Merge branch 'ds/fetch-disable-force-notice'
[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,
139                                  struct packet_reader *reader)
140 {
141         if (args->stateless_rpc && args->deepen) {
142                 /* If we sent a depth we will get back "duplicate"
143                  * shallow and unshallow commands every time there
144                  * is a block of have lines exchanged.
145                  */
146                 while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
147                         if (starts_with(reader->line, "shallow "))
148                                 continue;
149                         if (starts_with(reader->line, "unshallow "))
150                                 continue;
151                         die(_("git fetch-pack: expected shallow list"));
152                 }
153                 if (reader->status != PACKET_READ_FLUSH)
154                         die(_("git fetch-pack: expected a flush packet after shallow list"));
155         }
156 }
157
158 static enum ack_type get_ack(struct packet_reader *reader,
159                              struct object_id *result_oid)
160 {
161         int len;
162         const char *arg;
163
164         if (packet_reader_read(reader) != PACKET_READ_NORMAL)
165                 die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
166         len = reader->pktlen;
167
168         if (!strcmp(reader->line, "NAK"))
169                 return NAK;
170         if (skip_prefix(reader->line, "ACK ", &arg)) {
171                 if (!get_oid_hex(arg, result_oid)) {
172                         arg += 40;
173                         len -= arg - reader->line;
174                         if (len < 1)
175                                 return ACK;
176                         if (strstr(arg, "continue"))
177                                 return ACK_continue;
178                         if (strstr(arg, "common"))
179                                 return ACK_common;
180                         if (strstr(arg, "ready"))
181                                 return ACK_ready;
182                         return ACK;
183                 }
184         }
185         die(_("git fetch-pack: expected ACK/NAK, got '%s'"), reader->line);
186 }
187
188 static void send_request(struct fetch_pack_args *args,
189                          int fd, struct strbuf *buf)
190 {
191         if (args->stateless_rpc) {
192                 send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
193                 packet_flush(fd);
194         } else {
195                 if (write_in_full(fd, buf->buf, buf->len) < 0)
196                         die_errno(_("unable to write to remote"));
197         }
198 }
199
200 static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
201                                         struct object *obj)
202 {
203         rev_list_insert_ref(negotiator, NULL, &obj->oid);
204 }
205
206 #define INITIAL_FLUSH 16
207 #define PIPESAFE_FLUSH 32
208 #define LARGE_FLUSH 16384
209
210 static int next_flush(int stateless_rpc, int count)
211 {
212         if (stateless_rpc) {
213                 if (count < LARGE_FLUSH)
214                         count <<= 1;
215                 else
216                         count = count * 11 / 10;
217         } else {
218                 if (count < PIPESAFE_FLUSH)
219                         count <<= 1;
220                 else
221                         count += PIPESAFE_FLUSH;
222         }
223         return count;
224 }
225
226 static void mark_tips(struct fetch_negotiator *negotiator,
227                       const struct oid_array *negotiation_tips)
228 {
229         int i;
230
231         if (!negotiation_tips) {
232                 for_each_ref(rev_list_insert_ref_oid, negotiator);
233                 return;
234         }
235
236         for (i = 0; i < negotiation_tips->nr; i++)
237                 rev_list_insert_ref(negotiator, NULL,
238                                     &negotiation_tips->oid[i]);
239         return;
240 }
241
242 static int find_common(struct fetch_negotiator *negotiator,
243                        struct fetch_pack_args *args,
244                        int fd[2], struct object_id *result_oid,
245                        struct ref *refs)
246 {
247         int fetching;
248         int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
249         const struct object_id *oid;
250         unsigned in_vain = 0;
251         int got_continue = 0;
252         int got_ready = 0;
253         struct strbuf req_buf = STRBUF_INIT;
254         size_t state_len = 0;
255         struct packet_reader reader;
256
257         if (args->stateless_rpc && multi_ack == 1)
258                 die(_("--stateless-rpc requires multi_ack_detailed"));
259
260         packet_reader_init(&reader, fd[0], NULL, 0,
261                            PACKET_READ_CHOMP_NEWLINE |
262                            PACKET_READ_DIE_ON_ERR_PACKET);
263
264         if (!args->no_dependents) {
265                 mark_tips(negotiator, args->negotiation_tips);
266                 for_each_cached_alternate(negotiator, insert_one_alternate_object);
267         }
268
269         fetching = 0;
270         for ( ; refs ; refs = refs->next) {
271                 struct object_id *remote = &refs->old_oid;
272                 const char *remote_hex;
273                 struct object *o;
274
275                 /*
276                  * If that object is complete (i.e. it is an ancestor of a
277                  * local ref), we tell them we have it but do not have to
278                  * tell them about its ancestors, which they already know
279                  * about.
280                  *
281                  * We use lookup_object here because we are only
282                  * interested in the case we *know* the object is
283                  * reachable and we have already scanned it.
284                  *
285                  * Do this only if args->no_dependents is false (if it is true,
286                  * we cannot trust the object flags).
287                  */
288                 if (!args->no_dependents &&
289                     ((o = lookup_object(the_repository, remote)) != NULL) &&
290                                 (o->flags & COMPLETE)) {
291                         continue;
292                 }
293
294                 remote_hex = oid_to_hex(remote);
295                 if (!fetching) {
296                         struct strbuf c = STRBUF_INIT;
297                         if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
298                         if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
299                         if (no_done)            strbuf_addstr(&c, " no-done");
300                         if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
301                         if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
302                         if (args->deepen_relative) strbuf_addstr(&c, " deepen-relative");
303                         if (args->use_thin_pack) strbuf_addstr(&c, " thin-pack");
304                         if (args->no_progress)   strbuf_addstr(&c, " no-progress");
305                         if (args->include_tag)   strbuf_addstr(&c, " include-tag");
306                         if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
307                         if (deepen_since_ok)    strbuf_addstr(&c, " deepen-since");
308                         if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
309                         if (agent_supported)    strbuf_addf(&c, " agent=%s",
310                                                             git_user_agent_sanitized());
311                         if (args->filter_options.choice)
312                                 strbuf_addstr(&c, " filter");
313                         packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
314                         strbuf_release(&c);
315                 } else
316                         packet_buf_write(&req_buf, "want %s\n", remote_hex);
317                 fetching++;
318         }
319
320         if (!fetching) {
321                 strbuf_release(&req_buf);
322                 packet_flush(fd[1]);
323                 return 1;
324         }
325
326         if (is_repository_shallow(the_repository))
327                 write_shallow_commits(&req_buf, 1, NULL);
328         if (args->depth > 0)
329                 packet_buf_write(&req_buf, "deepen %d", args->depth);
330         if (args->deepen_since) {
331                 timestamp_t max_age = approxidate(args->deepen_since);
332                 packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
333         }
334         if (args->deepen_not) {
335                 int i;
336                 for (i = 0; i < args->deepen_not->nr; i++) {
337                         struct string_list_item *s = args->deepen_not->items + i;
338                         packet_buf_write(&req_buf, "deepen-not %s", s->string);
339                 }
340         }
341         if (server_supports_filtering && args->filter_options.choice) {
342                 struct strbuf expanded_filter_spec = STRBUF_INIT;
343                 expand_list_objects_filter_spec(&args->filter_options,
344                                                 &expanded_filter_spec);
345                 packet_buf_write(&req_buf, "filter %s",
346                                  expanded_filter_spec.buf);
347                 strbuf_release(&expanded_filter_spec);
348         }
349         packet_buf_flush(&req_buf);
350         state_len = req_buf.len;
351
352         if (args->deepen) {
353                 const char *arg;
354                 struct object_id oid;
355
356                 send_request(args, fd[1], &req_buf);
357                 while (packet_reader_read(&reader) == PACKET_READ_NORMAL) {
358                         if (skip_prefix(reader.line, "shallow ", &arg)) {
359                                 if (get_oid_hex(arg, &oid))
360                                         die(_("invalid shallow line: %s"), reader.line);
361                                 register_shallow(the_repository, &oid);
362                                 continue;
363                         }
364                         if (skip_prefix(reader.line, "unshallow ", &arg)) {
365                                 if (get_oid_hex(arg, &oid))
366                                         die(_("invalid unshallow line: %s"), reader.line);
367                                 if (!lookup_object(the_repository, &oid))
368                                         die(_("object not found: %s"), reader.line);
369                                 /* make sure that it is parsed as shallow */
370                                 if (!parse_object(the_repository, &oid))
371                                         die(_("error in object: %s"), reader.line);
372                                 if (unregister_shallow(&oid))
373                                         die(_("no shallow found: %s"), reader.line);
374                                 continue;
375                         }
376                         die(_("expected shallow/unshallow, got %s"), reader.line);
377                 }
378         } else if (!args->stateless_rpc)
379                 send_request(args, fd[1], &req_buf);
380
381         if (!args->stateless_rpc) {
382                 /* If we aren't using the stateless-rpc interface
383                  * we don't need to retain the headers.
