Merge branch 'np/index-pack'

* np/index-pack:
  remove .keep pack lock files when done with refs update
  have index-pack create .keep file more carefully
  improve fetch-pack's handling of kept packs
  git-fetch can use both --thin and --keep with fetch-pack now
  Teach receive-pack how to keep pack files based on object count.
  Allow pack header preprocessing before unpack-objects/index-pack.
  Remove unused variable in receive-pack.
  Revert "send-pack --keep: do not explode into loose objects on the receiving end."
  missing small substitution
  Teach git-index-pack how to keep a pack file.
  Only repack active packs by skipping over kept packs.
  Allow short pack names to git-pack-objects --unpacked=.
  send-pack --keep: do not explode into loose objects on the receiving end.
  index-pack: minor fixes to comment and function name
  enhance clone and fetch -k experience
  mimic unpack-objects when --stdin is used with index-pack
  add progress status to index-pack
  make index-pack able to complete thin packs.
  enable index-pack streaming capability

13 files changed, 824 insertions, 411 deletions

diff --git a/Documentation/config.txt b/Documentation/config.txt
index d9e73da2a..9d3c71c3b 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -301,7 +301,16 @@ imap::
 	The configuration variables in the 'imap' section are described
 	in gitlink:git-imap-send[1].
 
-receive.denyNonFastforwads::
+receive.unpackLimit::
+	If the number of objects received in a push is below this
+	limit then the objects will be unpacked into loose object
+	files. However if the number of received objects equals or
+	exceeds this limit then the received pack will be stored as
+	a pack, after adding any missing delta bases.  Storing the
+	pack from a push can make the push operation complete faster,
+	especially on slow filesystems.
+
+receive.denyNonFastForwards::
 	If set to true, git-receive-pack will deny a ref update which is
 	not a fast forward. Use this to prevent such an update via a push,
 	even if that push is forced. This configuration variable is
diff --git a/Documentation/git-fetch-pack.txt b/Documentation/git-fetch-pack.txt
index bff9aa693..3e6cd880b 100644
--- a/Documentation/git-fetch-pack.txt
+++ b/Documentation/git-fetch-pack.txt
@@ -32,7 +32,8 @@ OPTIONS
 -k::
 	Do not invoke 'git-unpack-objects' on received data, but
 	create a single packfile out of it instead, and store it
-	in the object database.
+	in the object database. If provided twice then the pack is
+	locked against repacking.
 
 --exec=<git-upload-pack>::
 	Use this to specify the path to 'git-upload-pack' on the
diff --git a/Documentation/git-index-pack.txt b/Documentation/git-index-pack.txt
index 71ce55727..2229ee86b 100644
--- a/Documentation/git-index-pack.txt
+++ b/Documentation/git-index-pack.txt
@@ -8,7 +8,8 @@ git-index-pack - Build pack index file for an existing packed archive
 
 SYNOPSIS
 --------
-'git-index-pack' [-o <index-file>] <pack-file>
+'git-index-pack' [-v] [-o <index-file>] <pack-file>
+'git-index-pack' --stdin [--fix-thin] [--keep] [-v] [-o <index-file>] [<pack-file>]
 
 
 DESCRIPTION
@@ -21,6 +22,9 @@ objects/pack/ directory of a git repository.
 
 OPTIONS
 -------
+-v::
+	Be verbose about what is going on, including progress status.
+
 -o <index-file>::
 	Write the generated pack index into the specified
 	file.  Without this option the name of pack index
@@ -29,6 +33,52 @@ OPTIONS
 	fails if the name of packed archive does not end
 	with .pack).
 
+--stdin::
+	When this flag is provided, the pack is read from stdin
+	instead and a copy is then written to <pack-file>. If
+	<pack-file> is not specified, the pack is written to
+	objects/pack/ directory of the current git repository with
+	a default name determined from the pack content.  If
+	<pack-file> is not specified consider using --keep to
+	prevent a race condition between this process and
+	gitlink::git-repack[1] .
+
+--fix-thin::
+	It is possible for gitlink:git-pack-objects[1] to build
+	"thin" pack, which records objects in deltified form based on
+	objects not included in the pack to reduce network traffic.
+	Those objects are expected to be present on the receiving end
+	and they must be included in the pack for that pack to be self
+	contained and indexable. Without this option any attempt to
+	index a thin pack will fail. This option only makes sense in
+	conjunction with --stdin.
+
+--keep::
+	Before moving the index into its final destination
+	create an empty .keep file for the associated pack file.
+	This option is usually necessary with --stdin to prevent a
+	simultaneous gitlink:git-repack[1] process from deleting
+	the newly constructed pack and index before refs can be
+	updated to use objects contained in the pack.
+
+--keep='why'::
+	Like --keep create a .keep file before moving the index into
+	its final destination, but rather than creating an empty file
+	place 'why' followed by an LF into the .keep file.  The 'why'
+	message can later be searched for within all .keep files to
+	locate any which have outlived their usefulness.
+
+
+Note
+----
+
+Once the index has been created, the list of object names is sorted
+and the SHA1 hash of that list is printed to stdout. If --stdin was
+also used then this is prefixed by either "pack\t", or "keep\t" if a
+new .keep file was successfully created. This is useful to remove a
+.keep file used as a lock to prevent the race with gitlink:git-repack[1]
+mentioned above.
+
 
 Author
 ------
diff --git a/Makefile b/Makefile
index 2af4eb31c..6d324fb56 100644
--- a/Makefile
+++ b/Makefile
@@ -257,7 +257,7 @@ LIB_OBJS = \
 	quote.o read-cache.o refs.o run-command.o dir.o object-refs.o \
 	server-info.o setup.o sha1_file.o sha1_name.o strbuf.o \
 	tag.o tree.o usage.o config.o environment.o ctype.o copy.o \
-	fetch-clone.o revision.o pager.o tree-walk.o xdiff-interface.o \
+	revision.o pager.o tree-walk.o xdiff-interface.o \
 	write_or_die.o trace.o list-objects.o grep.o \
 	alloc.o merge-file.o path-list.o help.o unpack-trees.o $(DIFF_OBJS) \
 	color.o wt-status.o archive-zip.o archive-tar.o
diff --git a/builtin-unpack-objects.c b/builtin-unpack-objects.c
index 74a90c112..e6d757484 100644
--- a/builtin-unpack-objects.c
+++ b/builtin-unpack-objects.c
@@ -371,6 +371,21 @@ int cmd_unpack_objects(int argc, const char **argv, const char *prefix)
 				recover = 1;
 				continue;
 			}
+			if (!strncmp(arg, "--pack_header=", 14)) {
+				struct pack_header *hdr;
+				char *c;
+
+				hdr = (struct pack_header *)buffer;
+				hdr->hdr_signature = htonl(PACK_SIGNATURE);
+				hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
+				if (*c != ',')
+					die("bad %s", arg);
+				hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
+				if (*c)
+					die("bad %s", arg);
+				len = sizeof(*hdr);
+				continue;
+			}
 			usage(unpack_usage);
 		}
 
diff --git a/cache.h b/cache.h
index e997a8500..f2ec5c8c1 100644
--- a/cache.h
+++ b/cache.h
@@ -376,6 +376,7 @@ extern struct packed_git *parse_pack_index_file(const unsigned char *sha1,
 						char *idx_path);
 
 extern void prepare_packed_git(void);
+extern void reprepare_packed_git(void);
 extern void install_packed_git(struct packed_git *pack);
 
 extern struct packed_git *find_sha1_pack(const unsigned char *sha1, 
@@ -415,10 +416,6 @@ extern int copy_fd(int ifd, int ofd);
 extern void write_or_die(int fd, const void *buf, size_t count);
 extern int write_or_whine(int fd, const void *buf, size_t count, const char *msg);
 
