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