Steps to Reproduce

Add DOCTYPE xml declaration to zk.xml should cause the SAX parser to refuse to parse the file

<!DOCTYPE xml>

Current Result

No restriction

Expected Result

on-purpose restriction cause parsing exception

org.xml.sax.SAXParseException: DOCTYPE is disallowed when the feature http://apache.org/xml/features/disallow-doctype-decl set to true.

Debug Information

Caused by setting which explicitly disallow DOCTYPE in parsed files
https://xerces.apache.org/xerces2-j/features.html#disallow-doctype-decl
https://github.com/zkoss/zk/commit/8a94e3e730d1486348115e87892d26ec560f9d25

Workaround for existing files

remove DOCTYPE declaration from xml files