1 files changed, 1008 insertions, 214 deletions

diff --git a/builtin/repack.c b/builtin/repack.c
index 5f9bc74..15e4ccc 100644
--- a/builtin/repack.c
+++ b/builtin/repack.c
@@ -1,25 +1,40 @@
 #include "builtin.h"
-#include "cache.h"
 #include "config.h"
 #include "dir.h"
+#include "environment.h"
+#include "gettext.h"
+#include "hex.h"
 #include "parse-options.h"
+#include "path.h"
 #include "run-command.h"
-#include "sigchain.h"
+#include "server-info.h"
 #include "strbuf.h"
 #include "string-list.h"
 #include "strvec.h"
 #include "midx.h"
 #include "packfile.h"
 #include "prune-packed.h"
-#include "object-store.h"
+#include "object-store-ll.h"
 #include "promisor-remote.h"
 #include "shallow.h"
 #include "pack.h"
+#include "pack-bitmap.h"
+#include "refs.h"
+#include "list-objects-filter-options.h"
 
+#define ALL_INTO_ONE 1
+#define LOOSEN_UNREACHABLE 2
+#define PACK_CRUFT 4
+
+#define DELETE_PACK 1
+#define RETAIN_PACK 2
+
+static int pack_everything;
 static int delta_base_offset = 1;
 static int pack_kept_objects = -1;
 static int write_bitmaps = -1;
 static int use_delta_islands;
+static int run_update_server_info = 1;
 static char *packdir, *packtmp_name, *packtmp;
 
 static const char *const git_repack_usage[] = {
@@ -29,12 +44,26 @@ static const char *const git_repack_usage[] = {
 
 static const char incremental_bitmap_conflict_error[] = N_(
 "Incremental repacks are incompatible with bitmap indexes.  Use\n"
-"--no-write-bitmap-index or disable the pack.writebitmaps configuration."
+"--no-write-bitmap-index or disable the pack.writeBitmaps configuration."
 );
 
+struct pack_objects_args {
+	const char *window;
+	const char *window_memory;
+	const char *depth;
+	const char *threads;
+	unsigned long max_pack_size;
+	int no_reuse_delta;
+	int no_reuse_object;
+	int quiet;
+	int local;
+	struct list_objects_filter_options filter_options;
+};
 
-static int repack_config(const char *var, const char *value, void *cb)
+static int repack_config(const char *var, const char *value,
+			 const struct config_context *ctx, void *cb)
 {
+	struct pack_objects_args *cruft_po_args = cb;
 	if (!strcmp(var, "repack.usedeltabaseoffset")) {
 		delta_base_offset = git_config_bool(var, value);
 		return 0;
@@ -52,83 +81,114 @@ static int repack_config(const char *var, const char *value, void *cb)
 		use_delta_islands = git_config_bool(var, value);
 		return 0;
 	}
-	return git_default_config(var, value, cb);
+	if (strcmp(var, "repack.updateserverinfo") == 0) {
+		run_update_server_info = git_config_bool(var, value);
+		return 0;
+	}
+	if (!strcmp(var, "repack.cruftwindow"))
+		return git_config_string(&cruft_po_args->window, var, value);
+	if (!strcmp(var, "repack.cruftwindowmemory"))
+		return git_config_string(&cruft_po_args->window_memory, var, value);
+	if (!strcmp(var, "repack.cruftdepth"))
+		return git_config_string(&cruft_po_args->depth, var, value);
+	if (!strcmp(var, "repack.cruftthreads"))
+		return git_config_string(&cruft_po_args->threads, var, value);
+	return git_default_config(var, value, ctx, cb);
 }
 
-/*
- * Remove temporary $GIT_OBJECT_DIRECTORY/pack/.tmp-$$-pack-* files.
- */
-static void remove_temporary_files(void)
-{
-	struct strbuf buf = STRBUF_INIT;
-	size_t dirlen, prefixlen;
-	DIR *dir;
-	struct dirent *e;
+struct existing_packs {
+	struct string_list kept_packs;
+	struct string_list non_kept_packs;
+	struct string_list cruft_packs;
+};
 
-	dir = opendir(packdir);
-	if (!dir)
-		return;
+#define EXISTING_PACKS_INIT { \
+	.kept_packs = STRING_LIST_INIT_DUP, \
+	.non_kept_packs = STRING_LIST_INIT_DUP, \
+	.cruft_packs = STRING_LIST_INIT_DUP, \
+}
 
-	/* Point at the slash at the end of ".../objects/pack/" */
-	dirlen = strlen(packdir) + 1;
-	strbuf_addstr(&buf, packtmp);
-	/* Hold the length of  ".tmp-%d-pack-" */
-	prefixlen = buf.len - dirlen;
+static int has_existing_non_kept_packs(const struct existing_packs *existing)
+{
+	return existing->non_kept_packs.nr || existing->cruft_packs.nr;
+}
 
-	while ((e = readdir(dir))) {
-		if (strncmp(e->d_name, buf.buf + dirlen, prefixlen))
-			continue;
-		strbuf_setlen(&buf, dirlen);
-		strbuf_addstr(&buf, e->d_name);
-		unlink(buf.buf);
-	}
-	closedir(dir);
-	strbuf_release(&buf);
+static void pack_mark_for_deletion(struct string_list_item *item)
+{
+	item->util = (void*)((uintptr_t)item->util | DELETE_PACK);
 }
 
-static void remove_pack_on_signal(int signo)
+static void pack_unmark_for_deletion(struct string_list_item *item)
 {
-	remove_temporary_files();
-	sigchain_pop(signo);
-	raise(signo);
+	item->util = (void*)((uintptr_t)item->util & ~DELETE_PACK);
 }
 
-/*
- * Adds all packs hex strings to the fname list, which do not
- * have a corresponding .keep file. These packs are not to
- * be kept if we are going to pack everything into one file.
- */
-static void get_non_kept_pack_filenames(struct string_list *fname_list,
-					const struct string_list *extra_keep)
+static int pack_is_marked_for_deletion(struct string_list_item *item)
 {
-	DIR *dir;
-	struct dirent *e;
-	char *fname;
+	return (uintptr_t)item->util & DELETE_PACK;
+}
 
-	if (!(dir = opendir(packdir)))
-		return;
+static void pack_mark_retained(struct string_list_item *item)
+{
+	item->util = (void*)((uintptr_t)item->util | RETAIN_PACK);
+}
 
-	while ((e = readdir(dir)) != NULL) {
-		size_t len;
-		int i;
+static int pack_is_retained(struct string_list_item *item)
+{
+	return (uintptr_t)item->util & RETAIN_PACK;
+}
 
-		for (i = 0; i < extra_keep->nr; i++)
-			if (!fspathcmp(e->d_name, extra_keep->items[i].string))
-				break;
-		if (extra_keep->nr > 0 && i < extra_keep->nr)
-			continue;
+static void mark_packs_for_deletion_1(struct string_list *names,
+				      struct string_list *list)
+{
+	struct string_list_item *item;
+	const int hexsz = the_hash_algo->hexsz;
 
-		if (!strip_suffix(e->d_name, ".pack", &len))
+	for_each_string_list_item(item, list) {
+		char *sha1;
+		size_t len = strlen(item->string);
+		if (len < hexsz)
 			continue;
+		sha1 = item->string + len - hexsz;
+
+		if (pack_is_retained(item)) {
+			pack_unmark_for_deletion(item);
+		} else if (!string_list_has_string(names, sha1)) {
+			/*
+			 * Mark this pack for deletion, which ensures
+			 * that this pack won't be included in a MIDX
+			 * (if `--write-midx` was given) and that we
+			 * will actually delete this pack (if `-d` was
+			 * given).
+			 */
+			pack_mark_for_deletion(item);
+		}
+	}
+}
 
