1 files changed, 670 insertions, 335 deletions

diff --git a/upload-pack.c b/upload-pack.c
index fcf279843a..43342ac161 100644
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -1,470 +1,773 @@
-#include <signal.h>
-#include <sys/wait.h>
-#include <sys/poll.h>
 #include "cache.h"
 #include "refs.h"
 #include "pkt-line.h"
+#include "sideband.h"
 #include "tag.h"
 #include "object.h"
 #include "commit.h"
 #include "exec_cmd.h"
-
-static const char upload_pack_usage[] = "git-upload-pack [--strict] [--timeout=nn] <dir>";
-
-#define THEY_HAVE (1U << 0)
-#define OUR_REF (1U << 1)
-#define WANTED (1U << 2)
-static int multi_ack, nr_our_refs;
-static int use_thin_pack;
+#include "diff.h"
+#include "revision.h"
+#include "list-objects.h"
+#include "run-command.h"
+#include "connect.h"
+#include "sigchain.h"
+#include "version.h"
+#include "string-list.h"
+
+static const char upload_pack_usage[] = "git upload-pack [--strict] [--timeout=<n>] <dir>";
+
+/* bits #0..7 in revision.h, #8..10 in commit.c */
+#define THEY_HAVE	(1u << 11)
+#define OUR_REF		(1u << 12)
+#define WANTED		(1u << 13)
+#define COMMON_KNOWN	(1u << 14)
+#define REACHABLE	(1u << 15)
+
+#define SHALLOW		(1u << 16)
+#define NOT_SHALLOW	(1u << 17)
+#define CLIENT_SHALLOW	(1u << 18)
+#define HIDDEN_REF	(1u << 19)
+
+static unsigned long oldest_have;
+
+static int multi_ack;
+static int no_done;
+static int use_thin_pack, use_ofs_delta, use_include_tag;
+static int no_progress, daemon_mode;
+static int allow_tip_sha1_in_want;
+static int shallow_nr;
 static struct object_array have_obj;
 static struct object_array want_obj;
+static struct object_array extra_edge_obj;
 static unsigned int timeout;
+static int keepalive = 5;
+/* 0 for no sideband,
+ * otherwise maximum packet size (up to 65520 bytes).
+ */
 static int use_sideband;
+static int advertise_refs;
+static int stateless_rpc;
 
 static void reset_timeout(void)
 {
 	alarm(timeout);
 }
 
-static int strip(char *line, int len)
-{
-	if (len && line[len-1] == '\n')
-		line[--len] = 0;
-	return len;
-}
-
-#define PACKET_MAX 1000
 static ssize_t send_client_data(int fd, const char *data, ssize_t sz)
 {
-	ssize_t ssz;
-	const char *p;
-
-	if (!data) {
-		if (!use_sideband)
-			return 0;
-		packet_flush(1);
-	}
-
-	if (!use_sideband) {
-		if (fd == 3)
-			/* emergency quit */
-			fd = 2;
-		if (fd == 2) {
-			xwrite(fd, data, sz);
-			return sz;
-		}
-		return safe_write(fd, data, sz);
-	}
-	p = data;
-	ssz = sz;
-	while (sz) {
-		unsigned n;
-		char hdr[5];
-
-		n = sz;
-		if (PACKET_MAX - 5 < n)
-			n = PACKET_MAX - 5;
-		sprintf(hdr, "%04x", n + 5);
-		hdr[4] = fd;
-		safe_write(1, hdr, 5);
-		safe_write(1, p, n);
-		p += n;
-		sz -= n;
+	if (use_sideband)
+		return send_sideband(1, fd, data, sz, use_sideband);
+	if (fd == 3)
+		/* emergency quit */
+		fd = 2;
+	if (fd == 2) {
+		/* XXX: are we happy to lose stuff here? */
+		xwrite(fd, data, sz);
+		return sz;
 	}
-	return ssz;
+	write_or_die(fd, data, sz);
+	return sz;
 }
 
