Notation declarations are incorrectly processed/output by AbstractDomParser::notationDecl
XML spec. does not support both PUBLIC and SYSTEM keywords in the same notation declaration. The presence of PUBLIC implies a system notation so the the SYSTEM keyword is redundant and thus not valid. However, the function (AbstractDomParser::notationDecl) ignores this constraint and outputs the SYSTEM keyword even if PUBLIC keyword was already printed.
Attached is a proposed fix (see lines 1667-1697).