Function isDisconnected

documentation/javascript/application.js:6253–6255

( node )

// A painfully simple check to see if an element is disconnected
// from a document (should be improved, where feasible).
function isDisconnected( node ) {
	return !node || !node.parentNode || node.parentNode.nodeType === 11;
}

function sibling( cur, dir ) {
	do {