HTMLDOC before 1.9.19 has an out-of-bounds write in parse_paragraph in ps-pdf.cxx because of an attempt to strip leading whitespace from a whitespace-only node.
https://github.com/michaelrsweet/htmldoc/issues/528
https://github.com/michaelrsweet/htmldoc/commit/2d5b2ab9ddbf2aee2209010cebc11efdd1cab6e2
https://github.com/michaelrsweet/htmldoc/blob/2d5b2ab9ddbf2aee2209010cebc11efdd1cab6e2/CHANGES.md