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

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