playing with invalid chars / reader errors and the repl

Hi,

something is strange with the handling of invalid chars in the repl.

Example session:

This part works as expected:
,----
| gosh$ (gauche-version)
| "0.9.15"
| gosh$ "aabb"1"dd"
| "aabb"
| 1
| "dd"
`----

This is strange:
,----
| gosh$ "aa\Uffffffffbb"1"dd"
| *** ERROR: bad character code: -1
| Stack Trace:
| _______________________________________
|   0  (report-error e)
|   1  (reader buffer)
|         at "/usr/local/share/gauche-0.98/0.9.15/lib/gauche/interactive/editable-reader.scm":69
|   2  (read)
|         at "/usr/local/share/gauche-0.98/0.9.15/lib/gauche/interactive.scm":303
|   3  (reader)
|   4  (with-error-handler (^e (report-error e) #t) (^ () (let loop2 ...
| "1"
| *** UNBOUND-VARIABLE-ERROR: unbound variable: dd
| Stack Trace:
| _______________________________________
|   0  (report-error e)
|   1  (eval expr env)
|         at "/usr/local/share/gauche-0.98/0.9.15/lib/gauche/interactive.scm":359
|   2  (evaluator exp (vm-current-module))
|   3  (with-error-handler (^e (report-error e) #t) (^ () (let loop2 ...
| *** READ-ERROR: Read error at "(input string port)":line 2: EOF encountered in a string literal: "\n"
| Stack Trace:
| _______________________________________
|   0  (report-error e)
|   1  (reader buffer)
|         at "/usr/local/share/gauche-0.98/0.9.15/lib/gauche/interactive/editable-reader.scm":69
|   2  (read)
|         at "/usr/local/share/gauche-0.98/0.9.15/lib/gauche/interactive.scm":303
|   3  (reader)
|   4  (with-error-handler (^e (report-error e) #t) (^ () (let loop2 ...
`----

greetings
jens