From 147ec4cad8b591831eec2c84a73f60e66abf0847 Mon Sep 17 00:00:00 2001
From: Kunal Mehta <legoktm@member.fsf.org>
Date: Thu, 12 May 2016 11:25:51 -0700
Subject: [PATCH] TitleFormatter: Match Title behavior for non-existent
 namespaces

In TitleFormatter::getPrefixedDBkey(), match the
Title::getPrefixedDBkey() behavior for non-existent namespaces by using
an empty string for the namespace and including a leading colon.

Change-Id: I195c36df69963c7409711dd97bece078f61faf77
---
 includes/title/MediaWikiTitleCodec.php           | 16 +++++++++++-----
 .../includes/title/MediaWikiTitleCodecTest.php   |  5 ++++-
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/includes/title/MediaWikiTitleCodec.php b/includes/title/MediaWikiTitleCodec.php
index 5c504f3513..38e9ecdacf 100644
--- a/includes/title/MediaWikiTitleCodec.php
+++ b/includes/title/MediaWikiTitleCodec.php
@@ -192,12 +192,18 @@ class MediaWikiTitleCodec implements TitleFormatter, TitleParser {
 		if ( $target->isExternal() ) {
 			$key .= $target->getInterwiki() . ':';
 		}
-		$nsName = $this->getNamespaceName(
-			$target->getNamespace(),
-			$target->getText()
-		);
+		// Try to get a namespace name, but fallback
+		// to empty string if it doesn't exist
+		try {
+			$nsName = $this->getNamespaceName(
+				$target->getNamespace(),
+				$target->getText()
+			);
+		} catch ( InvalidArgumentException $e ) {
+			$nsName = '';
+		}
 
-		if ( $nsName !== '' ) {
+		if ( $target->getNamespace() !== 0 ) {
 			$key .= $nsName . ':';
 		}
 
diff --git a/tests/phpunit/includes/title/MediaWikiTitleCodecTest.php b/tests/phpunit/includes/title/MediaWikiTitleCodecTest.php
index 40065f559e..e55a3a4438 100644
--- a/tests/phpunit/includes/title/MediaWikiTitleCodecTest.php
+++ b/tests/phpunit/includes/title/MediaWikiTitleCodecTest.php
@@ -191,7 +191,10 @@ class MediaWikiTitleCodecTest extends MediaWikiTestCase {
 			// names ending in "a" to be female.
 			[ NS_USER, 'Lisa_Müller', '', '', 'de', 'Benutzerin:Lisa_Müller' ],
 
-			[ NS_MAIN, 'Remote_page', '', 'remotetestiw', 'en', 'remotetestiw:Remote_page' ]
+			[ NS_MAIN, 'Remote_page', '', 'remotetestiw', 'en', 'remotetestiw:Remote_page' ],
+
+			// non-existent namespace
+			[ 10000000, 'Foobar', '', '', 'en', ':Foobar' ],
 		];
 	}
 
-- 
2.20.1