1 files changed, 80 insertions, 28 deletions

diff --git a/includes/specials/SpecialDoubleRedirects.php b/includes/specials/SpecialDoubleRedirects.php
index 5864ca9f..c364f70f 100644
--- a/includes/specials/SpecialDoubleRedirects.php
+++ b/includes/specials/SpecialDoubleRedirects.php
@@ -28,14 +28,21 @@
  * @ingroup SpecialPage
  */
 class DoubleRedirectsPage extends QueryPage {
-
 	function __construct( $name = 'DoubleRedirects' ) {
 		parent::__construct( $name );
 	}
 
-	function isExpensive() { return true; }
-	function isSyndicated() { return false; }
-	function sortDescending() { return false; }
+	function isExpensive() {
+		return true;
+	}
+
+	function isSyndicated() {
+		return false;
+	}
+
+	function sortDescending() {
+		return false;
+	}
 
 	function getPageHeader() {
 		return $this->msg( 'doubleredirectstext' )->parseAsBlock();
@@ -43,28 +50,52 @@ class DoubleRedirectsPage extends QueryPage {
 
 	function reallyGetQueryInfo( $namespace = null, $title = null ) {
 		$limitToTitle = !( $namespace === null && $title === null );
-		$retval = array (
-			'tables' => array ( 'ra' => 'redirect',
-					'rb' => 'redirect', 'pa' => 'page',
-					'pb' => 'page', 'pc' => 'page' ),
-			'fields' => array ( 'namespace' => 'pa.page_namespace',
-					'title' => 'pa.page_title',
-					'value' => 'pa.page_title',
-					'nsb' => 'pb.page_namespace',
-					'tb' => 'pb.page_title',
-					'nsc' => 'pc.page_namespace',
-					'tc' => 'pc.page_title' ),
-			'conds' => array ( 'ra.rd_from = pa.page_id',
-					'pb.page_namespace = ra.rd_namespace',
-					'pb.page_title = ra.rd_title',
-					'rb.rd_from = pb.page_id',
-					'pc.page_namespace = rb.rd_namespace',
-					'pc.page_title = rb.rd_title' )
+		$dbr = wfGetDB( DB_SLAVE );
+		$retval = array(
+			'tables' => array(
+				'ra' => 'redirect',
+				'rb' => 'redirect',
+				'pa' => 'page',
+				'pb' => 'page'
+			),
+			'fields' => array(
+				'namespace' => 'pa.page_namespace',
+				'title' => 'pa.page_title',
+				'value' => 'pa.page_title',
+
+				'nsb' => 'pb.page_namespace',
+				'tb' => 'pb.page_title',
+
+				// Select fields from redirect instead of page. Because there may
+				// not actually be a page table row for this target (e.g. for interwiki redirects)
+				'nsc' => 'rb.rd_namespace',
+				'tc' => 'rb.rd_title',
+				'iwc' => 'rb.rd_interwiki',
+			),
+			'conds' => array(
+				'ra.rd_from = pa.page_id',
+
+				// Filter out redirects where the target goes interwiki (bug 40353).
+				// This isn't an optimization, it is required for correct results,
+				// otherwise a non-double redirect like Bar -> w:Foo will show up
+				// like "Bar -> Foo -> w:Foo".
+
+				// Need to check both NULL and "" for some reason,
+				// apparently either can be stored for non-iw entries.
+				'ra.rd_interwiki IS NULL OR ra.rd_interwiki = ' . $dbr->addQuotes( '' ),
+
+				'pb.page_namespace = ra.rd_namespace',
+				'pb.page_title = ra.rd_title',
+
+				'rb.rd_from = pb.page_id',
+			)
 		);
+
 		if ( $limitToTitle ) {
 			$retval['conds']['pa.page_namespace'] = $namespace;
 			$retval['conds']['pa.page_title'] = $title;
 		}
+
 		return $retval;
 	}
 
@@ -73,18 +104,35 @@ class DoubleRedirectsPage extends QueryPage {
 	}
 
 	function getOrderFields() {
-		return array ( 'ra.rd_namespace', 'ra.rd_title' );
+		return array( 'ra.rd_namespace', 'ra.rd_title' );
 	}
 
+	/**
+	 * @param Skin $skin
+	 * @param object $result Result row
+	 * @return string
+	 */
 	function formatResult( $skin, $result ) {
 		$titleA = Title::makeTitle( $result->namespace, $result->title );
 
+		// If only titleA is in the query, it means this came from
+		// querycache (which only saves 3 columns).
+		// That does save the bulk of the query cost, but now we need to
+		// get a little more detail about each individual entry quickly
+		// using the filter of reallyGetQueryInfo.
 		if ( $result && !isset( $result->nsb ) ) {
 			$dbr = wfGetDB( DB_SLAVE );
-			$qi = $this->reallyGetQueryInfo( $result->namespace,
-					$result->title );
-			$res = $dbr->select($qi['tables'], $qi['fields'],
-					$qi['conds'], __METHOD__ );
+			$qi = $this->reallyGetQueryInfo(
+				$result->namespace,
+				$result->title
+			);
+			$res = $dbr->select(
+				$qi['tables'],
+				$qi['fields'],
+				$qi['conds'],
+				__METHOD__
+			);
+
 			if ( $res ) {
 				$result = $dbr->fetchObject( $res );
 			}
@@ -94,7 +142,7 @@ class DoubleRedirectsPage extends QueryPage {
 		}
 
 		$titleB = Title::makeTitle( $result->nsb, $result->tb );
-		$titleC = Title::makeTitle( $result->nsc, $result->tc );
+		$titleC = Title::makeTitle( $result->nsc, $result->tc, '', $result->iwc );
 
 		$linkA = Linker::linkKnown(
 			$titleA,
@@ -125,6 +173,10 @@ class DoubleRedirectsPage extends QueryPage {
 		$lang = $this->getLanguage();
 		$arr = $lang->getArrow() . $lang->getDirMark();
 
-		return( "{$linkA} {$edit} {$arr} {$linkB} {$arr} {$linkC}" );
+		return ( "{$linkA} {$edit} {$arr} {$linkB} {$arr} {$linkC}" );
+	}
+
+	protected function getGroupName() {
+		return 'maintenance';
 	}
 }