X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=fetch-pack.c;h=876f90c759a09334bb4a47575c236d27f2887b98;hb=a78305ffbca58e49a7cdad901df0ae779bbed8fb;hp=afb8b05024823981be9bedfaa70f7301c6f7076c;hpb=89d3f2b6c0acc1c82ff866472d3760b2c62f587a;p=platform%2Fupstream%2Fgit.git

diff --git a/fetch-pack.c b/fetch-pack.c
index afb8b05..876f90c 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -1,10 +1,12 @@
 #include "cache.h"
+#include "repository.h"
+#include "config.h"
 #include "lockfile.h"
 #include "refs.h"
 #include "pkt-line.h"
 #include "commit.h"
 #include "tag.h"
-#include "exec_cmd.h"
+#include "exec-cmd.h"
 #include "pack.h"
 #include "sideband.h"
 #include "fetch-pack.h"
@@ -13,8 +15,14 @@
 #include "connect.h"
 #include "transport.h"
 #include "version.h"
-#include "prio-queue.h"
-#include "sha1-array.h"
+#include "oid-array.h"
+#include "oidset.h"
+#include "packfile.h"
+#include "object-store.h"
+#include "connected.h"
+#include "fetch-negotiator.h"
+#include "fsck.h"
+#include "shallow.h"
 
 static int transfer_unpack_limit = -1;
 static int fetch_unpack_limit = -1;
@@ -26,18 +34,16 @@ static int deepen_not_ok;
 static int fetch_fsck_objects = -1;
 static int transfer_fsck_objects = -1;
 static int agent_supported;
-static struct lock_file shallow_lock;
+static int server_supports_filtering;
+static int advertise_sid;
+static struct shallow_lock shallow_lock;
 static const char *alternate_shallow_file;
+static struct strbuf fsck_msg_types = STRBUF_INIT;
+static struct string_list uri_protocols = STRING_LIST_INIT_DUP;
 
 /* Remember to update object flag allocation in object.h */
 #define COMPLETE	(1U << 0)
-#define COMMON		(1U << 1)
-#define COMMON_REF	(1U << 2)
-#define SEEN		(1U << 3)
-#define POPPED		(1U << 4)
-#define ALTERNATE	(1U << 5)
-
-static int marked;
+#define ALTERNATE	(1U << 1)
 
 /*
  * After sending this many "have"s if we do not get any new ACK , we
@@ -45,8 +51,7 @@ static int marked;
  */
 #define MAX_IN_VAIN 256
 
-static struct prio_queue rev_list = { compare_commits_by_commit_date };
-static int non_common_revs, multi_ack, use_sideband;
+static int multi_ack, use_sideband;
 /* Allow specifying sha1 if it is a ref tip. */
 #define ALLOW_TIP_SHA1	01
 /* Allow request of a sha1 if it is reachable from a ref (possibly hidden ref). */
@@ -73,12 +78,11 @@ struct alternate_object_cache {
 	size_t nr, alloc;
 };
 
-static void cache_one_alternate(const char *refname,
-				const struct object_id *oid,
+static void cache_one_alternate(const struct object_id *oid,
 				void *vcache)
 {
 	struct alternate_object_cache *cache = vcache;
-	struct object *obj = parse_object(oid->hash);
+	struct object *obj = parse_object(the_repository, oid);
 
 	if (!obj || (obj->flags & ALTERNATE))
 		return;
@@ -88,7 +92,9 @@ static void cache_one_alternate(const char *refname,
 	cache->items[cache->nr++] = obj;
 }
 
-static void for_each_cached_alternate(void (*cb)(struct object *))
+static void for_each_cached_alternate(struct fetch_negotiator *negotiator,
+				      void (*cb)(struct fetch_negotiator *,
+						 struct object *))
 {
 	static int initialized;
 	static struct alternate_object_cache cache;
@@ -100,129 +106,51 @@ static void for_each_cached_alternate(void (*cb)(struct object *))
 	}
 
 	for (i = 0; i < cache.nr; i++)
-		cb(cache.items[i]);
+		cb(negotiator, cache.items[i]);
 }
 
-static void rev_list_push(struct commit *commit, int mark)
+static struct commit *deref_without_lazy_fetch(const struct object_id *oid,
+					       int mark_tags_complete)
 {
-	if (!(commit->object.flags & mark)) {
-		commit->object.flags |= mark;
-
-		if (parse_commit(commit))
-			return;
+	enum object_type type;
+	struct object_info info = { .typep = &type };
 
-		prio_queue_put(&rev_list, commit);
-
-		if (!(commit->object.flags & COMMON))
-			non_common_revs++;
+	while (1) {
+		if (oid_object_info_extended(the_repository, oid, &info,
+					     OBJECT_INFO_SKIP_FETCH_OBJECT | OBJECT_INFO_QUICK))
+			return NULL;
+		if (type == OBJ_TAG) {
+			struct tag *tag = (struct tag *)
+				parse_object(the_repository, oid);
+
+			if (!tag->tagged)
+				return NULL;
+			if (mark_tags_complete)
+				tag->object.flags |= COMPLETE;
+			oid = &tag->tagged->oid;
+		} else {
+			break;
+		}
 	}
+	if (type == OBJ_COMMIT)
+		return (struct commit *) parse_object(the_repository, oid);
+	return NULL;
 }
 
-static int rev_list_insert_ref(const char *refname, const unsigned char *sha1)
+static int rev_list_insert_ref(struct fetch_negotiator *negotiator,
+			       const struct object_id *oid)
 {
-	struct object *o = deref_tag(parse_object(sha1), refname, 0);
-
-	if (o && o->type == OBJ_COMMIT)
-		rev_list_push((struct commit *)o, SEEN);
+	struct commit *c = deref_without_lazy_fetch(oid, 0);
 
+	if (c)
+		negotiator->add_tip(negotiator, c);
 	return 0;
 }
 
 static int rev_list_insert_ref_oid(const char *refname, const struct object_id *oid,
 				   int flag, void *cb_data)
 {
-	return rev_list_insert_ref(refname, oid->hash);
-}
-
-static int clear_marks(const char *refname, const struct object_id *oid,
-		       int flag, void *cb_data)
-{
-	struct object *o = deref_tag(parse_object(oid->hash), refname, 0);
-
-	if (o && o->type == OBJ_COMMIT)
-		clear_commit_marks((struct commit *)o,
-				   COMMON | COMMON_REF | SEEN | POPPED);
-	return 0;
-}
-
-/*
-   This function marks a rev and its ancestors as common.
-   In some cases, it is desirable to mark only the ancestors (for example
-   when only the server does not yet know that they are common).
-*/
-
-static void mark_common(struct commit *commit,
-		int ancestors_only, int dont_parse)
-{
-	if (commit != NULL && !(commit->object.flags & COMMON)) {
-		struct object *o = (struct object *)commit;
-
-		if (!ancestors_only)
-			o->flags |= COMMON;
-
-		if (!(o->flags & SEEN))
-			rev_list_push(commit, SEEN);
-		else {
-			struct commit_list *parents;
-
-			if (!ancestors_only && !(o->flags & POPPED))
-				non_common_revs--;
-			if (!o->parsed && !dont_parse)
-				if (parse_commit(commit))
-					return;
-
-			for (parents = commit->parents;
-					parents;
-					parents = parents->next)
-				mark_common(parents->item, 0, dont_parse);
-		}
-	}
-}
-
-/*
-  Get the next rev to send, ignoring the common.
-*/
-
-static const unsigned char *get_rev(void)
-{
-	struct commit *commit = NULL;
-
-	while (commit == NULL) {
-		unsigned int mark;
-		struct commit_list *parents;
-
-		if (rev_list.nr == 0 || non_common_revs == 0)
-			return NULL;
-
-		commit = prio_queue_get(&rev_list);
-		parse_commit(commit);
-		parents = commit->parents;
-
-		commit->object.flags |= POPPED;
-		if (!(commit->object.flags & COMMON))
-			non_common_revs--;
-
-		if (commit->object.flags & COMMON) {
-			/* do not send "have", and ignore ancestors */
-			commit = NULL;
-			mark = COMMON | SEEN;
-		} else if (commit->object.flags & COMMON_REF)
-			/* send "have", and ignore ancestors */
-			mark = COMMON | SEEN;
-		else
-			/* send "have", also for its ancestors */
-			mark = SEEN;
-
-		while (parents) {
-			if (!(parents->item->object.flags & SEEN))
-				rev_list_push(parents->item, mark);
-			if (mark & COMMON)
-				mark_common(parents->item, 1, 0);
-			parents = parents->next;
-		}
-	}
-
-	return commit->object.oid.hash;
+	return rev_list_insert_ref(cb_data, oid);
 }
 
 enum ack_type {
@@ -233,52 +161,54 @@ enum ack_type {
 	ACK_ready
 };
 
-static void consume_shallow_list(struct fetch_pack_args *args, int fd)
+static void consume_shallow_list(struct fetch_pack_args *args,
+				 struct packet_reader *reader)
 {
 	if (args->stateless_rpc && args->deepen) {
 		/* If we sent a depth we will get back "duplicate"
 		 * shallow and unshallow commands every time there
 		 * is a block of have lines exchanged.
 		 */
-		char *line;
-		while ((line = packet_read_line(fd, NULL))) {
-			if (starts_with(line, "shallow "))
+		while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
+			if (starts_with(reader->line, "shallow "))
 				continue;
-			if (starts_with(line, "unshallow "))
+			if (starts_with(reader->line, "unshallow "))
 				continue;
 			die(_("git fetch-pack: expected shallow list"));
 		}
+		if (reader->status != PACKET_READ_FLUSH)
+			die(_("git fetch-pack: expected a flush packet after shallow list"));
 	}
 }
 
