[cairo] svg_cairo_get_size problem

[mental at rydia.net]

Quoting Jason Dorje Short <jdorje at users.sf.net>:

> Maybe looking in the inkscape/sodipodi or librsvg code you could
> find out how they determine the 90 DPI value.

It's just an arbitrary number.

We're very painfully aware of the issue with SVGs being broken in
this fashion; since the Sodipodi fork we've been trying to remove
all uses of non-px absolute units from the SVGs Inkscape generates.

Setting librsvg/librsvg-cairo's DPI to 90 I guess works around the
issue, but only for broken authoring tools (or authors) that
happened to use non-px absolute units, assuming 90 dpi and not
something else.

-mental