null values

[Jarosław Pękala <jaroslaw.pekala@…>]

When data contains nulls like: Sp_data Ideal Real 2013-06-22 00:00:00+02:00 39 39 2013-06-22 00:00:00+02:00 39 2013-06-23 00:00:00+02:00 36 2013-06-24 00:00:00+02:00 33 32

error is raised: All series on a given axis must be of the same data type

when null value is replaced by exact value ex: Sp_data Ideal Real 2013-06-22 00:00:00+02:00 39 39 2013-06-22 00:00:00+02:00 1 39 2013-06-23 00:00:00+02:00 36 1 2013-06-24 00:00:00+02:00 33 32 chart is ok

I added to [vis] in trac.ini options = interpolateNulls:true but result is the same as without this line