After upgrade Hibernate ORM from 5.0.2 to 5.0.3 I can't make to work JPQL query which uses Enum value with AttributeConverter as part of WHERE clause.

Given this classes:

package point.data.jpa.entities;

public class DeskTransaction {

  public enum Type {
    TYPE1(1), TYPE2(2);
    private int code;
    private static Map<Integer, Type> typesByCode = new HashMap<>();
    static {
      for (Type type : Type.values()) {
        typesByCode.put(type.code, type);
      }
    }
    public Type(int code) {
      this.code = code;
    }
    public int code getCode() {
      return this.code;
    }
    public static Type fromCode(int code) {
      return typesByCode.get(code);
    }
  }

  @Converter(autoApply = true)
  public static class TypeConverter implements AttributeConverter<Type, Integer> {
    @Override
    public Integer convertToDatabaseColumn(Type attribute) {
      return attribute == null ? null : attribute.getCode();
    }
    @Override
    public Type convertToEntityAttribute(Integer dbData) {
      return dbData == null ? null : Type.fromCode(dbData);
    }
  }

  @Column(nullable = false)
  private Type type;

  @ManyToOne(optional = true)
  @JoinColumn(name = "worker_id")
  private Employee employee;

  @Column(name = "money", nullable = false)
  private BigDecimal sum;

  // getters and setters

}

Before 5.0.3 (up to 5.0.2 inclusive) this JPQL query works (in 4.x it also worked fine):
SELECT dt.employee, -SUM(dt.sum) FROM point.data.jpa.entities.DeskTransaction dt WHERE dt.type = 1 GROUP BY dt.employee

After upgrading to 5.0.3 it don't work anymore and raises exception at application launch:

Caused by: org.hibernate.QueryException: AttributeConverter domain-model attribute type [point.data.jpa.entities.DeskTransaction$Type] did not match query literal type [java.lang.Integer]

I think that before 5.0.3 AttributeConverters were not applied for this JPQL WHERE clause so literal "1" worked because in DB this is INTEGER field. So I tried to replace literal "1" to Enum in this query.

I tried this:
SELECT dt.employee, -SUM(dt.sum) FROM point.data.jpa.entities.DeskTransaction dt WHERE dt.type = TYPE1 GROUP BY dt.employee
In this case application starts fine but when this query executes it raises the exception:

Column "EMPLOYEE_RESPONSIBILITY" not found; SQL statement:
select desktransa0_.worker_id as col_0_0_, -sum(desktransa0_.money) as col_1_0_, employee1_.id as id1_30_, employee1_.enable_adminka as enable_a2_30_, employee1_.enable_switch as enable_s3_30_, employee1_.enable_vpn as enable_v4_30_, employee1_.active as active5_30_, employee1_.birthday as birthday6_30_, employee1_.firstname as firstnam7_30_, employee1_.lastname as lastname8_30_, employee1_.login as login9_30_, employee1_.password as passwor10_30_, employee1_.patronymic as patrony11_30_, employee1_.position as positio12_30_, employee1_.com_config_notifications as com_con13_30_, employee1_.ip_address as ip_addr14_30_ from buhuchet desktransa0_ inner join workers employee1_ on desktransa0_.worker_id=employee1_.id where desktransa0_.type=EMPLOYEE_RESPONSIBILITY and (desktransa0_.worker_id is not null) group by desktransa0_.worker_id [42122-190]

(take no note of additional fields as my real DeskTransaction and Employee classes are little bigger)

The real problem here is desktransa0_.type=EMPLOYEE_RESPONSIBILITY. Of course this is not correct SQL.

Then I tried to wrote full qualified class name for enum:
SELECT dt.employee, -SUM(dt.sum) FROM point.data.jpa.entities.DeskTransaction dt WHERE dt.type = point.data.jpa.entities.DeskTransaction.Type.TYPE1 GROUP BY dt.employee

This causes exception:

Caused by: org.hibernate.hql.internal.ast.QuerySyntaxException: Invalid path: 'point.data.jpa.entities.DeskTransaction.Type.EMPLOYEE_RESPONSIBILITY' [SELECT dt.employee, -SUM(dt.sum) FROM point.data.jpa.entities.DeskTransaction dt WHERE dt.type = point.data.jpa.entities.DeskTransaction.Type.EMPLOYEE_RESPONSIBILITY AND dt.employee IS NOT NULL GROUP BY dt.employee]

Then I changed nested class divider from dot to "$" sign:
SELECT dt.employee, -SUM(dt.sum) FROM point.data.jpa.entities.DeskTransaction dt WHERE dt.type = point.data.jpa.entities.DeskTransaction$Type.TYPE1 GROUP BY dt.employee

And finally it works fine!

I find this last solution while wroting this report and now not sure if it is bug at all. Maybe wroting nested classes in class-loader format with "$" as divider is right solution?

But even if this is true then when this has been changed? I check all changes between 5.0.2 and 5.0.3 and found only

Maybe it should be documented somewhere as many JPQL queries became broken after upgrading to 5.0.3. I think it is bug that type = 1 worked before (skipping AttributeConverters) but it worked quite a while...

And maybe it is possible to make type = TYPE1 (without FQCN) also works? If class of type is known at runtime then we can deduce enum class for TYPE1.