wrong judgement by is_inside()

[fromprimary]

When I randomly generate room and source position with pyroomacoustic and make sure the source position is in the room by myself, I found that add_source also judges if the source is in the room by function is_inside(). But the function is_inside() sometimes get wrong judgement.
For example, I created a room from conner, the corners are [0,0],[0,7],[8,7],[8,0], the height of the room is 5 . And the source position is [1.94870083,4.86891461,0.84502311], the point outside the room is [0.36537378, 2.36251983,-8.6128589] . This group of data could make the function give wrong result.
This situation is not very frequntly happened, sometimes twice a day.