-/* Finish off pack transfer receiving end */
-extern int receive_unpack_pack(int fd[2], const char *me, int quiet, int);
-extern int receive_keep_pack(int fd[2], const char *me, int quiet, int);
-
 /* pager.c */
 extern void setup_pager(void);
 extern int pager_in_use;
diff --git a/fetch-clone.c b/fetch-clone.c
deleted file mode 100644
index 76b99afcd..000000000
--- a/fetch-clone.c
+++ /dev/null
@@ -1,276 +0,0 @@
-#include "cache.h"
-#include "exec_cmd.h"
-#include "pkt-line.h"
-#include "sideband.h"
-#include <sys/wait.h>
-#include <sys/time.h>
-
-static int finish_pack(const char *pack_tmp_name, const char *me)
-{
-	int pipe_fd[2];
-	pid_t pid;
-	char idx[PATH_MAX];
-	char final[PATH_MAX];
-	char hash[41];
-	unsigned char sha1[20];
-	char *cp;
-	int err = 0;
-
-	if (pipe(pipe_fd) < 0)
-		die("%s: unable to set up pipe", me);
-
-	strcpy(idx, pack_tmp_name); /* ".git/objects/pack-XXXXXX" */
-	cp = strrchr(idx, '/');
-	memcpy(cp, "/pidx", 5);
-
-	pid = fork();
-	if (pid < 0)
-		die("%s: unable to fork off git-index-pack", me);
-	if (!pid) {
-		close(0);
-		dup2(pipe_fd[1], 1);
-		close(pipe_fd[0]);
-		close(pipe_fd[1]);
-		execl_git_cmd("index-pack", "-o", idx, pack_tmp_name, NULL);
-		error("cannot exec git-index-pack <%s> <%s>",
-		      idx, pack_tmp_name);
-		exit(1);
-	}
-	close(pipe_fd[1]);
-	if (read(pipe_fd[0], hash, 40) != 40) {
-		error("%s: unable to read from git-index-pack", me);
-		err = 1;
-	}
-	close(pipe_fd[0]);
-
-	for (;;) {
-		int status, code;
-
-		if (waitpid(pid, &status, 0) < 0) {
-			if (errno == EINTR)
-				continue;
-			error("waitpid failed (%s)", strerror(errno));
-			goto error_die;
-		}
-		if (WIFSIGNALED(status)) {
-			int sig = WTERMSIG(status);
-			error("git-index-pack died of signal %d", sig);
-			goto error_die;
-		}
-		if (!WIFEXITED(status)) {
-			error("git-index-pack died of unnatural causes %d",
-			      status);
-			goto error_die;
-		}
-		code = WEXITSTATUS(status);
-		if (code) {
-			error("git-index-pack died with error code %d", code);
-			goto error_die;
-		}
-		if (err)
-			goto error_die;
-		break;
-	}
-	hash[40] = 0;
-	if (get_sha1_hex(hash, sha1)) {
-		error("git-index-pack reported nonsense '%s'", hash);
-		goto error_die;
-	}
-	/* Now we have pack in pack_tmp_name[], and
-	 * idx in idx[]; rename them to their final names.
-	 */
-	snprintf(final, sizeof(final),
-		 "%s/pack/pack-%s.pack", get_object_directory(), hash);
-	move_temp_to_file(pack_tmp_name, final);
-	chmod(final, 0444);
-	snprintf(final, sizeof(final),
-		 "%s/pack/pack-%s.idx", get_object_directory(), hash);
-	move_temp_to_file(idx, final);
-	chmod(final, 0444);
-	return 0;
-
- error_die:
-	unlink(idx);
-	unlink(pack_tmp_name);
-	exit(1);
-}
-
-static pid_t setup_sideband(int sideband, const char *me, int fd[2], int xd[2])
-{
-	pid_t side_pid;
-
-	if (!sideband) {
-		fd[0] = xd[0];
-		fd[1] = xd[1];
-		return 0;
-	}
-	/* xd[] is talking with upload-pack; subprocess reads from
-	 * xd[0], spits out band#2 to stderr, and feeds us band#1
-	 * through our fd[0].
-	 */
-	if (pipe(fd) < 0)
-		die("%s: unable to set up pipe", me);
-	side_pid = fork();
-	if (side_pid < 0)
-		die("%s: unable to fork off sideband demultiplexer", me);
-	if (!side_pid) {
-		/* subprocess */
-		close(fd[0]);
-		if (xd[0] != xd[1])
-			close(xd[1]);
-		if (recv_sideband(me, xd[0], fd[1], 2))
-			exit(1);
-		exit(0);
-	}
-	close(xd[0]);
-	close(fd[1]);
-	fd[1] = xd[1];
-	return side_pid;
-}
-
-int receive_unpack_pack(int xd[2], const char *me, int quiet, int sideband)
-{
-	int status;
-	pid_t pid, side_pid;
-	int fd[2];
-
-	side_pid = setup_sideband(sideband, me, fd, xd);
-	pid = fork();
-	if (pid < 0)
-		die("%s: unable to fork off git-unpack-objects", me);
-	if (!pid) {
-		dup2(fd[0], 0);
-		close(fd[0]);
-		close(fd[1]);
-		execl_git_cmd("unpack-objects", quiet ? "-q" : NULL, NULL);
-		die("git-unpack-objects exec failed");
-	}
-	close(fd[0]);
-	close(fd[1]);
-	while (waitpid(pid, &status, 0) < 0) {
-		if (errno != EINTR)
-			die("waiting for git-unpack-objects: %s",
-			    strerror(errno));
-	}
-	if (WIFEXITED(status)) {
-		int code = WEXITSTATUS(status);
-		if (code)
-			die("git-unpack-objects died with error code %d",
-			    code);
-		return 0;
-	}
-	if (WIFSIGNALED(status)) {
-		int sig = WTERMSIG(status);
-		die("git-unpack-objects died of signal %d", sig);
-	}
-	die("git-unpack-objects died of unnatural causes %d", status);
-}
-
-/*
- * We average out the download speed over this many "events", where
- * an event is a minimum of about half a second. That way, we get
- * a reasonably stable number.
- */
-#define NR_AVERAGE (4)
-
-/*
- * A "binary msec" is a power-of-two-msec, aka 1/1024th of a second.
- * Keeping the time in that format means that "bytes / msecs" means
- * the same as kB/s (modulo rounding).
- *
- * 1000512 is a magic number (usecs in a second, rounded up by half
- * of 1024, to make "rounding" come out right ;)
- */
-#define usec_to_binarymsec(x) ((int)(x) / (1000512 >> 10))
-
-int receive_keep_pack(int xd[2], const char *me, int quiet, int sideband)
-{
-	char tmpfile[PATH_MAX];
-	int ofd, ifd, fd[2];
-	unsigned long total;
-	static struct timeval prev_tv;
-	struct average {
-		unsigned long bytes;
-		unsigned long time;
-	} download[NR_AVERAGE] = { {0, 0}, };
-	unsigned long avg_bytes, avg_time;
-	int idx = 0;
-
-	setup_sideband(sideband, me, fd, xd);
-
-	ifd = fd[0];
-	snprintf(tmpfile, sizeof(tmpfile),
-		 "%s/pack/tmp-XXXXXX", get_object_directory());
-	ofd = mkstemp(tmpfile);
-	if (ofd < 0)
-		return error("unable to create temporary file %s", tmpfile);
-
-	gettimeofday(&prev_tv, NULL);
-	total = 0;
-	avg_bytes = 0;
-	avg_time = 0;
-	while (1) {
-		char buf[8192];
-		ssize_t sz, wsz, pos;
-		sz = read(ifd, buf, sizeof(buf));
-		if (sz == 0)
-			break;
-		if (sz < 0) {
-			if (errno != EINTR && errno != EAGAIN) {
-				error("error reading pack (%s)", strerror(errno));
-				close(ofd);
-				unlink(tmpfile);
-				return -1;
-			}
-			sz = 0;
-		}
-		pos = 0;
-		while (pos < sz) {
-			wsz = write(ofd, buf + pos, sz - pos);
-			if (wsz < 0) {
-				error("error writing pack (%s)",
-				      strerror(errno));
-				close(ofd);
-				unlink(tmpfile);
-				return -1;
-			}
-			pos += wsz;
-		}
-		total += sz;
-		if (!quiet) {
-			static unsigned long last;
-			struct timeval tv;
-			unsigned long diff = total - last;
-			/* not really "msecs", but a power-of-two millisec (1/1024th of a sec) */
-			unsigned long msecs;
-
-			gettimeofday(&tv, NULL);
-			msecs = tv.tv_sec - prev_tv.tv_sec;
-			msecs <<= 10;
-			msecs += usec_to_binarymsec(tv.tv_usec - prev_tv.tv_usec);
-
-			if (msecs > 500) {
-				prev_tv = tv;
-				last = total;
-
-				/* Update averages ..*/
-				avg_bytes += diff;
-				avg_time += msecs;
-				avg_bytes -= download[idx].bytes;
-				avg_time -= download[idx].time;
-				download[idx].bytes = diff;
-				download[idx].time = msecs;
-				idx++;
-				if (idx >= NR_AVERAGE)
-					idx = 0;
-
-				fprintf(stderr, "%4lu.%03luMB  (%lu kB/s)      \r",
-					total >> 20,
-					1000*((total >> 10) & 1023)>>10,
-					avg_bytes / avg_time );
-			}
-		}
-	}
-	close(ofd);
-	return finish_pack(tmpfile, me);
-}
diff --git a/fetch-pack.c b/fetch-pack.c
index 90b79407c..0a169dce8 100644
--- a/fetch-pack.c
+++ b/fetch-pack.c
@@ -3,6 +3,9 @@
 #include "pkt-line.h"
 #include "commit.h"
 #include "tag.h"
+#include "exec_cmd.h"
+#include "sideband.h"
+#include <sys/wait.h>
 
