git.oblomov.eu Git - git/blob - fetch-pack.c

   1 #include "cache.h"
   2 #include "repository.h"
   3 #include "config.h"
   4 #include "lockfile.h"
   5 #include "refs.h"
   6 #include "pkt-line.h"
   7 #include "commit.h"
   8 #include "tag.h"
   9 #include "exec-cmd.h"
  10 #include "pack.h"
  11 #include "sideband.h"
  12 #include "fetch-pack.h"
  13 #include "remote.h"
  14 #include "run-command.h"
  15 #include "connect.h"
  16 #include "transport.h"
  17 #include "version.h"
  18 #include "sha1-array.h"
  19 #include "oidset.h"
  20 #include "packfile.h"
  21 #include "object-store.h"
  22 #include "connected.h"
  23 #include "fetch-negotiator.h"
  24 #include "fsck.h"
  25
  26 static int transfer_unpack_limit = -1;
  27 static int fetch_unpack_limit = -1;
  28 static int unpack_limit = 100;
  29 static int prefer_ofs_delta = 1;
  30 static int no_done;
  31 static int deepen_since_ok;
  32 static int deepen_not_ok;
  33 static int fetch_fsck_objects = -1;
  34 static int transfer_fsck_objects = -1;
  35 static int agent_supported;
  36 static int server_supports_filtering;
  37 static struct lock_file shallow_lock;
  38 static const char *alternate_shallow_file;
  39 static struct strbuf fsck_msg_types = STRBUF_INIT;
  40
  41 /* Remember to update object flag allocation in object.h */
  42 #define COMPLETE        (1U << 0)
  43 #define ALTERNATE       (1U << 1)
  44
  45 /*
  46  * After sending this many "have"s if we do not get any new ACK , we
  47  * give up traversing our history.
  48  */
  49 #define MAX_IN_VAIN 256
  50
  51 static int multi_ack, use_sideband;
  52 /* Allow specifying sha1 if it is a ref tip. */
  53 #define ALLOW_TIP_SHA1  01
  54 /* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
  55 #define ALLOW_REACHABLE_SHA1    02
  56 static unsigned int allow_unadvertised_object_request;
  57
  58 __attribute__((format (printf, 2, 3)))
  59 static inline void print_verbose(const struct fetch_pack_args *args,
  60                                  const char *fmt, ...)
  61 {
  62         va_list params;
  63
  64         if (!args->verbose)
  65                 return;
  66
  67         va_start(params, fmt);
  68         vfprintf(stderr, fmt, params);
  69         va_end(params);
  70         fputc('\n', stderr);
  71 }
  72
  73 struct alternate_object_cache {
  74         struct object **items;
  75         size_t nr, alloc;
  76 };
  77
  78 static void cache_one_alternate(const struct object_id *oid,
  79                                 void *vcache)
  80 {
  81         struct alternate_object_cache *cache = vcache;
  82         struct object *obj = parse_object(the_repository, oid);
  83
  84         if (!obj || (obj->flags & ALTERNATE))
  85                 return;
  86
  87         obj->flags |= ALTERNATE;
  88         ALLOC_GROW(cache->items, cache->nr + 1, cache->alloc);
  89         cache->items[cache->nr++] = obj;
  90 }
  91
  92 static void for_each_cached_alternate(struct fetch_negotiator *negotiator,
  93                                       void (*cb)(struct fetch_negotiator *,
  94                                                  struct object *))
  95 {
  96         static int initialized;
  97         static struct alternate_object_cache cache;
  98         size_t i;
  99
 100         if (!initialized) {
 101                 for_each_alternate_ref(cache_one_alternate, &cache);
 102                 initialized = 1;
 103         }
 104
 105         for (i = 0; i < cache.nr; i++)
 106                 cb(negotiator, cache.items[i]);
 107 }
 108
 109 static int rev_list_insert_ref(struct fetch_negotiator *negotiator,
 110                                const char *refname,
 111                                const struct object_id *oid)
 112 {
 113         struct object *o = deref_tag(the_repository,
 114                                      parse_object(the_repository, oid),
 115                                      refname, 0);
 116
 117         if (o && o->type == OBJ_COMMIT)
 118                 negotiator->add_tip(negotiator, (struct commit *)o);
 119
 120         return 0;
 121 }
 122
 123 static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
 124                                    int flag, void *cb_data)
 125 {
 126         return rev_list_insert_ref(cb_data, refname, oid);
 127 }
 128
 129 enum ack_type {
 130         NAK = 0,
 131         ACK,
 132         ACK_continue,
 133         ACK_common,
 134         ACK_ready
 135 };
 136
 137 static void consume_shallow_list(struct fetch_pack_args *args,
 138                                  struct packet_reader *reader)
 139 {
 140         if (args->stateless_rpc && args->deepen) {
 141                 /* If we sent a depth we will get back "duplicate"
 142                  * shallow and unshallow commands every time there
 143                  * is a block of have lines exchanged.
 144                  */
 145                 while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
 146                         if (starts_with(reader->line, "shallow "))
 147                                 continue;
 148                         if (starts_with(reader->line, "unshallow "))
 149                                 continue;
 150                         die(_("git fetch-pack: expected shallow list"));
 151                 }
 152                 if (reader->status != PACKET_READ_FLUSH)
 153                         die(_("git fetch-pack: expected a flush packet after shallow list"));
 154         }
 155 }
 156
 157 static enum ack_type get_ack(struct packet_reader *reader,
 158                              struct object_id *result_oid)
 159 {
 160         int len;
 161         const char *arg;
 162
 163         if (packet_reader_read(reader) != PACKET_READ_NORMAL)
 164                 die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
 165         len = reader->pktlen;
 166
 167         if (!strcmp(reader->line, "NAK"))
 168                 return NAK;
 169         if (skip_prefix(reader->line, "ACK ", &arg)) {
 170                 const char *p;
 171                 if (!parse_oid_hex(arg, result_oid, &p)) {
 172                         len -= p - reader->line;
 173                         if (len < 1)
 174                                 return ACK;
 175                         if (strstr(p, "continue"))
 176                                 return ACK_continue;
 177                         if (strstr(p, "common"))
 178                                 return ACK_common;
 179                         if (strstr(p, "ready"))
 180                                 return ACK_ready;
 181                         return ACK;
 182                 }
 183         }
 184         die(_("git fetch-pack: expected ACK/NAK, got '%s'"), reader->line);
 185 }
 186
 187 static void send_request(struct fetch_pack_args *args,
 188                          int fd, struct strbuf *buf)
 189 {
 190         if (args->stateless_rpc) {
 191                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 192                 packet_flush(fd);
 193         } else {
 194                 if (write_in_full(fd, buf->buf, buf->len) < 0)
 195                         die_errno(_("unable to write to remote"));
 196         }
 197 }
 198
 199 static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
 200                                         struct object *obj)
 201 {
 202         rev_list_insert_ref(negotiator, NULL, &obj->oid);
 203 }
 204
 205 #define INITIAL_FLUSH 16
 206 #define PIPESAFE_FLUSH 32
 207 #define LARGE_FLUSH 16384
 208
 209 static int next_flush(int stateless_rpc, int count)
 210 {
 211         if (stateless_rpc) {
 212                 if (count < LARGE_FLUSH)
 213                         count <<= 1;
 214                 else
 215                         count = count * 11 / 10;
 216         } else {
 217                 if (count < PIPESAFE_FLUSH)
 218                         count <<= 1;
 219                 else
 220                         count += PIPESAFE_FLUSH;
 221         }
 222         return count;
 223 }
 224
 225 static void mark_tips(struct fetch_negotiator *negotiator,
 226                       const struct oid_array *negotiation_tips)
 227 {
 228         int i;
 229
 230         if (!negotiation_tips) {
 231                 for_each_ref(rev_list_insert_ref_oid, negotiator);
 232                 return;
 233         }
 234
 235         for (i = 0; i < negotiation_tips->nr; i++)
 236                 rev_list_insert_ref(negotiator, NULL,
 237                                     &negotiation_tips->oid[i]);
 238         return;
 239 }
 240
 241 static int find_common(struct fetch_negotiator *negotiator,
 242                        struct fetch_pack_args *args,
 243                        int fd[2], struct object_id *result_oid,
 244                        struct ref *refs)
 245 {
 246         int fetching;
 247         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
 248         const struct object_id *oid;
 249         unsigned in_vain = 0;
 250         int got_continue = 0;
 251         int got_ready = 0;
 252         struct strbuf req_buf = STRBUF_INIT;
 253         size_t state_len = 0;
 254         struct packet_reader reader;
 255
 256         if (args->stateless_rpc && multi_ack == 1)
 257                 die(_("--stateless-rpc requires multi_ack_detailed"));
 258
 259         packet_reader_init(&reader, fd[0], NULL, 0,
 260                            PACKET_READ_CHOMP_NEWLINE |
 261                            PACKET_READ_DIE_ON_ERR_PACKET);
 262
 263         if (!args->no_dependents) {
 264                 mark_tips(negotiator, args->negotiation_tips);
 265                 for_each_cached_alternate(negotiator, insert_one_alternate_object);
 266         }
 267
 268         fetching = 0;
 269         for ( ; refs ; refs = refs->next) {
 270                 struct object_id *remote = &refs->old_oid;
 271                 const char *remote_hex;
 272                 struct object *o;
 273
 274                 /*
 275                  * If that object is complete (i.e. it is an ancestor of a
 276                  * local ref), we tell them we have it but do not have to
 277                  * tell them about its ancestors, which they already know
 278                  * about.
