Zarr generation creates a unexpected array value for fill_value

[rouault]

Version: libnetcdf 4.8.0, built on Ubuntu 20.04 with NCZarr support

Given simple.cdl:

netcdf test {
dimensions:
	dim = 1;
variables:
	int test(dim) ;
		test:_FillValue = -32767 ;
data:

 test = 1;
}

~/install-netcdf-4.8.0/bin/ncgen -4 -lb -o "file://simple_zarr#mode=nczarr,file" simple.cdl generates a simple_zarr/test/.zarray file with following content :

"zarr_format": 2,"shape": [1],"dtype": "<i4","chunks": [1],"fill_value": [-32767],"order": "C","compressor": null,"filters": null}

"fill_value": [-32767] doesn't match what the Python Zarr reference implementation does. It would generate "fill_value": -32767 . The spec at https://zarr.readthedocs.io/en/stable/spec/v2.html#fill-value-encoding is admittedly a bit vague about that, but I wouldn't expect an array from reading it.

[DennisHeimbigner]

Good catch. I will have to check, but in netcdf. the value of the attribute is actually a sequence of values, possibly of size 1. I did the translation directly. Instead, I should see if the attribute has a single value and then stored it as such.
Should be an easy fix.

[DennisHeimbigner]

Also, this applies because of the netcdf _FillValue attribute.

[DennisHeimbigner]

Fixed by PR #2017