if (c0.has_first_timestamp()) {
c.set_first_timestamp(c0.first_timestamp());
}
+ c.set_pgn_file_num(c0.pgn_file_num());
c.set_pgn_start_position(c0.pgn_start_position());
} else {
c.set_opening_num(c1.opening_num());
if (c1.has_first_timestamp()) {
c.set_first_timestamp(c1.first_timestamp());
}
+ c.set_pgn_file_num(c1.pgn_file_num());
c.set_pgn_start_position(c1.pgn_start_position());
}