 static int keep_pack;
 static int quiet;
@@ -416,6 +419,103 @@ static int everything_local(struct ref **refs, int nr_match, char **match)
 	return retval;
 }
 
+static pid_t setup_sideband(int fd[2], int xd[2])
+{
+	pid_t side_pid;
+
+	if (!use_sideband) {
+		fd[0] = xd[0];
+		fd[1] = xd[1];
+		return 0;
+	}
+	/* xd[] is talking with upload-pack; subprocess reads from
+	 * xd[0], spits out band#2 to stderr, and feeds us band#1
+	 * through our fd[0].
+	 */
+	if (pipe(fd) < 0)
+		die("fetch-pack: unable to set up pipe");
+	side_pid = fork();
+	if (side_pid < 0)
+		die("fetch-pack: unable to fork off sideband demultiplexer");
+	if (!side_pid) {
+		/* subprocess */
+		close(fd[0]);
+		if (xd[0] != xd[1])
+			close(xd[1]);
+		if (recv_sideband("fetch-pack", xd[0], fd[1], 2))
+			exit(1);
+		exit(0);
+	}
+	close(xd[0]);
+	close(fd[1]);
+	fd[1] = xd[1];
+	return side_pid;
+}
+
+static int get_pack(int xd[2], const char **argv)
+{
+	int status;
+	pid_t pid, side_pid;
+	int fd[2];
+
+	side_pid = setup_sideband(fd, xd);
+	pid = fork();
+	if (pid < 0)
+		die("fetch-pack: unable to fork off %s", argv[0]);
+	if (!pid) {
+		dup2(fd[0], 0);
+		close(fd[0]);
+		close(fd[1]);
+		execv_git_cmd(argv);
+		die("%s exec failed", argv[0]);
+	}
+	close(fd[0]);
+	close(fd[1]);
+	while (waitpid(pid, &status, 0) < 0) {
+		if (errno != EINTR)
+			die("waiting for %s: %s", argv[0], strerror(errno));
+	}
+	if (WIFEXITED(status)) {
+		int code = WEXITSTATUS(status);
+		if (code)
+			die("%s died with error code %d", argv[0], code);
+		return 0;
+	}
+	if (WIFSIGNALED(status)) {
+		int sig = WTERMSIG(status);
+		die("%s died of signal %d", argv[0], sig);
+	}
+	die("%s died of unnatural causes %d", argv[0], status);
+}
+
+static int explode_rx_pack(int xd[2])
+{
+	const char *argv[3] = { "unpack-objects", quiet ? "-q" : NULL, NULL };
+	return get_pack(xd, argv);
+}
+
+static int keep_rx_pack(int xd[2])
+{
+	const char *argv[6];
+	char keep_arg[256];
+	int n = 0;
+
+	argv[n++] = "index-pack";
+	argv[n++] = "--stdin";
+	if (!quiet)
+		argv[n++] = "-v";
+	if (use_thin_pack)
+		argv[n++] = "--fix-thin";
+	if (keep_pack > 1) {
+		int s = sprintf(keep_arg, "--keep=fetch-pack %i on ", getpid());
+		if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
+			strcpy(keep_arg + s, "localhost");
+		argv[n++] = keep_arg;
+	}
+	argv[n] = NULL;
+	return get_pack(xd, argv);
+}
+
 static int fetch_pack(int fd[2], int nr_match, char **match)
 {
 	struct ref *ref;
@@ -447,17 +547,13 @@ static int fetch_pack(int fd[2], int nr_match, char **match)
 		goto all_done;
 	}
 	if (find_common(fd, sha1, ref) < 0)
-		if (!keep_pack)
+		if (keep_pack != 1)
 			/* When cloning, it is not unusual to have
 			 * no common commit.
 			 */
 			fprintf(stderr, "warning: no common commits\n");
 
-	if (keep_pack)
-		status = receive_keep_pack(fd, "git-fetch-pack", quiet, use_sideband);
-	else
-		status = receive_unpack_pack(fd, "git-fetch-pack", quiet, use_sideband);
-
+	status = (keep_pack) ? keep_rx_pack(fd) : explode_rx_pack(fd);
 	if (status)
 		die("git-fetch-pack: fetch failed.");
 
@@ -494,7 +590,7 @@ int main(int argc, char **argv)
 				continue;
 			}
 			if (!strcmp("--keep", arg) || !strcmp("-k", arg)) {
-				keep_pack = 1;
+				keep_pack++;
 				continue;
 			}
 			if (!strcmp("--thin", arg)) {
@@ -518,8 +614,6 @@ int main(int argc, char **argv)
 	}
 	if (!dest)
 		usage(fetch_pack_usage);
-	if (keep_pack)
-		use_thin_pack = 0;
 	pid = git_connect(fd, dest, exec);
 	if (pid < 0)
 		return 1;
diff --git a/git-fetch.sh b/git-fetch.sh
index 539dff6ee..7442dd2ca 100755
--- a/git-fetch.sh
+++ b/git-fetch.sh
@@ -20,7 +20,7 @@ verbose=
 update_head_ok=
 exec=
 upload_pack=
-keep=--thin
+keep=
 while case "$#" in 0) break ;; esac
 do
 	case "$1" in
@@ -51,7 +51,7 @@ do
 		verbose=Yes
 		;;
 	-k|--k|--ke|--kee|--keep)
-		keep=--keep
+		keep='-k -k'
 		;;
 	--reflog-action=*)
 		rloga=`expr "z$1" : 'z-[^=]*=\(.*\)'`
@@ -368,9 +368,10 @@ fetch_main () {
       ;; # we are already done.
   *)
     ( : subshell because we muck with IFS
+      pack_lockfile=
       IFS=" 	$LF"
       (
-	  git-fetch-pack $exec $keep "$remote" $rref || echo failed "$remote"
+	  git-fetch-pack --thin $exec $keep "$remote" $rref || echo failed "$remote"
       ) |
       while read sha1 remote_name
       do
@@ -378,6 +379,12 @@ fetch_main () {
 	  failed)
 		  echo >&2 "Fetch failure: $remote"
 		  exit 1 ;;
+	  # special line coming from index-pack with the pack name
+	  pack)
+		  continue ;;
+	  keep)
+		  pack_lockfile="$GIT_OBJECT_DIRECTORY/pack/pack-$remote_name.keep"
+		  continue ;;
 	  esac
 	  found=
 	  single_force=
@@ -408,6 +415,7 @@ fetch_main () {
 	  append_fetch_head "$sha1" "$remote" \
 		  "$remote_name" "$remote_nick" "$local_name" "$not_for_merge"
       done
+      if [ "$pack_lockfile" ]; then rm -f "$pack_lockfile"; fi
     ) || exit ;;
   esac
 
