When translating quadric shapes -- specifically, paraboloids -- the bounding
box is both scaled and translated.

The bug is in the function Compute_Quadric_BBox() in file quadrics.c.  I
haven't checked to see if the bug affects any quadric shapes other than
paraboloids.
To see the bug, render the example code first with the +MB5 command-line
option to see how the scene should render, then with the +MB1 option to see
the bug.

Example code:
camera{location 11 look_at 0}
light_source{100, 1}
intersection{
 quadric{<1,1,0>,<0,0,0>,<0,0,-1>,0 translate x*1}
 box{<-4,-4,-10>,<4,4,10> pigment{rgb <1,1,0>}}
 pigment{rgb 1}
}

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