Bug in the recursive schema implementation

[rlouf]

Let's consider the following recursive JSON Schema:

{
        "$schema": "http://json-schema.org/draft-07/schema#",
        "definitions": {
            "person": {
                "type": "object",
                "properties": {
                    "name": {"type": "string"},
                    "children": {
                        "type": "array",
                        "items": {"$ref": "#/definitions/person"},
                        "default": [],
                    },
                },
            }
        },
        "type": "object",
        "properties": {"person": {"$ref": "#/definitions/person"}},
    }

If we iterate over the tokens of the following (incomplete) possible generation:

 {"name": "Jae laalkdjfa Winfreed Martin Skye laksdjflksdj alkdjflkajds","children": [{ "name": "Jon Alabasterine Paphnose", "children": [{"name": "Aloysious Johtnose-Paphnose III"}]},{"name": "Pupling joainodf wllldfc ahjolds ujmkew Patriciaica Johnas Pumpernickle Invictis plalkasdf mendoza gillford-throuple jaiop ANoaenla"

we bump into a token that is not in the set of next allowed tokens. It might not be due to the recursive property of the schema, but we need to debug this nevertheless.