diff --git a/git-repack.sh b/git-repack.sh
index 17e24526c..f150a558c 100755
--- a/git-repack.sh
+++ b/git-repack.sh
@@ -45,11 +45,19 @@ case ",$all_into_one," in
 	args='--unpacked --incremental'
 	;;
 ,t,)
-	args=
-
-	# Redundancy check in all-into-one case is trivial.
-	existing=`test -d "$PACKDIR" && cd "$PACKDIR" && \
-	    find . -type f \( -name '*.pack' -o -name '*.idx' \) -print`
+	if [ -d "$PACKDIR" ]; then
+		for e in `cd "$PACKDIR" && find . -type f -name '*.pack' \
+			| sed -e 's/^\.\///' -e 's/\.pack$//'`
+		do
+			if [ -e "$PACKDIR/$e.keep" ]; then
+				: keep
+			else
+				args="$args --unpacked=$e.pack"
+				existing="$existing $e"
+			fi
+		done
+	fi
+	[ -z "$args" ] && args='--unpacked --incremental'
 	;;
 esac
 
@@ -86,17 +94,16 @@ fi
 
 if test "$remove_redundant" = t
 then
-	# We know $existing are all redundant only when
-	# all-into-one is used.
-	if test "$all_into_one" != '' && test "$existing" != ''
+	# We know $existing are all redundant.
+	if [ -n "$existing" ]
 	then
 		sync
 		( cd "$PACKDIR" &&
 		  for e in $existing
 		  do
 			case "$e" in
-			./pack-$name.pack | ./pack-$name.idx) ;;
-			*)	rm -f $e ;;
+			pack-$name) ;;
+			*)	rm -f "$e.pack" "$e.idx" "$e.keep" ;;
 			esac
 		  done
 		)
diff --git a/index-pack.c b/index-pack.c
index 70640e14d..042aea884 100644
--- a/index-pack.c
+++ b/index-pack.c
@@ -6,9 +6,11 @@
 #include "commit.h"
 #include "tag.h"
 #include "tree.h"
+#include <sys/time.h>
+#include <signal.h>
 
 static const char index_pack_usage[] =
-"git-index-pack [-o index-file] pack-file";
+"git-index-pack [-v] [-o <index-file>] [{ ---keep | --keep=<msg> }] { <pack-file> | --stdin [--fix-thin] [<pack-file>] }";
 
 struct object_entry
 {
@@ -33,21 +35,71 @@ union delta_base {
 
 struct delta_entry
 {
-	struct object_entry *obj;
 	union delta_base base;
+	int obj_no;
 };
 
-static const char *pack_name;
 static struct object_entry *objects;
 static struct delta_entry *deltas;
 static int nr_objects;
 static int nr_deltas;
+static int nr_resolved_deltas;
+
+static int from_stdin;
+static int verbose;
+
+static volatile sig_atomic_t progress_update;
+
+static void progress_interval(int signum)
+{
+	progress_update = 1;
+}
+
+static void setup_progress_signal(void)
+{
+	struct sigaction sa;
+	struct itimerval v;
+
+	memset(&sa, 0, sizeof(sa));
+	sa.sa_handler = progress_interval;
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = SA_RESTART;
+	sigaction(SIGALRM, &sa, NULL);
+
+	v.it_interval.tv_sec = 1;
+	v.it_interval.tv_usec = 0;
+	v.it_value = v.it_interval;
+	setitimer(ITIMER_REAL, &v, NULL);
+
+}
+
+static unsigned display_progress(unsigned n, unsigned total, unsigned last_pc)
+{
+	unsigned percent = n * 100 / total;
+	if (percent != last_pc || progress_update) {
+		fprintf(stderr, "%4u%% (%u/%u) done\r", percent, n, total);
+		progress_update = 0;
+	}
+	return percent;
+}
 
 /* We always read in 4kB chunks. */
 static unsigned char input_buffer[4096];
 static unsigned long input_offset, input_len, consumed_bytes;
 static SHA_CTX input_ctx;
-static int input_fd;
+static int input_fd, output_fd, mmap_fd;
+
+/* Discard current buffer used content. */
+static void flush()
+{
+	if (input_offset) {
+		if (output_fd >= 0)
+			write_or_die(output_fd, input_buffer, input_offset);
+		SHA1_Update(&input_ctx, input_buffer, input_offset);
+		memcpy(input_buffer, input_buffer + input_offset, input_len);
+		input_offset = 0;
+	}
+}
 
 /*
  * Make sure at least "min" bytes are available in the buffer, and
@@ -59,11 +111,7 @@ static void *fill(int min)
 		return input_buffer + input_offset;
 	if (min > sizeof(input_buffer))
 		die("cannot fill %d bytes", min);
-	if (input_offset) {
-		SHA1_Update(&input_ctx, input_buffer, input_offset);
-		memmove(input_buffer, input_buffer + input_offset, input_len);
-		input_offset = 0;
-	}
+	flush();
 	do {
 		int ret = xread(input_fd, input_buffer + input_len,
 				sizeof(input_buffer) - input_len);
@@ -86,13 +134,31 @@ static void use(int bytes)
 	consumed_bytes += bytes;
 }
 
-static void open_pack_file(void)
+static const char *open_pack_file(const char *pack_name)
 {
-	input_fd = open(pack_name, O_RDONLY);
-	if (input_fd < 0)
-		die("cannot open packfile '%s': %s", pack_name,
-		    strerror(errno));
+	if (from_stdin) {
+		input_fd = 0;
+		if (!pack_name) {
+			static char tmpfile[PATH_MAX];
+			snprintf(tmpfile, sizeof(tmpfile),
+				 "%s/pack_XXXXXX", get_object_directory());
+			output_fd = mkstemp(tmpfile);
+			pack_name = xstrdup(tmpfile);
+		} else
+			output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
+		if (output_fd < 0)
+			die("unable to create %s: %s\n", pack_name, strerror(errno));
+		mmap_fd = output_fd;
+	} else {
+		input_fd = open(pack_name, O_RDONLY);
+		if (input_fd < 0)
+			die("cannot open packfile '%s': %s",
+			    pack_name, strerror(errno));
+		output_fd = -1;
+		mmap_fd = input_fd;
+	}
 	SHA1_Init(&input_ctx);
+	return pack_name;
 }
 
 static void parse_pack_header(void)
@@ -101,14 +167,12 @@ static void parse_pack_header(void)
 
 	/* Header consistency check */
 	if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
-		die("packfile '%s' signature mismatch", pack_name);
+		die("pack signature mismatch");
 	if (!pack_version_ok(hdr->hdr_version))
-		die("packfile '%s' version %d unsupported",
-		    pack_name, ntohl(hdr->hdr_version));
+		die("pack version %d unsupported", ntohl(hdr->hdr_version));
 
 	nr_objects = ntohl(hdr->hdr_entries);
 	use(sizeof(struct pack_header));
-	/*fprintf(stderr, "Indexing %d objects\n", nr_objects);*/
 }
 
 static void bad_object(unsigned long offset, const char *format,
@@ -122,8 +186,7 @@ static void bad_object(unsigned long offset, const char *format, ...)
 	va_start(params, format);
 	vsnprintf(buf, sizeof(buf), format, params);
 	va_end(params);
-	die("packfile '%s': bad object at offset %lu: %s",
-	    pack_name, offset, buf);
+	die("pack has bad object at offset %lu: %s", offset, buf);
 }
 
 static void *unpack_entry_data(unsigned long offset, unsigned long size)
@@ -212,7 +275,7 @@ static void *unpack_raw_entry(struct object_entry *obj, union delta_base *delta_
 	return unpack_entry_data(obj->offset, obj->size);
 }
 
