "git-fetch [-a | --append] [--upload-pack <upload-pack>] [-f | --force] [--no-tags] [-t | --tags] [-k | --keep] [-u | --update-head-ok] [--depth <depth>] [-v | --verbose] [<repository> <refspec>...]";
  14
  15 static int append, force, tags, no_tags, update_head_ok, verbose, quiet;
  16 static const char *depth;
  17 static char *default_rla = NULL;
  18 static struct transport *transport;
  19
  20 static void unlock_pack(void)
  21 {
  22         if (transport)
  23                 transport_unlock_pack(transport);
  24 }
  25
  26 static void unlock_pack_on_signal(int signo)
  27 {
  28         unlock_pack();
  29         signal(SIGINT, SIG_DFL);
  30         raise(signo);
  31 }
  32
  33 static void add_merge_config(struct ref **head,
  34                            const struct ref *remote_refs,
  35                            struct branch *branch,
  36                            struct ref ***tail)
  37 {
  38         int i;
  39
  40         for (i = 0; i < branch->merge_nr; i++) {
  41                 struct ref *rm, **old_tail = *tail;
  42                 struct refspec refspec;
  43
  44                 for (rm = *head; rm; rm = rm->next) {
  45                         if (branch_merge_matches(branch, i, rm->name)) {
  46                                 rm->merge = 1;
  47                                 break;
  48                         }
  49                 }
  50                 if (rm)
  51                         continue;
  52
  53                 /*
  54                  * Not fetched to a tracking branch?  We need to fetch
  55                  * it anyway to allow this branch's "branch.$name.merge"
  56                  * to be honored by git-pull, but we do not have to
  57                  * fail if branch.$name.merge is misconfigured to point
  58                  * at a nonexisting branch.  If we were indeed called by
  59                  * git-pull, it will notice the misconfiguration because
  60                  * there is no entry in the resulting FETCH_HEAD marked
  61                  * for merging.
  62                  */
  63                 refspec.src = branch->merge[i]->src;
  64                 refspec.dst = NULL;
  65                 refspec.pattern = 0;
  66                 refspec.force = 0;
  67                 get_fetch_map(remote_refs, &refspec, tail, 1);
  68                 for (rm = *old_tail; rm; rm = rm->next)
  69                         rm->merge = 1;
  70         }
  71 }
  72
  73 static struct ref *get_ref_map(struct transport *transport,
  74                                struct refspec *refs, int ref_count, int tags,
  75                                int *autotags)
  76 {
  77         int i;
  78         struct ref *rm;
  79         struct ref *ref_map = NULL;
  80         struct ref **tail = &ref_map;
  81
  82         const struct ref *remote_refs = transport_get_remote_refs(transport);
  83
  84         if (ref_count || tags) {
  85                 for (i = 0; i < ref_count; i++) {
  86                         get_fetch_map(remote_refs, &refs[i], &tail, 0);
  87                         if (refs[i].dst && refs[i].dst[0])
  88                                 *autotags = 1;
  89                 }
  90                 /* Merge everything on the command line, but not --tags */
  91                 for (rm = ref_map; rm; rm = rm->next)
  92                         rm->merge = 1;
  93                 if (tags) {
  94                         struct refspec refspec;
  95                         refspec.src = "refs/tags/";
  96                         refspec.dst = "refs/tags/";
  97                         refspec.pattern = 1;
  98                         refspec.force = 0;
  99                         get_fetch_map(remote_refs, &refspec, &tail, 0);
 100                 }
 101         } else {
 102                 /* Use the defaults */
 103                 struct remote *remote = transport->remote;
 104                 struct branch *branch = branch_get(NULL);
 105                 int has_merge = branch_has_merge_config(branch);
 106                 if (remote && (remote->fetch_refspec_nr || has_merge)) {
 107                         for (i = 0; i < remote->fetch_refspec_nr; i++) {
 108                                 get_fetch_map(remote_refs, &remote->fetch[i], &tail, 0);
 109                                 if (remote->fetch[i].dst &&
 110                                     remote->fetch[i].dst[0])
 111                                         *autotags = 1;
 112                                 if (!i && !has_merge && ref_map &&
 113                                     !remote->fetch[0].pattern)
 114                                         ref_map->merge = 1;
 115                         }
 116                         /*
 117                          * if the remote we're fetching from is the same
 118                          * as given in branch.<name>.remote, we add the
 119                          * ref given in branch.<name>.merge, too.