 279                  *
 280                  * We use lookup_object here because we are only
 281                  * interested in the case we *know* the object is
 282                  * reachable and we have already scanned it.
 283                  *
 284                  * Do this only if args->no_dependents is false (if it is true,
 285                  * we cannot trust the object flags).
 286                  */
 287                 if (!args->no_dependents &&
 288                     ((o = lookup_object(the_repository, remote)) != NULL) &&
 289                                 (o->flags & COMPLETE)) {
 290                         continue;
 291                 }
 292
 293                 remote_hex = oid_to_hex(remote);
 294                 if (!fetching) {
 295                         struct strbuf c = STRBUF_INIT;
 296                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
 297                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
 298                         if (no_done)            strbuf_addstr(&c, " no-done");
 299                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
 300                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
 301                         if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
 302                         if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
 303                         if (args->no_progress)   strbuf_addstr(&c, " no-progress");
 304                         if (args->include_tag)   strbuf_addstr(&c, " include-tag");
 305                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
 306                         if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
 307                         if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 308                         if (agent_supported)    strbuf_addf(&c, " agent=%s",
 309                                                             git_user_agent_sanitized());
 310                         if (args->filter_options.choice)
 311                                 strbuf_addstr(&c, " filter");
 312                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 313                         strbuf_release(&c);
 314                 } else
 315                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
 316                 fetching++;
 317         }
 318
 319         if (!fetching) {
 320                 strbuf_release(&req_buf);
 321                 packet_flush(fd[1]);
 322                 return 1;
 323         }
 324
 325         if (is_repository_shallow(the_repository))
 326                 write_shallow_commits(&req_buf, 1, NULL);
 327         if (args->depth > 0)
 328                 packet_buf_write(&req_buf, "deepen %d", args->depth);
 329         if (args->deepen_since) {
 330                 timestamp_t max_age = approxidate(args->deepen_since);
 331                 packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
 332         }
 333         if (args->deepen_not) {
 334                 int i;
 335                 for (i = 0; i < args->deepen_not->nr; i++) {
 336                         struct string_list_item *s = args->deepen_not->items + i;
 337                         packet_buf_write(&req_buf, "deepen-not %s", s->string);
 338                 }
 339         }
 340         if (server_supports_filtering && args->filter_options.choice) {
 341                 const char *spec =
 342                         expand_list_objects_filter_spec(&args->filter_options);
 343                 packet_buf_write(&req_buf, "filter %s", spec);
 344         }
 345         packet_buf_flush(&req_buf);
 346         state_len = req_buf.len;
 347
 348         if (args->deepen) {
 349                 const char *arg;
 350                 struct object_id oid;
 351
 352                 send_request(args, fd[1], &req_buf);
 353                 while (packet_reader_read(&reader) == PACKET_READ_NORMAL) {
 354                         if (skip_prefix(reader.line, "shallow ", &arg)) {
 355                                 if (get_oid_hex(arg, &oid))
 356                                         die(_("invalid shallow line: %s"), reader.line);
 357                                 register_shallow(the_repository, &oid);
 358                                 continue;
 359                         }
 360                         if (skip_prefix(reader.line, "unshallow ", &arg)) {
 361                                 if (get_oid_hex(arg, &oid))
 362                                         die(_("invalid unshallow line: %s"), reader.line);
 363                                 if (!lookup_object(the_repository, &oid))
 364                                         die(_("object not found: %s"), reader.line);
 365                                 /* make sure that it is parsed as shallow */
 366                                 if (!parse_object(the_repository, &oid))
 367                                         die(_("error in object: %s"), reader.line);
 368                                 if (unregister_shallow(&oid))
 369                                         die(_("no shallow found: %s"), reader.line);
 370                                 continue;
 371                         }
 372                         die(_("expected shallow/unshallow, got %s"), reader.line);
 373                 }
 374         } else if (!args->stateless_rpc)
 375                 send_request(args, fd[1], &req_buf);
 376
 377         if (!args->stateless_rpc) {
 378                 /* If we aren't using the stateless-rpc interface
 379                  * we don't need to retain the headers.
 380                  */
 381                 strbuf_setlen(&req_buf, 0);
 382                 state_len = 0;
 383         }
 384
 385         flushes = 0;
 386         retval = -1;
 387         if (args->no_dependents)
 388                 goto done;
 389         while ((oid = negotiator->next(negotiator))) {
 390                 packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
 391                 print_verbose(args, "have %s", oid_to_hex(oid));
 392                 in_vain++;
 393                 if (flush_at <= ++count) {
 394                         int ack;
 395
 396                         packet_buf_flush(&req_buf);
 397                         send_request(args, fd[1], &req_buf);
 398                         strbuf_setlen(&req_buf, state_len);
 399                         flushes++;
 400                         flush_at = next_flush(args->stateless_rpc, count);
 401
 402                         /*
 403                          * We keep one window "ahead" of the other side, and
 404                          * will wait for an ACK only on the next one
 405                          */
 406                         if (!args->stateless_rpc && count == INITIAL_FLUSH)
 407                                 continue;
 408
 409                         consume_shallow_list(args, &reader);
 410                         do {
 411                                 ack = get_ack(&reader, result_oid);
 412                                 if (ack)
 413                                         print_verbose(args, _("got %s %d %s"), "ack",
 414                                                       ack, oid_to_hex(result_oid));
 415                                 switch (ack) {
 416                                 case ACK:
 417                                         flushes = 0;
 418                                         multi_ack = 0;
 419                                         retval = 0;
 420                                         goto done;
 421                                 case ACK_common:
 422                                 case ACK_ready:
 423                                 case ACK_continue: {
 424                                         struct commit *commit =
 425                                                 lookup_commit(the_repository,
 426                                                               result_oid);
 427                                         int was_common;
 428
 429                                         if (!commit)
 430                                                 die(_("invalid commit %s"), oid_to_hex(result_oid));
 431                                         was_common = negotiator->ack(negotiator, commit);
 432                                         if (args->stateless_rpc
 433                                          && ack == ACK_common
 434                                          && !was_common) {
 435                                                 /* We need to replay the have for this object
 436                                                  * on the next RPC request so the peer knows
 437                                                  * it is in common with us.
 438                                                  */
 439                                                 const char *hex = oid_to_hex(result_oid);
 440                                                 packet_buf_write(&req_buf, "have %s\n", hex);
 441                                                 state_len = req_buf.len;
 442                                                 /*
 443                                                  * Reset in_vain because an ack
 444                                                  * for this commit has not been
 445                                                  * seen.