 static void create_pack_file(void)
 {
-	/* Pipes between rev-list to pack-objects, pack-objects to us
-	 * and pack-objects error stream for progress bar.
-	 */
-	int lp_pipe[2], pu_pipe[2], pe_pipe[2];
-	pid_t pid_rev_list, pid_pack_objects;
-	int create_full_pack = (nr_our_refs == want_obj.nr && !have_obj.nr);
+	struct child_process pack_objects;
 	char data[8193], progress[128];
 	char abort_msg[] = "aborting due to possible repository "
 		"corruption on the remote side.";
 	int buffered = -1;
-
-	if (pipe(lp_pipe) < 0)
-		die("git-upload-pack: unable to create pipe");
-	pid_rev_list = fork();
-	if (pid_rev_list < 0)
-		die("git-upload-pack: unable to fork git-rev-list");
-
-	if (!pid_rev_list) {
-		int i;
-		int args;
-		const char **argv;
-		const char **p;
-		char *buf;
-
-		if (create_full_pack) {
-			args = 10;
-			use_thin_pack = 0; /* no point doing it */
-		}
-		else
-			args = have_obj.nr + want_obj.nr + 5;
-		p = xmalloc(args * sizeof(char *));
-		argv = (const char **) p;
-		buf = xmalloc(args * 45);
-
-		dup2(lp_pipe[1], 1);
-		close(0);
-		close(lp_pipe[0]);
-		close(lp_pipe[1]);
-		*p++ = "rev-list";
-		*p++ = use_thin_pack ? "--objects-edge" : "--objects";
-		if (create_full_pack)
-			*p++ = "--all";
-		else {
-			for (i = 0; i < want_obj.nr; i++) {
-				struct object *o = want_obj.objects[i].item;
-				*p++ = buf;
-				memcpy(buf, sha1_to_hex(o->sha1), 41);
-				buf += 41;
-			}
-		}
-		if (!create_full_pack)
-			for (i = 0; i < have_obj.nr; i++) {
-				struct object *o = have_obj.objects[i].item;
-				*p++ = buf;
-				*buf++ = '^';
-				memcpy(buf, sha1_to_hex(o->sha1), 41);
-				buf += 41;
-			}
-		*p++ = NULL;
-		execv_git_cmd(argv);
-		die("git-upload-pack: unable to exec git-rev-list");
-	}
-
-	if (pipe(pu_pipe) < 0)
-		die("git-upload-pack: unable to create pipe");
-	if (pipe(pe_pipe) < 0)
-		die("git-upload-pack: unable to create pipe");
-	pid_pack_objects = fork();
-	if (pid_pack_objects < 0) {
-		/* daemon sets things up to ignore TERM */
-		kill(pid_rev_list, SIGKILL);
-		die("git-upload-pack: unable to fork git-pack-objects");
-	}
-	if (!pid_pack_objects) {
-		dup2(lp_pipe[0], 0);
-		dup2(pu_pipe[1], 1);
-		dup2(pe_pipe[1], 2);
-
-		close(lp_pipe[0]);
-		close(lp_pipe[1]);
-		close(pu_pipe[0]);
-		close(pu_pipe[1]);
-		close(pe_pipe[0]);
-		close(pe_pipe[1]);
-		execl_git_cmd("pack-objects", "--stdout", "--progress", NULL);
-		kill(pid_rev_list, SIGKILL);
-		die("git-upload-pack: unable to exec git-pack-objects");
+	ssize_t sz;
+	const char *argv[12];
+	int i, arg = 0;
+	FILE *pipe_fd;
+	char *shallow_file = NULL;
+
+	if (shallow_nr) {
+		shallow_file = setup_temporary_shallow();
+		argv[arg++] = "--shallow-file";
+		argv[arg++] = shallow_file;
 	}
-
-	close(lp_pipe[0]);
-	close(lp_pipe[1]);
-
-	/* We read from pe_pipe[0] to capture stderr output for
-	 * progress bar, and pu_pipe[0] to capture the pack data.
+	argv[arg++] = "pack-objects";
+	argv[arg++] = "--revs";
+	if (use_thin_pack)
+		argv[arg++] = "--thin";
+
+	argv[arg++] = "--stdout";
+	if (!no_progress)
+		argv[arg++] = "--progress";
+	if (use_ofs_delta)
+		argv[arg++] = "--delta-base-offset";
+	if (use_include_tag)
+		argv[arg++] = "--include-tag";
+	argv[arg++] = NULL;
+
+	memset(&pack_objects, 0, sizeof(pack_objects));
+	pack_objects.in = -1;
+	pack_objects.out = -1;
+	pack_objects.err = -1;
+	pack_objects.git_cmd = 1;
+	pack_objects.argv = argv;
+
+	if (start_command(&pack_objects))
+		die("git upload-pack: unable to fork git-pack-objects");
+
+	pipe_fd = xfdopen(pack_objects.in, "w");
+
+	for (i = 0; i < want_obj.nr; i++)
+		fprintf(pipe_fd, "%s\n",
+			sha1_to_hex(want_obj.objects[i].item->sha1));
+	fprintf(pipe_fd, "--not\n");
+	for (i = 0; i < have_obj.nr; i++)
+		fprintf(pipe_fd, "%s\n",
+			sha1_to_hex(have_obj.objects[i].item->sha1));
+	for (i = 0; i < extra_edge_obj.nr; i++)
+		fprintf(pipe_fd, "%s\n",
+			sha1_to_hex(extra_edge_obj.objects[i].item->sha1));
+	fprintf(pipe_fd, "\n");
+	fflush(pipe_fd);
+	fclose(pipe_fd);
+
+	/* We read from pack_objects.err to capture stderr output for
+	 * progress bar, and pack_objects.out to capture the pack data.
 	 */
-	close(pe_pipe[1]);
-	close(pu_pipe[1]);
 
 	while (1) {
-		const char *who;
 		struct pollfd pfd[2];
-		pid_t pid;
-		int status;
-		ssize_t sz;
 		int pe, pu, pollsize;
+		int ret;
 
 		reset_timeout();
 
 		pollsize = 0;
 		pe = pu = -1;
 