-static void * get_data_from_pack(struct object_entry *obj)
+static void *get_data_from_pack(struct object_entry *obj)
 {
 	unsigned long from = obj[0].offset + obj[0].hdr_size;
 	unsigned long len = obj[1].offset - from;
@@ -222,9 +285,9 @@ static void * get_data_from_pack(struct object_entry *obj)
 	int st;
 
 	map = mmap(NULL, len + pg_offset, PROT_READ, MAP_PRIVATE,
-		   input_fd, from - pg_offset);
+		   mmap_fd, from - pg_offset);
 	if (map == MAP_FAILED)
-		die("cannot mmap packfile '%s': %s", pack_name, strerror(errno));
+		die("cannot mmap pack file: %s", strerror(errno));
 	data = xmalloc(obj->size);
 	memset(&stream, 0, sizeof(stream));
 	stream.next_out = data;
@@ -261,8 +324,8 @@ static int find_delta(const union delta_base *base)
         return -first-1;
 }
 
-static int find_delta_childs(const union delta_base *base,
-			     int *first_index, int *last_index)
+static int find_delta_children(const union delta_base *base,
+			       int *first_index, int *last_index)
 {
 	int first = find_delta(base);
 	int last = first;
@@ -304,10 +367,9 @@ static void sha1_object(const void *data, unsigned long size,
 	SHA1_Final(sha1, &ctx);
 }
 
-static void resolve_delta(struct delta_entry *delta, void *base_data,
+static void resolve_delta(struct object_entry *delta_obj, void *base_data,
 			  unsigned long base_size, enum object_type type)
 {
-	struct object_entry *obj = delta->obj;
 	void *delta_data;
 	unsigned long delta_size;
 	void *result;
@@ -315,29 +377,34 @@ static void resolve_delta(struct delta_entry *delta, void *base_data,
 	union delta_base delta_base;
 	int j, first, last;
 
-	obj->real_type = type;
-	delta_data = get_data_from_pack(obj);
-	delta_size = obj->size;
+	delta_obj->real_type = type;
+	delta_data = get_data_from_pack(delta_obj);
+	delta_size = delta_obj->size;
 	result = patch_delta(base_data, base_size, delta_data, delta_size,
 			     &result_size);
 	free(delta_data);
 	if (!result)
-		bad_object(obj->offset, "failed to apply delta");
-	sha1_object(result, result_size, type, obj->sha1);
-
-	hashcpy(delta_base.sha1, obj->sha1);
-	if (!find_delta_childs(&delta_base, &first, &last)) {
-		for (j = first; j <= last; j++)
-			if (deltas[j].obj->type == OBJ_REF_DELTA)
-				resolve_delta(&deltas[j], result, result_size, type);
+		bad_object(delta_obj->offset, "failed to apply delta");
+	sha1_object(result, result_size, type, delta_obj->sha1);
+	nr_resolved_deltas++;
+
+	hashcpy(delta_base.sha1, delta_obj->sha1);
+	if (!find_delta_children(&delta_base, &first, &last)) {
+		for (j = first; j <= last; j++) {
+			struct object_entry *child = objects + deltas[j].obj_no;
+			if (child->real_type == OBJ_REF_DELTA)
+				resolve_delta(child, result, result_size, type);
+		}
 	}
 
 	memset(&delta_base, 0, sizeof(delta_base));
-	delta_base.offset = obj->offset;
-	if (!find_delta_childs(&delta_base, &first, &last)) {
-		for (j = first; j <= last; j++)
-			if (deltas[j].obj->type == OBJ_OFS_DELTA)
-				resolve_delta(&deltas[j], result, result_size, type);
+	delta_base.offset = delta_obj->offset;
+	if (!find_delta_children(&delta_base, &first, &last)) {
+		for (j = first; j <= last; j++) {
+			struct object_entry *child = objects + deltas[j].obj_no;
+			if (child->real_type == OBJ_OFS_DELTA)
+				resolve_delta(child, result, result_size, type);
+		}
 	}
 
 	free(result);
@@ -353,7 +420,7 @@ static int compare_delta_entry(const void *a, const void *b)
 /* Parse all objects and return the pack content SHA1 hash */
 static void parse_pack_objects(unsigned char *sha1)
 {
-	int i;
+	int i, percent = -1;
 	struct delta_entry *delta = deltas;
 	void *data;
 	struct stat st;
@@ -362,34 +429,43 @@ static void parse_pack_objects(unsigned char *sha1)
 	 * First pass:
 	 * - find locations of all objects;
 	 * - calculate SHA1 of all non-delta objects;
-	 * - remember base SHA1 for all deltas.
+	 * - remember base (SHA1 or offset) for all deltas.
 	 */
+	if (verbose)
+		fprintf(stderr, "Indexing %d objects.\n", nr_objects);
 	for (i = 0; i < nr_objects; i++) {
 		struct object_entry *obj = &objects[i];
 		data = unpack_raw_entry(obj, &delta->base);
 		obj->real_type = obj->type;
 		if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA) {
 			nr_deltas++;
-			delta->obj = obj;
+			delta->obj_no = i;
 			delta++;
 		} else
 			sha1_object(data, obj->size, obj->type, obj->sha1);
 		free(data);
+		if (verbose)
+			percent = display_progress(i+1, nr_objects, percent);
 	}
 	objects[i].offset = consumed_bytes;
+	if (verbose)
+		fputc('\n', stderr);
 
 	/* Check pack integrity */
-	SHA1_Update(&input_ctx, input_buffer, input_offset);
+	flush();
 	SHA1_Final(sha1, &input_ctx);
 	if (hashcmp(fill(20), sha1))
-		die("packfile '%s' SHA1 mismatch", pack_name);
+		die("pack is corrupted (SHA1 mismatch)");
 	use(20);
 
 	/* If input_fd is a file, we should have reached its end now. */
 	if (fstat(input_fd, &st))
-		die("cannot fstat packfile '%s': %s", pack_name, strerror(errno));
+		die("cannot fstat packfile: %s", strerror(errno));
 	if (S_ISREG(st.st_mode) && st.st_size != consumed_bytes)
-		die("packfile '%s' has junk at the end", pack_name);
+		die("pack has junk at the end");
+
+	if (!nr_deltas)
+		return;
 
