Crash closing a menubox with scrollbars

[sentry-io]

Sentry Issue: ASEPRITE-M

Only in beta version with multiple UI windows.

EXCEPTION_ACCESS_VIOLATION_READ: Fatal Error: EXCEPTION_ACCESS_VIOLATION_READ
  File "viewport.cpp", line 39, in ui::Viewport::onResize
    Point scroll = static_cast<View*>(parent())->viewScroll();
  File "widget.cpp", line 714, in ui::Widget::setBounds
    onResize(ev);
  File "rect.h", line 45, in gfx::RectT<T>::{ctor}
    w(rect.w), h(rect.h) {
  File "widget.cpp", line 714, in ui::Widget::setBounds
    onResize(ev);
  File "window.cpp", line 741, in ui::Window::windowSetPosition
    child->setBounds(cpos);
...
(15 additional frame(s) were not displayed)