[cairo] cairo_stroke_extents/cairo_fill_extents strangeness

[Damon Chaplin]

Hi,

The returned values from cairo_stroke_extents & cairo_fill_extents seem
pretty weird to me. The returned extents are in user space coordinates,
but reflect the extents in device space (i.e. the bounding box aligns
with device space axes). It took me a while to figure this out - I was
expecting the extents to either be completely in user space or
completely in device space.

(I actually need the extents completely in user space, so I temporarily
reset the transformation matrix.)

It may be too late to change the values returned, so better docs are
probably needed.

Damon