 446                                                  */
 447                                                 in_vain = 0;
 448                                         } else if (!args->stateless_rpc
 449                                                    || ack != ACK_common)
 450                                                 in_vain = 0;
 451                                         retval = 0;
 452                                         got_continue = 1;
 453                                         if (ack == ACK_ready)
 454                                                 got_ready = 1;
 455                                         break;
 456                                         }
 457                                 }
 458                         } while (ack);
 459                         flushes--;
 460                         if (got_continue && MAX_IN_VAIN < in_vain) {
 461                                 print_verbose(args, _("giving up"));
 462                                 break; /* give up */
 463                         }
 464                         if (got_ready)
 465                                 break;
 466                 }
 467         }
 468 done:
 469         if (!got_ready || !no_done) {
 470                 packet_buf_write(&req_buf, "done\n");
 471                 send_request(args, fd[1], &req_buf);
 472         }
 473         print_verbose(args, _("done"));
 474         if (retval != 0) {
 475                 multi_ack = 0;
 476                 flushes++;
 477         }
 478         strbuf_release(&req_buf);
 479
 480         if (!got_ready || !no_done)
 481                 consume_shallow_list(args, &reader);
 482         while (flushes || multi_ack) {
 483                 int ack = get_ack(&reader, result_oid);
 484                 if (ack) {
 485                         print_verbose(args, _("got %s (%d) %s"), "ack",
 486                                       ack, oid_to_hex(result_oid));
 487                         if (ack == ACK)
 488                                 return 0;
 489                         multi_ack = 1;
 490                         continue;
 491                 }
 492                 flushes--;
 493         }
 494         /* it is no error to fetch into a completely empty repo */
 495         return count ? retval : 0;
 496 }
 497
 498 static struct commit_list *complete;
 499
 500 static int mark_complete(const struct object_id *oid)
 501 {
 502         struct object *o = parse_object(the_repository, oid);
 503
 504         while (o && o->type == OBJ_TAG) {
 505                 struct tag *t = (struct tag *) o;
 506                 if (!t->tagged)
 507                         break; /* broken repository */
 508                 o->flags |= COMPLETE;
 509                 o = parse_object(the_repository, &t->tagged->oid);
 510         }
 511         if (o && o->type == OBJ_COMMIT) {
 512                 struct commit *commit = (struct commit *)o;
 513                 if (!(commit->object.flags & COMPLETE)) {
 514                         commit->object.flags |= COMPLETE;
 515                         commit_list_insert(commit, &complete);
 516                 }
 517         }
 518         return 0;
 519 }
 520
 521 static int mark_complete_oid(const char *refname, const struct object_id *oid,
 522                              int flag, void *cb_data)
 523 {
 524         return mark_complete(oid);
 525 }
 526
 527 static void mark_recent_complete_commits(struct fetch_pack_args *args,
 528                                          timestamp_t cutoff)
 529 {
 530         while (complete && cutoff <= complete->item->date) {
 531                 print_verbose(args, _("Marking %s as complete"),
 532                               oid_to_hex(&complete->item->object.oid));
 533                 pop_most_recent_commit(&complete, COMPLETE);
 534         }
 535 }
 536
 537 static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
 538 {
 539         for (; refs; refs = refs->next)
 540                 oidset_insert(oids, &refs->old_oid);
 541 }
 542
 543 static int is_unmatched_ref(const struct ref *ref)
 544 {
 545         struct object_id oid;
 546         const char *p;
 547         return  ref->match_status == REF_NOT_MATCHED &&
 548                 !parse_oid_hex(ref->name, &oid, &p) &&
 549                 *p == '\0' &&
 550                 oideq(&oid, &ref->old_oid);
 551 }
 552
 553 static void filter_refs(struct fetch_pack_args *args,
 554                         struct ref **refs,
 555                         struct ref **sought, int nr_sought)
 556 {
 557         struct ref *newlist = NULL;
 558         struct ref **newtail = &newlist;
 559         struct ref *unmatched = NULL;
 560         struct ref *ref, *next;
 561         struct oidset tip_oids = OIDSET_INIT;
 562         int i;
 563         int strict = !(allow_unadvertised_object_request &
 564                        (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1));
 565
 566         i = 0;
 567         for (ref = *refs; ref; ref = next) {
 568                 int keep = 0;
 569                 next = ref->next;
 570
 571                 if (starts_with(ref->name, "refs/") &&
 572                     check_refname_format(ref->name, 0)) {
 573                         /*
 574                          * trash or a peeled value; do not even add it to
 575                          * unmatched list
 576                          */
 577                         free_one_ref(ref);
 578                         continue;
 579                 } else {
 580                         while (i < nr_sought) {
 581                                 int cmp = strcmp(ref->name, sought[i]->name);
 582                                 if (cmp < 0)
 583                                         break; /* definitely do not have it */
 584                                 else if (cmp == 0) {
 585                                         keep = 1; /* definitely have it */
 586                                         sought[i]->match_status = REF_MATCHED;
 587                                 }
 588                                 i++;
 589                         }
 590
 591                         if (!keep && args->fetch_all &&
 592                             (!args->deepen || !starts_with(ref->name, "refs/tags/")))
 593                                 keep = 1;
 594                 }
 595
 596                 if (keep) {
 597                         *newtail = ref;
 598                         ref->next = NULL;
 599                         newtail = &ref->next;
 600                 } else {
 601                         ref->next = unmatched;
 602                         unmatched = ref;
 603                 }
 604         }
 605
 606         if (strict) {
 607                 for (i = 0; i < nr_sought; i++) {
 608                         ref = sought[i];
 609                         if (!is_unmatched_ref(ref))
 610                                 continue;
 611
 612                         add_refs_to_oidset(&tip_oids, unmatched);
 613                         add_refs_to_oidset(&tip_oids, newlist);
 614                         break;
 615                 }
 616         }
 617
 618         /* Append unmatched requests to the list */
 619         for (i = 0; i < nr_sought; i++) {
 620                 ref = sought[i];
 621                 if (!is_unmatched_ref(ref))
 622                         continue;
 623
 624                 if (!strict || oidset_contains(&tip_oids, &ref->old_oid)) {
 625                         ref->match_status = REF_MATCHED;
 626                         *newtail = copy_ref(ref);
 627                         newtail = &(*newtail)->next;
 628                 } else {
 629                         ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 630                 }
 631         }
 632
 633         oidset_clear(&tip_oids);
 634         free_refs(unmatched);
 635
 636         *refs = newlist;
 637 }
 638
 639 static void mark_alternate_complete(struct fetch_negotiator *unused,
 640                                     struct object *obj)
 641 {
 642         mark_complete(&obj->oid);
 643 }
 644
 645 struct loose_object_iter {
 646         struct oidset *loose_object_set;
 647         struct ref *refs;
 648 };
 649
 650 /*
 651  * Mark recent commits available locally and reachable from a local ref as
 652  * COMPLETE. If args->no_dependents is false, also mark COMPLETE remote refs as
 653  * COMMON_REF (otherwise, we are not planning to participate in negotiation, and
 654  * thus do not need COMMON_REF marks).
 655  *
 656  * The cutoff time for recency is determined by this heuristic: it is the
 657  * earliest commit time of the objects in refs that are commits and that we know
 658  * the commit time of.
 659  */
 660 static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
 661                                          struct fetch_pack_args *args,
 662                                          struct ref **refs)
 663 {
 664         struct ref *ref;
 665         int old_save_commit_buffer = save_commit_buffer;
 666         timestamp_t cutoff = 0;
 667
 668         save_commit_buffer = 0;
 669
 670         for (ref = *refs; ref; ref = ref->next) {
 671                 struct object *o;
 672
 673                 if (!has_object_file_with_flags(&ref->old_oid,
 674                                                 OBJECT_INFO_QUICK))
 675                         continue;
 676                 o = parse_object(the_repository, &ref->old_oid);
 677                 if (!o)
 678                         continue;
 679
 680                 /* We already have it -- which may mean that we were
 681                  * in sync with the other side at some time after
 682                  * that (it is OK if we guess wrong here).
