Fix deletion before final_touch

Author: blegat

src/Bridges/Constraint/bridges/IntegerToZeroOneBridge.jl

@@ -103,6 +103,10 @@ function MOI.get(::MOI.ModelLike, ::MOI.ConstraintSet, ::IntegerToZeroOneBridge)
 end
 
 function MOI.delete(model::MOI.ModelLike, bridge::IntegerToZeroOneBridge)
+    if isnothing(bridge.last_bounds)
+        # Final touch not called yet, so we don't need to delete anything.
+        return
+    end
     MOI.delete(model, bridge.ci)
     MOI.delete(model, bridge.y)
     return

test/Bridges/Constraint/test_IntegerToZeroOneBridge.jl

@@ -94,6 +94,18 @@ function test_final_touch_twice()
     return
 end
 
+function test_delete_before_final_touch()
+    inner = MOI.Utilities.Model{Int}()
+    model = MOI.Bridges.Constraint.IntegerToZeroOne{Int}(inner)
+    x, cx = MOI.add_constrained_variable(model, MOI.Integer())
+    MOI.add_constraint(model, x, MOI.Interval(1, 3))
+    MOI.delete(model, x)
+    @test !MOI.is_valid(model, x)
+    @test !MOI.is_valid(model, cx)
+    MOI.Bridges.final_touch(model)
+    return
+end
+
 end  # module
 
 TestConstraintIntegerToZeroOne.runtests()