[Bridges] fix deleting variable with constraint bridged from scalar to vector

Author: odow

src/Bridges/bridge_optimizer.jl

@@ -511,14 +511,6 @@ function _delete_variables_in_variables_constraints(
     vis::Vector{MOI.VariableIndex},
 )
     c_map = Constraint.bridges(b)::Constraint.Map
-    # Delete all `MOI.VectorOfVariables` constraints of these variables.
-    # We reverse for the same reason as for `VariableIndex` below.
-    # As the iterators are lazy, when the inner bridge constraint is deleted,
-    # it won't be part of the iteration.
-    for ci in
-        Iterators.reverse(Constraint.vector_of_variables_constraints(c_map))
-        _delete_variables_in_vector_of_variables_constraint(b, vis, ci)
-    end
     # Delete all `MOI.VariableIndex` constraints of these variables.
     for vi in vis
         # If a bridged `VariableIndex` constraints creates a second one,
@@ -532,6 +524,15 @@ function _delete_variables_in_variables_constraints(
             end
         end
     end
+    # Delete all `MOI.VectorOfVariables` constraints of these variables.
+    # We reverse for the same reason as for `VariableIndex` below.
+    # As the iterators are lazy, when the inner bridge constraint is deleted,
+    # it won't be part of the iteration.
+    for ci in
+        Iterators.reverse(Constraint.vector_of_variables_constraints(c_map))
+        _delete_variables_in_vector_of_variables_constraint(b, vis, ci)
+    end
+    return
 end
 
 function _delete_variables_in_bridged_objective(

test/Bridges/bridge_optimizer.jl

@@ -1463,6 +1463,35 @@ function test_BridgeRequiresFiniteDomainError()
     return
 end
 
+MOI.Utilities.@model(
+    Model2817,
+    (),
+    (),
+    (MOI.Nonnegatives,),
+    (),
+    (),
+    (),
+    (),
+    (MOI.VectorAffineFunction,)
+);
+
+function MOI.supports_constraint(
+    ::Model2817,
+    ::Type{MOI.VariableIndex},
+    ::Type{S},
+) where {S<:MOI.AbstractScalarSet}
+    return false
+end
+
+function test_issue_2817()
+    model = MOI.Bridges.full_bridge_optimizer(Model2817{Float64}(), Float64);
+    x, _ = MOI.add_constrained_variable(model, MOI.Interval(0.0, 1.0));
+    MOI.delete(model, x)
+    @test !MOI.is_valid(model, x)
+    @test MOI.is_empty(model)
+    return
+end
+
 end  # module
 
 TestBridgeOptimizer.runtests()