-		fname = xmemdupz(e->d_name, len);
+static void retain_cruft_pack(struct existing_packs *existing,
+			      struct packed_git *cruft)
+{
+	struct strbuf buf = STRBUF_INIT;
+	struct string_list_item *item;
 
-		if (!file_exists(mkpath("%s/%s.keep", packdir, fname)))
-			string_list_append_nodup(fname_list, fname);
-		else
-			free(fname);
-	}
-	closedir(dir);
+	strbuf_addstr(&buf, pack_basename(cruft));
+	strbuf_strip_suffix(&buf, ".pack");
+
+	item = string_list_lookup(&existing->cruft_packs, buf.buf);
+	if (!item)
+		BUG("could not find cruft pack '%s'", pack_basename(cruft));
+
+	pack_mark_retained(item);
+	strbuf_release(&buf);
+}
+
+static void mark_packs_for_deletion(struct existing_packs *existing,
+				    struct string_list *names)
+
+{
+	mark_packs_for_deletion_1(names, &existing->non_kept_packs);
+	mark_packs_for_deletion_1(names, &existing->cruft_packs);
 }
 
 static void remove_redundant_pack(const char *dir_name, const char *base_name)
@@ -143,20 +203,75 @@ static void remove_redundant_pack(const char *dir_name, const char *base_name)
 	strbuf_release(&buf);
 }
 
-struct pack_objects_args {
-	const char *window;
-	const char *window_memory;
-	const char *depth;
-	const char *threads;
-	const char *max_pack_size;
-	int no_reuse_delta;
-	int no_reuse_object;
-	int quiet;
-	int local;
-};
+static void remove_redundant_packs_1(struct string_list *packs)
+{
+	struct string_list_item *item;
+	for_each_string_list_item(item, packs) {
+		if (!pack_is_marked_for_deletion(item))
+			continue;
+		remove_redundant_pack(packdir, item->string);
+	}
+}
+
+static void remove_redundant_existing_packs(struct existing_packs *existing)
+{
+	remove_redundant_packs_1(&existing->non_kept_packs);
+	remove_redundant_packs_1(&existing->cruft_packs);
+}
+
+static void existing_packs_release(struct existing_packs *existing)
+{
+	string_list_clear(&existing->kept_packs, 0);
+	string_list_clear(&existing->non_kept_packs, 0);
+	string_list_clear(&existing->cruft_packs, 0);
+}
+
+/*
+ * Adds all packs hex strings (pack-$HASH) to either packs->non_kept
+ * or packs->kept based on whether each pack has a corresponding
+ * .keep file or not.  Packs without a .keep file are not to be kept
+ * if we are going to pack everything into one file.
+ */
+static void collect_pack_filenames(struct existing_packs *existing,
+				   const struct string_list *extra_keep)
+{
+	struct packed_git *p;
+	struct strbuf buf = STRBUF_INIT;
+
+	for (p = get_all_packs(the_repository); p; p = p->next) {
+		int i;
+		const char *base;
+
+		if (!p->pack_local)
+			continue;
+
+		base = pack_basename(p);
+
+		for (i = 0; i < extra_keep->nr; i++)
+			if (!fspathcmp(base, extra_keep->items[i].string))
+				break;
+
+		strbuf_reset(&buf);
+		strbuf_addstr(&buf, base);
+		strbuf_strip_suffix(&buf, ".pack");
+
+		if ((extra_keep->nr > 0 && i < extra_keep->nr) || p->pack_keep)
+			string_list_append(&existing->kept_packs, buf.buf);
+		else if (p->is_cruft)
+			string_list_append(&existing->cruft_packs, buf.buf);
+		else
+			string_list_append(&existing->non_kept_packs, buf.buf);
+	}
+
+	string_list_sort(&existing->kept_packs);
+	string_list_sort(&existing->non_kept_packs);
+	string_list_sort(&existing->cruft_packs);
+	strbuf_release(&buf);
+}
 
 static void prepare_pack_objects(struct child_process *cmd,
-				 const struct pack_objects_args *args)
+				 const struct pack_objects_args *args,
+				 const char *out)
 {
 	strvec_push(&cmd->args, "pack-objects");
 	if (args->window)
@@ -168,7 +283,7 @@ static void prepare_pack_objects(struct child_process *cmd,
 	if (args->threads)
 		strvec_pushf(&cmd->args, "--threads=%s", args->threads);
 	if (args->max_pack_size)
-		strvec_pushf(&cmd->args, "--max-pack-size=%s", args->max_pack_size);
+		strvec_pushf(&cmd->args, "--max-pack-size=%lu", args->max_pack_size);
 	if (args->no_reuse_delta)
 		strvec_pushf(&cmd->args, "--no-reuse-delta");
 	if (args->no_reuse_object)
@@ -179,7 +294,7 @@ static void prepare_pack_objects(struct child_process *cmd,
 		strvec_push(&cmd->args,  "--quiet");
 	if (delta_base_offset)
 		strvec_push(&cmd->args,  "--delta-base-offset");
-	strvec_push(&cmd->args, packtmp);
+	strvec_push(&cmd->args, out);
 	cmd->git_cmd = 1;
 	cmd->out = -1;
 }
@@ -188,8 +303,9 @@ static void prepare_pack_objects(struct child_process *cmd,
  * Write oid to the given struct child_process's stdin, starting it first if
  * necessary.
  */
-static int write_oid(const struct object_id *oid, struct packed_git *pack,
-		     uint32_t pos, void *data)
+static int write_oid(const struct object_id *oid,
+		     struct packed_git *pack UNUSED,
+		     uint32_t pos UNUSED, void *data)
 {
 	struct child_process *cmd = data;
 
@@ -198,8 +314,9 @@ static int write_oid(const struct object_id *oid, struct packed_git *pack,
 			die(_("could not start pack-objects to repack promisor objects"));
 	}
 
-	xwrite(cmd->in, oid_to_hex(oid), the_hash_algo->hexsz);
-	xwrite(cmd->in, "\n", 1);
+	if (write_in_full(cmd->in, oid_to_hex(oid), the_hash_algo->hexsz) < 0 ||
+	    write_in_full(cmd->in, "\n", 1) < 0)
+		die(_("failed to feed promisor objects to pack-objects"));
 	return 0;
 }
 
@@ -208,17 +325,22 @@ static struct {
 	unsigned optional:1;
 } exts[] = {
 	{".pack"},
-	{".idx"},
 	{".rev", 1},
+	{".mtimes", 1},
 	{".bitmap", 1},
 	{".promisor", 1},
+	{".idx"},
 };
 
-static unsigned populate_pack_exts(char *name)
+struct generated_pack_data {
+	struct tempfile *tempfiles[ARRAY_SIZE(exts)];
+};
+
+static struct generated_pack_data *populate_pack_exts(const char *name)
 {
 	struct stat statbuf;
 	struct strbuf path = STRBUF_INIT;
-	unsigned ret = 0;
+	struct generated_pack_data *data = xcalloc(1, sizeof(*data));
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(exts); i++) {
@@ -228,11 +350,23 @@ static unsigned populate_pack_exts(char *name)
 		if (stat(path.buf, &statbuf))
 			continue;
 