 120                          */
 121                         if (has_merge &&
 122                             !strcmp(branch->remote_name, remote->name))
 123                                 add_merge_config(&ref_map, remote_refs, branch, &tail);
 124                 } else {
 125                         ref_map = get_remote_ref(remote_refs, "HEAD");
 126                         if (!ref_map)
 127                                 die("Couldn't find remote ref HEAD");
 128                         ref_map->merge = 1;
 129                 }
 130         }
 131         ref_remove_duplicates(ref_map);
 132
 133         return ref_map;
 134 }
 135
 136 static int s_update_ref(const char *action,
 137                         struct ref *ref,
 138                         int check_old)
 139 {
 140         char msg[1024];
 141         char *rla = getenv("GIT_REFLOG_ACTION");
 142         static struct ref_lock *lock;
 143
 144         if (!rla)
 145                 rla = default_rla;
 146         snprintf(msg, sizeof(msg), "%s: %s", rla, action);
 147         lock = lock_any_ref_for_update(ref->name,
 148                                        check_old ? ref->old_sha1 : NULL, 0);
 149         if (!lock)
 150                 return 1;
 151         if (write_ref_sha1(lock, ref->new_sha1, msg) < 0)
 152                 return 1;
 153         return 0;
 154 }
 155
 156 #define SUMMARY_WIDTH (2 * DEFAULT_ABBREV + 3)
 157 #define REFCOL_WIDTH  10
 158
 159 static int update_local_ref(struct ref *ref,
 160                             const char *remote,
 161                             int verbose,
 162                             char *display)
 163 {
 164         struct commit *current = NULL, *updated;
 165         enum object_type type;
 166         struct branch *current_branch = branch_get(NULL);
 167         const char *pretty_ref = ref->name + (
 168                 !prefixcmp(ref->name, "refs/heads/") ? 11 :
 169                 !prefixcmp(ref->name, "refs/tags/") ? 10 :
 170                 !prefixcmp(ref->name, "refs/remotes/") ? 13 :
 171                 0);
 172
 173         *display = 0;
 174         type = sha1_object_info(ref->new_sha1, NULL);
 175         if (type < 0)
 176                 die("object %s not found", sha1_to_hex(ref->new_sha1));
 177
 178         if (!*ref->name) {
 179                 /* Not storing */
 180                 if (verbose)
 181                         sprintf(display, "* branch %s -> FETCH_HEAD", remote);
 182                 return 0;
 183         }
 184
 185         if (!hashcmp(ref->old_sha1, ref->new_sha1)) {
 186                 if (verbose)
 187                         sprintf(display, "= %-*s %-*s -> %s", SUMMARY_WIDTH,
 188                                 "[up to date]", REFCOL_WIDTH, remote,
 189                                 pretty_ref);
 190                 return 0;
 191         }
 192
 193         if (current_branch &&
 194             !strcmp(ref->name, current_branch->name) &&
 195             !(update_head_ok || is_bare_repository()) &&
 196             !is_null_sha1(ref->old_sha1)) {
 197                 /*
 198                  * If this is the head, and it's not okay to update
 199                  * the head, and the old value of the head isn't empty...
