builtin-fetch-pack.c

   1 #include "cache.h"
   2 #include "refs.h"
   3 #include "pkt-line.h"
   4 #include "commit.h"
   5 #include "tag.h"
   6 #include "exec_cmd.h"
   7 #include "pack.h"
   8 #include "sideband.h"
   9 #include "fetch-pack.h"
  10 #include "remote.h"
  11 #include "run-command.h"
  12
  13 static int transfer_unpack_limit = -1;
  14 static int fetch_unpack_limit = -1;
  15 static int unpack_limit = 100;
  16 static struct fetch_pack_args args = {
  17         /* .uploadpack = */ "git-upload-pack",
  18 };
  19
  20 static const char fetch_pack_usage[] =
  21 "git-fetch-pack [--all] [--quiet|-q] [--keep|-k] [--thin] [--include-tag] [--upload-pack=<git-upload-pack>] [--depth=<n>] [--no-progress] [-v] [<host>:]<directory> [<refs>...]";
  22
  23 #define COMPLETE        (1U << 0)
  24 #define COMMON          (1U << 1)
  25 #define COMMON_REF      (1U << 2)
  26 #define SEEN            (1U << 3)
  27 #define POPPED          (1U << 4)
  28
  29 /*
  30  * After sending this many "have"s if we do not get any new ACK , we
  31  * give up traversing our history.
  32  */
  33 #define MAX_IN_VAIN 256
  34
  35 static struct commit_list *rev_list;
  36 static int non_common_revs, multi_ack, use_sideband;
  37
  38 static void rev_list_push(struct commit *commit, int mark)
  39 {
  40         if (!(commit->object.flags & mark)) {
  41                 commit->object.flags |= mark;
  42
  43                 if (!(commit->object.parsed))
  44                         if (parse_commit(commit))
  45                                 return;
  46
  47                 insert_by_date(commit, &rev_list);
  48
  49                 if (!(commit->object.flags & COMMON))
  50                         non_common_revs++;
  51         }
  52 }
  53
  54 static int rev_list_insert_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  55 {
  56         struct object *o = deref_tag(parse_object(sha1), path, 0);
  57
  58         if (o && o->type == OBJ_COMMIT)
  59                 rev_list_push((struct commit *)o, SEEN);
  60
  61         return 0;
  62 }
  63
  64 /*
  65    This function marks a rev and its ancestors as common.
  66    In some cases, it is desirable to mark only the ancestors (for example
  67    when only the server does not yet know that they are common).
  68 */
  69
  70 static void mark_common(struct commit *commit,
  71                 int ancestors_only, int dont_parse)
  72 {
  73         if (commit != NULL && !(commit->object.flags & COMMON)) {
  74                 struct object *o = (struct object *)commit;
  75
  76                 if (!ancestors_only)
  77                         o->flags |= COMMON;
  78
  79                 if (!(o->flags & SEEN))
  80                         rev_list_push(commit, SEEN);
  81                 else {
  82                         struct commit_list *parents;
  83
  84                         if (!ancestors_only && !(o->flags & POPPED))
  85                                 non_common_revs--;
  86                         if (!o->parsed && !dont_parse)
  87                                 if (parse_commit(commit))
  88                                         return;
  89
  90                         for (parents = commit->parents;
  91                                         parents;
  92                                         parents = parents->next)
  93                                 mark_common(parents->item, 0, dont_parse);
