Comment 5 for bug 1429107

Adding the Color Matrix filter primitive via GUI creates this filter definition (same in 0.48 as in latest trunk):

      <feColorMatrix
         id="feColorMatrix4197" />

Editing the matrix afterwards (via GUI) results in:

      <feColorMatrix
         id="feColorMatrix4197"
         values="1 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 1 0 " />

Both Chromium and Batik 1.7 (Squiggle) render both effects with visible output, whereas the new cairo renderer apparently does not produce output unless the feColorMatrix node has a 'values' attribute.

<quote src="SVG 1.1 specification">
* type = "matrix | saturate | hueRotate | luminanceToAlpha"
(...). If attribute ‘type’ is not specified, then the effect is as if a value of matrix were specified. (...)

* values = "list of <number>s"
(...). If the attribute is not specified, then the default behavior depends on the value of attribute ‘type’. If type="matrix", then this attribute defaults to the identity matrix. (...)
</quote>
http://www.w3.org/TR/SVG11/filters.html#feColorMatrixElement