showDiff needs headers as parameters, even though they aren't needed here. Just give...

diff --git a/includes/Article.php b/includes/Article.php
index cc44187..0cb15a0 100644 (file)
--- a/includes/Article.php
+++ b/includes/Article.php
@@ -2612,7 +2612,7 @@ class Article {
                $wgOut->addHtml( wfMsgExt( 'rollback-success', array( 'parse', 'replaceafter' ), $old, $new ) );
                $wgOut->returnToMain( false, $this->mTitle );
                $de = new DifferenceEngine( $this->mTitle, $current->getId(), 'next', false, true );
-               $de->showDiff();
+               $de->showDiff( '', '' );
        }