-static enum ack_type get_ack(int fd, unsigned char *result_sha1)
+static enum ack_type get_ack(struct packet_reader *reader,
+			     struct object_id *result_oid)
 {
 	int len;
-	char *line = packet_read_line(fd, &len);
 	const char *arg;
 
-	if (!len)
-		die(_("git fetch-pack: expected ACK/NAK, got EOF"));
-	if (!strcmp(line, "NAK"))
+	if (packet_reader_read(reader) != PACKET_READ_NORMAL)
+		die(_("git fetch-pack: expected ACK/NAK, got a flush packet"));
+	len = reader->pktlen;
+
+	if (!strcmp(reader->line, "NAK"))
 		return NAK;
-	if (skip_prefix(line, "ACK ", &arg)) {
-		if (!get_sha1_hex(arg, result_sha1)) {
-			arg += 40;
-			len -= arg - line;
+	if (skip_prefix(reader->line, "ACK ", &arg)) {
+		const char *p;
+		if (!parse_oid_hex(arg, result_oid, &p)) {
+			len -= p - reader->line;
 			if (len < 1)
 				return ACK;
-			if (strstr(arg, "continue"))
+			if (strstr(p, "continue"))
 				return ACK_continue;
-			if (strstr(arg, "common"))
+			if (strstr(p, "common"))
 				return ACK_common;
-			if (strstr(arg, "ready"))
+			if (strstr(p, "ready"))
 				return ACK_ready;
 			return ACK;
 		}
 	}
-	if (skip_prefix(line, "ERR ", &arg))
-		die(_("remote error: %s"), arg);
-	die(_("git fetch-pack: expected ACK/NAK, got '%s'"), line);
+	die(_("git fetch-pack: expected ACK/NAK, got '%s'"), reader->line);
 }
 
 static void send_request(struct fetch_pack_args *args,
@@ -287,22 +217,25 @@ static void send_request(struct fetch_pack_args *args,
 	if (args->stateless_rpc) {
 		send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
 		packet_flush(fd);
-	} else
-		write_or_die(fd, buf->buf, buf->len);
+	} else {
+		if (write_in_full(fd, buf->buf, buf->len) < 0)
+			die_errno(_("unable to write to remote"));
+	}
 }
 
-static void insert_one_alternate_object(struct object *obj)
+static void insert_one_alternate_object(struct fetch_negotiator *negotiator,
+					struct object *obj)
 {
-	rev_list_insert_ref(NULL, obj->oid.hash);
+	rev_list_insert_ref(negotiator, &obj->oid);
 }
 
 #define INITIAL_FLUSH 16
 #define PIPESAFE_FLUSH 32
 #define LARGE_FLUSH 16384
 
-static int next_flush(struct fetch_pack_args *args, int count)
+static int next_flush(int stateless_rpc, int count)
 {
-	if (args->stateless_rpc) {
+	if (stateless_rpc) {
 		if (count < LARGE_FLUSH)
 			count <<= 1;
 		else
@@ -316,31 +249,49 @@ static int next_flush(struct fetch_pack_args *args, int count)
 	return count;
 }
 
-static int find_common(struct fetch_pack_args *args,
-		       int fd[2], unsigned char *result_sha1,
+static void mark_tips(struct fetch_negotiator *negotiator,
+		      const struct oid_array *negotiation_tips)
+{
+	int i;
+
+	if (!negotiation_tips) {
+		for_each_rawref(rev_list_insert_ref_oid, negotiator);
+		return;
+	}
+
+	for (i = 0; i < negotiation_tips->nr; i++)
+		rev_list_insert_ref(negotiator, &negotiation_tips->oid[i]);
+	return;
+}
+
+static int find_common(struct fetch_negotiator *negotiator,
+		       struct fetch_pack_args *args,
+		       int fd[2], struct object_id *result_oid,
 		       struct ref *refs)
 {
 	int fetching;
 	int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
-	const unsigned char *sha1;
+	const struct object_id *oid;
 	unsigned in_vain = 0;
 	int got_continue = 0;
 	int got_ready = 0;
 	struct strbuf req_buf = STRBUF_INIT;
 	size_t state_len = 0;
+	struct packet_reader reader;
 
 	if (args->stateless_rpc && multi_ack == 1)
 		die(_("--stateless-rpc requires multi_ack_detailed"));
-	if (marked)
-		for_each_ref(clear_marks, NULL);
-	marked = 1;
 
-	for_each_ref(rev_list_insert_ref_oid, NULL);
-	for_each_cached_alternate(insert_one_alternate_object);
+	packet_reader_init(&reader, fd[0], NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_DIE_ON_ERR_PACKET);
+
+	mark_tips(negotiator, args->negotiation_tips);
+	for_each_cached_alternate(negotiator, insert_one_alternate_object);
 
 	fetching = 0;
 	for ( ; refs ; refs = refs->next) {
-		unsigned char *remote = refs->old_oid.hash;
+		struct object_id *remote = &refs->old_oid;
 		const char *remote_hex;
 		struct object *o;
 
@@ -354,12 +305,12 @@ static int find_common(struct fetch_pack_args *args,
 		 * interested in the case we *know* the object is
 		 * reachable and we have already scanned it.
 		 */
-		if (((o = lookup_object(remote)) != NULL) &&
+		if (((o = lookup_object(the_repository, remote)) != NULL) &&
 				(o->flags & COMPLETE)) {
 			continue;
 		}
 
-		remote_hex = sha1_to_hex(remote);
+		remote_hex = oid_to_hex(remote);
 		if (!fetching) {
 			struct strbuf c = STRBUF_INIT;
 			if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
@@ -376,6 +327,10 @@ static int find_common(struct fetch_pack_args *args,
 			if (deepen_not_ok)      strbuf_addstr(&c, " deepen-not");
 			if (agent_supported)    strbuf_addf(&c, " agent=%s",
 							    git_user_agent_sanitized());
+			if (advertise_sid)
+				strbuf_addf(&c, " session-id=%s", trace2_session_id());
+			if (args->filter_options.choice)
+				strbuf_addstr(&c, " filter");
 			packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
 			strbuf_release(&c);
 		} else
@@ -389,13 +344,13 @@ static int find_common(struct fetch_pack_args *args,
 		return 1;
 	}
 
-	if (is_repository_shallow())
+	if (is_repository_shallow(the_repository))
 		write_shallow_commits(&req_buf, 1, NULL);
 	if (args->depth > 0)
 		packet_buf_write(&req_buf, "deepen %d", args->depth);
 	if (args->deepen_since) {
-		unsigned long max_age = approxidate(args->deepen_since);
-		packet_buf_write(&req_buf, "deepen-since %lu", max_age);
+		timestamp_t max_age = approxidate(args->deepen_since);
+		packet_buf_write(&req_buf, "deepen-since %"PRItime, max_age);
 	}
 	if (args->deepen_not) {
 		int i;
@@ -404,35 +359,39 @@ static int find_common(struct fetch_pack_args *args,
 			packet_buf_write(&req_buf, "deepen-not %s", s->string);
 		}
 	}
+	if (server_supports_filtering && args->filter_options.choice) {
+		const char *spec =
+			expand_list_objects_filter_spec(&args->filter_options);
+		packet_buf_write(&req_buf, "filter %s", spec);
+	}
 	packet_buf_flush(&req_buf);
 	state_len = req_buf.len;
 
 	if (args->deepen) {
-		char *line;
 		const char *arg;
-		unsigned char sha1[20];
+		struct object_id oid;
 
 		send_request(args, fd[1], &req_buf);
-		while ((line = packet_read_line(fd[0], NULL))) {
-			if (skip_prefix(line, "shallow ", &arg)) {
-				if (get_sha1_hex(arg, sha1))
-					die(_("invalid shallow line: %s"), line);
-				register_shallow(sha1);
+		while (packet_reader_read(&reader) == PACKET_READ_NORMAL) {
+			if (skip_prefix(reader.line, "shallow ", &arg)) {
+				if (get_oid_hex(arg, &oid))
+					die(_("invalid shallow line: %s"), reader.line);
+				register_shallow(the_repository, &oid);
 				continue;
 			}
-			if (skip_prefix(line, "unshallow ", &arg)) {
-				if (get_sha1_hex(arg, sha1))
-					die(_("invalid unshallow line: %s"), line);
-				if (!lookup_object(sha1))
-					die(_("object not found: %s"), line);
+			if (skip_prefix(reader.line, "unshallow ", &arg)) {
+				if (get_oid_hex(arg, &oid))
+					die(_("invalid unshallow line: %s"), reader.line);
+				if (!lookup_object(the_repository, &oid))
+					die(_("object not found: %s"), reader.line);
 				/* make sure that it is parsed as shallow */
-				if (!parse_object(sha1))
-					die(_("error in object: %s"), line);
-				if (unregister_shallow(sha1))
-					die(_("no shallow found: %s"), line);
+				if (!parse_object(the_repository, &oid))
+					die(_("error in object: %s"), reader.line);
+				if (unregister_shallow(&oid))
+					die(_("no shallow found: %s"), reader.line);
 				continue;
 			}
-			die(_("expected shallow/unshallow, got %s"), line);
+			die(_("expected shallow/unshallow, got %s"), reader.line);
 		}
 	} else if (!args->stateless_rpc)
 		send_request(args, fd[1], &req_buf);
@@ -445,11 +404,12 @@ static int find_common(struct fetch_pack_args *args,
 		state_len = 0;
 	}
 
