Internalize invalid polyline (0.9.0075)

I have a polyline which is invalid (some zero length segments), and when I internalize it there is no clue that its not valid. Then if I copy the parameter storing the internalized geometry I get Null. I suspect that there are also other geometry types which won't really appear invalid... Can we stick to some general rule here ? I think that there might be just a simple .IsValid check before geometry becomes internalized, with some MessageBox appearing if something goes wrong.