Comment 6 for bug 986394

Now I get this exception when loading the test svg:

** (inkscape.exe:6520): WARNING **: Exception during LPE [Unstable!] Power stroke execution. lib2geom exception: Invariants violation (src/2geom/piecewise.h:144)

It is thrown somewhere in the reverse method of this line:
Piecewise<D2<SBasis> > mirrorpath = reverse(compose(pwd2_in,x) - y*compose(n,x));