Empty ESRI datum names in gdal_datum.csv produce morphed values of "D"

[johncz711]

There are a few datums (rows) for which the ESRI_DATUM_NAME entry is empty in gdal_datum.csv. For these values, the datum name remapping in morphToESRI produces null strings which are eventually morphed to "D" (the truncated result of prepending "D_" to nothing).

I was able to resolve this by modifying the InitDatumMappingTable function (within ogr_srs_esri.cpp) to detect this case and supply an ESRI-style name by copying the EPSG name and massaging it to replace invalid chars with underbars. After subsequent morph code prepends "D_" the resulting names can be read by ArcMap. The modified code within InitDatumMappingTable reads as follows:

if( MAX(nEPSGNameField,MAX(nDatumCodeField,nESRINameField))

< nFieldCount

&& nMaxDatumMappings > nMappingCount+1 )

{

papszDatumMapping[nMappingCount*3+0] =

CPLStrdup( papszFields[nDatumCodeField] );

if ( (0 == papszFields[nESRINameField])

('\0' == *(papszFields[nESRINameField])) )

{

/* There are some rows in gdal_datum.csv that have */

/* no entry for ESRI_DATUM_NAME. For them, copy */

/* the EPSG datum name and massage it appropriately. */

/* Without this hack, datum name remapping will produce */

/* empty names that are eventually morphed into "D". */

papszDatumMapping[nMappingCount*3+1] =

CPLStrdup( papszFields[nEPSGNameField] );

OGREPSGDatumNameMassage( &(papszDatumMapping[nMappingCount*3+1]) );

}

else

{

/* Use table value if present */

papszDatumMapping[nMappingCount*3+1] =

CPLStrdup( papszFields[nESRINameField] );

}

papszDatumMapping[nMappingCount*3+2] =

CPLStrdup( papszFields[nEPSGNameField] );

OGREPSGDatumNameMassage( &(papszDatumMapping[nMappingCount*3+2]) );

nMappingCount++;

}

A suitably modified copy of ogr_srs_esri.cpp is in the attached zip.

I have successfully used this suggested fix in a subset of OGR code recently added to my (non-ESRI-based) platform for the sole purpose of creating WKT and writing it as .prj files.

[Even Rouault]

This ticket has been automatically closed because Trac is no longer used for GDAL bug tracking, since the project has migrated to GitHub. If you believe this ticket is still valid, you may file it to ​https://github.com/OSGeo/gdal/issues if it is not already reported there.