 683                  */
 684                 if (o->type == OBJ_COMMIT) {
 685                         struct commit *commit = (struct commit *)o;
 686                         if (!cutoff || cutoff < commit->date)
 687                                 cutoff = commit->date;
 688                 }
 689         }
 690
 691         if (!args->deepen) {
 692                 for_each_ref(mark_complete_oid, NULL);
 693                 for_each_cached_alternate(NULL, mark_alternate_complete);
 694                 commit_list_sort_by_date(&complete);
 695                 if (cutoff)
 696                         mark_recent_complete_commits(args, cutoff);
 697         }
 698
 699         /*
 700          * Mark all complete remote refs as common refs.
 701          * Don't mark them common yet; the server has to be told so first.
 702          */
 703         for (ref = *refs; ref; ref = ref->next) {
 704                 struct object *o = deref_tag(the_repository,
 705                                              lookup_object(the_repository,
 706                                              &ref->old_oid),
 707                                              NULL, 0);
 708
 709                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
 710                         continue;
 711
 712                 negotiator->known_common(negotiator,
 713                                          (struct commit *)o);
 714         }
 715
 716         save_commit_buffer = old_save_commit_buffer;
 717 }
 718
 719 /*
 720  * Returns 1 if every object pointed to by the given remote refs is available
 721  * locally and reachable from a local ref, and 0 otherwise.
 722  */
 723 static int everything_local(struct fetch_pack_args *args,
 724                             struct ref **refs)
 725 {
 726         struct ref *ref;
 727         int retval;
 728
 729         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
 730                 const struct object_id *remote = &ref->old_oid;
 731                 struct object *o;
 732
 733                 o = lookup_object(the_repository, remote);
 734                 if (!o || !(o->flags & COMPLETE)) {
 735                         retval = 0;
 736                         print_verbose(args, "want %s (%s)", oid_to_hex(remote),
 737                                       ref->name);
 738                         continue;
 739                 }
 740                 print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 741                               ref->name);
 742         }
 743
 744         return retval;
 745 }
 746
 747 static int sideband_demux(int in, int out, void *data)
 748 {
 749         int *xd = data;
 750         int ret;
 751
 752         ret = recv_sideband("fetch-pack", xd[0], out);
 753         close(out);
 754         return ret;
 755 }
 756
 757 static int get_pack(struct fetch_pack_args *args,
 758                     int xd[2], char **pack_lockfile)
 759 {
 760         struct async demux;
 761         int do_keep = args->keep_pack;
 762         const char *cmd_name;
 763         struct pack_header header;
 764         int pass_header = 0;
 765         struct child_process cmd = CHILD_PROCESS_INIT;
 766         int ret;
 767
 768         memset(&demux, 0, sizeof(demux));
 769         if (use_sideband) {
 770                 /* xd[] is talking with upload-pack; subprocess reads from
 771                  * xd[0], spits out band#2 to stderr, and feeds us band#1
 772                  * through demux->out.
 773                  */
 774                 demux.proc = sideband_demux;
 775                 demux.data = xd;
 776                 demux.out = -1;
 777                 demux.isolate_sigpipe = 1;
 778                 if (start_async(&demux))
 779                         die(_("fetch-pack: unable to fork off sideband demultiplexer"));
 780         }
 781         else
 782                 demux.out = xd[0];
 783
 784         if (!args->keep_pack && unpack_limit) {
 785
 786                 if (read_pack_header(demux.out, &header))
 787                         die(_("protocol error: bad pack header"));
 788                 pass_header = 1;
 789                 if (ntohl(header.hdr_entries) < unpack_limit)
 790                         do_keep = 0;
 791                 else
 792                         do_keep = 1;
 793         }
 794
 795         if (alternate_shallow_file) {
 796                 argv_array_push(&cmd.args, "--shallow-file");
 797                 argv_array_push(&cmd.args, alternate_shallow_file);
 798         }
 799
 800         if (do_keep || args->from_promisor) {
 801                 if (pack_lockfile)
 802                         cmd.out = -1;
 803                 cmd_name = "index-pack";
 804                 argv_array_push(&cmd.args, cmd_name);
 805                 argv_array_push(&cmd.args, "--stdin");
 806                 if (!args->quiet && !args->no_progress)
 807                         argv_array_push(&cmd.args, "-v");
 808                 if (args->use_thin_pack)
 809                         argv_array_push(&cmd.args, "--fix-thin");
 810                 if (do_keep && (args->lock_pack || unpack_limit)) {
 811                         char hostname[HOST_NAME_MAX + 1];
 812                         if (xgethostname(hostname, sizeof(hostname)))
 813                                 xsnprintf(hostname, sizeof(hostname), "localhost");
 814                         argv_array_pushf(&cmd.args,
 815                                         "--keep=fetch-pack %"PRIuMAX " on %s",
 816                                         (uintmax_t)getpid(), hostname);
 817                 }
 818                 if (args->check_self_contained_and_connected)
 819                         argv_array_push(&cmd.args, "--check-self-contained-and-connected");
 820                 if (args->from_promisor)
 821                         argv_array_push(&cmd.args, "--promisor");
 822         }
 823         else {
 824                 cmd_name = "unpack-objects";
 825                 argv_array_push(&cmd.args, cmd_name);
 826                 if (args->quiet || args->no_progress)
 827                         argv_array_push(&cmd.args, "-q");
 828                 args->check_self_contained_and_connected = 0;
 829         }
 830
 831         if (pass_header)
 832                 argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
 833                                  ntohl(header.hdr_version),
 834                                  ntohl(header.hdr_entries));
 835         if (fetch_fsck_objects >= 0
 836             ? fetch_fsck_objects
 837             : transfer_fsck_objects >= 0
 838             ? transfer_fsck_objects
 839             : 0) {
 840                 if (args->from_promisor)
 841                         /*
 842                          * We cannot use --strict in index-pack because it
 843                          * checks both broken objects and links, but we only
 844                          * want to check for broken objects.
