[Bridges] fix deletion before final_touch (#2974)

Co-authored-by: Oscar Dowson <o.dowson@gmail.com>

Author: blegat

src/Bridges/Constraint/bridges/BinPackingToMILPBridge.jl

@@ -129,6 +129,7 @@ function MOI.get(
 end
 
 function MOI.delete(model::MOI.ModelLike, bridge::BinPackingToMILPBridge)
+    # Delete is okay before `final_touch`
     MOI.delete.(model, bridge.less_than)
     empty!(bridge.less_than)
     MOI.delete.(model, bridge.equal_to)

src/Bridges/Constraint/bridges/CountBelongsToMILPBridge.jl

@@ -133,6 +133,7 @@ function MOI.get(
 end
 
 function MOI.delete(model::MOI.ModelLike, bridge::CountBelongsToMILPBridge)
+    # Delete is okay before `final_touch`
     for ci in bridge.equal_to
         MOI.delete(model, ci)
     end

src/Bridges/Constraint/bridges/CountDistinctToMILPBridge.jl

@@ -172,6 +172,7 @@ function MOI.get(
 end
 
 function MOI.delete(model::MOI.ModelLike, bridge::CountDistinctToMILPBridge)
+    # Delete is okay before `final_touch`
     for ci in bridge.equal_to
         MOI.delete(model, ci)
     end

src/Bridges/Constraint/bridges/CountGreaterThanToMILPBridge.jl

@@ -108,6 +108,7 @@ function MOI.get(
 end
 
 function MOI.delete(model::MOI.ModelLike, bridge::CountGreaterThanToMILPBridge)
+    # Delete is okay before `final_touch`
     MOI.delete.(model, bridge.greater_than)
     empty!(bridge.greater_than)
     MOI.delete.(model, bridge.equal_to)

src/Bridges/Constraint/bridges/IntegerToZeroOneBridge.jl

@@ -103,6 +103,9 @@ function MOI.get(::MOI.ModelLike, ::MOI.ConstraintSet, ::IntegerToZeroOneBridge)
 end
 
 function MOI.delete(model::MOI.ModelLike, bridge::IntegerToZeroOneBridge)
+    if bridge.last_bounds === nothing
+        return  # We're deleting the bridge before final_touch
+    end
     MOI.delete(model, bridge.ci)
     MOI.delete(model, bridge.y)
     return

src/Bridges/Constraint/bridges/ReifiedCountDistinctToMILPBridge.jl

@@ -169,6 +169,7 @@ function MOI.delete(
     model::MOI.ModelLike,
     bridge::ReifiedCountDistinctToMILPBridge,
 )
+    # Delete is okay before `final_touch`
     for ci in bridge.equal_to
         MOI.delete(model, ci)
     end

src/Bridges/Constraint/bridges/SemiToBinaryBridge.jl

@@ -186,6 +186,7 @@ function MOI.get(
 end
 
 function MOI.delete(model::MOI.ModelLike, bridge::SemiToBinaryBridge)
+    # Delete is okay, even though we call `final_touch`
     if bridge.integer_index !== nothing
         MOI.delete(model, bridge.integer_index)
     end

test/Bridges/Constraint/test_BinPackingToMILPBridge.jl

@@ -142,6 +142,19 @@ function test_runtests_error_affine()
     return
 end
 
+function test_delete_before_final_touch()
+    inner = MOI.Utilities.Model{Int}()
+    model = MOI.Bridges.Constraint.BinPackingToMILP{Int}(inner)
+    x = MOI.add_variables(model, 2)
+    f = MOI.Utilities.operate(vcat, Int, 2, 1 * x[1], x[2])
+    c = MOI.add_constraint(model, f, MOI.BinPacking(3, [1, 2, 3]))
+    MOI.delete(model, c)
+    @test MOI.is_valid(model, x[1])
+    @test !MOI.is_valid(model, c)
+    MOI.Bridges.final_touch(model)
+    return
+end
+
 end  # module
 
 TestConstraintBinPacking.runtests()

test/Bridges/Constraint/test_CountBelongsToMILPBridge.jl

@@ -127,6 +127,19 @@ function test_runtests_error_affine()
     return
 end
 
+function test_delete_before_final_touch()
+    inner = MOI.Utilities.Model{Int}()
+    model = MOI.Bridges.Constraint.CountBelongsToMILP{Int}(inner)
+    x = MOI.add_variables(model, 2)
+    f = MOI.Utilities.operate(vcat, Int, 2, 1 * x[1], x[2])
+    c = MOI.add_constraint(model, f, MOI.CountBelongs(3, Set([2, 4])))
+    MOI.delete(model, c)
+    @test MOI.is_valid(model, x[1])
+    @test !MOI.is_valid(model, c)
+    MOI.Bridges.final_touch(model)
+    return
+end
+
 end  # module
 
 TestConstraintCountBelongs.runtests()

test/Bridges/Constraint/test_CountDistinctToMILPBridge.jl

@@ -185,6 +185,19 @@ function test_resolve_with_modified_not_equal_to()
     return
 end
 
+function test_delete_before_final_touch()
+    inner = MOI.Utilities.Model{Int}()
+    model = MOI.Bridges.Constraint.CountDistinctToMILP{Int}(inner)
+    x = MOI.add_variables(model, 2)
+    f = MOI.Utilities.operate(vcat, Int, 2, 1 * x[1], x[2])
+    c = MOI.add_constraint(model, f, MOI.CountDistinct(3))
+    MOI.delete(model, c)
+    @test MOI.is_valid(model, x[1])
+    @test !MOI.is_valid(model, c)
+    MOI.Bridges.final_touch(model)
+    return
+end
+
 end  # module
 
 TestConstraintCountDistinct.runtests()