+	trace2_region_enter("fetch-pack", "negotiation_v0_v1", the_repository);
 	flushes = 0;
 	retval = -1;
-	while ((sha1 = get_rev())) {
-		packet_buf_write(&req_buf, "have %s\n", sha1_to_hex(sha1));
-		print_verbose(args, "have %s", sha1_to_hex(sha1));
+	while ((oid = negotiator->next(negotiator))) {
+		packet_buf_write(&req_buf, "have %s\n", oid_to_hex(oid));
+		print_verbose(args, "have %s", oid_to_hex(oid));
 		in_vain++;
 		if (flush_at <= ++count) {
 			int ack;
@@ -458,7 +418,7 @@ static int find_common(struct fetch_pack_args *args,
 			send_request(args, fd[1], &req_buf);
 			strbuf_setlen(&req_buf, state_len);
 			flushes++;
-			flush_at = next_flush(args, count);
+			flush_at = next_flush(args->stateless_rpc, count);
 
 			/*
 			 * We keep one window "ahead" of the other side, and
@@ -467,12 +427,12 @@ static int find_common(struct fetch_pack_args *args,
 			if (!args->stateless_rpc && count == INITIAL_FLUSH)
 				continue;
 
-			consume_shallow_list(args, fd[0]);
+			consume_shallow_list(args, &reader);
 			do {
-				ack = get_ack(fd[0], result_sha1);
+				ack = get_ack(&reader, result_oid);
 				if (ack)
 					print_verbose(args, _("got %s %d %s"), "ack",
-						      ack, sha1_to_hex(result_sha1));
+						      ack, oid_to_hex(result_oid));
 				switch (ack) {
 				case ACK:
 					flushes = 0;
@@ -483,17 +443,21 @@ static int find_common(struct fetch_pack_args *args,
 				case ACK_ready:
 				case ACK_continue: {
 					struct commit *commit =
-						lookup_commit(result_sha1);
+						lookup_commit(the_repository,
+							      result_oid);
+					int was_common;
+
 					if (!commit)
-						die(_("invalid commit %s"), sha1_to_hex(result_sha1));
+						die(_("invalid commit %s"), oid_to_hex(result_oid));
+					was_common = negotiator->ack(negotiator, commit);
 					if (args->stateless_rpc
 					 && ack == ACK_common
-					 && !(commit->object.flags & COMMON)) {
+					 && !was_common) {
 						/* We need to replay the have for this object
 						 * on the next RPC request so the peer knows
 						 * it is in common with us.
 						 */
-						const char *hex = sha1_to_hex(result_sha1);
+						const char *hex = oid_to_hex(result_oid);
 						packet_buf_write(&req_buf, "have %s\n", hex);
 						state_len = req_buf.len;
 						/*
@@ -505,13 +469,10 @@ static int find_common(struct fetch_pack_args *args,
 					} else if (!args->stateless_rpc
 						   || ack != ACK_common)
 						in_vain = 0;
-					mark_common(commit, 0, 1);
 					retval = 0;
 					got_continue = 1;
-					if (ack == ACK_ready) {
-						clear_prio_queue(&rev_list);
+					if (ack == ACK_ready)
 						got_ready = 1;
-					}
 					break;
 					}
 				}
@@ -521,9 +482,12 @@ static int find_common(struct fetch_pack_args *args,
 				print_verbose(args, _("giving up"));
 				break; /* give up */
 			}
+			if (got_ready)
+				break;
 		}
 	}
 done:
+	trace2_region_leave("fetch-pack", "negotiation_v0_v1", the_repository);
 	if (!got_ready || !no_done) {
 		packet_buf_write(&req_buf, "done\n");
 		send_request(args, fd[1], &req_buf);
@@ -536,12 +500,12 @@ done:
 	strbuf_release(&req_buf);
 
 	if (!got_ready || !no_done)
-		consume_shallow_list(args, fd[0]);
+		consume_shallow_list(args, &reader);
 	while (flushes || multi_ack) {
-		int ack = get_ack(fd[0], result_sha1);
+		int ack = get_ack(&reader, result_oid);
 		if (ack) {
 			print_verbose(args, _("got %s (%d) %s"), "ack",
-				      ack, sha1_to_hex(result_sha1));
+				      ack, oid_to_hex(result_oid));
 			if (ack == ACK)
 				return 0;
 			multi_ack = 1;
@@ -555,23 +519,13 @@ done:
 
 static struct commit_list *complete;
 
-static int mark_complete(const unsigned char *sha1)
+static int mark_complete(const struct object_id *oid)
 {
-	struct object *o = parse_object(sha1);
-
-	while (o && o->type == OBJ_TAG) {
-		struct tag *t = (struct tag *) o;
-		if (!t->tagged)
-			break; /* broken repository */
-		o->flags |= COMPLETE;
-		o = parse_object(t->tagged->oid.hash);
-	}
-	if (o && o->type == OBJ_COMMIT) {
-		struct commit *commit = (struct commit *)o;
-		if (!(commit->object.flags & COMPLETE)) {
-			commit->object.flags |= COMPLETE;
-			commit_list_insert(commit, &complete);
-		}
+	struct commit *commit = deref_without_lazy_fetch(oid, 1);
+
+	if (commit && !(commit->object.flags & COMPLETE)) {
+		commit->object.flags |= COMPLETE;
+		commit_list_insert(commit, &complete);
 	}
 	return 0;
 }
@@ -579,11 +533,11 @@ static int mark_complete(const unsigned char *sha1)
 static int mark_complete_oid(const char *refname, const struct object_id *oid,
 			     int flag, void *cb_data)
 {
-	return mark_complete(oid->hash);
+	return mark_complete(oid);
 }
 
 static void mark_recent_complete_commits(struct fetch_pack_args *args,
-					 unsigned long cutoff)
+					 timestamp_t cutoff)
 {
 	while (complete && cutoff <= complete->item->date) {
 		print_verbose(args, _("Marking %s as complete"),
@@ -592,14 +546,34 @@ static void mark_recent_complete_commits(struct fetch_pack_args *args,
 	}
 }
 
+static void add_refs_to_oidset(struct oidset *oids, struct ref *refs)
+{
+	for (; refs; refs = refs->next)
+		oidset_insert(oids, &refs->old_oid);
+}
+
+static int is_unmatched_ref(const struct ref *ref)
+{
+	struct object_id oid;
+	const char *p;
+	return	ref->match_status == REF_NOT_MATCHED &&
+		!parse_oid_hex(ref->name, &oid, &p) &&
+		*p == '\0' &&
+		oideq(&oid, &ref->old_oid);
+}
+
 static void filter_refs(struct fetch_pack_args *args,
 			struct ref **refs,
 			struct ref **sought, int nr_sought)
 {
 	struct ref *newlist = NULL;
 	struct ref **newtail = &newlist;
+	struct ref *unmatched = NULL;
 	struct ref *ref, *next;
+	struct oidset tip_oids = OIDSET_INIT;
 	int i;
+	int strict = !(allow_unadvertised_object_request &
+		       (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1));
 
 	i = 0;
 	for (ref = *refs; ref; ref = next) {
@@ -607,9 +581,14 @@ static void filter_refs(struct fetch_pack_args *args,
 		next = ref->next;
 
 		if (starts_with(ref->name, "refs/") &&
-		    check_refname_format(ref->name, 0))
-			; /* trash */
-		else {
+		    check_refname_format(ref->name, 0)) {
+			/*
+			 * trash or a peeled value; do not even add it to
+			 * unmatched list
+			 */
+			free_one_ref(ref);
+			continue;
+		} else {
 			while (i < nr_sought) {
 				int cmp = strcmp(ref->name, sought[i]->name);
 				if (cmp < 0)
@@ -620,35 +599,41 @@ static void filter_refs(struct fetch_pack_args *args,
 				}
 				i++;
 			}
-		}
 
-		if (!keep && args->fetch_all &&
-		    (!args->deepen || !starts_with(ref->name, "refs/tags/")))
-			keep = 1;
+			if (!keep && args->fetch_all &&
+			    (!args->deepen || !starts_with(ref->name, "refs/tags/")))
+				keep = 1;
+		}
 
 		if (keep) {
 			*newtail = ref;
 			ref->next = NULL;
 			newtail = &ref->next;
 		} else {
-			free(ref);
+			ref->next = unmatched;
+			unmatched = ref;
+		}
+	}
+
+	if (strict) {
+		for (i = 0; i < nr_sought; i++) {
+			ref = sought[i];
+			if (!is_unmatched_ref(ref))
+				continue;
+
+			add_refs_to_oidset(&tip_oids, unmatched);
+			add_refs_to_oidset(&tip_oids, newlist);
+			break;
 		}
 	}
 
 	/* Append unmatched requests to the list */
 	for (i = 0; i < nr_sought; i++) {
-		unsigned char sha1[20];
-
 		ref = sought[i];
-		if (ref->match_status != REF_NOT_MATCHED)
-			continue;
-		if (get_sha1_hex(ref->name, sha1) ||
-		    ref->name[40] != '\0' ||
-		    hashcmp(sha1, ref->old_oid.hash))
+		if (!is_unmatched_ref(ref))
 			continue;
 
