Missing method definitions for column views

[rasmushenningsson]

When using column views of sparse matrices, sparse_view*dense matrix multiplication works well, but sparse_view*sparse does not.
I suspect this is an oversight and that it would be easy to make it work. Is that right?
Here's an example.

julia> S = sparse(1:4, 1:4, 1:4)
4×4 SparseMatrixCSC{Int64, Int64} with 4 stored entries:
 1  ⋅  ⋅  ⋅
 ⋅  2  ⋅  ⋅
 ⋅  ⋅  3  ⋅
 ⋅  ⋅  ⋅  4

julia> Sv = @view S[:,1:2]
4×2 view(::SparseMatrixCSC{Int64, Int64}, :, 1:2) with eltype Int64:
 1  ⋅
 ⋅  2
 ⋅  ⋅
 ⋅  ⋅

julia> Sv*zeros(2)
4-element Vector{Float64}:
 0.0
 0.0
 0.0
 0.0

julia> Sv*spzeros(2)
ERROR: MethodError: no method matching indtype(::SubArray{Int64, 2, SparseMatrixCSC{Int64, Int64}, Tuple{Base.Slice{Base.OneTo{…}}, UnitRange{Int64}}, false})
The function `indtype` exists, but no method is defined for this combination of argument types.