Only disable 'completion-preview-active-mode' when it is on

* lisp/completion-preview.el
(completion-preview--post-command): Avoid calling
'completion-preview-active-mode' to disable the mode when
already off, since it forces a costly redisplay. (Bug#76964)

(cherry picked from commit b6b4a080a3abb5a45b680e26f93dd17adbb75f69)

diff --git a/lisp/completion-preview.el b/lisp/completion-preview.el
index e4bbb3165c1a093aa7667ee6bfe73ab46f740be3..9f5024c9a89aee9f2b107e52f0a7cdca73c11c41 100644 (file)
--- a/lisp/completion-preview.el
+++ b/lisp/completion-preview.el
@@ -663,12 +663,17 @@ point, otherwise hide it."
 
     ;; If we're called after a command that itself updates the
     ;; preview, don't do anything.
-    (unless internal-p
-      (if (and (completion-preview-require-certain-commands)
-               (completion-preview-require-minimum-symbol-length)
-               (not buffer-read-only))
-          (completion-preview--show)
-        (completion-preview-hide)))))
+    (cond
+     (internal-p
+      ;; `this-command' took care of updating the preview.  Do nothing.
+      )
+     ((and (completion-preview-require-certain-commands)
+           (completion-preview-require-minimum-symbol-length))
+      ;; All conditions met.  Show or update the preview.
+      (completion-preview--show))
+     (completion-preview-active-mode
+      ;; The preview is shown, but it shouldn't be.  Hide it.
+      (completion-preview-hide)))))
 
 (defun completion-preview--barf-if-no-preview ()
   "Signal a `user-error' if completion preview is not active."