 	/* Sort deltas by base SHA1/offset for fast searching */
 	qsort(deltas, nr_deltas, sizeof(struct delta_entry),
@@ -403,6 +479,8 @@ static void parse_pack_objects(unsigned char *sha1)
 	 *   recursively checking if the resulting object is used as a base
 	 *   for some more deltas.
 	 */
+	if (verbose)
+		fprintf(stderr, "Resolving %d deltas.\n", nr_deltas);
 	for (i = 0; i < nr_objects; i++) {
 		struct object_entry *obj = &objects[i];
 		union delta_base base;
@@ -411,32 +489,179 @@ static void parse_pack_objects(unsigned char *sha1)
 		if (obj->type == OBJ_REF_DELTA || obj->type == OBJ_OFS_DELTA)
 			continue;
 		hashcpy(base.sha1, obj->sha1);
-		ref = !find_delta_childs(&base, &ref_first, &ref_last);
+		ref = !find_delta_children(&base, &ref_first, &ref_last);
 		memset(&base, 0, sizeof(base));
 		base.offset = obj->offset;
-		ofs = !find_delta_childs(&base, &ofs_first, &ofs_last);
+		ofs = !find_delta_children(&base, &ofs_first, &ofs_last);
 		if (!ref && !ofs)
 			continue;
 		data = get_data_from_pack(obj);
 		if (ref)
-			for (j = ref_first; j <= ref_last; j++)
-				if (deltas[j].obj->type == OBJ_REF_DELTA)
-					resolve_delta(&deltas[j], data,
+			for (j = ref_first; j <= ref_last; j++) {
+				struct object_entry *child = objects + deltas[j].obj_no;
+				if (child->real_type == OBJ_REF_DELTA)
+					resolve_delta(child, data,
 						      obj->size, obj->type);
+			}
 		if (ofs)
-			for (j = ofs_first; j <= ofs_last; j++)
-				if (deltas[j].obj->type == OBJ_OFS_DELTA)
-					resolve_delta(&deltas[j], data,
+			for (j = ofs_first; j <= ofs_last; j++) {
+				struct object_entry *child = objects + deltas[j].obj_no;
+				if (child->real_type == OBJ_OFS_DELTA)
+					resolve_delta(child, data,
 						      obj->size, obj->type);
+			}
 		free(data);
+		if (verbose)
+			percent = display_progress(nr_resolved_deltas,
+						   nr_deltas, percent);
 	}
+	if (verbose && nr_resolved_deltas == nr_deltas)
+		fputc('\n', stderr);
+}
+
+static int write_compressed(int fd, void *in, unsigned int size)
+{
+	z_stream stream;
+	unsigned long maxsize;
+	void *out;
+
+	memset(&stream, 0, sizeof(stream));
+	deflateInit(&stream, zlib_compression_level);
+	maxsize = deflateBound(&stream, size);
+	out = xmalloc(maxsize);
+
+	/* Compress it */
+	stream.next_in = in;
+	stream.avail_in = size;
+	stream.next_out = out;
+	stream.avail_out = maxsize;
+	while (deflate(&stream, Z_FINISH) == Z_OK);
+	deflateEnd(&stream);
+
+	size = stream.total_out;
+	write_or_die(fd, out, size);
+	free(out);
+	return size;
+}
+
+static void append_obj_to_pack(void *buf,
+			       unsigned long size, enum object_type type)
+{
+	struct object_entry *obj = &objects[nr_objects++];
+	unsigned char header[10];
+	unsigned long s = size;
+	int n = 0;
+	unsigned char c = (type << 4) | (s & 15);
+	s >>= 4;
+	while (s) {
+		header[n++] = c | 0x80;
+		c = s & 0x7f;
+		s >>= 7;
+	}
+	header[n++] = c;
+	write_or_die(output_fd, header, n);
+	obj[1].offset = obj[0].offset + n;
+	obj[1].offset += write_compressed(output_fd, buf, size);
+	sha1_object(buf, size, type, obj->sha1);
+}
+
+static int delta_pos_compare(const void *_a, const void *_b)
+{
+	struct delta_entry *a = *(struct delta_entry **)_a;
+	struct delta_entry *b = *(struct delta_entry **)_b;
+	return a->obj_no - b->obj_no;
+}
+
+static void fix_unresolved_deltas(int nr_unresolved)
+{
+	struct delta_entry **sorted_by_pos;
+	int i, n = 0, percent = -1;
 
-	/* Check for unresolved deltas */
+	/*
+	 * Since many unresolved deltas may well be themselves base objects
+	 * for more unresolved deltas, we really want to include the
+	 * smallest number of base objects that would cover as much delta
+	 * as possible by picking the
+	 * trunc deltas first, allowing for other deltas to resolve without
+	 * additional base objects.  Since most base objects are to be found
+	 * before deltas depending on them, a good heuristic is to start
+	 * resolving deltas in the same order as their position in the pack.
+	 */
+	sorted_by_pos = xmalloc(nr_unresolved * sizeof(*sorted_by_pos));
 	for (i = 0; i < nr_deltas; i++) {
-		if (deltas[i].obj->real_type == OBJ_REF_DELTA ||
-		    deltas[i].obj->real_type == OBJ_OFS_DELTA)
-			die("packfile '%s' has unresolved deltas",  pack_name);
+		if (objects[deltas[i].obj_no].real_type != OBJ_REF_DELTA)
+			continue;
+		sorted_by_pos[n++] = &deltas[i];
+	}
+	qsort(sorted_by_pos, n, sizeof(*sorted_by_pos), delta_pos_compare);
+
+	for (i = 0; i < n; i++) {
+		struct delta_entry *d = sorted_by_pos[i];
+		void *data;
+		unsigned long size;
+		char type[10];
+		enum object_type obj_type;
+		int j, first, last;
+
+		if (objects[d->obj_no].real_type != OBJ_REF_DELTA)
+			continue;
+		data = read_sha1_file(d->base.sha1, type, &size);
+		if (!data)
+			continue;
+		if      (!strcmp(type, blob_type))   obj_type = OBJ_BLOB;
+		else if (!strcmp(type, tree_type))   obj_type = OBJ_TREE;
+		else if (!strcmp(type, commit_type)) obj_type = OBJ_COMMIT;
+		else if (!strcmp(type, tag_type))    obj_type = OBJ_TAG;
+		else die("base object %s is of type '%s'",
+			 sha1_to_hex(d->base.sha1), type);
+
+		find_delta_children(&d->base, &first, &last);
+		for (j = first; j <= last; j++) {
+			struct object_entry *child = objects + deltas[j].obj_no;
+			if (child->real_type == OBJ_REF_DELTA)
+				resolve_delta(child, data, size, obj_type);
+		}
+
+		append_obj_to_pack(data, size, obj_type);
+		free(data);
+		if (verbose)
+			percent = display_progress(nr_resolved_deltas,
+						   nr_deltas, percent);
 	}
+	free(sorted_by_pos);
+	if (verbose)
+		fputc('\n', stderr);
+}
+
+static void readjust_pack_header_and_sha1(unsigned char *sha1)
+{
+	struct pack_header hdr;
+	SHA_CTX ctx;
+	int size;
+
+	/* Rewrite pack header with updated object number */
+	if (lseek(output_fd, 0, SEEK_SET) != 0)
+		die("cannot seek back: %s", strerror(errno));
+	if (xread(output_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
+		die("cannot read pack header back: %s", strerror(errno));
+	hdr.hdr_entries = htonl(nr_objects);
+	if (lseek(output_fd, 0, SEEK_SET) != 0)
+		die("cannot seek back: %s", strerror(errno));
+	write_or_die(output_fd, &hdr, sizeof(hdr));
+	if (lseek(output_fd, 0, SEEK_SET) != 0)
+		die("cannot seek back: %s", strerror(errno));
+
+	/* Recompute and store the new pack's SHA1 */
+	SHA1_Init(&ctx);
+	do {
+		unsigned char *buf[4096];
+		size = xread(output_fd, buf, sizeof(buf));
+		if (size < 0)
+			die("cannot read pack data back: %s", strerror(errno));
+		SHA1_Update(&ctx, buf, size);
+	} while (size > 0);
+	SHA1_Final(sha1, &ctx);
+	write_or_die(output_fd, sha1, 20);
 }
 
 static int sha1_compare(const void *_a, const void *_b)
@@ -450,12 +675,12 @@ static int sha1_compare(const void *_a, const void *_b)
  * On entry *sha1 contains the pack content SHA1 hash, on exit it is
  * the SHA1 hash of sorted object names.
  */
-static void write_index_file(const char *index_name, unsigned char *sha1)
+static const char *write_index_file(const char *index_name, unsigned char *sha1)
 {
 	struct sha1file *f;
 	struct object_entry **sorted_by_sha, **list, **last;
 	unsigned int array[256];
-	int i;
+	int i, fd;
 	SHA_CTX ctx;
 
 	if (nr_objects) {
@@ -472,8 +697,19 @@ static void write_index_file(const char *index_name, unsigned char *sha1)
 	else
 		sorted_by_sha = list = last = NULL;
 
-	unlink(index_name);
-	f = sha1create("%s", index_name);
+	if (!index_name) {
+		static char tmpfile[PATH_MAX];
+		snprintf(tmpfile, sizeof(tmpfile),
+			 "%s/index_XXXXXX", get_object_directory());
+		fd = mkstemp(tmpfile);
+		index_name = xstrdup(tmpfile);
+	} else {
+		unlink(index_name);
+		fd = open(index_name, O_CREAT|O_EXCL|O_WRONLY, 0600);
+	}
+	if (fd < 0)
+		die("unable to create %s: %s", index_name, strerror(errno));
+	f = sha1fd(fd, index_name);
 