  94                 }
  95         }
  96 }
  97
  98 /*
  99   Get the next rev to send, ignoring the common.
 100 */
 101
 102 static const unsigned char* get_rev(void)
 103 {
 104         struct commit *commit = NULL;
 105
 106         while (commit == NULL) {
 107                 unsigned int mark;
 108                 struct commit_list *parents = NULL;
 109
 110                 if (rev_list == NULL || non_common_revs == 0)
 111                         return NULL;
 112
 113                 commit = rev_list->item;
 114                 if (!(commit->object.parsed))
 115                         if (!parse_commit(commit))
 116                                 parents = commit->parents;
 117
 118                 commit->object.flags |= POPPED;
 119                 if (!(commit->object.flags & COMMON))
 120                         non_common_revs--;
 121
 122                 if (commit->object.flags & COMMON) {
 123                         /* do not send "have", and ignore ancestors */
 124                         commit = NULL;
 125                         mark = COMMON | SEEN;
 126                 } else if (commit->object.flags & COMMON_REF)
 127                         /* send "have", and ignore ancestors */
 128                         mark = COMMON | SEEN;
 129                 else
 130                         /* send "have", also for its ancestors */
 131                         mark = SEEN;
 132
 133                 while (parents) {
 134                         if (!(parents->item->object.flags & SEEN))
 135                                 rev_list_push(parents->item, mark);
 136                         if (mark & COMMON)
 137                                 mark_common(parents->item, 1, 0);
 138                         parents = parents->next;
 139                 }
 140
 141                 rev_list = rev_list->next;
 142         }
 143
 144         return commit->object.sha1;
 145 }
 146
 147 static int find_common(int fd[2], unsigned char *result_sha1,
 148                        struct ref *refs)
 149 {
 150         int fetching;
 151         int count = 0, flushes = 0, retval;
 152         const unsigned char *sha1;
 153         unsigned in_vain = 0;
 154         int got_continue = 0;
 155
 156         for_each_ref(rev_list_insert_ref, NULL);
 157
 158         fetching = 0;
 159         for ( ; refs ; refs = refs->next) {
 160                 unsigned char *remote = refs->old_sha1;
 161                 struct object *o;
 162
 163                 /*
 164                  * If that object is complete (i.e. it is an ancestor of a
 165                  * local ref), we tell them we have it but do not have to
 166                  * tell them about its ancestors, which they already know
 167                  * about.
 168                  *
 169                  * We use lookup_object here because we are only
 170                  * interested in the case we *know* the object is
 171                  * reachable and we have already scanned it.
 172                  */
 173                 if (((o = lookup_object(remote)) != NULL) &&
 174                                 (o->flags & COMPLETE)) {
 175                         continue;
 176                 }
 177
 178                 if (!fetching)
 179                         packet_write(fd[1], "want %s%s%s%s%s%s%s%s\n",
 180                                      sha1_to_hex(remote),
 181                                      (multi_ack ? " multi_ack" : ""),
 182                                      (use_sideband == 2 ? " side-band-64k" : ""),
 183                                      (use_sideband == 1 ? " side-band" : ""),
 184                                      (args.use_thin_pack ? " thin-pack" : ""),
 185                                      (args.no_progress ? " no-progress" : ""),
 186                                      (args.include_tag ? " include-tag" : ""),
 187                                      " ofs-delta");
 188                 else
 189                         packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
 190                 fetching++;
 191         }
 192         if (is_repository_shallow())
 193                 write_shallow_commits(fd[1], 1);
 194         if (args.depth > 0)
 195                 packet_write(fd[1], "deepen %d", args.depth);
 196         packet_flush(fd[1]);
 197         if (!fetching)
 198                 return 1;
 199
 200         if (args.depth > 0) {
 201                 char line[1024];
 202                 unsigned char sha1[20];
 203                 int len;
 204
 205                 while ((len = packet_read_line(fd[0], line, sizeof(line)))) {
 206                         if (!prefixcmp(line, "shallow ")) {
 207                                 if (get_sha1_hex(line + 8, sha1))
 208                                         die("invalid shallow line: %s", line);
 209                                 register_shallow(sha1);
 210                                 continue;
 211                         }
 212                         if (!prefixcmp(line, "unshallow ")) {
 213                                 if (get_sha1_hex(line + 10, sha1))
 214                                         die("invalid unshallow line: %s", line);
 215                                 if (!lookup_object(sha1))
 216                                         die("object not found: %s", line);
 217                                 /* make sure that it is parsed as shallow */
 218                                 if (!parse_object(sha1))
