* (bug 9556) Update Bulgarian translations

[mediawiki.git] / includes / Title.php

<?php
/**
 * See title.txt
 *
 */

/** */
if ( !class_exists( 'UtfNormal' ) ) {
        require_once( dirname(__FILE__) . '/normal/UtfNormal.php' );
}

define ( 'GAID_FOR_UPDATE', 1 );

# Title::newFromTitle maintains a cache to avoid
# expensive re-normalization of commonly used titles.
# On a batch operation this can become a memory leak
# if not bounded. After hitting this many titles,
# reset the cache.
define( 'MW_TITLECACHE_MAX', 1000 );

# Constants for pr_cascade bitfield
define( 'CASCADE', 1 );

/**
 * Title class
 * - Represents a title, which may contain an interwiki designation or namespace
 * - Can fetch various kinds of data from the database, albeit inefficiently.
 *
 */
class Title {
        /**
         * Static cache variables
         */
        static private $titleCache=array();
        static private $interwikiCache=array();
        
        
        /**
         * All member variables should be considered private
         * Please use the accessor functions
         */

         /**#@+
         * @private
         */

        var $mTextform;                 # Text form (spaces not underscores) of the main part
        var $mUrlform;                  # URL-encoded form of the main part
        var $mDbkeyform;                # Main part with underscores
        var $mNamespace;                # Namespace index, i.e. one of the NS_xxxx constants
        var $mInterwiki;                # Interwiki prefix (or null string)
        var $mFragment;                 # Title fragment (i.e. the bit after the #)
        var $mArticleID;                # Article ID, fetched from the link cache on demand
        var $mLatestID;                 # ID of most recent revision
        var $mRestrictions;             # Array of groups allowed to edit this article
        var $mCascadeRestriction;       # Cascade restrictions on this page to included templates and images?
        var $mRestrictionsExpiry;       # When do the restrictions on this page expire?
        var $mHasCascadingRestrictions; # Are cascading restrictions in effect on this page?
        var $mCascadeRestrictionSources;# Where are the cascading restrictions coming from on this page?
        var $mRestrictionsLoaded;       # Boolean for initialisation on demand
        var $mPrefixedText;             # Text form including namespace/interwiki, initialised on demand
        var $mDefaultNamespace;         # Namespace index when there is no namespace
                                        # Zero except in {{transclusion}} tags
        var $mWatched;                  # Is $wgUser watching this page? NULL if unfilled, accessed through userIsWatching()
        /**#@-*/


        /**
         * Constructor
         * @private
         */
        /* private */ function __construct() {
                $this->mInterwiki = $this->mUrlform =
                $this->mTextform = $this->mDbkeyform = '';
                $this->mArticleID = -1;
                $this->mNamespace = NS_MAIN;
                $this->mRestrictionsLoaded = false;
                $this->mRestrictions = array();
                # Dont change the following, NS_MAIN is hardcoded in several place
                # See bug #696
                $this->mDefaultNamespace = NS_MAIN;
                $this->mWatched = NULL;
                $this->mLatestID = false;
                $this->mOldRestrictions = false;
        }

        /**
         * Create a new Title from a prefixed DB key
         * @param string $key The database key, which has underscores
         *      instead of spaces, possibly including namespace and
         *      interwiki prefixes
         * @return Title the new object, or NULL on an error
         * @static
         * @access public
         */
        /* static */ function newFromDBkey( $key ) {
                $t = new Title();
                $t->mDbkeyform = $key;
                if( $t->secureAndSplit() )
                        return $t;
                else
                        return NULL;
        }

        /**
         * Create a new Title from text, such as what one would
         * find in a link. Decodes any HTML entities in the text.
         *
         * @param string $text the link text; spaces, prefixes,
         *      and an initial ':' indicating the main namespace
         *      are accepted
         * @param int $defaultNamespace the namespace to use if
         *      none is specified by a prefix
         * @return Title the new object, or NULL on an error
         * @static
         * @access public
         */
        public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
                if( is_object( $text ) ) {
                        throw new MWException( 'Title::newFromText given an object' );
                }

                /**
                 * Wiki pages often contain multiple links to the same page.
                 * Title normalization and parsing can become expensive on
                 * pages with many links, so we can save a little time by
                 * caching them.
                 *
                 * In theory these are value objects and won't get changed...
                 */
                if( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
                        return Title::$titleCache[$text];
                }

                /**
                 * Convert things like &eacute; &#257; or &#x3017; into real text...
                 */
                $filteredText = Sanitizer::decodeCharReferences( $text );

                $t = new Title();
                $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
                $t->mDefaultNamespace = $defaultNamespace;

                static $cachedcount = 0 ;
                if( $t->secureAndSplit() ) {
                        if( $defaultNamespace == NS_MAIN ) {
                                if( $cachedcount >= MW_TITLECACHE_MAX ) {
                                        # Avoid memory leaks on mass operations...
                                        Title::$titleCache = array();
                                        $cachedcount=0;
                                }
                                $cachedcount++;
                                Title::$titleCache[$text] =& $t;
                        }
                        return $t;
                } else {
                        $ret = NULL;
                        return $ret;
                }
        }

        /**
         * Create a new Title from URL-encoded text. Ensures that
         * the given title's length does not exceed the maximum.
         * @param string $url the title, as might be taken from a URL
         * @return Title the new object, or NULL on an error
         * @static
         * @access public
         */
        public static function newFromURL( $url ) {
                global $wgLegalTitleChars;
                $t = new Title();

                # For compatibility with old buggy URLs. "+" is usually not valid in titles,
                # but some URLs used it as a space replacement and they still come
                # from some external search tools.
                if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
                        $url = str_replace( '+', ' ', $url );
                }

                $t->mDbkeyform = str_replace( ' ', '_', $url );
                if( $t->secureAndSplit() ) {
                        return $t;
                } else {
                        return NULL;
                }
        }

        /**
         * Create a new Title from an article ID
         *
         * @todo This is inefficiently implemented, the page row is requested
         *       but not used for anything else
         *
         * @param int $id the page_id corresponding to the Title to create
         * @return Title the new object, or NULL on an error
         * @access public
         * @static
         */
        public static function newFromID( $id ) {
                $fname = 'Title::newFromID';
                $dbr = wfGetDB( DB_SLAVE );
                $row = $dbr->selectRow( 'page', array( 'page_namespace', 'page_title' ),
                        array( 'page_id' => $id ), $fname );
                if ( $row !== false ) {
                        $title = Title::makeTitle( $row->page_namespace, $row->page_title );
                } else {
                        $title = NULL;
                }
                return $title;
        }

        /**
         * Make an array of titles from an array of IDs 
         */
        function newFromIDs( $ids ) {
                $dbr = wfGetDB( DB_SLAVE );
                $res = $dbr->select( 'page', array( 'page_namespace', 'page_title' ),
                        'page_id IN (' . $dbr->makeList( $ids ) . ')', __METHOD__ );

                $titles = array();
                while ( $row = $dbr->fetchObject( $res ) ) {
                        $titles[] = Title::makeTitle( $row->page_namespace, $row->page_title );
                }
                return $titles;
        }

        /**
         * Create a new Title from a namespace index and a DB key.
         * It's assumed that $ns and $title are *valid*, for instance when
         * they came directly from the database or a special page name.
         * For convenience, spaces are converted to underscores so that
         * eg user_text fields can be used directly.
         *
         * @param int $ns the namespace of the article
         * @param string $title the unprefixed database key form
         * @return Title the new object
         * @static
         * @access public
         */
        public static function &makeTitle( $ns, $title ) {
                $t = new Title();
                $t->mInterwiki = '';
                $t->mFragment = '';
                $t->mNamespace = intval( $ns );
                $t->mDbkeyform = str_replace( ' ', '_', $title );
                $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
                $t->mUrlform = wfUrlencode( $t->mDbkeyform );
                $t->mTextform = str_replace( '_', ' ', $title );
                return $t;
        }

        /**
         * Create a new Title from a namespace index and a DB key.
         * The parameters will be checked for validity, which is a bit slower
         * than makeTitle() but safer for user-provided data.
         *
         * @param int $ns the namespace of the article
         * @param string $title the database key form
         * @return Title the new object, or NULL on an error
         * @static
         * @access public
         */
        public static function makeTitleSafe( $ns, $title ) {
                $t = new Title();
                $t->mDbkeyform = Title::makeName( $ns, $title );
                if( $t->secureAndSplit() ) {
                        return $t;
                } else {
                        return NULL;
                }
        }

        /**
         * Create a new Title for the Main Page
         *
         * @static
         * @return Title the new object
         * @access public
         */
        public static function newMainPage() {
                return Title::newFromText( wfMsgForContent( 'mainpage' ) );
        }

        /**
         * Create a new Title for a redirect
         * @param string $text the redirect title text
         * @return Title the new object, or NULL if the text is not a
         *      valid redirect
         */
        public static function newFromRedirect( $text ) {
                $mwRedir = MagicWord::get( 'redirect' );
                $rt = NULL;
                if ( $mwRedir->matchStart( $text ) ) {
                        $m = array();
                        if ( preg_match( '/\[{2}(.*?)(?:\||\]{2})/', $text, $m ) ) {
                                # categories are escaped using : for example one can enter:
                                # #REDIRECT [[:Category:Music]]. Need to remove it.
                                if ( substr($m[1],0,1) == ':') {
                                        # We don't want to keep the ':'
                                        $m[1] = substr( $m[1], 1 );
                                }

                                $rt = Title::newFromText( $m[1] );
                                # Disallow redirects to Special:Userlogout
                                if ( !is_null($rt) && $rt->isSpecial( 'Userlogout' ) ) {
                                        $rt = NULL;
                                }
                        }
                }
                return $rt;
        }

#----------------------------------------------------------------------------
#       Static functions
#----------------------------------------------------------------------------

        /**
         * Get the prefixed DB key associated with an ID
         * @param int $id the page_id of the article
         * @return Title an object representing the article, or NULL
         *      if no such article was found
         * @static
         * @access public
         */
        function nameOf( $id ) {
                $fname = 'Title::nameOf';
                $dbr = wfGetDB( DB_SLAVE );

