Fix iteraction between ComputeIdealPoint and MOI.empty! (#98)

Author: odow

src/MultiObjectiveAlgorithms.jl

@@ -132,7 +132,6 @@ function MOI.empty!(model::Optimizer)
     model.termination_status = MOI.OPTIMIZE_NOT_CALLED
     model.solve_time = NaN
     empty!(model.ideal_point)
-    model.compute_ideal_point = default(ComputeIdealPoint())
     return
 end
 
@@ -142,8 +141,7 @@ function MOI.is_empty(model::Optimizer)
            isempty(model.solutions) &&
            model.termination_status == MOI.OPTIMIZE_NOT_CALLED &&
            isnan(model.solve_time) &&
-           isempty(model.ideal_point) &&
-           model.compute_ideal_point == default(ComputeIdealPoint())
+           isempty(model.ideal_point)
 end
 
 MOI.supports_incremental_interface(::Optimizer) = true

test/test_model.jl

@@ -176,6 +176,13 @@ end
 function test_ideal_point()
     for (flag, result) in (true => [0.0, -9.0], false => [NaN, NaN])
         model = MOA.Optimizer(HiGHS.Optimizer)
+        @test MOI.supports(model, MOA.ComputeIdealPoint())
+        @test MOI.get(model, MOA.ComputeIdealPoint())
+        @test MOI.set(model, MOA.ComputeIdealPoint(), flag) === nothing
+        @test MOI.get(model, MOA.ComputeIdealPoint()) == flag
+        # Test that MOI.empty! does not override ComputeIdealPoint
+        MOI.empty!(model)
+        @test MOI.get(model, MOA.ComputeIdealPoint()) == flag
         MOI.set(model, MOI.Silent(), true)
         x = MOI.add_variables(model, 2)
         MOI.add_constraint.(model, x, MOI.GreaterThan(0.0))
@@ -187,10 +194,6 @@ function test_ideal_point()
             -1.0 * x[1] - 2.0 * x[2],
         ])
         MOI.set(model, MOI.ObjectiveFunction{typeof(f)}(), f)
-        @test MOI.supports(model, MOA.ComputeIdealPoint())
-        @test MOI.get(model, MOA.ComputeIdealPoint())
-        @test MOI.set(model, MOA.ComputeIdealPoint(), flag) === nothing
-        @test MOI.get(model, MOA.ComputeIdealPoint()) == flag
         MOI.optimize!(model)
         point = MOI.get(model, MOI.ObjectiveBound())
         @test length(point) == 2