when GBK but utf-8-alike codepoints such as "哦" "强" appear in 1 line message (without other non-utf-8-alike codepoint), the display is broken.
locale/Script: GB2312 (GBK indeed) (default by system)
utf-8 display: on (default by installtion)
utf-8 encode/outgoing: off (default by installtion)
font: 宋体 ("songti", simsun.ttf)
reproduce steps:
1. run tcpdump on port 6667
2. connect server
3. //query $me
4. check he output of tcpdump, the character is not encoded into utf-8 before send via tcp, and is same recv from server: *Right* behavior
5. say "哦" ( //say $chr(197) $+ (182) ) then enter -> the character is unreadable too *BAD*
6. the character is sent back to myself -> still unreadble character too *BAD*
7. turn "utf-8 display" off and the character is back normal again, no problem.
now i'd guess the problem is "哦" is $chr(197) $+ (182) in GBK, which is treated as non-Chinese character in UTF-8 when displaying

a string that "$isutf() and can be $utfdecode()" may not be display in specified font/script
solution: just use the origin text instead unless the decoded text can be display correctly in specified font/script