valid_gbk_head    319 ext/mysqlnd/mysqlnd_charset.c 	return (valid_gbk_head(start[0]) && (end) - (start) > 1 && valid_gbk_tail(start[1])) ? 2 : 0;
valid_gbk_head    324 ext/mysqlnd/mysqlnd_charset.c 	return (valid_gbk_head(gbk) ? 2 : 1);