bug#62690: Guile 3.0.9 (read-u8) defaults to current-output-port

[Rui Zhang]

Reproduction:

scheme@(guile-user)> (import (scheme base))
scheme@(guile-user)> (read-u8)
ice-9/boot-9.scm:1685:16: In procedure raise-exception:
In procedure get-u8: Wrong type argument in position 1 (expecting open input 
port): #<output: file /dev/pts/9>

Expected: (read-u8) should read a byte from the input port, not the output port.

In scheme/base.scm:

(define* (read-u8 #:optional (port (current-output-port)))
  (get-u8 port))

I think this is a typo, where current-output-port should be current-input-port?

-Rui