Merge pull request #1111 from SciML/ChrisRackauckas-patch-2

Fix SplitODEProblem fallback for non-DiffCache

Author: ChrisRackauckas

src/problems/ode_problems.jl

@@ -474,7 +474,7 @@ end
 function SplitODEProblem{iip}(f::SplitFunction, u0, tspan, p = NullParameters();
         kwargs...) where {iip}
     if f._func_cache === nothing && iip
-        _func_cache = DiffCache(u0)
+        _func_cache = typeof(u0) <: AbstractArray{<:Number} ? DiffCache(u0) : u0
         f = remake(f; _func_cache)
     end
     ODEProblem(f, u0, tspan, p, SplitODEProblem{iip}(); kwargs...)