Parsoid's output is supposed to be both valid HTML and valid XML. But https://rest.wikimedia.org/en.wikipedia.org/v1/page/html/Microsoft/653066299 is not valid XML, because it contains a comment like <!-- foo--bar --> which is valid HTML but not valid XML.
This breaks https://en.wikipedia.org/wiki/Microsoft?oldid=653066299&veaction=edit in Internet Explorer, because we use an XML parser to work around IE's many attribute normalization bugs.
> $.ajax({ url: 'https://rest.wikimedia.org/en.wikipedia.org/v1/page/html/Microsoft/653066299', dataType: 'text' } ).done( function(text) { window.doc = new DOMParser().parseFromString(text, 'text/xml'); console.log(window.doc); });
Object {readyState: 1, getResponseHeader: function, getAllResponseHeaders: function, setRequestHeader: function, overrideMimeType: function…}
> window.doc.getElementsByTagName('parsererror')[0].innerHTML
"<h3 xmlns="http://www.w3.org/1999/xhtml">This page contains the following errors:</h3><div xmlns="http://www.w3.org/1999/xhtml" style="font-family:monospace;font-size:12px">error on line 102 at column 1469: Comment not terminated
<!-- Generally we stick to products that are in the cu
</div><h3 xmlns="http://www.w3.org/1999/xhtml">Below is a rendering of the page up to the first error.</h3>"
> window.xml.indexOf('Generally we stick')
83002
> window.xml.slice(82990, 83200)
"/span> <!-- Generally we stick to products that are in the current annual report here--if you wish to add one that is not you need to provide a reference for it -->For the 2010 <a rel="mw:WikiLink" href="./Fisc"