in ext/syntaxhighlighter/scripts/XRegExp.js [485:497]
function clone (regex, additionalFlags) {
if (!XRegExp.isRegExp(regex))
throw TypeError("type RegExp expected");
var x = regex._xregexp;
regex = XRegExp(regex.source, getNativeFlags(regex) + (additionalFlags || ""));
if (x) {
regex._xregexp = {
source: x.source,
captureNames: x.captureNames ? x.captureNames.slice(0) : null
};
}
return regex;
};