-		if (0 <= pu_pipe[0]) {
-			pfd[pollsize].fd = pu_pipe[0];
+		if (0 <= pack_objects.out) {
+			pfd[pollsize].fd = pack_objects.out;
 			pfd[pollsize].events = POLLIN;
 			pu = pollsize;
 			pollsize++;
 		}
-		if (0 <= pe_pipe[0]) {
-			pfd[pollsize].fd = pe_pipe[0];
+		if (0 <= pack_objects.err) {
+			pfd[pollsize].fd = pack_objects.err;
 			pfd[pollsize].events = POLLIN;
 			pe = pollsize;
 			pollsize++;
 		}
 
-		if (pollsize) {
-			if (poll(pfd, pollsize, -1) < 0) {
-				if (errno != EINTR) {
-					error("poll failed, resuming: %s",
-					      strerror(errno));
-					sleep(1);
-				}
-				continue;
-			}
-			if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
-				/* Data ready; we keep the last byte
-				 * to ourselves in case we detect
-				 * broken rev-list, so that we can
-				 * leave the stream corrupted.  This
-				 * is unfortunate -- unpack-objects
-				 * would happily accept a valid pack
-				 * data with trailing garbage, so
-				 * appending garbage after we pass all
-				 * the pack data is not good enough to
-				 * signal breakage to downstream.
-				 */
-				char *cp = data;
-				ssize_t outsz = 0;
-				if (0 <= buffered) {
-					*cp++ = buffered;
-					outsz++;
-				}
-				sz = read(pu_pipe[0], cp,
-					  sizeof(data) - outsz);
-				if (0 < sz)
-						;
-				else if (sz == 0) {
-					close(pu_pipe[0]);
-					pu_pipe[0] = -1;
-				}
-				else
-					goto fail;
-				sz += outsz;
-				if (1 < sz) {
-					buffered = data[sz-1] & 0xFF;
-					sz--;
-				}
-				else
-					buffered = -1;
-				sz = send_client_data(1, data, sz);
-				if (sz < 0)
-					goto fail;
+		if (!pollsize)
+			break;
+
+		ret = poll(pfd, pollsize, 1000 * keepalive);
+		if (ret < 0) {
+			if (errno != EINTR) {
+				error("poll failed, resuming: %s",
+				      strerror(errno));
+				sleep(1);
 			}
-			if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
-				/* Status ready; we ship that in the side-band
-				 * or dump to the standard error.
-				 */
-				sz = read(pe_pipe[0], progress,
-					  sizeof(progress));
-				if (0 < sz)
-					send_client_data(2, progress, sz);
-				else if (sz == 0) {
-					close(pe_pipe[0]);
-					pe_pipe[0] = -1;
-				}
-				else
-					goto fail;
+			continue;
+		}
+		if (0 <= pe && (pfd[pe].revents & (POLLIN|POLLHUP))) {
+			/* Status ready; we ship that in the side-band
+			 * or dump to the standard error.
+			 */
+			sz = xread(pack_objects.err, progress,
+				  sizeof(progress));
+			if (0 < sz)
+				send_client_data(2, progress, sz);
+			else if (sz == 0) {
+				close(pack_objects.err);
+				pack_objects.err = -1;
 			}
+			else
+				goto fail;
+			/* give priority to status messages */
+			continue;
 		}
-
-		/* See if the children are still there */
-		if (pid_rev_list || pid_pack_objects) {
-			pid = waitpid(-1, &status, WNOHANG);
-			if (!pid)
-				continue;
-			who = ((pid == pid_rev_list) ? "git-rev-list" :
-			       (pid == pid_pack_objects) ? "git-pack-objects" :
