Very rare crash when using fb_union method.

[sabiland]

Is this project still maintained?

I am using fb_union (and other methods) quite a lot in my app, but for input I use always random generated paths created by me. And very rarely I get nil exception, very probably because splitSubcurvesWithRange returns nil paths.

Here is stack trace.

[xhruso00]

Your crash comes from splitSubcurvesWithRange(_ range: FBRange, left: Bool, middle: Bool, right: Bool) -> (left: FBBezierCurve?, mid: FBBezierCurve?, right: FBBezierCurve?)
which sets _curve2RightBezier to be nil and this is later force unwrapped

PS: You write a pull request with fix (e.g. no one wants to do free labour)