wp-includes/atomlib.php:394$content function xml_escape($content) { return str_replace(array('&','"',"'",'<','>'), array('&','"',''','<','>'), $content ); }Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/atomlib.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.