git.oblomov.eu Git - git/blob - 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] [--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                         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                                      (args.use_thin_pack ? " thin-pack" : ""),
 183                                      (args.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 (args.depth > 0)
 192                 packet_write(fd[1], "deepen %d", args.depth);
 193         packet_flush(fd[1]);
 194         if (!fetching)
 195                 return 1;
 196
 197         if (args.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 (args.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 (args.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 (args.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 (args.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 (args.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 (args.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 && !args.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 (args.fetch_all &&
 351                          (!args.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 (!args.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         save_commit_buffer = 0;
 390
 391         for (ref = *refs; ref; ref = ref->next) {
 392                 struct object *o;
 393
 394                 o = parse_object(ref->old_sha1);
 395                 if (!o)
 396                         continue;
 397
 398                 /* We already have it -- which may mean that we were
 399                  * in sync with the other side at some time after
 400                  * that (it is OK if we guess wrong here).
 401                  */
 402                 if (o->type == OBJ_COMMIT) {
 403                         struct commit *commit = (struct commit *)o;
 404                         if (!cutoff || cutoff < commit->date)
 405                                 cutoff = commit->date;
 406                 }
 407         }
 408
 409         if (!args.depth) {
 410                 for_each_ref(mark_complete, NULL);
 411                 if (cutoff)
 412                         mark_recent_complete_commits(cutoff);
 413         }
 414
 415         /*
 416          * Mark all complete remote refs as common refs.
 417          * Don't mark them common yet; the server has to be told so first.
 418          */
 419         for (ref = *refs; ref; ref = ref->next) {
 420                 struct object *o = deref_tag(lookup_object(ref->old_sha1),
 421                                              NULL, 0);
 422
 423                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 424                         continue;
 425
 426                 if (!(o->flags & SEEN)) {
 427                         rev_list_push((struct commit *)o, COMMON_REF | SEEN);
 428
 429                         mark_common((struct commit *)o, 1, 1);
 430                 }
 431         }
 432
 433         filter_refs(refs, nr_match, match);
 434
 435         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 436                 const unsigned char *remote = ref->old_sha1;
 437                 unsigned char local[20];
 438                 struct object *o;
 439
 440                 o = lookup_object(remote);
 441                 if (!o || !(o->flags & COMPLETE)) {
 442                         retval = 0;
 443                         if (!args.verbose)
 444                                 continue;
 445                         fprintf(stderr,
 446                                 "want %s (%s)\n", sha1_to_hex(remote),
 447                                 ref->name);
 448                         continue;
 449                 }
 450
 451                 hashcpy(ref->new_sha1, local);
 452                 if (!args.verbose)
 453                         continue;
 454                 fprintf(stderr,
 455                         "already have %s (%s)\n", sha1_to_hex(remote),
 456                         ref->name);
 457         }
 458         return retval;
 459 }
 460
 461 static int sideband_demux(int fd, void *data)
 462 {
 463         int *xd = data;
 464
 465         return recv_sideband("fetch-pack", xd[0], fd, 2);
 466 }
 467
 468 static int get_pack(int xd[2], char **pack_lockfile)
 469 {
 470         struct async demux;
 471         const char *argv[20];
 472         char keep_arg[256];
 473         char hdr_arg[256];
 474         const char **av;
 475         int do_keep = args.keep_pack;
 476         struct child_process cmd;
 477
 478         memset(&demux, 0, sizeof(demux));
 479         if (use_sideband) {
 480                 /* xd[] is talking with upload-pack; subprocess reads from
 481                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 482                  * through demux->out.
