(compose-chars-component): Signal

error if CH is a rule-based composition character.
(compose-chars): Signal error if an already compsed character is
going to be composed by rule-base.

diff --git a/lisp/international/mule-util.el b/lisp/international/mule-util.el
index 7e237a6ea5634b6144b97ad996a997dff0e0ea9b..a366123ec253abb4c781c26de9f32cd309cc00d1 100644 (file)
--- a/lisp/international/mule-util.el
+++ b/lisp/international/mule-util.el
@@ -470,7 +470,9 @@ overall glyph is updated as follows:
       (format "\240%c" (+ ch 128))
     (let ((str (string-as-unibyte (char-to-string ch))))
       (if (cmpcharp ch)
-         (substring str (if (= (aref str 1) ?\xFF) 2 1))
+         (if (= (aref str 1) ?\xFF)
+             (error "Can't compose a rule-based composition character")
+           (substring str (if (= (aref str 1) ?\xFF) 2 1)))
        (aset str 0 (+ (aref str 0) ?\x20))
        str))))
 
@@ -493,12 +495,17 @@ See the documentation of `reference-point-alist' for more detail."
     (let* ((with-rule (consp (car args)))
           (str (if with-rule (concat (vector leading-code-composition ?\xFF))
                  (char-to-string leading-code-composition))))
+      (if (and with-rule
+              (cmpcharp first-component))
+         (error "Can't compose an already composed character"))
       (setq str (concat str (compose-chars-component first-component)))
       (while args
        (if with-rule
            (progn
              (if (not (consp (car args)))
                  (error "Invalid composition rule: %s" (car args)))
+             (if (cmpcharp (car (cdr args)))
+                 (error "Can't compose an already composed character"))
              (setq str (concat str (compose-chars-rule (car args))
                                (compose-chars-component (car (cdr args))))
                    args (cdr (cdr args))))