Solr 9.7.0 returns fields in different order with fl parameter

[Thomas Corthals]

Hi,

Up until Solr 9.6.1, when using the fl parameter the fields were returned
in what seems to be the same order they are stored in. With Solr 9.7.0,
they are returned in a different order.

With the techproducts example on Solr 9.6.1:

{
  "responseHeader":{
    "status":0,
    "QTime":2,
    "params":{
      "q":"price:[70 TO 80]",
      "fl":"id,price"
    }
  },
  "response":{
    "numFound":1,
    "start":0,
    "numFoundExact":true,
    "docs":[{
      "id":"VS1GB400C3",
      "price":74.99
    }]
  }
}

Same query and field list on Solr 9.7.0:

{
  "responseHeader":{
    "status":0,
    "QTime":44,
    "params":{
      "q":"price:[70 TO 80]",
      "fl":"id,price"
    }
  },
  "response":{
    "numFound":1,
    "start":0,
    "numFoundExact":true,
    "docs":[{
      "price":74.99,
      "id":"VS1GB400C3"
    }]
  }
}

Is there a way to keep the returned field order consistent with how it used
to be? I'm looking at dozens of failed integration tests because of this
changed field order. And I can't change the order in the expected outcome
because the tests have to run against multiple Solr versions.

Thomas