parse attribute "constructor" crash

[Particle60]

if a node has an attribute "constructor", xmldom will crash. For Example:

<?xml version="1.0" encoding="UTF-8"?>
<cofluent:Application >
    <refinement>
        <models constructor="printf(&quot;hello\n&quot;);" >
        </models>
    </refinement>
</cofluent:Application>

The bug is in lib/sax.js

function parseElementStartPart(source,start,el,currentNSMap,entityReplacer,errorHandler){

	/**
	 * @param {string} qname
	 * @param {string} value
	 * @param {number} startIndex
	 */
	function addAttribute(qname, value, startIndex) {
		if (qname in el.attributeNames) errorHandler.fatalError('Attribute ' + qname + ' redefined')
		el.addValue(qname, value, startIndex)
	}

(qname in el.attributeNames) will return true even el.attributeNames === {}.
"constructor" in {} will return true.

[karfau]

Thank you for reporting it, but I wonder what version of xmldom (or rather @xmldom/xmldom) you are using, since this was fixed in #315 and released in version 0.7.4 (4 months ago).

See the current version of the code

And I verified that your XML can be parsed in 0.7.4: https://stackblitz.com/edit/js-xmldom359?devtoolsheight=33&file=index.js
And checked that the issue is present in xmldom@>=0.5.0 and @xmldom/xmldom@<0.7.4.