parameter with type=array style=form and explode=true marked as invalid

[Florian Best]

https://swagger.io/docs/specification/serialization/#query and https://swagger.io/docs/specification/describing-parameters/#query-parameters say that query parameters may be type=array with style=form and explode=true.
However, trying to validate such a parameter gives me a invalid result:

$ python3 -m openapi_spec_validator openapi2.json
{'description': 'description', 'in': 'query', 'name': 'properties', 'schema': {'minItems': 1, 'maxItems': 5, 'explode': True, 'style': 'form', 'items': {'example': '*', 'type': 'string', 'minLength': 1, 'maxLength': 5, 'pattern': '.*'}, 'type': 'array'}} is not valid under any of the given schemas

Failed validating 'oneOf' in schema['properties']['paths']['patternProperties']['^\\/']['patternProperties']['^(get|put|post|delete|options|head|patch|trace)$']['properties']['parameters']['items']:                                        
    {'oneOf': [{'$ref': '#/definitions/Parameter'},
               {'$ref': '#/definitions/Reference'}]}

On instance['paths']['/foo']['get']['parameters'][0]:
    {'$ref': '#/components/parameters/search.properties',
     'x-scope': ['file:///…/openapi2.json']}

{
    "components": {
        "callbacks": {},
        "examples": {},
        "headers": {},
        "links": {},
        "parameters": {
            "search.properties": {
                "description": "description",
                "in": "query",
                "name": "properties",
                "schema": {
                    "minItems": 1,
                    "maxItems": 5,
                    "explode": true,
                    "style": "form",
                    "items": {
                        "example": "*",
                        "type": "string",
                        "minLength": 1,
                        "maxLength": 5,
                        "pattern": ".*"
                    },
                    "type": "array"
                }
            }
        },
        "requestBodies": {},
        "responses": {},
        "schemas": {},
        "securitySchemes": {}
    },
    "info": {
        "description": "description",
        "title": "",
        "version": "1.0.0"
    },
    "openapi": "3.0.3",
    "paths": {
        "/foo": {
            "get": {
                "description": "description",
                "operationId": "foo",
                "parameters": [
                    {
                        "$ref": "#/components/parameters/search.properties"
                    }
                ],
                "responses": {
                    "200": {
                        "content": {
                            "application/json": {
                                "schema": {
                                    "description": "description",
                                    "type": "string"
                                }
                            }
                        },
                        "description": "description"
                    }
                },
                "summary": "summary",
                "tags": [
                    "foo"
                ]
            }
        }
    },
    "security": [
    ],
    "servers": [
        {
            "url": "https://localhost"
        }
    ],
    "tags": [
        {
            "description": "description",
            "name": "foo"
        }
    ]
}

when removing:

                    "explode": true,
                    "style": "form",

it is valid again.

[Florian Best]

ah, nvm.
Moving

                    "explode": true,
                    "style": "form",

upwards to the actual property instead of the schema fixes it.