                $s = $dbr->selectRow( 'page', array( 'page_namespace','page_title' ),  array( 'page_id' => $id ), $fname );
                if ( $s === false ) { return NULL; }

                $n = Title::makeName( $s->page_namespace, $s->page_title );
                return $n;
        }

        /**
         * Get a regex character class describing the legal characters in a link
         * @return string the list of characters, not delimited
         * @static
         * @access public
         */
        public static function legalChars() {
                global $wgLegalTitleChars;
                return $wgLegalTitleChars;
        }

        /**
         * Get a string representation of a title suitable for
         * including in a search index
         *
         * @param int $ns a namespace index
         * @param string $title text-form main part
         * @return string a stripped-down title string ready for the
         *      search index
         */
        public static function indexTitle( $ns, $title ) {
                global $wgContLang;

                $lc = SearchEngine::legalSearchChars() . '&#;';
                $t = $wgContLang->stripForSearch( $title );
                $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
                $t = $wgContLang->lc( $t );

                # Handle 's, s'
                $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
                $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );

                $t = preg_replace( "/\\s+/", ' ', $t );

                if ( $ns == NS_IMAGE ) {
                        $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
                }
                return trim( $t );
        }

        /*
         * Make a prefixed DB key from a DB key and a namespace index
         * @param int $ns numerical representation of the namespace
         * @param string $title the DB key form the title
         * @return string the prefixed form of the title
         */
        public static function makeName( $ns, $title ) {
                global $wgContLang;

                $n = $wgContLang->getNsText( $ns );
                return $n == '' ? $title : "$n:$title";
        }

        /**
         * Returns the URL associated with an interwiki prefix
         * @param string $key the interwiki prefix (e.g. "MeatBall")
         * @return the associated URL, containing "$1", which should be
         *      replaced by an article title
         * @static (arguably)
         * @access public
         */
        function getInterwikiLink( $key )  {
                global $wgMemc, $wgInterwikiExpiry;
                global $wgInterwikiCache, $wgContLang;
                $fname = 'Title::getInterwikiLink';

                $key = $wgContLang->lc( $key );

                $k = wfMemcKey( 'interwiki', $key );
                if( array_key_exists( $k, Title::$interwikiCache ) ) {
                        return Title::$interwikiCache[$k]->iw_url;
                }

                if ($wgInterwikiCache) {
                        return Title::getInterwikiCached( $key );
                }

                $s = $wgMemc->get( $k );
                # Ignore old keys with no iw_local
                if( $s && isset( $s->iw_local ) && isset($s->iw_trans)) {
                        Title::$interwikiCache[$k] = $s;
                        return $s->iw_url;
                }

                $dbr = wfGetDB( DB_SLAVE );
                $res = $dbr->select( 'interwiki',
                        array( 'iw_url', 'iw_local', 'iw_trans' ),
                        array( 'iw_prefix' => $key ), $fname );
                if( !$res ) {
                        return '';
                }

                $s = $dbr->fetchObject( $res );
                if( !$s ) {
                        # Cache non-existence: create a blank object and save it to memcached
                        $s = (object)false;
                        $s->iw_url = '';
                        $s->iw_local = 0;
                        $s->iw_trans = 0;
                }
                $wgMemc->set( $k, $s, $wgInterwikiExpiry );
                Title::$interwikiCache[$k] = $s;

                return $s->iw_url;
        }
        
        /**
         * Fetch interwiki prefix data from local cache in constant database
         *
         * More logic is explained in DefaultSettings
         *
         * @return string URL of interwiki site
         * @access public
         */
        function getInterwikiCached( $key ) {
                global $wgInterwikiCache, $wgInterwikiScopes, $wgInterwikiFallbackSite;
                static $db, $site;

                if (!$db)
                        $db=dba_open($wgInterwikiCache,'r','cdb');
                /* Resolve site name */
                if ($wgInterwikiScopes>=3 and !$site) {
                        $site = dba_fetch('__sites:' . wfWikiID(), $db);
                        if ($site=="")
                                $site = $wgInterwikiFallbackSite;
                }
                $value = dba_fetch( wfMemcKey( $key ), $db);
                if ($value=='' and $wgInterwikiScopes>=3) {
                        /* try site-level */
                        $value = dba_fetch("_{$site}:{$key}", $db);
                }
                if ($value=='' and $wgInterwikiScopes>=2) {
                        /* try globals */
                        $value = dba_fetch("__global:{$key}", $db);
                }
                if ($value=='undef')
                        $value='';
                $s = (object)false;
                $s->iw_url = '';
                $s->iw_local = 0;
                $s->iw_trans = 0;
                if ($value!='') {
                        list($local,$url)=explode(' ',$value,2);
                        $s->iw_url=$url;
                        $s->iw_local=(int)$local;
                }
                Title::$interwikiCache[wfMemcKey( 'interwiki', $key )] = $s;
                return $s->iw_url;
        }
        /**
         * Determine whether the object refers to a page within
         * this project.
         *
         * @return bool TRUE if this is an in-project interwiki link
         *      or a wikilink, FALSE otherwise
         * @access public
         */
        function isLocal() {
                if ( $this->mInterwiki != '' ) {
                        # Make sure key is loaded into cache
                        $this->getInterwikiLink( $this->mInterwiki );
                        $k = wfMemcKey( 'interwiki', $this->mInterwiki );
                        return (bool)(Title::$interwikiCache[$k]->iw_local);
                } else {
                        return true;
                }
        }

        /**
         * Determine whether the object refers to a page within
         * this project and is transcludable.
         *
         * @return bool TRUE if this is transcludable
         * @access public
         */
        function isTrans() {
                if ($this->mInterwiki == '')
                        return false;
                # Make sure key is loaded into cache
                $this->getInterwikiLink( $this->mInterwiki );
                $k = wfMemcKey( 'interwiki', $this->mInterwiki );
                return (bool)(Title::$interwikiCache[$k]->iw_trans);
        }

        /**
         * Update the page_touched field for an array of title objects
         * @todo Inefficient unless the IDs are already loaded into the
         *      link cache
         * @param array $titles an array of Title objects to be touched
         * @param string $timestamp the timestamp to use instead of the
         *      default current time
         * @static
         * @access public
         */
        function touchArray( $titles, $timestamp = '' ) {

                if ( count( $titles ) == 0 ) {
                        return;
                }
                $dbw = wfGetDB( DB_MASTER );
                if ( $timestamp == '' ) {
                        $timestamp = $dbw->timestamp();
                }
                /*
                $page = $dbw->tableName( 'page' );
                $sql = "UPDATE $page SET page_touched='{$timestamp}' WHERE page_id IN (";
                $first = true;

                foreach ( $titles as $title ) {
                        if ( $wgUseFileCache ) {
                                $cm = new HTMLFileCache($title);
                                @unlink($cm->fileCacheName());
                        }

                        if ( ! $first ) {
                                $sql .= ',';
                        }
                        $first = false;
                        $sql .= $title->getArticleID();
                }
                $sql .= ')';
                if ( ! $first ) {
                        $dbw->query( $sql, 'Title::touchArray' );
                }
                */
                // hack hack hack -- brion 2005-07-11. this was unfriendly to db.
                // do them in small chunks:
                $fname = 'Title::touchArray';
                foreach( $titles as $title ) {
                        $dbw->update( 'page',
                                array( 'page_touched' => $timestamp ),
                                array(
                                        'page_namespace' => $title->getNamespace(),
                                        'page_title'     => $title->getDBkey() ),
                                $fname );
                }
        }

        /**
         * Escape a text fragment, say from a link, for a URL
         */
        static function escapeFragmentForURL( $fragment ) {
                $fragment = str_replace( ' ', '_', $fragment );
                $fragment = urlencode( Sanitizer::decodeCharReferences( $fragment ) );
                $replaceArray = array(
                        '%3A' => ':',
                        '%' => '.'
                );
                return strtr( $fragment, $replaceArray );
        }

#----------------------------------------------------------------------------
#       Other stuff
#----------------------------------------------------------------------------

        /** Simple accessors */
        /**
         * Get the text form (spaces not underscores) of the main part
         * @return string
         * @access public
         */
        function getText() { return $this->mTextform; }
        /**
         * Get the URL-encoded form of the main part
         * @return string
         * @access public
         */
        function getPartialURL() { return $this->mUrlform; }
        /**
         * Get the main part with underscores
         * @return string
         * @access public
         */
        function getDBkey() { return $this->mDbkeyform; }
        /**
         * Get the namespace index, i.e. one of the NS_xxxx constants
         * @return int
         * @access public
         */
        function getNamespace() { return $this->mNamespace; }
        /**
         * Get the namespace text
         * @return string
         * @access public
         */
        function getNsText() {
                global $wgContLang, $wgCanonicalNamespaceNames;

                if ( '' != $this->mInterwiki ) {
                        // This probably shouldn't even happen. ohh man, oh yuck.
                        // But for interwiki transclusion it sometimes does.
                        // Shit. Shit shit shit.
                        //
                        // Use the canonical namespaces if possible to try to
                        // resolve a foreign namespace.
                        if( isset( $wgCanonicalNamespaceNames[$this->mNamespace] ) ) {
                                return $wgCanonicalNamespaceNames[$this->mNamespace];
                        }
                }
                return $wgContLang->getNsText( $this->mNamespace );
        }
        /**
         * Get the namespace text of the subject (rather than talk) page
         * @return string
         * @access public
         */
        function getSubjectNsText() {
                global $wgContLang;
                return $wgContLang->getNsText( Namespace::getSubject( $this->mNamespace ) );
        }

        /**
         * Get the namespace text of the talk page
         * @return string
         */
        function getTalkNsText() {
                global $wgContLang;
                return( $wgContLang->getNsText( Namespace::getTalk( $this->mNamespace ) ) );
        }
        
        /**
         * Could this title have a corresponding talk page?
         * @return bool
         */
        function canTalk() {
                return( Namespace::canTalk( $this->mNamespace ) );
        }
        
