* lisp/repeat.el: Fix long-standing problem when a random key activates map

* lisp/repeat.el (repeat-check-key): New defcustom (bug#51390).
(repeat--command-property): New internal function.
(repeat-check-key): New function.
(repeat-post-hook): Use repeat--command-property and repeat-check-key.

* test/lisp/repeat-tests.el (repeat-tests-check-key): New test.

1 files changed, 34 insertions, 0 deletions

diff --git a/test/lisp/repeat-tests.el b/test/lisp/repeat-tests.el
index 76abd24ea2f..02d9ddbc96e 100644
--- a/test/lisp/repeat-tests.el
+++ b/test/lisp/repeat-tests.el
@@ -37,6 +37,8 @@
 (defvar repeat-tests-map
   (let ((map (make-sparse-keymap)))
     (define-key map (kbd "C-x w a") 'repeat-tests-call-a)
+    (define-key map (kbd "M-C-a") 'repeat-tests-call-a)
+    (define-key map (kbd "M-C-z") 'repeat-tests-call-a)
     map)
   "Keymap for keys that initiate repeating sequences.")
 
@@ -70,6 +72,38 @@
   ;; Check for self-inserting keys
   (should (equal (buffer-string) inserted)))
 
+(ert-deftest repeat-tests-check-key ()
+  (with-repeat-mode
+   (let ((repeat-echo-function 'ignore))
+     (let ((repeat-check-key t))
+       (repeat-tests--check
+        "C-x w a b a c"
+        '((1 a) (1 b) (1 a)) "c")
+       (repeat-tests--check
+        "M-C-a b a c"
+        '((1 a) (1 b) (1 a)) "c")
+       (repeat-tests--check
+        "M-C-z b a c"
+        '((1 a)) "bac")
+       (unwind-protect
+           (progn
+             (put 'repeat-tests-call-a 'repeat-check-key 'no)
+             (repeat-tests--check
+              "M-C-z b a c"
+              '((1 a) (1 b) (1 a)) "c"))
+         (put 'repeat-tests-call-a 'repeat-check-key nil)))
+     (let ((repeat-check-key nil))
+       (repeat-tests--check
+        "M-C-z b a c"
+        '((1 a) (1 b) (1 a)) "c")
+       (unwind-protect
+           (progn
+             (put 'repeat-tests-call-a 'repeat-check-key t)
+             (repeat-tests--check
+              "M-C-z b a c"
+              '((1 a)) "bac"))
+         (put 'repeat-tests-call-a 'repeat-check-key nil))))))
+
 (ert-deftest repeat-tests-exit-key ()
   (with-repeat-mode
    (let ((repeat-echo-function 'ignore))