fixup calc_W!

Author: oscardssmith

lib/OrdinaryDiffEqDifferentiation/src/derivative_utils.jl

@@ -704,12 +704,19 @@ function calc_W!(W, integrator, nlsolver::Union{Nothing, AbstractNLSolver}, cach
         else
             update_coefficients!(W, uprev, p, t; transform = W_transform, dtgamma)
         end
-        if W.J !== nothing && !(W.J isa AbstractSciMLOperator)
+        if W.J !== nothing && (W.J isa MatrixOperator || !(W.J isa AbstractSciMLOperator))
             islin, isode = islinearfunction(integrator)
-            islin ? (J = isode ? f.f : f.f1.f) :
-            (new_jac && (calc_J!(W.J, integrator, lcache, next_step)))
-            new_W && !isdae &&
+            if islin
+                J = isode ? f.f : f.f1.f
+            elseif new_jac
+                calc_J!(W.J, integrator, lcache, next_step)
+            end
+            if W.J isa MatrixOperator
+                J = J.A
+            end
+            if new_W && !isdae
                 jacobian2W!(W._concrete_form, mass_matrix, dtgamma, J, W_transform)
+            end
         end
     elseif W isa AbstractSciMLOperator && !(W isa StaticWOperator)
         update_coefficients!(W, uprev, p, t; transform = W_transform, dtgamma)

test/interface/linear_solver_split_ode_test.jl

@@ -2,8 +2,6 @@ using Test
 using OrdinaryDiffEq
 using LinearAlgebra, LinearSolve
 
-import OrdinaryDiffEqCore.dolinsolve
-
 n = 8
 dt = 1 / 1000
 u0 = ones(n)