-		if ((allow_unadvertised_object_request &
-		    (ALLOW_TIP_SHA1 | ALLOW_REACHABLE_SHA1))) {
+		if (!strict || oidset_contains(&tip_oids, &ref->old_oid)) {
 			ref->match_status = REF_MATCHED;
 			*newtail = copy_ref(ref);
 			newtail = &(*newtail)->next;
@@ -656,35 +641,56 @@ static void filter_refs(struct fetch_pack_args *args,
 			ref->match_status = REF_UNADVERTISED_NOT_ALLOWED;
 		}
 	}
+
+	oidset_clear(&tip_oids);
+	free_refs(unmatched);
+
 	*refs = newlist;
 }
 
-static void mark_alternate_complete(struct object *obj)
+static void mark_alternate_complete(struct fetch_negotiator *unused,
+				    struct object *obj)
 {
-	mark_complete(obj->oid.hash);
+	mark_complete(&obj->oid);
 }
 
-static int everything_local(struct fetch_pack_args *args,
-			    struct ref **refs,
-			    struct ref **sought, int nr_sought)
+struct loose_object_iter {
+	struct oidset *loose_object_set;
+	struct ref *refs;
+};
+
+/*
+ * Mark recent commits available locally and reachable from a local ref as
+ * COMPLETE.
+ *
+ * The cutoff time for recency is determined by this heuristic: it is the
+ * earliest commit time of the objects in refs that are commits and that we know
+ * the commit time of.
+ */
+static void mark_complete_and_common_ref(struct fetch_negotiator *negotiator,
+					 struct fetch_pack_args *args,
+					 struct ref **refs)
 {
 	struct ref *ref;
-	int retval;
-	unsigned long cutoff = 0;
+	int old_save_commit_buffer = save_commit_buffer;
+	timestamp_t cutoff = 0;
 
 	save_commit_buffer = 0;
 
+	trace2_region_enter("fetch-pack", "parse_remote_refs_and_find_cutoff", NULL);
 	for (ref = *refs; ref; ref = ref->next) {
 		struct object *o;
 
-		if (!has_object_file(&ref->old_oid))
+		if (!has_object_file_with_flags(&ref->old_oid,
+						OBJECT_INFO_QUICK |
+							OBJECT_INFO_SKIP_FETCH_OBJECT))
 			continue;
-
-		o = parse_object(ref->old_oid.hash);
+		o = parse_object(the_repository, &ref->old_oid);
 		if (!o)
 			continue;
 
-		/* We already have it -- which may mean that we were
+		/*
+		 * We already have it -- which may mean that we were
 		 * in sync with the other side at some time after
 		 * that (it is OK if we guess wrong here).
 		 */
@@ -694,49 +700,65 @@ static int everything_local(struct fetch_pack_args *args,
 				cutoff = commit->date;
 		}
 	}
+	trace2_region_leave("fetch-pack", "parse_remote_refs_and_find_cutoff", NULL);
 
+	/*
+	 * This block marks all local refs as COMPLETE, and then recursively marks all
+	 * parents of those refs as COMPLETE.
+	 */
+	trace2_region_enter("fetch-pack", "mark_complete_local_refs", NULL);
 	if (!args->deepen) {
-		for_each_ref(mark_complete_oid, NULL);
-		for_each_cached_alternate(mark_alternate_complete);
+		for_each_rawref(mark_complete_oid, NULL);
+		for_each_cached_alternate(NULL, mark_alternate_complete);
 		commit_list_sort_by_date(&complete);
 		if (cutoff)
 			mark_recent_complete_commits(args, cutoff);
 	}
+	trace2_region_leave("fetch-pack", "mark_complete_local_refs", NULL);
 
 	/*
 	 * Mark all complete remote refs as common refs.
 	 * Don't mark them common yet; the server has to be told so first.
 	 */
+	trace2_region_enter("fetch-pack", "mark_common_remote_refs", NULL);
 	for (ref = *refs; ref; ref = ref->next) {
-		struct object *o = deref_tag(lookup_object(ref->old_oid.hash),
-					     NULL, 0);
+		struct commit *c = deref_without_lazy_fetch(&ref->old_oid, 0);
 
-		if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
+		if (!c || !(c->object.flags & COMPLETE))
 			continue;
 
-		if (!(o->flags & SEEN)) {
-			rev_list_push((struct commit *)o, COMMON_REF | SEEN);
-
-			mark_common((struct commit *)o, 1, 1);
-		}
+		negotiator->known_common(negotiator, c);
 	}
+	trace2_region_leave("fetch-pack", "mark_common_remote_refs", NULL);
 
-	filter_refs(args, refs, sought, nr_sought);
+	save_commit_buffer = old_save_commit_buffer;
+}
+
+/*
+ * Returns 1 if every object pointed to by the given remote refs is available
+ * locally and reachable from a local ref, and 0 otherwise.
+ */
+static int everything_local(struct fetch_pack_args *args,
+			    struct ref **refs)
+{
+	struct ref *ref;
+	int retval;
 
 	for (retval = 1, ref = *refs; ref ; ref = ref->next) {
-		const unsigned char *remote = ref->old_oid.hash;
+		const struct object_id *remote = &ref->old_oid;
 		struct object *o;
 
-		o = lookup_object(remote);
+		o = lookup_object(the_repository, remote);
 		if (!o || !(o->flags & COMPLETE)) {
 			retval = 0;
-			print_verbose(args, "want %s (%s)", sha1_to_hex(remote),
+			print_verbose(args, "want %s (%s)", oid_to_hex(remote),
 				      ref->name);
 			continue;
 		}
-		print_verbose(args, _("already have %s (%s)"), sha1_to_hex(remote),
+		print_verbose(args, _("already have %s (%s)"), oid_to_hex(remote),
 			      ref->name);
 	}
+
 	return retval;
 }
 
@@ -750,8 +772,38 @@ static int sideband_demux(int in, int out, void *data)
 	return ret;
 }
 
+static void write_promisor_file(const char *keep_name,
+				struct ref **sought, int nr_sought)
+{
+	struct strbuf promisor_name = STRBUF_INIT;
+	int suffix_stripped;
+	FILE *output;
+	int i;
+
+	strbuf_addstr(&promisor_name, keep_name);
+	suffix_stripped = strbuf_strip_suffix(&promisor_name, ".keep");
+	if (!suffix_stripped)
+		BUG("name of pack lockfile should end with .keep (was '%s')",
+		    keep_name);
+	strbuf_addstr(&promisor_name, ".promisor");
+
+	output = xfopen(promisor_name.buf, "w");
+	for (i = 0; i < nr_sought; i++)
+		fprintf(output, "%s %s\n", oid_to_hex(&sought[i]->old_oid),
+			sought[i]->name);
+	fclose(output);
+
+	strbuf_release(&promisor_name);
+}
+
+/*
+ * Pass 1 as "only_packfile" if the pack received is the only pack in this
+ * fetch request (that is, if there were no packfile URIs provided).
+ */
 static int get_pack(struct fetch_pack_args *args,
-		    int xd[2], char **pack_lockfile)
+		    int xd[2], struct string_list *pack_lockfiles,
+		    int only_packfile,
+		    struct ref **sought, int nr_sought)
 {
 	struct async demux;
 	int do_keep = args->keep_pack;
@@ -789,56 +841,86 @@ static int get_pack(struct fetch_pack_args *args,
 	}
 
 	if (alternate_shallow_file) {
-		argv_array_push(&cmd.args, "--shallow-file");
-		argv_array_push(&cmd.args, alternate_shallow_file);
+		strvec_push(&cmd.args, "--shallow-file");
+		strvec_push(&cmd.args, alternate_shallow_file);
 	}
 
-	if (do_keep) {
-		if (pack_lockfile)
+	if (do_keep || args->from_promisor) {
+		if (pack_lockfiles)
 			cmd.out = -1;
 		cmd_name = "index-pack";
-		argv_array_push(&cmd.args, cmd_name);
-		argv_array_push(&cmd.args, "--stdin");
+		strvec_push(&cmd.args, cmd_name);
+		strvec_push(&cmd.args, "--stdin");
 		if (!args->quiet && !args->no_progress)
-			argv_array_push(&cmd.args, "-v");
+			strvec_push(&cmd.args, "-v");
 		if (args->use_thin_pack)
-			argv_array_push(&cmd.args, "--fix-thin");
-		if (args->lock_pack || unpack_limit) {
+			strvec_push(&cmd.args, "--fix-thin");
+		if (do_keep && (args->lock_pack || unpack_limit)) {
 			char hostname[HOST_NAME_MAX + 1];
 			if (xgethostname(hostname, sizeof(hostname)))
 				xsnprintf(hostname, sizeof(hostname), "localhost");
-			argv_array_pushf(&cmd.args,
-					"--keep=fetch-pack %"PRIuMAX " on %s",
-					(uintmax_t)getpid(), hostname);
+			strvec_pushf(&cmd.args,
+				     "--keep=fetch-pack %"PRIuMAX " on %s",
+				     (uintmax_t)getpid(), hostname);
 		}
-		if (args->check_self_contained_and_connected)
-			argv_array_push(&cmd.args, "--check-self-contained-and-connected");
+		if (only_packfile && args->check_self_contained_and_connected)
+			strvec_push(&cmd.args, "--check-self-contained-and-connected");
+		else
+			/*
+			 * We cannot perform any connectivity checks because
+			 * not all packs have been downloaded; let the caller
+			 * have this responsibility.
+			 */
+			args->check_self_contained_and_connected = 0;
+
+		if (args->from_promisor)
+			/*
+			 * write_promisor_file() may be called afterwards but
+			 * we still need index-pack to know that this is a
+			 * promisor pack. For example, if transfer.fsckobjects
+			 * is true, index-pack needs to know that .gitmodules
+			 * is a promisor object (so that it won't complain if
+			 * it is missing).
+			 */
+			strvec_push(&cmd.args, "--promisor");
 	}
 	else {
 		cmd_name = "unpack-objects";
-		argv_array_push(&cmd.args, cmd_name);
+		strvec_push(&cmd.args, cmd_name);
 		if (args->quiet || args->no_progress)
-			argv_array_push(&cmd.args, "-q");
+			strvec_push(&cmd.args, "-q");
 		args->check_self_contained_and_connected = 0;
 	}
 
