fix linear solve with views (#707)

Closes #706

We don't want to preserve the stride here because it will be copied onto
a plain `Array`.

Author: araujoms

src/solvers/cholmod.jl

@@ -819,7 +819,7 @@ get_perm(FC::FactorComponent) = get_perm(Factor(FC))
 # Conversion/construction
 
 function Dense{T}(A::StridedVecOrMatInclAdjAndTrans) where T<:VTypes
-    d = allocate_dense(size(A, 1), size(A, 2), A isa StridedVecOrMat ? stride(A, 2) : size(A, 1), T)
+    d = allocate_dense(size(A, 1), size(A, 2), size(A, 1), T)
     D = unsafe_wrap(Array, Ptr{eltype(d)}(unsafe_load(pointer(d)).x), size(A), own = false)
     copyto!(D, A)
     return d

test/cholmod.jl

@@ -794,6 +794,7 @@ end
     A = cholesky(sparse(Diagonal(x.\1)))
     @test A\view(fill(1.,10),1:2:10) ≈ x
     @test A\view(Matrix(1.0I, 5, 5), :, :) ≈ Matrix(Diagonal(x))
+    @test A\view(Matrix(1.0I, 6, 5), 1:5, :) ≈ Matrix(Diagonal(x))
 end
 
 @testset "Test \\ for Factor and SparseVecOrMat" begin