Fix invalidating inner when AutomaticDifferentiationBackend is set (#458

)
jump-dev · Feb 12, 2025 · f514ff1 · f514ff1
1 parent 1412187
commit f514ff1
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Showing 2 changed files with 8 additions and 1 deletion.
diff --git a/src/MOI_wrapper.jl b/src/MOI_wrapper.jl
@@ -934,6 +934,10 @@ function MOI.set(
     ::MOI.AutomaticDifferentiationBackend,
     backend::MOI.Nonlinear.AbstractAutomaticDifferentiation,
 )
+    # Setting the backend will invalidate the model if it is different. But we
+    # don't requrire == for `::MOI.Nonlinear.AutomaticDifferentiationBackend` so
+    # act defensive and invalidate regardless.
+    model.inner = nothing
     model.ad_backend = backend
     return
 end

diff --git a/test/MOI_wrapper.jl b/test/MOI_wrapper.jl
@@ -631,12 +631,15 @@ end
 function test_ad_backend()
     model = Ipopt.Optimizer()
     MOI.set(model, MOI.Silent(), true)
+    x = MOI.add_variable(model)
     attr = MOI.AutomaticDifferentiationBackend()
     @test MOI.supports(model, attr)
     @test MOI.get(model, attr) == MOI.Nonlinear.SparseReverseMode()
+    MOI.optimize!(model)
+    @test model.inner isa Ipopt.IpoptProblem
     MOI.set(model, attr, MOI.Nonlinear.ExprGraphOnly())
     @test MOI.get(model, attr) == MOI.Nonlinear.ExprGraphOnly()
-    x = MOI.add_variable(model)
+    @test model.inner === nothing
     f = MOI.ScalarNonlinearFunction(:^, Any[x, 4])
     MOI.set(model, MOI.ObjectiveSense(), MOI.MIN_SENSE)
     MOI.set(model, MOI.ObjectiveFunction{typeof(f)}(), f)