        /**
         * Get the interwiki prefix (or null string)
         * @return string
         * @access public
         */
        function getInterwiki() { return $this->mInterwiki; }
        /**
         * Get the Title fragment (i.e. the bit after the #) in text form
         * @return string
         * @access public
         */
        function getFragment() { return $this->mFragment; }
        /**
         * Get the fragment in URL form, including the "#" character if there is one
         *
         * @return string
         * @access public
         */
        function getFragmentForURL() {
                if ( $this->mFragment == '' ) {
                        return '';
                } else {
                        return '#' . Title::escapeFragmentForURL( $this->mFragment );
                }
        }
        /**
         * Get the default namespace index, for when there is no namespace
         * @return int
         * @access public
         */
        function getDefaultNamespace() { return $this->mDefaultNamespace; }

        /**
         * Get title for search index
         * @return string a stripped-down title string ready for the
         *      search index
         */
        function getIndexTitle() {
                return Title::indexTitle( $this->mNamespace, $this->mTextform );
        }

        /**
         * Get the prefixed database key form
         * @return string the prefixed title, with underscores and
         *      any interwiki and namespace prefixes
         * @access public
         */
        function getPrefixedDBkey() {
                $s = $this->prefix( $this->mDbkeyform );
                $s = str_replace( ' ', '_', $s );
                return $s;
        }

        /**
         * Get the prefixed title with spaces.
         * This is the form usually used for display
         * @return string the prefixed title, with spaces
         * @access public
         */
        function getPrefixedText() {
                if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
                        $s = $this->prefix( $this->mTextform );
                        $s = str_replace( '_', ' ', $s );
                        $this->mPrefixedText = $s;
                }
                return $this->mPrefixedText;
        }

        /**
         * Get the prefixed title with spaces, plus any fragment
         * (part beginning with '#')
         * @return string the prefixed title, with spaces and
         *      the fragment, including '#'
         * @access public
         */
        function getFullText() {
                $text = $this->getPrefixedText();
                if( '' != $this->mFragment ) {
                        $text .= '#' . $this->mFragment;
                }
                return $text;
        }

        /**
         * Get the base name, i.e. the leftmost parts before the /
         * @return string Base name
         */
        function getBaseText() {
                global $wgNamespacesWithSubpages;
                if( isset( $wgNamespacesWithSubpages[ $this->mNamespace ] ) && $wgNamespacesWithSubpages[ $this->mNamespace ] ) {
                        $parts = explode( '/', $this->getText() );
                        # Don't discard the real title if there's no subpage involved
                        if( count( $parts ) > 1 )
                                unset( $parts[ count( $parts ) - 1 ] );
                        return implode( '/', $parts );
                } else {
                        return $this->getText();
                }
        }

        /**
         * Get the lowest-level subpage name, i.e. the rightmost part after /
         * @return string Subpage name
         */
        function getSubpageText() {
                global $wgNamespacesWithSubpages;
                if( isset( $wgNamespacesWithSubpages[ $this->mNamespace ] ) && $wgNamespacesWithSubpages[ $this->mNamespace ] ) {
                        $parts = explode( '/', $this->mTextform );
                        return( $parts[ count( $parts ) - 1 ] );
                } else {
                        return( $this->mTextform );
                }
        }
        
        /**
         * Get a URL-encoded form of the subpage text
         * @return string URL-encoded subpage name
         */
        function getSubpageUrlForm() {
                $text = $this->getSubpageText();
                $text = wfUrlencode( str_replace( ' ', '_', $text ) );
                $text = str_replace( '%28', '(', str_replace( '%29', ')', $text ) ); # Clean up the URL; per below, this might not be safe
                return( $text );
        }

        /**
         * Get a URL-encoded title (not an actual URL) including interwiki
         * @return string the URL-encoded form
         * @access public
         */
        function getPrefixedURL() {
                $s = $this->prefix( $this->mDbkeyform );
                $s = str_replace( ' ', '_', $s );

                $s = wfUrlencode ( $s ) ;

                # Cleaning up URL to make it look nice -- is this safe?
                $s = str_replace( '%28', '(', $s );
                $s = str_replace( '%29', ')', $s );

                return $s;
        }

        /**
         * Get a real URL referring to this title, with interwiki link and
         * fragment
         *
         * @param string $query an optional query string, not used
         *      for interwiki links
         * @param string $variant language variant of url (for sr, zh..)
         * @return string the URL
         * @access public
         */
        function getFullURL( $query = '', $variant = false ) {
                global $wgContLang, $wgServer, $wgRequest;

                if ( '' == $this->mInterwiki ) {
                        $url = $this->getLocalUrl( $query, $variant );

                        // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
                        // Correct fix would be to move the prepending elsewhere.
                        if ($wgRequest->getVal('action') != 'render') {
                                $url = $wgServer . $url;
                        }
                } else {
                        $baseUrl = $this->getInterwikiLink( $this->mInterwiki );

                        $namespace = wfUrlencode( $this->getNsText() );
                        if ( '' != $namespace ) {
                                # Can this actually happen? Interwikis shouldn't be parsed.
                                # Yes! It can in interwiki transclusion. But... it probably shouldn't.
                                $namespace .= ':';
                        }
                        $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
                        $url = wfAppendQuery( $url, $query );
                }

                # Finally, add the fragment.
                $url .= $this->getFragmentForURL();

                wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
                return $url;
        }

        /**
         * Get a URL with no fragment or server name.  If this page is generated
         * with action=render, $wgServer is prepended.
         * @param string $query an optional query string; if not specified,
         *      $wgArticlePath will be used.
         * @param string $variant language variant of url (for sr, zh..)
         * @return string the URL
         * @access public
         */
        function getLocalURL( $query = '', $variant = false ) {
                global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
                global $wgVariantArticlePath, $wgContLang, $wgUser;

                // internal links should point to same variant as current page (only anonymous users)
                if($variant == false && $wgContLang->hasVariants() && !$wgUser->isLoggedIn()){
                        $pref = $wgContLang->getPreferredVariant(false);
                        if($pref != $wgContLang->getCode())
                                $variant = $pref;
                }

                if ( $this->isExternal() ) {
                        $url = $this->getFullURL();
                        if ( $query ) {
                                // This is currently only used for edit section links in the
                                // context of interwiki transclusion. In theory we should
                                // append the query to the end of any existing query string,
                                // but interwiki transclusion is already broken in that case.
                                $url .= "?$query";
                        }
                } else {
                        $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
                        if ( $query == '' ) {
                                if($variant!=false && $wgContLang->hasVariants()){
                                        if($wgVariantArticlePath==false)
                                                $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
                                        else 
                                                $variantArticlePath = $wgVariantArticlePath;
                                        
                                        $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
                                        $url = str_replace( '$1', $dbkey, $url  );
                                        
                                }
                                else 
                                        $url = str_replace( '$1', $dbkey, $wgArticlePath );
                        } else {
                                global $wgActionPaths;
                                $url = false;
                                $matches = array();
                                if( !empty( $wgActionPaths ) &&
                                        preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
                                {
                                        $action = urldecode( $matches[2] );
                                        if( isset( $wgActionPaths[$action] ) ) {
                                                $query = $matches[1];
                                                if( isset( $matches[4] ) ) $query .= $matches[4];
                                                $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
                                                if( $query != '' ) $url .= '?' . $query;
                                        }
                                }
                                if ( $url === false ) {
                                        if ( $query == '-' ) {
                                                $query = '';
                                        }
                                        $url = "{$wgScript}?title={$dbkey}&{$query}";
                                }
                        }
                        
                        // FIXME: this causes breakage in various places when we
                        // actually expected a local URL and end up with dupe prefixes.
                        if ($wgRequest->getVal('action') == 'render') {
                                $url = $wgServer . $url;
                        }
                }
                wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
                return $url;
        }

        /**
         * Get an HTML-escaped version of the URL form, suitable for
         * using in a link, without a server name or fragment
         * @param string $query an optional query string
         * @return string the URL
         * @access public
         */
        function escapeLocalURL( $query = '' ) {
                return htmlspecialchars( $this->getLocalURL( $query ) );
        }

        /**
         * Get an HTML-escaped version of the URL form, suitable for
         * using in a link, including the server name and fragment
         *
         * @return string the URL
         * @param string $query an optional query string
         * @access public
         */
        function escapeFullURL( $query = '' ) {
                return htmlspecialchars( $this->getFullURL( $query ) );
        }

        /**
         * Get the URL form for an internal link.
         * - Used in various Squid-related code, in case we have a different
         * internal hostname for the server from the exposed one.
         *
         * @param string $query an optional query string
         * @param string $variant language variant of url (for sr, zh..)
         * @return string the URL
         * @access public
         */
        function getInternalURL( $query = '', $variant = false ) {
                global $wgInternalServer;
                $url = $wgInternalServer . $this->getLocalURL( $query, $variant );
                wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
                return $url;
        }

        /**
         * Get the edit URL for this Title
         * @return string the URL, or a null string if this is an
         *      interwiki link
         * @access public
         */
        function getEditURL() {
                if ( '' != $this->mInterwiki ) { return ''; }
                $s = $this->getLocalURL( 'action=edit' );

                return $s;
        }

        /**
         * Get the HTML-escaped displayable text form.
         * Used for the title field in <a> tags.
         * @return string the text, including any prefixes
         * @access public
         */
        function getEscapedText() {
                return htmlspecialchars( $this->getPrefixedText() );
        }

        /**
         * Is this Title interwiki?
         * @return boolean
         * @access public
         */
        function isExternal() { return ( '' != $this->mInterwiki ); }

        /**
         * Is this page "semi-protected" - the *only* protection is autoconfirm?
         *
         * @param string Action to check (default: edit)
         * @return bool
         */
        function isSemiProtected( $action = 'edit' ) {
                if( $this->exists() ) {
                        $restrictions = $this->getRestrictions( $action );
                        if( count( $restrictions ) > 0 ) {
                                foreach( $restrictions as $restriction ) {
                                        if( strtolower( $restriction ) != 'autoconfirmed' )
                                                return false;
                                }
                        } else {
                                # Not protected
                                return false;
                        }
                        return true;
                } else {
                        # If it doesn't exist, it can't be protected
                        return false;
                }
        }

        /**
         * Does the title correspond to a protected article?
         * @param string $what the action the page is protected from,
         *      by default checks move and edit
         * @return boolean
         * @access public
         */
        function isProtected( $action = '' ) {
                global $wgRestrictionLevels;

                # Special pages have inherent protection
                if( $this->getNamespace() == NS_SPECIAL )
                        return true;