-		ret |= (1 << i);
+		data->tempfiles[i] = register_tempfile(path.buf);
 	}
 
 	strbuf_release(&path);
-	return ret;
+	return data;
+}
+
+static int has_pack_ext(const struct generated_pack_data *data,
+			const char *ext)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(exts); i++) {
+		if (strcmp(exts[i].name, ext))
+			continue;
+		return !!data->tempfiles[i];
+	}
+	BUG("unknown pack extension: '%s'", ext);
 }
 
 static void repack_promisor_objects(const struct pack_objects_args *args,
@@ -242,7 +376,7 @@ static void repack_promisor_objects(const struct pack_objects_args *args,
 	FILE *out;
 	struct strbuf line = STRBUF_INIT;
 
-	prepare_pack_objects(&cmd, args);
+	prepare_pack_objects(&cmd, args, packtmp);
 	cmd.in = -1;
 
 	/*
@@ -255,9 +389,11 @@ static void repack_promisor_objects(const struct pack_objects_args *args,
 	for_each_packed_object(write_oid, &cmd,
 			       FOR_EACH_OBJECT_PROMISOR_ONLY);
 
-	if (cmd.in == -1)
+	if (cmd.in == -1) {
 		/* No packed objects; cmd was never started */
+		child_process_clear(&cmd);
 		return;
+	}
 
 	close(cmd.in);
 
@@ -285,7 +421,7 @@ static void repack_promisor_objects(const struct pack_objects_args *args,
 					  line.buf);
 		write_promisor_file(promisor_name, NULL, 0);
 
-		item->util = (void *)(uintptr_t)populate_pack_exts(item->string);
+		item->util = populate_pack_exts(item->string);
 
 		free(promisor_name);
 	}
@@ -294,13 +430,12 @@ static void repack_promisor_objects(const struct pack_objects_args *args,
 		die(_("could not finish pack-objects to repack promisor objects"));
 }
 
-#define ALL_INTO_ONE 1
-#define LOOSEN_UNREACHABLE 2
-
 struct pack_geometry {
 	struct packed_git **pack;
 	uint32_t pack_nr, pack_alloc;
 	uint32_t split;
+
+	int split_factor;
 };
 
 static uint32_t geometry_pack_weight(struct packed_git *p)
@@ -322,16 +457,45 @@ static int geometry_cmp(const void *va, const void *vb)
 	return 0;
 }
 
-static void init_pack_geometry(struct pack_geometry **geometry_p)
+static void init_pack_geometry(struct pack_geometry *geometry,
+			       struct existing_packs *existing,
+			       const struct pack_objects_args *args)
 {
 	struct packed_git *p;
-	struct pack_geometry *geometry;
-
-	*geometry_p = xcalloc(1, sizeof(struct pack_geometry));
-	geometry = *geometry_p;
+	struct strbuf buf = STRBUF_INIT;
 
 	for (p = get_all_packs(the_repository); p; p = p->next) {
-		if (!pack_kept_objects && p->pack_keep)
+		if (args->local && !p->pack_local)
+			/*
+			 * When asked to only repack local packfiles we skip
+			 * over any packfiles that are borrowed from alternate
+			 * object directories.
+			 */
+			continue;
+
+		if (!pack_kept_objects) {
+			/*
+			 * Any pack that has its pack_keep bit set will
+			 * appear in existing->kept_packs below, but
+			 * this saves us from doing a more expensive
+			 * check.
+			 */
+			if (p->pack_keep)
+				continue;
+
+			/*
+			 * The pack may be kept via the --keep-pack
+			 * option; check 'existing->kept_packs' to
+			 * determine whether to ignore it.
+			 */
+			strbuf_reset(&buf);
+			strbuf_addstr(&buf, pack_basename(p));
+			strbuf_strip_suffix(&buf, ".pack");
+
+			if (string_list_has_string(&existing->kept_packs, buf.buf))
+				continue;
+		}
+		if (p->is_cruft)
 			continue;
 
 		ALLOC_GROW(geometry->pack,
@@ -343,9 +507,10 @@ static void init_pack_geometry(struct pack_geometry **geometry_p)
 	}
 
 	QSORT(geometry->pack, geometry->pack_nr, geometry_cmp);
+	strbuf_release(&buf);
 }
 
-static void split_pack_geometry(struct pack_geometry *geometry, int factor)
+static void split_pack_geometry(struct pack_geometry *geometry)
 {
 	uint32_t i;
 	uint32_t split;
@@ -364,12 +529,14 @@ static void split_pack_geometry(struct pack_geometry *geometry, int factor)
 		struct packed_git *ours = geometry->pack[i];
 		struct packed_git *prev = geometry->pack[i - 1];
 
-		if (unsigned_mult_overflows(factor, geometry_pack_weight(prev)))
+		if (unsigned_mult_overflows(geometry->split_factor,
+					    geometry_pack_weight(prev)))
 			die(_("pack %s too large to consider in geometric "
 			      "progression"),
 			    prev->pack_name);
 
-		if (geometry_pack_weight(ours) < factor * geometry_pack_weight(prev))
+		if (geometry_pack_weight(ours) <
+		    geometry->split_factor * geometry_pack_weight(prev))
 			break;
 	}
 
@@ -404,10 +571,12 @@ static void split_pack_geometry(struct pack_geometry *geometry, int factor)
 	for (i = split; i < geometry->pack_nr; i++) {
 		struct packed_git *ours = geometry->pack[i];
 
-		if (unsigned_mult_overflows(factor, total_size))
+		if (unsigned_mult_overflows(geometry->split_factor,
+					    total_size))
 			die(_("pack %s too large to roll up"), ours->pack_name);
 
-		if (geometry_pack_weight(ours) < factor * total_size) {
+		if (geometry_pack_weight(ours) <
+		    geometry->split_factor * total_size) {
 			if (unsigned_add_overflows(total_size,
 						   geometry_pack_weight(ours)))
 				die(_("pack %s too large to roll up"),
@@ -422,15 +591,525 @@ static void split_pack_geometry(struct pack_geometry *geometry, int factor)
 	geometry->split = split;
 }
 
-static void clear_pack_geometry(struct pack_geometry *geometry)
+static struct packed_git *get_preferred_pack(struct pack_geometry *geometry)
+{
+	uint32_t i;
+
+	if (!geometry) {
+		/*
+		 * No geometry means either an all-into-one repack (in which
+		 * case there is only one pack left and it is the largest) or an
+		 * incremental one.
+		 *
+		 * If repacking incrementally, then we could check the size of
+		 * all packs to determine which should be preferred, but leave
+		 * this for later.
+		 */
+		return NULL;
+	}
+	if (geometry->split == geometry->pack_nr)
+		return NULL;
+
+	/*
+	 * The preferred pack is the largest pack above the split line. In
+	 * other words, it is the largest pack that does not get rolled up in
+	 * the geometric repack.
+	 */
+	for (i = geometry->pack_nr; i > geometry->split; i--)
+		/*
+		 * A pack that is not local would never be included in a
+		 * multi-pack index. We thus skip over any non-local packs.
+		 */
+		if (geometry->pack[i - 1]->pack_local)
+			return geometry->pack[i - 1];
+
+	return NULL;
+}
+
+static void geometry_remove_redundant_packs(struct pack_geometry *geometry,
+					    struct string_list *names,
+					    struct existing_packs *existing)
+{
+	struct strbuf buf = STRBUF_INIT;
+	uint32_t i;
+
+	for (i = 0; i < geometry->split; i++) {
+		struct packed_git *p = geometry->pack[i];
+		if (string_list_has_string(names, hash_to_hex(p->hash)))
+			continue;
+
+		strbuf_reset(&buf);
+		strbuf_addstr(&buf, pack_basename(p));
+		strbuf_strip_suffix(&buf, ".pack");
+
+		if ((p->pack_keep) ||
+		    (string_list_has_string(&existing->kept_packs, buf.buf)))
+			continue;
+
+		remove_redundant_pack(packdir, buf.buf);
+	}
+
+	strbuf_release(&buf);
+}
+
+static void free_pack_geometry(struct pack_geometry *geometry)
 {
 	if (!geometry)
 		return;
 
