Multibyte characters on chunk boundaries get corrupted.

lib/core/dispatchRequest.js
'use strict';
var utils = require('./../utils');
var transformData = require('./transformData');
var isCancel = require('../cancel/isCancel');
var defaults = require('../defaults');
/**
 * Throws a `Cancel` if cancellation has been requested.
 */
function throwIfCancellationRequested(config) {
  if (config.cancelToken) {
    config.cancelToken.throwIfRequested();
  }
}