[netcdfgroup] Netcdf error in nc_close when a string array is defined

• To: "netcdfgroup@xxxxxxxxxxxxxxxx" <netcdfgroup@xxxxxxxxxxxxxxxx>
• Subject: [netcdfgroup] Netcdf error in nc_close when a string array is defined
• From: Blaise, Sébastien <s.blaise@xxxxxxxxx>
• Date: Mon, 20 Aug 2018 14:28:30 +0000

Hi all,

I encountered something that looks like a bug in netcdf, but as a new user of 
the lib I may be wrong somewhere. I have a simple code that creates a netcdf 
file, defines a dimension and a string variable, closes the file, then try to 
reopen it and close it again.
#include <netcdf.h>
#include <iostream>

static void checkNetcdf(int status){
    if (status != NC_NOERR){
        printf("NETCDF error: %s\n", nc_strerror(status));
        std::exit(-1);
    }
}

int main() {
    int rootGrp;
    checkNetcdf(nc_create("test.nc", NC_NETCDF4, &rootGrp));
    int fieldDimId;
    checkNetcdf(nc_def_dim(rootGrp, "field", 5, &fieldDimId));
    int fieldVarId, fieldVarDims[1];
    fieldVarDims[0] = fieldDimId;
    checkNetcdf(nc_def_var(rootGrp, "field", NC_STRING, 1, fieldVarDims, 
&fieldVarId));
    checkNetcdf(nc_close(rootGrp));
    checkNetcdf(nc_open("test.nc", NC_WRITE, &rootGrp));
    checkNetcdf(nc_close(rootGrp));

}
However, it crashes at runtime.
I installed the NetCDF-4 64-bit pre-built library on Windows. When I debug in 
visual studio, x64 I get:
testNetcdfString.exe has triggered a breakpoint.
The program is stopped at the second (last) nc_close.
In normal execution, I have the classical Windows popup: testNetcdfString.exe 
has stopped working
Is there anything wrong in this code or is it a bug? This only happens when 
using NC_STRING type, not with other types.

Kind regards,

Sebastien Blaise
Senior Engineer

T +32 (0)2 77 60 624
s.blaise@xxxxxxxxx | www.fugro.be
Fugro
Av. de Broqueville 12, 1150 Brussels, Belgium
VAT nr BE0418609636