Latest Wip crash: Extrusion crv "on limit" opzion

They tell me that Rhino wip crashes if you try to extrude a curve (for example, a pentagon) on a “limit” (for example, a horizontal surface). this also applies to tapered extrusion with “on limit” option.

You try to reproduce the bug.

Also in Rhino 6, extrusion of curves and surface tapered “on the limit” works badly.