static/tinymce/plugins/lists/editor_plugin_src.js
function skipWhitespaceNodes(e, next) {
		while (e && (e.nodeType === 8 || (e.nodeType === 3 && /^[ \t\n\r]*$/.test(e.nodeValue)))) {
			e = next(e);
		}
		return e;
	}
function skipWhitespaceNodes(e, next) {
		while (e && (e.nodeType === 8 || (e.nodeType === 3 && /^[ \t\n\r]*$/.test(e.nodeValue)))) {
			e = next(e);
		}
		return e;
	}
Skips text nodes that only contain whitespace since they aren't semantically important.