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
  10 static int keep_pack;
  11 static int transfer_unpack_limit = -1;
  12 static int fetch_unpack_limit = -1;
  13 static int unpack_limit = 100;
  14 static int quiet;
  15 static int verbose;
  16 static int fetch_all;
  17 static int depth;
  18 static int no_progress;
  19 static const char fetch_pack_usage[] =
  20 "git-fetch-pack [--all] [--quiet|-q] [--keep|-k] [--thin] [--upload-pack=<git-upload-pack>] [--depth=<n>] [--no-progress] [-v] [<host>:]<directory> [<refs>...]";
  21 static const char *uploadpack = "git-upload-pack";
  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_thin_pack, 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                         parse_commit(commit);
  45
  46                 insert_by_date(commit, &rev_list);
  47
  48                 if (!(commit->object.flags & COMMON))
  49                         non_common_revs++;
  50         }
  51 }
  52
  53 static int rev_list_insert_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
  54 {
  55         struct object *o = deref_tag(parse_object(sha1), path, 0);
  56
  57         if (o && o->type == OBJ_COMMIT)
  58                 rev_list_push((struct commit *)o, SEEN);
  59
  60         return 0;
  61 }
  62
  63 /*
  64    This function marks a rev and its ancestors as common.
  65    In some cases, it is desirable to mark only the ancestors (for example
  66    when only the server does not yet know that they are common).
  67 */
  68
  69 static void mark_common(struct commit *commit,
  70                 int ancestors_only, int dont_parse)
  71 {
  72         if (commit != NULL && !(commit->object.flags & COMMON)) {
  73                 struct object *o = (struct object *)commit;
  74
  75                 if (!ancestors_only)
  76                         o->flags |= COMMON;
  77
  78                 if (!(o->flags & SEEN))
  79                         rev_list_push(commit, SEEN);
  80                 else {
  81                         struct commit_list *parents;
  82
  83                         if (!ancestors_only && !(o->flags & POPPED))
  84                                 non_common_revs--;
  85                         if (!o->parsed && !dont_parse)
  86                                 parse_commit(commit);
  87
  88                         for (parents = commit->parents;
  89                                         parents;
  90                                         parents = parents->next)
  91                                 mark_common(parents->item, 0, dont_parse);
  92                 }
  93         }
  94 }
  95
  96 /*
  97   Get the next rev to send, ignoring the common.
  98 */
  99
 100 static const unsigned char* get_rev(void)
 101 {
 102         struct commit *commit = NULL;
 103
 104         while (commit == NULL) {
 105                 unsigned int mark;
 106                 struct commit_list* parents;
 107
 108                 if (rev_list == NULL || non_common_revs == 0)
 109                         return NULL;
 110
 111                 commit = rev_list->item;
 112                 if (!(commit->object.parsed))
 113                         parse_commit(commit);
 114                 commit->object.flags |= POPPED;
 115                 if (!(commit->object.flags & COMMON))
 116                         non_common_revs--;
 117
 118                 parents = commit->parents;
 119
 120                 if (commit->object.flags & COMMON) {
 121                         /* do not send "have", and ignore ancestors */
 122                         commit = NULL;
 123                         mark = COMMON | SEEN;
 124                 } else if (commit->object.flags & COMMON_REF)
 125                         /* send "have", and ignore ancestors */
 126                         mark = COMMON | SEEN;
 127                 else
 128                         /* send "have", also for its ancestors */
 129                         mark = SEEN;
 130
 131                 while (parents) {
 132                         if (!(parents->item->object.flags & SEEN))
 133                                 rev_list_push(parents->item, mark);
 134                         if (mark & COMMON)
 135                                 mark_common(parents->item, 1, 0);
 136                         parents = parents->next;
 137                 }
 138
 139                 rev_list = rev_list->next;
 140         }
 141
 142         return commit->object.sha1;
 143 }
 144
 145 static int find_common(int fd[2], unsigned char *result_sha1,
 146                        struct ref *refs)
 147 {
 148         int fetching;
 149         int count = 0, flushes = 0, retval;
 150         const unsigned char *sha1;
 151         unsigned in_vain = 0;
 152         int got_continue = 0;
 153
 154         for_each_ref(rev_list_insert_ref, NULL);
 155
 156         fetching = 0;
 157         for ( ; refs ; refs = refs->next) {
 158                 unsigned char *remote = refs->old_sha1;
 159                 struct object *o;
 160
 161                 /*
 162                  * If that object is complete (i.e. it is an ancestor of a
 163                  * local ref), we tell them we have it but do not have to
 164                  * tell them about its ancestors, which they already know
 165                  * about.
