Multi-pack-index (MIDX)

index 14b32e1373..6a7aa00cf2 100644
@@ -5,7 +5,7 @@
 #include "midx.h"
 
 static char const * const builtin_multi_pack_index_usage[] = {
-	N_("git multi-pack-index [--object-dir <dir>] [write]"),
+	N_("git multi-pack-index [--object-dir=<dir>] write"),
 	NULL
 };
 

@@ -18,14 +18,10 @@ int cmd_multi_pack_index(int argc, const char **argv,
 {
 	static struct option builtin_multi_pack_index_options[] = {
 		OPT_FILENAME(0, "object-dir", &opts.object_dir,
-		  N_("The object directory containing set of packfile and pack-index pairs")),
+		  N_("object directory containing set of packfile and pack-index pairs")),
 		OPT_END(),
 	};
 
-	if (argc == 2 && !strcmp(argv[1], "-h"))
-		usage_with_options(builtin_multi_pack_index_usage,
-				   builtin_multi_pack_index_options);
-
 	git_config(git_default_config, NULL);
 
 	argc = parse_options(argc, argv, prefix,

@@ -36,11 +32,16 @@ int cmd_multi_pack_index(int argc, const char **argv,
 		opts.object_dir = get_object_directory();
 
 	if (argc == 0)
-		usage_with_options(builtin_multi_pack_index_usage,
-				   builtin_multi_pack_index_options);
+		goto usage;
+
+	if (!strcmp(argv[0], "write")) {
+		if (argc > 1)
+			goto usage;
 
-	if (!strcmp(argv[0], "write"))
 		return write_midx_file(opts.object_dir);
+	}
 
-	return 0;
+usage:
+	usage_with_options(builtin_multi_pack_index_usage,
+			   builtin_multi_pack_index_options);
 }

index 66a7d8e8ea..7f7cdc8b17 100644
@@ -335,12 +335,6 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 	for_each_string_list_item(item, &names) {
 		for (ext = 0; ext < ARRAY_SIZE(exts); ext++) {
 			char *fname, *fname_old;
-			fname = mkpathdup("%s/pack-%s%s", packdir,
-						item->string, exts[ext].name);
-			if (!file_exists(fname)) {
-				free(fname);
-				continue;
-			}
 
 			if (!midx_cleared) {
 				/* if we move a packfile, it will invalidated the midx */

@@ -348,6 +342,13 @@ int cmd_repack(int argc, const char **argv, const char *prefix)
 				midx_cleared = 1;
 			}
 
+			fname = mkpathdup("%s/pack-%s%s", packdir,
+						item->string, exts[ext].name);
+			if (!file_exists(fname)) {
+				free(fname);
+				continue;
+			}
+
 			fname_old = mkpathdup("%s/old-%s%s", packdir,
 						item->string, exts[ext].name);
 			if (file_exists(fname_old))

index d12aa49710..89a107a7f7 100644
@@ -814,7 +814,6 @@ extern char *git_replace_ref_base;
 extern int fsync_object_files;
 extern int core_preload_index;
 extern int core_commit_graph;
-extern int core_multi_pack_index;
 extern int core_apply_sparse_checkout;
 extern int precomposed_unicode;
 extern int protect_hfs;

index 95d8da4243..fbbf0f8e9f 100644
@@ -1313,11 +1313,6 @@ static int git_default_core_config(const char *var, const char *value)
 		return 0;
 	}
 
-	if (!strcmp(var, "core.multipackindex")) {
-		core_multi_pack_index = git_config_bool(var, value);
-		return 0;
-	}
-
 	if (!strcmp(var, "core.sparsecheckout")) {
 		core_apply_sparse_checkout = git_config_bool(var, value);
 		return 0;

index b9bc919cdb..2a6de2330b 100644
@@ -67,7 +67,6 @@ enum object_creation_mode object_creation_mode = OBJECT_CREATION_MODE;
 char *notes_ref_name;
 int grafts_replace_parents = 1;
 int core_commit_graph;
-int core_multi_pack_index;
 int core_apply_sparse_checkout;
 int merge_log_config = -1;
 int precomposed_unicode = -1; /* see probe_utf8_pathname_composition() */

index 8afd08f3fe..19b7df338e 100644
@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "config.h"
 #include "csum-file.h"
 #include "dir.h"
 #include "lockfile.h"

@@ -60,7 +61,6 @@ struct multi_pack_index *load_multi_pack_index(const char *object_dir)
 	midx_size = xsize_t(st.st_size);
 
 	if (midx_size < MIDX_MIN_SIZE) {
-		close(fd);
 		error(_("multi-pack-index file %s is too small"), midx_name);
 		goto cleanup_fail;
 	}

@@ -69,8 +69,7 @@ struct multi_pack_index *load_multi_pack_index(const char *object_dir)
 
 	midx_map = xmmap(NULL, midx_size, PROT_READ, MAP_PRIVATE, fd, 0);
 
-	m = xcalloc(1, sizeof(*m) + strlen(object_dir) + 1);
-	strcpy(m->object_dir, object_dir);
+	FLEX_ALLOC_MEM(m, object_dir, object_dir, strlen(object_dir));
 	m->fd = fd;
 	m->data = midx_map;
 	m->data_len = midx_size;

@@ -171,7 +170,6 @@ struct multi_pack_index *load_multi_pack_index(const char *object_dir)
 	return m;
 
 cleanup_fail:
-	/* no need to check for NULL when freeing */
 	free(m);
 	free(midx_name);
 	if (midx_map)

