gbk4_4th_byte
if ( gbk4_4th_byte( (unsigned char) **inbuf )) {
if ( gbk4_4th_byte((unsigned char)**inbuf) ) {
if ( gbk4_4th_byte((unsigned char)**inbuf) ) {
if ( gbk4_4th_byte((unsigned char)**inbuf) ) {
if ( gbk4_4th_byte((unsigned char)**inbuf) ) {
if ( gbk4_4th_byte((unsigned char)**inbuf)) {