[Bug]: GraphQL - Using Fragment inside Inline Fragment returns only null values

[fmaerkl-sw]

Expected behavior

On a query using an external fragment inside an inline fragment like the following:

(...)
... on SomeType {
  ...MyFragment
}
(...)

fragment MyFragment on SomeType {
  id
  someField
}

the id is returned fine, but other fields such as someField are always null, even though a value would be available in the data.

Actual behavior

All contens of queried fields are returned.

Steps to reproduce

On https://demo.pimcore.com/pimcore-datahub-webservices/explorer/products?apikey=6332aa5e6d3d6c0be31da2a8b3442113
perform the following query:

query Car {
  getCar(id: 103) {
    ... on object_Car {
      ...CarFragment
    }
  }
}

fragment CarFragment on object_Car {
  id
  description
}

Even though the decription field contains a value, only null is returned:

{
  "data": {
    "getCar": {
      "id": "103",
      "description": null
    }
  }
}

Interestingly, all of the following queries work as expected:

query Car {
  getCar(id: 103) {
    ... on object_Car {
      id
      description
    }
  }
}

query Car {
  getCar(id: 103) {
    ...CarFragment
  }
}

fragment CarFragment on object_Car {
  id
  description
}

query Car {
  getCar(id: 103) {
    ... on object_Car {
      ...CarFragment
    }
    description2: description
  }
}

fragment CarFragment on object_Car {
  id
  description
}

[github-actions]

Thanks a lot for reporting the issue. We did not consider the issue as "Pimcore:Priority", "Pimcore:ToDo" or "Pimcore:Backlog", so we're not going to work on that anytime soon. Please create a pull request to fix the issue if this is a bug report. We'll then review it as quickly as possible. If you're interested in contributing a feature, please contact us first here before creating a pull request. We'll then decide whether we'd accept it or not. Thanks for your understanding.