From 396e18a8e572ad350ce501492e8bf15d54ab6138 Mon Sep 17 00:00:00 2001
From: Liangent <liangent@gmail.com>
Date: Fri, 7 Jun 2013 08:50:10 +0000
Subject: [PATCH] New function Language::getParentLanguage().

Change-Id: Ib2109176b7dfc7ec2d0ee827c804cf93ea83b9e5
---
 languages/Language.php                   | 33 ++++++++++++++++++++++--
 tests/phpunit/languages/LanguageTest.php | 22 ++++++++++++++++
 2 files changed, 53 insertions(+), 2 deletions(-)

diff --git a/languages/Language.php b/languages/Language.php
index 92ea75c814..ead72c6bd0 100644
--- a/languages/Language.php
+++ b/languages/Language.php
@@ -81,7 +81,7 @@ class Language {
 
 	public $mVariants, $mCode, $mLoaded = false;
 	public $mMagicExtensions = array(), $mMagicHookDone = false;
-	private $mHtmlCode = null;
+	private $mHtmlCode = null, $mParentLanguage = false;
 
 	public $dateFormatStrings = array();
 	public $mExtendedSpecialPageAliases;
@@ -3933,6 +3933,34 @@ class Language {
 		return $this;
 	}
 
+	/**
+	 * Get the "parent" language which has a converter to convert a "compatible" language
+	 * (in another variant) to this language (eg. zh for zh-cn, but not en for en-gb).
+	 *
+	 * @return Language|null
+	 * @since 1.22
+	 */
+	public function getParentLanguage() {
+		if ( $this->mParentLanguage !== false ) {
+			return $this->mParentLanguage;
+		}
+
+		$pieces = explode( '-', $this->getCode() );
+		$code = $pieces[0];
+		if ( !in_array( $code, LanguageConverter::$languagesWithVariants ) ) {
+			$this->mParentLanguage = null;
+			return null;
+		}
+		$lang = Language::factory( $code );
+		if ( !$lang->hasVariant( $this->getCode() ) ) {
+			$this->mParentLanguage = null;
+			return null;
+		}
+
+		$this->mParentLanguage = $lang;
+		return $lang;
+	}
+
 	/**
 	 * Get the RFC 3066 code for this language object
 	 *
@@ -3967,8 +3995,9 @@ class Language {
 	 */
 	public function setCode( $code ) {
 		$this->mCode = $code;
-		// Ensure we don't leave an incorrect html code lying around
+		// Ensure we don't leave incorrect cached data lying around
 		$this->mHtmlCode = null;
+		$this->mParentLanguage = false;
 	}
 
 	/**
diff --git a/tests/phpunit/languages/LanguageTest.php b/tests/phpunit/languages/LanguageTest.php
index d687dbbd93..4d67f45dd7 100644
--- a/tests/phpunit/languages/LanguageTest.php
+++ b/tests/phpunit/languages/LanguageTest.php
@@ -1481,4 +1481,26 @@ class LanguageTest extends LanguageClassesTestCase {
 			array( 'FI', false, 'is not supported language, input should be in lower case' ),
 		);
 	}
+
+	/**
+	 * @dataProvider provideGetParentLanguage
+	 */
+	function testGetParentLanguage( $code, $expected, $comment ) {
+		$lang = Language::factory( $code );
+		if ( is_null( $expected ) ) {
+			$this->assertNull( $lang->getParentLanguage(), $comment );
+		} else {
+			$this->assertEquals( $expected, $lang->getParentLanguage()->getCode(), $comment );
+		}
+	}
+
+	public static function provideGetParentLanguage() {
+		return array(
+			array( 'zh-cn', 'zh', 'zh is the parent language of zh-cn' ),
+			array( 'zh', 'zh', 'zh is defined as the parent language of zh, because zh converter can convert zh-cn to zh' ),
+			array( 'zh-invalid', null, 'do not be fooled by arbitrarily composed language codes' ),
+			array( 'en-gb', null, 'en does not have converter' ),
+			array( 'en', null, 'en does not have converter. Although FakeConverter handles en -> en conversion but it is useless' ),
+		);
+	}
 }
-- 
2.20.1