bool HTMLDocument::isCaseSensitiveAttribute( const QualifiedName& attributeName) { static HashSet<StringImpl*>* htmlCaseInsensitiveAttributesSet = createHtmlCaseInsensitiveAttributesSet(); bool isPossibleHTMLAttr = !attributeName.hasPrefix() && (attributeName.namespaceURI() == nullAtom); return !isPossibleHTMLAttr || !htmlCaseInsensitiveAttributesSet->contains( attributeName.localName().impl()); }