Don't run timers in input-pending-p. Its new check-timers param

provides the prior behavior..
* src/keyboard.c (Finput_pending_p): Accept optional check-timers
param.
* lisp/subr.el (sit-for): Call (input-pending-p t) so as to behave
as before.
* test/automated/timer-tests.el: New file.  Tests that (sit-for 0)
allows another timer to run.

Fixes: debbugs:15045

2 files changed, 14 insertions, 5 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index a0df4425844..0dae87bd69a 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,10 @@
+2013-10-17  Barry O'Reilly  <gundaetiapo@gmail.com>
+
+        Don't run timers in input-pending-p.  Its new check-timers param
+        provides the prior behavior. (Bug#15045).
+        * src/keyboard.c (Finput_pending_p): Accept optional check-timers
+        param.
+
 2013-10-17  Paul Eggert  <eggert@cs.ucla.edu>
 
         Make some functions static in non-Microsoft builds.
diff --git a/src/keyboard.c b/src/keyboard.c
index a776720b807..6b39dfe1019 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -9950,12 +9950,13 @@ requeued_events_pending_p (void)
   return (!NILP (Vunread_command_events));
 }
 
-
-DEFUN ("input-pending-p", Finput_pending_p, Sinput_pending_p, 0, 0, 0,
+DEFUN ("input-pending-p", Finput_pending_p, Sinput_pending_p, 0, 1, 0,
        doc: /* Return t if command input is currently available with no wait.
 Actually, the value is nil only if we can be sure that no input is available;
-if there is a doubt, the value is t.  */)
-  (void)
+if there is a doubt, the value is t.
+
+If CHECK-TIMERS is non-nil, timers that are ready to run will do so.  */)
+  (Lisp_Object check_timers)
 {
   if (!NILP (Vunread_command_events)
       || !NILP (Vunread_post_input_method_events)
@@ -9965,7 +9966,8 @@ if there is a doubt, the value is t.  */)
   /* Process non-user-visible events (Bug#10195).  */
   process_special_events ();
 
-  return (get_input_pending (READABLE_EVENTS_DO_TIMERS_NOW
+  return (get_input_pending ((NILP (check_timers)
+                              ? 0 : READABLE_EVENTS_DO_TIMERS_NOW)
                              | READABLE_EVENTS_FILTER_EVENTS)
           ? Qt : Qnil);
 }