(add-to-list): Optimize if compare-fn is `eq' or `eql'.

(sit-for): If last command was a prefix arg, add the read-ahead
event to unread-command-events as (t . EVENT) so it will be added
to this-command-keys by read-key-sequence.

1 files changed, 21 insertions, 9 deletions

diff --git a/lisp/subr.el b/lisp/subr.el
index 1f874be60e0..957d098703f 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -1100,13 +1100,19 @@ until a certain package is loaded, you should put the call to `add-to-list'
 into a hook function that will be run only after loading the package.
 `eval-after-load' provides one way to do this.  In some cases
 other hooks, such as major mode hooks, can do the job."
-  (if (if compare-fn
-          (let (present)
-            (dolist (elt (symbol-value list-var))
-              (if (funcall compare-fn element elt)
-                  (setq present t)))
-            present)
-        (member element (symbol-value list-var)))
+  (if (cond
+       ((eq compare-fn 'eq)
+        (memq element (symbol-value list-var)))
+       ((eq compare-fn 'eql)
+        (memql element (symbol-value list-var)))
+       (compare-fn
+        (let (present)
+          (dolist (elt (symbol-value list-var))
+            (if (funcall compare-fn element elt)
+                (setq present t)))
+          present))
+       (t
+        (member element (symbol-value list-var))))
       (symbol-value list-var)
     (set list-var
          (if append
@@ -1752,8 +1758,14 @@ floating point support.
     (or nodisp (redisplay))
     (let ((read (read-event nil nil seconds)))
       (or (null read)
-          (progn (push read unread-command-events)
-                 nil))))))
+          (progn
+            ;; If last command was a prefix arg, e.g. C-u, push this event onto
+            ;; unread-command-events as (t . EVENT) so it will be added to
+            ;; this-command-keys by read-key-sequence.
+            (if (eq overriding-terminal-local-map universal-argument-map)
+                (setq read (cons t read)))
+            (push read unread-command-events)
+            nil))))))
 
 ;;; Atomic change groups.