Comment 50 for bug 156550

> Overlapping Xinerama geometry has always been legal. That's how
> people do crazy things like overlap the edges of projectors to correct
> for vignetting. Newer versions of RANDR merely exacerbate the
> problem by making overlapping geometry much more common,
> because it tries to clone all screens together if it can.

Well something has changed recently, because now I'm getting mail from
people saying "hey, xscreensaver is suddenly not covering my screen".
These are not people doing crazy stuff with projectors, these are people
with out-of-the-box one-screen setups (or possibly, people with laptops)
who had this crap just suddenly start *happening* to them, because on
their vanilla setup, xinerama is suddenly reporting two screens that overlap.

> But ignoring it and using Xinerama geometry instead is fine too, that's
> not going away.

If "just ignore it and use xinerama geometry" were a solution, then there
would be no problem, because that's exactly what's going on right now.

So I have two questions:

1) What is the reason for the recent change? Why are these people with
vanilla systems suddenly presenting two different xinerama rectangles,
and what is that supposed to mean?

2) When I am presented with two overlapping xinerama rectangles,
what am I expected to do, exactly?

The "just ignore it and use xinerama geometry" approach leads to me
creating two xscreensaver root-windows, which overlap, and running
savers on each of them.

(Currently there is a bug that they both end up using the size of the
second one, but even after I fix that, running two savers on the same
rectangle can't possibly be the right thing to do.)