[cairo] Surface size before the fact - redux

[donn]

Hi,
I asked recently about the catch-22: when you need to make a surface to 
draw something, but don't know how big to make it — and you need to draw 
it first before you can get the size.

There's a solution using rsvg, but I was wondering how one would do this 
from a normal pycairo pov?
(Say I have some SVG that I have parsed into 'draw' commands - like 
ctx.move_to() etc.- but there was no hint of width/height.)

I should go look through the librsvg source, but I don't feel up to it 
right now. Just fishing the lazyweb. :)

\d