 845                          */
 846                         argv_array_push(&cmd.args, "--fsck-objects");
 847                 else
 848                         argv_array_pushf(&cmd.args, "--strict%s",
 849                                          fsck_msg_types.buf);
 850         }
 851
 852         cmd.in = demux.out;
 853         cmd.git_cmd = 1;
 854         if (start_command(&cmd))
 855                 die(_("fetch-pack: unable to fork off %s"), cmd_name);
 856         if (do_keep && pack_lockfile) {
 857                 *pack_lockfile = index_pack_lockfile(cmd.out);
 858                 close(cmd.out);
 859         }
 860
 861         if (!use_sideband)
 862                 /* Closed by start_command() */
 863                 xd[0] = -1;
 864
 865         ret = finish_command(&cmd);
 866         if (!ret || (args->check_self_contained_and_connected && ret == 1))
 867                 args->self_contained_and_connected =
 868                         args->check_self_contained_and_connected &&
 869                         ret == 0;
 870         else
 871                 die(_("%s failed"), cmd_name);
 872         if (use_sideband && finish_async(&demux))
 873                 die(_("error in sideband demultiplexer"));
 874         return 0;
 875 }
 876
 877 static int cmp_ref_by_name(const void *a_, const void *b_)
 878 {
 879         const struct ref *a = *((const struct ref **)a_);
 880         const struct ref *b = *((const struct ref **)b_);
 881         return strcmp(a->name, b->name);
 882 }
 883
 884 static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 885                                  int fd[2],
 886                                  const struct ref *orig_ref,
 887                                  struct ref **sought, int nr_sought,
 888                                  struct shallow_info *si,
 889                                  char **pack_lockfile)
 890 {
 891         struct repository *r = the_repository;
 892         struct ref *ref = copy_ref_list(orig_ref);
 893         struct object_id oid;
 894         const char *agent_feature;
 895         int agent_len;
 896         struct fetch_negotiator negotiator;
 897         fetch_negotiator_init(r, &negotiator);
 898
 899         sort_ref_list(&ref, ref_compare_name);
 900         QSORT(sought, nr_sought, cmp_ref_by_name);
 901
 902         if ((agent_feature = server_feature_value("agent", &agent_len))) {
 903                 agent_supported = 1;
 904                 if (agent_len)
 905                         print_verbose(args, _("Server version is %.*s"),
 906                                       agent_len, agent_feature);
 907         }
 908
 909         if (server_supports("shallow"))
 910                 print_verbose(args, _("Server supports %s"), "shallow");
 911         else if (args->depth > 0 || is_repository_shallow(r))
 912                 die(_("Server does not support shallow clients"));
 913         if (args->depth > 0 || args->deepen_since || args->deepen_not)
 914                 args->deepen = 1;
 915         if (server_supports("multi_ack_detailed")) {
 916                 print_verbose(args, _("Server supports %s"), "multi_ack_detailed");
 917                 multi_ack = 2;
 918                 if (server_supports("no-done")) {
 919                         print_verbose(args, _("Server supports %s"), "no-done");
 920                         if (args->stateless_rpc)
 921                                 no_done = 1;
 922                 }
 923         }
 924         else if (server_supports("multi_ack")) {
 925                 print_verbose(args, _("Server supports %s"), "multi_ack");
 926                 multi_ack = 1;
 927         }
 928         if (server_supports("side-band-64k")) {
 929                 print_verbose(args, _("Server supports %s"), "side-band-64k");
 930                 use_sideband = 2;
 931         }
 932         else if (server_supports("side-band")) {
 933                 print_verbose(args, _("Server supports %s"), "side-band");
 934                 use_sideband = 1;
 935         }
 936         if (server_supports("allow-tip-sha1-in-want")) {
 937                 print_verbose(args, _("Server supports %s"), "allow-tip-sha1-in-want");
 938                 allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 939         }
 940         if (server_supports("allow-reachable-sha1-in-want")) {
 941                 print_verbose(args, _("Server supports %s"), "allow-reachable-sha1-in-want");
 942                 allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 943         }
 944         if (server_supports("thin-pack"))
 945                 print_verbose(args, _("Server supports %s"), "thin-pack");
 946         else
 947                 args->use_thin_pack = 0;
 948         if (server_supports("no-progress"))
 949                 print_verbose(args, _("Server supports %s"), "no-progress");
 950         else
 951                 args->no_progress = 0;
 952         if (server_supports("include-tag"))
 953                 print_verbose(args, _("Server supports %s"), "include-tag");
 954         else
 955                 args->include_tag = 0;
 956         if (server_supports("ofs-delta"))
 957                 print_verbose(args, _("Server supports %s"), "ofs-delta");
 958         else
 959                 prefer_ofs_delta = 0;
 960
 961         if (server_supports("filter")) {
 962                 server_supports_filtering = 1;
 963                 print_verbose(args, _("Server supports %s"), "filter");
 964         } else if (args->filter_options.choice) {
 965                 warning("filtering not recognized by server, ignoring");
 966         }
 967
 968         if (server_supports("deepen-since")) {
 969                 print_verbose(args, _("Server supports %s"), "deepen-since");
 970                 deepen_since_ok = 1;
 971         } else if (args->deepen_since)
 972                 die(_("Server does not support --shallow-since"));
 973         if (server_supports("deepen-not")) {
 974                 print_verbose(args, _("Server supports %s"), "deepen-not");
 975                 deepen_not_ok = 1;
 976         } else if (args->deepen_not)
 977                 die(_("Server does not support --shallow-exclude"));
 978         if (server_supports("deepen-relative"))
 979                 print_verbose(args, _("Server supports %s"), "deepen-relative");
 980         else if (args->deepen_relative)
 981                 die(_("Server does not support --deepen"));
 982
 983         if (!args->no_dependents) {
 984                 mark_complete_and_common_ref(&negotiator, args, &ref);
 985                 filter_refs(args, &ref, sought, nr_sought);
 986                 if (everything_local(args, &ref)) {
 987                         packet_flush(fd[1]);
 988                         goto all_done;
 989                 }
 990         } else {
 991                 filter_refs(args, &ref, sought, nr_sought);
 992         }
 993         if (find_common(&negotiator, args, fd, &oid, ref) < 0)
 994                 if (!args->keep_pack)
 995                         /* When cloning, it is not unusual to have
 996                          * no common commit.
 997                          */
 998                         warning(_("no common commits"));
 999
1000         if (args->stateless_rpc)
1001                 packet_flush(fd[1]);
1002         if (args->deepen)
1003                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
1004                                         NULL);
1005         else if (si->nr_ours || si->nr_theirs)
1006                 alternate_shallow_file = setup_temporary_shallow(si->shallow);
1007         else
1008                 alternate_shallow_file = NULL;
1009         if (get_pack(args, fd, pack_lockfile))
1010                 die(_("git fetch-pack: fetch failed."));
1011
1012  all_done:
1013         negotiator.release(&negotiator);
1014         return ref;
1015 }
1016
1017 static void add_shallow_requests(struct strbuf *req_buf,
1018                                  const struct fetch_pack_args *args)
1019 {
1020         if (is_repository_shallow(the_repository))
1021                 write_shallow_commits(req_buf, 1, NULL);
1022         if (args->depth > 0)
1023                 packet_buf_write(req_buf, "deepen %d", args->depth);
1024         if (args->deepen_since) {
1025                 timestamp_t max_age = approxidate(args->deepen_since);
1026                 packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
1027         }
1028         if (args->deepen_not) {
1029                 int i;
1030                 for (i = 0; i < args->deepen_not->nr; i++) {
1031                         struct string_list_item *s = args->deepen_not->items + i;
1032                         packet_buf_write(req_buf, "deepen-not %s", s->string);
1033                 }
1034         }
1035         if (args->deepen_relative)
1036                 packet_buf_write(req_buf, "deepen-relative\n");
1037 }
1038
1039 static void add_wants(int no_dependents, const struct ref *wants, struct strbuf *req_buf)
1040 {
1041         int use_ref_in_want = server_supports_feature("fetch", "ref-in-want", 0);
1042
1043         for ( ; wants ; wants = wants->next) {
1044                 const struct object_id *remote = &wants->old_oid;
1045                 struct object *o;
1046
1047                 /*
1048                  * If that object is complete (i.e. it is an ancestor of a
1049                  * local ref), we tell them we have it but do not have to
1050                  * tell them about its ancestors, which they already know
1051                  * about.
1052                  *
1053                  * We use lookup_object here because we are only
1054                  * interested in the case we *know* the object is
1055                  * reachable and we have already scanned it.
1056                  *
1057                  * Do this only if args->no_dependents is false (if it is true,
1058                  * we cannot trust the object flags).
