This case does not appear to be correct for the straight skeleton

[NeverMore-Father]

I don't think there should be an empty triangle。
The data of the test polygon is
（0，0）
（4，0）
（4，-4）
（8，-4）
（8，-10）
（-4，-10）
（-4，-4）
（0，-4）

[BorisTheBrave]

I think this is a numeric problem with parallel lines - adjusting certain points a small amount in the y axis fixes it, but not sliding them in the x-axis.

As the author is not responding, I'd recommend you randomly jitter your points slightly to avoid this sort of colinearity.

[reinterpretcat]

Sorry, I missed original bug as I'm not actively working on the topic anymore. I would agree with the suggestion