From bfa21200c7f23a0bbc0654bbd8c4138fe03886c0 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Szymon=20=C5=9Awierkosz?= <beau@adres.pl>
Date: Sat, 31 Mar 2012 17:26:50 +0200
Subject: [PATCH] (bug 21796) Fix null dereference on Special:Undelete.

This change allows to display deleted pages correctly without dereferencing
a null. It is still impossible to view or undelete a page with an invalid
title, so the title is a shown as plain text.

Change-Id: Ib82d385eb174dac5e559736920cdb21303291ad2
---
 includes/specials/SpecialUndelete.php | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/includes/specials/SpecialUndelete.php b/includes/specials/SpecialUndelete.php
index e8f3df7243..06b578d701 100644
--- a/includes/specials/SpecialUndelete.php
+++ b/includes/specials/SpecialUndelete.php
@@ -745,14 +745,20 @@ class SpecialUndelete extends SpecialPage {
 		$out->addHTML( "<ul>\n" );
 		foreach ( $result as $row ) {
 			$title = Title::makeTitleSafe( $row->ar_namespace, $row->ar_title );
-			$link = Linker::linkKnown(
-				$undelete,
-				htmlspecialchars( $title->getPrefixedText() ),
-				array(),
-				array( 'target' => $title->getPrefixedText() )
-			);
+			if ( $title !== null ) {
+				$item = Linker::linkKnown(
+					$undelete,
+					htmlspecialchars( $title->getPrefixedText() ),
+					array(),
+					array( 'target' => $title->getPrefixedText() )
+				);
+			} else {
+				// The title is no longer valid, show as text
+				$title = Title::makeTitle( $row->ar_namespace, $row->ar_title );
+				$item = htmlspecialchars( $title->getPrefixedText() );
+			}
 			$revs = $this->msg( 'undeleterevisions' )->numParams( $row->count )->parse();
-			$out->addHTML( "<li>{$link} ({$revs})</li>\n" );
+			$out->addHTML( "<li>{$item} ({$revs})</li>\n" );
 		}
 		$result->free();
 		$out->addHTML( "</ul>\n" );
-- 
2.20.1