From 24c000ea804d3a730b96bf71d40e1ef5d7241105 Mon Sep 17 00:00:00 2001
From: Kunal Mehta <legoktm@gmail.com>
Date: Thu, 4 Dec 2014 17:45:05 -0800
Subject: [PATCH] Add and use Title::getOtherPage()

Change-Id: I40a51c14ce07c301c15c6c2128cc18bb12e71103
---
 includes/Title.php                          | 19 +++++++++++++++
 includes/page/WikiPage.php                  | 12 ++--------
 tests/phpunit/includes/TitleMethodsTest.php | 26 +++++++++++++++++++++
 3 files changed, 47 insertions(+), 10 deletions(-)

diff --git a/includes/Title.php b/includes/Title.php
index 638da08581..562fc54556 100644
--- a/includes/Title.php
+++ b/includes/Title.php
@@ -1335,6 +1335,25 @@ class Title {
 		return Title::makeTitle( $subjectNS, $this->getDBkey() );
 	}
 
+	/**
+	 * Get the other title for this page, if this is a subject page
+	 * get the talk page, if it is a subject page get the talk page
+	 *
+	 * @since 1.25
+	 * @throws MWException
+	 * @return Title
+	 */
+	public function getOtherPage() {
+		if ( $this->isSpecialPage() ) {
+			throw new MWException( 'Special pages cannot have other pages' );
+		}
+		if ( $this->isTalkPage() ) {
+			return $this->getSubjectPage();
+		} else {
+			return $this->getTalkPage();
+		}
+	}
+
 	/**
 	 * Get the default namespace index, for when there is no namespace
 	 *
diff --git a/includes/page/WikiPage.php b/includes/page/WikiPage.php
index 8b26c2319c..31d6fc8f56 100644
--- a/includes/page/WikiPage.php
+++ b/includes/page/WikiPage.php
@@ -3158,11 +3158,7 @@ class WikiPage implements Page, IDBAccessObject {
 	 */
 	public static function onArticleCreate( $title ) {
 		// Update existence markers on article/talk tabs...
-		if ( $title->isTalkPage() ) {
-			$other = $title->getSubjectPage();
-		} else {
-			$other = $title->getTalkPage();
-		}
+		$other = $title->getOtherPage();
 
 		$other->invalidateCache();
 		$other->purgeSquid();
@@ -3179,11 +3175,7 @@ class WikiPage implements Page, IDBAccessObject {
 	 */
 	public static function onArticleDelete( $title ) {
 		// Update existence markers on article/talk tabs...
-		if ( $title->isTalkPage() ) {
-			$other = $title->getSubjectPage();
-		} else {
-			$other = $title->getTalkPage();
-		}
+		$other = $title->getOtherPage();
 
 		$other->invalidateCache();
 		$other->purgeSquid();
diff --git a/tests/phpunit/includes/TitleMethodsTest.php b/tests/phpunit/includes/TitleMethodsTest.php
index 5904facd07..707a4a1c0b 100644
--- a/tests/phpunit/includes/TitleMethodsTest.php
+++ b/tests/phpunit/includes/TitleMethodsTest.php
@@ -297,4 +297,30 @@ class TitleMethodsTest extends MediaWikiTestCase {
 		$title = Title::newFromText( $title );
 		$this->assertEquals( $expectedBool, $title->isWikitextPage() );
 	}
+
+	public static function provideGetOtherPage() {
+		return array(
+			array( 'Main Page', 'Talk:Main Page' ),
+			array( 'Talk:Main Page', 'Main Page' ),
+			array( 'Help:Main Page', 'Help talk:Main Page' ),
+			array( 'Help talk:Main Page', 'Help:Main Page' ),
+			array( 'Special:FooBar', null ),
+		);
+	}
+
+	/**
+	 * @dataProvider provideGetOtherpage
+	 * @covers Title::getOtherPage
+	 *
+	 * @param string $text
+	 * @param string|null $expected
+	 */
+	public function testGetOtherPage( $text, $expected ) {
+		if ( $expected === null ) {
+			$this->setExpectedException( 'MWException' );
+		}
+
+		$title = Title::newFromText( $text );
+		$this->assertEquals( $expected, $title->getOtherPage()->getPrefixedText() );
+	}
 }
-- 
2.20.1