 	if (pass_header)
-		argv_array_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
-				 ntohl(header.hdr_version),
+		strvec_pushf(&cmd.args, "--pack_header=%"PRIu32",%"PRIu32,
+			     ntohl(header.hdr_version),
 				 ntohl(header.hdr_entries));
 	if (fetch_fsck_objects >= 0
 	    ? fetch_fsck_objects
 	    : transfer_fsck_objects >= 0
 	    ? transfer_fsck_objects
-	    : 0)
-		argv_array_push(&cmd.args, "--strict");
+	    : 0) {
+		if (args->from_promisor || !only_packfile)
+			/*
+			 * We cannot use --strict in index-pack because it
+			 * checks both broken objects and links, but we only
+			 * want to check for broken objects.
+			 */
+			strvec_push(&cmd.args, "--fsck-objects");
+		else
+			strvec_pushf(&cmd.args, "--strict%s",
+				     fsck_msg_types.buf);
+	}
 
 	cmd.in = demux.out;
 	cmd.git_cmd = 1;
 	if (start_command(&cmd))
 		die(_("fetch-pack: unable to fork off %s"), cmd_name);
-	if (do_keep && pack_lockfile) {
-		*pack_lockfile = index_pack_lockfile(cmd.out);
+	if (do_keep && pack_lockfiles) {
+		char *pack_lockfile = index_pack_lockfile(cmd.out);
+		if (pack_lockfile)
+			string_list_append_nodup(pack_lockfiles, pack_lockfile);
 		close(cmd.out);
 	}
 
@@ -855,6 +937,14 @@ static int get_pack(struct fetch_pack_args *args,
 		die(_("%s failed"), cmd_name);
 	if (use_sideband && finish_async(&demux))
 		die(_("error in sideband demultiplexer"));
+
+	/*
+	 * Now that index-pack has succeeded, write the promisor file using the
+	 * obtained .keep filename if necessary
+	 */
+	if (do_keep && pack_lockfiles && pack_lockfiles->nr && args->from_promisor)
+		write_promisor_file(pack_lockfiles->items[0].string, sought, nr_sought);
+
 	return 0;
 }
 
@@ -870,82 +960,115 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 				 const struct ref *orig_ref,
 				 struct ref **sought, int nr_sought,
 				 struct shallow_info *si,
-				 char **pack_lockfile)
+				 struct string_list *pack_lockfiles)
 {
+	struct repository *r = the_repository;
 	struct ref *ref = copy_ref_list(orig_ref);
-	unsigned char sha1[20];
+	struct object_id oid;
 	const char *agent_feature;
 	int agent_len;
+	struct fetch_negotiator negotiator_alloc;
+	struct fetch_negotiator *negotiator;
+
+	negotiator = &negotiator_alloc;
+	fetch_negotiator_init(r, negotiator);
 
 	sort_ref_list(&ref, ref_compare_name);
 	QSORT(sought, nr_sought, cmp_ref_by_name);
 
-	if ((args->depth > 0 || is_repository_shallow()) && !server_supports("shallow"))
+	if ((agent_feature = server_feature_value("agent", &agent_len))) {
+		agent_supported = 1;
+		if (agent_len)
+			print_verbose(args, _("Server version is %.*s"),
+				      agent_len, agent_feature);
+	}
+
+	if (!server_supports("session-id"))
+		advertise_sid = 0;
+
+	if (server_supports("shallow"))
+		print_verbose(args, _("Server supports %s"), "shallow");
+	else if (args->depth > 0 || is_repository_shallow(r))
 		die(_("Server does not support shallow clients"));
 	if (args->depth > 0 || args->deepen_since || args->deepen_not)
 		args->deepen = 1;
 	if (server_supports("multi_ack_detailed")) {
-		print_verbose(args, _("Server supports multi_ack_detailed"));
+		print_verbose(args, _("Server supports %s"), "multi_ack_detailed");
 		multi_ack = 2;
 		if (server_supports("no-done")) {
-			print_verbose(args, _("Server supports no-done"));
+			print_verbose(args, _("Server supports %s"), "no-done");
 			if (args->stateless_rpc)
 				no_done = 1;
 		}
 	}
 	else if (server_supports("multi_ack")) {
-		print_verbose(args, _("Server supports multi_ack"));
+		print_verbose(args, _("Server supports %s"), "multi_ack");
 		multi_ack = 1;
 	}
 	if (server_supports("side-band-64k")) {
-		print_verbose(args, _("Server supports side-band-64k"));
+		print_verbose(args, _("Server supports %s"), "side-band-64k");
 		use_sideband = 2;
 	}
 	else if (server_supports("side-band")) {
-		print_verbose(args, _("Server supports side-band"));
+		print_verbose(args, _("Server supports %s"), "side-band");
 		use_sideband = 1;
 	}
 	if (server_supports("allow-tip-sha1-in-want")) {
-		print_verbose(args, _("Server supports allow-tip-sha1-in-want"));
+		print_verbose(args, _("Server supports %s"), "allow-tip-sha1-in-want");
 		allow_unadvertised_object_request |= ALLOW_TIP_SHA1;
 	}
 	if (server_supports("allow-reachable-sha1-in-want")) {
-		print_verbose(args, _("Server supports allow-reachable-sha1-in-want"));
+		print_verbose(args, _("Server supports %s"), "allow-reachable-sha1-in-want");
 		allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
 	}
-	if (!server_supports("thin-pack"))
+	if (server_supports("thin-pack"))
+		print_verbose(args, _("Server supports %s"), "thin-pack");
+	else
 		args->use_thin_pack = 0;
-	if (!server_supports("no-progress"))
+	if (server_supports("no-progress"))
+		print_verbose(args, _("Server supports %s"), "no-progress");
+	else
 		args->no_progress = 0;
-	if (!server_supports("include-tag"))
+	if (server_supports("include-tag"))
+		print_verbose(args, _("Server supports %s"), "include-tag");
+	else
 		args->include_tag = 0;
 	if (server_supports("ofs-delta"))
-		print_verbose(args, _("Server supports ofs-delta"));
+		print_verbose(args, _("Server supports %s"), "ofs-delta");
 	else
 		prefer_ofs_delta = 0;
 
-	if ((agent_feature = server_feature_value("agent", &agent_len))) {
-		agent_supported = 1;
-		if (agent_len)
-			print_verbose(args, _("Server version is %.*s"),
-				      agent_len, agent_feature);
+	if (server_supports("filter")) {
+		server_supports_filtering = 1;
+		print_verbose(args, _("Server supports %s"), "filter");
+	} else if (args->filter_options.choice) {
+		warning("filtering not recognized by server, ignoring");
 	}
-	if (server_supports("deepen-since"))
+
+	if (server_supports("deepen-since")) {
+		print_verbose(args, _("Server supports %s"), "deepen-since");
 		deepen_since_ok = 1;
-	else if (args->deepen_since)
+	} else if (args->deepen_since)
 		die(_("Server does not support --shallow-since"));
-	if (server_supports("deepen-not"))
+	if (server_supports("deepen-not")) {
+		print_verbose(args, _("Server supports %s"), "deepen-not");
 		deepen_not_ok = 1;
-	else if (args->deepen_not)
+	} else if (args->deepen_not)
 		die(_("Server does not support --shallow-exclude"));
-	if (!server_supports("deepen-relative") && args->deepen_relative)
+	if (server_supports("deepen-relative"))
+		print_verbose(args, _("Server supports %s"), "deepen-relative");
+	else if (args->deepen_relative)
 		die(_("Server does not support --deepen"));
+	if (!server_supports_hash(the_hash_algo->name, NULL))
+		die(_("Server does not support this repository's object format"));
 
