[gdal-dev] gdalwarp's default nodata value

[Even Rouault]

Joaquim,

>
> For the rec, VS2010 and a quite recent trunk version.

Ah, this is the reason for the different results we got. On Windows, 
atof("nan") returns 0... but on Linux it returns a nan number.

I've pushed quite a few changes to trunk to improve the situation on Windows 
and other changes for all platforms to fix the case when we compare pixel 
values to nodata value and the nodata value is nan. Indeed, the test "value 
== dfNoDataValue" that was generally used fails if value == nan and 
dfNoDataValue == nan, because nan != nan...

See http://trac.osgeo.org/gdal/ticket/3576

Best regards,

Even