Some Variables in MFDataset are missing name attribute

[jblarsen]

The example code below fails with an AttributeError that "name" does not exist for the time variable in the MFDataset. In a more realistic dataset I noticed that the "name" attribute was present for the latitude and longitude variables which were not aggregated but not present for the time variable and air temperature.

import netCDF4

f1 = 'test1.nc'
f2 = 'test2.nc'

nc1 = netCDF4.Dataset(f1, 'w', format='NETCDF4_CLASSIC')
nc2 = netCDF4.Dataset(f2, 'w', format='NETCDF4_CLASSIC')

nc1.createDimension('time', None)
t1 = nc1.createVariable('time', "f8", ("time",))
t1[:] = [0]                   
print(t1.name)

nc2.createDimension('time', None)
t2 = nc2.createVariable('time', "f8", ("time",))
t2[:] = [1]                   
print(t2.name)

nc1.close()
nc2.close()

nc = netCDF4.MFDataset([f1, f2])
t = nc.variables['time']          
print(t[:])
print(t._name)
print(t.name)

[jswhit]

easy fix (PR #1154)