From 52def2f997d8f00561e9d6262844c040d63a35d8 Mon Sep 17 00:00:00 2001
From: Tim Starling <tstarling@users.mediawiki.org>
Date: Tue, 4 May 2004 12:37:29 +0000
Subject: [PATCH] Interwiki redirects using prefixes in the URL

---
 includes/DefaultSettings.php |  1 +
 includes/Title.php           | 36 +++++++++++++++++++++++++-----------
 index.php                    | 11 ++++++++++-
 3 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/includes/DefaultSettings.php b/includes/DefaultSettings.php
index 5a83e4cd10..ec7ce9f0a4 100644
--- a/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@ -108,6 +108,7 @@ $wgAmericanDates    = false; # Enable for English module to print dates
 $wgLocalInterwiki   = "w";
 $wgShowIPinHeader	= true; # For non-logged in users
 $wgMaxNameChars     = 32; # Maximum number of bytes in username
+$wgInterwikiExpiry = 10800; # Expiry time for cache of interwiki table
 
 # Translation using MediaWiki: namespace
 # This will increase load times by 25-60% unless memcached is installed
diff --git a/includes/Title.php b/includes/Title.php
index cd55e7420e..b387d172b9 100644
--- a/includes/Title.php
+++ b/includes/Title.php
@@ -1,7 +1,7 @@
 <?php
 # See title.doc
 
-/* private static */ $title_interwiki_cache = array();
+$wgTitleInterwikiCache = array();
 
 # Title class
 # 
@@ -238,21 +238,22 @@ class Title {
 	# The URL contains $1, which is replaced by the title
 	function getInterwikiLink( $key )
 	{	
-		global $wgMemc, $wgDBname;
-		static $title_interwiki_cache = array();
+		global $wgMemc, $wgDBname, $wgInterwikiExpiry;
+		static $wgTitleInterwikiCache = array();
 
 		$k = "$wgDBname:interwiki:$key";
 
-		if( array_key_exists( $k, $title_interwiki_cache ) )
-			return $title_interwiki_cache[$k]->iw_url;
+		if( array_key_exists( $k, $wgTitleInterwikiCache ) )
+			return $wgTitleInterwikiCache[$k]->iw_url;
 
 		$s = $wgMemc->get( $k ); 
-		if( $s ) { 
-			$title_interwiki_cache[$k] = $s;
+		# Ignore old keys with no iw_local
+		if( $s && isset( $s->iw_local ) ) { 
+			$wgTitleInterwikiCache[$k] = $s;
 			return $s->iw_url;
 		}
 		$dkey = wfStrencode( $key );
-		$query = "SELECT iw_url FROM interwiki WHERE iw_prefix='$dkey'";
+		$query = "SELECT iw_url,iw_local FROM interwiki WHERE iw_prefix='$dkey'";
 		$res = wfQuery( $query, DB_READ, "Title::getInterwikiLink" );
 		if(!$res) return "";
 		
@@ -261,11 +262,24 @@ class Title {
 			$s = (object)false;
 			$s->iw_url = "";
 		}
-		$wgMemc->set( $k, $s );
-		$title_interwiki_cache[$k] = $s;
+		$wgMemc->set( $k, $s, $wgInterwikiExpiry );
+		$wgTitleInterwikiCache[$k] = $s;
 		return $s->iw_url;
 	}
-	
+
+	function isLocal() {
+		global $wgTitleInterwikiCache, $wgDBname;
+
+		if ( $this->mInterwiki != "" ) {
+			# Make sure key is loaded into cache
+			$this->getInterwikiLink( $this->mInterwiki );
+			$k = "$wgDBname:interwiki:" . $this->mInterwiki;
+			return (bool)($wgTitleInterwikiCache[$k]->iw_local);
+		} else {
+			return true;
+		}
+	}
+
 	# Update the cur_touched field for an array of title objects
 	# Inefficient unless the IDs are already loaded into the link cache
 	/* static */ function touchArray( $titles, $timestamp = "" ) {
diff --git a/index.php b/index.php
index 0d54b6b2f4..7f66557c12 100644
--- a/index.php
+++ b/index.php
@@ -70,9 +70,18 @@ if ( $search = $wgRequest->getText( 'search' ) ) {
 	} else {
 		wfGo( $search );
 	}
-} else if( !$wgTitle or $wgTitle->getInterwiki() != "" or $wgTitle->getDBkey() == "" ) {
+} else if( !$wgTitle or $wgTitle->getDBkey() == "" ) {
 	$wgTitle = Title::newFromText( wfMsg( "badtitle" ) );
 	$wgOut->errorpage( "badtitle", "badtitletext" );
+} else if ( $wgTitle->getInterwiki() != "" ) {
+	$url = $wgTitle->getFullURL();
+	# Check for a redirect loop
+	if ( !preg_match( "/^" . preg_quote( $wgServer ) . "/", $url ) && $wgTitle->isLocal() ) {
+		$wgOut->redirect( $url );
+	} else {
+		$wgTitle = Title::newFromText( wfMsg( "badtitle" ) );
+		$wgOut->errorpage( "badtitle", "badtitletext" );
+	}
 } else if ( ( $action == "view" ) && $wgTitle->getPrefixedDBKey() != $title ) {
 	/* redirect to canonical url, make it a 301 to allow caching */
 	$wgOut->redirect( $wgTitle->getFullURL(), '301');
-- 
2.20.1