Is this a correct fix for the `input-port?' problem?

[Joe Marshall <jrm@packetclustr.com>]

In scsh-package I added `extended-ports' before `scheme' in the
field-reader-package structure:

(define-structure field-reader-package scsh-field-reader-interface
  (open extended-ports
        scheme
        receiving               ; receive
        char-set-package
        scsh-utilities
        error-package           ; error
        scsh-regexp-package
        )
  (files fr))

Is this kosher?