[Inkscape-devel] weird livarot crash

I've been working on some of the groundwork for the layers dialog; doing a routine test build, I discovered that Inkscape had started crashing.

Backtrace points to livarot, which I haven't touched at all...

The only part of my new code that is actually currently used is the addition of three sigc++ signals to SPReprDoc; so far as I can tell that should not cause Shape::~Shape() to crash..

Can you all review this patch (attached) and see if I'm missing something obvious? I'm at my wits' end here...

-mental