 166                  *
 167                  * We use lookup_object here because we are only
 168                  * interested in the case we *know* the object is
 169                  * reachable and we have already scanned it.
 170                  */
 171                 if (((o = lookup_object(remote)) != NULL) &&
 172                                 (o->flags & COMPLETE)) {
 173                         continue;
 174                 }
 175
 176                 if (!fetching)
 177                         packet_write(fd[1], "want %s%s%s%s%s%s%s\n",
 178                                      sha1_to_hex(remote),
 179                                      (multi_ack ? " multi_ack" : ""),
 180                                      (use_sideband == 2 ? " side-band-64k" : ""),
 181                                      (use_sideband == 1 ? " side-band" : ""),
 182                                      (use_thin_pack ? " thin-pack" : ""),
 183                                      (no_progress ? " no-progress" : ""),
 184                                      " ofs-delta");
 185                 else
 186                         packet_write(fd[1], "want %s\n", sha1_to_hex(remote));
 187                 fetching++;
 188         }
 189         if (is_repository_shallow())
 190                 write_shallow_commits(fd[1], 1);
 191         if (depth > 0)
 192                 packet_write(fd[1], "deepen %d", depth);
 193         packet_flush(fd[1]);
 194         if (!fetching)
 195                 return 1;
 196
 197         if (depth > 0) {
 198                 char line[1024];
 199                 unsigned char sha1[20];
 200                 int len;
 201
 202                 while ((len = packet_read_line(fd[0], line, sizeof(line)))) {
 203                         if (!prefixcmp(line, "shallow ")) {
 204                                 if (get_sha1_hex(line + 8, sha1))
 205                                         die("invalid shallow line: %s", line);
 206                                 register_shallow(sha1);
 207                                 continue;
 208                         }
 209                         if (!prefixcmp(line, "unshallow ")) {
 210                                 if (get_sha1_hex(line + 10, sha1))
 211                                         die("invalid unshallow line: %s", line);
 212                                 if (!lookup_object(sha1))
 213                                         die("object not found: %s", line);
 214                                 /* make sure that it is parsed as shallow */
 215                                 parse_object(sha1);
 216                                 if (unregister_shallow(sha1))
 217                                         die("no shallow found: %s", line);
 218                                 continue;
 219                         }
 220                         die("expected shallow/unshallow, got %s", line);
 221                 }
 222         }
 223
 224         flushes = 0;
 225         retval = -1;
 226         while ((sha1 = get_rev())) {
 227                 packet_write(fd[1], "have %s\n", sha1_to_hex(sha1));
 228                 if (verbose)
 229                         fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
 230                 in_vain++;
 231                 if (!(31 & ++count)) {
 232                         int ack;
 233
 234                         packet_flush(fd[1]);
 235                         flushes++;
 236
 237                         /*
 238                          * We keep one window "ahead" of the other side, and
 239                          * will wait for an ACK only on the next one
 240                          */
 241                         if (count == 32)
 242                                 continue;
 243
 244                         do {
 245                                 ack = get_ack(fd[0], result_sha1);
 246                                 if (verbose && ack)
 247                                         fprintf(stderr, "got ack %d %s\n", ack,
 248                                                         sha1_to_hex(result_sha1));
 249                                 if (ack == 1) {
 250                                         flushes = 0;
 251                                         multi_ack = 0;
 252                                         retval = 0;
 253                                         goto done;
 254                                 } else if (ack == 2) {
 255                                         struct commit *commit =
 256                                                 lookup_commit(result_sha1);
 257                                         mark_common(commit, 0, 1);
 258                                         retval = 0;
 259                                         in_vain = 0;
 260                                         got_continue = 1;
 261                                 }
 262                         } while (ack);
 263                         flushes--;
 264                         if (got_continue && MAX_IN_VAIN < in_vain) {
 265                                 if (verbose)
 266                                         fprintf(stderr, "giving up\n");