1059                  */
1060                 if (!no_dependents &&
1061                     ((o = lookup_object(the_repository, remote)) != NULL) &&
1062                     (o->flags & COMPLETE)) {
1063                         continue;
1064                 }
1065
1066                 if (!use_ref_in_want || wants->exact_oid)
1067                         packet_buf_write(req_buf, "want %s\n", oid_to_hex(remote));
1068                 else
1069                         packet_buf_write(req_buf, "want-ref %s\n", wants->name);
1070         }
1071 }
1072
1073 static void add_common(struct strbuf *req_buf, struct oidset *common)
1074 {
1075         struct oidset_iter iter;
1076         const struct object_id *oid;
1077         oidset_iter_init(common, &iter);
1078
1079         while ((oid = oidset_iter_next(&iter))) {
1080                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1081         }
1082 }
1083
1084 static int add_haves(struct fetch_negotiator *negotiator,
1085                      struct strbuf *req_buf,
1086                      int *haves_to_send, int *in_vain)
1087 {
1088         int ret = 0;
1089         int haves_added = 0;
1090         const struct object_id *oid;
1091
1092         while ((oid = negotiator->next(negotiator))) {
1093                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1094                 if (++haves_added >= *haves_to_send)
1095                         break;
1096         }
1097
1098         *in_vain += haves_added;
1099         if (!haves_added || *in_vain >= MAX_IN_VAIN) {
1100                 /* Send Done */
1101                 packet_buf_write(req_buf, "done\n");
1102                 ret = 1;
1103         }
1104
1105         /* Increase haves to send on next round */
1106         *haves_to_send = next_flush(1, *haves_to_send);
1107
1108         return ret;
1109 }
1110
1111 static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
1112                               struct fetch_pack_args *args,
1113                               const struct ref *wants, struct oidset *common,
1114                               int *haves_to_send, int *in_vain,
1115                               int sideband_all)
1116 {
1117         int ret = 0;
1118         struct strbuf req_buf = STRBUF_INIT;
1119
1120         if (server_supports_v2("fetch", 1))
1121                 packet_buf_write(&req_buf, "command=fetch");
1122         if (server_supports_v2("agent", 0))
1123                 packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
1124         if (args->server_options && args->server_options->nr &&
1125             server_supports_v2("server-option", 1)) {
1126                 int i;
1127                 for (i = 0; i < args->server_options->nr; i++)
1128                         packet_buf_write(&req_buf, "server-option=%s",
1129                                          args->server_options->items[i].string);
1130         }
1131
1132         packet_buf_delim(&req_buf);
1133         if (args->use_thin_pack)
1134                 packet_buf_write(&req_buf, "thin-pack");
1135         if (args->no_progress)
1136                 packet_buf_write(&req_buf, "no-progress");
1137         if (args->include_tag)
1138                 packet_buf_write(&req_buf, "include-tag");
1139         if (prefer_ofs_delta)
1140                 packet_buf_write(&req_buf, "ofs-delta");
1141         if (sideband_all)
1142                 packet_buf_write(&req_buf, "sideband-all");
1143
1144         /* Add shallow-info and deepen request */
1145         if (server_supports_feature("fetch", "shallow", 0))
1146                 add_shallow_requests(&req_buf, args);
1147         else if (is_repository_shallow(the_repository) || args->deepen)
1148                 die(_("Server does not support shallow requests"));
1149
1150         /* Add filter */
1151         if (server_supports_feature("fetch", "filter", 0) &&
1152             args->filter_options.choice) {
1153                 const char *spec =
1154                         expand_list_objects_filter_spec(&args->filter_options);
1155                 print_verbose(args, _("Server supports filter"));
1156                 packet_buf_write(&req_buf, "filter %s", spec);
1157         } else if (args->filter_options.choice) {
1158                 warning("filtering not recognized by server, ignoring");
1159         }
1160
1161         /* add wants */
1162         add_wants(args->no_dependents, wants, &req_buf);
1163
1164         if (args->no_dependents) {
1165                 packet_buf_write(&req_buf, "done");
1166                 ret = 1;
1167         } else {
1168                 /* Add all of the common commits we've found in previous rounds */
1169                 add_common(&req_buf, common);
1170
1171                 /* Add initial haves */
1172                 ret = add_haves(negotiator, &req_buf, haves_to_send, in_vain);
1173         }
1174
1175         /* Send request */
1176         packet_buf_flush(&req_buf);
1177         if (write_in_full(fd_out, req_buf.buf, req_buf.len) < 0)
1178                 die_errno(_("unable to write request to remote"));
1179
1180         strbuf_release(&req_buf);
1181         return ret;
1182 }
1183
1184 /*
1185  * Processes a section header in a server's response and checks if it matches
1186  * `section`.  If the value of `peek` is 1, the header line will be peeked (and
1187  * not consumed); if 0, the line will be consumed and the function will die if
1188  * the section header doesn't match what was expected.
1189  */
1190 static int process_section_header(struct packet_reader *reader,
1191                                   const char *section, int peek)
1192 {
1193         int ret;
1194
1195         if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
1196                 die(_("error reading section header '%s'"), section);
1197
1198         ret = !strcmp(reader->line, section);
1199
1200         if (!peek) {
1201                 if (!ret)
1202                         die(_("expected '%s', received '%s'"),
1203                             section, reader->line);
1204                 packet_reader_read(reader);
1205         }
1206
1207         return ret;
1208 }
1209
1210 static int process_acks(struct fetch_negotiator *negotiator,
1211                         struct packet_reader *reader,
1212                         struct oidset *common)
1213 {
1214         /* received */
1215         int received_ready = 0;
1216         int received_ack = 0;
1217
1218         process_section_header(reader, "acknowledgments", 0);
1219         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1220                 const char *arg;
1221
1222                 if (!strcmp(reader->line, "NAK"))
1223                         continue;
1224
1225                 if (skip_prefix(reader->line, "ACK ", &arg)) {
1226                         struct object_id oid;
1227                         if (!get_oid_hex(arg, &oid)) {
1228                                 struct commit *commit;
1229                                 oidset_insert(common, &oid);
1230                                 commit = lookup_commit(the_repository, &oid);
1231                                 negotiator->ack(negotiator, commit);
1232                         }
1233                         continue;
1234                 }
1235
1236                 if (!strcmp(reader->line, "ready")) {
1237                         received_ready = 1;
1238                         continue;
1239                 }
1240
1241                 die(_("unexpected acknowledgment line: '%s'"), reader->line);
1242         }
1243
1244         if (reader->status != PACKET_READ_FLUSH &&
1245             reader->status != PACKET_READ_DELIM)
1246                 die(_("error processing acks: %d"), reader->status);
1247
1248         /*
1249          * If an "acknowledgments" section is sent, a packfile is sent if and
1250          * only if "ready" was sent in this section. The other sections
1251          * ("shallow-info" and "wanted-refs") are sent only if a packfile is
1252          * sent. Therefore, a DELIM is expected if "ready" is sent, and a FLUSH
1253          * otherwise.
1254          */
1255         if (received_ready && reader->status != PACKET_READ_DELIM)
1256                 die(_("expected packfile to be sent after 'ready'"));
1257         if (!received_ready && reader->status != PACKET_READ_FLUSH)
1258                 die(_("expected no other sections to be sent after no 'ready'"));
1259
1260         /* return 0 if no common, 1 if there are common, or 2 if ready */
1261         return received_ready ? 2 : (received_ack ? 1 : 0);
1262 }
1263
1264 static void receive_shallow_info(struct fetch_pack_args *args,
1265                                  struct packet_reader *reader,
1266                                  struct oid_array *shallows,
1267                                  struct shallow_info *si)
1268 {
1269         int unshallow_received = 0;
1270
1271         process_section_header(reader, "shallow-info", 0);
1272         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1273                 const char *arg;
1274                 struct object_id oid;
1275
1276                 if (skip_prefix(reader->line, "shallow ", &arg)) {
1277                         if (get_oid_hex(arg, &oid))
1278                                 die(_("invalid shallow line: %s"), reader->line);
1279                         oid_array_append(shallows, &oid);
1280                         continue;
1281                 }
1282                 if (skip_prefix(reader->line, "unshallow ", &arg)) {
1283                         if (get_oid_hex(arg, &oid))
1284                                 die(_("invalid unshallow line: %s"), reader->line);
1285                         if (!lookup_object(the_repository, &oid))
1286                                 die(_("object not found: %s"), reader->line);
1287                         /* make sure that it is parsed as shallow */
1288                         if (!parse_object(the_repository, &oid))
1289                                 die(_("error in object: %s"), reader->line);
1290                         if (unregister_shallow(&oid))
1291                                 die(_("no shallow found: %s"), reader->line);
1292                         unshallow_received = 1;
1293                         continue;
1294                 }
1295                 die(_("expected shallow/unshallow, got %s"), reader->line);
1296         }
1297
1298         if (reader->status != PACKET_READ_FLUSH &&
1299             reader->status != PACKET_READ_DELIM)
1300                 die(_("error processing shallow info: %d"), reader->status);
1301
1302         if (args->deepen || unshallow_received) {
1303                 /*
1304                  * Treat these as shallow lines caused by our depth settings.
1305                  * In v0, these lines cannot cause refs to be rejected; do the
1306                  * same.