-			       NULL);
-			if (!who) {
-				if (pid < 0) {
-					error("git-upload-pack: %s",
-					      strerror(errno));
-					goto fail;
-				}
-				error("git-upload-pack: we weren't "
-				      "waiting for %d", pid);
-				continue;
+		if (0 <= pu && (pfd[pu].revents & (POLLIN|POLLHUP))) {
+			/* Data ready; we keep the last byte to ourselves
+			 * in case we detect broken rev-list, so that we
+			 * can leave the stream corrupted.  This is
+			 * unfortunate -- unpack-objects would happily
+			 * accept a valid packdata with trailing garbage,
+			 * so appending garbage after we pass all the
+			 * pack data is not good enough to signal
+			 * breakage to downstream.
+			 */
+			char *cp = data;
+			ssize_t outsz = 0;
+			if (0 <= buffered) {
+				*cp++ = buffered;
+				outsz++;
+			}
+			sz = xread(pack_objects.out, cp,
+				  sizeof(data) - outsz);
+			if (0 < sz)
+				;
+			else if (sz == 0) {
+				close(pack_objects.out);
+				pack_objects.out = -1;
 			}
-			if (!WIFEXITED(status) || WEXITSTATUS(status) > 0) {
-				error("git-upload-pack: %s died with error.",
-				      who);
+			else
 				goto fail;
+			sz += outsz;
+			if (1 < sz) {
+				buffered = data[sz-1] & 0xFF;
+				sz--;
 			}
-			if (pid == pid_rev_list)
-				pid_rev_list = 0;
-			if (pid == pid_pack_objects)
-				pid_pack_objects = 0;
-			if (pid_rev_list || pid_pack_objects)
-				continue;
-		}
-
-		/* both died happily */
-		if (pollsize)
-			continue;
-
-		/* flush the data */
-		if (0 <= buffered) {
-			data[0] = buffered;
-			sz = send_client_data(1, data, 1);
+			else
+				buffered = -1;
+			sz = send_client_data(1, data, sz);
 			if (sz < 0)
 				goto fail;
-			fprintf(stderr, "flushed.\n");
 		}
-		send_client_data(1, NULL, 0);
-		return;
+
+		/*
+		 * We hit the keepalive timeout without saying anything; send
+		 * an empty message on the data sideband just to let the other
+		 * side know we're still working on it, but don't have any data
+		 * yet.
+		 *
+		 * If we don't have a sideband channel, there's no room in the
+		 * protocol to say anything, so those clients are just out of
+		 * luck.
+		 */
+		if (!ret && use_sideband) {
+			static const char buf[] = "0005\1";
+			write_or_die(1, buf, 5);
+		}
 	}
+
+	if (finish_command(&pack_objects)) {
+		error("git upload-pack: git-pack-objects died with error.");
+		goto fail;
+	}
+	if (shallow_file) {
+		if (*shallow_file)
+			unlink(shallow_file);
+		free(shallow_file);
+	}
+
+	/* flush the data */
+	if (0 <= buffered) {
+		data[0] = buffered;
+		sz = send_client_data(1, data, 1);
+		if (sz < 0)
+			goto fail;
+		fprintf(stderr, "flushed.\n");
+	}
+	if (use_sideband)
+		packet_flush(1);
+	return;
+
  fail:
-	if (pid_pack_objects)
-		kill(pid_pack_objects, SIGKILL);
-	if (pid_rev_list)
-		kill(pid_rev_list, SIGKILL);
 	send_client_data(3, abort_msg, sizeof(abort_msg));
-	die("git-upload-pack: %s", abort_msg);
+	die("git upload-pack: %s", abort_msg);
 }
 
