Replace x() by isset(), !empty() or defaults()

- Remove extraneous parentheses around empty() calls
- Remove duplicate calls to intval(), count() or strlen() after empty()
- Replace ternary operators outputting binary value with empty() return value
- Rewrite defaults() without x()

src/Core/Session/DatabaseSessionHandler.php

@@ -26,7 +26,7 @@ class DatabaseSessionHandler extends BaseObject implements SessionHandlerInterfa
 
 	public function read($session_id)
 	{
-		if (!x($session_id)) {
+		if (empty($session_id)) {
 			return '';
 		}