 219                                         die("error in object: %s", line);
 220                                 if (unregister_shallow(sha1))
 221                                         die("no shallow found: %s", line);
 222                                 continue;
 223                         }
 224                         die("expected shallow/unshallow, got %s", line);
 225                 }
 226         }
 227
 228         flushes = 0;
 229         retval = -1;
 230         while ((sha1 = get_rev())) {
 231                 packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
 232                 if (args.verbose)
 233                         fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
 234                 in_vain++;
 235                 if (!(31 & ++count)) {
 236                         int ack;
 237
 238                         packet_flush(fd[1]);
 239                         flushes++;
 240
 241                         /*
 242                          * We keep one window "ahead" of the other side, and
 243                          * will wait for an ACK only on the next one
 244                          */
 245                         if (count == 32)
 246                                 continue;
 247
 248                         do {
 249                                 ack = get_ack(fd[0], result_sha1);
 250                                 if (args.verbose && ack)
 251                                         fprintf(stderr, "got ack %d %s\n", ack,
 252                                                         sha1_to_hex(result_sha1));
 253                                 if (ack == 1) {
 254                                         flushes = 0;
 255                                         multi_ack = 0;
 256                                         retval = 0;
 257                                         goto done;
 258                                 } else if (ack == 2) {
 259                                         struct commit *commit =
 260                                                 lookup_commit(result_sha1);
 261                                         mark_common(commit, 0, 1);
 262                                         retval = 0;
 263                                         in_vain = 0;
 264                                         got_continue = 1;
 265                                 }
 266                         } while (ack);
 267                         flushes--;
 268                         if (got_continue && MAX_IN_VAIN < in_vain) {
 269                                 if (args.verbose)
 270                                         fprintf(stderr, "giving up\n");
 271                                 break; /* give up */
 272                         }
 273                 }
 274         }
 275 done:
 276         packet_write(fd[1], "done\n");
 277         if (args.verbose)
 278                 fprintf(stderr, "done\n");
 279         if (retval != 0) {
 280                 multi_ack = 0;
 281                 flushes++;
 282         }
 283         while (flushes || multi_ack) {
 284                 int ack = get_ack(fd[0], result_sha1);
 285                 if (ack) {
 286                         if (args.verbose)
 287                                 fprintf(stderr, "got ack (%d) %s\n", ack,
 288                                         sha1_to_hex(result_sha1));
 289                         if (ack == 1)
 290                                 return 0;
 291                         multi_ack = 1;
 292                         continue;
 293                 }
 294                 flushes--;
 295         }
 296         return retval;
 297 }
 298
 299 static struct commit_list *complete;
 300
 301 static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 302 {
 303         struct object *o = parse_object(sha1);
 304
 305         while (o && o->type == OBJ_TAG) {
 306                 struct tag *t = (struct tag *) o;
 307                 if (!t->tagged)
 308                         break; /* broken repository */
 309                 o->flags |= COMPLETE;
 310                 o = parse_object(t->tagged->sha1);
 311         }
 312         if (o && o->type == OBJ_COMMIT) {
 313                 struct commit *commit = (struct commit *)o;
 314                 commit->object.flags |= COMPLETE;
 315                 insert_by_date(commit, &complete);
 316         }
 317         return 0;
 318 }
 319
 320 static void mark_recent_complete_commits(unsigned long cutoff)
 321 {
 322         while (complete && cutoff <= complete->item->date) {
 323                 if (args.verbose)
 324                         fprintf(stderr, "Marking %s as complete\n",
 325                                 sha1_to_hex(complete->item->object.sha1));
 326                 pop_most_recent_commit(&complete, COMPLETE);
 327         }
 328 }
 329
 330 static void filter_refs(struct ref **refs, int nr_match, char **match)
 331 {
 332         struct ref **return_refs;
 333         struct ref *newlist = NULL;
 334         struct ref **newtail = &newlist;
 335         struct ref *ref, *next;
 336         struct ref *fastarray[32];
 337
 338         if (nr_match && !args.fetch_all) {
 339                 if (ARRAY_SIZE(fastarray) < nr_match)
 340                         return_refs = xcalloc(nr_match, sizeof(struct ref *));
 341                 else {
 342                         return_refs = fastarray;
 343                         memset(return_refs, 0, sizeof(struct ref *) * nr_match);