384                  */
385                 strbuf_setlen(&req_buf, 0);
386                 state_len = 0;
387         }
388
389         flushes = 0;
390         retval = -1;
391         if (args->no_dependents)
392                 goto done;
393         while ((oid = negotiator->next(negotiator))) {
394                 packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
395                 print_verbose(args, "have %s", oid_to_hex(oid));
396                 in_vain++;
397                 if (flush_at <= ++count) {
398                         int ack;
399
400                         packet_buf_flush(&req_buf);
401                         send_request(args, fd[1], &req_buf);
402                         strbuf_setlen(&req_buf, state_len);
403                         flushes++;
404                         flush_at = next_flush(args->stateless_rpc, count);
405
406                         /*
407                          * We keep one window "ahead" of the other side, and
408                          * will wait for an ACK only on the next one
409                          */
410                         if (!args->stateless_rpc && count == INITIAL_FLUSH)
411                                 continue;
412
413                         consume_shallow_list(args, &reader);
414                         do {
415                                 ack = get_ack(&reader, result_oid);
416                                 if (ack)
417                                         print_verbose(args, _("got %s %d %s"), "ack",
418                                                       ack, oid_to_hex(result_oid));
419                                 switch (ack) {
420                                 case ACK:
421                                         flushes = 0;
422                                         multi_ack = 0;
423                                         retval = 0;
424                                         goto done;
425                                 case ACK_common:
426                                 case ACK_ready:
427                                 case ACK_continue: {
428                                         struct commit *commit =
429                                                 lookup_commit(the_repository,
430                                                               result_oid);
431                                         int was_common;
432
433                                         if (!commit)
434                                                 die(_("invalid commit %s"), oid_to_hex(result_oid));
435                                         was_common = negotiator->ack(negotiator, commit);
436                                         if (args->stateless_rpc
437                                          && ack == ACK_common
438                                          && !was_common) {
439                                                 /* We need to replay the have for this object
440                                                  * on the next RPC request so the peer knows
441                                                  * it is in common with us.
442                                                  */
443                                                 const char *hex = oid_to_hex(result_oid);
444                                                 packet_buf_write(&req_buf, "have %s\n", hex);
445                                                 state_len = req_buf.len;
446                                                 /*
447                                                  * Reset in_vain because an ack
448                                                  * for this commit has not been
449                                                  * seen.
450                                                  */
451                                                 in_vain = 0;
452                                         } else if (!args->stateless_rpc
453                                                    || ack != ACK_common)
454                                                 in_vain = 0;
455                                         retval = 0;
456                                         got_continue = 1;
457                                         if (ack == ACK_ready)
458                                                 got_ready = 1;
459                                         break;
460                                         }
461                                 }
462                         } while (ack);
463                         flushes--;
464                         if (got_continue && MAX_IN_VAIN < in_vain) {
465                                 print_verbose(args, _("giving up"));
466                                 break; /* give up */
467                         }
468                         if (got_ready)
469                                 break;
470                 }
471         }
472 done:
473         if (!got_ready || !no_done) {
474                 packet_buf_write(&req_buf, "done\n");
475                 send_request(args, fd[1], &req_buf);
476         }
477         print_verbose(args, _("done"));
478         if (retval != 0) {
479                 multi_ack = 0;
480                 flushes++;
481         }
482         strbuf_release(&req_buf);
483
484         if (!got_ready || !no_done)
485                 consume_shallow_list(args, &reader);
486         while (flushes || multi_ack) {
487                 int ack = get_ack(&reader, result_oid);
488                 if (ack) {
489                         print_verbose(args, _("got %s (%d) %s"), "ack",
490                                       ack, oid_to_hex(result_oid));
491                         if (ack == ACK)
492                                 return 0;
493                         multi_ack = 1;
494                         continue;
495                 }
496                 flushes--;
497         }
498         /* it is no error to fetch into a completely empty repo */
499         return count ? retval : 0;
500 }
501
502 static struct commit_list *complete;
503
504 static int mark_complete(const struct object_id *oid)
505 {
506         struct object *o = parse_object(the_repository, oid);
507
508         while (o && o->type == OBJ_TAG) {
509                 struct tag *t = (struct tag *) o;
510                 if (!t->tagged)
511                         break; /* broken repository */
512                 o->flags |= COMPLETE;
513                 o = parse_object(the_repository, &t->tagged->oid);
514         }
515         if (o && o->type == OBJ_COMMIT) {
516                 struct commit *commit = (struct commit *)o;
517                 if (!(commit->object.flags & COMPLETE)) {
518                         commit->object.flags |= COMPLETE;
519                         commit_list_insert(commit, &complete);
520                 }
521         }
522         return 0;
523 }
524
525 static int mark_complete_oid(const char *refname, const struct object_id *oid,
526                              int flag, void *cb_data)
527 {
528         return mark_complete(oid);
529 }
530
531 static void mark_recent_complete_commits(struct fetch_pack_args *args,
532                                          timestamp_t cutoff)
533 {
534         while (complete && cutoff <= complete->item->date) {
535                 print_verbose(args, _("Marking %s as complete"),
536                               oid_to_hex(&complete->item->object.oid));
537                 pop_most_recent_commit(&complete, COMPLETE);
538         }
539 }
540
541 static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
542 {
543         for (; refs; refs = refs->next)
544                 oidset_insert(oids, &refs->old_oid);
545 }
546
547 static int is_unmatched_ref(const struct ref *ref)
548 {
549         struct object_id oid;
550         const char *p;
551         return  ref->match_status == REF_NOT_MATCHED &&
552                 !parse_oid_hex(ref->name, &oid, &p) &&
553                 *p == '\0' &&
554                 oideq(&oid, &ref->old_oid);
555 }
556
557 static void filter_refs(struct fetch_pack_args *args,
558                         struct ref **refs,
559                         struct ref **sought, int nr_sought)
560 {
561         struct ref *newlist = NULL;
562         struct ref **newtail = &newlist;
563         struct ref *unmatched = NULL;
564         struct ref *ref, *next;