 	/*
 	 * Write the first-level table (the list is sorted,
@@ -513,20 +749,128 @@ static void write_index_file(const char *index_name, unsigned char *sha1)
 	sha1close(f, NULL, 1);
 	free(sorted_by_sha);
 	SHA1_Final(sha1, &ctx);
+	return index_name;
+}
+
+static void final(const char *final_pack_name, const char *curr_pack_name,
+		  const char *final_index_name, const char *curr_index_name,
+		  const char *keep_name, const char *keep_msg,
+		  unsigned char *sha1)
+{
+	char *report = "pack";
+	char name[PATH_MAX];
+	int err;
+
+	if (!from_stdin) {
+		close(input_fd);
+	} else {
+		err = close(output_fd);
+		if (err)
+			die("error while closing pack file: %s", strerror(errno));
+		chmod(curr_pack_name, 0444);
+	}
+
+	if (keep_msg) {
+		int keep_fd, keep_msg_len = strlen(keep_msg);
+		if (!keep_name) {
+			snprintf(name, sizeof(name), "%s/pack/pack-%s.keep",
+				 get_object_directory(), sha1_to_hex(sha1));
+			keep_name = name;
+		}
+		keep_fd = open(keep_name, O_RDWR|O_CREAT|O_EXCL, 0600);
+		if (keep_fd < 0) {
+			if (errno != EEXIST)
+				die("cannot write keep file");
+		} else {
+			if (keep_msg_len > 0) {
+				write_or_die(keep_fd, keep_msg, keep_msg_len);
+				write_or_die(keep_fd, "\n", 1);
+			}
+			close(keep_fd);
+			report = "keep";
+		}
+	}
+
+	if (final_pack_name != curr_pack_name) {
+		if (!final_pack_name) {
+			snprintf(name, sizeof(name), "%s/pack/pack-%s.pack",
+				 get_object_directory(), sha1_to_hex(sha1));
+			final_pack_name = name;
+		}
+		if (move_temp_to_file(curr_pack_name, final_pack_name))
+			die("cannot store pack file");
+	}
+
+	chmod(curr_index_name, 0444);
+	if (final_index_name != curr_index_name) {
+		if (!final_index_name) {
+			snprintf(name, sizeof(name), "%s/pack/pack-%s.idx",
+				 get_object_directory(), sha1_to_hex(sha1));
+			final_index_name = name;
+		}
+		if (move_temp_to_file(curr_index_name, final_index_name))
+			die("cannot store index file");
+	}
+
+	if (!from_stdin) {
+		printf("%s\n", sha1_to_hex(sha1));
+	} else {
+		char buf[48];
+		int len = snprintf(buf, sizeof(buf), "%s\t%s\n",
+				   report, sha1_to_hex(sha1));
+		xwrite(1, buf, len);
+
+		/*
+		 * Let's just mimic git-unpack-objects here and write
+		 * the last part of the input buffer to stdout.
+		 */
+		while (input_len) {
+			err = xwrite(1, input_buffer + input_offset, input_len);
+			if (err <= 0)
+				break;
+			input_len -= err;
+			input_offset += err;
+		}
+	}
 }
 
 int main(int argc, char **argv)
 {
-	int i;
-	char *index_name = NULL;
-	char *index_name_buf = NULL;
+	int i, fix_thin_pack = 0;
+	const char *curr_pack, *pack_name = NULL;
+	const char *curr_index, *index_name = NULL;
+	const char *keep_name = NULL, *keep_msg = NULL;
+	char *index_name_buf = NULL, *keep_name_buf = NULL;
 	unsigned char sha1[20];
 
 	for (i = 1; i < argc; i++) {
 		const char *arg = argv[i];
 
 		if (*arg == '-') {
-			if (!strcmp(arg, "-o")) {
+			if (!strcmp(arg, "--stdin")) {
+				from_stdin = 1;
+			} else if (!strcmp(arg, "--fix-thin")) {
+				fix_thin_pack = 1;
+			} else if (!strcmp(arg, "--keep")) {
+				keep_msg = "";
+			} else if (!strncmp(arg, "--keep=", 7)) {
+				keep_msg = arg + 7;
+			} else if (!strncmp(arg, "--pack_header=", 14)) {
+				struct pack_header *hdr;
+				char *c;
+
+				hdr = (struct pack_header *)input_buffer;
+				hdr->hdr_signature = htonl(PACK_SIGNATURE);
+				hdr->hdr_version = htonl(strtoul(arg + 14, &c, 10));
+				if (*c != ',')
+					die("bad %s", arg);
+				hdr->hdr_entries = htonl(strtoul(c + 1, &c, 10));
+				if (*c)
+					die("bad %s", arg);
+				input_len = sizeof(*hdr);
+			} else if (!strcmp(arg, "-v")) {
+				verbose = 1;
+			} else if (!strcmp(arg, "-o")) {
 				if (index_name || (i+1) >= argc)
 					usage(index_pack_usage);
 				index_name = argv[++i];
@@ -540,9 +884,11 @@ int main(int argc, char **argv)
 		pack_name = arg;
 	}
 
-	if (!pack_name)
+	if (!pack_name && !from_stdin)
 		usage(index_pack_usage);
-	if (!index_name) {
+	if (fix_thin_pack && !from_stdin)
+		die("--fix-thin cannot be used without --stdin");
+	if (!index_name && pack_name) {
 		int len = strlen(pack_name);
 		if (!has_extension(pack_name, ".pack"))
 			die("packfile name '%s' does not end with '.pack'",
@@ -552,18 +898,55 @@ int main(int argc, char **argv)
 		strcpy(index_name_buf + len - 5, ".idx");
 		index_name = index_name_buf;
 	}
+	if (keep_msg && !keep_name && pack_name) {
+		int len = strlen(pack_name);
+		if (!has_extension(pack_name, ".pack"))
+			die("packfile name '%s' does not end with '.pack'",
+			    pack_name);
+		keep_name_buf = xmalloc(len);
+		memcpy(keep_name_buf, pack_name, len - 5);
+		strcpy(keep_name_buf + len - 5, ".keep");
+		keep_name = keep_name_buf;
+	}
 
-	open_pack_file();
+	curr_pack = open_pack_file(pack_name);
 	parse_pack_header();
-	objects = xcalloc(nr_objects + 1, sizeof(struct object_entry));
-	deltas = xcalloc(nr_objects, sizeof(struct delta_entry));
+	objects = xmalloc((nr_objects + 1) * sizeof(struct object_entry));
+	deltas = xmalloc(nr_objects * sizeof(struct delta_entry));
+	if (verbose)
+		setup_progress_signal();
 	parse_pack_objects(sha1);
+	if (nr_deltas != nr_resolved_deltas) {
+		if (fix_thin_pack) {
+			int nr_unresolved = nr_deltas - nr_resolved_deltas;
+			int nr_objects_initial = nr_objects;
+			if (nr_unresolved <= 0)
+				die("confusion beyond insanity");
+			objects = xrealloc(objects,
+					   (nr_objects + nr_unresolved + 1)
+					   * sizeof(*objects));
+			fix_unresolved_deltas(nr_unresolved);
+			if (verbose)
+				fprintf(stderr, "%d objects were added to complete this thin pack.\n",
+					nr_objects - nr_objects_initial);
+			readjust_pack_header_and_sha1(sha1);
+		}
+		if (nr_deltas != nr_resolved_deltas)
+			die("pack has %d unresolved deltas",
+			    nr_deltas - nr_resolved_deltas);
+	} else {
+		/* Flush remaining pack final 20-byte SHA1. */
+		flush();
+	}
 	free(deltas);
-	write_index_file(index_name, sha1);
+	curr_index = write_index_file(index_name, sha1);
+	final(pack_name, curr_pack,
+		index_name, curr_index,
+		keep_name, keep_msg,
+		sha1);
 	free(objects);
 	free(index_name_buf);
-
-	printf("%s\n", sha1_to_hex(sha1));
+	free(keep_name_buf);
 
 	return 0;
 }
diff --git a/receive-pack.c b/receive-pack.c
index de1d6a4b1..d56898c9b 100644
--- a/receive-pack.c
+++ b/receive-pack.c
@@ -1,15 +1,17 @@
 #include "cache.h"
+#include "pack.h"
 #include "refs.h"
 #include "pkt-line.h"
 #include "run-command.h"
+#include "exec_cmd.h"
 #include "commit.h"
 #include "object.h"
+#include <sys/wait.h>
 
 static const char receive_pack_usage[] = "git-receive-pack <git-dir>";
 
