Make empty_localpart use constructor instead of convert

Author: andreasnoack

src/darray.jl

@@ -56,7 +56,7 @@ type DArray{T,N,A} <: AbstractArray{T,N}
 end
 
 eltype{T}(::Type{DArray{T}}) = T
-empty_localpart(T,N,A) = convert(A, Array{T}(ntuple(zero, N)))
+empty_localpart(T,N,A) = A(Array{T}(ntuple(zero, N)))
 
 const SubDArray{T,N,D<:DArray} = SubArray{T,N,D}
 const SubOrDArray{T,N} = Union{DArray{T,N}, SubDArray{T,N}}

test/darray.jl

@@ -45,6 +45,11 @@ using SpecialFunctions
         global A134 = drandn(1)
         @test DArray(I -> DistributedArrays.localpart(A134), A134) == A134
     end
+
+    @testset "empty_localpart should work when only constructor (not conversion is defined)" begin
+        @test DistributedArrays.empty_localpart(Float64,2,LowerTriangular{Float64,Matrix{Float64}}) isa
+                LowerTriangular
+    end
 end
 
 check_leaks()