 267                                 break; /* give up */
 268                         }
 269                 }
 270         }
 271 done:
 272         packet_write(fd[1], "done\n");
 273         if (verbose)
 274                 fprintf(stderr, "done\n");
 275         if (retval != 0) {
 276                 multi_ack = 0;
 277                 flushes++;
 278         }
 279         while (flushes || multi_ack) {
 280                 int ack = get_ack(fd[0], result_sha1);
 281                 if (ack) {
 282                         if (verbose)
 283                                 fprintf(stderr, "got ack (%d) %s\n", ack,
 284                                         sha1_to_hex(result_sha1));
 285                         if (ack == 1)
 286                                 return 0;
 287                         multi_ack = 1;
 288                         continue;
 289                 }
 290                 flushes--;
 291         }
 292         return retval;
 293 }
 294
 295 static struct commit_list *complete;
 296
 297 static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
 298 {
 299         struct object *o = parse_object(sha1);
 300
 301         while (o && o->type == OBJ_TAG) {
 302                 struct tag *t = (struct tag *) o;
 303                 if (!t->tagged)
 304                         break; /* broken repository */
 305                 o->flags |= COMPLETE;
 306                 o = parse_object(t->tagged->sha1);
 307         }
 308         if (o && o->type == OBJ_COMMIT) {
 309                 struct commit *commit = (struct commit *)o;
 310                 commit->object.flags |= COMPLETE;
 311                 insert_by_date(commit, &complete);
 312         }
 313         return 0;
 314 }
 315
 316 static void mark_recent_complete_commits(unsigned long cutoff)
 317 {
 318         while (complete && cutoff <= complete->item->date) {
 319                 if (verbose)
 320                         fprintf(stderr, "Marking %s as complete\n",
 321                                 sha1_to_hex(complete->item->object.sha1));
 322                 pop_most_recent_commit(&complete, COMPLETE);
 323         }
 324 }
 325
 326 static void filter_refs(struct ref **refs, int nr_match, char **match)
 327 {
 328         struct ref **return_refs;
 329         struct ref *newlist = NULL;
 330         struct ref **newtail = &newlist;
 331         struct ref *ref, *next;
 332         struct ref *fastarray[32];
 333
 334         if (nr_match && !fetch_all) {
 335                 if (ARRAY_SIZE(fastarray) < nr_match)
 336                         return_refs = xcalloc(nr_match, sizeof(struct ref *));
 337                 else {
 338                         return_refs = fastarray;
 339                         memset(return_refs, 0, sizeof(struct ref *) * nr_match);
 340                 }
 341         }
 342         else
 343                 return_refs = NULL;
 344
 345         for (ref = *refs; ref; ref = next) {
 346                 next = ref->next;
 347                 if (!memcmp(ref->name, "refs/", 5) &&
 348                     check_ref_format(ref->name + 5))
 349                         ; /* trash */
 350                 else if (fetch_all &&
 351                          (!depth || prefixcmp(ref->name, "refs/tags/") )) {
 352                         *newtail = ref;
 353                         ref->next = NULL;
 354                         newtail = &ref->next;
 355                         continue;
 356                 }
 357                 else {
 358                         int order = path_match(ref->name, nr_match, match);
 359                         if (order) {
 360                                 return_refs[order-1] = ref;
 361                                 continue; /* we will link it later */
 362                         }
 363                 }
 364                 free(ref);
 365         }
 366
 367         if (!fetch_all) {
 368                 int i;
 369                 for (i = 0; i < nr_match; i++) {
 370                         ref = return_refs[i];
 371                         if (ref) {
 372                                 *newtail = ref;
 373                                 ref->next = NULL;
 374                                 newtail = &ref->next;
 375                         }
 376                 }
 377                 if (return_refs != fastarray)
 378                         free(return_refs);
 379         }
 380         *refs = newlist;
 381 }
 382
 383 static int everything_local(struct ref **refs, int nr_match, char **match)
 384 {
 385         struct ref *ref;
 386         int retval;
 387         unsigned long cutoff = 0;
 388
 389         track_object_refs = 0;
 390         save_commit_buffer = 0;
 391
 392         for (ref = *refs; ref; ref = ref->next) {
 393                 struct object *o;
 394
 395                 o = parse_object(ref->old_sha1);
 396                 if (!o)
 397                         continue;
 398
 399                 /* We already have it -- which may mean that we were
 400                  * in sync with the other side at some time after
 401                  * that (it is OK if we guess wrong here).