 static int got_sha1(char *hex, unsigned char *sha1)
 {
 	struct object *o;
+	int we_knew_they_have = 0;
 
 	if (get_sha1_hex(hex, sha1))
-		die("git-upload-pack: expected SHA1 object, got '%s'", hex);
+		die("git upload-pack: expected SHA1 object, got '%s'", hex);
 	if (!has_sha1_file(sha1))
-		return 0;
+		return -1;
 
-	o = lookup_object(sha1);
-	if (!(o && o->parsed))
-		o = parse_object(sha1);
+	o = parse_object(sha1);
 	if (!o)
 		die("oops (%s)", sha1_to_hex(sha1));
 	if (o->type == OBJ_COMMIT) {
 		struct commit_list *parents;
+		struct commit *commit = (struct commit *)o;
 		if (o->flags & THEY_HAVE)
-			return 0;
-		o->flags |= THEY_HAVE;
-		for (parents = ((struct commit*)o)->parents;
+			we_knew_they_have = 1;
+		else
+			o->flags |= THEY_HAVE;
+		if (!oldest_have || (commit->date < oldest_have))
+			oldest_have = commit->date;
+		for (parents = commit->parents;
 		     parents;
 		     parents = parents->next)
 			parents->item->object.flags |= THEY_HAVE;
 	}
-	add_object_array(o, NULL, &have_obj);
+	if (!we_knew_they_have) {
+		add_object_array(o, NULL, &have_obj);
+		return 1;
+	}
+	return 0;
+}
+
+static int reachable(struct commit *want)
+{
+	struct commit_list *work = NULL;
+
+	commit_list_insert_by_date(want, &work);
+	while (work) {
+		struct commit_list *list = work->next;
+		struct commit *commit = work->item;
+		free(work);
+		work = list;
+
+		if (commit->object.flags & THEY_HAVE) {
+			want->object.flags |= COMMON_KNOWN;
+			break;
+		}
+		if (!commit->object.parsed)
+			parse_object(commit->object.sha1);
+		if (commit->object.flags & REACHABLE)
+			continue;
+		commit->object.flags |= REACHABLE;
+		if (commit->date < oldest_have)
+			continue;
+		for (list = commit->parents; list; list = list->next) {
+			struct commit *parent = list->item;
+			if (!(parent->object.flags & REACHABLE))
+				commit_list_insert_by_date(parent, &work);
+		}
+	}
+	want->object.flags |= REACHABLE;
+	clear_commit_marks(want, REACHABLE);
+	free_commit_list(work);
+	return (want->object.flags & COMMON_KNOWN);
+}
+
+static int ok_to_give_up(void)
+{
+	int i;
+
+	if (!have_obj.nr)
+		return 0;
+
+	for (i = 0; i < want_obj.nr; i++) {
+		struct object *want = want_obj.objects[i].item;
+
+		if (want->flags & COMMON_KNOWN)
+			continue;
+		want = deref_tag(want, "a want line", 0);
+		if (!want || want->type != OBJ_COMMIT) {
+			/* no way to tell if this is reachable by
+			 * looking at the ancestry chain alone, so
+			 * leave a note to ourselves not to worry about
+			 * this object anymore.
+			 */
+			want_obj.objects[i].item->flags |= COMMON_KNOWN;
+			continue;
+		}
+		if (!reachable((struct commit *)want))
+			return 0;
+	}
 	return 1;
 }
 
