Frustrum selection selects polylines incorrectly

Problem:

I have been trying the cell-through (frustrum) selection lately and found out it behave strangely for polylines. It will select a polyline even if none of it's segments intersect with the frustrum.

The behaviour seems to be that polyline gets selected if the frustrum is inside convex area defined by any 3 or more points (can be just subsegment). Here is video of simple polyline, I later tried with one in shape of W and it behaved same on every V segment. frustrum2.mkv

I suspect some issue with processing individual segments for selection, but haven't had time to debug this myself to root-cause.

Expected behavior:

I don't think the polyline should be selected unless it really intersects the frustrum.