From 98beb5f5cd0f6cc0210d575433e47e4b7c92ca35 Mon Sep 17 00:00:00 2001
From: MaxenceGollier <mgollier45@gmail.com>
Date: Mon, 2 Mar 2026 16:38:27 -0500
Subject: [PATCH 1/2] add is_subsolver field for TRDH

---
 src/TRDH_alg.jl | 6 ++++--
 src/TR_alg.jl   | 2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/TRDH_alg.jl b/src/TRDH_alg.jl
index 6a76ce0c..4da3fe93 100644
--- a/src/TRDH_alg.jl
+++ b/src/TRDH_alg.jl
@@ -24,12 +24,14 @@ mutable struct TRDHSolver{
   u_bound::V
   l_bound_m_x::V
   u_bound_m_x::V
+  is_subsolver::Bool
 end
 
 function TRDHSolver(
   reg_nlp::AbstractRegularizedNLPModel{T, V};
   D::Union{Nothing, AbstractDiagonalQuasiNewtonOperator} = nothing,
   χ = NormLinf(one(T)),
+  is_subsolver = false,
 ) where {T, V}
   x0 = reg_nlp.model.meta.x0
   l_bound = reg_nlp.model.meta.lvar
@@ -46,7 +48,6 @@ function TRDHSolver(
   dk = similar(x0)
   has_bnds = any(l_bound .!= T(-Inf)) || any(u_bound .!= T(Inf))
 
-  is_subsolver = reg_nlp.h isa ShiftedProximableFunction # case TRDH is used as a subsolver
   if is_subsolver
     ψ = shifted(reg_nlp.h, xk)
     @assert !has_bnds
@@ -87,6 +88,7 @@ function TRDHSolver(
     u_bound,
     l_bound_k,
     u_bound_k,
+    is_subsolver,
   )
 end
 
@@ -275,7 +277,7 @@ function SolverCore.solve!(
   χ = solver.χ
   has_bnds = solver.has_bnds
 
-  is_subsolver = h isa ShiftedProximableFunction # case TRDH is used as a subsolver
+  is_subsolver = solver.is_subsolver
 
   if has_bnds
     l_bound_m_x, u_bound_m_x = solver.l_bound_m_x, solver.u_bound_m_x
diff --git a/src/TR_alg.jl b/src/TR_alg.jl
index 7d3d9bbe..157420e2 100644
--- a/src/TR_alg.jl
+++ b/src/TR_alg.jl
@@ -71,7 +71,7 @@ function TRSolver(
   sub_nlp = R2NModel(Bk, ∇fk, zero(T), x0) #FIXME 
   subpb = RegularizedNLPModel(sub_nlp, ψ)
   substats = RegularizedExecutionStats(subpb)
-  subsolver = subsolver(subpb)
+  subsolver = subsolver == TRDHSolver ? subsolver(subpb, is_subsolver = true) : subsolver(subpb)
 
   return TRSolver(
     xk,

From 66a69130ba7c28070d3d974d181ff5e969850400 Mon Sep 17 00:00:00 2001
From: MaxenceGollier <mgollier45@gmail.com>
Date: Mon, 2 Mar 2026 16:54:32 -0500
Subject: [PATCH 2/2] add is_subsolver field for trdh constructor

---
 src/LMTR_alg.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/LMTR_alg.jl b/src/LMTR_alg.jl
index 26187432..8412377f 100644
--- a/src/LMTR_alg.jl
+++ b/src/LMTR_alg.jl
@@ -70,7 +70,7 @@ function LMTRSolver(
   sub_nlp = LMModel(Jk, Fk, T(0), xk)
   subpb = RegularizedNLPModel(sub_nlp, ψ)
   substats = RegularizedExecutionStats(subpb)
-  subsolver = subsolver(subpb)
+  subsolver = subsolver == TRDHSolver ? subsolver(subpb, is_subsolver = true) : subsolver(subpb)
 
   return LMTRSolver{T, typeof(ψ), V, typeof(χ), typeof(subsolver), typeof(subpb)}(
     xk,