 402                  */
 403                 if (o->type == OBJ_COMMIT) {
 404                         struct commit *commit = (struct commit *)o;
 405                         if (!cutoff || cutoff < commit->date)
 406                                 cutoff = commit->date;
 407                 }
 408         }
 409
 410         if (!depth) {
 411                 for_each_ref(mark_complete, NULL);
 412                 if (cutoff)
 413                         mark_recent_complete_commits(cutoff);
 414         }
 415
 416         /*
 417          * Mark all complete remote refs as common refs.
 418          * Don't mark them common yet; the server has to be told so first.
 419          */
 420         for (ref = *refs; ref; ref = ref->next) {
 421                 struct object *o = deref_tag(lookup_object(ref->old_sha1),
 422                                              NULL, 0);
 423
 424                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 425                         continue;
 426
 427                 if (!(o->flags & SEEN)) {
 428                         rev_list_push((struct commit *)o, COMMON_REF | SEEN);
 429
 430                         mark_common((struct commit *)o, 1, 1);
 431                 }
 432         }
 433
 434         filter_refs(refs, nr_match, match);
 435
 436         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 437                 const unsigned char *remote = ref->old_sha1;
 438                 unsigned char local[20];
 439                 struct object *o;
 440
 441                 o = lookup_object(remote);
 442                 if (!o || !(o->flags & COMPLETE)) {
 443                         retval = 0;
 444                         if (!verbose)
 445                                 continue;
 446                         fprintf(stderr,
 447                                 "want %s (%s)\n", sha1_to_hex(remote),
 448                                 ref->name);
 449                         continue;
 450                 }
 451
 452                 hashcpy(ref->new_sha1, local);
 453                 if (!verbose)
 454                         continue;
 455                 fprintf(stderr,
 456                         "already have %s (%s)\n", sha1_to_hex(remote),
 457                         ref->name);
 458         }
 459         return retval;
 460 }
 461
 462 static pid_t setup_sideband(int fd[2], int xd[2])
 463 {
 464         pid_t side_pid;
 465
 466         if (!use_sideband) {
 467                 fd[0] = xd[0];
 468                 fd[1] = xd[1];
 469                 return 0;
 470         }
 471         /* xd[] is talking with upload-pack; subprocess reads from
 472          * xd[0], spits out band#2 to stderr, and feeds us band#1
 473          * through our fd[0].
 474          */
 475         if (pipe(fd) < 0)
 476                 die("fetch-pack: unable to set up pipe");
 477         side_pid = fork();
 478         if (side_pid < 0)
 479                 die("fetch-pack: unable to fork off sideband demultiplexer");
 480         if (!side_pid) {
 481                 /* subprocess */
 482                 close(fd[0]);
 483                 if (xd[0] != xd[1])
 484                         close(xd[1]);
 485                 if (recv_sideband("fetch-pack", xd[0], fd[1], 2))
 486                         exit(1);
 487                 exit(0);
 488         }
 489         close(xd[0]);
 490         close(fd[1]);
 491         fd[1] = xd[1];
 492         return side_pid;
 493 }
 494
 495 static int get_pack(int xd[2])
 496 {
 497         int status;
 498         pid_t pid, side_pid;
 499         int fd[2];
 500         const char *argv[20];
 501         char keep_arg[256];
 502         char hdr_arg[256];
 503         const char **av;
 504         int do_keep = keep_pack;
 505
 506         side_pid = setup_sideband(fd, xd);
 507
 508         av = argv;
 509         *hdr_arg = 0;
 510         if (unpack_limit) {
 511                 struct pack_header header;
 512
 513                 if (read_pack_header(fd[0], &header))
 514                         die("protocol error: bad pack header");
 515                 snprintf(hdr_arg, sizeof(hdr_arg), "--pack_header=%u,%u",
 516                          ntohl(header.hdr_version), ntohl(header.hdr_entries));