565         struct oidset tip_oids = OIDSET_INIT;
566         int i;
567         int strict = !(allow_unadvertised_object_request &
568                        (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1));
569
570         i = 0;
571         for (ref = *refs; ref; ref = next) {
572                 int keep = 0;
573                 next = ref->next;
574
575                 if (starts_with(ref->name, "refs/") &&
576                     check_refname_format(ref->name, 0)) {
577                         /*
578                          * trash or a peeled value; do not even add it to
579                          * unmatched list
580                          */
581                         free_one_ref(ref);
582                         continue;
583                 } else {
584                         while (i < nr_sought) {
585                                 int cmp = strcmp(ref->name, sought[i]->name);
586                                 if (cmp < 0)
587                                         break; /* definitely do not have it */
588                                 else if (cmp == 0) {
589                                         keep = 1; /* definitely have it */
590                                         sought[i]->match_status = REF_MATCHED;
591                                 }
592                                 i++;
593                         }
594
595                         if (!keep && args->fetch_all &&
596                             (!args->deepen || !starts_with(ref->name, "refs/tags/")))
597                                 keep = 1;
598                 }
599
600                 if (keep) {
601                         *newtail = ref;
602                         ref->next = NULL;
603                         newtail = &ref->next;
604                 } else {
605                         ref->next = unmatched;
606                         unmatched = ref;
607                 }
608         }
609
610         if (strict) {
611                 for (i = 0; i < nr_sought; i++) {
612                         ref = sought[i];
613                         if (!is_unmatched_ref(ref))
614                                 continue;
615
616                         add_refs_to_oidset(&tip_oids, unmatched);
617                         add_refs_to_oidset(&tip_oids, newlist);
618                         break;
619                 }
620         }
621
622         /* Append unmatched requests to the list */
623         for (i = 0; i < nr_sought; i++) {
624                 ref = sought[i];
625                 if (!is_unmatched_ref(ref))
626                         continue;
627
628                 if (!strict || oidset_contains(&tip_oids, &ref->old_oid)) {
629                         ref->match_status = REF_MATCHED;
630                         *newtail = copy_ref(ref);
631                         newtail = &(*newtail)->next;
632                 } else {
633                         ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
634                 }
635         }
636
637         oidset_clear(&tip_oids);
638         free_refs(unmatched);
639
640         *refs = newlist;
641 }
642
643 static void mark_alternate_complete(struct fetch_negotiator *unused,
644                                     struct object *obj)
645 {
646         mark_complete(&obj->oid);
647 }
648
649 struct loose_object_iter {
650         struct oidset *loose_object_set;
651         struct ref *refs;
652 };
653
654 /*
655  * Mark recent commits available locally and reachable from a local ref as
656  * COMPLETE. If args->no_dependents is false, also mark COMPLETE remote refs as
657  * COMMON_REF (otherwise, we are not planning to participate in negotiation, and
658  * thus do not need COMMON_REF marks).
659  *
660  * The cutoff time for recency is determined by this heuristic: it is the
661  * earliest commit time of the objects in refs that are commits and that we know
662  * the commit time of.
663  */
664 static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
665                                          struct fetch_pack_args *args,
666                                          struct ref **refs)
667 {
668         struct ref *ref;
669         int old_save_commit_buffer = save_commit_buffer;
670         timestamp_t cutoff = 0;
671
672         save_commit_buffer = 0;
673
674         for (ref = *refs; ref; ref = ref->next) {
675                 struct object *o;
676
677                 if (!has_object_file_with_flags(&ref->old_oid,
678                                                 OBJECT_INFO_QUICK))
679                         continue;
680                 o = parse_object(the_repository, &ref->old_oid);
681                 if (!o)
682                         continue;
683
684                 /* We already have it -- which may mean that we were
685                  * in sync with the other side at some time after
686                  * that (it is OK if we guess wrong here).
687                  */
688                 if (o->type == OBJ_COMMIT) {
689                         struct commit *commit = (struct commit *)o;
690                         if (!cutoff || cutoff < commit->date)
691                                 cutoff = commit->date;
692                 }
693         }
694
695         if (!args->deepen) {
696                 for_each_ref(mark_complete_oid, NULL);
697                 for_each_cached_alternate(NULL, mark_alternate_complete);
698                 commit_list_sort_by_date(&complete);
699                 if (cutoff)
700                         mark_recent_complete_commits(args, cutoff);
701         }
702
703         /*
704          * Mark all complete remote refs as common refs.
705          * Don't mark them common yet; the server has to be told so first.
706          */
707         for (ref = *refs; ref; ref = ref->next) {
708                 struct object *o = deref_tag(the_repository,
709                                              lookup_object(the_repository,
710                                              &ref->old_oid),
711                                              NULL, 0);
712
713                 if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
714                         continue;
715
716                 negotiator->known_common(negotiator,
717                                          (struct commit *)o);
718         }
719
720         save_commit_buffer = old_save_commit_buffer;
721 }
722
723 /*
724  * Returns 1 if every object pointed to by the given remote refs is available
725  * locally and reachable from a local ref, and 0 otherwise.
726  */
727 static int everything_local(struct fetch_pack_args *args,
728                             struct ref **refs)
729 {
730         struct ref *ref;
731         int retval;
732
733         for (retval = 1, ref = *refs; ref ; ref = ref->next) {
734                 const struct object_id *remote = &ref->old_oid;
735                 struct object *o;
736
737                 o = lookup_object(the_repository, remote);
738                 if (!o || !(o->flags & COMPLETE)) {
739                         retval = 0;
740                         print_verbose(args, "want %s (%s)", oid_to_hex(remote),
741                                       ref->name);
742                         continue;
743                 }
744                 print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
745                               ref->name);
746         }
747
748         return retval;
749 }
750
751 static int sideband_demux(int in, int out, void *data)
752 {
753         int *xd = data;
754         int ret;
755
756         ret = recv_sideband("fetch-pack", xd[0], out);
757         close(out);
758         return ret;
759 }
760
761 static int get_pack(struct fetch_pack_args *args,
762                     int xd[2], char **pack_lockfile)
763 {
764         struct async demux;
765         int do_keep = args->keep_pack;
766         const char *cmd_name;
767         struct pack_header header;
768         int pass_header = 0;
769         struct child_process cmd = CHILD_PROCESS_INIT;
770         int ret;
771
772         memset(&demux, 0, sizeof(demux));
773         if (use_sideband) {
774                 /* xd[] is talking with upload-pack; subprocess reads from
775                  * xd[0], spits out band#2 to stderr, and feeds us band#1
776                  * through demux->out.
