Regression: Swagger CodeGen generates duplicate fields in child DTOs about swagger-codegen

[andrewfg]

The issue occurs when a YAML DTO extends another DTO as follows where TadoModeTerminationCondition implements allOf the fields of OverlayTerminationCondition. CodeGen v2.3.1 generates Java code in which the child DTO does NOT include the same fields as the parent DTO (since they are already inherently in the parent). By contrast CodeGen v2.4.41 generates code where the child DTO has fields that DUPLICATE the same fields in the parent. Which is what causes the GSON JSON deserializer to fall over..

================ YAML Definition ================

OverlayTerminationCondition:
    type: object
    discriminator: type
    properties:
      type:
        $ref: "#/definitions/OverlayTerminationConditionType"
      projectedExpiry:
        description: |
          [ISO8601 datetime](https://en.wikipedia.org/wiki/ISO_8601). E.g. `2015-09-28T15:03:20Z` with second precision.
          Only relevant when receiving an overlay, ignored when overlay is sent to the server. Indicates the expected time of
          termination for this overlay, if no app user moves. `null` means that the overlay never expires (by itself, unless manully removed).
        type: string
        format: date-time
        readOnly: true
    required:
    - type

TadoModeTerminationCondition:
    description: The overlay terminates when the tado mode changes or when the setting (power, temperature, ...) of the underlying block schedule changes (or when removed manually).
    x-discriminator-value: TADO_MODE
    allOf:
    - $ref: "#/definitions/OverlayTerminationCondition"

================ Output of Swagger CodeGen v2.3.1 ================

public class OverlayTerminationCondition  {
  @SerializedName("type")
  private OverlayTerminationConditionType type = null;

  @SerializedName("projectedExpiry")
  private OffsetDateTime projectedExpiry = null;

  ... methods
}


public class TadoModeTerminationCondition extends OverlayTerminationCondition  {

  .. inherited methods all annotated with @Override
}

================ Output of Swagger CodeGen v2.4.41 ================

public class OverlayTerminationCondition  {
  @SerializedName("type")
  private OverlayTerminationConditionType type = null;

  @SerializedName("projectedExpiry")
  private OffsetDateTime projectedExpiry = null;

  ... methods
}


public class TadoModeTerminationCondition extends OverlayTerminationCondition  {
  @SerializedName("type")
  private OverlayTerminationConditionType type = null;

  @SerializedName("projectedExpiry")
  private OffsetDateTime projectedExpiry = null;

  .. inherited methods all annotated with @Override
}

[andrewfg]

^
From deep Googling one hypothesis is the issue may be related to supportsInheritance. => Does anyone have thought on this? And is so, how would I set a different value of that property for the Swagger Maven plugin in the OpenHAB pom.xml file?