feedapi_invoke() call from menu_execute_active_handler() fails on node/<nid>/purge page

I'm running php 5.3.4, and when I go to the node/%node/purge page, the following php error gets thrown:

Warning: Parameter 2 to feedapi_invoke() expected to be a reference, value given in menu_execute_active_handler() (line 349 of /Library/WebServer/Documents/hci/includes/menu.inc).

resulting in a blank page.

Function definition is:

function feedapi_invoke($op, &$feed, $param = NULL)

so $feed is expected to be a reference, whereas it is not.

Per http://php.net/manual/en/function.call-user-func-array.php:

Passing by value when the function expects a parameter by reference results in a warning and having call_user_func() return FALSE (does not apply if the passed value has a reference count = 1).

Suggestions on the best approach to correct the bug? I know that if the function definition is changed to:

function feedapi_invoke($op, $feed, $param = NULL)

the purge operation succeeds without errors, but I'm not sure about other ramifications. I.e. are there good reasons to pass $feed by reference?