777                  */
778                 demux.proc = sideband_demux;
779                 demux.data = xd;
780                 demux.out = -1;
781                 demux.isolate_sigpipe = 1;
782                 if (start_async(&demux))
783                         die(_("fetch-pack: unable to fork off sideband demultiplexer"));
784         }
785         else
786                 demux.out = xd[0];
787
788         if (!args->keep_pack && unpack_limit) {
789
790                 if (read_pack_header(demux.out, &header))
791                         die(_("protocol error: bad pack header"));
792                 pass_header = 1;
793                 if (ntohl(header.hdr_entries) < unpack_limit)
794                         do_keep = 0;
795                 else
796                         do_keep = 1;
797         }
798
799         if (alternate_shallow_file) {
800                 argv_array_push(&cmd.args, "--shallow-file");
801                 argv_array_push(&cmd.args, alternate_shallow_file);
802         }
803
804         if (do_keep || args->from_promisor) {
805                 if (pack_lockfile)
806                         cmd.out = -1;
807                 cmd_name = "index-pack";
808                 argv_array_push(&cmd.args, cmd_name);
809                 argv_array_push(&cmd.args, "--stdin");
810                 if (!args->quiet && !args->no_progress)
811                         argv_array_push(&cmd.args, "-v");
812                 if (args->use_thin_pack)
813                         argv_array_push(&cmd.args, "--fix-thin");
814                 if (do_keep && (args->lock_pack || unpack_limit)) {
815                         char hostname[HOST_NAME_MAX + 1];
816                         if (xgethostname(hostname, sizeof(hostname)))
817                                 xsnprintf(hostname, sizeof(hostname), "localhost");
818                         argv_array_pushf(&cmd.args,
819                                         "--keep=fetch-pack %"PRIuMAX " on %s",
820                                         (uintmax_t)getpid(), hostname);
821                 }
822                 if (args->check_self_contained_and_connected)
823                         argv_array_push(&cmd.args, "--check-self-contained-and-connected");
824                 if (args->from_promisor)
825                         argv_array_push(&cmd.args, "--promisor");
826         }
827         else {
828                 cmd_name = "unpack-objects";
829                 argv_array_push(&cmd.args, cmd_name);
830                 if (args->quiet || args->no_progress)
831                         argv_array_push(&cmd.args, "-q");
832                 args->check_self_contained_and_connected = 0;
833         }
834
835         if (pass_header)
836                 argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
837                                  ntohl(header.hdr_version),
838                                  ntohl(header.hdr_entries));
839         if (fetch_fsck_objects >= 0
840             ? fetch_fsck_objects
841             : transfer_fsck_objects >= 0
842             ? transfer_fsck_objects
843             : 0) {
844                 if (args->from_promisor)
845                         /*
846                          * We cannot use --strict in index-pack because it
847                          * checks both broken objects and links, but we only
848                          * want to check for broken objects.
849                          */
850                         argv_array_push(&cmd.args, "--fsck-objects");
851                 else
852                         argv_array_pushf(&cmd.args, "--strict%s",
853                                          fsck_msg_types.buf);
854         }
855
856         cmd.in = demux.out;
857         cmd.git_cmd = 1;
858         if (start_command(&cmd))
859                 die(_("fetch-pack: unable to fork off %s"), cmd_name);
860         if (do_keep && pack_lockfile) {
861                 *pack_lockfile = index_pack_lockfile(cmd.out);
862                 close(cmd.out);
863         }
864
865         if (!use_sideband)
866                 /* Closed by start_command() */
867                 xd[0] = -1;
868
869         ret = finish_command(&cmd);
870         if (!ret || (args->check_self_contained_and_connected && ret == 1))
871                 args->self_contained_and_connected =
872                         args->check_self_contained_and_connected &&
873                         ret == 0;
874         else
875                 die(_("%s failed"), cmd_name);
876         if (use_sideband && finish_async(&demux))
877                 die(_("error in sideband demultiplexer"));
878         return 0;
879 }
880
881 static int cmp_ref_by_name(const void *a_, const void *b_)
882 {
883         const struct ref *a = *((const struct ref **)a_);
884         const struct ref *b = *((const struct ref **)b_);
885         return strcmp(a->name, b->name);
886 }
887
888 static struct ref *do_fetch_pack(struct fetch_pack_args *args,
889                                  int fd[2],
890                                  const struct ref *orig_ref,
891                                  struct ref **sought, int nr_sought,
892                                  struct shallow_info *si,
893                                  char **pack_lockfile)
894 {
895         struct ref *ref = copy_ref_list(orig_ref);
896         struct object_id oid;
897         const char *agent_feature;
898         int agent_len;
899         struct fetch_negotiator negotiator;
900         fetch_negotiator_init(&negotiator, negotiation_algorithm);
901
902         sort_ref_list(&ref, ref_compare_name);
903         QSORT(sought, nr_sought, cmp_ref_by_name);
904
905         if ((agent_feature = server_feature_value("agent", &agent_len))) {
906                 agent_supported = 1;
907                 if (agent_len)
908                         print_verbose(args, _("Server version is %.*s"),
909                                       agent_len, agent_feature);
910         }
911
912         if (server_supports("shallow"))
913                 print_verbose(args, _("Server supports %s"), "shallow");
914         else if (args->depth > 0 || is_repository_shallow(the_repository))
915                 die(_("Server does not support shallow clients"));
916         if (args->depth > 0 || args->deepen_since || args->deepen_not)
917                 args->deepen = 1;
918         if (server_supports("multi_ack_detailed")) {
919                 print_verbose(args, _("Server supports %s"), "multi_ack_detailed");
920                 multi_ack = 2;
921                 if (server_supports("no-done")) {
922                         print_verbose(args, _("Server supports %s"), "no-done");
923                         if (args->stateless_rpc)
924                                 no_done = 1;
925                 }
926         }
927         else if (server_supports("multi_ack")) {
928                 print_verbose(args, _("Server supports %s"), "multi_ack");
929                 multi_ack = 1;
930         }
931         if (server_supports("side-band-64k")) {
932                 print_verbose(args, _("Server supports %s"), "side-band-64k");
933                 use_sideband = 2;
934         }
935         else if (server_supports("side-band")) {
936                 print_verbose(args, _("Server supports %s"), "side-band");
937                 use_sideband = 1;
938         }
939         if (server_supports("allow-tip-sha1-in-want")) {
940                 print_verbose(args, _("Server supports %s"), "allow-tip-sha1-in-want");
941                 allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
942         }
943         if (server_supports("allow-reachable-sha1-in-want")) {
944                 print_verbose(args, _("Server supports %s"), "allow-reachable-sha1-in-want");
945                 allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
946         }
947         if (server_supports("thin-pack"))
948                 print_verbose(args, _("Server supports %s"), "thin-pack");
949         else
950                 args->use_thin_pack = 0;
951         if (server_supports("no-progress"))
952                 print_verbose(args, _("Server supports %s"), "no-progress");
953         else
954                 args->no_progress = 0;
955         if (server_supports("include-tag"))
956                 print_verbose(args, _("Server supports %s"), "include-tag");
957         else
958                 args->include_tag = 0;
959         if (server_supports("ofs-delta"))
960                 print_verbose(args, _("Server supports %s"), "ofs-delta");
961         else
962                 prefer_ofs_delta = 0;
963
964         if (server_supports("filter")) {
965                 server_supports_filtering = 1;
966                 print_verbose(args, _("Server supports %s"), "filter");
967         } else if (args->filter_options.choice) {
968                 warning("filtering not recognized by server, ignoring");
969         }
970
971         if (server_supports("deepen-since")) {
972                 print_verbose(args, _("Server supports %s"), "deepen-since");
973                 deepen_since_ok = 1;
974         } else if (args->deepen_since)
975                 die(_("Server does not support --shallow-since"));
976         if (server_supports("deepen-not")) {
977                 print_verbose(args, _("Server supports %s"), "deepen-not");
978                 deepen_not_ok = 1;
979         } else if (args->deepen_not)
980                 die(_("Server does not support --shallow-exclude"));
981         if (server_supports("deepen-relative"))
982                 print_verbose(args, _("Server supports %s"), "deepen-relative");
983         else if (args->deepen_relative)
984                 die(_("Server does not support --deepen"));
985
986         if (!args->no_dependents) {
987                 mark_complete_and_common_ref(&negotiator, args, &ref);
988                 filter_refs(args, &ref, sought, nr_sought);
989                 if (everything_local(args, &ref)) {
990                         packet_flush(fd[1]);
991                         goto all_done;
992                 }
993         } else {
994                 filter_refs(args, &ref, sought, nr_sought);
995         }
996         if (find_common(&negotiator, args, fd, &oid, ref) < 0)
997                 if (!args->keep_pack)
998                         /* When cloning, it is not unusual to have
999                          * no common commit.