 	free(geometry->pack);
-	geometry->pack_nr = 0;
-	geometry->pack_alloc = 0;
-	geometry->split = 0;
+}
+
+struct midx_snapshot_ref_data {
+	struct tempfile *f;
+	struct oidset seen;
+	int preferred;
+};
+
+static int midx_snapshot_ref_one(const char *refname UNUSED,
+				 const struct object_id *oid,
+				 int flag UNUSED, void *_data)
+{
+	struct midx_snapshot_ref_data *data = _data;
+	struct object_id peeled;
+
+	if (!peel_iterated_oid(oid, &peeled))
+		oid = &peeled;
+
+	if (oidset_insert(&data->seen, oid))
+		return 0; /* already seen */
+
+	if (oid_object_info(the_repository, oid, NULL) != OBJ_COMMIT)
+		return 0;
+
+	fprintf(data->f->fp, "%s%s\n", data->preferred ? "+" : "",
+		oid_to_hex(oid));
+
+	return 0;
+}
+
+static void midx_snapshot_refs(struct tempfile *f)
+{
+	struct midx_snapshot_ref_data data;
+	const struct string_list *preferred = bitmap_preferred_tips(the_repository);
+
+	data.f = f;
+	data.preferred = 0;
+	oidset_init(&data.seen, 0);
+
+	if (!fdopen_tempfile(f, "w"))
+		 die(_("could not open tempfile %s for writing"),
+		     get_tempfile_path(f));
+
+	if (preferred) {
+		struct string_list_item *item;
+
+		data.preferred = 1;
+		for_each_string_list_item(item, preferred)
+			for_each_ref_in(item->string, midx_snapshot_ref_one, &data);
+		data.preferred = 0;
+	}
+
+	for_each_ref(midx_snapshot_ref_one, &data);
+
+	if (close_tempfile_gently(f)) {
+		int save_errno = errno;
+		delete_tempfile(&f);
+		errno = save_errno;
+		die_errno(_("could not close refs snapshot tempfile"));
+	}
+
+	oidset_clear(&data.seen);
+}
+
+static void midx_included_packs(struct string_list *include,
+				struct existing_packs *existing,
+				struct string_list *names,
+				struct pack_geometry *geometry)
+{
+	struct string_list_item *item;
+
+	for_each_string_list_item(item, &existing->kept_packs)
+		string_list_insert(include, xstrfmt("%s.idx", item->string));
+	for_each_string_list_item(item, names)
+		string_list_insert(include, xstrfmt("pack-%s.idx", item->string));
+	if (geometry->split_factor) {
+		struct strbuf buf = STRBUF_INIT;
+		uint32_t i;
+		for (i = geometry->split; i < geometry->pack_nr; i++) {
+			struct packed_git *p = geometry->pack[i];
+
+			/*
+			 * The multi-pack index never refers to packfiles part
+			 * of an alternate object database, so we skip these.
+			 * While git-multi-pack-index(1) would silently ignore
+			 * them anyway, this allows us to skip executing the
+			 * command completely when we have only non-local
+			 * packfiles.
+			 */
+			if (!p->pack_local)
+				continue;
+
+			strbuf_addstr(&buf, pack_basename(p));
+			strbuf_strip_suffix(&buf, ".pack");
+			strbuf_addstr(&buf, ".idx");
+
+			string_list_insert(include, strbuf_detach(&buf, NULL));
+		}
+	} else {
+		for_each_string_list_item(item, &existing->non_kept_packs) {
+			if (pack_is_marked_for_deletion(item))
+				continue;
+			string_list_insert(include, xstrfmt("%s.idx", item->string));
+		}
+	}
+
+	for_each_string_list_item(item, &existing->cruft_packs) {
+		/*
+		 * When doing a --geometric repack, there is no need to check
+		 * for deleted packs, since we're by definition not doing an
+		 * ALL_INTO_ONE repack (hence no packs will be deleted).
+		 * Otherwise we must check for and exclude any packs which are
+		 * enqueued for deletion.
+		 *
+		 * So we could omit the conditional below in the --geometric
+		 * case, but doing so is unnecessary since no packs are marked
+		 * as pending deletion (since we only call
+		 * `mark_packs_for_deletion()` when doing an all-into-one
+		 * repack).
+		 */
+		if (pack_is_marked_for_deletion(item))
+			continue;
+		string_list_insert(include, xstrfmt("%s.idx", item->string));
+	}
+}
+
+static int write_midx_included_packs(struct string_list *include,
+				     struct pack_geometry *geometry,
+				     struct string_list *names,
+				     const char *refs_snapshot,
+				     int show_progress, int write_bitmaps)
+{
+	struct child_process cmd = CHILD_PROCESS_INIT;
+	struct string_list_item *item;
+	struct packed_git *preferred = get_preferred_pack(geometry);
+	FILE *in;
+	int ret;
+
+	if (!include->nr)
+		return 0;
+
+	cmd.in = -1;
+	cmd.git_cmd = 1;
+
+	strvec_push(&cmd.args, "multi-pack-index");
+	strvec_pushl(&cmd.args, "write", "--stdin-packs", NULL);
+
+	if (show_progress)
+		strvec_push(&cmd.args, "--progress");
+	else
+		strvec_push(&cmd.args, "--no-progress");
+
+	if (write_bitmaps)
+		strvec_push(&cmd.args, "--bitmap");
+
+	if (preferred)
+		strvec_pushf(&cmd.args, "--preferred-pack=%s",
+			     pack_basename(preferred));
+	else if (names->nr) {
+		/* The largest pack was repacked, meaning that either
+		 * one or two packs exist depending on whether the
+		 * repository has a cruft pack or not.
+		 *
+		 * Select the non-cruft one as preferred to encourage
+		 * pack-reuse among packs containing reachable objects
+		 * over unreachable ones.
+		 *
+		 * (Note we could write multiple packs here if
+		 * `--max-pack-size` was given, but any one of them
+		 * will suffice, so pick the first one.)
+		 */
+		for_each_string_list_item(item, names) {
+			struct generated_pack_data *data = item->util;
+			if (has_pack_ext(data, ".mtimes"))
+				continue;
+
+			strvec_pushf(&cmd.args, "--preferred-pack=pack-%s.pack",
+				     item->string);
+			break;
+		}
+	} else {
+		/*
+		 * No packs were kept, and no packs were written. The
+		 * only thing remaining are .keep packs (unless
+		 * --pack-kept-objects was given).
+		 *
+		 * Set the `--preferred-pack` arbitrarily here.
+		 */
+		;
+	}
+
+	if (refs_snapshot)
+		strvec_pushf(&cmd.args, "--refs-snapshot=%s", refs_snapshot);
+
+	ret = start_command(&cmd);
+	if (ret)
+		return ret;
+
+	in = xfdopen(cmd.in, "w");
+	for_each_string_list_item(item, include)
+		fprintf(in, "%s\n", item->string);
+	fclose(in);
+
+	return finish_command(&cmd);
+}
+
+static void remove_redundant_bitmaps(struct string_list *include,
+				     const char *packdir)
+{
+	struct strbuf path = STRBUF_INIT;
+	struct string_list_item *item;
+	size_t packdir_len;
+
+	strbuf_addstr(&path, packdir);
+	strbuf_addch(&path, '/');
+	packdir_len = path.len;
+
+	/*
+	 * Remove any pack bitmaps corresponding to packs which are now
+	 * included in the MIDX.
+	 */
+	for_each_string_list_item(item, include) {
+		strbuf_addstr(&path, item->string);
+		strbuf_strip_suffix(&path, ".idx");
+		strbuf_addstr(&path, ".bitmap");
+
+		if (unlink(path.buf) && errno != ENOENT)
+			warning_errno(_("could not remove stale bitmap: %s"),
