// Initially we used 'upper_popup->OpenParentId == window->IDStack.back()' to differentiate multiple menu sets from each others
// (e.g. inside menu bar vs loose menu items) based on parent ID.
// This would however prevent the use of e.g. PuhsID() user code submitting menus.
// This would however prevent the use of e.g. PushID() user code submitting menus.
// Previously this worked between popup and a first child menu because the first child menu always had the _ChildWindow flag,
// making hovering on parent popup possible while first child menu was focused - but this was generally a bug with other side effects.
// making hovering on parent popup possible while first child menu was focused - but this was generally a bug with other side effects.
// Instead we don't treat Popup specifically (in order to consistently support menu features in them), maybe the first child menu of a Popup
// doesn't have the _ChildWindow flag, and we rely on this IsRootOfOpenMenuSet() check to allow hovering between root window/popup and first child menu.
// In the end, lack of ID check made it so we could no longer differentiate between separate menu sets. To compensate for that, we at least check parent window nav layer.
// open on hover, but that should be a lesser problem, because if such menus are close in proximity in window content then it won't feel weird and if they are far apart