 483                  */
 484                 demux.proc = sideband_demux;
 485                 demux.data = xd;
 486                 if (start_async(&demux))
 487                         die("fetch-pack: unable to fork off sideband"
 488                             " demultiplexer");
 489         }
 490         else
 491                 demux.out = xd[0];
 492
 493         memset(&cmd, 0, sizeof(cmd));
 494         cmd.argv = argv;
 495         av = argv;
 496         *hdr_arg = 0;
 497         if (!args.keep_pack && unpack_limit) {
 498                 struct pack_header header;
 499
 500                 if (read_pack_header(demux.out, &header))
 501                         die("protocol error: bad pack header");
 502                 snprintf(hdr_arg, sizeof(hdr_arg), "--pack_header=%u,%u",
 503                          ntohl(header.hdr_version), ntohl(header.hdr_entries));
 504                 if (ntohl(header.hdr_entries) < unpack_limit)
 505                         do_keep = 0;
 506                 else
 507                         do_keep = 1;
 508         }
 509
 510         if (do_keep) {
 511                 if (pack_lockfile)
 512                         cmd.out = -1;
 513                 *av++ = "index-pack";
 514                 *av++ = "--stdin";
 515                 if (!args.quiet && !args.no_progress)
 516                         *av++ = "-v";
 517                 if (args.use_thin_pack)
 518                         *av++ = "--fix-thin";
 519                 if (args.lock_pack || unpack_limit) {
 520                         int s = sprintf(keep_arg,
 521                                         "--keep=fetch-pack %d on ", getpid());
 522                         if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
 523                                 strcpy(keep_arg + s, "localhost");
 524                         *av++ = keep_arg;
 525                 }
 526         }
 527         else {
 528                 *av++ = "unpack-objects";
 529                 if (args.quiet)
 530                         *av++ = "-q";
 531         }
 532         if (*hdr_arg)
 533                 *av++ = hdr_arg;
 534         *av++ = NULL;
 535
 536         cmd.in = demux.out;
 537         cmd.git_cmd = 1;
 538         if (start_command(&cmd))
 539                 die("fetch-pack: unable to fork off %s", argv[0]);
 540         if (do_keep && pack_lockfile) {
 541                 *pack_lockfile = index_pack_lockfile(cmd.out);
 542                 close(cmd.out);
 543         }
 544
 545         if (finish_command(&cmd))
 546                 die("%s failed", argv[0]);
 547         if (use_sideband && finish_async(&demux))
 548                 die("error in sideband demultiplexer");
 549         return 0;
 550 }
 551
 552 static struct ref *do_fetch_pack(int fd[2],
 553                 const struct ref *orig_ref,
 554                 int nr_match,
 555                 char **match,
 556                 char **pack_lockfile)
 557 {
 558         struct ref *ref = copy_ref_list(orig_ref);
 559         unsigned char sha1[20];
 560
 561         if (is_repository_shallow() && !server_supports("shallow"))
 562                 die("Server does not support shallow clients");
 563         if (server_supports("multi_ack")) {
 564                 if (args.verbose)
 565                         fprintf(stderr, "Server supports multi_ack\n");
 566                 multi_ack = 1;
 567         }
 568         if (server_supports("side-band-64k")) {
 569                 if (args.verbose)
 570                         fprintf(stderr, "Server supports side-band-64k\n");
 571                 use_sideband = 2;
 572         }
 573         else if (server_supports("side-band")) {
 574                 if (args.verbose)
 575                         fprintf(stderr, "Server supports side-band\n");
 576                 use_sideband = 1;
 577         }
 578         if (everything_local(&ref, nr_match, match)) {
 579                 packet_flush(fd[1]);
 580                 goto all_done;
 581         }
 582         if (find_common(fd, sha1, ref) < 0)
 583                 if (!args.keep_pack)
 584                         /* When cloning, it is not unusual to have
 585                          * no common commit.
 586                          */
 587                         fprintf(stderr, "warning: no common commits\n");
 588
 589         if (get_pack(fd, pack_lockfile))
 590                 die("git-fetch-pack: fetch failed.");
 591
 592  all_done:
 593         return ref;
 594 }
 595
 596 static int remove_duplicates(int nr_heads, char **heads)
 597 {
 598         int src, dst;
 599
 600         for (src = dst = 0; src < nr_heads; src++) {
 601                 /* If heads[src] is different from any of
 602                  * heads[0..dst], push it in.
 603                  */
 604                 int i;
 605                 for (i = 0; i < dst; i++) {
 606                         if (!strcmp(heads[i], heads[src]))
 607                                 break;
 608                 }
 609                 if (i < dst)
 610                         continue;
 611                 if (src != dst)
 612                         heads[dst] = heads[src];
 613                 dst++;
 614         }
 615         return dst;
 616 }
 617
 618 static int fetch_pack_config(const char *var, const char *value)
 619 {
 620         if (strcmp(var, "fetch.unpacklimit") == 0) {
 621                 fetch_unpack_limit = git_config_int(var, value);
 622                 return 0;
 623         }
 624
 625         if (strcmp(var, "transfer.unpacklimit") == 0) {
 626                 transfer_unpack_limit = git_config_int(var, value);
 627                 return 0;
 628         }
 629
 630         return git_default_config(var, value);
 631 }
 632
 633 static struct lock_file lock;
 634
 635 static void fetch_pack_setup(void)
 636 {
 637         static int did_setup;
 638         if (did_setup)
 639                 return;
 640         git_config(fetch_pack_config);
 641         if (0 <= transfer_unpack_limit)
 642                 unpack_limit = transfer_unpack_limit;
 643         else if (0 <= fetch_unpack_limit)
 644                 unpack_limit = fetch_unpack_limit;
 645         did_setup = 1;
 646 }