 344                 }
 345         }
 346         else
 347                 return_refs = NULL;
 348
 349         for (ref = *refs; ref; ref = next) {
 350                 next = ref->next;
 351                 if (!memcmp(ref->name, "refs/", 5) &&
 352                     check_ref_format(ref->name + 5))
 353                         ; /* trash */
 354                 else if (args.fetch_all &&
 355                          (!args.depth || prefixcmp(ref->name, "refs/tags/") )) {
 356                         *newtail = ref;
 357                         ref->next = NULL;
 358                         newtail = &ref->next;
 359                         continue;
 360                 }
 361                 else {
 362                         int order = path_match(ref->name, nr_match, match);
 363                         if (order) {
 364                                 return_refs[order-1] = ref;
 365                                 continue; /* we will link it later */
 366                         }
 367                 }
 368                 free(ref);
 369         }
 370
 371         if (!args.fetch_all) {
 372                 int i;
 373                 for (i = 0; i < nr_match; i++) {
 374                         ref = return_refs[i];
 375                         if (ref) {
 376                                 *newtail = ref;
 377                                 ref->next = NULL;
 378                                 newtail = &ref->next;
 379                         }
 380                 }
 381                 if (return_refs != fastarray)
 382                         free(return_refs);
 383         }
 384         *refs = newlist;
 385 }
 386
 387 static int everything_local(struct ref **refs, int nr_match, char **match)
 388 {
 389         struct ref *ref;
 390         int retval;
 391         unsigned long cutoff = 0;
 392
 393         save_commit_buffer = 0;
 394
 395         for (ref = *refs; ref; ref = ref->next) {
 396                 struct object *o;
 397
 398                 o = parse_object(ref->old_sha1);
 399                 if (!o)
 400                         continue;
 401
 402                 /* We already have it -- which may mean that we were
 403                  * in sync with the other side at some time after
 404                  * that (it is OK if we guess wrong here).
 405                  */
 406                 if (o->type == OBJ_COMMIT) {
 407                         struct commit *commit = (struct commit *)o;
 408                         if (!cutoff || cutoff < commit->date)
 409                                 cutoff = commit->date;
 410                 }
 411         }
 412
 413         if (!args.depth) {
 414                 for_each_ref(mark_complete, NULL);
 415                 if (cutoff)
 416                         mark_recent_complete_commits(cutoff);
 417         }
 418
 419         /*
 420          * Mark all complete remote refs as common refs.
 421          * Don't mark them common yet; the server has to be told so first.
 422          */
 423         for (ref = *refs; ref; ref = ref->next) {
 424                 struct object *o = deref_tag(lookup_object(ref->old_sha1),
 425                                              NULL, 0);
 426
 427                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 428                         continue;
 429
 430                 if (!(o->flags & SEEN)) {
 431                         rev_list_push((struct commit *)o, COMMON_REF | SEEN);
 432
 433                         mark_common((struct commit *)o, 1, 1);
 434                 }
 435         }
 436
 437         filter_refs(refs, nr_match, match);
 438
 439         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 440                 const unsigned char *remote = ref->old_sha1;
 441                 unsigned char local[20];
 442                 struct object *o;
 443
 444                 o = lookup_object(remote);
 445                 if (!o || !(o->flags & COMPLETE)) {
 446                         retval = 0;
 447                         if (!args.verbose)
 448                                 continue;
 449                         fprintf(stderr,
 450                                 "want %s (%s)\n", sha1_to_hex(remote),
 451                                 ref->name);
 452                         continue;
 453                 }
 454
 455                 hashcpy(ref->new_sha1, local);
 456                 if (!args.verbose)
 457                         continue;
 458                 fprintf(stderr,
 459                         "already have %s (%s)\n", sha1_to_hex(remote),
 460                         ref->name);
 461         }
 462         return retval;
 463 }
 464
 465 static int sideband_demux(int fd, void *data)
 466 {
 467         int *xd = data;
 468
 469         return recv_sideband("fetch-pack", xd[0], fd, 2);
 470 }
 471
 472 static int get_pack(int xd[2], char **pack_lockfile)
 473 {
 474         struct async demux;
 475         const char *argv[20];
 476         char keep_arg[256];
 477         char hdr_arg[256];
 478         const char **av;
 479         int do_keep = args.keep_pack;
 480         struct child_process cmd;
 481
 482         memset(&demux, 0, sizeof(demux));
 483         if (use_sideband) {
 484                 /* xd[] is talking with upload-pack; subprocess reads from
 485                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 486                  * through demux->out.
