From c3704788f97ad34911dea35c92cfe7d05cce6e0a Mon Sep 17 00:00:00 2001
From: =?utf8?q?Niklas=20Laxstr=C3=B6m?= <niklas.laxstrom@gmail.com>
Date: Sat, 6 Dec 2014 10:50:10 +0100
Subject: [PATCH] Skin: handle invalid titles gracefully

Linker::link throws a notice if given null instead of title. Title
is constructed based on messages, so it can easily be null.

Change-Id: I5451135966cbb3bbd09d2568cec6b936f3b88aa3
---
 includes/skins/Skin.php | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/includes/skins/Skin.php b/includes/skins/Skin.php
index ce0c640e10..1a4ec98b18 100644
--- a/includes/skins/Skin.php
+++ b/includes/skins/Skin.php
@@ -482,9 +482,10 @@ abstract class Skin extends ContextSource {
 
 			$msg = $this->msg( 'pagecategories' )->numParams( count( $allCats['normal'] ) )->escaped();
 			$linkPage = wfMessage( 'pagecategorieslink' )->inContentLanguage()->text();
+			$title = Title::newFromText( $linkPage );
+			$link = $title ? Linker::link( $title, $msg ) : $msg;
 			$s .= '<div id="mw-normal-catlinks" class="mw-normal-catlinks">' .
-				Linker::link( Title::newFromText( $linkPage ), $msg )
-				. $colon . '<ul>' . $t . '</ul>' . '</div>';
+				$link . $colon . '<ul>' . $t . '</ul>' . '</div>';
 		}
 
 		# Hidden categories
@@ -951,6 +952,10 @@ abstract class Skin extends ContextSource {
 			// but we make the link target be the one site-wide page.
 			$title = Title::newFromText( $this->msg( $page )->inContentLanguage()->text() );
 
+			if ( !$title ) {
+				return '';
+			}
+
 			return Linker::linkKnown(
 				$title,
 				$this->msg( $desc )->escaped()
-- 
2.20.1