getBBox() (implemented with objectBoundingBox()) is often wrong
RenderSVGTSpan has an empty implementation. RenderForeignObject returns the borderBox() which, although un-spec'd, is correct according to Doug and Erik in #svg. They may yet issue an Errata to cover the issue.
I'm sure other SVG renderers are missing proper objectBoundingBox() implementations (which will show up as ASSERTs in debug mode when viewing the right SVGs, or when calling getBBox() on the right elements). This bug tracks fixing all these and landing a test case testing getBBox() on various SVG elements.
Fixed in trunk. Closing bug.