eventcomm: ignore fake and broken MT devices

An MT device without X/Y is not a touchpad. And neither are fake MT devices.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

src/eventcomm.c

@@ -325,6 +325,15 @@ event_query_is_touchpad(struct libevdev *evdev)
         libevdev_has_event_code(evdev, EV_ABS, BTN_TOOL_PEN)) /* Don't match wacom tablets */
         return FALSE;
 
+    if (libevdev_has_event_code(evdev, EV_ABS, ABS_MT_SLOT)) {
+        if (libevdev_get_num_slots(evdev) == -1)
+            return FALSE; /* Ignore fake MT devices */
+
+        if (!libevdev_has_event_code(evdev, EV_ABS, ABS_MT_POSITION_X) ||
+            !libevdev_has_event_code(evdev, EV_ABS, ABS_MT_POSITION_Y))
+            return FALSE;
+    }
+
     return TRUE;
 }