includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  * @file
   5  */
   6
   7 /**
   8  * @todo:  determine if it is really necessary to load this.  Appears to be left over from pre-autoloader versions, and
   9  *   is only really needed to provide access to constant UTF8_REPLACEMENT, which actually resides in UtfNormalDefines.php
  10  *   and is loaded by UtfNormalUtil.php, which is loaded by UtfNormal.php.
  11  */
  12 if ( !class_exists( 'UtfNormal' ) ) {
  13         require_once( dirname( __FILE__ ) . '/normal/UtfNormal.php' );
  14 }
  15
  16 define ( 'GAID_FOR_UPDATE', 1 );
  17
  18 /**
  19  * Represents a title within MediaWiki.
  20  * Optionally may contain an interwiki designation or namespace.
  21  * @note This class can fetch various kinds of data from the database;
  22  *       however, it does so inefficiently.
  23  *
  24  * @internal documentation reviewed 15 Mar 2010
  25  */
  26 class Title {
  27         /** @name Static cache variables */
  28         // @{
  29         static private $titleCache = array();
  30         static private $interwikiCache = array();
  31         // @}
  32
  33         /**
  34          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  35          * commonly used titles. On a batch operation this can become a memory leak
  36          * if not bounded. After hitting this many titles reset the cache.
  37          */
  38         const CACHE_MAX = 1000;
  39
  40
  41         /**
  42          * @name Private member variables
  43          * Please use the accessor functions instead.
  44          * @private
  45          */
  46         // @{
  47
  48         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  49         var $mUrlform = '';               // /< URL-encoded form of the main part
  50         var $mDbkeyform = '';             // /< Main part with underscores
  51         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  52         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  53         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  54         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  55         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  56         var $mLatestID = false;           // /< ID of most recent revision
  57         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  58         var $mOldRestrictions = false;
  59         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  60         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  61         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  62         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  63         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  64         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  65         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  66         var $mTitleProtection;            ///< Cached value of getTitleProtection
  67         # Don't change the following default, NS_MAIN is hardcoded in several
  68         # places.  See bug 696.
  69         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  70                                           # Zero except in {{transclusion}} tags
  71         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  72         var $mLength = -1;                // /< The page length, 0 for special pages
  73         var $mRedirect = null;            // /< Is the article at this title a redirect?
  74         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  75         var $mBacklinkCache = null;       // /< Cache of links to this title
  76         // @}
  77
  78
  79         /**
  80          * Constructor
  81          * @private
  82          */
  83         /* private */ function __construct() { }
  84
  85         /**
  86          * Create a new Title from a prefixed DB key
  87          *
  88          * @param $key \type{\string} The database key, which has underscores
  89          *      instead of spaces, possibly including namespace and
  90          *      interwiki prefixes
  91          * @return \type{Title} the new object, or NULL on an error
  92          */
  93         public static function newFromDBkey( $key ) {
  94                 $t = new Title();
  95                 $t->mDbkeyform = $key;
  96                 if ( $t->secureAndSplit() )
  97                         return $t;
  98                 else
  99                         return null;
 100         }
 101
 102         /**
 103          * Create a new Title from text, such as what one would find in a link. De-
 104          * codes any HTML entities in the text.
 105          *
 106          * @param $text string  The link text; spaces, prefixes, and an
 107          *   initial ':' indicating the main namespace are accepted.
 108          * @param $defaultNamespace int The namespace to use if none is speci-
 109          *   fied by a prefix.  If you want to force a specific namespace even if
 110          *   $text might begin with a namespace prefix, use makeTitle() or
 111          *   makeTitleSafe().
 112          * @return Title  The new object, or null on an error.
 113          */
 114         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 115                 if ( is_object( $text ) ) {
 116                         throw new MWException( 'Title::newFromText given an object' );
 117                 }
 118
 119                 /**
 120                  * Wiki pages often contain multiple links to the same page.
 121                  * Title normalization and parsing can become expensive on
 122                  * pages with many links, so we can save a little time by
 123                  * caching them.
 124                  *
 125                  * In theory these are value objects and won't get changed...
