Filtering on null throws exception about nhibernate.odata

[justintoth]

CriterionVisitor.cs - ComparisonExpression method can be changed to the following to fix:

public override ICriterion ComparisonExpression(ComparisonExpression expression)
{
var left = ProjectionVisitor.CreateProjection(expression.Left);

        if (expression.Right.ToString() == "null")
            return expression.Operator == Operator.Eq ? Restrictions.IsNull(left) : Restrictions.IsNotNull(left);

        var right = ProjectionVisitor.CreateProjection(expression.Right);

        switch (expression.Operator)
        {
            case Operator.Eq: return Restrictions.EqProperty(left, right);
            case Operator.Ne: return Restrictions.NotEqProperty(left, right);
            case Operator.Gt: return Restrictions.GtProperty(left, right);
            case Operator.Ge: return Restrictions.GeProperty(left, right);
            case Operator.Lt: return Restrictions.LtProperty(left, right);
            case Operator.Le: return Restrictions.LeProperty(left, right);
            default: throw new NotSupportedException();
        }
    }

[pvginkel]

Thank you for reporting this issue. It has been solved with release 0.2.2.0.