- SECURITY: Preserve unset options after a _clone() call (e.g: in
load_xml()).
- This caused expand_entities(0) to not be preserved/etc.
- This is a security problem which was assigned the CVE number of
CVE-2015-3451 .
- Thanks to Tilmann Haak from xing.com for the report.
- This caused expand_entities(0) to not be preserved/etc.