1000                          */
1001                         warning(_("no common commits"));
1002
1003         if (args->stateless_rpc)
1004                 packet_flush(fd[1]);
1005         if (args->deepen)
1006                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
1007                                         NULL);
1008         else if (si->nr_ours || si->nr_theirs)
1009                 alternate_shallow_file = setup_temporary_shallow(si->shallow);
1010         else
1011                 alternate_shallow_file = NULL;
1012         if (get_pack(args, fd, pack_lockfile))
1013                 die(_("git fetch-pack: fetch failed."));
1014
1015  all_done:
1016         negotiator.release(&negotiator);
1017         return ref;
1018 }
1019
1020 static void add_shallow_requests(struct strbuf *req_buf,
1021                                  const struct fetch_pack_args *args)
1022 {
1023         if (is_repository_shallow(the_repository))
1024                 write_shallow_commits(req_buf, 1, NULL);
1025         if (args->depth > 0)
1026                 packet_buf_write(req_buf, "deepen %d", args->depth);
1027         if (args->deepen_since) {
1028                 timestamp_t max_age = approxidate(args->deepen_since);
1029                 packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
1030         }
1031         if (args->deepen_not) {
1032                 int i;
1033                 for (i = 0; i < args->deepen_not->nr; i++) {
1034                         struct string_list_item *s = args->deepen_not->items + i;
1035                         packet_buf_write(req_buf, "deepen-not %s", s->string);
1036                 }
1037         }
1038         if (args->deepen_relative)
1039                 packet_buf_write(req_buf, "deepen-relative\n");
1040 }
1041
1042 static void add_wants(int no_dependents, const struct ref *wants, struct strbuf *req_buf)
1043 {
1044         int use_ref_in_want = server_supports_feature("fetch", "ref-in-want", 0);
1045
1046         for ( ; wants ; wants = wants->next) {
1047                 const struct object_id *remote = &wants->old_oid;
1048                 struct object *o;
1049
1050                 /*
1051                  * If that object is complete (i.e. it is an ancestor of a
1052                  * local ref), we tell them we have it but do not have to
1053                  * tell them about its ancestors, which they already know
1054                  * about.
1055                  *
1056                  * We use lookup_object here because we are only
1057                  * interested in the case we *know* the object is
1058                  * reachable and we have already scanned it.
1059                  *
1060                  * Do this only if args->no_dependents is false (if it is true,
1061                  * we cannot trust the object flags).
1062                  */
1063                 if (!no_dependents &&
1064                     ((o = lookup_object(the_repository, remote)) != NULL) &&
1065                     (o->flags & COMPLETE)) {
1066                         continue;
1067                 }
1068
1069                 if (!use_ref_in_want || wants->exact_oid)
1070                         packet_buf_write(req_buf, "want %s\n", oid_to_hex(remote));
1071                 else
1072                         packet_buf_write(req_buf, "want-ref %s\n", wants->name);
1073         }
1074 }
1075
1076 static void add_common(struct strbuf *req_buf, struct oidset *common)
1077 {
1078         struct oidset_iter iter;
1079         const struct object_id *oid;
1080         oidset_iter_init(common, &iter);
1081
1082         while ((oid = oidset_iter_next(&iter))) {
1083                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1084         }
1085 }
1086
1087 static int add_haves(struct fetch_negotiator *negotiator,
1088                      struct strbuf *req_buf,
1089                      int *haves_to_send, int *in_vain)
1090 {
1091         int ret = 0;
1092         int haves_added = 0;
1093         const struct object_id *oid;
1094
1095         while ((oid = negotiator->next(negotiator))) {
1096                 packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
1097                 if (++haves_added >= *haves_to_send)
1098                         break;
1099         }
1100
1101         *in_vain += haves_added;
1102         if (!haves_added || *in_vain >= MAX_IN_VAIN) {
1103                 /* Send Done */
1104                 packet_buf_write(req_buf, "done\n");
1105                 ret = 1;
1106         }
1107
1108         /* Increase haves to send on next round */
1109         *haves_to_send = next_flush(1, *haves_to_send);
1110
1111         return ret;
1112 }
1113
1114 static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
1115                               const struct fetch_pack_args *args,
1116                               const struct ref *wants, struct oidset *common,
1117                               int *haves_to_send, int *in_vain,
1118                               int sideband_all)
1119 {
1120         int ret = 0;
1121         struct strbuf req_buf = STRBUF_INIT;
1122
1123         if (server_supports_v2("fetch", 1))
1124                 packet_buf_write(&req_buf, "command=fetch");
1125         if (server_supports_v2("agent", 0))
1126                 packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
1127         if (args->server_options && args->server_options->nr &&
1128             server_supports_v2("server-option", 1)) {
1129                 int i;
1130                 for (i = 0; i < args->server_options->nr; i++)
1131                         packet_buf_write(&req_buf, "server-option=%s",
1132                                          args->server_options->items[i].string);
1133         }
1134
1135         packet_buf_delim(&req_buf);
1136         if (args->use_thin_pack)
1137                 packet_buf_write(&req_buf, "thin-pack");
1138         if (args->no_progress)
1139                 packet_buf_write(&req_buf, "no-progress");
1140         if (args->include_tag)
1141                 packet_buf_write(&req_buf, "include-tag");
1142         if (prefer_ofs_delta)
1143                 packet_buf_write(&req_buf, "ofs-delta");
1144         if (sideband_all)
1145                 packet_buf_write(&req_buf, "sideband-all");
1146
1147         /* Add shallow-info and deepen request */
1148         if (server_supports_feature("fetch", "shallow", 0))
1149                 add_shallow_requests(&req_buf, args);
1150         else if (is_repository_shallow(the_repository) || args->deepen)
1151                 die(_("Server does not support shallow requests"));
1152
1153         /* Add filter */
1154         if (server_supports_feature("fetch", "filter", 0) &&
1155             args->filter_options.choice) {
1156                 struct strbuf expanded_filter_spec = STRBUF_INIT;
1157                 print_verbose(args, _("Server supports filter"));
1158                 expand_list_objects_filter_spec(&args->filter_options,
1159                                                 &expanded_filter_spec);
1160                 packet_buf_write(&req_buf, "filter %s",
1161                                  expanded_filter_spec.buf);
1162                 strbuf_release(&expanded_filter_spec);
1163         } else if (args->filter_options.choice) {
1164                 warning("filtering not recognized by server, ignoring");
1165         }
1166
1167         /* add wants */
1168         add_wants(args->no_dependents, wants, &req_buf);
1169
1170         if (args->no_dependents) {
1171                 packet_buf_write(&req_buf, "done");
1172                 ret = 1;
1173         } else {
1174                 /* Add all of the common commits we've found in previous rounds */
1175                 add_common(&req_buf, common);
1176
1177                 /* Add initial haves */
1178                 ret = add_haves(negotiator, &req_buf, haves_to_send, in_vain);
1179         }
1180
1181         /* Send request */
1182         packet_buf_flush(&req_buf);
1183         if (write_in_full(fd_out, req_buf.buf, req_buf.len) < 0)
1184                 die_errno(_("unable to write request to remote"));
1185
1186         strbuf_release(&req_buf);
1187         return ret;
1188 }
1189
1190 /*
1191  * Processes a section header in a server's response and checks if it matches
1192  * `section`.  If the value of `peek` is 1, the header line will be peeked (and
1193  * not consumed); if 0, the line will be consumed and the function will die if
1194  * the section header doesn't match what was expected.
