Don't register a coding system into

non-iso-charset-alist more than once.
(cp-make-coding-system): Likewise.

1 files changed, 20 insertions, 14 deletions

diff --git a/lisp/international/code-pages.el b/lisp/international/code-pages.el
index 73c953a2fe4..c70388ba4c9 100644
--- a/lisp/international/code-pages.el
+++ b/lisp/international/code-pages.el
@@ -193,15 +193,18 @@ Return an updated `non-iso-charset-alist'."
               ;; a separate table that only translates the coding
               ;; system's safe-chars.
               (cons 'translation-table-for-input 'ucs-mule-to-mule-unicode)))
-       (push (list ',name
-                   nil                  ; charset list
-                   ',decoder
-                   (let (l)             ; code range
-                     (dolist (elt (reverse codes))
-                       (push (cdr elt) l)
-                       (push (car elt) l))
-                     (list l)))
-             non-iso-charset-alist))))
+       (let ((slot (assq ',name non-iso-charset-alist))
+             (elt (list nil                     ; charset list
+                        ',decoder
+                        (let (l)                ; code range
+                          (dolist (elt (reverse codes))
+                            (push (cdr elt) l)
+                            (push (car elt) l))
+                          (list l)))))
+         (if (not slot)
+             (push (cons ',name elt) non-iso-charset-alist)
+           (setcdr slot elt)
+           non-iso-charset-alist)))))
 
 (eval-when-compile (defvar non-iso-charset-alist))
 
@@ -4502,11 +4505,14 @@ Return an updated `non-iso-charset-alist'."
     ;; Define cp125* as aliases for all windows-125*, so on Windows
     ;; we can just concat "cp" to the ANSI codepage we get from the system
     ;; and not have to worry about whether it should be "cp" or "windows-".
-    (if (coding-system-p w)
-        (define-coding-system-alias c w))
-    ;; Compatibility with codepage.el, though cp... are not the
-    ;; canonical names.
-    (push (assoc w non-iso-charset-alist) non-iso-charset-alist)))
+    (when (coding-system-p w)
+      (define-coding-system-alias c w)
+      ;; Compatibility with codepage.el, though cp... are not the
+      ;; canonical names.
+      (if (not (assq c non-iso-charset-alist))
+          (let ((slot (assq w non-iso-charset-alist)))
+            (if slot
+                (push (cons c (cdr slot)) non-iso-charset-alist)))))))
 
 (provide 'code-pages)