Merge remote-tracking branch 'ko/maint' into jc/diff-index-quick-exit-early

* ko/maint: (4352 commits)
  git-submodule.sh: separate parens by a space to avoid confusing some shells
  Documentation/technical/api-diff.txt: correct name of diff_unmerge()
  read_gitfile_gently: use ssize_t to hold read result
  remove tests of always-false condition
  rerere.c: diagnose a corrupt MERGE_RR when hitting EOF between TAB and '\0'
  Git 1.7.5.3
  init/clone: remove short option -L and document --separate-git-dir
  do not read beyond end of malloc'd buffer
  git-svn: Fix git svn log --show-commit
  Git 1.7.5.2
  provide a copy of the LGPLv2.1
  test core.gitproxy configuration
  copy_gecos: fix not adding nlen to len when processing "&"
  Update draft release notes to 1.7.5.2
  Documentation/git-fsck.txt: fix typo: unreadable -> unreachable
  send-pack: avoid deadlock on git:// push with failed pack-objects
  connect: let callers know if connection is a socket
  connect: treat generic proxy processes like ssh processes
  sideband_demux(): fix decl-after-stmt
  t3503: test cherry picking and reverting root commits
  ...

Conflicts:
	diff.c

1 files changed, 1021 insertions, 0 deletions

diff --git a/builtin/fetch-pack.c b/builtin/fetch-pack.c
new file mode 100644
index 0000000000..85aff029b2
--- /dev/null
+++ b/builtin/fetch-pack.c
@@ -0,0 +1,1021 @@
+#include "builtin.h"
+#include "refs.h"
+#include "pkt-line.h"
+#include "commit.h"
+#include "tag.h"
+#include "exec_cmd.h"
+#include "pack.h"
+#include "sideband.h"
+#include "fetch-pack.h"
+#include "remote.h"
+#include "run-command.h"
+#include "transport.h"
+
+static int transfer_unpack_limit = -1;
+static int fetch_unpack_limit = -1;
+static int unpack_limit = 100;
+static int prefer_ofs_delta = 1;
+static int no_done = 0;
+static struct fetch_pack_args args = {
+	/* .uploadpack = */ "git-upload-pack",
+};
+
+static const char fetch_pack_usage[] =
+"git fetch-pack [--all] [--quiet|-q] [--keep|-k] [--thin] [--include-tag] [--upload-pack=<git-upload-pack>] [--depth=<n>] [--no-progress] [-v] [<host>:]<directory> [<refs>...]";
+
+#define COMPLETE	(1U << 0)
+#define COMMON		(1U << 1)
+#define COMMON_REF	(1U << 2)
+#define SEEN		(1U << 3)
+#define POPPED		(1U << 4)
+
+static int marked;
+
+/*
+ * After sending this many "have"s if we do not get any new ACK , we
+ * give up traversing our history.
+ */
+#define MAX_IN_VAIN 256
+
+static struct commit_list *rev_list;
+static int non_common_revs, multi_ack, use_sideband;
+
+static void rev_list_push(struct commit *commit, int mark)
+{
+	if (!(commit->object.flags & mark)) {
+		commit->object.flags |= mark;
+
+		if (!(commit->object.parsed))
+			if (parse_commit(commit))
+				return;
+
+		commit_list_insert_by_date(commit, &rev_list);
+
+		if (!(commit->object.flags & COMMON))
+			non_common_revs++;
+	}
+}
+
+static int rev_list_insert_ref(const char *path, const unsigned char *sha1, int flag, void *cb_data)
+{
+	struct object *o = deref_tag(parse_object(sha1), path, 0);
+
+	if (o && o->type == OBJ_COMMIT)
+		rev_list_push((struct commit *)o, SEEN);
+
+	return 0;
+}
+
+static int clear_marks(const char *path, const unsigned char *sha1, int flag, void *cb_data)
+{
+	struct object *o = deref_tag(parse_object(sha1), path, 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 == NULL || non_common_revs == 0)
