(display-time-event-handler): If Don't run the timer

for successive times that are already in the past.

1 files changed, 17 insertions, 1 deletions

diff --git a/lisp/time.el b/lisp/time.el
index 9d418d4f8f7..d400d75ff37 100644
--- a/lisp/time.el
+++ b/lisp/time.el
@@ -134,7 +134,23 @@ would give mode line times like `94/12/30 21:07:48 (UTC)'.")
 (defun display-time-event-handler ()
   (display-time-update)
   ;; Do redisplay right now, if no input pending.
-  (sit-for 0))
+  (sit-for 0)
+  (let ((current (current-time))
+        (timer display-time-timer))
+    ;; If the next activation time is already in the past,
+    ;; skip executions until we reach a time in the future.
+    ;; This avoids a long pause if Emacs has been suspended for hours.
+    (or (> (aref timer 1) (nth 0 current))
+        (and (= (aref timer 1) (nth 0 current))
+             (> (aref timer 2) (nth 1 current)))
+        (and (= (aref timer 1) (nth 0 current))
+             (= (aref timer 2) (nth 1 current))
+             (> (aref timer 3) (nth 2 current)))
+        (progn
+          (cancel-timer timer)
+          (timer-set-time timer (timer-next-integral-multiple-of-time
+                                 current display-time-interval))
+          (timer-activate timer)))))
 
 ;; Update the display-time info for the mode line
 ;; but don't redisplay right now.  This is used for