Non-standard NamedNodeMap behaviour

[autarc]

The following issue occurs in the phantomjs version 2.1.1 (binary) on Ubuntu and macOS.

In contrast to the default engine behavior of Blink, Gecko & Co. the NamedNodeMap descriptor returns its length property as a key. You can see the problem in this example:

var page = require('webpage').create();

page.onConsoleMessage = console.log.bind(console);

page.open('http://phantomjs.org/', function (status)  {
  page.evaluate(function(){
    var attributesKeys = Object.keys(document.body.attributes);
    console.log(JSON.stringify(attributesKeys)); // NamedNodeMap properties -> ['length']
  });
  phantom.exit();
});

The expected behavior would be the return of [] (an empty array). For comparison just checkout the result in a browser running the same logik: JSON.stringify(Object.keys(document.body.attributes)).

[stale]

Due to our very limited maintenance capacity, we need to prioritize our development focus on other tasks. Therefore, this issue will be automatically closed (see #15395 for more details). In the future, if we see the need to attend to this issue again, then it will be reopened. Thank you for your contribution!