[CSS Regions] Scrollable elements flowed into regions do not scroll in some situations

• Component: CSS
• Status: RESOLVED INVALID

[Radu Stavila]

If an element with overflow:scroll is flowed into a region, scrolling it using the mouse wheel only works if the OS is configured to always show the scrollbar. Otherwise, scrolling with the wheel doesn't work.

[Radu Stavila]

This happens when the mouse is positioned over a part of the scrollable element which is behind another region, in which the element does NOT flow. Not responding to the wheel event in this situation is normal behavior and happens in the same way when not using regions if the elements are self-painting layers (as regions are).