Slicing preview incorrect in terms of visible solid layers

[MartinMajewski]

Version

1.31.2 - prusa3d edition

Operating system type + version

macOS Sierra 10.12.2 Beta

Behavior

The solid layer preview is not consistent / correct in terms of the solid layer count.
I have noticed that there is often one layer less than set inside the solid layer settings.

As seen in the screenshot I set the solid layer count to "1", and on the larger surface further down the object there is one solid top layer, but on the narrower top end of the object there is none.

However, looking at the Layers panel the requested layers exist.

[bubnikv]

Fixed by b859018