 200                  */
 201                 sprintf(display, "! %-*s %-*s -> %s  (can't fetch in current branch)",
 202                         SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
 203                         pretty_ref);
 204                 return 1;
 205         }
 206
 207         if (!is_null_sha1(ref->old_sha1) &&
 208             !prefixcmp(ref->name, "refs/tags/")) {
 209                 sprintf(display, "- %-*s %-*s -> %s",
 210                         SUMMARY_WIDTH, "[tag update]", REFCOL_WIDTH, remote,
 211                         pretty_ref);
 212                 return s_update_ref("updating tag", ref, 0);
 213         }
 214
 215         current = lookup_commit_reference_gently(ref->old_sha1, 1);
 216         updated = lookup_commit_reference_gently(ref->new_sha1, 1);
 217         if (!current || !updated) {
 218                 const char *msg;
 219                 const char *what;
 220                 if (!strncmp(ref->name, "refs/tags/", 10)) {
 221                         msg = "storing tag";
 222                         what = "[new tag]";
 223                 }
 224                 else {
 225                         msg = "storing head";
 226                         what = "[new branch]";
 227                 }
 228
 229                 sprintf(display, "* %-*s %-*s -> %s", SUMMARY_WIDTH, what,
 230                         REFCOL_WIDTH, remote, pretty_ref);
 231                 return s_update_ref(msg, ref, 0);
 232         }
 233
 234         if (in_merge_bases(current, &updated, 1)) {
 235                 char quickref[83];
 236                 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
 237                 strcat(quickref, "..");
 238                 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
 239                 sprintf(display, "  %-*s %-*s -> %s", SUMMARY_WIDTH, quickref,
 240                         REFCOL_WIDTH, remote, pretty_ref);
 241                 return s_update_ref("fast forward", ref, 1);
 242         } else if (force || ref->force) {
 243                 char quickref[84];
 244                 strcpy(quickref, find_unique_abbrev(current->object.sha1, DEFAULT_ABBREV));
 245                 strcat(quickref, "...");
 246                 strcat(quickref, find_unique_abbrev(ref->new_sha1, DEFAULT_ABBREV));
 247                 sprintf(display, "+ %-*s %-*s -> %s  (forced update)",
 248                         SUMMARY_WIDTH, quickref, REFCOL_WIDTH, remote, pretty_ref);
 249                 return s_update_ref("forced-update", ref, 1);
 250         } else {
 251                 sprintf(display, "! %-*s %-*s -> %s  (non fast forward)",
 252                         SUMMARY_WIDTH, "[rejected]", REFCOL_WIDTH, remote,
 253                         pretty_ref);
 254                 return 1;
 255         }
 256 }
 257
 258 static int store_updated_refs(const char *url, struct ref *ref_map)
 259 {
 260         FILE *fp;
 261         struct commit *commit;
 262         int url_len, i, note_len, shown_url = 0;
 263         char note[1024];
 264         const char *what, *kind;
 265         struct ref *rm;
 266         char *filename = git_path("FETCH_HEAD");
 267
 268         fp = fopen(filename, "a");
 269         if (!fp)
 270                 return error("cannot open %s: %s\n", filename, strerror(errno));
 271         for (rm = ref_map; rm; rm = rm->next) {
 272                 struct ref *ref = NULL;
 273
 274                 if (rm->peer_ref) {
 275                         ref = xcalloc(1, sizeof(*ref) + strlen(rm->peer_ref->name) + 1);
 276                         strcpy(ref->name, rm->peer_ref->name);
 277                         hashcpy(ref->old_sha1, rm->peer_ref->old_sha1);
 278                         hashcpy(ref->new_sha1, rm->old_sha1);
 279                         ref->force = rm->peer_ref->force;
 280                 }
 281
 282                 commit = lookup_commit_reference_gently(rm->old_sha1, 1);
 283                 if (!commit)
 284                         rm->merge = 0;
 285
 286                 if (!strcmp(rm->name, "HEAD")) {
 287                         kind = "";
 288                         what = "";
 289                 }
 290                 else if (!prefixcmp(rm->name, "refs/heads/")) {
 291                         kind = "branch";
 292                         what = rm->name + 11;
 293                 }
 294                 else if (!prefixcmp(rm->name, "refs/tags/")) {
 295                         kind = "tag";
 296                         what = rm->name + 10;
 297                 }
 298                 else if (!prefixcmp(rm->name, "refs/remotes/")) {
 299                         kind = "remote branch";
 300                         what = rm->name + 13;
 301                 }
 302                 else {
 303                         kind = "";
 304                         what = rm->name;
 305                 }
 306
 307                 url_len = strlen(url);
 308                 for (i = url_len - 1; url[i] == '/' && 0 <= i; i--)
 309                         ;
 310                 url_len = i + 1;
 311                 if (4 < i && !strncmp(".git", url + i - 3, 4))
 312                         url_len = i - 3;
 313
 314                 note_len = 0;
 315                 if (*what) {
 316                         if (*kind)
 317                                 note_len += sprintf(note + note_len, "%s ",
 318                                                     kind);
 319                         note_len += sprintf(note + note_len, "'%s' of ", what);
 320                 }
 321                 note_len += sprintf(note + note_len, "%.*s", url_len, url);
 322                 fprintf(fp, "%s\t%s\t%s\n",
 323                         sha1_to_hex(commit ? commit->object.sha1 :
 324                                     rm->old_sha1),
 325                         rm->merge ? "" : "not-for-merge",
 326                         note);
 327
 328                 if (ref) {
 329                         update_local_ref(ref, what, verbose, note);
 330                         if (*note) {
 331                                 if (!shown_url) {
 332                                         fprintf(stderr, "From %.*s\n",
 333                                                         url_len, url);
 334                                         shown_url = 1;
 335                                 }
 336                                 fprintf(stderr, " %s\n", note);
 337                         }
 338                 }
 339         }
 340         fclose(fp);
 341         return 0;
 342 }
 343
 344 /*
 345  * We would want to bypass the object transfer altogether if
 346  * everything we are going to fetch already exists and connected
 347  * locally.