1195  */
1196 static int process_section_header(struct packet_reader *reader,
1197                                   const char *section, int peek)
1198 {
1199         int ret;
1200
1201         if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
1202                 die(_("error reading section header '%s'"), section);
1203
1204         ret = !strcmp(reader->line, section);
1205
1206         if (!peek) {
1207                 if (!ret)
1208                         die(_("expected '%s', received '%s'"),
1209                             section, reader->line);
1210                 packet_reader_read(reader);
1211         }
1212
1213         return ret;
1214 }
1215
1216 static int process_acks(struct fetch_negotiator *negotiator,
1217                         struct packet_reader *reader,
1218                         struct oidset *common)
1219 {
1220         /* received */
1221         int received_ready = 0;
1222         int received_ack = 0;
1223
1224         process_section_header(reader, "acknowledgments", 0);
1225         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1226                 const char *arg;
1227
1228                 if (!strcmp(reader->line, "NAK"))
1229                         continue;
1230
1231                 if (skip_prefix(reader->line, "ACK ", &arg)) {
1232                         struct object_id oid;
1233                         if (!get_oid_hex(arg, &oid)) {
1234                                 struct commit *commit;
1235                                 oidset_insert(common, &oid);
1236                                 commit = lookup_commit(the_repository, &oid);
1237                                 negotiator->ack(negotiator, commit);
1238                         }
1239                         continue;
1240                 }
1241
1242                 if (!strcmp(reader->line, "ready")) {
1243                         received_ready = 1;
1244                         continue;
1245                 }
1246
1247                 die(_("unexpected acknowledgment line: '%s'"), reader->line);
1248         }
1249
1250         if (reader->status != PACKET_READ_FLUSH &&
1251             reader->status != PACKET_READ_DELIM)
1252                 die(_("error processing acks: %d"), reader->status);
1253
1254         /*
1255          * If an "acknowledgments" section is sent, a packfile is sent if and
1256          * only if "ready" was sent in this section. The other sections
1257          * ("shallow-info" and "wanted-refs") are sent only if a packfile is
1258          * sent. Therefore, a DELIM is expected if "ready" is sent, and a FLUSH
1259          * otherwise.
1260          */
1261         if (received_ready && reader->status != PACKET_READ_DELIM)
1262                 die(_("expected packfile to be sent after 'ready'"));
1263         if (!received_ready && reader->status != PACKET_READ_FLUSH)
1264                 die(_("expected no other sections to be sent after no 'ready'"));
1265
1266         /* return 0 if no common, 1 if there are common, or 2 if ready */
1267         return received_ready ? 2 : (received_ack ? 1 : 0);
1268 }
1269
1270 static void receive_shallow_info(struct fetch_pack_args *args,
1271                                  struct packet_reader *reader,
1272                                  struct oid_array *shallows,
1273                                  struct shallow_info *si)
1274 {
1275         int unshallow_received = 0;
1276
1277         process_section_header(reader, "shallow-info", 0);
1278         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1279                 const char *arg;
1280                 struct object_id oid;
1281
1282                 if (skip_prefix(reader->line, "shallow ", &arg)) {
1283                         if (get_oid_hex(arg, &oid))
1284                                 die(_("invalid shallow line: %s"), reader->line);
1285                         oid_array_append(shallows, &oid);
1286                         continue;
1287                 }
1288                 if (skip_prefix(reader->line, "unshallow ", &arg)) {
1289                         if (get_oid_hex(arg, &oid))
1290                                 die(_("invalid unshallow line: %s"), reader->line);
1291                         if (!lookup_object(the_repository, &oid))
1292                                 die(_("object not found: %s"), reader->line);
1293                         /* make sure that it is parsed as shallow */
1294                         if (!parse_object(the_repository, &oid))
1295                                 die(_("error in object: %s"), reader->line);
1296                         if (unregister_shallow(&oid))
1297                                 die(_("no shallow found: %s"), reader->line);
1298                         unshallow_received = 1;
1299                         continue;
1300                 }
1301                 die(_("expected shallow/unshallow, got %s"), reader->line);
1302         }
1303
1304         if (reader->status != PACKET_READ_FLUSH &&
1305             reader->status != PACKET_READ_DELIM)
1306                 die(_("error processing shallow info: %d"), reader->status);
1307
1308         if (args->deepen || unshallow_received) {
1309                 /*
1310                  * Treat these as shallow lines caused by our depth settings.
1311                  * In v0, these lines cannot cause refs to be rejected; do the
1312                  * same.
1313                  */
1314                 int i;
1315
1316                 for (i = 0; i < shallows->nr; i++)
1317                         register_shallow(the_repository, &shallows->oid[i]);
1318                 setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
1319                                         NULL);
1320                 args->deepen = 1;
1321         } else if (shallows->nr) {
1322                 /*
1323                  * Treat these as shallow lines caused by the remote being
1324                  * shallow. In v0, remote refs that reach these objects are
1325                  * rejected (unless --update-shallow is set); do the same.
