ImVec2popup_pos=mouse_pos;// NB: In the Navigation branch popup_pos may not use mouse_pos.
ImGuiPopupRefpopup_ref=ImGuiPopupRef(id,parent_window,parent_window->GetID("##Menus"),popup_pos,mouse_pos);// Tagged as new ref because constructor sets Window to NULL.
ImGuiPopupRefpopup_ref;// Tagged as new ref as Window will be set back to NULL if we write this into OpenPopupStack.