[cairo] Problem with alpha-channel (Visual Studio)

[Andreas Lobinger]

Hello colleague,

your code looks OK at the first glance. Painting with alpha always
takes the background i.e. the content of the surface that already has
color into context. So it might be that the black you're seeing is the
background shining through. Can you explain your expectations (i.e.
content of the svg) or attach the actual svg?