+				      path.buf);
+
+		strbuf_setlen(&path, packdir_len);
+	}
+	strbuf_release(&path);
+}
+
+static int finish_pack_objects_cmd(struct child_process *cmd,
+				   struct string_list *names,
+				   int local)
+{
+	FILE *out;
+	struct strbuf line = STRBUF_INIT;
+
+	out = xfdopen(cmd->out, "r");
+	while (strbuf_getline_lf(&line, out) != EOF) {
+		struct string_list_item *item;
+
+		if (line.len != the_hash_algo->hexsz)
+			die(_("repack: Expecting full hex object ID lines only "
+			      "from pack-objects."));
+		/*
+		 * Avoid putting packs written outside of the repository in the
+		 * list of names.
+		 */
+		if (local) {
+			item = string_list_append(names, line.buf);
+			item->util = populate_pack_exts(line.buf);
+		}
+	}
+	fclose(out);
+
+	strbuf_release(&line);
+
+	return finish_command(cmd);
+}
+
+static int write_filtered_pack(const struct pack_objects_args *args,
+			       const char *destination,
+			       const char *pack_prefix,
+			       struct existing_packs *existing,
+			       struct string_list *names)
+{
+	struct child_process cmd = CHILD_PROCESS_INIT;
+	struct string_list_item *item;
+	FILE *in;
+	int ret;
+	const char *caret;
+	const char *scratch;
+	int local = skip_prefix(destination, packdir, &scratch);
+
+	prepare_pack_objects(&cmd, args, destination);
+
+	strvec_push(&cmd.args, "--stdin-packs");
+
+	if (!pack_kept_objects)
+		strvec_push(&cmd.args, "--honor-pack-keep");
+	for_each_string_list_item(item, &existing->kept_packs)
+		strvec_pushf(&cmd.args, "--keep-pack=%s", item->string);
+
+	cmd.in = -1;
+
+	ret = start_command(&cmd);
+	if (ret)
+		return ret;
+
+	/*
+	 * Here 'names' contains only the pack(s) that were just
+	 * written, which is exactly the packs we want to keep. Also
+	 * 'existing_kept_packs' already contains the packs in
+	 * 'keep_pack_list'.
+	 */
+	in = xfdopen(cmd.in, "w");
+	for_each_string_list_item(item, names)
+		fprintf(in, "^%s-%s.pack\n", pack_prefix, item->string);
+	for_each_string_list_item(item, &existing->non_kept_packs)
+		fprintf(in, "%s.pack\n", item->string);
+	for_each_string_list_item(item, &existing->cruft_packs)
+		fprintf(in, "%s.pack\n", item->string);
+	caret = pack_kept_objects ? "" : "^";
+	for_each_string_list_item(item, &existing->kept_packs)
+		fprintf(in, "%s%s.pack\n", caret, item->string);
+	fclose(in);
+
+	return finish_pack_objects_cmd(&cmd, names, local);
+}
+
+static int existing_cruft_pack_cmp(const void *va, const void *vb)
+{
+	struct packed_git *a = *(struct packed_git **)va;
+	struct packed_git *b = *(struct packed_git **)vb;
+
+	if (a->pack_size < b->pack_size)
+		return -1;
+	if (a->pack_size > b->pack_size)
+		return 1;
+	return 0;
+}
+
+static void collapse_small_cruft_packs(FILE *in, size_t max_size,
+				       struct existing_packs *existing)
+{
+	struct packed_git **existing_cruft, *p;
+	struct strbuf buf = STRBUF_INIT;
+	size_t total_size = 0;
+	size_t existing_cruft_nr = 0;
+	size_t i;
+
+	ALLOC_ARRAY(existing_cruft, existing->cruft_packs.nr);
+
+	for (p = get_all_packs(the_repository); p; p = p->next) {
+		if (!(p->is_cruft && p->pack_local))
+			continue;
+
+		strbuf_reset(&buf);
+		strbuf_addstr(&buf, pack_basename(p));
+		strbuf_strip_suffix(&buf, ".pack");
+
+		if (!string_list_has_string(&existing->cruft_packs, buf.buf))
+			continue;
+
+		if (existing_cruft_nr >= existing->cruft_packs.nr)
+			BUG("too many cruft packs (found %"PRIuMAX", but knew "
+			    "of %"PRIuMAX")",
+			    (uintmax_t)existing_cruft_nr + 1,
+			    (uintmax_t)existing->cruft_packs.nr);
+		existing_cruft[existing_cruft_nr++] = p;
+	}
+
+	QSORT(existing_cruft, existing_cruft_nr, existing_cruft_pack_cmp);
+
+	for (i = 0; i < existing_cruft_nr; i++) {
+		size_t proposed;
+
+		p = existing_cruft[i];
+		proposed = st_add(total_size, p->pack_size);
+
+		if (proposed <= max_size) {
+			total_size = proposed;
+			fprintf(in, "-%s\n", pack_basename(p));
+		} else {
+			retain_cruft_pack(existing, p);
+			fprintf(in, "%s\n", pack_basename(p));
+		}
+	}
+
+	for (i = 0; i < existing->non_kept_packs.nr; i++)
+		fprintf(in, "-%s.pack\n",
+			existing->non_kept_packs.items[i].string);
+
+	strbuf_release(&buf);
+	free(existing_cruft);
+}
+
+static int write_cruft_pack(const struct pack_objects_args *args,
+			    const char *destination,
+			    const char *pack_prefix,
+			    const char *cruft_expiration,
+			    struct string_list *names,
+			    struct existing_packs *existing)
+{
+	struct child_process cmd = CHILD_PROCESS_INIT;
+	struct string_list_item *item;
+	FILE *in;
+	int ret;
+	const char *scratch;
+	int local = skip_prefix(destination, packdir, &scratch);
+
+	prepare_pack_objects(&cmd, args, destination);
+
+	strvec_push(&cmd.args, "--cruft");
+	if (cruft_expiration)
+		strvec_pushf(&cmd.args, "--cruft-expiration=%s",
+			     cruft_expiration);
+
+	strvec_push(&cmd.args, "--honor-pack-keep");
+	strvec_push(&cmd.args, "--non-empty");
+
+	cmd.in = -1;
+
+	ret = start_command(&cmd);
+	if (ret)
+		return ret;
+
+	/*
+	 * names has a confusing double use: it both provides the list
+	 * of just-written new packs, and accepts the name of the cruft
+	 * pack we are writing.
+	 *
+	 * By the time it is read here, it contains only the pack(s)
+	 * that were just written, which is exactly the set of packs we
+	 * want to consider kept.
+	 *
+	 * If `--expire-to` is given, the double-use served by `names`
+	 * ensures that the pack written to `--expire-to` excludes any
+	 * objects contained in the cruft pack.
+	 */
+	in = xfdopen(cmd.in, "w");
+	for_each_string_list_item(item, names)
+		fprintf(in, "%s-%s.pack\n", pack_prefix, item->string);
+	if (args->max_pack_size && !cruft_expiration) {
+		collapse_small_cruft_packs(in, args->max_pack_size, existing);
+	} else {
+		for_each_string_list_item(item, &existing->non_kept_packs)
+			fprintf(in, "-%s.pack\n", item->string);
+		for_each_string_list_item(item, &existing->cruft_packs)
+			fprintf(in, "-%s.pack\n", item->string);
+	}
+	for_each_string_list_item(item, &existing->kept_packs)
+		fprintf(in, "%s.pack\n", item->string);
+	fclose(in);
+
+	return finish_pack_objects_cmd(&cmd, names, local);
+}
+
+static const char *find_pack_prefix(const char *packdir, const char *packtmp)
+{
+	const char *pack_prefix;
+	if (!skip_prefix(packtmp, packdir, &pack_prefix))
+		die(_("pack prefix %s does not begin with objdir %s"),
+		    packtmp, packdir);
+	if (*pack_prefix == '/')
+		pack_prefix++;
+	return pack_prefix;
 }
 