+			return NULL;
+
+		commit = rev_list->item;
+		if (!commit->object.parsed)
+			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;
+		}
+
+		rev_list = rev_list->next;
+	}
+
+	return commit->object.sha1;
+}
+
+enum ack_type {
+	NAK = 0,
+	ACK,
+	ACK_continue,
+	ACK_common,
+	ACK_ready
+};
+
+static void consume_shallow_list(int fd)
+{
+	if (args.stateless_rpc && args.depth > 0) {
+		/* 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[1000];
+		while (packet_read_line(fd, line, sizeof(line))) {
+			if (!prefixcmp(line, "shallow "))
+				continue;
+			if (!prefixcmp(line, "unshallow "))
+				continue;
+			die("git fetch-pack: expected shallow list");
+		}
+	}
+}
+
+static enum ack_type get_ack(int fd, unsigned char *result_sha1)
+{
+	static char line[1000];
+	int len = packet_read_line(fd, line, sizeof(line));
+
+	if (!len)
+		die("git fetch-pack: expected ACK/NAK, got EOF");
+	if (line[len-1] == '\n')
+		line[--len] = 0;
+	if (!strcmp(line, "NAK"))
+		return NAK;
+	if (!prefixcmp(line, "ACK ")) {
+		if (!get_sha1_hex(line+4, result_sha1)) {
+			if (strstr(line+45, "continue"))
+				return ACK_continue;
+			if (strstr(line+45, "common"))
+				return ACK_common;
+			if (strstr(line+45, "ready"))
+				return ACK_ready;
+			return ACK;
+		}
+	}
+	die("git fetch_pack: expected ACK/NAK, got '%s'", line);
+}
+
+static void send_request(int fd, struct strbuf *buf)
+{
+	if (args.stateless_rpc) {
+		send_sideband(fd, -1, buf->buf, buf->len, LARGE_PACKET_MAX);
+		packet_flush(fd);
+	} else
+		safe_write(fd, buf->buf, buf->len);
+}
+
+static void insert_one_alternate_ref(const struct ref *ref, void *unused)
+{
+	rev_list_insert_ref(NULL, ref->old_sha1, 0, NULL);
+}
+
+static void insert_alternate_refs(void)
+{
+	foreach_alt_odb(refs_from_alternate_cb, insert_one_alternate_ref);
+}
+
+#define INITIAL_FLUSH 16
+#define PIPESAFE_FLUSH 32
+#define LARGE_FLUSH 1024
+
+static int next_flush(int count)
+{
+	int flush_limit = args.stateless_rpc ? LARGE_FLUSH : PIPESAFE_FLUSH;
+
+	if (count < flush_limit)
+		count <<= 1;
+	else
+		count += flush_limit;
+	return count;
+}
+
+static int find_common(int fd[2], unsigned char *result_sha1,
+		       struct ref *refs)
+{
+	int fetching;
+	int count = 0, flushes = 0, flush_at = INITIAL_FLUSH, retval;
+	const unsigned char *sha1;
+	unsigned in_vain = 0;
+	int got_continue = 0;
+	int got_ready = 0;
+	struct strbuf req_buf = STRBUF_INIT;
+	size_t state_len = 0;
+
+	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, NULL);
+	insert_alternate_refs();
+
+	fetching = 0;
+	for ( ; refs ; refs = refs->next) {
+		unsigned char *remote = refs->old_sha1;
+		const char *remote_hex;
+		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(remote)) != NULL) &&
+				(o->flags & COMPLETE)) {
+			continue;
+		}
+
+		remote_hex = sha1_to_hex(remote);
+		if (!fetching) {
+			struct strbuf c = STRBUF_INIT;
+			if (multi_ack == 2)     strbuf_addstr(&c, " multi_ack_detailed");
+			if (multi_ack == 1)     strbuf_addstr(&c, " multi_ack");
+			if (no_done)            strbuf_addstr(&c, " no-done");
+			if (use_sideband == 2)  strbuf_addstr(&c, " side-band-64k");
+			if (use_sideband == 1)  strbuf_addstr(&c, " side-band");
+			if (args.use_thin_pack) strbuf_addstr(&c, " thin-pack");
+			if (args.no_progress)   strbuf_addstr(&c, " no-progress");
