Hello CHICKEN users!
I'm using CHICKEN 4.13.0 from 2017 December. When debugging why "send eof" caused our server to hang indefinitely, I found out that utf8's string-length was the culprit:
```
$ csi
(use utf8)
(string-length "\377\354") ; line that was read from send eof
;; hangs
```
causes the interpreter to hang at least 30 seconds, probably indefinitely. I understand that this string isn't a valid UTF-8 codepoint, but does anyone have suggestions for what to do here? (E.g., "Upgrade to CHICKEN 5" would be a nice answer.)
Some more results that make me think the \377 octal code in particular is culpable:
```
#;4> (string-length "\354 a")
1 ; OK, since \354 isn't a valid UTF-8 char
#;5> (string-length "\366 a")
1
#;6> (string-length "\377 a")
;; Hangs
```
Thank you,
Henry
Infolab Group @ MIT
Cambridge, MA USA