Using additionalProperties and oneOf together results in unexpected behavior

[bhch]

When an object has additionalProperties and oneOf present, the form ui interprets the oneOf fields as the parent object's additional property.

Schema:

{
  "type": "object",
  "properties": {
    "name": {"type": "string"}
  },
  "additionalProperties": true,
  "oneOf": [
    {
      "properties": {
        "age": {"type": "string"}
      },
      "additionalProperties": true
    }
  ]
}