+			if (args.include_tag)   strbuf_addstr(&c, " include-tag");
+			if (prefer_ofs_delta)   strbuf_addstr(&c, " ofs-delta");
+			packet_buf_write(&req_buf, "want %s%s\n", remote_hex, c.buf);
+			strbuf_release(&c);
+		} else
+			packet_buf_write(&req_buf, "want %s\n", remote_hex);
+		fetching++;
+	}
+
+	if (!fetching) {
+		strbuf_release(&req_buf);
+		packet_flush(fd[1]);
+		return 1;
+	}
+
+	if (is_repository_shallow())
+		write_shallow_commits(&req_buf, 1);
+	if (args.depth > 0)
+		packet_buf_write(&req_buf, "deepen %d", args.depth);
+	packet_buf_flush(&req_buf);
+	state_len = req_buf.len;
+
+	if (args.depth > 0) {
+		char line[1024];
+		unsigned char sha1[20];
+
+		send_request(fd[1], &req_buf);
+		while (packet_read_line(fd[0], line, sizeof(line))) {
+			if (!prefixcmp(line, "shallow ")) {
+				if (get_sha1_hex(line + 8, sha1))
+					die("invalid shallow line: %s", line);
+				register_shallow(sha1);
+				continue;
+			}
+			if (!prefixcmp(line, "unshallow ")) {
+				if (get_sha1_hex(line + 10, sha1))
+					die("invalid unshallow line: %s", line);
+				if (!lookup_object(sha1))
+					die("object not found: %s", 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);
+				continue;
+			}
+			die("expected shallow/unshallow, got %s", line);
+		}
+	} else if (!args.stateless_rpc)
+		send_request(fd[1], &req_buf);
+
+	if (!args.stateless_rpc) {
+		/* If we aren't using the stateless-rpc interface
+		 * we don't need to retain the headers.
+		 */
+		strbuf_setlen(&req_buf, 0);
+		state_len = 0;
+	}
+
+	flushes = 0;
+	retval = -1;
+	while ((sha1 = get_rev())) {
+		packet_buf_write(&req_buf, "have %s\n", sha1_to_hex(sha1));
+		if (args.verbose)
+			fprintf(stderr, "have %s\n", sha1_to_hex(sha1));
+		in_vain++;
+		if (flush_at <= ++count) {
+			int ack;
+
+			packet_buf_flush(&req_buf);
+			send_request(fd[1], &req_buf);
+			strbuf_setlen(&req_buf, state_len);
+			flushes++;
+			flush_at = next_flush(count);
+
+			/*
+			 * We keep one window "ahead" of the other side, and
+			 * will wait for an ACK only on the next one
+			 */
+			if (!args.stateless_rpc && count == INITIAL_FLUSH)
+				continue;
+
+			consume_shallow_list(fd[0]);
+			do {
+				ack = get_ack(fd[0], result_sha1);
+				if (args.verbose && ack)
+					fprintf(stderr, "got ack %d %s\n", ack,
+							sha1_to_hex(result_sha1));
+				switch (ack) {
+				case ACK:
+					flushes = 0;
+					multi_ack = 0;
+					retval = 0;
+					goto done;
+				case ACK_common:
+				case ACK_ready:
+				case ACK_continue: {
+					struct commit *commit =
+						lookup_commit(result_sha1);
+					if (args.stateless_rpc
+					 && ack == ACK_common
+					 && !(commit->object.flags & 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);
+						packet_buf_write(&req_buf, "have %s\n", hex);
+						state_len = req_buf.len;
+					}
+					mark_common(commit, 0, 1);
+					retval = 0;
+					in_vain = 0;
+					got_continue = 1;
+					if (ack == ACK_ready) {
+						rev_list = NULL;
+						got_ready = 1;
+					}
+					break;
+					}
+				}
+			} while (ack);
+			flushes--;
+			if (got_continue && MAX_IN_VAIN < in_vain) {
+				if (args.verbose)
+					fprintf(stderr, "giving up\n");
+				break; /* give up */
+			}
+		}
+	}
+done:
+	if (!got_ready || !no_done) {
+		packet_buf_write(&req_buf, "done\n");
+		send_request(fd[1], &req_buf);
