Correct behaviour of Logarithmic scale

[tomvej]

When using NaturalScaleFormat to format logarithmic scale, it works normally with the horizontal scale, however, vertical scale tends to be shifted (i.e. the lowest value is not at the bottom, but shifted up, as much as 60 pixels -- execute DisplayTest and try zooming in for more info.

As of now, it is unclear, whether this is caused by NaturalScaleFormat, the scale itself or its errorenous generation by DisplayTest.