Currently when the QXmlStreamWriter writes an end element while the previously written element was start element (tag is empty), it automatically writes "/>", making a self-closing tag.

Self-closing tags are in html5 acceptable only for void elements (area, base, br, col, command, embed, hr, img, input, keygen, link, meta, param, source, track, wbr).

My suggestion is to add functionality for setting QXmlStreamWriter to html5 compliant mode, which would write end tags ("></ELEMENT NAME>") for non void empty elements.