+	}
+	if (args.verbose)
+		fprintf(stderr, "done\n");
+	if (retval != 0) {
+		multi_ack = 0;
+		flushes++;
+	}
+	strbuf_release(&req_buf);
+
+	consume_shallow_list(fd[0]);
+	while (flushes || multi_ack) {
+		int ack = get_ack(fd[0], result_sha1);
+		if (ack) {
+			if (args.verbose)
+				fprintf(stderr, "got ack (%d) %s\n", ack,
+					sha1_to_hex(result_sha1));
+			if (ack == ACK)
+				return 0;
+			multi_ack = 1;
+			continue;
+		}
+		flushes--;
+	}
+	/* it is no error to fetch into a completely empty repo */
+	return count ? retval : 0;
+}
+
+static struct commit_list *complete;
+
+static int mark_complete(const char *path, const unsigned char *sha1, int flag, void *cb_data)
+{
+	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->sha1);
+	}
+	if (o && o->type == OBJ_COMMIT) {
+		struct commit *commit = (struct commit *)o;
+		commit->object.flags |= COMPLETE;
+		commit_list_insert_by_date(commit, &complete);
+	}
+	return 0;
+}
+
+static void mark_recent_complete_commits(unsigned long cutoff)
+{
+	while (complete && cutoff <= complete->item->date) {
+		if (args.verbose)
+			fprintf(stderr, "Marking %s as complete\n",
+				sha1_to_hex(complete->item->object.sha1));
+		pop_most_recent_commit(&complete, COMPLETE);
+	}
+}
+
+static void filter_refs(struct ref **refs, int nr_match, char **match)
+{
+	struct ref **return_refs;
+	struct ref *newlist = NULL;
+	struct ref **newtail = &newlist;
+	struct ref *ref, *next;
+	struct ref *fastarray[32];
+
+	if (nr_match && !args.fetch_all) {
+		if (ARRAY_SIZE(fastarray) < nr_match)
+			return_refs = xcalloc(nr_match, sizeof(struct ref *));
+		else {
+			return_refs = fastarray;
+			memset(return_refs, 0, sizeof(struct ref *) * nr_match);
+		}
+	}
+	else
+		return_refs = NULL;
+
+	for (ref = *refs; ref; ref = next) {
+		next = ref->next;
+		if (!memcmp(ref->name, "refs/", 5) &&
+		    check_ref_format(ref->name + 5))
+			; /* trash */
+		else if (args.fetch_all &&
+			 (!args.depth || prefixcmp(ref->name, "refs/tags/") )) {
+			*newtail = ref;
+			ref->next = NULL;
+			newtail = &ref->next;
+			continue;
+		}
+		else {
+			int order = path_match(ref->name, nr_match, match);
+			if (order) {
+				return_refs[order-1] = ref;
+				continue; /* we will link it later */
+			}
+		}
+		free(ref);
+	}
+
+	if (!args.fetch_all) {
+		int i;
+		for (i = 0; i < nr_match; i++) {
+			ref = return_refs[i];
+			if (ref) {
+				*newtail = ref;
+				ref->next = NULL;
+				newtail = &ref->next;
+			}
+		}
+		if (return_refs != fastarray)
+			free(return_refs);
+	}
+	*refs = newlist;
+}
+
+static int everything_local(struct ref **refs, int nr_match, char **match)
+{
+	struct ref *ref;
+	int retval;
+	unsigned long cutoff = 0;
+
+	save_commit_buffer = 0;
+
+	for (ref = *refs; ref; ref = ref->next) {
+		struct object *o;
+
+		o = parse_object(ref->old_sha1);
+		if (!o)
+			continue;
+
+		/* 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).
+		 */
+		if (o->type == OBJ_COMMIT) {
+			struct commit *commit = (struct commit *)o;
+			if (!cutoff || cutoff < commit->date)
+				cutoff = commit->date;
+		}
+	}
+
+	if (!args.depth) {
+		for_each_ref(mark_complete, NULL);
+		if (cutoff)
+			mark_recent_complete_commits(cutoff);
+	}
+
+	/*
+	 * Mark all complete remote refs as common refs.
+	 * Don't mark them common yet; the server has to be told so first.
