1 files changed, 23 insertions, 8 deletions

diff --git a/lisp/international/quail.el b/lisp/international/quail.el
index c36f022796d..995ce40fd84 100644
--- a/lisp/international/quail.el
+++ b/lisp/international/quail.el
@@ -1637,16 +1637,31 @@ All possible translations of the current key and whole possible longer keys
  are shown."
   (interactive)
   (quail-setup-completion-buf)
-  (let ((key quail-current-key)
-        (map (quail-lookup-key quail-current-key)))
+  (let ((win (get-buffer-window quail-completion-buf 'visible))
+        (key quail-current-key)
+        (map (quail-lookup-key quail-current-key))
+        (require-update nil))
     (save-excursion
       (set-buffer quail-completion-buf)
-      (erase-buffer)
-      (insert "Possible completion and corresponding translations are:\n")
-      (quail-completion-1 key map 1)
-      (goto-char (point-min))
-      (display-buffer (current-buffer)))
-      (quail-update-guidance)))
+      (if (and win
+               (equal key quail-current-key)
+               (eq last-command 'quail-completion))
+          ;; The window for Quail completion buffer has already been
+          ;; shown.  We just scroll it appropriately.
+          (if (pos-visible-in-window-p (point-max) win)
+              (set-window-start win (point-min))
+            (let ((other-window-scroll-buffer quail-completion-buf))
+              (scroll-other-window)))
+        (setq quail-current-key key)
+        (erase-buffer)
+        (insert "Possible completion and corresponding translations are:\n")
+        (quail-completion-1 key map 1)
+        (goto-char (point-min))
+        (display-buffer (current-buffer))
+        (setq require-update t)))
+    (if require-update
+        (quail-update-guidance)))
+  (setq this-command 'quail-completion))
 
 ;; List all completions of KEY in MAP with indentation INDENT.
 (defun quail-completion-1 (key map indent)