Check for language environments that can't work in unibyte.
(setq language-name "English"))
(if (null (get-language-info language-name 'setup-function))
(error "Language environment not defined: %S" language-name))
+ (unless default-enable-multibyte-characters
+ (or (member (downcase language)
+ '("latin-1" "latin-2" "latin-3" "latin-4" "latin-5"))
+ (error "Language environment `%s' not supported in unibyte mode"))
+ (standard-display-european 1 (downcase language)))
+
(if current-language-environment
(let ((func (get-language-info current-language-environment
'exit-function)))