                # Check regular protection levels                               
                if( $action == 'edit' || $action == '' ) {
                        $r = $this->getRestrictions( 'edit' );
                        foreach( $wgRestrictionLevels as $level ) {
                                if( in_array( $level, $r ) && $level != '' ) {
                                        return( true );
                                }
                        }
                }
                
                if( $action == 'move' || $action == '' ) {
                        $r = $this->getRestrictions( 'move' );
                        foreach( $wgRestrictionLevels as $level ) {
                                if( in_array( $level, $r ) && $level != '' ) {
                                        return( true );
                                }
                        }
                }

                return false;
        }

        /**
         * Is $wgUser is watching this page?
         * @return boolean
         * @access public
         */
        function userIsWatching() {
                global $wgUser;

                if ( is_null( $this->mWatched ) ) {
                        if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn()) {
                                $this->mWatched = false;
                        } else {
                                $this->mWatched = $wgUser->isWatched( $this );
                        }
                }
                return $this->mWatched;
        }

        /**
         * Can $wgUser perform $action on this page?
         * This skips potentially expensive cascading permission checks.
         *
         * Suitable for use for nonessential UI controls in common cases, but
         * _not_ for functional access control.
         *
         * May provide false positives, but should never provide a false negative.
         *
         * @param string $action action that permission needs to be checked for
         * @return boolean
         */
        public function quickUserCan( $action ) {
                return $this->userCan( $action, false );
        }

        /**
         * Can $wgUser perform $action on this page?
         * @param string $action action that permission needs to be checked for
         * @param bool $doExpensiveQueries Set this to false to avoid doing unnecessary queries.
         * @return boolean
         */
        public function userCan( $action, $doExpensiveQueries = true ) {
                $fname = 'Title::userCan';
                wfProfileIn( $fname );

                global $wgUser, $wgNamespaceProtection;

                $result = null;
                wfRunHooks( 'userCan', array( &$this, &$wgUser, $action, &$result ) );
                if ( $result !== null ) {
                        wfProfileOut( $fname );
                        return $result;
                }

                if( NS_SPECIAL == $this->mNamespace ) {
                        wfProfileOut( $fname );
                        return false;
                }
                
                if ( array_key_exists( $this->mNamespace, $wgNamespaceProtection ) ) {
                        $nsProt = $wgNamespaceProtection[ $this->mNamespace ];
                        if ( !is_array($nsProt) ) $nsProt = array($nsProt);
                        foreach( $nsProt as $right ) {
                                if( '' != $right && !$wgUser->isAllowed( $right ) ) {
                                        wfProfileOut( $fname );
                                        return false;
                                }
                        }
                }

                if( $this->mDbkeyform == '_' ) {
                        # FIXME: Is this necessary? Shouldn't be allowed anyway...
                        wfProfileOut( $fname );
                        return false;
                }

                # protect css/js subpages of user pages
                # XXX: this might be better using restrictions
                # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssJsSubpage() from working
                if( $this->isCssJsSubpage()
                        && !$wgUser->isAllowed('editinterface')
                        && !preg_match('/^'.preg_quote($wgUser->getName(), '/').'\//', $this->mTextform) ) {
                        wfProfileOut( $fname );
                        return false;
                }
                
                if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
                        # We /could/ use the protection level on the source page, but it's fairly ugly
                        #  as we have to establish a precedence hierarchy for pages included by multiple
                        #  cascade-protected pages. So just restrict it to people with 'protect' permission,
                        #  as they could remove the protection anyway.
                        list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
                        # Cascading protection depends on more than this page...
                        # Several cascading protected pages may include this page...
                        # Check each cascading level
                        # This is only for protection restrictions, not for all actions
                        if( $cascadingSources > 0 && isset($restrictions[$action]) ) {
                                foreach( $restrictions[$action] as $right ) {
                                        $right = ( $right == 'sysop' ) ? 'protect' : $right;
                                        if( '' != $right && !$wgUser->isAllowed( $right ) ) {
                                                wfProfileOut( $fname );
                                                return false;
                                        }
                                }
                        }
                }
                
                foreach( $this->getRestrictions($action) as $right ) {
                        // Backwards compatibility, rewrite sysop -> protect
                        if ( $right == 'sysop' ) {
                                $right = 'protect';
                        }
                        if( '' != $right && !$wgUser->isAllowed( $right ) ) {
                                wfProfileOut( $fname );
                                return false;
                        }
                }

                if( $action == 'move' &&
                        !( $this->isMovable() && $wgUser->isAllowed( 'move' ) ) ) {
                        wfProfileOut( $fname );
                        return false;
                }

                if( $action == 'create' ) {
                        if( (  $this->isTalkPage() && !$wgUser->isAllowed( 'createtalk' ) ) ||
                                ( !$this->isTalkPage() && !$wgUser->isAllowed( 'createpage' ) ) ) {
                                wfProfileOut( $fname );
                                return false;
                        }
                }

                wfProfileOut( $fname );
                return true;
        }

        /**
         * Can $wgUser edit this page?
         * @return boolean
         * @deprecated use userCan('edit')
         */
        public function userCanEdit( $doExpensiveQueries = true ) {
                return $this->userCan( 'edit', $doExpensiveQueries );
        }

        /**
         * Can $wgUser create this page?
         * @return boolean
         * @deprecated use userCan('create')
         */
        public function userCanCreate( $doExpensiveQueries = true ) {
                return $this->userCan( 'create', $doExpensiveQueries );
        }

        /**
         * Can $wgUser move this page?
         * @return boolean
         * @deprecated use userCan('move')
         */
        public function userCanMove( $doExpensiveQueries = true ) {
                return $this->userCan( 'move', $doExpensiveQueries );
        }

        /**
         * Would anybody with sufficient privileges be able to move this page?
         * Some pages just aren't movable.
         *
         * @return boolean
         * @access public
         */
        function isMovable() {
                return Namespace::isMovable( $this->getNamespace() )
                        && $this->getInterwiki() == '';
        }

        /**
         * Can $wgUser read this page?
         * @return boolean
         * @todo fold these checks into userCan()
         */
        public function userCanRead() {
                global $wgUser;

                $result = null;
                wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
                if ( $result !== null ) {
                        return $result;
                }

                if( $wgUser->isAllowed('read') ) {
                        return true;
                } else {
                        global $wgWhitelistRead;

                        /** 
                         * Always grant access to the login page.
                         * Even anons need to be able to log in.
                        */
                        if( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
                                return true;
                        }

                        /** some pages are explicitly allowed */
                        $name = $this->getPrefixedText();
                        if( $wgWhitelistRead && in_array( $name, $wgWhitelistRead ) ) {
                                return true;
                        }

                        # Compatibility with old settings
                        if( $wgWhitelistRead && $this->getNamespace() == NS_MAIN ) {
                                if( in_array( ':' . $name, $wgWhitelistRead ) ) {
                                        return true;
                                }
                        }
                }
                return false;
        }

        /**
         * Is this a talk page of some sort?
         * @return bool
         * @access public
         */
        function isTalkPage() {
                return Namespace::isTalk( $this->getNamespace() );
        }

        /**
         * Is this a subpage?
         * @return bool
         * @access public
         */
        function isSubpage() {
                global $wgNamespacesWithSubpages;
                
                if( isset( $wgNamespacesWithSubpages[ $this->mNamespace ] ) ) {
                        return ( strpos( $this->getText(), '/' ) !== false && $wgNamespacesWithSubpages[ $this->mNamespace ] == true );
                } else {
                        return false;
                }
        }

        /**
         * Is this a .css or .js subpage of a user page?
         * @return bool
         * @access public
         */
        function isCssJsSubpage() {
                return ( NS_USER == $this->mNamespace and preg_match("/\\/.*\\.(css|js)$/", $this->mTextform ) );
        }
        /**
         * Is this a *valid* .css or .js subpage of a user page?
         * Check that the corresponding skin exists
         */
        function isValidCssJsSubpage() {
                if ( $this->isCssJsSubpage() ) {
                        $skinNames = Skin::getSkinNames();
                        return array_key_exists( $this->getSkinFromCssJsSubpage(), $skinNames );
                } else {
                        return false;
                }
        }
        /**
         * Trim down a .css or .js subpage title to get the corresponding skin name
         */
        function getSkinFromCssJsSubpage() {
                $subpage = explode( '/', $this->mTextform );
                $subpage = $subpage[ count( $subpage ) - 1 ];
                return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
        }
        /**
         * Is this a .css subpage of a user page?
         * @return bool
         * @access public
         */
        function isCssSubpage() {
                return ( NS_USER == $this->mNamespace and preg_match("/\\/.*\\.css$/", $this->mTextform ) );
        }
        /**
         * Is this a .js subpage of a user page?
         * @return bool
         * @access public
         */
        function isJsSubpage() {
                return ( NS_USER == $this->mNamespace and preg_match("/\\/.*\\.js$/", $this->mTextform ) );
        }
        /**
         * Protect css/js subpages of user pages: can $wgUser edit
         * this page?
         *
         * @return boolean
         * @todo XXX: this might be better using restrictions
         * @access public
         */
        function userCanEditCssJsSubpage() {
                global $wgUser;
                return ( $wgUser->isAllowed('editinterface') or preg_match('/^'.preg_quote($wgUser->getName(), '/').'\//', $this->mTextform) );
        }

        /**
         * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
         *
         * @return bool If the page is subject to cascading restrictions.
         * @access public
         */
        function isCascadeProtected() {
                list( $sources, $restrictions ) = $this->getCascadeProtectionSources( false );
                return ( $sources > 0 );
        }

        /**
         * Cascading protection: Get the source of any cascading restrictions on this page.
         *
         * @param $get_pages bool Whether or not to retrieve the actual pages that the restrictions have come from.
         * @return array( mixed title array, restriction array)
         * Array of the Title objects of the pages from which cascading restrictions have come, false for none, or true if such restrictions exist, but $get_pages was not set.
         * The restriction array is an array of each type, each of which contains an array of unique groups
         * @access public
         */
        function getCascadeProtectionSources( $get_pages = true ) {
                global $wgEnableCascadingProtection, $wgRestrictionTypes;

