From 680301f05337b586ed47d4521ab40b074ab60c79 Mon Sep 17 00:00:00 2001
From: Christopher Rackauckas <accounts@chrisrackauckas.com>
Date: Sat, 25 Nov 2023 22:31:10 -0500
Subject: [PATCH] Add safety zeroing in RadauIIA5 non fully defined Jacobians

More generally fixes https://github.com/SciML/DifferentialEquations.jl/issues/1001
---
 src/caches/firk_caches.jl | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/caches/firk_caches.jl b/src/caches/firk_caches.jl
index 536f5bffde..a0b8b46b08 100644
--- a/src/caches/firk_caches.jl
+++ b/src/caches/firk_caches.jl
@@ -239,6 +239,7 @@ function alg_cache(alg::RadauIIA5, u, rate_prototype, ::Type{uEltypeNoUnits},
         error("Non-concrete Jacobian not yet supported by RadauIIA5.")
     end
     W2 = similar(J, Complex{eltype(W1)})
+    recursivefill!(W2, false)
 
     du1 = zero(rate_prototype)