WindowServer: Send WindowDeactivated event to windows blocked by modal

When a new modal window is created, we still want to forward the
WindowDeactivated event to its parent window, despite it being blocked
by the newly created modal (which causes WindowServer's Window::event()
to ignore all incoming events from WindowManager for that window).

This fixes the "terminal doesn't stop blinking when blocked by modal
window" bug.

Services/WindowServer/Window.cpp

@@ -330,8 +330,12 @@ void Window::event(Core::Event& event)
  return;
  }
 
- if (is_blocked_by_modal_window())
- return;
+ if (is_blocked_by_modal_window()) {
+ // We still want to handle the WindowDeactivated event below when a new modal is
+ // created to notify its parent window, despite it being "blocked by modal window".
+ if (event.type() != Event::WindowDeactivated)
+ return;
+ }
 
  if (static_cast<Event&>(event).is_mouse_event())
  return handle_mouse_event(static_cast<const MouseEvent&>(event));