 517                 if (ntohl(header.hdr_entries) < unpack_limit)
 518                         do_keep = 0;
 519                 else
 520                         do_keep = 1;
 521         }
 522
 523         if (do_keep) {
 524                 *av++ = "index-pack";
 525                 *av++ = "--stdin";
 526                 if (!quiet && !no_progress)
 527                         *av++ = "-v";
 528                 if (use_thin_pack)
 529                         *av++ = "--fix-thin";
 530                 if (keep_pack > 1 || unpack_limit) {
 531                         int s = sprintf(keep_arg,
 532                                         "--keep=fetch-pack %d on ", getpid());
 533                         if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 534                                 strcpy(keep_arg + s, "localhost");
 535                         *av++ = keep_arg;
 536                 }
 537         }
 538         else {
 539                 *av++ = "unpack-objects";
 540                 if (quiet)
 541                         *av++ = "-q";
 542         }
 543         if (*hdr_arg)
 544                 *av++ = hdr_arg;
 545         *av++ = NULL;
 546
 547         pid = spawnv_git_cmd(argv, fd, NULL);
 548         if (pid < 0)
 549                 die("fetch-pack: unable to fork off %s", argv[0]);
 550         close(fd[1]);
 551         while (waitpid(pid, &status, 0) < 0) {
 552                 if (errno != EINTR)
 553                         die("waiting for %s: %s", argv[0], strerror(errno));
 554         }
 555         if (WIFEXITED(status)) {
 556                 int code = WEXITSTATUS(status);
 557                 if (code)
 558                         die("%s died with error code %d", argv[0], code);
 559                 return 0;
 560         }
 561         if (WIFSIGNALED(status)) {
 562                 int sig = WTERMSIG(status);
 563                 die("%s died of signal %d", argv[0], sig);
 564         }
 565         die("%s died of unnatural causes %d", argv[0], status);
 566 }
 567
 568 static int fetch_pack(int fd[2], int nr_match, char **match)
 569 {
 570         struct ref *ref;
 571         unsigned char sha1[20];
 572
 573         get_remote_heads(fd[0], &ref, 0, NULL, 0);
 574         if (is_repository_shallow() && !server_supports("shallow"))
 575                 die("Server does not support shallow clients");
 576         if (server_supports("multi_ack")) {
 577                 if (verbose)
 578                         fprintf(stderr, "Server supports multi_ack\n");
 579                 multi_ack = 1;
 580         }
 581 #ifndef __MINGW32__
 582         if (server_supports("side-band-64k")) {
 583                 if (verbose)
 584                         fprintf(stderr, "Server supports side-band-64k\n");
 585                 use_sideband = 2;
 586         }
 587         else if (server_supports("side-band")) {
 588                 if (verbose)
 589                         fprintf(stderr, "Server supports side-band\n");
 590                 use_sideband = 1;
 591         }
 592 #endif
 593         if (!ref) {
 594                 packet_flush(fd[1]);
 595                 die("no matching remote head");
 596         }
 597         if (everything_local(&ref, nr_match, match)) {
 598                 packet_flush(fd[1]);
 599                 goto all_done;
 600         }
 601         if (find_common(fd, sha1, ref) < 0)
 602                 if (keep_pack != 1)
 603                         /* When cloning, it is not unusual to have
 604                          * no common commit.
 605                          */
 606                         fprintf(stderr, "warning: no common commits\n");
 607
 608         if (get_pack(fd))
 609                 die("git-fetch-pack: fetch failed.");
 610
 611  all_done:
 612         while (ref) {
 613                 printf("%s %s\n",
 614                        sha1_to_hex(ref->old_sha1), ref->name);
 615                 ref = ref->next;
 616         }
 617         return 0;
 618 }
 619
 620 static int remove_duplicates(int nr_heads, char **heads)
 621 {
 622         int src, dst;
 623
 624         for (src = dst = 0; src < nr_heads; src++) {
 625                 /* If heads[src] is different from any of
 626                  * heads[0..dst], push it in.
