Subject: problems with string ports and unicode

From: Klaus Stehle <[email-masked]>
Date: Sat, 7 Apr 2012 22:07:01 +0200 (CEST)

Hi,

;;;; a very very short example script to describe the problem:

;; open a string port with unicode characters >= 0x0100
(define p (open-input-string "čtyří"))

Put the line into a script and start guile. You will see the output:
=> Backtrace:

That's all, and guile will hang in an eternal loop.

If you enter the line interactively into the REPL, everything works
properly and you can read all characters with (read-char p).

;;;; another very short script, which is possibly the same problem:

;; open a string port and unread a unicode character >= 0x0100
(define p (open-input-string "ibenik"))
(unread-char #\Š p)

Running these two lines as a script generates an error message:
=> ERROR: In procedure unread-char:
=> ERROR: Throw to key `encoding-error' with args
          `("scm_ungetc" "conversion to port encoding failed" 84 #f #\540)'.

If you enter the lines interactively into the REPL, everything works
properly and you can read all characters with (read-char p).

Cheers,
Klaus Stehle

----------------------------
guile --version
guile (GNU Guile) 2.0.5

uname -srm
Linux 2.6.32-5-amd64 x86_64

echo $LANG
de_DE.UTF-8