[cairo] Questions about clipping

[Enzo Ferrari]

Hello,
I am a software developer trying to use the Cairo version 1.2.6 in my 
application.
There's question I'd like to ask about clipping: I know that visible 
region has (0,0)-(1,1) range, but we need in some case to draw an object 
which contour is ALL outside the visible region.
For example: we'd like to draw a filled circle having radius greater 
than 0.5, centered in (0.5,0.5), resulting in a circle that is 
completely outside visible area.
If I try to make this, Cairo crashes with an exception.
How can I avoid this error? Are there some ways to correctly clip?

Thanks in advance.

-- 
Enzo Ferrari
Sviluppo Software Didattico
Coop. Anastasis - Bologna
http://www.anastasis.it