1 files changed, 35 insertions, 6 deletions

diff --git a/lisp/simple.el b/lisp/simple.el
index 7e4a1a4adfe..6ac05b42179 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -484,7 +484,15 @@ and the greater of them is not at the start of a line."
 
 (defun what-cursor-position (&optional detail)
   "Print info on cursor position (on screen and within buffer).
-With prefix argument, print detailed info of a character on cursor position."
+With prefix argument, print detailed info of a character on cursor position.
+
+For the detailed information, Emacs internal character code, Emacs
+internal character components (the character set name and position
+code(s)), and the corresponding external character components (the
+external character set name and external character code(s)) are shown
+in this order.
+
+Each language environment may show different external character components."
   (interactive "P")
   (let* ((char (following-char))
          (beg (point-min))
@@ -505,18 +513,39 @@ With prefix argument, print detailed info of a character on cursor position."
                      pos total percent beg end col hscroll)
           (message "point=%d of %d(%d%%)  column %d %s"
                    pos total percent col hscroll))
-      (let ((str (if detail (format " %s" (split-char char)) "")))
+      (if detail
+          (let* ((internal (split-char char))
+                 (charset (char-charset char))
+                 (slot (assq charset charset-origin-alist))
+                 external)
+            (if slot
+                (setq external (list (nth 1 slot) (funcall (nth 2 slot) char)))
+              (if (eq charset 'composition)
+                  (setq internal '("composite-character"))
+                (setq external (cons (charset-short-name charset)
+                                     (copy-sequence (cdr internal))))
+                (if (= (charset-iso-graphic-plane charset) 1)
+                    (progn
+                      (setcar (cdr external) (+ (nth 1 external) 128))
+                      (if (nth 2 external)
+                          (setcar (nthcdr 2 external)
+                                  (+ (nth 2 external) 128)))))))
+            (message "Char: %s (0%o, %d, 0x%x) %s %s"
+                     (if (< char 256)
+                         (single-key-description char)
+                       (char-to-string char))
+                     char char char (or internal "") (or external "")))
         (if (or (/= beg 1) (/= end (1+ total)))
-            (message "Char: %s (0%o, %d, 0x%x) %s point=%d of %d(%d%%) <%d - %d>  column %d %s"
+            (message "Char: %s (0%o, %d, 0x%x) point=%d of %d(%d%%) <%d - %d>  column %d %s"
                      (if (< char 256)
                          (single-key-description char)
                        (char-to-string char))
-                     char char char str pos total percent beg end col hscroll)
-          (message "Char: %s (0%o, %d, 0x%x)%s point=%d of %d(%d%%)  column %d %s"
+                     char char char pos total percent beg end col hscroll)
+          (message "Char: %s (0%o, %d, 0x%x) point=%d of %d(%d%%)  column %d %s"
                    (if (< char 256)
                        (single-key-description char)
                      (char-to-string char))
-                   char char char str pos total percent col hscroll))))))
+                   char char char pos total percent col hscroll))))))
 
 (defun fundamental-mode ()
   "Major mode not specialized for anything in particular.