                # Define our dimension of restrictions types
                $pagerestrictions = array();
                foreach( $wgRestrictionTypes as $action )
                        $pagerestrictions[$action] = array();

                if (!$wgEnableCascadingProtection)
                        return array( false, $pagerestrictions );

                if ( isset( $this->mCascadeSources ) && $get_pages ) {
                        return array( $this->mCascadeSources, $this->mCascadingRestrictions );
                } else if ( isset( $this->mHasCascadingRestrictions ) && !$get_pages ) {
                        return array( $this->mHasCascadingRestrictions, $pagerestrictions );
                }

                wfProfileIn( __METHOD__ );

                $dbr = wfGetDb( DB_SLAVE );

                if ( $this->getNamespace() == NS_IMAGE ) {
                        $tables = array ('imagelinks', 'page_restrictions');
                        $where_clauses = array(
                                'il_to' => $this->getDBkey(),
                                'il_from=pr_page',
                                'pr_cascade' => 1 );
                } else {
                        $tables = array ('templatelinks', 'page_restrictions');
                        $where_clauses = array(
                                'tl_namespace' => $this->getNamespace(),
                                'tl_title' => $this->getDBkey(),
                                'tl_from=pr_page',
                                'pr_cascade' => 1 );
                }

                if ( $get_pages ) {
                        $cols = array('pr_page', 'page_namespace', 'page_title', 'pr_expiry', 'pr_type', 'pr_level' );
                        $where_clauses[] = 'page_id=pr_page';
                        $tables[] = 'page';
                } else {
                        $cols = array( 'pr_expiry' );
                }

                $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );

                $sources = $get_pages ? array() : false;
                $now = wfTimestampNow();
                $purgeExpired = false;
                
                while( $row = $dbr->fetchObject( $res ) ) {
                        $expiry = Block::decodeExpiry( $row->pr_expiry );
                        if( $expiry > $now ) {
                                if ($get_pages) {
                                        $page_id = $row->pr_page;
                                        $page_ns = $row->page_namespace;
                                        $page_title = $row->page_title;
                                        $sources[$page_id] = Title::makeTitle($page_ns, $page_title);
                                        # Add groups needed for each restriction type if its not already there
                                        # Make sure this restriction type still exists
                                        if ( isset($pagerestrictions[$row->pr_type]) && !in_array($row->pr_level, $pagerestrictions[$row->pr_type]) ) {
                                                $pagerestrictions[$row->pr_type][]=$row->pr_level;
                                        }
                                } else {
                                        $sources = true;
                                }
                        } else {
                                // Trigger lazy purge of expired restrictions from the db
                                $purgeExpired = true;
                        }
                }
                if( $purgeExpired ) {
                        Title::purgeExpiredRestrictions();
                }

                wfProfileOut( __METHOD__ );

                if ( $get_pages ) {
                        $this->mCascadeSources = $sources;
                        $this->mCascadingRestrictions = $pagerestrictions;
                } else {
                        $this->mHasCascadingRestrictions = $sources;
                }

                return array( $sources, $pagerestrictions );
        }

        function areRestrictionsCascading() {
                if (!$this->mRestrictionsLoaded) {
                        $this->loadRestrictions();
                }

                return $this->mCascadeRestriction;
        }

        /**
         * Loads a string into mRestrictions array
         * @param resource $res restrictions as an SQL result.
         * @access public
         */
        function loadRestrictionsFromRow( $res, $oldFashionedRestrictions = NULL ) {
                $dbr = wfGetDb( DB_SLAVE );

                $this->mRestrictions['edit'] = array();
                $this->mRestrictions['move'] = array();

                # Backwards-compatibility: also load the restrictions from the page record (old format).

                if ( $oldFashionedRestrictions == NULL ) {
                        $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions', array( 'page_id' => $this->getArticleId() ), __METHOD__ );
                }

                if ($oldFashionedRestrictions != '') {

                        foreach( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
                                $temp = explode( '=', trim( $restrict ) );
                                if(count($temp) == 1) {
                                        // old old format should be treated as edit/move restriction
                                        $this->mRestrictions["edit"] = explode( ',', trim( $temp[0] ) );
                                        $this->mRestrictions["move"] = explode( ',', trim( $temp[0] ) );
                                } else {
                                        $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
                                }
                        }

                        $this->mOldRestrictions = true;
                        $this->mCascadeRestriction = false;
                        $this->mRestrictionsExpiry = Block::decodeExpiry('');

                }

                if( $dbr->numRows( $res ) ) {
                        # Current system - load second to make them override.
                        $now = wfTimestampNow();
                        $purgeExpired = false;

                        while ($row = $dbr->fetchObject( $res ) ) {
                                # Cycle through all the restrictions.

                                // This code should be refactored, now that it's being used more generally,
                                // But I don't really see any harm in leaving it in Block for now -werdna
                                $expiry = Block::decodeExpiry( $row->pr_expiry );

                                // Only apply the restrictions if they haven't expired!
                                if ( !$expiry || $expiry > $now ) {
                                        $this->mRestrictionsExpiry = $expiry;
                                        $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );

                                        $this->mCascadeRestriction |= $row->pr_cascade;
                                } else {
                                        // Trigger a lazy purge of expired restrictions
                                        $purgeExpired = true;
                                }
                        }
                
                        if( $purgeExpired ) {
                                Title::purgeExpiredRestrictions();
                        }
                }

                $this->mRestrictionsLoaded = true;
        }

        function loadRestrictions( $oldFashionedRestrictions = NULL ) {
                if( !$this->mRestrictionsLoaded ) {
                        $dbr = wfGetDB( DB_SLAVE );
                
                        $res = $dbr->select( 'page_restrictions', '*',
                                array ( 'pr_page' => $this->getArticleId() ), __METHOD__ );

                        $this->loadRestrictionsFromRow( $res, $oldFashionedRestrictions );
                }
        }

        /** 
         * Purge expired restrictions from the page_restrictions table
         */
        static function purgeExpiredRestrictions() {
                $dbw = wfGetDB( DB_MASTER );
                $dbw->delete( 'page_restrictions',
                        array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
                        __METHOD__ );
        }

        /**
         * Accessor/initialisation for mRestrictions
         *
         * @access public
         * @param string $action action that permission needs to be checked for
         * @return array the array of groups allowed to edit this article
         */
        function getRestrictions( $action ) {
                if( $this->exists() ) {
                        if( !$this->mRestrictionsLoaded ) {
                                $this->loadRestrictions();
                        }
                        return isset( $this->mRestrictions[$action] )
                                        ? $this->mRestrictions[$action]
                                        : array();
                } else {
                        return array();
                }
        }

        /**
         * Is there a version of this page in the deletion archive?
         * @return int the number of archived revisions
         * @access public
         */
        function isDeleted() {
                $fname = 'Title::isDeleted';
                if ( $this->getNamespace() < 0 ) {
                        $n = 0;
                } else {
                        $dbr = wfGetDB( DB_SLAVE );
                        $n = $dbr->selectField( 'archive', 'COUNT(*)', array( 'ar_namespace' => $this->getNamespace(),
                                'ar_title' => $this->getDBkey() ), $fname );
                        if( $this->getNamespace() == NS_IMAGE ) {
                                $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
                                        array( 'fa_name' => $this->getDBkey() ), $fname );
                        }
                }
                return (int)$n;
        }

        /**
         * Get the article ID for this Title from the link cache,
         * adding it if necessary
         * @param int $flags a bit field; may be GAID_FOR_UPDATE to select
         *      for update
         * @return int the ID
         */
        public function getArticleID( $flags = 0 ) {
                $linkCache =& LinkCache::singleton();
                if ( $flags & GAID_FOR_UPDATE ) {
                        $oldUpdate = $linkCache->forUpdate( true );
                        $this->mArticleID = $linkCache->addLinkObj( $this );
                        $linkCache->forUpdate( $oldUpdate );
                } else {
                        if ( -1 == $this->mArticleID ) {
                                $this->mArticleID = $linkCache->addLinkObj( $this );
                        }
                }
                return $this->mArticleID;
        }

        function getLatestRevID() {
                if ($this->mLatestID !== false)
                        return $this->mLatestID;

                $db = wfGetDB(DB_SLAVE);
                return $this->mLatestID = $db->selectField( 'revision',
                        "max(rev_id)",
                        array('rev_page' => $this->getArticleID()),
                        'Title::getLatestRevID' );
        }

        /**
         * This clears some fields in this object, and clears any associated
         * keys in the "bad links" section of the link cache.
         *
         * - This is called from Article::insertNewArticle() to allow
         * loading of the new page_id. It's also called from
         * Article::doDeleteArticle()
         *
         * @param int $newid the new Article ID
         * @access public
         */
        function resetArticleID( $newid ) {
                $linkCache =& LinkCache::singleton();
                $linkCache->clearBadLink( $this->getPrefixedDBkey() );

                if ( 0 == $newid ) { $this->mArticleID = -1; }
                else { $this->mArticleID = $newid; }
                $this->mRestrictionsLoaded = false;
                $this->mRestrictions = array();
        }

        /**
         * Updates page_touched for this page; called from LinksUpdate.php
         * @return bool true if the update succeded
         * @access public
         */
        function invalidateCache() {
                global $wgUseFileCache;

                if ( wfReadOnly() ) {
                        return;
                }

                $dbw = wfGetDB( DB_MASTER );
                $success = $dbw->update( 'page',
                        array( /* SET */
                                'page_touched' => $dbw->timestamp()
                        ), array( /* WHERE */
                                'page_namespace' => $this->getNamespace() ,
                                'page_title' => $this->getDBkey()
                        ), 'Title::invalidateCache'
                );

                if ($wgUseFileCache) {
                        $cache = new HTMLFileCache($this);
                        @unlink($cache->fileCacheName());
                }

                return $success;
        }

        /**
         * Prefix some arbitrary text with the namespace or interwiki prefix
         * of this object
         *
         * @param string $name the text
         * @return string the prefixed text
         * @private
         */
        /* private */ function prefix( $name ) {
                $p = '';
                if ( '' != $this->mInterwiki ) {
                        $p = $this->mInterwiki . ':';
                }
                if ( 0 != $this->mNamespace ) {
                        $p .= $this->getNsText() . ':';
                }
                return $p . $name;
        }

