NaN values not being parsed in gdal_rasterize options

[dsogari]

The gdal_rasterize app currently does not handle NaN values for the "-init" and "-burn" options, because of the implementation of the ArgIsNumeric function in gdal_rasterize_lib.cpp::47

If we supply such value, ArgIsNumeric gives false and the 'i' is not incremented when reading either the "-init" or "-burn" options, causing the app to fail in the next iteration.

I propose the following modification: where it reads

   return CPLGetValueType(pszArg) != CPL_VALUE_STRING;

it could be written

   return CPLIsNan(CPLAtof(pszArg)) ||
       CPLGetValueType(pszArg) != CPL_VALUE_STRING;

A patch file is attached for convenience. Thanks

[dsogari]

patch file for gdal_rasterize_lib.cpp

[Even Rouault]

trunk r34043, branches/2.1 r34044 (post 2.1.0RC1), branches/2.0 r34045 "gdal_rasterize: accept NaN as a valid value for -init / -burn (derived from patch by dsogari, #6467)"