Is the CompositeOverlayWindow supposed to be resized when a new monitor is attached?

[Maarten Maathuis]

I've been getting bugreports about people having issues with certain
composite managers. Like not having anything displayed on their second
screen. A recent report included a hint that it may have something to
do with the composite manager rendering to the Composite Overlay
window instead of the root window.

Looking at the code, it seems that this overlay is allocated once and
never changed again. This doesn't seem like the appropriate
beheaviour, unless i'm misunderstanding the code.

These issues occur for a randr-1.2 driver in case that's of any interest.

Maarten.