[gtk+/gtk-3-8] xi2: Reset scroll valuators on synthesized crossing events

[Paolo Borelli <pborelli src gnome org>]

commit 8e56a8097230c006832cbc195fd56c87884ac7ab
Author: Carlos Garnacho <carlosg gnome org>
Date:   Thu Mar 28 14:57:00 2013 +0100

    xi2: Reset scroll valuators on synthesized crossing events
    
    On crossing events resulting from moving windows (eg. workspace switch),
    deviceid equals sourceid, so make those reset scroll valuators on all
    slave devices to avoid misleading jumps in scroll events
    
    Fixes https://bugzilla.gnome.org/show_bug.cgi?id=690275

 gdk/x11/gdkdevicemanager-xi2.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)
---
diff --git a/gdk/x11/gdkdevicemanager-xi2.c b/gdk/x11/gdkdevicemanager-xi2.c
index 660d0f0..db2ba28 100644
--- a/gdk/x11/gdkdevicemanager-xi2.c
+++ b/gdk/x11/gdkdevicemanager-xi2.c
@@ -1555,7 +1555,20 @@ gdk_x11_device_manager_xi2_translate_event (GdkEventTranslator *translator,
         source_device = g_hash_table_lookup (device_manager->id_table,
                                              GUINT_TO_POINTER (xev->sourceid));
         gdk_event_set_source_device (event, source_device);
-        _gdk_device_xi2_reset_scroll_valuators (GDK_X11_DEVICE_XI2 (source_device));
+
+       if (gdk_device_get_device_type (source_device) != GDK_DEVICE_TYPE_MASTER)
+          _gdk_device_xi2_reset_scroll_valuators (GDK_X11_DEVICE_XI2 (source_device));
+        else
+          {
+            GList *slaves, *l;
+
+            slaves = gdk_device_list_slave_devices (source_device);
+
+            for (l = slaves; l; l = l->next)
+              _gdk_device_xi2_reset_scroll_valuators (GDK_X11_DEVICE_XI2 (l->data));
+
+            g_list_free (slaves);
+          }
 
         event->crossing.mode = translate_crossing_mode (xev->mode);
         event->crossing.detail = translate_notify_type (xev->detail);