1307                  */
1308                 int i;
1309
1310                 for (i = 0; i < shallows->nr; i++)
1311                         register_shallow(the_repository, &shallows->oid[i]);
1312                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
1313                                         NULL);
1314                 args->deepen = 1;
1315         } else if (shallows->nr) {
1316                 /*
1317                  * Treat these as shallow lines caused by the remote being
1318                  * shallow. In v0, remote refs that reach these objects are
1319                  * rejected (unless --update-shallow is set); do the same.
1320                  */
1321                 prepare_shallow_info(si, shallows);
1322                 if (si->nr_ours || si->nr_theirs)
1323                         alternate_shallow_file =
1324                                 setup_temporary_shallow(si->shallow);
1325                 else
1326                         alternate_shallow_file = NULL;
1327         } else {
1328                 alternate_shallow_file = NULL;
1329         }
1330 }
1331
1332 static int cmp_name_ref(const void *name, const void *ref)
1333 {
1334         return strcmp(name, (*(struct ref **)ref)->name);
1335 }
1336
1337 static void receive_wanted_refs(struct packet_reader *reader,
1338                                 struct ref **sought, int nr_sought)
1339 {
1340         process_section_header(reader, "wanted-refs", 0);
1341         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1342                 struct object_id oid;
1343                 const char *end;
1344                 struct ref **found;
1345
1346                 if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ')
1347                         die(_("expected wanted-ref, got '%s'"), reader->line);
1348
1349                 found = bsearch(end, sought, nr_sought, sizeof(*sought),
1350                                 cmp_name_ref);
1351                 if (!found)
1352                         die(_("unexpected wanted-ref: '%s'"), reader->line);
1353                 oidcpy(&(*found)->old_oid, &oid);
1354         }
1355
1356         if (reader->status != PACKET_READ_DELIM)
1357                 die(_("error processing wanted refs: %d"), reader->status);
1358 }
1359
1360 enum fetch_state {
1361         FETCH_CHECK_LOCAL = 0,
1362         FETCH_SEND_REQUEST,
1363         FETCH_PROCESS_ACKS,
1364         FETCH_GET_PACK,
1365         FETCH_DONE,
1366 };
1367
1368 static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
1369                                     int fd[2],
1370                                     const struct ref *orig_ref,
1371                                     struct ref **sought, int nr_sought,
1372                                     struct oid_array *shallows,
1373                                     struct shallow_info *si,
1374                                     char **pack_lockfile)
1375 {
1376         struct repository *r = the_repository;
1377         struct ref *ref = copy_ref_list(orig_ref);
1378         enum fetch_state state = FETCH_CHECK_LOCAL;
1379         struct oidset common = OIDSET_INIT;
1380         struct packet_reader reader;
1381         int in_vain = 0;
1382         int haves_to_send = INITIAL_FLUSH;
1383         struct fetch_negotiator negotiator;
1384         fetch_negotiator_init(r, &negotiator);
1385         packet_reader_init(&reader, fd[0], NULL, 0,
1386                            PACKET_READ_CHOMP_NEWLINE |
1387                            PACKET_READ_DIE_ON_ERR_PACKET);
1388         if (git_env_bool("GIT_TEST_SIDEBAND_ALL", 1) &&
1389             server_supports_feature("fetch", "sideband-all", 0)) {
1390                 reader.use_sideband = 1;
1391                 reader.me = "fetch-pack";
1392         }
1393
1394         while (state != FETCH_DONE) {
1395                 switch (state) {
1396                 case FETCH_CHECK_LOCAL:
1397                         sort_ref_list(&ref, ref_compare_name);
1398                         QSORT(sought, nr_sought, cmp_ref_by_name);
1399
1400                         /* v2 supports these by default */
1401                         allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
1402                         use_sideband = 2;
1403                         if (args->depth > 0 || args->deepen_since || args->deepen_not)
1404                                 args->deepen = 1;
1405
1406                         /* Filter 'ref' by 'sought' and those that aren't local */
1407                         if (!args->no_dependents) {
1408                                 mark_complete_and_common_ref(&negotiator, args, &ref);
1409                                 filter_refs(args, &ref, sought, nr_sought);
1410                                 if (everything_local(args, &ref))
1411                                         state = FETCH_DONE;
1412                                 else
1413                                         state = FETCH_SEND_REQUEST;
1414
1415                                 mark_tips(&negotiator, args->negotiation_tips);
1416                                 for_each_cached_alternate(&negotiator,
1417                                                           insert_one_alternate_object);
1418                         } else {
1419                                 filter_refs(args, &ref, sought, nr_sought);
1420                                 state = FETCH_SEND_REQUEST;
1421                         }
1422                         break;
1423                 case FETCH_SEND_REQUEST:
1424                         if (send_fetch_request(&negotiator, fd[1], args, ref,
1425                                                &common,
1426                                                &haves_to_send, &in_vain,
1427                                                reader.use_sideband))
1428                                 state = FETCH_GET_PACK;
1429                         else
1430                                 state = FETCH_PROCESS_ACKS;
1431                         break;
1432                 case FETCH_PROCESS_ACKS:
1433                         /* Process ACKs/NAKs */
1434                         switch (process_acks(&negotiator, &reader, &common)) {
1435                         case 2:
1436                                 state = FETCH_GET_PACK;
1437                                 break;
1438                         case 1:
1439                                 in_vain = 0;
1440                                 /* fallthrough */
1441                         default:
1442                                 state = FETCH_SEND_REQUEST;
1443                                 break;
1444                         }
1445                         break;
1446                 case FETCH_GET_PACK:
1447                         /* Check for shallow-info section */
1448                         if (process_section_header(&reader, "shallow-info", 1))
1449                                 receive_shallow_info(args, &reader, shallows, si);
1450
1451                         if (process_section_header(&reader, "wanted-refs", 1))
1452                                 receive_wanted_refs(&reader, sought, nr_sought);
1453
1454                         /* get the pack */
1455                         process_section_header(&reader, "packfile", 0);
1456                         if (get_pack(args, fd, pack_lockfile))
1457                                 die(_("git fetch-pack: fetch failed."));
1458
1459                         state = FETCH_DONE;
1460                         break;
1461                 case FETCH_DONE:
1462                         continue;
1463                 }
1464         }
1465
1466         negotiator.release(&negotiator);
1467         oidset_clear(&common);
1468         return ref;
1469 }
1470
1471 static int fetch_pack_config_cb(const char *var, const char *value, void *cb)
1472 {
1473         if (strcmp(var, "fetch.fsck.skiplist") == 0) {
1474                 const char *path;
1475
1476                 if (git_config_pathname(&path, var, value))
1477                         return 1;
1478                 strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
1479                         fsck_msg_types.len ? ',' : '=', path);
1480                 free((char *)path);
1481                 return 0;
1482         }
1483
1484         if (skip_prefix(var, "fetch.fsck.", &var)) {
1485                 if (is_valid_msg_type(var, value))
1486                         strbuf_addf(&fsck_msg_types, "%c%s=%s",
1487                                 fsck_msg_types.len ? ',' : '=', var, value);
1488                 else
1489                         warning("Skipping unknown msg id '%s'", var);
1490                 return 0;
1491         }
1492
1493         return git_default_config(var, value, cb);
1494 }
1495
1496 static void fetch_pack_config(void)
1497 {
1498         git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1499         git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1500         git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1501         git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1502         git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1503
1504         git_config(fetch_pack_config_cb, NULL);
1505 }
1506
1507 static void fetch_pack_setup(void)
1508 {
1509         static int did_setup;
1510         if (did_setup)
1511                 return;
1512         fetch_pack_config();
1513         if (0 <= transfer_unpack_limit)
1514                 unpack_limit = transfer_unpack_limit;
1515         else if (0 <= fetch_unpack_limit)
1516                 unpack_limit = fetch_unpack_limit;
1517         did_setup = 1;
1518 }
1519