+	 */
+	for (ref = *refs; ref; ref = ref->next) {
+		struct object *o = deref_tag(lookup_object(ref->old_sha1),
+					     NULL, 0);
+
+		if (!o || o->type != OBJ_COMMIT || !(o->flags & COMPLETE))
+			continue;
+
+		if (!(o->flags & SEEN)) {
+			rev_list_push((struct commit *)o, COMMON_REF | SEEN);
+
+			mark_common((struct commit *)o, 1, 1);
+		}
+	}
+
+	filter_refs(refs, nr_match, match);
+
+	for (retval = 1, ref = *refs; ref ; ref = ref->next) {
+		const unsigned char *remote = ref->old_sha1;
+		unsigned char local[20];
+		struct object *o;
+
+		o = lookup_object(remote);
+		if (!o || !(o->flags & COMPLETE)) {
+			retval = 0;
+			if (!args.verbose)
+				continue;
+			fprintf(stderr,
+				"want %s (%s)\n", sha1_to_hex(remote),
+				ref->name);
+			continue;
+		}
+
+		hashcpy(ref->new_sha1, local);
+		if (!args.verbose)
+			continue;
+		fprintf(stderr,
+			"already have %s (%s)\n", sha1_to_hex(remote),
+			ref->name);
+	}
+	return retval;
+}
+
+static int sideband_demux(int in, int out, void *data)
+{
+	int *xd = data;
+
+	int ret = recv_sideband("fetch-pack", xd[0], out);
+	close(out);
+	return ret;
+}
+
+static int get_pack(int xd[2], char **pack_lockfile)
+{
+	struct async demux;
+	const char *argv[20];
+	char keep_arg[256];
+	char hdr_arg[256];
+	const char **av;
+	int do_keep = args.keep_pack;
+	struct child_process cmd;
+
+	memset(&demux, 0, sizeof(demux));
+	if (use_sideband) {
+		/* xd[] is talking with upload-pack; subprocess reads from
+		 * xd[0], spits out band#2 to stderr, and feeds us band#1
+		 * through demux->out.
+		 */
+		demux.proc = sideband_demux;
+		demux.data = xd;
+		demux.out = -1;
+		if (start_async(&demux))
+			die("fetch-pack: unable to fork off sideband"
+			    " demultiplexer");
+	}
+	else
+		demux.out = xd[0];
+
+	memset(&cmd, 0, sizeof(cmd));
+	cmd.argv = argv;
+	av = argv;
+	*hdr_arg = 0;
+	if (!args.keep_pack && unpack_limit) {
+		struct pack_header header;
+
+		if (read_pack_header(demux.out, &header))
+			die("protocol error: bad pack header");
+		snprintf(hdr_arg, sizeof(hdr_arg),
+			 "--pack_header=%"PRIu32",%"PRIu32,
+			 ntohl(header.hdr_version), ntohl(header.hdr_entries));
+		if (ntohl(header.hdr_entries) < unpack_limit)
+			do_keep = 0;
+		else
+			do_keep = 1;
+	}
+
+	if (do_keep) {
+		if (pack_lockfile)
+			cmd.out = -1;
+		*av++ = "index-pack";
+		*av++ = "--stdin";
+		if (!args.quiet && !args.no_progress)
+			*av++ = "-v";
+		if (args.use_thin_pack)
+			*av++ = "--fix-thin";
+		if (args.lock_pack || unpack_limit) {
+			int s = sprintf(keep_arg,
+					"--keep=fetch-pack %"PRIuMAX " on ", (uintmax_t) getpid());
+			if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
+				strcpy(keep_arg + s, "localhost");
+			*av++ = keep_arg;
+		}
+	}
+	else {
+		*av++ = "unpack-objects";
+		if (args.quiet)
+			*av++ = "-q";
+	}
+	if (*hdr_arg)
+		*av++ = hdr_arg;
+	*av++ = NULL;
+
+	cmd.in = demux.out;
+	cmd.git_cmd = 1;
+	if (start_command(&cmd))
+		die("fetch-pack: unable to fork off %s", argv[0]);
+	if (do_keep && pack_lockfile) {
+		*pack_lockfile = index_pack_lockfile(cmd.out);
+		close(cmd.out);
+	}
+
+	if (finish_command(&cmd))
+		die("%s failed", argv[0]);
+	if (use_sideband && finish_async(&demux))
+		die("error in sideband demultiplexer");
+	return 0;
+}
+
+static struct ref *do_fetch_pack(int fd[2],
+		const struct ref *orig_ref,
+		int nr_match,
+		char **match,
+		char **pack_lockfile)
+{
+	struct ref *ref = copy_ref_list(orig_ref);
+	unsigned char sha1[20];
+
+	if (is_repository_shallow() && !server_supports("shallow"))
+		die("Server does not support shallow clients");
+	if (server_supports("multi_ack_detailed")) {
+		if (args.verbose)
+			fprintf(stderr, "Server supports multi_ack_detailed\n");
+		multi_ack = 2;
+		if (server_supports("no-done")) {
+			if (args.verbose)
+				fprintf(stderr, "Server supports no-done\n");
+			if (args.stateless_rpc)
+				no_done = 1;
+		}
+	}
+	else if (server_supports("multi_ack")) {
+		if (args.verbose)
+			fprintf(stderr, "Server supports multi_ack\n");
+		multi_ack = 1;
+	}
+	if (server_supports("side-band-64k")) {
+		if (args.verbose)
+			fprintf(stderr, "Server supports side-band-64k\n");
+		use_sideband = 2;
+	}
+	else if (server_supports("side-band")) {
+		if (args.verbose)
+			fprintf(stderr, "Server supports side-band\n");
+		use_sideband = 1;
+	}
+	if (server_supports("ofs-delta")) {
+		if (args.verbose)
+			fprintf(stderr, "Server supports ofs-delta\n");
+	} else
+		prefer_ofs_delta = 0;
+	if (everything_local(&ref, nr_match, match)) {
+		packet_flush(fd[1]);
+		goto all_done;
+	}
+	if (find_common(fd, sha1, ref) < 0)
+		if (!args.keep_pack)
+			/* When cloning, it is not unusual to have
+			 * no common commit.
