Subject: 28.0.60; repeat-mode issues

From: Juri Linkov <[email-masked]>
Date: Tue, 19 Oct 2021 10:12:20 +0300

Tags: patch

Currently there is a bug where the prefix arg changed for the repeatable
commands, is applied to the next non-repeatable command.  For example:

  C-- C-x o o C-n
or
  C-x o C-- o C-n

`C-n' moves up, not down.  This patch fixes this bug:

diff --git a/lisp/repeat.el b/lisp/repeat.el
index ee9e14b515..f4526c20f4 100644
--- a/lisp/repeat.el
+++ b/lisp/repeat.el
@@ -390,7 +390,10 @@ repeat-mode
 See `describe-repeat-maps' for a list of all repeatable command."
   :global t :group 'convenience
   (if (not repeat-mode)
-      (remove-hook 'post-command-hook 'repeat-post-hook)
+      (progn
+        (remove-hook 'pre-command-hook 'repeat-pre-hook)
+        (remove-hook 'post-command-hook 'repeat-post-hook))
+    (add-hook 'pre-command-hook 'repeat-pre-hook)
     (add-hook 'post-command-hook 'repeat-post-hook)
     (let* ((keymaps nil)
            (commands (all-completions
@@ -402,27 +405,60 @@ repeat-mode
                (length commands)
                (length (delete-dups keymaps))))))
 
-(defun repeat-post-hook ()
-  "Function run after commands to set transient keymap for repeatable keys."
-  (let ((was-in-progress repeat-in-progress))
-    (setq repeat-in-progress nil)
+(defun repeat-map ()
+  "Return a map for keys repeatable after the current command."
   (when repeat-mode
     (let ((rep-map (or repeat-map
                        (and (symbolp real-this-command)
                             (get real-this-command 'repeat-map)))))
       (when rep-map
-          (when (boundp rep-map)
+        (when (and (symbolp rep-map) (boundp rep-map))
           (setq rep-map (symbol-value rep-map)))
-          (let ((map (copy-keymap rep-map)))
 
+        (if repeat-exit-key
+            ;; `repeat-exit-key' modifies the map by adding keys
+            (copy-keymap rep-map)
+          rep-map)))))
+
+(defun repeat-map-valid (map)
+  "Check if MAP can be used for the next command.
+Can contain more conditions."
+  (and map
+       ;; Avoid using repeatable keys when minibuffer prompt pops up
+       (zerop (minibuffer-depth))
        ;; Exit when the last char is not among repeatable keys,
        ;; so e.g. `C-x u u' repeats undo, whereas `C-/ u' doesn't.
-            (when (and (zerop (minibuffer-depth)) ; avoid remapping in prompts
-                       (or (lookup-key map (this-command-keys-vector))
-                           prefix-arg))
+       (or (lookup-key map (vector last-nonmenu-event))
+           ;; `prefix-arg' can affect next repeatable commands
+           ;; (and repeat-keep-prefix prefix-arg)
+           )))
+
+(defun repeat-pre-hook ()
+  "Function run before commands to handle repeatable keys."
+  ;; Reset prefix-arg before the next non-repeatable command,
+  ;; e.g. `C-- C-x o o C-n' or `C-x o C-- o C-n', so `C-n'
+  ;; should not use `prefix-arg' to go in opposite direction.
+  (when (and repeat-keep-prefix prefix-arg repeat-in-progress)
+    (let ((map (repeat-map)))
+      (if map
+          ;; Optimize to use less logic in `repeat-map'
+          ;; when called again from `repeat-post-hook'
+          (setq repeat-map map)
+        ;; When `repeat-post-hook' will exit the repeatable sequence,
+        ;; this means the current command is not repeatable,
+        ;; so reset `prefix-arg' enabled for repeatable commands only.
+        (setq prefix-arg nil)))))
+
+(defun repeat-post-hook ()
+  "Function run after commands to set transient keymap for repeatable keys."
+  (let ((was-in-progress repeat-in-progress))
+    (setq repeat-in-progress nil)
+
+    (let ((map (repeat-map)))
+      (when (repeat-map-valid map)
 
         ;; Messaging
-              (unless prefix-arg
+        (unless prefix-arg ;; Don't overwrite prefix arg echo
           (funcall repeat-echo-function map))
 
         ;; Adding an exit key
@@ -446,7 +482,7 @@ repeat-post-hook
                    (lambda ()
                      (setq repeat-in-progress nil)
                      (funcall exitfun)
-                           (funcall repeat-echo-function nil)))))))))))
+                     (funcall repeat-echo-function nil))))))))
 
     (setq repeat-map nil)
     (when (and was-in-progress (not repeat-in-progress))