This patch fixes it:

• a/includes/LinkBatch.php

+++ b/includes/LinkBatch.php
@@ -72,7 +72,7 @@ class LinkBatch {

• • Do the query and add the results to a given LinkCache object
  • Return an array mapping PDBK to ID */
• protected function executeInto( &$cache ) {

+ public function executeInto( &$cache ) {

wfProfileIn( __METHOD__ );
$res = $this->doQuery();
$ids = $this->addResultToCache( $cache, $res );

"protected" was introduced here in r33025. Not sure why it was done, as both doQuery() and addResultToCache() are public. Suggested fix: Change to "public" as in the patch above.

This extension no longer exists in the MediaWiki Subversion repository as it was marked obsolete in December 2007 and removed in August 2008. Development has continued for a long while already outside of the repo. This request is now INVALID.