        /**
         * Secure and split - main initialisation function for this object
         *
         * Assumes that mDbkeyform has been set, and is urldecoded
         * and uses underscores, but not otherwise munged.  This function
         * removes illegal characters, splits off the interwiki and
         * namespace prefixes, sets the other forms, and canonicalizes
         * everything.
         * @return bool true on success
         * @private
         */
        /* private */ function secureAndSplit() {
                global $wgContLang, $wgLocalInterwiki, $wgCapitalLinks;

                # Initialisation
                static $rxTc = false;
                if( !$rxTc ) {
                        # % is needed as well
                        $rxTc = '/[^' . Title::legalChars() . ']|%[0-9A-Fa-f]{2}/S';
                }

                $this->mInterwiki = $this->mFragment = '';
                $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
                
                $dbkey = $this->mDbkeyform;

                # Strip Unicode bidi override characters.
                # Sometimes they slip into cut-n-pasted page titles, where the
                # override chars get included in list displays.
                $dbkey = str_replace( "\xE2\x80\x8E", '', $dbkey ); // 200E LEFT-TO-RIGHT MARK
                $dbkey = str_replace( "\xE2\x80\x8F", '', $dbkey ); // 200F RIGHT-TO-LEFT MARK
                
                # Clean up whitespace
                #
                $dbkey = preg_replace( '/[ _]+/', '_', $dbkey );
                $dbkey = trim( $dbkey, '_' );

                if ( '' == $dbkey ) {
                        return false;
                }

                if( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
                        # Contained illegal UTF-8 sequences or forbidden Unicode chars.
                        return false;
                }

                $this->mDbkeyform = $dbkey;

                # Initial colon indicates main namespace rather than specified default
                # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
                if ( ':' == $dbkey{0} ) {
                        $this->mNamespace = NS_MAIN;
                        $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
                }

                # Namespace or interwiki prefix
                $firstPass = true;
                do {
                        $m = array();
                        if ( preg_match( "/^(.+?)_*:_*(.*)$/S", $dbkey, $m ) ) {
                                $p = $m[1];
                                $lowerNs = $wgContLang->lc( $p );
                                if ( $ns = Namespace::getCanonicalIndex( $lowerNs ) ) {
                                        # Canonical namespace
                                        $dbkey = $m[2];
                                        $this->mNamespace = $ns;
                                } elseif ( $ns = $wgContLang->getNsIndex( $lowerNs )) {
                                        # Ordinary namespace
                                        $dbkey = $m[2];
                                        $this->mNamespace = $ns;
                                } elseif( $this->getInterwikiLink( $p ) ) {
                                        if( !$firstPass ) {
                                                # Can't make a local interwiki link to an interwiki link.
                                                # That's just crazy!
                                                return false;
                                        }

                                        # Interwiki link
                                        $dbkey = $m[2];
                                        $this->mInterwiki = $wgContLang->lc( $p );

                                        # Redundant interwiki prefix to the local wiki
                                        if ( 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) ) {
                                                if( $dbkey == '' ) {
                                                        # Can't have an empty self-link
                                                        return false;
                                                }
                                                $this->mInterwiki = '';
                                                $firstPass = false;
                                                # Do another namespace split...
                                                continue;
                                        }

                                        # If there's an initial colon after the interwiki, that also
                                        # resets the default namespace
                                        if ( $dbkey !== '' && $dbkey[0] == ':' ) {
                                                $this->mNamespace = NS_MAIN;
                                                $dbkey = substr( $dbkey, 1 );
                                        }
                                }
                                # If there's no recognized interwiki or namespace,
                                # then let the colon expression be part of the title.
                        }
                        break;
                } while( true );

                # We already know that some pages won't be in the database!
                #
                if ( '' != $this->mInterwiki || NS_SPECIAL == $this->mNamespace ) {
                        $this->mArticleID = 0;
                }
                $fragment = strstr( $dbkey, '#' );
                if ( false !== $fragment ) {
                        $this->setFragment( $fragment );
                        $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
                        # remove whitespace again: prevents "Foo_bar_#"
                        # becoming "Foo_bar_"
                        $dbkey = preg_replace( '/_*$/', '', $dbkey );
                }

                # Reject illegal characters.
                #
                if( preg_match( $rxTc, $dbkey ) ) {
                        return false;
                }

                /**
                 * Pages with "/./" or "/../" appearing in the URLs will
                 * often be unreachable due to the way web browsers deal
                 * with 'relative' URLs. Forbid them explicitly.
                 */
                if ( strpos( $dbkey, '.' ) !== false &&
                     ( $dbkey === '.' || $dbkey === '..' ||
                       strpos( $dbkey, './' ) === 0  ||
                       strpos( $dbkey, '../' ) === 0 ||
                       strpos( $dbkey, '/./' ) !== false ||
                       strpos( $dbkey, '/../' ) !== false ) )
                {
                        return false;
                }
                
                /**
                 * Magic tilde sequences? Nu-uh!
                 */
                if( strpos( $dbkey, '~~~' ) !== false ) {
                        return false;
                }

                /**
                 * Limit the size of titles to 255 bytes.
                 * This is typically the size of the underlying database field.
                 * We make an exception for special pages, which don't need to be stored
                 * in the database, and may edge over 255 bytes due to subpage syntax 
                 * for long titles, e.g. [[Special:Block/Long name]]
                 */
                if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
                  strlen( $dbkey ) > 512 ) 
                {
                        return false;
                }

                /**
                 * Normally, all wiki links are forced to have
                 * an initial capital letter so [[foo]] and [[Foo]]
                 * point to the same place.
                 *
                 * Don't force it for interwikis, since the other
                 * site might be case-sensitive.
                 */
                if( $wgCapitalLinks && $this->mInterwiki == '') {
                        $dbkey = $wgContLang->ucfirst( $dbkey );
                }

                /**
                 * Can't make a link to a namespace alone...
                 * "empty" local links can only be self-links
                 * with a fragment identifier.
                 */
                if( $dbkey == '' &&
                        $this->mInterwiki == '' &&
                        $this->mNamespace != NS_MAIN ) {
                        return false;
                }

                // Any remaining initial :s are illegal.
                if ( $dbkey !== '' && ':' == $dbkey{0} ) {
                        return false;
                }
                
                # Fill fields
                $this->mDbkeyform = $dbkey;
                $this->mUrlform = wfUrlencode( $dbkey );

                $this->mTextform = str_replace( '_', ' ', $dbkey );

                return true;
        }

        /**
         * Set the fragment for this title
         * This is kind of bad, since except for this rarely-used function, Title objects
         * are immutable. The reason this is here is because it's better than setting the 
         * members directly, which is what Linker::formatComment was doing previously.
         *
         * @param string $fragment text
         * @access public
         * @todo clarify whether access is supposed to be public (was marked as "kind of public")
         */
        function setFragment( $fragment ) {
                $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
        }

        /**
         * Get a Title object associated with the talk page of this article
         * @return Title the object for the talk page
         * @access public
         */
        function getTalkPage() {
                return Title::makeTitle( Namespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
        }

        /**
         * Get a title object associated with the subject page of this
         * talk page
         *
         * @return Title the object for the subject page
         * @access public
         */
        function getSubjectPage() {
                return Title::makeTitle( Namespace::getSubject( $this->getNamespace() ), $this->getDBkey() );
        }

        /**
         * Get an array of Title objects linking to this Title
         * Also stores the IDs in the link cache.
         *
         * WARNING: do not use this function on arbitrary user-supplied titles!
         * On heavily-used templates it will max out the memory.
         *
         * @param string $options may be FOR UPDATE
         * @return array the Title objects linking here
         * @access public
         */
        function getLinksTo( $options = '', $table = 'pagelinks', $prefix = 'pl' ) {
                $linkCache =& LinkCache::singleton();

                if ( $options ) {
                        $db = wfGetDB( DB_MASTER );
                } else {
                        $db = wfGetDB( DB_SLAVE );
                }

                $res = $db->select( array( 'page', $table ),
                        array( 'page_namespace', 'page_title', 'page_id' ),
                        array(
                                "{$prefix}_from=page_id",
                                "{$prefix}_namespace" => $this->getNamespace(),
                                "{$prefix}_title"     => $this->getDbKey() ),
                        'Title::getLinksTo',
                        $options );

                $retVal = array();
                if ( $db->numRows( $res ) ) {
                        while ( $row = $db->fetchObject( $res ) ) {
                                if ( $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title ) ) {
                                        $linkCache->addGoodLinkObj( $row->page_id, $titleObj );
                                        $retVal[] = $titleObj;
                                }
                        }
                }
                $db->freeResult( $res );
                return $retVal;
        }

        /**
         * Get an array of Title objects using this Title as a template
         * Also stores the IDs in the link cache.
         *
         * WARNING: do not use this function on arbitrary user-supplied titles!
         * On heavily-used templates it will max out the memory.
         *
         * @param string $options may be FOR UPDATE
         * @return array the Title objects linking here
         * @access public
         */
        function getTemplateLinksTo( $options = '' ) {
                return $this->getLinksTo( $options, 'templatelinks', 'tl' );
        }

        /**
         * Get an array of Title objects referring to non-existent articles linked from this page
         *
         * @param string $options may be FOR UPDATE
         * @return array the Title objects
         * @access public
         */
        function getBrokenLinksFrom( $options = '' ) {
                if ( $options ) {
                        $db = wfGetDB( DB_MASTER );
                } else {
                        $db = wfGetDB( DB_SLAVE );
                }

                $res = $db->safeQuery(
                          "SELECT pl_namespace, pl_title
                             FROM !
                        LEFT JOIN !
                               ON pl_namespace=page_namespace
                              AND pl_title=page_title
                            WHERE pl_from=?
                              AND page_namespace IS NULL
                                  !",
                        $db->tableName( 'pagelinks' ),
                        $db->tableName( 'page' ),
                        $this->getArticleId(),
                        $options );

                $retVal = array();
                if ( $db->numRows( $res ) ) {
                        while ( $row = $db->fetchObject( $res ) ) {
                                $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
                        }
                }
                $db->freeResult( $res );
                return $retVal;
        }


