Stack overflow when using recursive references, $ref

[davidvisiedo]

I think this issue is related to #59 and #36.

I get a stack overflow when refs are recursive (example copied from #59).

Related to https://json-schema.org/latest/json-schema-core.html#rfc.section.8.3.1

"A schema MUST NOT be run into an infinite loop against a schema. For example, if two schemas "#alice" and "#bob" both have an "allOf" property that refers to the other, a naive validator might get stuck in an infinite recursive loop trying to validate the instance. Schemas SHOULD NOT make use of infinite recursive nesting like this; the behavior is undefined. "

Example:

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": "object",
  "properties": {
    "parent": {
      "$ref": "#/definitions/objectDef"
    }
  }
},
"definitions": {
  "objectDef": {
    "type": "object",
    "properties": {
      "value1": {
        "type": "string"
      },
      "value2": {
        "type": "string"
      },
      "childObject": {
        "$ref": "#/definitions/objectDef"
      }
    }
  }
}

[davidvisiedo]

Code uploaded, Push Request #181

[stevehu]

@davidvisiedo The implementation makes perfect sense. I have asked other developers to review the code as they know more about this area. Thanks a lot for your help.

[stevehu]

@davidvisiedo I have merged the PR to the master branch. Wait for another PR to be reviewed/tested to have another release. Thanks a lot for your help.