tree: damage screen when parent is focused

src/ifs/wl_seat.rs

@@ -584,6 +584,7 @@ impl WlSeatGlobal {
             if let Some(parent) = tl.tl_data().parent.get() {
                 if let Some(tl) = parent.node_toplevel() {
                     self.focus_node(tl.tl_into_node());
+                    self.state.damage();
                 }
             }
         }