 static int get_common_commits(void)
 {
-	static char line[1000];
-	unsigned char sha1[20], last_sha1[20];
-	int len;
+	unsigned char sha1[20];
+	char last_hex[41];
+	int got_common = 0;
+	int got_other = 0;
+	int sent_ready = 0;
 
-	track_object_refs = 0;
 	save_commit_buffer = 0;
 
-	for(;;) {
-		len = packet_read_line(0, line, sizeof(line));
+	for (;;) {
+		char *line = packet_read_line(0, NULL);
 		reset_timeout();
 
-		if (!len) {
+		if (!line) {
+			if (multi_ack == 2 && got_common
+			    && !got_other && ok_to_give_up()) {
+				sent_ready = 1;
+				packet_write(1, "ACK %s ready\n", last_hex);
+			}
 			if (have_obj.nr == 0 || multi_ack)
 				packet_write(1, "NAK\n");
+
+			if (no_done && sent_ready) {
+				packet_write(1, "ACK %s\n", last_hex);
+				return 0;
+			}
+			if (stateless_rpc)
+				exit(0);
+			got_common = 0;
+			got_other = 0;
 			continue;
 		}
-		len = strip(line, len);
-		if (!strncmp(line, "have ", 5)) {
-			if (got_sha1(line+5, sha1) &&
-			    (multi_ack || have_obj.nr == 1)) {
-				packet_write(1, "ACK %s%s\n",
-					     sha1_to_hex(sha1),
-					     multi_ack ?  " continue" : "");
-				if (multi_ack)
-					memcpy(last_sha1, sha1, 20);
+		if (!prefixcmp(line, "have ")) {
+			switch (got_sha1(line+5, sha1)) {
+			case -1: /* they have what we do not */
+				got_other = 1;
+				if (multi_ack && ok_to_give_up()) {
+					const char *hex = sha1_to_hex(sha1);
+					if (multi_ack == 2) {
+						sent_ready = 1;
+						packet_write(1, "ACK %s ready\n", hex);
+					} else
+						packet_write(1, "ACK %s continue\n", hex);
+				}
+				break;
+			default:
+				got_common = 1;
+				memcpy(last_hex, sha1_to_hex(sha1), 41);
+				if (multi_ack == 2)
+					packet_write(1, "ACK %s common\n", last_hex);
+				else if (multi_ack)
+					packet_write(1, "ACK %s continue\n", last_hex);
+				else if (have_obj.nr == 1)
+					packet_write(1, "ACK %s\n", last_hex);
+				break;
 			}
 			continue;
 		}
 		if (!strcmp(line, "done")) {
 			if (have_obj.nr > 0) {
 				if (multi_ack)
-					packet_write(1, "ACK %s\n",
-							sha1_to_hex(last_sha1));
+					packet_write(1, "ACK %s\n", last_hex);
 				return 0;
 			}
 			packet_write(1, "NAK\n");
 			return -1;
 		}
-		die("git-upload-pack: expected SHA1 list, got '%s'", line);
+		die("git upload-pack: expected SHA1 list, got '%s'", line);
+	}
+}
+
+static int is_our_ref(struct object *o)
+{
+	return o->flags &
+		((allow_tip_sha1_in_want ? HIDDEN_REF : 0) | OUR_REF);
+}
+
+static void check_non_tip(void)
+{
+	static const char *argv[] = {
+		"rev-list", "--stdin", NULL,
+	};
+	static struct child_process cmd;
+	struct object *o;
+	char namebuf[42]; /* ^ + SHA-1 + LF */
+	int i;
+
+	/* In the normal in-process case non-tip request can never happen */
+	if (!stateless_rpc)
+		goto error;
+
+	cmd.argv = argv;
+	cmd.git_cmd = 1;
+	cmd.no_stderr = 1;
+	cmd.in = -1;
+	cmd.out = -1;
+
+	if (start_command(&cmd))
+		goto error;
+
+	/*
+	 * If rev-list --stdin encounters an unknown commit, it
+	 * terminates, which will cause SIGPIPE in the write loop
+	 * below.
+	 */
+	sigchain_push(SIGPIPE, SIG_IGN);
+
+	namebuf[0] = '^';
+	namebuf[41] = '\n';
+	for (i = get_max_object_index(); 0 < i; ) {
+		o = get_indexed_object(--i);
+		if (!o)
+			continue;
+		if (!is_our_ref(o))
+			continue;
+		memcpy(namebuf + 1, sha1_to_hex(o->sha1), 40);
+		if (write_in_full(cmd.in, namebuf, 42) < 0)
+			goto error;
+	}
+	namebuf[40] = '\n';
+	for (i = 0; i < want_obj.nr; i++) {
+		o = want_obj.objects[i].item;
+		if (is_our_ref(o))
+			continue;
+		memcpy(namebuf, sha1_to_hex(o->sha1), 40);
+		if (write_in_full(cmd.in, namebuf, 41) < 0)
+			goto error;
+	}
+	close(cmd.in);
+
+	sigchain_pop(SIGPIPE);
+
+	/*
+	 * The commits out of the rev-list are not ancestors of
+	 * our ref.
+	 */
+	i = read_in_full(cmd.out, namebuf, 1);
+	if (i)
+		goto error;
+	close(cmd.out);
+
+	/*
+	 * rev-list may have died by encountering a bad commit
+	 * in the history, in which case we do want to bail out
+	 * even when it showed no commit.
+	 */
+	if (finish_command(&cmd))
+		goto error;
+
+	/* All the non-tip ones are ancestors of what we advertised */
+	return;
+
+error:
+	/* Pick one of them (we know there at least is one) */
+	for (i = 0; i < want_obj.nr; i++) {
+		o = want_obj.objects[i].item;
+		if (!is_our_ref(o))
+			die("git upload-pack: not our ref %s",
+			    sha1_to_hex(o->sha1));
 	}
 }
 