 627                  */
 628                 int i;
 629                 for (i = 0; i < dst; i++) {
 630                         if (!strcmp(heads[i], heads[src]))
 631                                 break;
 632                 }
 633                 if (i < dst)
 634                         continue;
 635                 if (src != dst)
 636                         heads[dst] = heads[src];
 637                 dst++;
 638         }
 639         heads[dst] = 0;
 640         return dst;
 641 }
 642
 643 static int fetch_pack_config(const char *var, const char *value)
 644 {
 645         if (strcmp(var, "fetch.unpacklimit") == 0) {
 646                 fetch_unpack_limit = git_config_int(var, value);
 647                 return 0;
 648         }
 649
 650         if (strcmp(var, "transfer.unpacklimit") == 0) {
 651                 transfer_unpack_limit = git_config_int(var, value);
 652                 return 0;
 653         }
 654
 655         return git_default_config(var, value);
 656 }
 657
 658 static struct lock_file lock;
 659
 660 int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 661 {
 662         int i, ret, nr_heads;
 663         char *dest = NULL, **heads;
 664         int fd[2];
 665         pid_t pid;
 666         struct stat st;
 667
 668         git_config(fetch_pack_config);
 669
 670         if (0 <= transfer_unpack_limit)
 671                 unpack_limit = transfer_unpack_limit;
 672         else if (0 <= fetch_unpack_limit)
 673                 unpack_limit = fetch_unpack_limit;
 674
 675         nr_heads = 0;
 676         heads = NULL;
 677         for (i = 1; i < argc; i++) {
 678                 char *arg = argv[i];
 679
 680                 if (*arg == '-') {
 681                         if (!prefixcmp(arg, "--upload-pack=")) {
 682                                 uploadpack = arg + 14;
 683                                 continue;
 684                         }
 685                         if (!prefixcmp(arg, "--exec=")) {
 686                                 uploadpack = arg + 7;
 687                                 continue;
 688                         }
 689                         if (!strcmp("--quiet", arg) || !strcmp("-q", arg)) {
 690                                 quiet = 1;
 691                                 continue;
 692                         }
 693                         if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
 694                                 keep_pack++;
 695                                 unpack_limit = 0;
 696                                 continue;
 697                         }
 698                         if (!strcmp("--thin", arg)) {
 699                                 use_thin_pack = 1;
 700                                 continue;
 701                         }
 702                         if (!strcmp("--all", arg)) {
 703                                 fetch_all = 1;
 704                                 continue;
 705                         }
 706                         if (!strcmp("-v", arg)) {
 707                                 verbose = 1;
 708                                 continue;
 709                         }
 710                         if (!prefixcmp(arg, "--depth=")) {
 711                                 depth = strtol(arg + 8, NULL, 0);
 712                                 if (stat(git_path("shallow"), &st))
 713                                         st.st_mtime = 0;
 714                                 continue;
 715                         }
 716                         if (!strcmp("--no-progress", arg)) {
 717                                 no_progress = 1;
 718                                 continue;
 719                         }
 720                         usage(fetch_pack_usage);
 721                 }
 722                 dest = arg;
 723                 heads = argv + i + 1;
 724                 nr_heads = argc - i - 1;
 725                 break;
 726         }
 727         if (!dest)
 728                 usage(fetch_pack_usage);
 729         pid = git_connect(fd, dest, uploadpack, verbose ? CONNECT_VERBOSE : 0);
 730         if (pid < 0)
 731                 return 1;
 732         if (heads && nr_heads)
 733                 nr_heads = remove_duplicates(nr_heads, heads);
 734         ret = fetch_pack(fd, nr_heads, heads);
 735         close(fd[0]);
 736         close(fd[1]);
 737         ret |= finish_connect(pid);
 738
 739         if (!ret && nr_heads) {
 740                 /* If the heads to pull were given, we should have
 741                  * consumed all of them by matching the remote.
 742                  * Otherwise, 'git-fetch remote no-such-ref' would
 743                  * silently succeed without issuing an error.
 744                  */
 745                 for (i = 0; i < nr_heads; i++)
 746                         if (heads[i] && heads[i][0]) {
 747                                 error("no such remote ref %s", heads[i]);
 748                                 ret = 1;
 749                         }
 750         }
 751
 752         if (!ret && depth > 0) {
 753                 struct cache_time mtime;
 754                 char *shallow = git_path("shallow");
 755                 int fd;
 756
 757                 mtime.sec = st.st_mtime;
 758 #ifdef USE_NSEC
 759                 mtime.usec = st.st_mtim.usec;
 760 #endif
 761                 if (stat(shallow, &st)) {
 762                         if (mtime.sec)
 763                                 die("shallow file was removed during fetch");
 764                 } else if (st.st_mtime != mtime.sec
 765 #ifdef USE_NSEC
 766                                 || st.st_mtim.usec != mtime.usec
 767 #endif
 768                           )
 769                         die("shallow file was changed during fetch");
 770
 771                 fd = hold_lock_file_for_update(&lock, shallow, 1);
 772                 if (!write_shallow_commits(fd, 0)) {
 773                         unlink(shallow);
 774                         rollback_lock_file(&lock);
 775                 } else {
 776                         close(fd);
 777                         commit_lock_file(&lock);
 778                 }
 779         }
 780
 781         return !!ret;
 782 }