1326                  */
1327                 prepare_shallow_info(si, shallows);
1328                 if (si->nr_ours || si->nr_theirs)
1329                         alternate_shallow_file =
1330                                 setup_temporary_shallow(si->shallow);
1331                 else
1332                         alternate_shallow_file = NULL;
1333         } else {
1334                 alternate_shallow_file = NULL;
1335         }
1336 }
1337
1338 static int cmp_name_ref(const void *name, const void *ref)
1339 {
1340         return strcmp(name, (*(struct ref **)ref)->name);
1341 }
1342
1343 static void receive_wanted_refs(struct packet_reader *reader,
1344                                 struct ref **sought, int nr_sought)
1345 {
1346         process_section_header(reader, "wanted-refs", 0);
1347         while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
1348                 struct object_id oid;
1349                 const char *end;
1350                 struct ref **found;
1351
1352                 if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ')
1353                         die(_("expected wanted-ref, got '%s'"), reader->line);
1354
1355                 found = bsearch(end, sought, nr_sought, sizeof(*sought),
1356                                 cmp_name_ref);
1357                 if (!found)
1358                         die(_("unexpected wanted-ref: '%s'"), reader->line);
1359                 oidcpy(&(*found)->old_oid, &oid);
1360         }
1361
1362         if (reader->status != PACKET_READ_DELIM)
1363                 die(_("error processing wanted refs: %d"), reader->status);
1364 }
1365
1366 enum fetch_state {
1367         FETCH_CHECK_LOCAL = 0,
1368         FETCH_SEND_REQUEST,
1369         FETCH_PROCESS_ACKS,
1370         FETCH_GET_PACK,
1371         FETCH_DONE,
1372 };
1373
1374 static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
1375                                     int fd[2],
1376                                     const struct ref *orig_ref,
1377                                     struct ref **sought, int nr_sought,
1378                                     struct oid_array *shallows,
1379                                     struct shallow_info *si,
1380                                     char **pack_lockfile)
1381 {
1382         struct ref *ref = copy_ref_list(orig_ref);
1383         enum fetch_state state = FETCH_CHECK_LOCAL;
1384         struct oidset common = OIDSET_INIT;
1385         struct packet_reader reader;
1386         int in_vain = 0;
1387         int haves_to_send = INITIAL_FLUSH;
1388         struct fetch_negotiator negotiator;
1389         fetch_negotiator_init(&negotiator, negotiation_algorithm);
1390         packet_reader_init(&reader, fd[0], NULL, 0,
1391                            PACKET_READ_CHOMP_NEWLINE |
1392                            PACKET_READ_DIE_ON_ERR_PACKET);
1393         if (git_env_bool("GIT_TEST_SIDEBAND_ALL", 1) &&
1394             server_supports_feature("fetch", "sideband-all", 0)) {
1395                 reader.use_sideband = 1;
1396                 reader.me = "fetch-pack";
1397         }
1398
1399         while (state != FETCH_DONE) {
1400                 switch (state) {
1401                 case FETCH_CHECK_LOCAL:
1402                         sort_ref_list(&ref, ref_compare_name);
1403                         QSORT(sought, nr_sought, cmp_ref_by_name);
1404
1405                         /* v2 supports these by default */
1406                         allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
1407                         use_sideband = 2;
1408                         if (args->depth > 0 || args->deepen_since || args->deepen_not)
1409                                 args->deepen = 1;
1410
1411                         /* Filter 'ref' by 'sought' and those that aren't local */
1412                         if (!args->no_dependents) {
1413                                 mark_complete_and_common_ref(&negotiator, args, &ref);
1414                                 filter_refs(args, &ref, sought, nr_sought);
1415                                 if (everything_local(args, &ref))
1416                                         state = FETCH_DONE;
1417                                 else
1418                                         state = FETCH_SEND_REQUEST;
1419
1420                                 mark_tips(&negotiator, args->negotiation_tips);
1421                                 for_each_cached_alternate(&negotiator,
1422                                                           insert_one_alternate_object);
1423                         } else {
1424                                 filter_refs(args, &ref, sought, nr_sought);
1425                                 state = FETCH_SEND_REQUEST;
1426                         }
1427                         break;
1428                 case FETCH_SEND_REQUEST:
1429                         if (send_fetch_request(&negotiator, fd[1], args, ref,
1430                                                &common,
1431                                                &haves_to_send, &in_vain,
1432                                                reader.use_sideband))
1433                                 state = FETCH_GET_PACK;
1434                         else
1435                                 state = FETCH_PROCESS_ACKS;
1436                         break;
1437                 case FETCH_PROCESS_ACKS:
1438                         /* Process ACKs/NAKs */
1439                         switch (process_acks(&negotiator, &reader, &common)) {
1440                         case 2:
1441                                 state = FETCH_GET_PACK;
1442                                 break;
1443                         case 1:
1444                                 in_vain = 0;
1445                                 /* fallthrough */
1446                         default:
1447                                 state = FETCH_SEND_REQUEST;
1448                                 break;
1449                         }
1450                         break;
1451                 case FETCH_GET_PACK:
1452                         /* Check for shallow-info section */
1453                         if (process_section_header(&reader, "shallow-info", 1))
1454                                 receive_shallow_info(args, &reader, shallows, si);
1455
1456                         if (process_section_header(&reader, "wanted-refs", 1))
1457                                 receive_wanted_refs(&reader, sought, nr_sought);
1458
1459                         /* get the pack */
1460                         process_section_header(&reader, "packfile", 0);
1461                         if (get_pack(args, fd, pack_lockfile))
1462                                 die(_("git fetch-pack: fetch failed."));
1463
1464                         state = FETCH_DONE;
1465                         break;
1466                 case FETCH_DONE:
1467                         continue;
1468                 }
1469         }
1470
1471         negotiator.release(&negotiator);
1472         oidset_clear(&common);
1473         return ref;
1474 }
1475
1476 static int fetch_pack_config_cb(const char *var, const char *value, void *cb)
1477 {
1478         if (strcmp(var, "fetch.fsck.skiplist") == 0) {
1479                 const char *path;
1480
1481                 if (git_config_pathname(&path, var, value))
1482                         return 1;
1483                 strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
1484                         fsck_msg_types.len ? ',' : '=', path);
1485                 free((char *)path);
1486                 return 0;
1487         }
1488
1489         if (skip_prefix(var, "fetch.fsck.", &var)) {
1490                 if (is_valid_msg_type(var, value))
1491                         strbuf_addf(&fsck_msg_types, "%c%s=%s",
1492                                 fsck_msg_types.len ? ',' : '=', var, value);
1493                 else
1494                         warning("Skipping unknown msg id '%s'", var);
1495                 return 0;
1496         }
1497
1498         return git_default_config(var, value, cb);
1499 }
1500
1501 static void fetch_pack_config(void)
1502 {
1503         git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
1504         git_config_get_int("transfer.unpacklimit", &transfer_unpack_limit);
1505         git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
1506         git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
1507         git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
1508         git_config_get_string("fetch.negotiationalgorithm",
1509                               &negotiation_algorithm);
1510
1511         git_config(fetch_pack_config_cb, NULL);
1512 }
1513
1514 static void fetch_pack_setup(void)
1515 {
1516         static int did_setup;
1517         if (did_setup)
1518                 return;
1519         fetch_pack_config();
1520         if (0 <= transfer_unpack_limit)
1521                 unpack_limit = transfer_unpack_limit;
1522         else if (0 <= fetch_unpack_limit)
1523                 unpack_limit = fetch_unpack_limit;
1524         did_setup = 1;
1525 }
1526
1527 static int remove_duplicates_in_refs(struct ref **ref, int nr)
1528 {
1529         struct string_list names = STRING_LIST_INIT_NODUP;
1530         int src, dst;
1531
1532         for (src = dst = 0; src < nr; src++) {
1533                 struct string_list_item *item;
1534                 item = string_list_insert(&names, ref[src]->name);
1535                 if (item->util)
1536                         continue; /* already have it */
1537                 item->util = ref[src];
1538                 if (src != dst)
1539                         ref[dst] = ref[src];
1540                 dst++;
1541         }
1542         for (src = dst; src < nr; src++)
1543                 ref[src] = NULL;
1544         string_list_clear(&names, 0);
1545         return dst;
1546 }
1547
1548 static void update_shallow(struct fetch_pack_args *args,
1549                            struct ref **sought, int nr_sought,
1550                            struct shallow_info *si)
1551 {
1552         struct oid_array ref = OID_ARRAY_INIT;
1553         int *status;
1554         int i;
1555
1556         if (args->deepen && alternate_shallow_file) {
1557                 if (*alternate_shallow_file == '\0') { /* --unshallow */
1558                         unlink_or_warn(git_path_shallow(the_repository));
1559                         rollback_lock_file(&shallow_lock);
1560                 } else
1561                         commit_lock_file(&shallow_lock);
1562                 alternate_shallow_file = NULL;
1563                 return;
1564         }
1565
1566         if (!si->shallow || !si->shallow->nr)
1567                 return;
1568
1569         if (args->cloning) {
1570                 /*
1571                  * remote is shallow, but this is a clone, there are
1572                  * no objects in repo to worry about. Accept any
1573                  * shallow points that exist in the pack (iow in repo
1574                  * after get_pack() and reprepare_packed_git())
1575                  */
1576                 struct oid_array extra = OID_ARRAY_INIT;
1577                 struct object_id *oid = si->shallow->oid;
1578                 for (i = 0; i < si->shallow->nr; i++)
1579                         if (has_object_file(&oid[i]))
1580                                 oid_array_append(&extra, &oid[i]);
1581                 if (extra.nr) {
1582                         setup_alternate_shallow(&shallow_lock,
1583                                                 &alternate_shallow_file,
1584                                                 &extra);
1585                         commit_lock_file(&shallow_lock);
1586                         alternate_shallow_file = NULL;
1587                 }
1588                 oid_array_clear(&extra);
1589                 return;
1590         }
1591
1592         if (!si->nr_ours && !si->nr_theirs)
1593                 return;
1594
1595         remove_nonexistent_theirs_shallow(si);
1596         if (!si->nr_ours && !si->nr_theirs)
1597                 return;
1598         for (i = 0; i < nr_sought; i++)
1599                 oid_array_append(&ref, &sought[i]->old_oid);
1600         si->ref = &ref;
1601
1602         if (args->update_shallow) {
1603                 /*
1604                  * remote is also shallow, .git/shallow may be updated
1605                  * so all refs can be accepted. Make sure we only add
1606                  * shallow roots that are actually reachable from new
1607                  * refs.
