extern struct child_process *git_connect(int fd[2], const char *url, const char *prog, int flags);
extern int finish_connect(struct child_process *conn);
extern int path_match(const char *path, int nr, char **match);
-extern int get_ack(int fd, unsigned char *result_sha1);
struct extra_have_objects {
int nr, alloc;
unsigned char (*array)[20];