 348  *
 349  * The refs we are going to fetch are in to_fetch (nr_heads in
 350  * total).  If running
 351  *
 352  *  $ git-rev-list --objects to_fetch[0] to_fetch[1] ... --not --all
 353  *
 354  * does not error out, that means everything reachable from the
 355  * refs we are going to fetch exists and is connected to some of
 356  * our existing refs.
 357  */
 358 static int quickfetch(struct ref *ref_map)
 359 {
 360         struct child_process revlist;
 361         struct ref *ref;
 362         char **argv;
 363         int i, err;
 364
 365         /*
 366          * If we are deepening a shallow clone we already have these
 367          * objects reachable.  Running rev-list here will return with
 368          * a good (0) exit status and we'll bypass the fetch that we
 369          * really need to perform.  Claiming failure now will ensure
 370          * we perform the network exchange to deepen our history.
 371          */
 372         if (depth)
 373                 return -1;
 374
 375         for (i = 0, ref = ref_map; ref; ref = ref->next)
 376                 i++;
 377         if (!i)
 378                 return 0;
 379
 380         argv = xmalloc(sizeof(*argv) * (i + 6));
 381         i = 0;
 382         argv[i++] = xstrdup("rev-list");
 383         argv[i++] = xstrdup("--quiet");
 384         argv[i++] = xstrdup("--objects");
 385         for (ref = ref_map; ref; ref = ref->next)
 386                 argv[i++] = xstrdup(sha1_to_hex(ref->old_sha1));
 387         argv[i++] = xstrdup("--not");
 388         argv[i++] = xstrdup("--all");
 389         argv[i++] = NULL;
 390
 391         memset(&revlist, 0, sizeof(revlist));
 392         revlist.argv = (const char**)argv;
 393         revlist.git_cmd = 1;
 394         revlist.no_stdin = 1;
 395         revlist.no_stdout = 1;
 396         revlist.no_stderr = 1;
 397         err = run_command(&revlist);
 398
 399         for (i = 0; argv[i]; i++)
 400                 free(argv[i]);
 401         free(argv);
 402         return err;
 403 }
 404
 405 static int fetch_refs(struct transport *transport, struct ref *ref_map)
 406 {
 407         int ret = quickfetch(ref_map);
 408         if (ret)
 409                 ret = transport_fetch_refs(transport, ref_map);
 410         if (!ret)
 411                 ret |= store_updated_refs(transport->url, ref_map);
 412         transport_unlock_pack(transport);
 413         return ret;
 414 }
 415
 416 static int add_existing(const char *refname, const unsigned char *sha1,
 417                         int flag, void *cbdata)
 418 {
 419         struct path_list *list = (struct path_list *)cbdata;
 420         path_list_insert(refname, list);
 421         return 0;
 422 }
 423
 424 static struct ref *find_non_local_tags(struct transport *transport,
 425                                        struct ref *fetch_map)
 426 {
 427         static struct path_list existing_refs = { NULL, 0, 0, 0 };
 428         struct path_list new_refs = { NULL, 0, 0, 1 };
 429         char *ref_name;
 430         int ref_name_len;
 431         const unsigned char *ref_sha1;
 432         const struct ref *tag_ref;
 433         struct ref *rm = NULL;
 434         struct ref *ref_map = NULL;
 435         struct ref **tail = &ref_map;
 436         const struct ref *ref;
 437
 438         for_each_ref(add_existing, &existing_refs);
 439         for (ref = transport_get_remote_refs(transport); ref; ref = ref->next) {
 440                 if (prefixcmp(ref->name, "refs/tags"))
 441                         continue;
 442
 443                 ref_name = xstrdup(ref->name);
 444                 ref_name_len = strlen(ref_name);
 445                 ref_sha1 = ref->old_sha1;
 446
 447                 if (!strcmp(ref_name + ref_name_len - 3, "^{}")) {
 448                         ref_name[ref_name_len - 3] = 0;
 449                         tag_ref = transport_get_remote_refs(transport);
 450                         while (tag_ref) {
 451                                 if (!strcmp(tag_ref->name, ref_name)) {
 452                                         ref_sha1 = tag_ref->old_sha1;
 453                                         break;
 454                                 }
 455                                 tag_ref = tag_ref->next;