1608                  */
1609                 struct oid_array extra = OID_ARRAY_INIT;
1610                 struct object_id *oid = si->shallow->oid;
1611                 assign_shallow_commits_to_refs(si, NULL, NULL);
1612                 if (!si->nr_ours && !si->nr_theirs) {
1613                         oid_array_clear(&ref);
1614                         return;
1615                 }
1616                 for (i = 0; i < si->nr_ours; i++)
1617                         oid_array_append(&extra, &oid[si->ours[i]]);
1618                 for (i = 0; i < si->nr_theirs; i++)
1619                         oid_array_append(&extra, &oid[si->theirs[i]]);
1620                 setup_alternate_shallow(&shallow_lock,
1621                                         &alternate_shallow_file,
1622                                         &extra);
1623                 commit_lock_file(&shallow_lock);
1624                 oid_array_clear(&extra);
1625                 oid_array_clear(&ref);
1626                 alternate_shallow_file = NULL;
1627                 return;
1628         }
1629
1630         /*
1631          * remote is also shallow, check what ref is safe to update
1632          * without updating .git/shallow
1633          */
1634         status = xcalloc(nr_sought, sizeof(*status));
1635         assign_shallow_commits_to_refs(si, NULL, status);
1636         if (si->nr_ours || si->nr_theirs) {
1637                 for (i = 0; i < nr_sought; i++)
1638                         if (status[i])
1639                                 sought[i]->status = REF_STATUS_REJECT_SHALLOW;
1640         }
1641         free(status);
1642         oid_array_clear(&ref);
1643 }
1644
1645 static int iterate_ref_map(void *cb_data, struct object_id *oid)
1646 {
1647         struct ref **rm = cb_data;
1648         struct ref *ref = *rm;
1649
1650         if (!ref)
1651                 return -1; /* end of the list */
1652         *rm = ref->next;
1653         oidcpy(oid, &ref->old_oid);
1654         return 0;
1655 }
1656
1657 struct ref *fetch_pack(struct fetch_pack_args *args,
1658                        int fd[],
1659                        const struct ref *ref,
1660                        struct ref **sought, int nr_sought,
1661                        struct oid_array *shallow,
1662                        char **pack_lockfile,
1663                        enum protocol_version version)
1664 {
1665         struct ref *ref_cpy;
1666         struct shallow_info si;
1667         struct oid_array shallows_scratch = OID_ARRAY_INIT;
1668
1669         fetch_pack_setup();
1670         if (nr_sought)
1671                 nr_sought = remove_duplicates_in_refs(sought, nr_sought);
1672
1673         if (args->no_dependents && !args->filter_options.choice) {
1674                 /*
1675                  * The protocol does not support requesting that only the
1676                  * wanted objects be sent, so approximate this by setting a
1677                  * "blob:none" filter if no filter is already set. This works
1678                  * for all object types: note that wanted blobs will still be
1679                  * sent because they are directly specified as a "want".
1680                  *
1681                  * NEEDSWORK: Add an option in the protocol to request that
1682                  * only the wanted objects be sent, and implement it.
1683                  */
1684                 parse_list_objects_filter(&args->filter_options, "blob:none");
1685         }
1686
1687         if (version != protocol_v2 && !ref) {
1688                 packet_flush(fd[1]);
1689                 die(_("no matching remote head"));
1690         }
1691         if (version == protocol_v2) {
1692                 if (shallow->nr)
1693                         BUG("Protocol V2 does not provide shallows at this point in the fetch");
1694                 memset(&si, 0, sizeof(si));
1695                 ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
1696                                            &shallows_scratch, &si,
1697                                            pack_lockfile);
1698         } else {
1699                 prepare_shallow_info(&si, shallow);
1700                 ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
1701                                         &si, pack_lockfile);
1702         }
1703         reprepare_packed_git(the_repository);
1704
1705         if (!args->cloning && args->deepen) {
1706                 struct check_connected_options opt = CHECK_CONNECTED_INIT;
1707                 struct ref *iterator = ref_cpy;
1708                 opt.shallow_file = alternate_shallow_file;
1709                 if (args->deepen)
1710                         opt.is_deepening_fetch = 1;
1711                 if (check_connected(iterate_ref_map, &iterator, &opt)) {
1712                         error(_("remote did not send all necessary objects"));
1713                         free_refs(ref_cpy);
1714                         ref_cpy = NULL;
1715                         rollback_lock_file(&shallow_lock);
1716                         goto cleanup;
1717                 }
1718                 args->connectivity_checked = 1;
1719         }
1720
1721         update_shallow(args, sought, nr_sought, &si);
1722 cleanup:
1723         clear_shallow_info(&si);
1724         oid_array_clear(&shallows_scratch);
1725         return ref_cpy;
1726 }
1727
1728 int report_unmatched_refs(struct ref **sought, int nr_sought)
1729 {
1730         int i, ret = 0;
1731
1732         for (i = 0; i < nr_sought; i++) {
1733                 if (!sought[i])
1734                         continue;
1735                 switch (sought[i]->match_status) {
1736                 case REF_MATCHED:
1737                         continue;
1738                 case REF_NOT_MATCHED:
1739                         error(_("no such remote ref %s"), sought[i]->name);
1740                         break;
1741                 case REF_UNADVERTISED_NOT_ALLOWED:
1742                         error(_("Server does not allow request for unadvertised object %s"),
1743                               sought[i]->name);
1744                         break;
1745                 }
1746                 ret = 1;
1747         }
1748         return ret;
1749 }