Fixes

• Avoid misinterpretation of malicious XML input - GHSA-h6q6-9hqw-rwfv (CVE-2021-21366)

  • Improve error reporting; throw on duplicate attribute
    BREAKING CHANGE: It is currently not clear how to consistently deal with duplicate attributes, so it's also safer for our users to fail when detecting them.
    It's possible to configure the DOMParser.errorHandler before parsing, to handle those errors differently.

    To accomplish this and also be able to verify it in tests I needed to

    • create a new Error type ParseError and export it
    • Throw ParseError from errorHandler.fatalError and prevent those from being caught in XMLReader.
    • export DOMHandler constructor as __DOMHandler

  • Preserve quotes in DOCTYPE declaration
    Since the only purpose of parsing the DOCTYPE is to be able to restore it when serializing, we decided that it would be best to leave the parsed publicId and systemId as is, including any quotes.
    BREAKING CHANGE: If somebody relies on the actual unquoted values of those ids, they will need to take care of either single or double quotes and the right escaping.
    (Without this change this would not have been possible because the SAX parser already dropped the information about the quotes that have been used in the source.)

    https://www.w3.org/TR/2006/REC-xml11-20060816/#dtd
    https://www.w3.org/TR/2006/REC-xml11-20060816/#IDAX1KS (External Entity Declaration)

• Fix breaking preprocessors' directives when parsing attributes #171
• fix(dom): Escape ]]> when serializing CharData #181
• Switch to (only) MIT license (drop problematic LGPL license option) #178
• Export DOMException; remove custom assertions; etc. #174

Docs

• Update MDN links in readme.md #188