[gtk+] Suppress frequent device assertions

[John Ralls <jralls src gnome org>]

commit 46838a2fe2dd94c33792d763e069b5d72987120f
Author: John Ralls <jralls ceridwen us>
Date:   Thu Oct 10 15:24:43 2013 -0700

    Suppress frequent device assertions
    
    Because send crossing event is usually called with a NULL source_device in quartz.

 gdk/gdkwindow.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index f096101..6d2bd68 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -7477,6 +7477,7 @@ send_crossing_event (GdkDisplay                 *display,
 
   if (type == GDK_ENTER_NOTIFY &&
       (pointer_info->need_touch_press_enter ||
+       source_device &&
        gdk_device_get_source (source_device) == GDK_SOURCE_TOUCHSCREEN) &&
       mode != GDK_CROSSING_TOUCH_BEGIN &&
       mode != GDK_CROSSING_TOUCH_END)