cannot reference self when absolute `id` defined

[figadore]

when a $ref is set to something starting with a '#', the schema validates as expected, unless the id property is set to an absolute uri

var ZSchema = require('z-schema');

var data = {
  color: "blue"
};

var schema = {
  "$schema": "http://json-schema.org/draft-04/hyper-schema",
  "id": "color-1.0",
  "strictProperties": true,
  "additionalProperties": false,
  "definitions": {
    "color": {
      "type": "string",
      "enum": [
        "blue",
        "yellow"
      ]
    }
  },
  "type": [
    "object"
  ],
  "required": [
    "color"
  ],
  "properties": {
    "color": {
      "$ref": "#/definitions/color"
    }
  }
};

var validator = new ZSchema({});
var valid = validator.validate(data, schema);
var errors;
console.log("1st run:", valid);
if (!valid) {
  errors = validator.getLastErrors();
  console.log({errors});
}

schema.id = "http://schemas.example.com/color-1.0";

validator = new ZSchema({});
valid = validator.validate(data, schema);
console.log("2nd run:", valid);
if (!valid) {
  errors = validator.getLastErrors();
  console.log({errors});
}

output

1st run: true
2nd run: false
{ errors: 
   [ { code: 'UNRESOLVABLE_REFERENCE',
       params: [Object],
       message: 'Reference could not be resolved: http://schemas.example.com/#/definitions/color',
       path: '#/properties/color',
       schemaId: 'http://schemas.example.com/color-1.0' } ] }

[figadore]

same result when remote reference set

validator = new ZSchema({});
validator.setRemoteReference(schema.id, schema);
valid = validator.validate(data, schema);
console.log("2nd run:", valid);
if (!valid) {
  errors = validator.getLastErrors();
  console.log({errors});
}

[figadore]

I've narrowed it down to the SchemaCompilation mergeReference function, it sets the reference to http://schemas.example.com/#definitions/color instead of http://schemas.example.com/color-1.0#/definitions/color. I can fix it by adding a trailing # (or /) to the id, i.e. http://schemas.example.com/color-1.0#. Is that the expected behavior? I don't understand the purpose of the trailing # (or /) in either the $schema or id fields