 int cmd_repack(int argc, const char **argv, const char *prefix)
@@ -438,22 +1117,23 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	struct child_process cmd = CHILD_PROCESS_INIT;
 	struct string_list_item *item;
 	struct string_list names = STRING_LIST_INIT_DUP;
-	struct string_list rollback = STRING_LIST_INIT_NODUP;
-	struct string_list existing_packs = STRING_LIST_INIT_DUP;
-	struct pack_geometry *geometry = NULL;
-	struct strbuf line = STRBUF_INIT;
+	struct existing_packs existing = EXISTING_PACKS_INIT;
+	struct pack_geometry geometry = { 0 };
+	struct tempfile *refs_snapshot = NULL;
 	int i, ext, ret;
-	FILE *out;
+	int show_progress;
 
 	/* variables to be filled by option parsing */
-	int pack_everything = 0;
 	int delete_redundant = 0;
 	const char *unpack_unreachable = NULL;
 	int keep_unreachable = 0;
 	struct string_list keep_pack_list = STRING_LIST_INIT_NODUP;
-	int no_update_server_info = 0;
 	struct pack_objects_args po_args = {NULL};
-	int geometric_factor = 0;
+	struct pack_objects_args cruft_po_args = {NULL};
+	int write_midx = 0;
+	const char *cruft_expiration = NULL;
+	const char *expire_to = NULL;
+	const char *filter_to = NULL;
 
 	struct option builtin_repack_options[] = {
 		OPT_BIT('a', NULL, &pack_everything,
@@ -461,14 +1141,21 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 		OPT_BIT('A', NULL, &pack_everything,
 				N_("same as -a, and turn unreachable objects loose"),
 				   LOOSEN_UNREACHABLE | ALL_INTO_ONE),
+		OPT_BIT(0, "cruft", &pack_everything,
+				N_("same as -a, pack unreachable cruft objects separately"),
+				   PACK_CRUFT),
+		OPT_STRING(0, "cruft-expiration", &cruft_expiration, N_("approxidate"),
+				N_("with --cruft, expire objects older than this")),
+		OPT_MAGNITUDE(0, "max-cruft-size", &cruft_po_args.max_pack_size,
+				N_("with --cruft, limit the size of new cruft packs")),
 		OPT_BOOL('d', NULL, &delete_redundant,
 				N_("remove redundant packs, and run git-prune-packed")),
 		OPT_BOOL('f', NULL, &po_args.no_reuse_delta,
 				N_("pass --no-reuse-delta to git-pack-objects")),
 		OPT_BOOL('F', NULL, &po_args.no_reuse_object,
 				N_("pass --no-reuse-object to git-pack-objects")),
-		OPT_BOOL('n', NULL, &no_update_server_info,
-				N_("do not run git-update-server-info")),
+		OPT_NEGBIT('n', NULL, &run_update_server_info,
+				N_("do not run git-update-server-info"), 1),
 		OPT__QUIET(&po_args.quiet, N_("be quiet")),
 		OPT_BOOL('l', "local", &po_args.local,
 				N_("pass --local to git-pack-objects")),
@@ -488,18 +1175,27 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 				N_("limits the maximum delta depth")),
 		OPT_STRING(0, "threads", &po_args.threads, N_("n"),
 				N_("limits the maximum number of threads")),
-		OPT_STRING(0, "max-pack-size", &po_args.max_pack_size, N_("bytes"),
+		OPT_MAGNITUDE(0, "max-pack-size", &po_args.max_pack_size,
 				N_("maximum size of each packfile")),
+		OPT_PARSE_LIST_OBJECTS_FILTER(&po_args.filter_options),
 		OPT_BOOL(0, "pack-kept-objects", &pack_kept_objects,
 				N_("repack objects in packs marked with .keep")),
 		OPT_STRING_LIST(0, "keep-pack", &keep_pack_list, N_("name"),
 				N_("do not repack this pack")),
-		OPT_INTEGER('g', "geometric", &geometric_factor,
+		OPT_INTEGER('g', "geometric", &geometry.split_factor,
 			    N_("find a geometric progression with factor <N>")),
+		OPT_BOOL('m', "write-midx", &write_midx,
+			   N_("write a multi-pack index of the resulting packs")),
+		OPT_STRING(0, "expire-to", &expire_to, N_("dir"),
+			   N_("pack prefix to store a pack containing pruned objects")),
+		OPT_STRING(0, "filter-to", &filter_to, N_("dir"),
+			   N_("pack prefix to store a pack containing filtered out objects")),
 		OPT_END()
 	};
 
-	git_config(repack_config, NULL);
+	list_objects_filter_init(&po_args.filter_options);
+
+	git_config(repack_config, &cruft_po_args);
 
 	argc = parse_options(argc, argv, prefix, builtin_repack_options,
 				git_repack_usage, 0);
@@ -507,35 +1203,68 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	if (delete_redundant && repository_format_precious_objects)
 		die(_("cannot delete packs in a precious-objects repo"));
 
-	if (keep_unreachable &&
-	    (unpack_unreachable || (pack_everything & LOOSEN_UNREACHABLE)))
-		die(_("--keep-unreachable and -A are incompatible"));
+	die_for_incompatible_opt3(unpack_unreachable || (pack_everything & LOOSEN_UNREACHABLE), "-A",
+				  keep_unreachable, "-k/--keep-unreachable",
+				  pack_everything & PACK_CRUFT, "--cruft");
+
+	if (pack_everything & PACK_CRUFT)
+		pack_everything |= ALL_INTO_ONE;
 
 	if (write_bitmaps < 0) {
-		if (!(pack_everything & ALL_INTO_ONE) ||
-		    !is_bare_repository())
+		if (!write_midx &&
+		    (!(pack_everything & ALL_INTO_ONE) || !is_bare_repository()))
 			write_bitmaps = 0;
+	} else if (write_bitmaps &&
+		   git_env_bool(GIT_TEST_MULTI_PACK_INDEX, 0) &&
+		   git_env_bool(GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP, 0)) {
+		write_bitmaps = 0;
 	}
 	if (pack_kept_objects < 0)
-		pack_kept_objects = write_bitmaps > 0;
+		pack_kept_objects = write_bitmaps > 0 && !write_midx;
 