+			 */
+			warning("no common commits");
+
+	if (args.stateless_rpc)
+		packet_flush(fd[1]);
+	if (get_pack(fd, pack_lockfile))
+		die("git fetch-pack: fetch failed.");
+
+ all_done:
+	return ref;
+}
+
+static int remove_duplicates(int nr_heads, char **heads)
+{
+	int src, dst;
+
+	for (src = dst = 0; src < nr_heads; src++) {
+		/* If heads[src] is different from any of
+		 * heads[0..dst], push it in.
+		 */
+		int i;
+		for (i = 0; i < dst; i++) {
+			if (!strcmp(heads[i], heads[src]))
+				break;
+		}
+		if (i < dst)
+			continue;
+		if (src != dst)
+			heads[dst] = heads[src];
+		dst++;
+	}
+	return dst;
+}
+
+static int fetch_pack_config(const char *var, const char *value, void *cb)
+{
+	if (strcmp(var, "fetch.unpacklimit") == 0) {
+		fetch_unpack_limit = git_config_int(var, value);
+		return 0;
+	}
+
+	if (strcmp(var, "transfer.unpacklimit") == 0) {
+		transfer_unpack_limit = git_config_int(var, value);
+		return 0;
+	}
+
+	if (strcmp(var, "repack.usedeltabaseoffset") == 0) {
+		prefer_ofs_delta = git_config_bool(var, value);
+		return 0;
+	}
+
+	return git_default_config(var, value, cb);
+}
+
+static struct lock_file lock;
+
+static void fetch_pack_setup(void)
+{
+	static int did_setup;
+	if (did_setup)
+		return;
+	git_config(fetch_pack_config, NULL);
+	if (0 <= transfer_unpack_limit)
+		unpack_limit = transfer_unpack_limit;
+	else if (0 <= fetch_unpack_limit)
+		unpack_limit = fetch_unpack_limit;
+	did_setup = 1;
+}
+
+int cmd_fetch_pack(int argc, const char **argv, const char *prefix)
+{
+	int i, ret, nr_heads;
+	struct ref *ref = NULL;
+	char *dest = NULL, **heads;
+	int fd[2];
+	char *pack_lockfile = NULL;
+	char **pack_lockfile_ptr = NULL;
+	struct child_process *conn;
+
+	packet_trace_identity("fetch-pack");
+
+	nr_heads = 0;
+	heads = NULL;
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+
+		if (*arg == '-') {
+			if (!prefixcmp(arg, "--upload-pack=")) {
+				args.uploadpack = arg + 14;
+				continue;
+			}
+			if (!prefixcmp(arg, "--exec=")) {
+				args.uploadpack = arg + 7;
+				continue;
+			}
+			if (!strcmp("--quiet", arg) || !strcmp("-q", arg)) {
+				args.quiet = 1;
+				continue;
+			}
+			if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
+				args.lock_pack = args.keep_pack;
+				args.keep_pack = 1;
+				continue;
+			}
+			if (!strcmp("--thin", arg)) {
+				args.use_thin_pack = 1;
+				continue;
+			}
+			if (!strcmp("--include-tag", arg)) {
+				args.include_tag = 1;
+				continue;
+			}
+			if (!strcmp("--all", arg)) {
+				args.fetch_all = 1;
+				continue;
+			}
+			if (!strcmp("-v", arg)) {
+				args.verbose = 1;
+				continue;
+			}
+			if (!prefixcmp(arg, "--depth=")) {
+				args.depth = strtol(arg + 8, NULL, 0);
+				continue;
+			}
+			if (!strcmp("--no-progress", arg)) {
+				args.no_progress = 1;
+				continue;
+			}
+			if (!strcmp("--stateless-rpc", arg)) {
