special case of NaN

Author: Alexander-Barth

src/variable.jl

@@ -150,9 +150,12 @@ function _defVar(ds::AbstractDataset,name::SymbolOrString,data,nctype,vardimname
         end
     end
 
-    # make sure a fill value is set
+    maskingvalue_nan = maskingvalue(ds) isa Number && isnan(maskingvalue(ds))
+
+    # make sure a fill value is set if we deduce from the type of data
+    # that it is needed
     if (Tmaskingvalue <: T) && !haskey(attrib,"_FillValue") &&
-        !haskey(kwargs,:fillvalue)
+        !haskey(kwargs,:fillvalue) && !maskingvalue_nan
         push!(attrib,"_FillValue" => fillvalue(nctype))
     end
 

test/memory_dataset.jl

@@ -133,10 +133,6 @@ function CDM.dim(md::MemoryDataset,name::SymbolOrString)
 end
 
 CDM.varnames(ds::MemoryDataset) = collect(keys(ds.variables))
-
-CDM.variable(ds::MemoryDataset,variablename::SymbolOrString) = ds.variables[String(variablename)]
-
-
 CDM.attribnames(md::Union{MemoryDataset,MemoryVariable}) = keys(md._attrib)
 CDM.attrib(md::Union{MemoryDataset,MemoryVariable},name::SymbolOrString) = md._attrib[String(name)]
 

test/test_scaling.jl

@@ -261,3 +261,11 @@ end
 
 @test nonuniontype(Missing,Union{Float64,Missing}) == Float64
 @test nonuniontype(Missing,Union{Missing,Float64}) == Float64
+
+
+
+fname = tempname()
+data = rand(4,5)
+ds = TDS(fname,"c", maskingvalue = NaN)
+ncv = defVar(ds,"data",data,("lon","lat"))
+@test !haskey(ncv.attrib,"_FillValue")