-	if (write_bitmaps && !(pack_everything & ALL_INTO_ONE))
+	if (write_bitmaps && !(pack_everything & ALL_INTO_ONE) && !write_midx)
 		die(_(incremental_bitmap_conflict_error));
 
-	if (geometric_factor) {
-		if (pack_everything)
-			die(_("--geometric is incompatible with -A, -a"));
-		init_pack_geometry(&geometry);
-		split_pack_geometry(geometry, geometric_factor);
+	if (write_bitmaps && po_args.local && has_alt_odb(the_repository)) {
+		/*
+		 * When asked to do a local repack, but we have
+		 * packfiles that are inherited from an alternate, then
+		 * we cannot guarantee that the multi-pack-index would
+		 * have full coverage of all objects. We thus disable
+		 * writing bitmaps in that case.
+		 */
+		warning(_("disabling bitmap writing, as some objects are not being packed"));
+		write_bitmaps = 0;
+	}
+
+	if (write_midx && write_bitmaps) {
+		struct strbuf path = STRBUF_INIT;
+
+		strbuf_addf(&path, "%s/%s_XXXXXX", get_object_directory(),
+			    "bitmap-ref-tips");
+
+		refs_snapshot = xmks_tempfile(path.buf);
+		midx_snapshot_refs(refs_snapshot);
+
+		strbuf_release(&path);
 	}
 
 	packdir = mkpathdup("%s/pack", get_object_directory());
 	packtmp_name = xstrfmt(".tmp-%d-pack", (int)getpid());
 	packtmp = mkpathdup("%s/%s", packdir, packtmp_name);
 
-	sigchain_push_common(remove_pack_on_signal);
+	collect_pack_filenames(&existing, &keep_pack_list);
+
+	if (geometry.split_factor) {
+		if (pack_everything)
+			die(_("options '%s' and '%s' cannot be used together"), "--geometric", "-A/-a");
+		init_pack_geometry(&geometry, &existing, &po_args);
+		split_pack_geometry(&geometry);
+	}
+
+	prepare_pack_objects(&cmd, &po_args, packtmp);
 
-	prepare_pack_objects(&cmd, &po_args);
+	show_progress = !po_args.quiet && isatty(2);
 
 	strvec_push(&cmd.args, "--keep-true-parents");
 	if (!pack_kept_objects)
@@ -544,7 +1273,7 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 		strvec_pushf(&cmd.args, "--keep-pack=%s",
 			     keep_pack_list.items[i].string);
 	strvec_push(&cmd.args, "--non-empty");
-	if (!geometry) {
+	if (!geometry.split_factor) {
 		/*
 		 * We need to grab all reachable objects, including those that
 		 * are reachable from reflogs and the index.
@@ -559,21 +1288,23 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 		strvec_push(&cmd.args, "--reflog");
 		strvec_push(&cmd.args, "--indexed-objects");
 	}
-	if (has_promisor_remote())
+	if (repo_has_promisor_remote(the_repository))
 		strvec_push(&cmd.args, "--exclude-promisor-objects");
-	if (write_bitmaps > 0)
-		strvec_push(&cmd.args, "--write-bitmap-index");
-	else if (write_bitmaps < 0)
-		strvec_push(&cmd.args, "--write-bitmap-index-quiet");
+	if (!write_midx) {
+		if (write_bitmaps > 0)
+			strvec_push(&cmd.args, "--write-bitmap-index");
+		else if (write_bitmaps < 0)
+			strvec_push(&cmd.args, "--write-bitmap-index-quiet");
+	}
 	if (use_delta_islands)
 		strvec_push(&cmd.args, "--delta-islands");
 
 	if (pack_everything & ALL_INTO_ONE) {
-		get_non_kept_pack_filenames(&existing_packs, &keep_pack_list);
-
 		repack_promisor_objects(&po_args, &names);
 
-		if (existing_packs.nr && delete_redundant) {
+		if (has_existing_non_kept_packs(&existing) &&
+		    delete_redundant &&
+		    !(pack_everything & PACK_CRUFT)) {
 			for_each_string_list_item(item, &names) {
 				strvec_pushf(&cmd.args, "--keep-pack=%s-%s.pack",
 					     packtmp_name, item->string);
@@ -582,18 +1313,15 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 				strvec_pushf(&cmd.args,
 					     "--unpack-unreachable=%s",
 					     unpack_unreachable);
-				strvec_push(&cmd.env_array, "GIT_REF_PARANOIA=1");
 			} else if (pack_everything & LOOSEN_UNREACHABLE) {
 				strvec_push(&cmd.args,
 					    "--unpack-unreachable");
 			} else if (keep_unreachable) {
 				strvec_push(&cmd.args, "--keep-unreachable");
 				strvec_push(&cmd.args, "--pack-loose-unreachable");
-			} else {
-				strvec_push(&cmd.env_array, "GIT_REF_PARANOIA=1");
 			}
 		}
-	} else if (geometry) {
+	} else if (geometry.split_factor) {
 		strvec_push(&cmd.args, "--stdin-packs");
 		strvec_push(&cmd.args, "--unpacked");
 	} else {
@@ -601,116 +1329,179 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 		strvec_push(&cmd.args, "--incremental");
 	}
 
-	if (geometry)
+	if (po_args.filter_options.choice)
+		strvec_pushf(&cmd.args, "--filter=%s",
+			     expand_list_objects_filter_spec(&po_args.filter_options));
+	else if (filter_to)
+		die(_("option '%s' can only be used along with '%s'"), "--filter-to", "--filter");
+
+	if (geometry.split_factor)
 		cmd.in = -1;
 	else
 		cmd.no_stdin = 1;
 
 	ret = start_command(&cmd);
 	if (ret)
-		return ret;
+		goto cleanup;
 
-	if (geometry) {
+	if (geometry.split_factor) {
 		FILE *in = xfdopen(cmd.in, "w");
 		/*
 		 * The resulting pack should contain all objects in packs that
 		 * are going to be rolled up, but exclude objects in packs which
 		 * are being left alone.
 		 */
-		for (i = 0; i < geometry->split; i++)
-			fprintf(in, "%s\n", pack_basename(geometry->pack[i]));
-		for (i = geometry->split; i < geometry->pack_nr; i++)
-			fprintf(in, "^%s\n", pack_basename(geometry->pack[i]));
+		for (i = 0; i < geometry.split; i++)
+			fprintf(in, "%s\n", pack_basename(geometry.pack[i]));
+		for (i = geometry.split; i < geometry.pack_nr; i++)
+			fprintf(in, "^%s\n", pack_basename(geometry.pack[i]));
 		fclose(in);
 	}
 
-	out = xfdopen(cmd.out, "r");
-	while (strbuf_getline_lf(&line, out) != EOF) {
-		if (line.len != the_hash_algo->hexsz)
-			die(_("repack: Expecting full hex object ID lines only from pack-objects."));
-		string_list_append(&names, line.buf);
-	}
-	fclose(out);
-	ret = finish_command(&cmd);
+	ret = finish_pack_objects_cmd(&cmd, &names, 1);
 	if (ret)
-		return ret;
+		goto cleanup;
 
 	if (!names.nr && !po_args.quiet)
 		printf_ln(_("Nothing new to pack."));
 
