; * src/keyboard.c (timer_check_2): Restore run-time conditions.

1 files changed, 19 insertions, 14 deletions

diff --git a/src/keyboard.c b/src/keyboard.c
index f8e6ef748da..4ad6e4e6bd1 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -4645,24 +4645,29 @@ timer_check_2 (Lisp_Object timers, Lisp_Object idle_timers)
           /* If we got here, presumably `decode_timer` has checked
              that this timer has not yet been triggered.  */
           eassert (NILP (AREF (chosen_timer, 0)));
-          specpdl_ref count = SPECPDL_INDEX ();
-          Lisp_Object old_deactivate_mark = Vdeactivate_mark;
+          /* In a production build, where assertions compile to
+             nothing, we still want to play it safe here.  */
+          if (NILP (AREF (chosen_timer, 0)))
+            {
+              specpdl_ref count = SPECPDL_INDEX ();
+              Lisp_Object old_deactivate_mark = Vdeactivate_mark;
 
-          /* Mark the timer as triggered to prevent problems if the lisp
-             code fails to reschedule it right.  */
-          ASET (chosen_timer, 0, Qt);
+              /* Mark the timer as triggered to prevent problems if the lisp
+                 code fails to reschedule it right.  */
+              ASET (chosen_timer, 0, Qt);
 
-          specbind (Qinhibit_quit, Qt);
+              specbind (Qinhibit_quit, Qt);
 
-          call1 (Qtimer_event_handler, chosen_timer);
-          Vdeactivate_mark = old_deactivate_mark;
-          timers_run++;
-          unbind_to (count, Qnil);
+              call1 (Qtimer_event_handler, chosen_timer);
+              Vdeactivate_mark = old_deactivate_mark;
+              timers_run++;
+              unbind_to (count, Qnil);
 
-          /* Since we have handled the event,
-             we don't need to tell the caller to wake up and do it.  */
-          /* But the caller must still wait for the next timer, so
-             return 0 to indicate that.  */
+              /* Since we have handled the event,
+                 we don't need to tell the caller to wake up and do it.  */
+              /* But the caller must still wait for the next timer, so
+                 return 0 to indicate that.  */
+            }
 
           nexttime = make_timespec (0, 0);
           break;