 456                         }
 457                 }
 458
 459                 if (!path_list_has_path(&existing_refs, ref_name) &&
 460                     !path_list_has_path(&new_refs, ref_name) &&
 461                     has_sha1_file(ref->old_sha1)) {
 462                         path_list_insert(ref_name, &new_refs);
 463
 464                         rm = alloc_ref(strlen(ref_name) + 1);
 465                         strcpy(rm->name, ref_name);
 466                         rm->peer_ref = alloc_ref(strlen(ref_name) + 1);
 467                         strcpy(rm->peer_ref->name, ref_name);
 468                         hashcpy(rm->old_sha1, ref_sha1);
 469
 470                         *tail = rm;
 471                         tail = &rm->next;
 472                 }
 473                 free(ref_name);
 474         }
 475
 476         return ref_map;
 477 }
 478
 479 static int do_fetch(struct transport *transport,
 480                     struct refspec *refs, int ref_count)
 481 {
 482         struct ref *ref_map, *fetch_map;
 483         struct ref *rm;
 484         int autotags = (transport->remote->fetch_tags == 1);
 485         if (transport->remote->fetch_tags == 2 && !no_tags)
 486                 tags = 1;
 487         if (transport->remote->fetch_tags == -1)
 488                 no_tags = 1;
 489
 490         if (!transport->get_refs_list || !transport->fetch)
 491                 die("Don't know how to fetch from %s", transport->url);
 492
 493         /* if not appending, truncate FETCH_HEAD */
 494         if (!append) {
 495                 char *filename = git_path("FETCH_HEAD");
 496                 FILE *fp = fopen(filename, "w");
 497                 if (!fp)
 498                         return error("cannot open %s: %s\n", filename, strerror(errno));
 499                 fclose(fp);
 500         }
 501
 502         ref_map = get_ref_map(transport, refs, ref_count, tags, &autotags);
 503
 504         for (rm = ref_map; rm; rm = rm->next) {
 505                 if (rm->peer_ref)
 506                         read_ref(rm->peer_ref->name, rm->peer_ref->old_sha1);
 507         }
 508
 509         if (fetch_refs(transport, ref_map)) {
 510                 free_refs(ref_map);
 511                 return 1;
 512         }
 513
 514         fetch_map = ref_map;
 515
 516         /* if neither --no-tags nor --tags was specified, do automated tag
 517          * following ... */
 518         if (!(tags || no_tags) && autotags) {
 519                 ref_map = find_non_local_tags(transport, fetch_map);
 520                 if (ref_map) {
 521                         transport_set_option(transport, TRANS_OPT_DEPTH, "0");
 522                         fetch_refs(transport, ref_map);
 523                 }
 524                 free_refs(ref_map);
 525         }
 526
 527         free_refs(fetch_map);
 528
 529         return 0;
 530 }
 531
 532 static void set_option(const char *name, const char *value)
 533 {
 534         int r = transport_set_option(transport, name, value);
 535         if (r < 0)
 536                 die("Option \"%s\" value \"%s\" is not valid for %s\n",
 537                         name, value, transport->url);
 538         if (r > 0)
 539                 warning("Option \"%s\" is ignored for %s\n",
 540                         name, transport->url);
 541 }
 542
 543 int cmd_fetch(int argc, const char **argv, const char *prefix)
 544 {
 545         struct remote *remote;
 546         int i, j, rla_offset;
 547         static const char **refs = NULL;
 548         int ref_nr = 0;
 549         int cmd_len = 0;
 550         const char *upload_pack = NULL;
 551         int keep = 0;
 552
 553         for (i = 1; i < argc; i++) {
 554                 const char *arg = argv[i];
 555                 cmd_len += strlen(arg);
 556
 557                 if (arg[0] != '-')
 558                         break;
 559                 if (!strcmp(arg, "--append") || !strcmp(arg, "-a")) {
 560                         append = 1;
 561                         continue;
 562                 }
 563                 if (!prefixcmp(arg, "--upload-pack=")) {
 564                         upload_pack = arg + 14;
 565                         continue;
 566                 }
 567                 if (!strcmp(arg, "--upload-pack")) {