 487                  */
 488                 demux.proc = sideband_demux;
 489                 demux.data = xd;
 490                 if (start_async(&demux))
 491                         die("fetch-pack: unable to fork off sideband"
 492                             " demultiplexer");
 493         }
 494         else
 495                 demux.out = xd[0];
 496
 497         memset(&cmd, 0, sizeof(cmd));
 498         cmd.argv = argv;
 499         av = argv;
 500         *hdr_arg = 0;
 501         if (!args.keep_pack && unpack_limit) {
 502                 struct pack_header header;
 503
 504                 if (read_pack_header(demux.out, &header))
 505                         die("protocol error: bad pack header");
 506                 snprintf(hdr_arg, sizeof(hdr_arg), "--pack_header=%u,%u",
 507                          ntohl(header.hdr_version), ntohl(header.hdr_entries));
 508                 if (ntohl(header.hdr_entries) < unpack_limit)
 509                         do_keep = 0;
 510                 else
 511                         do_keep = 1;
 512         }
 513
 514         if (do_keep) {
 515                 if (pack_lockfile)
 516                         cmd.out = -1;
 517                 *av++ = "index-pack";
 518                 *av++ = "--stdin";
 519                 if (!args.quiet && !args.no_progress)
 520                         *av++ = "-v";
 521                 if (args.use_thin_pack)
 522                         *av++ = "--fix-thin";
 523                 if (args.lock_pack || unpack_limit) {
 524                         int s = sprintf(keep_arg,
 525                                         "--keep=fetch-pack %d on ", getpid());
 526                         if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 527                                 strcpy(keep_arg + s, "localhost");
 528                         *av++ = keep_arg;
 529                 }
 530         }
 531         else {
 532                 *av++ = "unpack-objects";
 533                 if (args.quiet)
 534                         *av++ = "-q";
 535         }
 536         if (*hdr_arg)
 537                 *av++ = hdr_arg;
 538         *av++ = NULL;
 539
 540         cmd.in = demux.out;
 541         cmd.git_cmd = 1;
 542         if (start_command(&cmd))
 543                 die("fetch-pack: unable to fork off %s", argv[0]);
 544         if (do_keep && pack_lockfile) {
 545                 *pack_lockfile = index_pack_lockfile(cmd.out);
 546                 close(cmd.out);
 547         }
 548
 549         if (finish_command(&cmd))
 550                 die("%s failed", argv[0]);
 551         if (use_sideband && finish_async(&demux))
 552                 die("error in sideband demultiplexer");
 553         return 0;
 554 }
 555
 556 static struct ref *do_fetch_pack(int fd[2],
 557                 const struct ref *orig_ref,
 558                 int nr_match,
 559                 char **match,
 560                 char **pack_lockfile)
 561 {
 562         struct ref *ref = copy_ref_list(orig_ref);
 563         unsigned char sha1[20];
 564
 565         if (is_repository_shallow() && !server_supports("shallow"))
 566                 die("Server does not support shallow clients");
 567         if (server_supports("multi_ack")) {
 568                 if (args.verbose)
 569                         fprintf(stderr, "Server supports multi_ack\n");
 570                 multi_ack = 1;
 571         }
 572         if (server_supports("side-band-64k")) {
 573                 if (args.verbose)
 574                         fprintf(stderr, "Server supports side-band-64k\n");
 575                 use_sideband = 2;
 576         }
 577         else if (server_supports("side-band")) {
 578                 if (args.verbose)
 579                         fprintf(stderr, "Server supports side-band\n");
 580                 use_sideband = 1;
 581         }
 582         if (everything_local(&ref, nr_match, match)) {
 583                 packet_flush(fd[1]);
 584                 goto all_done;
 585         }
 586         if (find_common(fd, sha1, ref) < 0)
 587                 if (!args.keep_pack)
 588                         /* When cloning, it is not unusual to have
 589                          * no common commit.
