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