sha1_object_info: examine cached_object store too

Cached object store was added in d66b37b (Add pretend_sha1_file()
interface. - 2007-02-04) as a way to temporarily inject some objects
to object store.

But only read_sha1_file() knows about this store. While it will return
an object from this store, sha1_object_info() will happily say
"object not found".

Teach sha1_object_info() about the cached store for consistency.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

sha1_file.c

@@ -2020,9 +2020,17 @@ static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *size
 
 int sha1_object_info(const unsigned char *sha1, unsigned long *sizep)
 {
+	struct cached_object *co;
 	struct pack_entry e;
 	int status;
 
+	co = find_cached_object(sha1);
+	if (co) {
+		if (sizep)
+			*sizep = co->size;
+		return co->type;
+	}
+
 	if (!find_pack_entry(sha1, &e)) {
 		/* Most likely it's a loose object. */
 		status = sha1_loose_object_info(sha1, sizep);