+				args.stateless_rpc = 1;
+				continue;
+			}
+			if (!strcmp("--lock-pack", arg)) {
+				args.lock_pack = 1;
+				pack_lockfile_ptr = &pack_lockfile;
+				continue;
+			}
+			usage(fetch_pack_usage);
+		}
+		dest = (char *)arg;
+		heads = (char **)(argv + i + 1);
+		nr_heads = argc - i - 1;
+		break;
+	}
+	if (!dest)
+		usage(fetch_pack_usage);
+
+	if (args.stateless_rpc) {
+		conn = NULL;
+		fd[0] = 0;
+		fd[1] = 1;
+	} else {
+		conn = git_connect(fd, (char *)dest, args.uploadpack,
+				   args.verbose ? CONNECT_VERBOSE : 0);
+	}
+
+	get_remote_heads(fd[0], &ref, 0, NULL, 0, NULL);
+
+	ref = fetch_pack(&args, fd, conn, ref, dest,
+		nr_heads, heads, pack_lockfile_ptr);
+	if (pack_lockfile) {
+		printf("lock %s\n", pack_lockfile);
+		fflush(stdout);
+	}
+	close(fd[0]);
+	close(fd[1]);
+	if (finish_connect(conn))
+		ref = NULL;
+	ret = !ref;
+
+	if (!ret && nr_heads) {
+		/* If the heads to pull were given, we should have
+		 * consumed all of them by matching the remote.
+		 * Otherwise, 'git fetch remote no-such-ref' would
+		 * silently succeed without issuing an error.
+		 */
+		for (i = 0; i < nr_heads; i++)
+			if (heads[i] && heads[i][0]) {
+				error("no such remote ref %s", heads[i]);
+				ret = 1;
+			}
+	}
+	while (ref) {
+		printf("%s %s\n",
+		       sha1_to_hex(ref->old_sha1), ref->name);
+		ref = ref->next;
+	}
+
+	return ret;
+}
+
+struct ref *fetch_pack(struct fetch_pack_args *my_args,
+		       int fd[], struct child_process *conn,
+		       const struct ref *ref,
+		const char *dest,
+		int nr_heads,
+		char **heads,
+		char **pack_lockfile)
+{
+	struct stat st;
+	struct ref *ref_cpy;
+
+	fetch_pack_setup();
+	if (&args != my_args)
+		memcpy(&args, my_args, sizeof(args));
+	if (args.depth > 0) {
+		if (stat(git_path("shallow"), &st))
+			st.st_mtime = 0;
+	}
+
+	if (heads && nr_heads)
+		nr_heads = remove_duplicates(nr_heads, heads);
+	if (!ref) {
+		packet_flush(fd[1]);
+		die("no matching remote head");
+	}
+	ref_cpy = do_fetch_pack(fd, ref, nr_heads, heads, pack_lockfile);
+
+	if (args.depth > 0) {
+		struct cache_time mtime;
+		struct strbuf sb = STRBUF_INIT;
+		char *shallow = git_path("shallow");
+		int fd;
+
+		mtime.sec = st.st_mtime;
+		mtime.nsec = ST_MTIME_NSEC(st);
+		if (stat(shallow, &st)) {
+			if (mtime.sec)
+				die("shallow file was removed during fetch");
+		} else if (st.st_mtime != mtime.sec
+#ifdef USE_NSEC
+				|| ST_MTIME_NSEC(st) != mtime.nsec
+#endif
+			  )
+			die("shallow file was changed during fetch");
+
+		fd = hold_lock_file_for_update(&lock, shallow,
+					       LOCK_DIE_ON_ERROR);
+		if (!write_shallow_commits(&sb, 0)
+		 || write_in_full(fd, sb.buf, sb.len) != sb.len) {
+			unlink_or_warn(shallow);
+			rollback_lock_file(&lock);
+		} else {
+			commit_lock_file(&lock);
+		}
+		strbuf_release(&sb);
+	}
+
+	reprepare_packed_git();
+	return ref_cpy;
+}