[gtk+] Don't compress motion events for different devices

[Owen Taylor <otaylor src gnome org>]

commit e2705544ab73434455e0837fc5702f6c6881ad85
Author: Owen W. Taylor <otaylor fishsoup net>
Date:   Thu Feb 14 14:51:33 2013 -0500

    Don't compress motion events for different devices
    
    A switch of device may be significant for an application, so don't
    compress motion events if they are for different devices. This simple
    handling isn't sufficient if we have competing event streams from
    two different pointer events, but we don't expect this case to be
    common.

 gdk/gdkevents.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)
---
diff --git a/gdk/gdkevents.c b/gdk/gdkevents.c
index 8e05a8e..4a9d0b9 100644
--- a/gdk/gdkevents.c
+++ b/gdk/gdkevents.c
@@ -268,6 +268,7 @@ _gdk_event_queue_handle_motion_compression (GdkDisplay *display)
   GList *tmp_list;
   GList *pending_motions = NULL;
   GdkWindow *pending_motion_window = NULL;
+  GdkDevice *pending_motion_device = NULL;
 
   /* If the last N events in the event queue are motion notify
    * events for the same window, drop all but the last */
@@ -288,7 +289,12 @@ _gdk_event_queue_handle_motion_compression (GdkDisplay *display)
           pending_motion_window != event->event.motion.window)
         break;
 
+      if (pending_motion_device != NULL &&
+          pending_motion_device != event->event.motion.device)
+        break;
+
       pending_motion_window = event->event.motion.window;
+      pending_motion_device = event->event.motion.device;
       pending_motions = tmp_list;
 
       tmp_list = tmp_list->prev;