Glenn Watson
e5ff8b79a5
In a chain like filter: url(#f) drop-shadow(...), WebRender's SVG filter graph builder clamped the last primitive's subregion to the filter region. That region comes from the SVG filter element, so it only bounds the primitives that element contributed; a CSS filter function after it has its own extent. The shadow was cut off at the edge of the referenced filter's region. Only clamp when the chain ends in a url() filter, which is the case the clamp was written for: SVGFilterInstance computes integer subregions, and the filter region it has to be trimmed to is not integer. Differential Revision: https://phabricator.services.mozilla.com/D324167