When linking svg in fo-file like <image xlink:href...> as shown on fop svg examples, text is graphic and no searchable text in the resulting pdf file. It works on full embedded svg and, and partly on embedded with <use xlink:href...>. The pdf file shows complete drawing except to the problem with searchable text. It's independent on selected font.
Not all text in SVG can be rendered as text. Some texts have to be rendered as shapes and that's where you lose the ability to search for that text in the PDF. I'm pretty sure the text painting routines could be improved, so I'll keep the bug open but I don't think this is on any FOP committer's radar at the moment. So don't expect a quick resolution. This is also documented at: http://xmlgraphics.apache.org/fop/0.93/graphics.html#svg You say that in certain situations it works. Please be more specific how exactly we should reproduce the differences since I can't be sure that I'll do the right thing based on your explanations. For example, there is no "<image xlink:href..." in FO as you suggest. This is strictly an SVG operation. If it really works in some situations but not in others we may be able to improve the situation without too much work.
resolved invalid due to lack of information (no FO example input, PDF output, etc)
batch transition resolved+invalid to closed+invalid