 590                          */
 591                         fprintf(stderr, "warning: no common commits\n");
 592
 593         if (get_pack(fd, pack_lockfile))
 594                 die("git-fetch-pack: fetch failed.");
 595
 596  all_done:
 597         return ref;
 598 }
 599
 600 static int remove_duplicates(int nr_heads, char **heads)
 601 {
 602         int src, dst;
 603
 604         for (src = dst = 0; src < nr_heads; src++) {
 605                 /* If heads[src] is different from any of
 606                  * heads[0..dst], push it in.
 607                  */
 608                 int i;
 609                 for (i = 0; i < dst; i++) {
 610                         if (!strcmp(heads[i], heads[src]))
 611                                 break;
 612                 }
 613                 if (i < dst)
 614                         continue;
 615                 if (src != dst)
 616                         heads[dst] = heads[src];
 617                 dst++;
 618         }
 619         return dst;
 620 }
 621
 622 static int fetch_pack_config(const char *var, const char *value)
 623 {
 624         if (strcmp(var, "fetch.unpacklimit") == 0) {
 625                 fetch_unpack_limit = git_config_int(var, value);
 626                 return 0;
 627         }
 628
 629         if (strcmp(var, "transfer.unpacklimit") == 0) {
 630                 transfer_unpack_limit = git_config_int(var, value);
 631                 return 0;
 632         }
 633
 634         return git_default_config(var, value);
 635 }
 636
 637 static struct lock_file lock;
 638
 639 static void fetch_pack_setup(void)
 640 {
 641         static int did_setup;
 642         if (did_setup)
 643                 return;
 644         git_config(fetch_pack_config);
 645         if (0 <= transfer_unpack_limit)
 646                 unpack_limit = transfer_unpack_limit;
 647         else if (0 <= fetch_unpack_limit)
 648                 unpack_limit = fetch_unpack_limit;
 649         did_setup = 1;
 650 }
 651
 652 int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 653 {
 654         int i, ret, nr_heads;
 655         struct ref *ref = NULL;
 656         char *dest = NULL, **heads;
 657         int fd[2];
 658         struct child_process *conn;
 659
 660         nr_heads = 0;
 661         heads = NULL;
 662         for (i = 1; i < argc; i++) {
 663                 const char *arg = argv[i];
 664
 665                 if (*arg == '-') {
 666                         if (!prefixcmp(arg, "--upload-pack=")) {
 667                                 args.uploadpack = arg + 14;
 668                                 continue;
 669                         }
 670                         if (!prefixcmp(arg, "--exec=")) {
 671                                 args.uploadpack = arg + 7;
 672                                 continue;
 673                         }
 674                         if (!strcmp("--quiet", arg) || !strcmp("-q", arg)) {
 675                                 args.quiet = 1;
 676                                 continue;
 677                         }
 678                         if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
 679                                 args.lock_pack = args.keep_pack;
 680                                 args.keep_pack = 1;
 681                                 continue;
 682                         }
 683                         if (!strcmp("--thin", arg)) {
 684                                 args.use_thin_pack = 1;
 685                                 continue;
 686                         }
 687                         if (!strcmp("--include-tag", arg)) {
 688                                 args.include_tag = 1;
 689                                 continue;
 690                         }
 691                         if (!strcmp("--all", arg)) {
 692                                 args.fetch_all = 1;
 693                                 continue;
 694                         }
 695                         if (!strcmp("-v", arg)) {
 696                                 args.verbose = 1;
 697                                 continue;
 698                         }
 699                         if (!prefixcmp(arg, "--depth=")) {