        /**
         * Get a list of URLs to purge from the Squid cache when this
         * page changes
         *
         * @return array the URLs
         * @access public
         */
        function getSquidURLs() {
                global $wgContLang;

                $urls = array(
                        $this->getInternalURL(),
                        $this->getInternalURL( 'action=history' )
                );

                // purge variant urls as well
                if($wgContLang->hasVariants()){
                        $variants = $wgContLang->getVariants();
                        foreach($variants as $vCode){
                                if($vCode==$wgContLang->getCode()) continue; // we don't want default variant
                                $urls[] = $this->getInternalURL('',$vCode);
                        }
                }

                return $urls;
        }

        function purgeSquid() {
                global $wgUseSquid;
                if ( $wgUseSquid ) {
                        $urls = $this->getSquidURLs();
                        $u = new SquidUpdate( $urls );
                        $u->doUpdate();
                }
        }

        /**
         * Move this page without authentication
         * @param Title &$nt the new page Title
         * @access public
         */
        function moveNoAuth( &$nt ) {
                return $this->moveTo( $nt, false );
        }

        /**
         * Check whether a given move operation would be valid.
         * Returns true if ok, or a message key string for an error message
         * if invalid. (Scarrrrry ugly interface this.)
         * @param Title &$nt the new title
         * @param bool $auth indicates whether $wgUser's permissions
         *      should be checked
         * @return mixed true on success, message name on failure
         * @access public
         */
        function isValidMoveOperation( &$nt, $auth = true ) {
                if( !$this or !$nt ) {
                        return 'badtitletext';
                }
                if( $this->equals( $nt ) ) {
                        return 'selfmove';
                }
                if( !$this->isMovable() || !$nt->isMovable() ) {
                        return 'immobile_namespace';
                }

                $oldid = $this->getArticleID();
                $newid = $nt->getArticleID();

                if ( strlen( $nt->getDBkey() ) < 1 ) {
                        return 'articleexists';
                }
                if ( ( '' == $this->getDBkey() ) ||
                         ( !$oldid ) ||
                     ( '' == $nt->getDBkey() ) ) {
                        return 'badarticleerror';
                }

                if ( $auth && (
                                !$this->userCan( 'edit' ) || !$nt->userCan( 'edit' ) ||
                                !$this->userCan( 'move' ) || !$nt->userCan( 'move' ) ) ) {
                        return 'protectedpage';
                }

                # The move is allowed only if (1) the target doesn't exist, or
                # (2) the target is a redirect to the source, and has no history
                # (so we can undo bad moves right after they're done).

                if ( 0 != $newid ) { # Target exists; check for validity
                        if ( ! $this->isValidMoveTarget( $nt ) ) {
                                return 'articleexists';
                        }
                }
                return true;
        }

        /**
         * Move a title to a new location
         * @param Title &$nt the new title
         * @param bool $auth indicates whether $wgUser's permissions
         *      should be checked
         * @return mixed true on success, message name on failure
         * @access public
         */
        function moveTo( &$nt, $auth = true, $reason = '' ) {
                $err = $this->isValidMoveOperation( $nt, $auth );
                if( is_string( $err ) ) {
                        return $err;
                }

                $pageid = $this->getArticleID();
                if( $nt->exists() ) {
                        $this->moveOverExistingRedirect( $nt, $reason );
                        $pageCountChange = 0;
                } else { # Target didn't exist, do normal move.
                        $this->moveToNewTitle( $nt, $reason );
                        $pageCountChange = 1;
                }
                $redirid = $this->getArticleID();

                # Fixing category links (those without piped 'alternate' names) to be sorted under the new title
                $dbw = wfGetDB( DB_MASTER );
                $categorylinks = $dbw->tableName( 'categorylinks' );
                $sql = "UPDATE $categorylinks SET cl_sortkey=" . $dbw->addQuotes( $nt->getPrefixedText() ) .
                        " WHERE cl_from=" . $dbw->addQuotes( $pageid ) .
                        " AND cl_sortkey=" . $dbw->addQuotes( $this->getPrefixedText() );
                $dbw->query( $sql, 'SpecialMovepage::doSubmit' );

                # Update watchlists

                $oldnamespace = $this->getNamespace() & ~1;
                $newnamespace = $nt->getNamespace() & ~1;
                $oldtitle = $this->getDBkey();
                $newtitle = $nt->getDBkey();

                if( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
                        WatchedItem::duplicateEntries( $this, $nt );
                }

                # Update search engine
                $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
                $u->doUpdate();
                $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
                $u->doUpdate();

                # Update site_stats
                if( $this->isContentPage() && !$nt->isContentPage() ) {
                        # No longer a content page
                        # Not viewed, edited, removing
                        $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
                } elseif( !$this->isContentPage() && $nt->isContentPage() ) {
                        # Now a content page
                        # Not viewed, edited, adding
                        $u = new SiteStatsUpdate( 0, 1, +1, $pageCountChange );
                } elseif( $pageCountChange ) {
                        # Redirect added
                        $u = new SiteStatsUpdate( 0, 0, 0, 1 );
                } else {
                        # Nothing special
                        $u = false;
                }
                if( $u )
                        $u->doUpdate();
                
                global $wgUser;
                wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
                return true;
        }

        /**
         * Move page to a title which is at present a redirect to the
         * source page
         *
         * @param Title &$nt the page to move to, which should currently
         *      be a redirect
         * @private
         */
        function moveOverExistingRedirect( &$nt, $reason = '' ) {
                global $wgUseSquid;
                $fname = 'Title::moveOverExistingRedirect';
                $comment = wfMsgForContent( '1movedto2_redir', $this->getPrefixedText(), $nt->getPrefixedText() );

                if ( $reason ) {
                        $comment .= ": $reason";
                }

                $now = wfTimestampNow();
                $newid = $nt->getArticleID();
                $oldid = $this->getArticleID();
                $dbw = wfGetDB( DB_MASTER );
                $linkCache =& LinkCache::singleton();

                # Delete the old redirect. We don't save it to history since
                # by definition if we've got here it's rather uninteresting.
                # We have to remove it so that the next step doesn't trigger
                # a conflict on the unique namespace+title index...
                $dbw->delete( 'page', array( 'page_id' => $newid ), $fname );

                # Save a null revision in the page's history notifying of the move
                $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
                $nullRevId = $nullRevision->insertOn( $dbw );

                # Change the name of the target page:
                $dbw->update( 'page',
                        /* SET */ array(
                                'page_touched'   => $dbw->timestamp($now),
                                'page_namespace' => $nt->getNamespace(),
                                'page_title'     => $nt->getDBkey(),
                                'page_latest'    => $nullRevId,
                        ),
                        /* WHERE */ array( 'page_id' => $oldid ),
                        $fname
                );
                $linkCache->clearLink( $nt->getPrefixedDBkey() );

                # Recreate the redirect, this time in the other direction.
                $mwRedir = MagicWord::get( 'redirect' );
                $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
                $redirectArticle = new Article( $this );
                $newid = $redirectArticle->insertOn( $dbw );
                $redirectRevision = new Revision( array(
                        'page'    => $newid,
                        'comment' => $comment,
                        'text'    => $redirectText ) );
                $redirectRevision->insertOn( $dbw );
                $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
                $linkCache->clearLink( $this->getPrefixedDBkey() );

                # Log the move
                $log = new LogPage( 'move' );
                $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText() ) );

                # Now, we record the link from the redirect to the new title.
                # It should have no other outgoing links...
                $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), $fname );
                $dbw->insert( 'pagelinks',
                        array(
                                'pl_from'      => $newid,
                                'pl_namespace' => $nt->getNamespace(),
                                'pl_title'     => $nt->getDbKey() ),
                        $fname );

                # Purge squid
                if ( $wgUseSquid ) {
                        $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
                        $u = new SquidUpdate( $urls );
                        $u->doUpdate();
                }
        }

        /**
         * Move page to non-existing title.
         * @param Title &$nt the new Title
         * @private
         */
        function moveToNewTitle( &$nt, $reason = '' ) {
                global $wgUseSquid;
                $fname = 'MovePageForm::moveToNewTitle';
                $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
                if ( $reason ) {
                        $comment .= ": $reason";
                }

                $newid = $nt->getArticleID();
                $oldid = $this->getArticleID();
                $dbw = wfGetDB( DB_MASTER );
                $now = $dbw->timestamp();
                $linkCache =& LinkCache::singleton();

                # Save a null revision in the page's history notifying of the move
                $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
                $nullRevId = $nullRevision->insertOn( $dbw );

                # Rename cur entry
                $dbw->update( 'page',
                        /* SET */ array(
                                'page_touched'   => $now,
                                'page_namespace' => $nt->getNamespace(),
                                'page_title'     => $nt->getDBkey(),
                                'page_latest'    => $nullRevId,
                        ),
                        /* WHERE */ array( 'page_id' => $oldid ),
                        $fname
                );

                $linkCache->clearLink( $nt->getPrefixedDBkey() );

                # Insert redirect
                $mwRedir = MagicWord::get( 'redirect' );
                $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
                $redirectArticle = new Article( $this );
                $newid = $redirectArticle->insertOn( $dbw );
                $redirectRevision = new Revision( array(
                        'page'    => $newid,
                        'comment' => $comment,
                        'text'    => $redirectText ) );
                $redirectRevision->insertOn( $dbw );
                $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
                $linkCache->clearLink( $this->getPrefixedDBkey() );

                # Log the move
                $log = new LogPage( 'move' );
                $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText()) );

                # Purge caches as per article creation
                Article::onArticleCreate( $nt );

                # Record the just-created redirect's linking to the page
                $dbw->insert( 'pagelinks',
                        array(
                                'pl_from'      => $newid,
                                'pl_namespace' => $nt->getNamespace(),
                                'pl_title'     => $nt->getDBkey() ),
                        $fname );

                # Purge old title from squid
                # The new title, and links to the new title, are purged in Article::onArticleCreate()
                $this->purgeSquid();
        }

        /**
         * Checks if $this can be moved to a given Title
         * - Selects for update, so don't call it unless you mean business
         *
         * @param Title &$nt the new title to check
         * @access public
         */
        function isValidMoveTarget( $nt ) {

                $fname = 'Title::isValidMoveTarget';
                $dbw = wfGetDB( DB_MASTER );

