Some more fixes

Author: ParamThakkar123

lib/OrdinaryDiffEqRosenbrock/src/rosenbrock_caches.jl

@@ -705,7 +705,8 @@ struct Rodas4ConstantCache{TF, UF, Tab, JType, WType, F, AD, rateType} <: Rosenb
     W::WType
     linsolve::F
     autodiff::AD
-    du::Vector{rateType}
+    du::rateType
+    ks::Vector{rateType}
 end
 
 tabtype(::Rodas4) = Rodas4Tableau
@@ -723,10 +724,11 @@ function alg_cache(alg::Union{Rodas4, Rodas42, Rodas4P, Rodas4P2}, u, rate_proto
     linprob = nothing #LinearProblem(W,copy(u); u0=copy(u))
     linsolve = nothing #init(linprob,alg.linsolve,alias_A=true,alias_b=true)
     ks = Vector{typeof(rate_prototype)}(undef, 6)
+    du = zero(rate_prototype)
     Rodas4ConstantCache(tf, uf,
         tabtype(alg)(constvalue(uBottomEltypeNoUnits),
             constvalue(tTypeNoUnits)), J, W, linsolve,
-        alg_autodiff(alg), ks)
+        alg_autodiff(alg), du, ks)
 end
 
 function alg_cache(alg::Union{Rodas4, Rodas42, Rodas4P, Rodas4P2}, u, rate_prototype, ::Type{uEltypeNoUnits},

lib/OrdinaryDiffEqRosenbrock/src/rosenbrock_perform_step.jl

@@ -1208,7 +1208,7 @@ end
 
 @muladd function perform_step!(integrator, cache::Rodas4ConstantCache, repeat_step = false)
     (;t, dt, uprev, u, f, p) = integrator
-    (;tf, uf, du) = cache
+    (;tf, uf, du, ks) = cache
     (;A, C, gamma, c, d, H) = cache.tab
 
     # Precalculations

lib/OrdinaryDiffEqRosenbrock/src/stiff_addsteps.jl

@@ -291,7 +291,7 @@ function _ode_addsteps!(k, t, uprev, u, dt, f, p, cache::Rodas4ConstantCache,
         always_calc_begin = false, allow_calc_end = true,
         force_calc_end = false)
     if length(k) < 2 || always_calc_begin
-        (;tf, uf, du) = cache
+        (;tf, uf, du, ks) = cache
         (;A, C, gamma, c, d, H) = cache.tab
 
         # Precalculations