 700                                 args.depth = strtol(arg + 8, NULL, 0);
 701                                 continue;
 702                         }
 703                         if (!strcmp("--no-progress", arg)) {
 704                                 args.no_progress = 1;
 705                                 continue;
 706                         }
 707                         usage(fetch_pack_usage);
 708                 }
 709                 dest = (char *)arg;
 710                 heads = (char **)(argv + i + 1);
 711                 nr_heads = argc - i - 1;
 712                 break;
 713         }
 714         if (!dest)
 715                 usage(fetch_pack_usage);
 716
 717         conn = git_connect(fd, (char *)dest, args.uploadpack,
 718                            args.verbose ? CONNECT_VERBOSE : 0);
 719         if (conn) {
 720                 get_remote_heads(fd[0], &ref, 0, NULL, 0);
 721
 722                 ref = fetch_pack(&args, fd, conn, ref, dest, nr_heads, heads, NULL);
 723                 close(fd[0]);
 724                 close(fd[1]);
 725                 if (finish_connect(conn))
 726                         ref = NULL;
 727         } else {
 728                 ref = NULL;
 729         }
 730         ret = !ref;
 731
 732         if (!ret && nr_heads) {
 733                 /* If the heads to pull were given, we should have
 734                  * consumed all of them by matching the remote.
 735                  * Otherwise, 'git-fetch remote no-such-ref' would
 736                  * silently succeed without issuing an error.
 737                  */
 738                 for (i = 0; i < nr_heads; i++)
 739                         if (heads[i] && heads[i][0]) {
 740                                 error("no such remote ref %s", heads[i]);
 741                                 ret = 1;
 742                         }
 743         }
 744         while (ref) {
 745                 printf("%s %s\n",
 746                        sha1_to_hex(ref->old_sha1), ref->name);
 747                 ref = ref->next;
 748         }
 749
 750         return ret;
 751 }
 752
 753 struct ref *fetch_pack(struct fetch_pack_args *my_args,
 754                        int fd[], struct child_process *conn,
 755                        const struct ref *ref,
 756                 const char *dest,
 757                 int nr_heads,
 758                 char **heads,
 759                 char **pack_lockfile)
 760 {
 761         struct stat st;
 762         struct ref *ref_cpy;
 763
 764         fetch_pack_setup();
 765         memcpy(&args, my_args, sizeof(args));
 766         if (args.depth > 0) {
 767                 if (stat(git_path("shallow"), &st))
 768                         st.st_mtime = 0;
 769         }
 770
 771         if (heads && nr_heads)
 772                 nr_heads = remove_duplicates(nr_heads, heads);
 773         if (!ref) {
 774                 packet_flush(fd[1]);
 775                 die("no matching remote head");
 776         }
 777         ref_cpy = do_fetch_pack(fd, ref, nr_heads, heads, pack_lockfile);
 778
 779         if (args.depth > 0) {
 780                 struct cache_time mtime;
 781                 char *shallow = git_path("shallow");
 782                 int fd;
 783
 784                 mtime.sec = st.st_mtime;
 785 #ifdef USE_NSEC
 786                 mtime.usec = st.st_mtim.usec;
 787 #endif
 788                 if (stat(shallow, &st)) {
 789                         if (mtime.sec)
 790                                 die("shallow file was removed during fetch");
 791                 } else if (st.st_mtime != mtime.sec
 792 #ifdef USE_NSEC
 793                                 || st.st_mtim.usec != mtime.usec
 794 #endif
 795                           )
 796                         die("shallow file was changed during fetch");
 797
 798                 fd = hold_lock_file_for_update(&lock, shallow, 1);
 799                 if (!write_shallow_commits(fd, 0)) {
 800                         unlink(shallow);
 801                         rollback_lock_file(&lock);
 802                 } else {
 803                         commit_lock_file(&lock);
 804                 }
 805         }
 806
 807         return ref_cpy;
 808 }