[Mediawiki-l] Determine if user logged in and then remove edit

[Platonides]

Fast an dirty way, put at the beginning of editSectionLink and 
editSectionLinkForOther (at Linker.php)

global $wgUser;
if (!$wgUser->isLoggedIn())
   return "";

(you will also need to disable the parser cache or take into account the 
loggedness)