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