 568                         i++;
 569                         if (i == argc)
 570                                 usage(fetch_usage);
 571                         upload_pack = argv[i];
 572                         continue;
 573                 }
 574                 if (!strcmp(arg, "--force") || !strcmp(arg, "-f")) {
 575                         force = 1;
 576                         continue;
 577                 }
 578                 if (!strcmp(arg, "--no-tags")) {
 579                         no_tags = 1;
 580                         continue;
 581                 }
 582                 if (!strcmp(arg, "--tags") || !strcmp(arg, "-t")) {
 583                         tags = 1;
 584                         continue;
 585                 }
 586                 if (!strcmp(arg, "--keep") || !strcmp(arg, "-k")) {
 587                         keep = 1;
 588                         continue;
 589                 }
 590                 if (!strcmp(arg, "--update-head-ok") || !strcmp(arg, "-u")) {
 591                         update_head_ok = 1;
 592                         continue;
 593                 }
 594                 if (!prefixcmp(arg, "--depth=")) {
 595                         depth = arg + 8;
 596                         continue;
 597                 }
 598                 if (!strcmp(arg, "--depth")) {
 599                         i++;
 600                         if (i == argc)
 601                                 usage(fetch_usage);
 602                         depth = argv[i];
 603                         continue;
 604                 }
 605                 if (!strcmp(arg, "--quiet") || !strcmp(arg, "-q")) {
 606                         quiet = 1;
 607                         continue;
 608                 }
 609                 if (!strcmp(arg, "--verbose") || !strcmp(arg, "-v")) {
 610                         verbose++;
 611                         continue;
 612                 }
 613                 usage(fetch_usage);
 614         }
 615
 616         for (j = i; j < argc; j++)
 617                 cmd_len += strlen(argv[j]);
 618
 619         default_rla = xmalloc(cmd_len + 5 + argc + 1);
 620         sprintf(default_rla, "fetch");
 621         rla_offset = strlen(default_rla);
 622         for (j = 1; j < argc; j++) {
 623                 sprintf(default_rla + rla_offset, " %s", argv[j]);
 624                 rla_offset += strlen(argv[j]) + 1;
 625         }
 626
 627         if (i == argc)
 628                 remote = remote_get(NULL);
 629         else
 630                 remote = remote_get(argv[i++]);
 631
 632         transport = transport_get(remote, remote->url[0]);
 633         if (verbose >= 2)
 634                 transport->verbose = 1;
 635         if (quiet)
 636                 transport->verbose = -1;
 637         if (upload_pack)
 638                 set_option(TRANS_OPT_UPLOADPACK, upload_pack);
 639         if (keep)
 640                 set_option(TRANS_OPT_KEEP, "yes");
 641         if (depth)
 642                 set_option(TRANS_OPT_DEPTH, depth);
 643
 644         if (!transport->url)
 645                 die("Where do you want to fetch from today?");
 646
 647         if (i < argc) {
 648                 int j = 0;
 649                 refs = xcalloc(argc - i + 1, sizeof(const char *));
 650                 while (i < argc) {
 651                         if (!strcmp(argv[i], "tag")) {
 652                                 char *ref;
 653                                 i++;
 654                                 ref = xmalloc(strlen(argv[i]) * 2 + 22);
 655                                 strcpy(ref, "refs/tags/");
 656                                 strcat(ref, argv[i]);
 657                                 strcat(ref, ":refs/tags/");
 658                                 strcat(ref, argv[i]);
 659                                 refs[j++] = ref;
 660                         } else
 661                                 refs[j++] = argv[i];
 662                         i++;
 663                 }
 664                 refs[j] = NULL;
 665                 ref_nr = j;
 666         }
 667
 668         signal(SIGINT, unlock_pack_on_signal);
 669         atexit(unlock_pack);
 670         return do_fetch(transport, parse_ref_spec(ref_nr, refs), ref_nr);
 671 }