From 23f6dfec8e8f4be4fe3fcb30f6ca139ee25902b5 Mon Sep 17 00:00:00 2001
From: jClugstor <jadonclugston@gmail.com>
Date: Tue, 2 Sep 2025 12:47:41 -0400
Subject: [PATCH 1/3] add copy methods for Jacobian Operators

---
 .../src/SciMLJacobianOperators.jl             | 29 +++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/lib/SciMLJacobianOperators/src/SciMLJacobianOperators.jl b/lib/SciMLJacobianOperators/src/SciMLJacobianOperators.jl
index 8a697372c..61957e664 100644
--- a/lib/SciMLJacobianOperators/src/SciMLJacobianOperators.jl
+++ b/lib/SciMLJacobianOperators/src/SciMLJacobianOperators.jl
@@ -404,6 +404,35 @@ function get_dense_ad(ad::AutoSparse)
     return dense_ad
 end
 
+function Base.copy(J::JacobianOperator)
+    return JacobianOperator(
+        J.mode,
+        J.jvp_op,
+        J.vjp_op,
+        copy(J.size),
+        copy(J.input_cache),
+        copy(J.output_cache)
+    )
+end
+
+function Base.copy(J::StatefulJacobianOperator)
+    return StatefulJacobianOperator(
+        copy(J.jac_op),
+        copy(u),
+        copy(p)
+    )
+end
+
+function Base.copy(J::StatefulJacobianNormalFormOperator)
+    return StatefulJacobianNormalFormOperator(
+        copy(J.vjp_operator),
+        copy(J.jvp_operator),
+        copy(J.cache)
+    )
+
+end
+
+
 export JacobianOperator, VecJacOperator, JacVecOperator
 export StatefulJacobianOperator
 export StatefulJacobianNormalFormOperator

From c084d5a80175a1f7c1e1216ce85bfc22192dcff3 Mon Sep 17 00:00:00 2001
From: jClugstor <jadonclugston@gmail.com>
Date: Tue, 2 Sep 2025 13:07:14 -0400
Subject: [PATCH 2/3] account for possible nothings

---
 .../src/SciMLJacobianOperators.jl                  | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/lib/SciMLJacobianOperators/src/SciMLJacobianOperators.jl b/lib/SciMLJacobianOperators/src/SciMLJacobianOperators.jl
index 61957e664..9a8b8dc30 100644
--- a/lib/SciMLJacobianOperators/src/SciMLJacobianOperators.jl
+++ b/lib/SciMLJacobianOperators/src/SciMLJacobianOperators.jl
@@ -410,24 +410,24 @@ function Base.copy(J::JacobianOperator)
         J.jvp_op,
         J.vjp_op,
         copy(J.size),
-        copy(J.input_cache),
-        copy(J.output_cache)
+        isnothing(J.input_cache) ? nothing : copy(J.input_cache),
+        isnothing(J.output_cache) ? nohting : copy(J.output_cache)
     )
 end
 
 function Base.copy(J::StatefulJacobianOperator)
     return StatefulJacobianOperator(
         copy(J.jac_op),
-        copy(u),
-        copy(p)
+        isnothing(J.u) ? nothing : copy(J.u),
+        isnothing(J.p) ? nothing : copy(J.p)
     )
 end
 
 function Base.copy(J::StatefulJacobianNormalFormOperator)
     return StatefulJacobianNormalFormOperator(
-        copy(J.vjp_operator),
-        copy(J.jvp_operator),
-        copy(J.cache)
+        isnothing(J.vjp_operator) ? nothing : copy(J.vjp_operator),
+        isnothing(J.jvp_operator) ? nothing : copy(J.jvp_operator),
+        isnothing(J.cache) ? nothing : copy(J.cache)
     )
 
 end

From fd6d93e5cbbd55dc5a3a60a6936003c6482518f8 Mon Sep 17 00:00:00 2001
From: Christopher Rackauckas <accounts@chrisrackauckas.com>
Date: Tue, 2 Sep 2025 13:10:18 -0400
Subject: [PATCH 3/3] Update
 lib/SciMLJacobianOperators/src/SciMLJacobianOperators.jl

---
 .../src/SciMLJacobianOperators.jl                  | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/lib/SciMLJacobianOperators/src/SciMLJacobianOperators.jl b/lib/SciMLJacobianOperators/src/SciMLJacobianOperators.jl
index 9a8b8dc30..833ce59e8 100644
--- a/lib/SciMLJacobianOperators/src/SciMLJacobianOperators.jl
+++ b/lib/SciMLJacobianOperators/src/SciMLJacobianOperators.jl
@@ -410,24 +410,24 @@ function Base.copy(J::JacobianOperator)
         J.jvp_op,
         J.vjp_op,
         copy(J.size),
-        isnothing(J.input_cache) ? nothing : copy(J.input_cache),
-        isnothing(J.output_cache) ? nohting : copy(J.output_cache)
+        J.input_cache === nothing ? nothing : copy(J.input_cache),
+        J.output_cache === nothing ? nohting : copy(J.output_cache)
     )
 end
 
 function Base.copy(J::StatefulJacobianOperator)
     return StatefulJacobianOperator(
         copy(J.jac_op),
-        isnothing(J.u) ? nothing : copy(J.u),
-        isnothing(J.p) ? nothing : copy(J.p)
+        J.u === nothing ? nothing : copy(J.u),
+        J.p === nothing ? nothing : copy(J.p)
     )
 end
 
 function Base.copy(J::StatefulJacobianNormalFormOperator)
     return StatefulJacobianNormalFormOperator(
-        isnothing(J.vjp_operator) ? nothing : copy(J.vjp_operator),
-        isnothing(J.jvp_operator) ? nothing : copy(J.jvp_operator),
-        isnothing(J.cache) ? nothing : copy(J.cache)
+        J.vjp_operator === nothing ? nothing : copy(J.vjp_operator),
+        J.jvp_operator === nothing ? nothing : copy(J.jvp_operator),
+        J.cache === nothing ? nothing : copy(J.cache)
     )
 
 end