-	if (everything_local(args, &ref, sought, nr_sought)) {
+	mark_complete_and_common_ref(negotiator, args, &ref);
+	filter_refs(args, &ref, sought, nr_sought);
+	if (everything_local(args, &ref)) {
 		packet_flush(fd[1]);
 		goto all_done;
 	}
-	if (find_common(args, fd, sha1, ref) < 0)
+	if (find_common(negotiator, args, fd, &oid, ref) < 0)
 		if (!args->keep_pack)
 			/* When cloning, it is not unusual to have
 			 * no common commit.
@@ -961,13 +1084,635 @@ static struct ref *do_fetch_pack(struct fetch_pack_args *args,
 		alternate_shallow_file = setup_temporary_shallow(si->shallow);
 	else
 		alternate_shallow_file = NULL;
-	if (get_pack(args, fd, pack_lockfile))
+	if (get_pack(args, fd, pack_lockfiles, 1, sought, nr_sought))
 		die(_("git fetch-pack: fetch failed."));
 
  all_done:
+	if (negotiator)
+		negotiator->release(negotiator);
+	return ref;
+}
+
+static void add_shallow_requests(struct strbuf *req_buf,
+				 const struct fetch_pack_args *args)
+{
+	if (is_repository_shallow(the_repository))
+		write_shallow_commits(req_buf, 1, NULL);
+	if (args->depth > 0)
+		packet_buf_write(req_buf, "deepen %d", args->depth);
+	if (args->deepen_since) {
+		timestamp_t max_age = approxidate(args->deepen_since);
+		packet_buf_write(req_buf, "deepen-since %"PRItime, max_age);
+	}
+	if (args->deepen_not) {
+		int i;
+		for (i = 0; i < args->deepen_not->nr; i++) {
+			struct string_list_item *s = args->deepen_not->items + i;
+			packet_buf_write(req_buf, "deepen-not %s", s->string);
+		}
+	}
+	if (args->deepen_relative)
+		packet_buf_write(req_buf, "deepen-relative\n");
+}
+
+static void add_wants(const struct ref *wants, struct strbuf *req_buf)
+{
+	int use_ref_in_want = server_supports_feature("fetch", "ref-in-want", 0);
+
+	for ( ; wants ; wants = wants->next) {
+		const struct object_id *remote = &wants->old_oid;
+		struct object *o;
+
+		/*
+		 * If that object is complete (i.e. it is an ancestor of a
+		 * local ref), we tell them we have it but do not have to
+		 * tell them about its ancestors, which they already know
+		 * about.
+		 *
+		 * We use lookup_object here because we are only
+		 * interested in the case we *know* the object is
+		 * reachable and we have already scanned it.
+		 */
+		if (((o = lookup_object(the_repository, remote)) != NULL) &&
+		    (o->flags & COMPLETE)) {
+			continue;
+		}
+
+		if (!use_ref_in_want || wants->exact_oid)
+			packet_buf_write(req_buf, "want %s\n", oid_to_hex(remote));
+		else
+			packet_buf_write(req_buf, "want-ref %s\n", wants->name);
+	}
+}
+
+static void add_common(struct strbuf *req_buf, struct oidset *common)
+{
+	struct oidset_iter iter;
+	const struct object_id *oid;
+	oidset_iter_init(common, &iter);
+
+	while ((oid = oidset_iter_next(&iter))) {
+		packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
+	}
+}
+
+static int add_haves(struct fetch_negotiator *negotiator,
+		     int seen_ack,
+		     struct strbuf *req_buf,
+		     int *haves_to_send, int *in_vain)
+{
+	int ret = 0;
+	int haves_added = 0;
+	const struct object_id *oid;
+
+	while ((oid = negotiator->next(negotiator))) {
+		packet_buf_write(req_buf, "have %s\n", oid_to_hex(oid));
+		if (++haves_added >= *haves_to_send)
+			break;
+	}
+
+	*in_vain += haves_added;
+	if (!haves_added || (seen_ack && *in_vain >= MAX_IN_VAIN)) {
+		/* Send Done */
+		packet_buf_write(req_buf, "done\n");
+		ret = 1;
+	}
+
+	/* Increase haves to send on next round */
+	*haves_to_send = next_flush(1, *haves_to_send);
+
+	return ret;
+}
+
+static int send_fetch_request(struct fetch_negotiator *negotiator, int fd_out,
+			      struct fetch_pack_args *args,
+			      const struct ref *wants, struct oidset *common,
+			      int *haves_to_send, int *in_vain,
+			      int sideband_all, int seen_ack)
+{
+	int ret = 0;
+	const char *hash_name;
+	struct strbuf req_buf = STRBUF_INIT;
+
+	if (server_supports_v2("fetch", 1))
+		packet_buf_write(&req_buf, "command=fetch");
+	if (server_supports_v2("agent", 0))
+		packet_buf_write(&req_buf, "agent=%s", git_user_agent_sanitized());
+	if (advertise_sid && server_supports_v2("session-id", 0))
+		packet_buf_write(&req_buf, "session-id=%s", trace2_session_id());
+	if (args->server_options && args->server_options->nr &&
+	    server_supports_v2("server-option", 1)) {
+		int i;
+		for (i = 0; i < args->server_options->nr; i++)
+			packet_buf_write(&req_buf, "server-option=%s",
+					 args->server_options->items[i].string);
+	}
+
+	if (server_feature_v2("object-format", &hash_name)) {
+		int hash_algo = hash_algo_by_name(hash_name);
+		if (hash_algo_by_ptr(the_hash_algo) != hash_algo)
+			die(_("mismatched algorithms: client %s; server %s"),
+			    the_hash_algo->name, hash_name);
+		packet_write_fmt(fd_out, "object-format=%s", the_hash_algo->name);
+	} else if (hash_algo_by_ptr(the_hash_algo) != GIT_HASH_SHA1) {
+		die(_("the server does not support algorithm '%s'"),
+		    the_hash_algo->name);
+	}
+
+	packet_buf_delim(&req_buf);
+	if (args->use_thin_pack)
+		packet_buf_write(&req_buf, "thin-pack");
+	if (args->no_progress)
+		packet_buf_write(&req_buf, "no-progress");
+	if (args->include_tag)
+		packet_buf_write(&req_buf, "include-tag");
+	if (prefer_ofs_delta)
+		packet_buf_write(&req_buf, "ofs-delta");
+	if (sideband_all)
+		packet_buf_write(&req_buf, "sideband-all");
+
+	/* Add shallow-info and deepen request */
+	if (server_supports_feature("fetch", "shallow", 0))
+		add_shallow_requests(&req_buf, args);
+	else if (is_repository_shallow(the_repository) || args->deepen)
+		die(_("Server does not support shallow requests"));
+
+	/* Add filter */
+	if (server_supports_feature("fetch", "filter", 0) &&
+	    args->filter_options.choice) {
+		const char *spec =
+			expand_list_objects_filter_spec(&args->filter_options);
+		print_verbose(args, _("Server supports filter"));
+		packet_buf_write(&req_buf, "filter %s", spec);
+	} else if (args->filter_options.choice) {
+		warning("filtering not recognized by server, ignoring");
+	}
+
+	if (server_supports_feature("fetch", "packfile-uris", 0)) {
+		int i;
+		struct strbuf to_send = STRBUF_INIT;
+
+		for (i = 0; i < uri_protocols.nr; i++) {
+			const char *s = uri_protocols.items[i].string;
+
+			if (!strcmp(s, "https") || !strcmp(s, "http")) {
+				if (to_send.len)
+					strbuf_addch(&to_send, ',');
+				strbuf_addstr(&to_send, s);
+			}
+		}
+		if (to_send.len) {
+			packet_buf_write(&req_buf, "packfile-uris %s",
+					 to_send.buf);
+			strbuf_release(&to_send);
+		}
+	}
+
+	/* add wants */
+	add_wants(wants, &req_buf);
+
+	/* Add all of the common commits we've found in previous rounds */
+	add_common(&req_buf, common);
+
+	/* Add initial haves */
+	ret = add_haves(negotiator, seen_ack, &req_buf,
+			haves_to_send, in_vain);
+
+	/* Send request */
+	packet_buf_flush(&req_buf);
+	if (write_in_full(fd_out, req_buf.buf, req_buf.len) < 0)
+		die_errno(_("unable to write request to remote"));
+
+	strbuf_release(&req_buf);
+	return ret;
+}
+
+/*
+ * Processes a section header in a server's response and checks if it matches
+ * `section`.  If the value of `peek` is 1, the header line will be peeked (and
+ * not consumed); if 0, the line will be consumed and the function will die if
+ * the section header doesn't match what was expected.
+ */
+static int process_section_header(struct packet_reader *reader,
+				  const char *section, int peek)
+{
+	int ret;
+
+	if (packet_reader_peek(reader) != PACKET_READ_NORMAL)
+		die(_("error reading section header '%s'"), section);
+
+	ret = !strcmp(reader->line, section);
+
+	if (!peek) {
+		if (!ret)
+			die(_("expected '%s', received '%s'"),
+			    section, reader->line);
+		packet_reader_read(reader);
+	}
+
+	return ret;
+}
+
+enum common_found {
+	/*
+	 * No commit was found to be possessed by both the client and the
+	 * server, and "ready" was not received.
+	 */
+	NO_COMMON_FOUND,
+
+	/*
+	 * At least one commit was found to be possessed by both the client and
+	 * the server, and "ready" was not received.
+	 */
+	COMMON_FOUND,
+
+	/*
+	 * "ready" was received, indicating that the server is ready to send
+	 * the packfile without any further negotiation.
+	 */
+	READY
+};
+
+static enum common_found process_acks(struct fetch_negotiator *negotiator,
+				      struct packet_reader *reader,
+				      struct oidset *common)
+{
+	/* received */
+	int received_ready = 0;
+	int received_ack = 0;
+
+	process_section_header(reader, "acknowledgments", 0);
+	while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
+		const char *arg;
+
+		if (!strcmp(reader->line, "NAK"))
+			continue;
+
+		if (skip_prefix(reader->line, "ACK ", &arg)) {
+			struct object_id oid;
+			received_ack = 1;
+			if (!get_oid_hex(arg, &oid)) {
+				struct commit *commit;
+				oidset_insert(common, &oid);
+				commit = lookup_commit(the_repository, &oid);
+				if (negotiator)
+					negotiator->ack(negotiator, commit);
+			}
+			continue;
+		}
+
+		if (!strcmp(reader->line, "ready")) {
+			received_ready = 1;
+			continue;
+		}
+
+		die(_("unexpected acknowledgment line: '%s'"), reader->line);
+	}
+
+	if (reader->status != PACKET_READ_FLUSH &&
+	    reader->status != PACKET_READ_DELIM)
+		die(_("error processing acks: %d"), reader->status);
+
+	/*
+	 * If an "acknowledgments" section is sent, a packfile is sent if and
+	 * only if "ready" was sent in this section. The other sections
+	 * ("shallow-info" and "wanted-refs") are sent only if a packfile is
+	 * sent. Therefore, a DELIM is expected if "ready" is sent, and a FLUSH
+	 * otherwise.
+	 */