@@ -324,8 +322,10 @@ int prepare_multi_pack_index_one(struct repository *r, const char *object_dir)
 {
 	struct multi_pack_index *m = r->objects->multi_pack_index;
 	struct multi_pack_index *m_search;
+	int config_value;
 
-	if (!core_multi_pack_index)
+	if (repo_config_get_bool(r, "core.multipackindex", &config_value) ||
+	    !config_value)
 		return 0;
 
 	for (m_search = m; m_search; m_search = m_search->next)

@@ -382,7 +382,8 @@ static void add_pack_to_midx(const char *full_path, size_t full_path_len,
 		ALLOC_GROW(packs->names, packs->nr + 1, packs->alloc_names);
 
 		packs->list[packs->nr] = add_packed_git(full_path,
-							full_path_len, 0);
+							full_path_len,
+							0);
 
 		if (!packs->list[packs->nr]) {
 			warning(_("failed to add packfile '%s'"),

@@ -661,8 +662,8 @@ static size_t write_midx_oid_lookup(struct hashfile *f, unsigned char hash_len,
 			struct pack_midx_entry *next = list;
 			if (oidcmp(&obj->oid, &next->oid) >= 0)
 				BUG("OIDs not in order: %s >= %s",
-				oid_to_hex(&obj->oid),
-				oid_to_hex(&next->oid));
+				    oid_to_hex(&obj->oid),
+				    oid_to_hex(&next->oid));
 		}
 
 		hashwrite(f, obj->oid.hash, (int)hash_len);

index 5a42cbed1d..e3b07f1586 100644
@@ -3,7 +3,31 @@
 
 #include "repository.h"
 
-struct multi_pack_index;
+struct multi_pack_index {
+	struct multi_pack_index *next;
+
+	int fd;
+
+	const unsigned char *data;
+	size_t data_len;
+
+	uint32_t signature;
+	unsigned char version;
+	unsigned char hash_len;
+	unsigned char num_chunks;
+	uint32_t num_packs;
+	uint32_t num_objects;
+
+	const unsigned char *chunk_pack_names;
+	const uint32_t *chunk_oid_fanout;
+	const unsigned char *chunk_oid_lookup;
+	const unsigned char *chunk_object_offsets;
+	const unsigned char *chunk_large_offsets;
+
+	const char **pack_names;
+	struct packed_git **packs;
+	char object_dir[FLEX_ARRAY];
+};
 
 struct multi_pack_index *load_multi_pack_index(const char *object_dir);
 int bsearch_midx(const struct object_id *oid, struct multi_pack_index *m, uint32_t *result);

index 03cc278758..c2b162489a 100644
@@ -84,31 +84,7 @@ struct packed_git {
 	char pack_name[FLEX_ARRAY]; /* more */
 };
 
-struct multi_pack_index {
-	struct multi_pack_index *next;
-
-	int fd;
-
-	const unsigned char *data;
-	size_t data_len;
-
-	uint32_t signature;
-	unsigned char version;
-	unsigned char hash_len;
-	unsigned char num_chunks;
-	uint32_t num_packs;
-	uint32_t num_objects;
-
-	const unsigned char *chunk_pack_names;
-	const uint32_t *chunk_oid_fanout;
-	const unsigned char *chunk_oid_lookup;
-	const unsigned char *chunk_object_offsets;
-	const unsigned char *chunk_large_offsets;
-
-	const char **pack_names;
-	struct packed_git **packs;
-	char object_dir[FLEX_ARRAY];
-};
+struct multi_pack_index;
 
 struct raw_object_store {
 	/*

index 20771d1c1d..8e19972e89 100644
@@ -1,6 +1,3 @@
-/*
- * test-mktemp.c: code to exercise the creation of temporary files
- */
 #include "test-tool.h"
 #include "cache.h"
 #include "midx.h"

@@ -13,7 +10,7 @@ static int read_midx_file(const char *object_dir)
 	struct multi_pack_index *m = load_multi_pack_index(object_dir);
 
 	if (!m)
-		return 0;
+		return 1;
 
 	printf("header: %08x %d %d %d\n",
 	       m->signature,

@@ -24,15 +21,15 @@ static int read_midx_file(const char *object_dir)
 	printf("chunks:");
 
 	if (m->chunk_pack_names)
-		printf(" pack_names");
+		printf(" pack-names");
 	if (m->chunk_oid_fanout)
-		printf(" oid_fanout");
+		printf(" oid-fanout");
 	if (m->chunk_oid_lookup)
-		printf(" oid_lookup");
+		printf(" oid-lookup");
 	if (m->chunk_object_offsets)
-		printf(" object_offsets");
+		printf(" object-offsets");
 	if (m->chunk_large_offsets)
-		printf(" large_offsets");
+		printf(" large-offsets");
 
 	printf("\nnum_objects: %d\n", m->num_objects);
 

@@ -40,7 +37,7 @@ static int read_midx_file(const char *object_dir)
 	for (i = 0; i < m->num_packs; i++)
 		printf("%s\n", m->pack_names[i]);
 
-	printf("object_dir: %s\n", m->object_dir);
+	printf("object-dir: %s\n", m->object_dir);
 
 	return 0;
 }

@@ -48,7 +45,7 @@ static int read_midx_file(const char *object_dir)
 int cmd__read_midx(int argc, const char **argv)
 {
 	if (argc != 2)
-		usage("read-midx <object_dir>");
+		usage("read-midx <object-dir>");
 
 	return read_midx_file(argv[1]);
 }