1520 static int remove_duplicates_in_refs(struct ref **ref, int nr)
1521 {
1522         struct string_list names = STRING_LIST_INIT_NODUP;
1523         int src, dst;
1524
1525         for (src = dst = 0; src < nr; src++) {
1526                 struct string_list_item *item;
1527                 item = string_list_insert(&names, ref[src]->name);
1528                 if (item->util)
1529                         continue; /* already have it */
1530                 item->util = ref[src];
1531                 if (src != dst)
1532                         ref[dst] = ref[src];
1533                 dst++;
1534         }
1535         for (src = dst; src < nr; src++)
1536                 ref[src] = NULL;
1537         string_list_clear(&names, 0);
1538         return dst;
1539 }
1540
1541 static void update_shallow(struct fetch_pack_args *args,
1542                            struct ref **sought, int nr_sought,
1543                            struct shallow_info *si)
1544 {
1545         struct oid_array ref = OID_ARRAY_INIT;
1546         int *status;
1547         int i;
1548
1549         if (args->deepen && alternate_shallow_file) {
1550                 if (*alternate_shallow_file == '\0') { /* --unshallow */
1551                         unlink_or_warn(git_path_shallow(the_repository));
1552                         rollback_lock_file(&shallow_lock);
1553                 } else
1554                         commit_lock_file(&shallow_lock);
1555                 alternate_shallow_file = NULL;
1556                 return;
1557         }
1558
1559         if (!si->shallow || !si->shallow->nr)
1560                 return;
1561
1562         if (args->cloning) {
1563                 /*
1564                  * remote is shallow, but this is a clone, there are
1565                  * no objects in repo to worry about. Accept any
1566                  * shallow points that exist in the pack (iow in repo
1567                  * after get_pack() and reprepare_packed_git())
1568                  */
1569                 struct oid_array extra = OID_ARRAY_INIT;
1570                 struct object_id *oid = si->shallow->oid;
1571                 for (i = 0; i < si->shallow->nr; i++)
1572                         if (has_object_file(&oid[i]))
1573                                 oid_array_append(&extra, &oid[i]);
1574                 if (extra.nr) {
1575                         setup_alternate_shallow(&shallow_lock,
1576                                                 &alternate_shallow_file,
1577                                                 &extra);
1578                         commit_lock_file(&shallow_lock);
1579                         alternate_shallow_file = NULL;
1580                 }
1581                 oid_array_clear(&extra);
1582                 return;
1583         }
1584
1585         if (!si->nr_ours && !si->nr_theirs)
1586                 return;
1587
1588         remove_nonexistent_theirs_shallow(si);
1589         if (!si->nr_ours && !si->nr_theirs)
1590                 return;
1591         for (i = 0; i < nr_sought; i++)
1592                 oid_array_append(&ref, &sought[i]->old_oid);
1593         si->ref = &ref;
1594
1595         if (args->update_shallow) {
1596                 /*
1597                  * remote is also shallow, .git/shallow may be updated
1598                  * so all refs can be accepted. Make sure we only add
1599                  * shallow roots that are actually reachable from new
1600                  * refs.
1601                  */
1602                 struct oid_array extra = OID_ARRAY_INIT;
1603                 struct object_id *oid = si->shallow->oid;
1604                 assign_shallow_commits_to_refs(si, NULL, NULL);
1605                 if (!si->nr_ours && !si->nr_theirs) {
1606                         oid_array_clear(&ref);
1607                         return;
1608                 }
1609                 for (i = 0; i < si->nr_ours; i++)
1610                         oid_array_append(&extra, &oid[si->ours[i]]);
1611                 for (i = 0; i < si->nr_theirs; i++)
1612                         oid_array_append(&extra, &oid[si->theirs[i]]);
1613                 setup_alternate_shallow(&shallow_lock,
1614                                         &alternate_shallow_file,
1615                                         &extra);
1616                 commit_lock_file(&shallow_lock);
1617                 oid_array_clear(&extra);
1618                 oid_array_clear(&ref);
1619                 alternate_shallow_file = NULL;
1620                 return;
1621         }
1622
1623         /*
1624          * remote is also shallow, check what ref is safe to update
1625          * without updating .git/shallow
1626          */
1627         status = xcalloc(nr_sought, sizeof(*status));
1628         assign_shallow_commits_to_refs(si, NULL, status);
1629         if (si->nr_ours || si->nr_theirs) {
1630                 for (i = 0; i < nr_sought; i++)
1631                         if (status[i])
1632                                 sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1633         }
1634         free(status);
1635         oid_array_clear(&ref);
1636 }
1637
1638 static int iterate_ref_map(void *cb_data, struct object_id *oid)
1639 {
1640         struct ref **rm = cb_data;
1641         struct ref *ref = *rm;
1642
1643         if (!ref)
1644                 return -1; /* end of the list */
1645         *rm = ref->next;
1646         oidcpy(oid, &ref->old_oid);
1647         return 0;
1648 }
1649
1650 struct ref *fetch_pack(struct fetch_pack_args *args,
1651                        int fd[],
1652                        const struct ref *ref,
1653                        struct ref **sought, int nr_sought,
1654                        struct oid_array *shallow,
1655                        char **pack_lockfile,
1656                        enum protocol_version version)
1657 {
1658         struct ref *ref_cpy;
1659         struct shallow_info si;
1660         struct oid_array shallows_scratch = OID_ARRAY_INIT;
1661
1662         fetch_pack_setup();
1663         if (nr_sought)
1664                 nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1665
1666         if (args->no_dependents && !args->filter_options.choice) {
1667                 /*
1668                  * The protocol does not support requesting that only the
1669                  * wanted objects be sent, so approximate this by setting a
1670                  * "blob:none" filter if no filter is already set. This works
1671                  * for all object types: note that wanted blobs will still be
1672                  * sent because they are directly specified as a "want".
1673                  *
1674                  * NEEDSWORK: Add an option in the protocol to request that
1675                  * only the wanted objects be sent, and implement it.
1676                  */
1677                 parse_list_objects_filter(&args->filter_options, "blob:none");
1678         }
1679
1680         if (version != protocol_v2 && !ref) {
1681                 packet_flush(fd[1]);
1682                 die(_("no matching remote head"));
1683         }
1684         if (version == protocol_v2) {
1685                 if (shallow->nr)
1686                         BUG("Protocol V2 does not provide shallows at this point in the fetch");
1687                 memset(&si, 0, sizeof(si));
1688                 ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
1689                                            &shallows_scratch, &si,
1690                                            pack_lockfile);
1691         } else {
1692                 prepare_shallow_info(&si, shallow);
1693                 ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1694                                         &si, pack_lockfile);
1695         }
1696         reprepare_packed_git(the_repository);
1697
1698         if (!args->cloning && args->deepen) {
1699                 struct check_connected_options opt = CHECK_CONNECTED_INIT;
1700                 struct ref *iterator = ref_cpy;
1701                 opt.shallow_file = alternate_shallow_file;
1702                 if (args->deepen)
1703                         opt.is_deepening_fetch = 1;
1704                 if (check_connected(iterate_ref_map, &iterator, &opt)) {
1705                         error(_("remote did not send all necessary objects"));
1706                         free_refs(ref_cpy);
1707                         ref_cpy = NULL;
1708                         rollback_lock_file(&shallow_lock);
1709                         goto cleanup;
1710                 }
1711                 args->connectivity_checked = 1;
1712         }
1713
1714         update_shallow(args, sought, nr_sought, &si);
1715 cleanup:
1716         clear_shallow_info(&si);
1717         oid_array_clear(&shallows_scratch);
1718         return ref_cpy;
1719 }
1720
1721 int report_unmatched_refs(struct ref **sought, int nr_sought)
1722 {
1723         int i, ret = 0;
1724
1725         for (i = 0; i < nr_sought; i++) {
1726                 if (!sought[i])
1727                         continue;
1728                 switch (sought[i]->match_status) {
1729                 case REF_MATCHED:
1730                         continue;
1731                 case REF_NOT_MATCHED:
1732                         error(_("no such remote ref %s"), sought[i]->name);
1733                         break;
1734                 case REF_UNADVERTISED_NOT_ALLOWED:
1735                         error(_("Server does not allow request for unadvertised object %s"),
1736                               sought[i]->name);
1737                         break;
1738                 }
1739                 ret = 1;
1740         }
1741         return ret;
1742 }