 static void receive_needs(void)
 {
-	static char line[1000];
-	int len;
+	struct object_array shallows = OBJECT_ARRAY_INIT;
+	int depth = 0;
+	int has_non_tip = 0;
 
+	shallow_nr = 0;
 	for (;;) {
 		struct object *o;
+		const char *features;
 		unsigned char sha1_buf[20];
-		len = packet_read_line(0, line, sizeof(line));
+		char *line = packet_read_line(0, NULL);
 		reset_timeout();
-		if (!len)
-			return;
+		if (!line)
+			break;
 
-		if (strncmp("want ", line, 5) ||
+		if (!prefixcmp(line, "shallow ")) {
+			unsigned char sha1[20];
+			struct object *object;
+			if (get_sha1_hex(line + 8, sha1))
+				die("invalid shallow line: %s", line);
+			object = parse_object(sha1);
+			if (!object)
+				continue;
+			if (object->type != OBJ_COMMIT)
+				die("invalid shallow object %s", sha1_to_hex(sha1));
+			if (!(object->flags & CLIENT_SHALLOW)) {
+				object->flags |= CLIENT_SHALLOW;
+				add_object_array(object, NULL, &shallows);
+			}
+			continue;
+		}
+		if (!prefixcmp(line, "deepen ")) {
+			char *end;
+			depth = strtol(line + 7, &end, 0);
+			if (end == line + 7 || depth <= 0)
+				die("Invalid deepen: %s", line);
+			continue;
+		}
+		if (prefixcmp(line, "want ") ||
 		    get_sha1_hex(line+5, sha1_buf))
-			die("git-upload-pack: protocol error, "
+			die("git upload-pack: protocol error, "
 			    "expected to get sha, not '%s'", line);
-		if (strstr(line+45, "multi_ack"))
+
+		features = line + 45;
+
+		if (parse_feature_request(features, "multi_ack_detailed"))
+			multi_ack = 2;
+		else if (parse_feature_request(features, "multi_ack"))
 			multi_ack = 1;
-		if (strstr(line+45, "thin-pack"))
+		if (parse_feature_request(features, "no-done"))
+			no_done = 1;
+		if (parse_feature_request(features, "thin-pack"))
 			use_thin_pack = 1;
-		if (strstr(line+45, "side-band"))
-			use_sideband = 1;
-
-		/* We have sent all our refs already, and the other end
-		 * should have chosen out of them; otherwise they are
-		 * asking for nonsense.
-		 *
-		 * Hmph.  We may later want to allow "want" line that
-		 * asks for something like "master~10" (symbolic)...
-		 * would it make sense?  I don't know.
-		 */
-		o = lookup_object(sha1_buf);
-		if (!o || !(o->flags & OUR_REF))
-			die("git-upload-pack: not our ref %s", line+5);
+		if (parse_feature_request(features, "ofs-delta"))
+			use_ofs_delta = 1;
+		if (parse_feature_request(features, "side-band-64k"))
+			use_sideband = LARGE_PACKET_MAX;
+		else if (parse_feature_request(features, "side-band"))
+			use_sideband = DEFAULT_PACKET_MAX;
+		if (parse_feature_request(features, "no-progress"))
+			no_progress = 1;
+		if (parse_feature_request(features, "include-tag"))
+			use_include_tag = 1;
+
+		o = parse_object(sha1_buf);
+		if (!o)
+			die("git upload-pack: not our ref %s",
+			    sha1_to_hex(sha1_buf));
 		if (!(o->flags & WANTED)) {
 			o->flags |= WANTED;
+			if (!is_our_ref(o))
+				has_non_tip = 1;
 			add_object_array(o, NULL, &want_obj);
 		}
 	}
+
+	/*
+	 * We have sent all our refs already, and the other end
+	 * should have chosen out of them. When we are operating
+	 * in the stateless RPC mode, however, their choice may
+	 * have been based on the set of older refs advertised
+	 * by another process that handled the initial request.
+	 */
+	if (has_non_tip)
+		check_non_tip();
+
+	if (!use_sideband && daemon_mode)
+		no_progress = 1;
+
+	if (depth == 0 && shallows.nr == 0)
+		return;
+	if (depth > 0) {
+		struct commit_list *result = NULL, *backup = NULL;
+		int i;
+		if (depth == INFINITE_DEPTH)
+			for (i = 0; i < shallows.nr; i++) {
+				struct object *object = shallows.objects[i].item;
+				object->flags |= NOT_SHALLOW;
+			}
+		else
+			backup = result =
+				get_shallow_commits(&want_obj, depth,
+						    SHALLOW, NOT_SHALLOW);
+		while (result) {
+			struct object *object = &result->item->object;
+			if (!(object->flags & (CLIENT_SHALLOW|NOT_SHALLOW))) {
+				packet_write(1, "shallow %s",
+						sha1_to_hex(object->sha1));
+				register_shallow(object->sha1);
+				shallow_nr++;
+			}
+			result = result->next;
+		}
+		free_commit_list(backup);
+		for (i = 0; i < shallows.nr; i++) {
+			struct object *object = shallows.objects[i].item;
+			if (object->flags & NOT_SHALLOW) {
+				struct commit_list *parents;
+				packet_write(1, "unshallow %s",
+					sha1_to_hex(object->sha1));
+				object->flags &= ~CLIENT_SHALLOW;
+				/* make sure the real parents are parsed */
+				unregister_shallow(object->sha1);
+				object->parsed = 0;
+				if (parse_commit((struct commit *)object))
+					die("invalid commit");
+				parents = ((struct commit *)object)->parents;
+				while (parents) {
+					add_object_array(&parents->item->object,
+							NULL, &want_obj);
+					parents = parents->next;
+				}
+				add_object_array(object, NULL, &extra_edge_obj);
+			}
+			/* make sure commit traversal conforms to client */
+			register_shallow(object->sha1);
+		}
+		packet_flush(1);
+	} else
+		if (shallows.nr > 0) {
+			int i;
+			for (i = 0; i < shallows.nr; i++)
+				register_shallow(shallows.objects[i].item->sha1);
+		}
+
+	shallow_nr += shallows.nr;
+	free(shallows.objects);
 }
 
-static int send_ref(const char *refname, const unsigned char *sha1)
+/* return non-zero if the ref is hidden, otherwise 0 */
+static int mark_our_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
 {
-	static const char *capabilities = "multi_ack thin-pack side-band";
-	struct object *o = parse_object(sha1);
+	struct object *o = lookup_unknown_object(sha1);
 
+	if (ref_is_hidden(refname)) {
+		o->flags |= HIDDEN_REF;
+		return 1;
+	}
 	if (!o)
-		die("git-upload-pack: cannot find object %s:", sha1_to_hex(sha1));
+		die("git upload-pack: cannot find object %s:", sha1_to_hex(sha1));
+	o->flags |= OUR_REF;
+	return 0;
+}
 
