merge(third_party/git): Merge squashed git subtree at v2.23.0

Merge commit '1b593e1ea4' as 'third_party/git'

third_party/git/t/helper/test-read-midx.c

@@ -0,0 +1,51 @@
+#include "test-tool.h"
+#include "cache.h"
+#include "midx.h"
+#include "repository.h"
+#include "object-store.h"
+
+static int read_midx_file(const char *object_dir)
+{
+	uint32_t i;
+	struct multi_pack_index *m = load_multi_pack_index(object_dir, 1);
+
+	if (!m)
+		return 1;
+
+	printf("header: %08x %d %d %d\n",
+	       m->signature,
+	       m->version,
+	       m->num_chunks,
+	       m->num_packs);
+
+	printf("chunks:");
+
+	if (m->chunk_pack_names)
+		printf(" pack-names");
+	if (m->chunk_oid_fanout)
+		printf(" oid-fanout");
+	if (m->chunk_oid_lookup)
+		printf(" oid-lookup");
+	if (m->chunk_object_offsets)
+		printf(" object-offsets");
+	if (m->chunk_large_offsets)
+		printf(" large-offsets");
+
+	printf("\nnum_objects: %d\n", m->num_objects);
+
+	printf("packs:\n");
+	for (i = 0; i < m->num_packs; i++)
+		printf("%s\n", m->pack_names[i]);
+
+	printf("object-dir: %s\n", m->object_dir);
+
+	return 0;
+}
+
+int cmd__read_midx(int argc, const char **argv)
+{
+	if (argc != 2)
+		usage("read-midx <object-dir>");
+
+	return read_midx_file(argv[1]);
+}