ZF-9696: Interface Zend_Loader_Autoloader_Interface - incorrect return type for autoload() method
PhpDoc for method Zend_Loader_Autoloader_Interface::autoload() is missing. One of the most important information is missing - that one, that method autoload() is supposed to return boolean value, TRUE if it has found $class. It can have significant influence on performance.
This non-documented feature comes up from analyzing Zend_Loader_Autoloader::autoload() method.