[gtk] x11: don't add unknown tools to our list

[Carlos Garnacho <carlosg src gnome org>]

commit e95e0458988821ce4d8915c243fa79398515ed27
Author: Peter Hutterer <peter hutterer who-t net>
Date:   Fri Dec 14 14:57:26 2018 +1000

    x11: don't add unknown tools to our list
    
    Generic tools (Bamboo, built-in tablets) always have the same serial number
    assigned by the wacom driver. This includes the touch tool when the wacom
    driver handles the touch evdev node (common where users require the wacom
    gestures to work).
    
    When the first device is the touch device, a tool is created with that serial.
    All future tools now return the touch tool on lookup since they all share the
    same serial number. Worse, this happens *across* devices, so the pen
    event node gets assigned the touch tool because they all have the same serial.
    
    Since we don't actually care about the touch as a tool, let's skip any unknown
    tool. This captures pads as well.

 gdk/x11/gdkdevicemanager-xi2.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/gdk/x11/gdkdevicemanager-xi2.c b/gdk/x11/gdkdevicemanager-xi2.c
index 413918ec41..8c1cc41a70 100644
--- a/gdk/x11/gdkdevicemanager-xi2.c
+++ b/gdk/x11/gdkdevicemanager-xi2.c
@@ -1103,8 +1103,11 @@ handle_property_change (GdkX11DeviceManagerXI2 *device_manager,
               GdkDeviceToolType tool_type;
 
               tool_type = device_get_tool_type (device);
-              tool = gdk_device_tool_new (serial_id, tool_id, tool_type, 0);
-              gdk_seat_default_add_tool (GDK_SEAT_DEFAULT (seat), tool);
+              if (tool_type != GDK_DEVICE_TOOL_TYPE_UNKNOWN)
+                {
+                  tool = gdk_device_tool_new (serial_id, tool_id, tool_type, 0);
+                  gdk_seat_default_add_tool (GDK_SEAT_DEFAULT (seat), tool);
+                }
             }
         }