-static const char *unpacker[] = { "unpack-objects", NULL };
-
 static int deny_non_fast_forwards = 0;
+static int unpack_limit = 5000;
 static int report_status;
 
 static char capabilities[] = "report-status";
@@ -25,6 +27,12 @@ static int receive_pack_config(const char *var, const char *value)
 		return 0;
 	}
 
+	if (strcmp(var, "receive.unpacklimit") == 0)
+	{
+		unpack_limit = git_config_int(var, value);
+		return 0;
+	}
+
 	return 0;
 }
 
@@ -227,29 +235,127 @@ static void read_head_info(void)
 	}
 }
 
-static const char *unpack(int *error_code)
+static const char *parse_pack_header(struct pack_header *hdr)
 {
-	int code = run_command_v_opt(1, unpacker, RUN_GIT_CMD);
+	char *c = (char*)hdr;
+	ssize_t remaining = sizeof(struct pack_header);
+	do {
+		ssize_t r = xread(0, c, remaining);
+		if (r <= 0)
+			return "eof before pack header was fully read";
+		remaining -= r;
+		c += r;
+	} while (remaining > 0);
+	if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
+		return "protocol error (pack signature mismatch detected)";
+	if (!pack_version_ok(hdr->hdr_version))
+		return "protocol error (pack version unsupported)";
+	return NULL;
+}
 
-	*error_code = 0;
-	switch (code) {
-	case 0:
-		return NULL;
-	case -ERR_RUN_COMMAND_FORK:
-		return "unpack fork failed";
-	case -ERR_RUN_COMMAND_EXEC:
-		return "unpack execute failed";
-	case -ERR_RUN_COMMAND_WAITPID:
-		return "waitpid failed";
-	case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
-		return "waitpid is confused";
-	case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
-		return "unpacker died of signal";
-	case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
-		return "unpacker died strangely";
-	default:
-		*error_code = -code;
-		return "unpacker exited with error code";
+static const char *pack_lockfile;
+
+static const char *unpack(void)
+{
+	struct pack_header hdr;
+	const char *hdr_err;
+	char hdr_arg[38];
+
+	hdr_err = parse_pack_header(&hdr);
+	if (hdr_err)
+		return hdr_err;
+	snprintf(hdr_arg, sizeof(hdr_arg), "--pack_header=%u,%u",
+			ntohl(hdr.hdr_version), ntohl(hdr.hdr_entries));
+
+	if (ntohl(hdr.hdr_entries) < unpack_limit) {
+		int code;
+		const char *unpacker[3];
+		unpacker[0] = "unpack-objects";
+		unpacker[1] = hdr_arg;
+		unpacker[2] = NULL;
+		code = run_command_v_opt(1, unpacker, RUN_GIT_CMD);
+		switch (code) {
+		case 0:
+			return NULL;
+		case -ERR_RUN_COMMAND_FORK:
+			return "unpack fork failed";
+		case -ERR_RUN_COMMAND_EXEC:
+			return "unpack execute failed";
+		case -ERR_RUN_COMMAND_WAITPID:
+			return "waitpid failed";
+		case -ERR_RUN_COMMAND_WAITPID_WRONG_PID:
+			return "waitpid is confused";
+		case -ERR_RUN_COMMAND_WAITPID_SIGNAL:
+			return "unpacker died of signal";
+		case -ERR_RUN_COMMAND_WAITPID_NOEXIT:
+			return "unpacker died strangely";
+		default:
+			return "unpacker exited with error code";
+		}
+	} else {
+		const char *keeper[6];
+		int fd[2], s, len, status;
+		pid_t pid;
+		char keep_arg[256];
+		char packname[46];
+
+		s = sprintf(keep_arg, "--keep=receive-pack %i on ", getpid());
+		if (gethostname(keep_arg + s, sizeof(keep_arg) - s))
+			strcpy(keep_arg + s, "localhost");
+
+		keeper[0] = "index-pack";
+		keeper[1] = "--stdin";
+		keeper[2] = "--fix-thin";
+		keeper[3] = hdr_arg;
+		keeper[4] = keep_arg;
+		keeper[5] = NULL;
+
+		if (pipe(fd) < 0)
+			return "index-pack pipe failed";
+		pid = fork();
+		if (pid < 0)
+			return "index-pack fork failed";
+		if (!pid) {
+			dup2(fd[1], 1);
+			close(fd[1]);
+			close(fd[0]);
+			execv_git_cmd(keeper);
+			die("execv of index-pack failed");
+		}
+		close(fd[1]);
+
+		/*
+		 * The first thing we expects from index-pack's output
+		 * is "pack\t%40s\n" or "keep\t%40s\n" (46 bytes) where
+		 * %40s is the newly created pack SHA1 name.  In the "keep"
+		 * case, we need it to remove the corresponding .keep file
+		 * later on.  If we don't get that then tough luck with it.
+		 */
+		for (len = 0;
+		     len < 46 && (s = xread(fd[0], packname+len, 46-len)) > 0;
+		     len += s);
+		close(fd[0]);
+		if (len == 46 && packname[45] == '\n' &&
+		    memcmp(packname, "keep\t", 5) == 0) {
+			char path[PATH_MAX];
+			packname[45] = 0;
+			snprintf(path, sizeof(path), "%s/pack/pack-%s.keep",
+				 get_object_directory(), packname + 5);
+			pack_lockfile = xstrdup(path);
+		}
+
+		/* Then wrap our index-pack process. */
+		while (waitpid(pid, &status, 0) < 0)
+			if (errno != EINTR)
+				return "waitpid failed";
+		if (WIFEXITED(status)) {
+			int code = WEXITSTATUS(status);
+			if (code)
+				return "index-pack exited with error code";
+			reprepare_packed_git();
+			return NULL;
+		}
+		return "index-pack abnormal exit";
 	}
 }
 
@@ -302,10 +408,11 @@ int main(int argc, char **argv)
 
 	read_head_info();
 	if (commands) {
-		int code;
-		const char *unpack_status = unpack(&code);
+		const char *unpack_status = unpack();
 		if (!unpack_status)
 			execute_commands();
+		if (pack_lockfile)
+			unlink(pack_lockfile);
 		if (report_status)
 			report(unpack_status);
 	}
diff --git a/sha1_file.c b/sha1_file.c
index 4e5ee1054..6ea59b558 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -663,7 +663,7 @@ void prepare_packed_git(void)
 	prepare_packed_git_run_once = 1;
 }
 
-static void reprepare_packed_git(void)
+void reprepare_packed_git(void)
 {
 	prepare_packed_git_run_once = 0;
 	prepare_packed_git();
@@ -1203,6 +1203,24 @@ unsigned long find_pack_entry_one(const unsigned char *sha1,
 	return 0;
 }
 
+static int matches_pack_name(struct packed_git *p, const char *ig)
+{
+	const char *last_c, *c;
+
+	if (!strcmp(p->pack_name, ig))
+		return 0;
+
+	for (c = p->pack_name, last_c = c; *c;)
+		if (*c == '/')
+			last_c = ++c;
+		else
+			++c;
+	if (!strcmp(last_c, ig))
+		return 0;
+
+	return 1;
+}
+
 static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, const char **ignore_packed)
 {
 	struct packed_git *p;
@@ -1214,7 +1232,7 @@ static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e, cons
 		if (ignore_packed) {
 			const char **ig;
 			for (ig = ignore_packed; *ig; ig++)
-				if (!strcmp(p->pack_name, *ig))
+				if (!matches_pack_name(p, *ig))
 					break;
 			if (*ig)
 				continue;