Function return values in PHP5.3

Hi Lukas, Johannes Please could I ask for a PHP5.3 release manager's point of view on this? I raised this ext/imap bug yesterday http://bugs.php.net/bug.php?id=46902 after a discussion with Ilia because I noticed that all of the function return values which result from a failure of parameter parsing had changed from 'false' in PHP5.2 to NULL in PHP5.3. So, questions: 1) Is the accepted practice that functions will return NULL when zend_parse_parameters() fails in PHP5.3? 2) Is it acceptable to change the behaviour of functions between 5.2 and 5.3? 3) Does this apply to *all* PHP functions? 4) Assuming that the answer (3) is no, is there any documentation about which functions have changed? (If not would you like some?) Zoë