+	if (received_ready && reader->status != PACKET_READ_DELIM)
+		die(_("expected packfile to be sent after 'ready'"));
+	if (!received_ready && reader->status != PACKET_READ_FLUSH)
+		die(_("expected no other sections to be sent after no 'ready'"));
+
+	return received_ready ? READY :
+		(received_ack ? COMMON_FOUND : NO_COMMON_FOUND);
+}
+
+static void receive_shallow_info(struct fetch_pack_args *args,
+				 struct packet_reader *reader,
+				 struct oid_array *shallows,
+				 struct shallow_info *si)
+{
+	int unshallow_received = 0;
+
+	process_section_header(reader, "shallow-info", 0);
+	while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
+		const char *arg;
+		struct object_id oid;
+
+		if (skip_prefix(reader->line, "shallow ", &arg)) {
+			if (get_oid_hex(arg, &oid))
+				die(_("invalid shallow line: %s"), reader->line);
+			oid_array_append(shallows, &oid);
+			continue;
+		}
+		if (skip_prefix(reader->line, "unshallow ", &arg)) {
+			if (get_oid_hex(arg, &oid))
+				die(_("invalid unshallow line: %s"), reader->line);
+			if (!lookup_object(the_repository, &oid))
+				die(_("object not found: %s"), reader->line);
+			/* make sure that it is parsed as shallow */
+			if (!parse_object(the_repository, &oid))
+				die(_("error in object: %s"), reader->line);
+			if (unregister_shallow(&oid))
+				die(_("no shallow found: %s"), reader->line);
+			unshallow_received = 1;
+			continue;
+		}
+		die(_("expected shallow/unshallow, got %s"), reader->line);
+	}
+
+	if (reader->status != PACKET_READ_FLUSH &&
+	    reader->status != PACKET_READ_DELIM)
+		die(_("error processing shallow info: %d"), reader->status);
+
+	if (args->deepen || unshallow_received) {
+		/*
+		 * Treat these as shallow lines caused by our depth settings.
+		 * In v0, these lines cannot cause refs to be rejected; do the
+		 * same.
+		 */
+		int i;
+
+		for (i = 0; i < shallows->nr; i++)
+			register_shallow(the_repository, &shallows->oid[i]);
+		setup_alternate_shallow(&shallow_lock, &alternate_shallow_file,
+					NULL);
+		args->deepen = 1;
+	} else if (shallows->nr) {
+		/*
+		 * Treat these as shallow lines caused by the remote being
+		 * shallow. In v0, remote refs that reach these objects are
+		 * rejected (unless --update-shallow is set); do the same.
+		 */
+		prepare_shallow_info(si, shallows);
+		if (si->nr_ours || si->nr_theirs)
+			alternate_shallow_file =
+				setup_temporary_shallow(si->shallow);
+		else
+			alternate_shallow_file = NULL;
+	} else {
+		alternate_shallow_file = NULL;
+	}
+}
+
+static int cmp_name_ref(const void *name, const void *ref)
+{
+	return strcmp(name, (*(struct ref **)ref)->name);
+}
+
+static void receive_wanted_refs(struct packet_reader *reader,
+				struct ref **sought, int nr_sought)
+{
+	process_section_header(reader, "wanted-refs", 0);
+	while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
+		struct object_id oid;
+		const char *end;
+		struct ref **found;
+
+		if (parse_oid_hex(reader->line, &oid, &end) || *end++ != ' ')
+			die(_("expected wanted-ref, got '%s'"), reader->line);
+
+		found = bsearch(end, sought, nr_sought, sizeof(*sought),
+				cmp_name_ref);
+		if (!found)
+			die(_("unexpected wanted-ref: '%s'"), reader->line);
+		oidcpy(&(*found)->old_oid, &oid);
+	}
+
+	if (reader->status != PACKET_READ_DELIM)
+		die(_("error processing wanted refs: %d"), reader->status);
+}
+
+static void receive_packfile_uris(struct packet_reader *reader,
+				  struct string_list *uris)
+{
+	process_section_header(reader, "packfile-uris", 0);
+	while (packet_reader_read(reader) == PACKET_READ_NORMAL) {
+		if (reader->pktlen < the_hash_algo->hexsz ||
+		    reader->line[the_hash_algo->hexsz] != ' ')
+			die("expected '<hash> <uri>', got: %s\n", reader->line);
+
+		string_list_append(uris, reader->line);
+	}
+	if (reader->status != PACKET_READ_DELIM)
+		die("expected DELIM");
+}
+
+enum fetch_state {
+	FETCH_CHECK_LOCAL = 0,
+	FETCH_SEND_REQUEST,
+	FETCH_PROCESS_ACKS,
+	FETCH_GET_PACK,
+	FETCH_DONE,
+};
+
+static void do_check_stateless_delimiter(const struct fetch_pack_args *args,
+					 struct packet_reader *reader)
+{
+	check_stateless_delimiter(args->stateless_rpc, reader,
+				  _("git fetch-pack: expected response end packet"));
+}
+
+static struct ref *do_fetch_pack_v2(struct fetch_pack_args *args,
+				    int fd[2],
+				    const struct ref *orig_ref,
+				    struct ref **sought, int nr_sought,
+				    struct oid_array *shallows,
+				    struct shallow_info *si,
+				    struct string_list *pack_lockfiles)
+{
+	struct repository *r = the_repository;
+	struct ref *ref = copy_ref_list(orig_ref);
+	enum fetch_state state = FETCH_CHECK_LOCAL;
+	struct oidset common = OIDSET_INIT;
+	struct packet_reader reader;
+	int in_vain = 0, negotiation_started = 0;
+	int haves_to_send = INITIAL_FLUSH;
+	struct fetch_negotiator negotiator_alloc;
+	struct fetch_negotiator *negotiator;
+	int seen_ack = 0;
+	struct string_list packfile_uris = STRING_LIST_INIT_DUP;
+	int i;
+
+	negotiator = &negotiator_alloc;
+	fetch_negotiator_init(r, negotiator);
+
+	packet_reader_init(&reader, fd[0], NULL, 0,
+			   PACKET_READ_CHOMP_NEWLINE |
+			   PACKET_READ_DIE_ON_ERR_PACKET);
+	if (git_env_bool("GIT_TEST_SIDEBAND_ALL", 1) &&
+	    server_supports_feature("fetch", "sideband-all", 0)) {
+		reader.use_sideband = 1;
+		reader.me = "fetch-pack";
+	}
+
+	while (state != FETCH_DONE) {
+		switch (state) {
+		case FETCH_CHECK_LOCAL:
+			sort_ref_list(&ref, ref_compare_name);
+			QSORT(sought, nr_sought, cmp_ref_by_name);
+
+			/* v2 supports these by default */
+			allow_unadvertised_object_request |= ALLOW_REACHABLE_SHA1;
+			use_sideband = 2;
+			if (args->depth > 0 || args->deepen_since || args->deepen_not)
+				args->deepen = 1;
+
+			/* Filter 'ref' by 'sought' and those that aren't local */
+			mark_complete_and_common_ref(negotiator, args, &ref);
+			filter_refs(args, &ref, sought, nr_sought);
+			if (everything_local(args, &ref))
+				state = FETCH_DONE;
+			else
+				state = FETCH_SEND_REQUEST;
+
+			mark_tips(negotiator, args->negotiation_tips);
+			for_each_cached_alternate(negotiator,
+						  insert_one_alternate_object);
+			break;
+		case FETCH_SEND_REQUEST:
+			if (!negotiation_started) {
+				negotiation_started = 1;
+				trace2_region_enter("fetch-pack",
+						    "negotiation_v2",
+						    the_repository);
+			}
+			if (send_fetch_request(negotiator, fd[1], args, ref,
+					       &common,
+					       &haves_to_send, &in_vain,
+					       reader.use_sideband,
+					       seen_ack))
+				state = FETCH_GET_PACK;
+			else
+				state = FETCH_PROCESS_ACKS;
+			break;
+		case FETCH_PROCESS_ACKS:
+			/* Process ACKs/NAKs */
+			switch (process_acks(negotiator, &reader, &common)) {
+			case READY:
+				/*
+				 * Don't check for response delimiter; get_pack() will
+				 * read the rest of this response.
+				 */
+				state = FETCH_GET_PACK;
+				break;
+			case COMMON_FOUND:
+				in_vain = 0;
+				seen_ack = 1;
+				/* fallthrough */
+			case NO_COMMON_FOUND:
+				do_check_stateless_delimiter(args, &reader);
+				state = FETCH_SEND_REQUEST;
+				break;
+			}
+			break;
+		case FETCH_GET_PACK:
+			trace2_region_leave("fetch-pack",
+					    "negotiation_v2",
+					    the_repository);
+			/* Check for shallow-info section */
+			if (process_section_header(&reader, "shallow-info", 1))
+				receive_shallow_info(args, &reader, shallows, si);
+
+			if (process_section_header(&reader, "wanted-refs", 1))
+				receive_wanted_refs(&reader, sought, nr_sought);
+
+			/* get the pack(s) */
+			if (process_section_header(&reader, "packfile-uris", 1))
+				receive_packfile_uris(&reader, &packfile_uris);
+			process_section_header(&reader, "packfile", 0);
+			if (get_pack(args, fd, pack_lockfiles,
+				     !packfile_uris.nr, sought, nr_sought))
+				die(_("git fetch-pack: fetch failed."));
+			do_check_stateless_delimiter(args, &reader);
+
+			state = FETCH_DONE;
+			break;
+		case FETCH_DONE:
+			continue;
+		}
+	}
+
+	for (i = 0; i < packfile_uris.nr; i++) {
+		struct child_process cmd = CHILD_PROCESS_INIT;
+		char packname[GIT_MAX_HEXSZ + 1];
+		const char *uri = packfile_uris.items[i].string +
+			the_hash_algo->hexsz + 1;
+
+		strvec_push(&cmd.args, "http-fetch");
+		strvec_pushf(&cmd.args, "--packfile=%.*s",
+			     (int) the_hash_algo->hexsz,
+			     packfile_uris.items[i].string);
+		strvec_push(&cmd.args, uri);
+		cmd.git_cmd = 1;
+		cmd.no_stdin = 1;
+		cmd.out = -1;
+		if (start_command(&cmd))
+			die("fetch-pack: unable to spawn http-fetch");
+
+		if (read_in_full(cmd.out, packname, 5) < 0 ||
+		    memcmp(packname, "keep\t", 5))
+			die("fetch-pack: expected keep then TAB at start of http-fetch output");
+
+		if (read_in_full(cmd.out, packname,
+				 the_hash_algo->hexsz + 1) < 0 ||
+		    packname[the_hash_algo->hexsz] != '\n')
+			die("fetch-pack: expected hash then LF at end of http-fetch output");
+
+		packname[the_hash_algo->hexsz] = '\0';
+
+		close(cmd.out);
+
+		if (finish_command(&cmd))
+			die("fetch-pack: unable to finish http-fetch");
+
+		if (memcmp(packfile_uris.items[i].string, packname,
+			   the_hash_algo->hexsz))
+			die("fetch-pack: pack downloaded from %s does not match expected hash %.*s",
+			    uri, (int) the_hash_algo->hexsz,
+			    packfile_uris.items[i].string);
+
+		string_list_append_nodup(pack_lockfiles,
+					 xstrfmt("%s/pack/pack-%s.keep",
+						 get_object_directory(),
+						 packname));
+	}
+	string_list_clear(&packfile_uris, 0);
+
+	if (negotiator)
+		negotiator->release(negotiator);
+
+	oidset_clear(&common);
 	return ref;
 }
 