 647
 648 int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
 649 {
 650         int i, ret, nr_heads;
 651         struct ref *ref = NULL;
 652         char *dest = NULL, **heads;
 653         int fd[2];
 654         struct child_process *conn;
 655
 656         nr_heads = 0;
 657         heads = NULL;
 658         for (i = 1; i < argc; i++) {
 659                 const char *arg = argv[i];
 660
 661                 if (*arg == '-') {
 662                         if (!prefixcmp(arg, "--upload-pack=")) {
 663                                 args.uploadpack = arg + 14;
 664                                 continue;
 665                         }
 666                         if (!prefixcmp(arg, "--exec=")) {
 667                                 args.uploadpack = arg + 7;
 668                                 continue;
 669                         }
 670                         if (!strcmp("--quiet", arg) || !strcmp("-q", arg)) {
 671                                 args.quiet = 1;
 672                                 continue;
 673                         }
 674                         if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
 675                                 args.lock_pack = args.keep_pack;
 676                                 args.keep_pack = 1;
 677                                 continue;
 678                         }
 679                         if (!strcmp("--thin", arg)) {
 680                                 args.use_thin_pack = 1;
 681                                 continue;
 682                         }
 683                         if (!strcmp("--all", arg)) {
 684                                 args.fetch_all = 1;
 685                                 continue;
 686                         }
 687                         if (!strcmp("-v", arg)) {
 688                                 args.verbose = 1;
 689                                 continue;
 690                         }
 691                         if (!prefixcmp(arg, "--depth=")) {
 692                                 args.depth = strtol(arg + 8, NULL, 0);
 693                                 continue;
 694                         }
 695                         if (!strcmp("--no-progress", arg)) {
 696                                 args.no_progress = 1;
 697                                 continue;
 698                         }
 699                         usage(fetch_pack_usage);
 700                 }
 701                 dest = (char *)arg;
 702                 heads = (char **)(argv + i + 1);
 703                 nr_heads = argc - i - 1;
 704                 break;
 705         }
 706         if (!dest)
 707                 usage(fetch_pack_usage);
 708
 709         conn = git_connect(fd, (char *)dest, args.uploadpack,
 710                            args.verbose ? CONNECT_VERBOSE : 0);
 711         if (conn) {
 712                 get_remote_heads(fd[0], &ref, 0, NULL, 0);
 713
 714                 ref = fetch_pack(&args, fd, conn, ref, dest, nr_heads, heads, NULL);
 715                 close(fd[0]);
 716                 close(fd[1]);
 717                 if (finish_connect(conn))
 718                         ref = NULL;
 719         } else {
 720                 ref = NULL;
 721         }
 722         ret = !ref;
 723
 724         if (!ret && nr_heads) {
 725                 /* If the heads to pull were given, we should have
 726                  * consumed all of them by matching the remote.
 727                  * Otherwise, 'git-fetch remote no-such-ref' would
 728                  * silently succeed without issuing an error.
 729                  */
 730                 for (i = 0; i < nr_heads; i++)
 731                         if (heads[i] && heads[i][0]) {
 732                                 error("no such remote ref %s", heads[i]);
 733                                 ret = 1;
 734                         }
 735         }
 736         while (ref) {
 737                 printf("%s %s\n",
 738                        sha1_to_hex(ref->old_sha1), ref->name);
 739                 ref = ref->next;
 740         }
 741
 742         return ret;
 743 }
 744
 745 struct ref *fetch_pack(struct fetch_pack_args *my_args,
 746                        int fd[], struct child_process *conn,
 747                        const struct ref *ref,
 748                 const char *dest,
 749                 int nr_heads,
 750                 char **heads,
 751                 char **pack_lockfile)
 752 {
 753         struct stat st;
 754         struct ref *ref_cpy;
 755
 756         fetch_pack_setup();
 757         memcpy(&args, my_args, sizeof(args));
 758         if (args.depth > 0) {
 759                 if (stat(git_path("shallow"), &st))
 760                         st.st_mtime = 0;
 761         }
 762
 763         if (heads && nr_heads)
 764                 nr_heads = remove_duplicates(nr_heads, heads);
 765         if (!ref) {
 766                 packet_flush(fd[1]);
 767                 die("no matching remote head");
 768         }
 769         ref_cpy = do_fetch_pack(fd, ref, nr_heads, heads, pack_lockfile);
 770
 771         if (args.depth > 0) {
 772                 struct cache_time mtime;
 773                 char *shallow = git_path("shallow");
 774                 int fd;
 775
 776                 mtime.sec = st.st_mtime;
 777 #ifdef USE_NSEC
 778                 mtime.usec = st.st_mtim.usec;
 779 #endif
 780                 if (stat(shallow, &st)) {
 781                         if (mtime.sec)
 782                                 die("shallow file was removed during fetch");
 783                 } else if (st.st_mtime != mtime.sec
 784 #ifdef USE_NSEC
 785                                 || st.st_mtim.usec != mtime.usec
 786 #endif
 787                           )
 788                         die("shallow file was changed during fetch");
 789
 790                 fd = hold_lock_file_for_update(&lock, shallow, 1);
 791                 if (!write_shallow_commits(fd, 0)) {
 792                         unlink(shallow);
 793                         rollback_lock_file(&lock);
 794                 } else {
 795                         commit_lock_file(&lock);
 796                 }
 797         }
 798
 799         return ref_cpy;
 800 }