[gnome-boxes] Fix mouse scrollwheel not working

[Marc-Andre Lureau <malureau src gnome org>]

commit ba8b4124dfea34532174cf40952ed7ad3b9e818c
Author: Marc-Andrà Lureau <marcandre lureau gmail com>
Date:   Wed May 9 12:36:42 2012 +0200

    Fix mouse scrollwheel not working
    
    https://bugzilla.gnome.org/show_bug.cgi?id=675615

 src/display-page.vala |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/display-page.vala b/src/display-page.vala
index 52474fa..9f60d92 100644
--- a/src/display-page.vala
+++ b/src/display-page.vala
@@ -79,13 +79,13 @@ private class Boxes.DisplayPage: GLib.Object {
         this.app = app;
 
         event_box = new EventBox ();
-        event_box.set_events (EventMask.POINTER_MOTION_MASK);
+        event_box.set_events (EventMask.POINTER_MOTION_MASK | EventMask.SCROLL_MASK);
         event_box.above_child = true;
         event_box.event.connect ((event) => {
             if (app.fullscreen && event.type == EventType.MOTION_NOTIFY) {
                 var y = event.motion.y;
 
-                if (y == 0) {
+                if (y <= 0) {
                     toolbar_event_stop ();
                     if (event.motion.state == 0)
                         set_overlay_toolbar_visible (true);