-	for_each_string_list_item(item, &names) {
-		item->util = (void *)(uintptr_t)populate_pack_exts(item->string);
+	if (pack_everything & PACK_CRUFT) {
+		const char *pack_prefix = find_pack_prefix(packdir, packtmp);
+
+		if (!cruft_po_args.window)
+			cruft_po_args.window = po_args.window;
+		if (!cruft_po_args.window_memory)
+			cruft_po_args.window_memory = po_args.window_memory;
+		if (!cruft_po_args.depth)
+			cruft_po_args.depth = po_args.depth;
+		if (!cruft_po_args.threads)
+			cruft_po_args.threads = po_args.threads;
+		if (!cruft_po_args.max_pack_size)
+			cruft_po_args.max_pack_size = po_args.max_pack_size;
+
+		cruft_po_args.local = po_args.local;
+		cruft_po_args.quiet = po_args.quiet;
+
+		ret = write_cruft_pack(&cruft_po_args, packtmp, pack_prefix,
+				       cruft_expiration, &names,
+				       &existing);
+		if (ret)
+			goto cleanup;
+
+		if (delete_redundant && expire_to) {
+			/*
+			 * If `--expire-to` is given with `-d`, it's possible
+			 * that we're about to prune some objects. With cruft
+			 * packs, pruning is implicit: any objects from existing
+			 * packs that weren't picked up by new packs are removed
+			 * when their packs are deleted.
+			 *
+			 * Generate an additional cruft pack, with one twist:
+			 * `names` now includes the name of the cruft pack
+			 * written in the previous step. So the contents of
+			 * _this_ cruft pack exclude everything contained in the
+			 * existing cruft pack (that is, all of the unreachable
+			 * objects which are no older than
+			 * `--cruft-expiration`).
+			 *
+			 * To make this work, cruft_expiration must become NULL
+			 * so that this cruft pack doesn't actually prune any
+			 * objects. If it were non-NULL, this call would always
+			 * generate an empty pack (since every object not in the
+			 * cruft pack generated above will have an mtime older
+			 * than the expiration).
+			 */
+			ret = write_cruft_pack(&cruft_po_args, expire_to,
+					       pack_prefix,
+					       NULL,
+					       &names,
+					       &existing);
+			if (ret)
+				goto cleanup;
+		}
+	}
+
+	if (po_args.filter_options.choice) {
+		if (!filter_to)
+			filter_to = packtmp;
+
+		ret = write_filtered_pack(&po_args,
+					  filter_to,
+					  find_pack_prefix(packdir, packtmp),
+					  &existing,
+					  &names);
+		if (ret)
+			goto cleanup;
 	}
 
+	string_list_sort(&names);
+
 	close_object_store(the_repository->objects);
 
 	/*
 	 * Ok we have prepared all new packfiles.
 	 */
 	for_each_string_list_item(item, &names) {
+		struct generated_pack_data *data = item->util;
+
 		for (ext = 0; ext < ARRAY_SIZE(exts); ext++) {
-			char *fname, *fname_old;
+			char *fname;
 
 			fname = mkpathdup("%s/pack-%s%s",
 					packdir, item->string, exts[ext].name);
-			fname_old = mkpathdup("%s-%s%s",
-					packtmp, item->string, exts[ext].name);
 
-			if (((uintptr_t)item->util) & (1 << ext)) {
+			if (data->tempfiles[ext]) {
+				const char *fname_old = get_tempfile_path(data->tempfiles[ext]);
 				struct stat statbuffer;
+
 				if (!stat(fname_old, &statbuffer)) {
 					statbuffer.st_mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
 					chmod(fname_old, statbuffer.st_mode);
 				}
 
-				if (rename(fname_old, fname))
-					die_errno(_("renaming '%s' failed"), fname_old);
+				if (rename_tempfile(&data->tempfiles[ext], fname))
+					die_errno(_("renaming pack to '%s' failed"), fname);
 			} else if (!exts[ext].optional)
-				die(_("missing required file: %s"), fname_old);
+				die(_("pack-objects did not write a '%s' file for pack %s-%s"),
+				    exts[ext].name, packtmp, item->string);
 			else if (unlink(fname) < 0 && errno != ENOENT)
 				die_errno(_("could not unlink: %s"), fname);
 
 			free(fname);
-			free(fname_old);
 		}
 	}
 	/* End of pack replacement. */
 
-	reprepare_packed_git(the_repository);
+	if (delete_redundant && pack_everything & ALL_INTO_ONE)
+		mark_packs_for_deletion(&existing, &names);
 
-	if (delete_redundant) {
-		const int hexsz = the_hash_algo->hexsz;
-		int opts = 0;
-		string_list_sort(&names);
-		for_each_string_list_item(item, &existing_packs) {
-			char *sha1;
-			size_t len = strlen(item->string);
-			if (len < hexsz)
-				continue;
-			sha1 = item->string + len - hexsz;
-			if (!string_list_has_string(&names, sha1))
-				remove_redundant_pack(packdir, item->string);
-		}
+	if (write_midx) {
+		struct string_list include = STRING_LIST_INIT_NODUP;
+		midx_included_packs(&include, &existing, &names, &geometry);
 
-		if (geometry) {
-			struct strbuf buf = STRBUF_INIT;
+		ret = write_midx_included_packs(&include, &geometry, &names,
+						refs_snapshot ? get_tempfile_path(refs_snapshot) : NULL,
+						show_progress, write_bitmaps > 0);
 
-			uint32_t i;
-			for (i = 0; i < geometry->split; i++) {
-				struct packed_git *p = geometry->pack[i];
-				if (string_list_has_string(&names,
-							   hash_to_hex(p->hash)))
-					continue;
+		if (!ret && write_bitmaps)
+			remove_redundant_bitmaps(&include, packdir);
 
-				strbuf_reset(&buf);
-				strbuf_addstr(&buf, pack_basename(p));
-				strbuf_strip_suffix(&buf, ".pack");
+		string_list_clear(&include, 0);
 
-				remove_redundant_pack(packdir, buf.buf);
-			}
-			strbuf_release(&buf);
-		}
-		if (!po_args.quiet && isatty(2))
+		if (ret)
+			goto cleanup;
+	}
+
+	reprepare_packed_git(the_repository);
+
+	if (delete_redundant) {
+		int opts = 0;
+		remove_redundant_existing_packs(&existing);
+
+		if (geometry.split_factor)
+			geometry_remove_redundant_packs(&geometry, &names,
+							&existing);
+		if (show_progress)
 			opts |= PRUNE_PACKED_VERBOSE;
 		prune_packed_objects(opts);
 
@@ -721,18 +1512,21 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 			prune_shallow(PRUNE_QUICK);
 	}
 
-	if (!no_update_server_info)
+	if (run_update_server_info)
 		update_server_info(0);
-	remove_temporary_files();
 
-	if (git_env_bool(GIT_TEST_MULTI_PACK_INDEX, 0))
-		write_midx_file(get_object_directory(), NULL, 0);
+	if (git_env_bool(GIT_TEST_MULTI_PACK_INDEX, 0)) {
+		unsigned flags = 0;
+		if (git_env_bool(GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP, 0))
+			flags |= MIDX_WRITE_BITMAP | MIDX_WRITE_REV_INDEX;
+		write_midx_file(get_object_directory(), NULL, NULL, flags);
+	}
 
-	string_list_clear(&names, 0);
-	string_list_clear(&rollback, 0);
-	string_list_clear(&existing_packs, 0);
-	clear_pack_geometry(geometry);
-	strbuf_release(&line);
+cleanup:
+	string_list_clear(&names, 1);
+	existing_packs_release(&existing);
+	free_pack_geometry(&geometry);
+	list_objects_filter_release(&po_args.filter_options);
 
-	return 0;
+	return ret;
 }