Ignore BUFFER_SWITCH_EVENT events for the purposes of input-pending-p.

src/keyboard.c (readable_events): When FLAGS include
 READABLE_EVENTS_FILTER_EVENTS, ignore BUFFER_SWITCH_EVENT events.
 This avoids returning non-nil from input-pending-p when only such
 events are in the queue.

Fixes: debbugs:18856

src/ChangeLog

@@ -1,3 +1,10 @@
+2014-11-01  Eli Zaretskii  <eliz@gnu.org>
+
+	* keyboard.c (readable_events): When FLAGS include
+	READABLE_EVENTS_FILTER_EVENTS, ignore BUFFER_SWITCH_EVENT events.
+	This avoids returning non-nil from input-pending-p when only such
+	events are in the queue.  (Bug#18856)
+
 2014-11-01  Jan Djärv  <jan.h.d@swipnet.se>
 
 	* nsselect.m (QCLIPBOARD, QSECONDARY, QTEXT, QFILE_NAME)

src/keyboard.c

@@ -3495,7 +3495,8 @@ readable_events (int flags)
 		       && event->part == scroll_bar_handle
 		       && event->modifiers == 0)
 #endif
-		  )
+		  && !((flags & READABLE_EVENTS_FILTER_EVENTS)
+		       && event->kind == BUFFER_SWITCH_EVENT))
 		return 1;
 	      event++;
               if (event == kbd_buffer + KBD_BUFFER_SIZE)