[Spring] mustache model-properties only accessable if property is not referenced via $ref in specification file

[JohannesProbst]

Description

For e.g. the {{#isReadOnly}} mustache property is not accessible if the property is referenced via $ref in the specification file. Seen in pojo.mustache file for language Spring and it's not the only attribute not accessible (e.g. {{#example}}, {{description}} as well).

Swagger-codegen version

3.0.29

Swagger declaration file content or url

Example with not working reference ($ref) on the property grossAmount of the components -> schemas -> LiabilityInsurance:

...
LiabilityInsurance:
      type: object
      description: data necessary for calculating a vehicle liability insurance premium
      properties:
        grossAmount:
          $ref: '#/components/schemas/GrossAmount'
       variant:
           ...
GrossAmount:
      readOnly: true
      description: Gross total after calculation for the respective subdivision.
      type: number
      format: double
      multipleOf: 0.01
      example: 99.98

working example without $ref:

...
LiabilityInsurance:
      type: object
      description: data necessary for calculating a vehicle liability insurance premium
      properties:
        grossAmount:
            readOnly: true
            description: Bruttosumme nach Berechnung für die jeweilige Teilsparte.
            type: number
            format: double
            multipleOf: 0.01
            example: 99.98
       variant:
           ...

[johnathafelix]

I'm also facing this issue. It looks like a regression as it seems that this was fixed in #8277 and observepoint/swagger-codegen-generators#2