Make concatenation of vectors of matrices return dense matrix.

Author: pkofod

base/array.jl

@@ -731,6 +731,8 @@ hcat{T}(A::Union{Matrix{T}, Vector{T}}...) = typed_hcat(T, A...)
 vcat(A::Union{Matrix, Vector}...) = typed_vcat(promote_eltype(A...), A...)
 vcat{T}(A::Union{Matrix{T}, Vector{T}}...) = typed_vcat(T, A...)
 
+hvcat(rows::Tuple{Vararg{Int}}, xs::Vector...) = typed_hvcat(promote_eltype(xs...), rows, xs...)
+hvcat{T}(rows::Tuple{Vararg{Int}}, xs::Vector{T}...) = typed_hvcat(T, rows, xs...)
 
 hvcat(rows::Tuple{Vararg{Int}}, xs::Matrix...) = typed_hvcat(promote_eltype(xs...), rows, xs...)
 hvcat{T}(rows::Tuple{Vararg{Int}}, xs::Matrix{T}...) = typed_hvcat(T, rows, xs...)

test/abstractarray.jl

@@ -612,3 +612,8 @@ A = TSlowNIndexes(rand(2,2))
 @test @inferred(indices(rand(3,2), 1)) == 1:3
 @test @inferred(indices(rand(3,2), 2)) == 1:2
 @test @inferred(indices(rand(3,2), 3)) == 1:1
+
+#17088
+let M = rand(10,10)
+    @test !issparse([[M] [M];])
+end