-	if (capabilities)
-		packet_write(1, "%s %s%c%s\n", sha1_to_hex(sha1), refname,
-			0, capabilities);
-	else
-		packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname);
-	capabilities = NULL;
-	if (!(o->flags & OUR_REF)) {
-		o->flags |= OUR_REF;
-		nr_our_refs++;
-	}
-	if (o->type == OBJ_TAG) {
-		o = deref_tag(o, refname, 0);
-		packet_write(1, "%s %s^{}\n", sha1_to_hex(o->sha1), refname);
+static void format_symref_info(struct strbuf *buf, struct string_list *symref)
+{
+	struct string_list_item *item;
+
+	if (!symref->nr)
+		return;
+	for_each_string_list_item(item, symref)
+		strbuf_addf(buf, " symref=%s:%s", item->string, (char *)item->util);
+}
+
+static int send_ref(const char *refname, const unsigned char *sha1, int flag, void *cb_data)
+{
+	static const char *capabilities = "multi_ack thin-pack side-band"
+		" side-band-64k ofs-delta shallow no-progress"
+		" include-tag multi_ack_detailed";
+	const char *refname_nons = strip_namespace(refname);
+	unsigned char peeled[20];
+
+	if (mark_our_ref(refname, sha1, flag, NULL))
+		return 0;
+
+	if (capabilities) {
+		struct strbuf symref_info = STRBUF_INIT;
+
+		format_symref_info(&symref_info, cb_data);
+		packet_write(1, "%s %s%c%s%s%s%s agent=%s\n",
+			     sha1_to_hex(sha1), refname_nons,
+			     0, capabilities,
+			     allow_tip_sha1_in_want ? " allow-tip-sha1-in-want" : "",
+			     stateless_rpc ? " no-done" : "",
+			     symref_info.buf,
+			     git_user_agent_sanitized());
+		strbuf_release(&symref_info);
+	} else {
+		packet_write(1, "%s %s\n", sha1_to_hex(sha1), refname_nons);
 	}
+	capabilities = NULL;
+	if (!peel_ref(refname, peeled))
+		packet_write(1, "%s %s^{}\n", sha1_to_hex(peeled), refname_nons);
+	return 0;
+}
+
+static int find_symref(const char *refname, const unsigned char *sha1, int flag,
+		       void *cb_data)
+{
+	const char *symref_target;
+	struct string_list_item *item;
+	unsigned char unused[20];
+
+	if ((flag & REF_ISSYMREF) == 0)
+		return 0;
+	symref_target = resolve_ref_unsafe(refname, unused, 0, &flag);
+	if (!symref_target || (flag & REF_ISSYMREF) == 0)
+		die("'%s' is a symref but it is not?", refname);
+	item = string_list_append(cb_data, refname);
+	item->util = xstrdup(symref_target);
 	return 0;
 }
 
 static void upload_pack(void)
 {
-	reset_timeout();
-	head_ref(send_ref);
-	for_each_ref(send_ref);
-	packet_flush(1);
+	struct string_list symref = STRING_LIST_INIT_DUP;
+
+	head_ref_namespaced(find_symref, &symref);
+	for_each_namespaced_ref(find_symref, &symref);
+
+	if (advertise_refs || !stateless_rpc) {
+		reset_timeout();
+		head_ref_namespaced(send_ref, &symref);
+		for_each_namespaced_ref(send_ref, &symref);
+		packet_flush(1);
+	} else {
+		head_ref_namespaced(mark_our_ref, NULL);
+		for_each_namespaced_ref(mark_our_ref, NULL);
+	}
+	string_list_clear(&symref, 1);
+	if (advertise_refs)
+		return;
+
 	receive_needs();
 	if (want_obj.nr) {
 		get_common_commits();
@@ -472,23 +775,50 @@ static void upload_pack(void)
 	}
 }
 
+static int upload_pack_config(const char *var, const char *value, void *unused)
+{
+	if (!strcmp("uploadpack.allowtipsha1inwant", var))
+		allow_tip_sha1_in_want = git_config_bool(var, value);
+	else if (!strcmp("uploadpack.keepalive", var)) {
+		keepalive = git_config_int(var, value);
+		if (!keepalive)
+			keepalive = -1;
+	}
+	return parse_hide_refs_config(var, value, "uploadpack");
+}
+
 int main(int argc, char **argv)
 {
 	char *dir;
 	int i;
 	int strict = 0;
 
+	git_setup_gettext();
+
+	packet_trace_identity("upload-pack");
+	git_extract_argv0_path(argv[0]);
+	read_replace_refs = 0;
+
 	for (i = 1; i < argc; i++) {
 		char *arg = argv[i];
 
 		if (arg[0] != '-')
 			break;
+		if (!strcmp(arg, "--advertise-refs")) {
+			advertise_refs = 1;
+			continue;
+		}
+		if (!strcmp(arg, "--stateless-rpc")) {
+			stateless_rpc = 1;
+			continue;
+		}
 		if (!strcmp(arg, "--strict")) {
 			strict = 1;
 			continue;
 		}
-		if (!strncmp(arg, "--timeout=", 10)) {
+		if (!prefixcmp(arg, "--timeout=")) {
 			timeout = atoi(arg+10);
+			daemon_mode = 1;
 			continue;
 		}
 		if (!strcmp(arg, "--")) {
@@ -496,14 +826,19 @@ int main(int argc, char **argv)
 			break;
 		}
 	}
-	
+
 	if (i != argc-1)
 		usage(upload_pack_usage);
+
+	setup_path();
+
 	dir = argv[i];
 
 	if (!enter_repo(dir, strict))
-		die("'%s': unable to chdir or not a git archive", dir);
-
+		die("'%s' does not appear to be a git repository", dir);
+	if (is_repository_shallow())
+		die("attempt to fetch/clone from a shallow repository");
+	git_config(upload_pack_config, NULL);
 	upload_pack();
 	return 0;
 }