[Proj] Datum shift for Dutch maps 1850-2000

[Frank Warmerdam]

Jan Hartmann wrote:
> This certainly makes a difference! Adding +nadgrids=@null to the 
> original definition gives a map with a 120m South shift, still too much 
> but nearing a solution.  Isn't this a bug in PROJ? I did not request a 
> datum shift, and neither the from-projection, nor the to-projection had 
> a datum defined, only ellipsoids. I am using Proj 4.6.1.

Jan,

An ellipsoid/geocentric based datum shift should not be done if no towgs84
or nadgrids value is provided with 4.6.0 or later. If you believe there is
a bug please file a detailed ticket showing exactly what you were doing.

Best regards,
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