add test, fix tolerance

test/solvers/test_convex_bundle_method.jl

@@ -166,7 +166,7 @@ using Manopt: sectional_curvature, ζ_1, ζ_2, close_point
         )
         q = get_solver_result(cbm_s)
         m = median(M, data)
-        @test distance(M, q, m) < 1e-2 #with default params this is not very precise
+        @test distance(M, q, m) < 1.5e-2 #with default params this is not very precise
         # tst the other stopping criterion mode
         q2 = convex_bundle_method(
             M,

test/solvers/test_quasi_Newton.jl

@@ -1,6 +1,18 @@
 using Manopt, Manifolds, Test
 using LinearAlgebra: I, eigvecs, tr, Diagonal
 
+struct QuasiNewtonGradientDirectionUpdate{VT<:AbstractVectorTransportMethod} <:
+       AbstractQuasiNewtonDirectionUpdate
+    vector_transport_method::VT
+end
+function (d::QuasiNewtonGradientDirectionUpdate)(mp, st)
+    return get_gradient(st)
+end
+function (d::QuasiNewtonGradientDirectionUpdate)(r, mp, st)
+    r .= get_gradient(st)
+    return r
+end
+
 @testset "Riemannian quasi-Newton Methods" begin
     @testset "Show & Status" begin
         M = Euclidean(4)
@@ -357,6 +369,22 @@ using LinearAlgebra: I, eigvecs, tr, Diagonal
         @test contains(qns.direction_update.message, "gradient")
     end
 
+    @testset "Broken direction update" begin
+        M = Euclidean(2)
+        p = [0.0, 1.0]
+        f(M, p) = sum(p .^ 2)
+        grad_f(M, p) = 2 * sum(p)
+        gmp = ManifoldGradientObjective(f, grad_f)
+        mp = DefaultManoptProblem(M, gmp)
+        qns = QuasiNewtonState(
+            M, p; direction_update=QuasiNewtonGradientDirectionUpdate(ParallelTransport())
+        )
+        @test_logs (
+            :warn,
+            "Computed direction is not a descent direction; resetting to negative gradient",
+        ) match_mode = :any solve!(mp, qns)
+    end
+
     @testset "A Circle example" begin
         M = Circle()
         data = [-π / 2, π / 4, 0.0, π / 4]