+static int fetch_pack_config_cb(const char *var, const char *value, void *cb)
+{
+	if (strcmp(var, "fetch.fsck.skiplist") == 0) {
+		const char *path;
+
+		if (git_config_pathname(&path, var, value))
+			return 1;
+		strbuf_addf(&fsck_msg_types, "%cskiplist=%s",
+			fsck_msg_types.len ? ',' : '=', path);
+		free((char *)path);
+		return 0;
+	}
+
+	if (skip_prefix(var, "fetch.fsck.", &var)) {
+		if (is_valid_msg_type(var, value))
+			strbuf_addf(&fsck_msg_types, "%c%s=%s",
+				fsck_msg_types.len ? ',' : '=', var, value);
+		else
+			warning("Skipping unknown msg id '%s'", var);
+		return 0;
+	}
+
+	return git_default_config(var, value, cb);
+}
+
 static void fetch_pack_config(void)
 {
 	git_config_get_int("fetch.unpacklimit", &fetch_unpack_limit);
@@ -975,8 +1720,17 @@ static void fetch_pack_config(void)
 	git_config_get_bool("repack.usedeltabaseoffset", &prefer_ofs_delta);
 	git_config_get_bool("fetch.fsckobjects", &fetch_fsck_objects);
 	git_config_get_bool("transfer.fsckobjects", &transfer_fsck_objects);
+	git_config_get_bool("transfer.advertisesid", &advertise_sid);
+	if (!uri_protocols.nr) {
+		char *str;
 
-	git_config(git_default_config, NULL);
+		if (!git_config_get_string("fetch.uriprotocols", &str) && str) {
+			string_list_split(&uri_protocols, str, ',', -1);
+			free(str);
+		}
+	}
+
+	git_config(fetch_pack_config_cb, NULL);
 }
 
 static void fetch_pack_setup(void)
@@ -1023,10 +1777,11 @@ static void update_shallow(struct fetch_pack_args *args,
 
 	if (args->deepen && alternate_shallow_file) {
 		if (*alternate_shallow_file == '\0') { /* --unshallow */
-			unlink_or_warn(git_path_shallow());
-			rollback_lock_file(&shallow_lock);
+			unlink_or_warn(git_path_shallow(the_repository));
+			rollback_shallow_file(the_repository, &shallow_lock);
 		} else
-			commit_lock_file(&shallow_lock);
+			commit_shallow_file(the_repository, &shallow_lock);
+		alternate_shallow_file = NULL;
 		return;
 	}
 
@@ -1049,7 +1804,8 @@ static void update_shallow(struct fetch_pack_args *args,
 			setup_alternate_shallow(&shallow_lock,
 						&alternate_shallow_file,
 						&extra);
-			commit_lock_file(&shallow_lock);
+			commit_shallow_file(the_repository, &shallow_lock);
+			alternate_shallow_file = NULL;
 		}
 		oid_array_clear(&extra);
 		return;
@@ -1086,9 +1842,10 @@ static void update_shallow(struct fetch_pack_args *args,
 		setup_alternate_shallow(&shallow_lock,
 					&alternate_shallow_file,
 					&extra);
-		commit_lock_file(&shallow_lock);
+		commit_shallow_file(the_repository, &shallow_lock);
 		oid_array_clear(&extra);
 		oid_array_clear(&ref);
+		alternate_shallow_file = NULL;
 		return;
 	}
 
@@ -1107,31 +1864,72 @@ static void update_shallow(struct fetch_pack_args *args,
 	oid_array_clear(&ref);
 }
 
+static int iterate_ref_map(void *cb_data, struct object_id *oid)
+{
+	struct ref **rm = cb_data;
+	struct ref *ref = *rm;
+
+	if (!ref)
+		return -1; /* end of the list */
+	*rm = ref->next;
+	oidcpy(oid, &ref->old_oid);
+	return 0;
+}
+
 struct ref *fetch_pack(struct fetch_pack_args *args,
-		       int fd[], struct child_process *conn,
+		       int fd[],
 		       const struct ref *ref,
-		       const char *dest,
 		       struct ref **sought, int nr_sought,
 		       struct oid_array *shallow,
-		       char **pack_lockfile)
+		       struct string_list *pack_lockfiles,
+		       enum protocol_version version)
 {
 	struct ref *ref_cpy;
 	struct shallow_info si;
+	struct oid_array shallows_scratch = OID_ARRAY_INIT;
 
 	fetch_pack_setup();
 	if (nr_sought)
 		nr_sought = remove_duplicates_in_refs(sought, nr_sought);
 
-	if (!ref) {
+	if (version != protocol_v2 && !ref) {
 		packet_flush(fd[1]);
 		die(_("no matching remote head"));
 	}
-	prepare_shallow_info(&si, shallow);
-	ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
-				&si, pack_lockfile);
-	reprepare_packed_git();
+	if (version == protocol_v2) {
+		if (shallow->nr)
+			BUG("Protocol V2 does not provide shallows at this point in the fetch");
+		memset(&si, 0, sizeof(si));
+		ref_cpy = do_fetch_pack_v2(args, fd, ref, sought, nr_sought,
+					   &shallows_scratch, &si,
+					   pack_lockfiles);
+	} else {
+		prepare_shallow_info(&si, shallow);
+		ref_cpy = do_fetch_pack(args, fd, ref, sought, nr_sought,
+					&si, pack_lockfiles);
+	}
+	reprepare_packed_git(the_repository);
+
+	if (!args->cloning && args->deepen) {
+		struct check_connected_options opt = CHECK_CONNECTED_INIT;
+		struct ref *iterator = ref_cpy;
+		opt.shallow_file = alternate_shallow_file;
+		if (args->deepen)
+			opt.is_deepening_fetch = 1;
+		if (check_connected(iterate_ref_map, &iterator, &opt)) {
+			error(_("remote did not send all necessary objects"));
+			free_refs(ref_cpy);
+			ref_cpy = NULL;
+			rollback_shallow_file(the_repository, &shallow_lock);
+			goto cleanup;
+		}
+		args->connectivity_checked = 1;
+	}
+
 	update_shallow(args, sought, nr_sought, &si);
+cleanup:
 	clear_shallow_info(&si);
+	oid_array_clear(&shallows_scratch);
 	return ref_cpy;
 }