(add-to-ordered-list): Test membership with eq. Simplify.

diff --git a/lisp/subr.el b/lisp/subr.el
index f913e984b888ee097317fdf4fb661151848e05ef..f0b8f9e96a7c4c68154ad6d3465e1fe096c35716 100644 (file)
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -960,12 +960,11 @@ other hooks, such as major mode hooks, can do the job."
 
 (defun add-to-ordered-list (list-var element &optional order)
   "Add to the value of LIST-VAR the element ELEMENT if it isn't there yet.
-The test for presence of ELEMENT is done with `equal'.
+The test for presence of ELEMENT is done with `eq'.
 
 The resulting list is reordered so that the elements are in the
-order given by each element's numeric list order.
-Elements without a numeric list order are placed at the end of
-the list.
+order given by each element's numeric list order.  Elements
+without a numeric list order are placed at the end of the list.
 
 If the third optional argument ORDER is non-nil, set the
 element's list order to the given value.
@@ -979,16 +978,16 @@ The return value is the new value of LIST-VAR."
       (put list-var 'list-order
            (setq ordering (make-hash-table :weakness 'key :test 'eq))))
     (when order
-      (puthash element order ordering))
-    (add-to-list list-var element)
+      (puthash element (and (numberp order) order) ordering))
+    (unless (memq element (symbol-value list-var))
+      (set list-var (cons element (symbol-value list-var))))
     (set list-var (sort (symbol-value list-var)
                        (lambda (a b)
                          (let ((oa (gethash a ordering))
                                (ob (gethash b ordering)))
-                           (cond
-                            ((not oa) nil)
-                            ((not ob) t)
-                            (t (< oa ob)))))))))
+                           (if (and oa ob)
+                               (< oa ob)
+                             oa)))))))
 
 \f
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