extern int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
int nr_refspec, char **refspec, int all);
extern int get_ack(int fd, unsigned char *result_sha1);
extern int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
int nr_refspec, char **refspec, int all);
extern int get_ack(int fd, unsigned char *result_sha1);