                # Is it a redirect?
                $id  = $nt->getArticleID();
                $obj = $dbw->selectRow( array( 'page', 'revision', 'text'),
                        array( 'page_is_redirect','old_text','old_flags' ),
                        array( 'page_id' => $id, 'page_latest=rev_id', 'rev_text_id=old_id' ),
                        $fname, 'FOR UPDATE' );

                if ( !$obj || 0 == $obj->page_is_redirect ) {
                        # Not a redirect
                        wfDebug( __METHOD__ . ": not a redirect\n" );
                        return false;
                }
                $text = Revision::getRevisionText( $obj );

                # Does the redirect point to the source?
                # Or is it a broken self-redirect, usually caused by namespace collisions?
                $m = array();
                if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
                        $redirTitle = Title::newFromText( $m[1] );
                        if( !is_object( $redirTitle ) ||
                                ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
                                $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
                                wfDebug( __METHOD__ . ": redirect points to other page\n" );
                                return false;
                        }
                } else {
                        # Fail safe
                        wfDebug( __METHOD__ . ": failsafe\n" );
                        return false;
                }

                # Does the article have a history?
                $row = $dbw->selectRow( array( 'page', 'revision'),
                        array( 'rev_id' ),
                        array( 'page_namespace' => $nt->getNamespace(),
                                'page_title' => $nt->getDBkey(),
                                'page_id=rev_page AND page_latest != rev_id'
                        ), $fname, 'FOR UPDATE'
                );

                # Return true if there was no history
                return $row === false;
        }

        /**
         * Get categories to which this Title belongs and return an array of
         * categories' names.
         *
         * @return array an array of parents in the form:
         *      $parent => $currentarticle
         * @access public
         */
        function getParentCategories() {
                global $wgContLang;

                $titlekey = $this->getArticleId();
                $dbr = wfGetDB( DB_SLAVE );
                $categorylinks = $dbr->tableName( 'categorylinks' );

                # NEW SQL
                $sql = "SELECT * FROM $categorylinks"
                     ." WHERE cl_from='$titlekey'"
                         ." AND cl_from <> '0'"
                         ." ORDER BY cl_sortkey";

                $res = $dbr->query ( $sql ) ;

                if($dbr->numRows($res) > 0) {
                        while ( $x = $dbr->fetchObject ( $res ) )
                                //$data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$x->cl_to);
                                $data[$wgContLang->getNSText ( NS_CATEGORY ).':'.$x->cl_to] = $this->getFullText();
                        $dbr->freeResult ( $res ) ;
                } else {
                        $data = '';
                }
                return $data;
        }

        /**
         * Get a tree of parent categories
         * @param array $children an array with the children in the keys, to check for circular refs
         * @return array
         * @access public
         */
        function getParentCategoryTree( $children = array() ) {
                $parents = $this->getParentCategories();

                if($parents != '') {
                        foreach($parents as $parent => $current) {
                                if ( array_key_exists( $parent, $children ) ) {
                                        # Circular reference
                                        $stack[$parent] = array();
                                } else {
                                        $nt = Title::newFromText($parent);
                                        if ( $nt ) {
                                                $stack[$parent] = $nt->getParentCategoryTree( $children + array($parent => 1) );
                                        }
                                }
                        }
                        return $stack;
                } else {
                        return array();
                }
        }


        /**
         * Get an associative array for selecting this title from
         * the "page" table
         *
         * @return array
         * @access public
         */
        function pageCond() {
                return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
        }

        /**
         * Get the revision ID of the previous revision
         *
         * @param integer $revision  Revision ID. Get the revision that was before this one.
         * @return integer $oldrevision|false
         */
        function getPreviousRevisionID( $revision ) {
                $dbr = wfGetDB( DB_SLAVE );
                return $dbr->selectField( 'revision', 'rev_id',
                        'rev_page=' . intval( $this->getArticleId() ) .
                        ' AND rev_id<' . intval( $revision ) . ' ORDER BY rev_id DESC' );
        }

        /**
         * Get the revision ID of the next revision
         *
         * @param integer $revision  Revision ID. Get the revision that was after this one.
         * @return integer $oldrevision|false
         */
        function getNextRevisionID( $revision ) {
                $dbr = wfGetDB( DB_SLAVE );
                return $dbr->selectField( 'revision', 'rev_id',
                        'rev_page=' . intval( $this->getArticleId() ) .
                        ' AND rev_id>' . intval( $revision ) . ' ORDER BY rev_id' );
        }

        /**
         * Get the number of revisions between the given revision IDs.
         *
         * @param integer $old  Revision ID.
         * @param integer $new  Revision ID.
         * @return integer  Number of revisions between these IDs.
         */
        function countRevisionsBetween( $old, $new ) {
                $dbr = wfGetDB( DB_SLAVE );
                return $dbr->selectField( 'revision', 'count(*)',
                        'rev_page = ' . intval( $this->getArticleId() ) .
                        ' AND rev_id > ' . intval( $old ) .
                        ' AND rev_id < ' . intval( $new ) );
        }

        /**
         * Compare with another title.
         *
         * @param Title $title
         * @return bool
         */
        function equals( $title ) {
                // Note: === is necessary for proper matching of number-like titles.
                return $this->getInterwiki() === $title->getInterwiki()
                        && $this->getNamespace() == $title->getNamespace()
                        && $this->getDbkey() === $title->getDbkey();
        }

        /**
         * Check if page exists
         * @return bool
         */
        function exists() {
                return $this->getArticleId() != 0;
        }

        /**
         * Should a link should be displayed as a known link, just based on its title?
         *
         * Currently, a self-link with a fragment and special pages are in
         * this category. Special pages never exist in the database.
         */
        function isAlwaysKnown() {
                return  $this->isExternal() || ( 0 == $this->mNamespace && "" == $this->mDbkeyform )
                  || NS_SPECIAL == $this->mNamespace;
        }

        /**
         * Update page_touched timestamps and send squid purge messages for
         * pages linking to this title. May be sent to the job queue depending 
         * on the number of links. Typically called on create and delete.
         */
        function touchLinks() {
                $u = new HTMLCacheUpdate( $this, 'pagelinks' );
                $u->doUpdate();

                if ( $this->getNamespace() == NS_CATEGORY ) {
                        $u = new HTMLCacheUpdate( $this, 'categorylinks' );
                        $u->doUpdate();
                }
        }

        /**
         * Get the last touched timestamp
         */
        function getTouched() {
                $dbr = wfGetDB( DB_SLAVE );
                $touched = $dbr->selectField( 'page', 'page_touched',
                        array( 
                                'page_namespace' => $this->getNamespace(),
                                'page_title' => $this->getDBkey()
                        ), __METHOD__
                );
                return $touched;
        }

        /**
         * Get a cached value from a global cache that is invalidated when this page changes
         * @param string $key the key
         * @param callback $callback A callback function which generates the value on cache miss
         *
         * @deprecated use DependencyWrapper
         */
        function getRelatedCache( $memc, $key, $expiry, $callback, $params = array() ) {
                return DependencyWrapper::getValueFromCache( $memc, $key, $expiry, $callback, 
                        $params, new TitleDependency( $this ) );
        }

        function trackbackURL() {
                global $wgTitle, $wgScriptPath, $wgServer;

                return "$wgServer$wgScriptPath/trackback.php?article="
                        . htmlspecialchars(urlencode($wgTitle->getPrefixedDBkey()));
        }

        function trackbackRDF() {
                $url = htmlspecialchars($this->getFullURL());
                $title = htmlspecialchars($this->getText());
                $tburl = $this->trackbackURL();

                return "
<rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
         xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
         xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
<rdf:Description
   rdf:about=\"$url\"
   dc:identifier=\"$url\"
   dc:title=\"$title\"
   trackback:ping=\"$tburl\" />
</rdf:RDF>";
        }

        /**
         * Generate strings used for xml 'id' names in monobook tabs
         * @return string
         */
        function getNamespaceKey() {
                global $wgContLang;
                switch ($this->getNamespace()) {
                        case NS_MAIN:
                        case NS_TALK:
                                return 'nstab-main';
                        case NS_USER:
                        case NS_USER_TALK:
                                return 'nstab-user';
                        case NS_MEDIA:
                                return 'nstab-media';
                        case NS_SPECIAL:
                                return 'nstab-special';
                        case NS_PROJECT:
                        case NS_PROJECT_TALK:
                                return 'nstab-project';
                        case NS_IMAGE:
                        case NS_IMAGE_TALK:
                                return 'nstab-image';
                        case NS_MEDIAWIKI:
                        case NS_MEDIAWIKI_TALK:
                                return 'nstab-mediawiki';
                        case NS_TEMPLATE:
                        case NS_TEMPLATE_TALK:
                                return 'nstab-template';
                        case NS_HELP:
                        case NS_HELP_TALK:
                                return 'nstab-help';
                        case NS_CATEGORY:
                        case NS_CATEGORY_TALK:
                                return 'nstab-category';
                        default:
                                return 'nstab-' . $wgContLang->lc( $this->getSubjectNsText() );
                }
        }

        /**
         * Returns true if this title resolves to the named special page
         * @param string $name The special page name
         * @access public
         */
        function isSpecial( $name ) {
                if ( $this->getNamespace() == NS_SPECIAL ) {
                        list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
                        if ( $name == $thisName ) {
                                return true;
                        }
                }
                return false;
        }

        /**
         * If the Title refers to a special page alias which is not the local default, 
         * returns a new Title which points to the local default. Otherwise, returns $this.
         */
        function fixSpecialName() {
                if ( $this->getNamespace() == NS_SPECIAL ) {
                        $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
                        if ( $canonicalName ) {
                                $localName = SpecialPage::getLocalNameFor( $canonicalName );
                                if ( $localName != $this->mDbkeyform ) {
                                        return Title::makeTitle( NS_SPECIAL, $localName );
                                }
                        }
                }
                return $this;
        }
        
        /**
         * Is this Title in a namespace which contains content?
         * In other words, is this a content page, for the purposes of calculating
         * statistics, etc?
         *
         * @return bool
         */
        public function isContentPage() {
                return Namespace::isContent( $this->getNamespace() );
        }
        
}

?>