 126                  */
 127                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 128                         return Title::$titleCache[$text];
 129                 }
 130
 131                 /**
 132                  * Convert things like &eacute; &#257; or &#x3017; into normalized(bug 14952) text
 133                  */
 134                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 135
 136                 $t = new Title();
 137                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 138                 $t->mDefaultNamespace = $defaultNamespace;
 139
 140                 static $cachedcount = 0 ;
 141                 if ( $t->secureAndSplit() ) {
 142                         if ( $defaultNamespace == NS_MAIN ) {
 143                                 if ( $cachedcount >= self::CACHE_MAX ) {
 144                                         # Avoid memory leaks on mass operations...
 145                                         Title::$titleCache = array();
 146                                         $cachedcount = 0;
 147                                 }
 148                                 $cachedcount++;
 149                                 Title::$titleCache[$text] =& $t;
 150                         }
 151                         return $t;
 152                 } else {
 153                         $ret = null;
 154                         return $ret;
 155                 }
 156         }
 157
 158         /**
 159          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 160          *
 161          * Example of wrong and broken code:
 162          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 163          *
 164          * Example of right code:
 165          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 166          *
 167          * Create a new Title from URL-encoded text. Ensures that
 168          * the given title's length does not exceed the maximum.
 169          *
 170          * @param $url \type{\string} the title, as might be taken from a URL
 171          * @return \type{Title} the new object, or NULL on an error
 172          */
 173         public static function newFromURL( $url ) {
 174                 global $wgLegalTitleChars;
 175                 $t = new Title();
 176
 177                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 178                 # but some URLs used it as a space replacement and they still come
 179                 # from some external search tools.
 180                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 181                         $url = str_replace( '+', ' ', $url );
 182                 }
 183
 184                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 185                 if ( $t->secureAndSplit() ) {
 186                         return $t;
 187                 } else {
 188                         return null;
 189                 }
 190         }
 191
 192         /**
 193          * Create a new Title from an article ID
 194          *
 195          * @param $id \type{\int} the page_id corresponding to the Title to create
 196          * @param $flags \type{\int} use GAID_FOR_UPDATE to use master
 197          * @return \type{Title} the new object, or NULL on an error
 198          */
 199         public static function newFromID( $id, $flags = 0 ) {
 200                 $db = ( $flags & GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 201                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 202                 if ( $row !== false ) {
 203                         $title = Title::newFromRow( $row );
 204                 } else {
 205                         $title = null;
 206                 }
 207                 return $title;
 208         }
 209
 210         /**
 211          * Make an array of titles from an array of IDs
 212          *
 213          * @param $ids \type{\arrayof{\int}} Array of IDs
 214          * @return \type{\arrayof{Title}} Array of Titles
 215          */
 216         public static function newFromIDs( $ids ) {
 217                 if ( !count( $ids ) ) {
 218                         return array();
 219                 }
 220                 $dbr = wfGetDB( DB_SLAVE );
 221
 222                 $res = $dbr->select(
 223                         'page',
 224                         array(
 225                                 'page_namespace', 'page_title', 'page_id',
 226                                 'page_len', 'page_is_redirect', 'page_latest',
 227                         ),
 228                         array( 'page_id' => $ids ),
 229                         __METHOD__
 230                 );
 231
 232                 $titles = array();
 233                 foreach ( $res as $row ) {
 234                         $titles[] = Title::newFromRow( $row );
 235                 }
 236                 return $titles;
 237         }
 238
 239         /**
 240          * Make a Title object from a DB row
 241          *
 242          * @param $row \type{Row} (needs at least page_title,page_namespace)
 243          * @return \type{Title} corresponding Title
 244          */
 245         public static function newFromRow( $row ) {
 246                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 247
 248                 $t->mArticleID = isset( $row->page_id ) ? intval( $row->page_id ) : -1;
 249                 $t->mLength = isset( $row->page_len ) ? intval( $row->page_len ) : -1;
 250                 $t->mRedirect = isset( $row->page_is_redirect ) ? (bool)$row->page_is_redirect : null;
 251                 $t->mLatestID = isset( $row->page_latest ) ? intval( $row->page_latest ) : false;
 252
 253                 return $t;
 254         }
 255
 256         /**
 257          * Create a new Title from a namespace index and a DB key.
 258          * It's assumed that $ns and $title are *valid*, for instance when
 259          * they came directly from the database or a special page name.
 260          * For convenience, spaces are converted to underscores so that
 261          * eg user_text fields can be used directly.
 262          *
 263          * @param $ns \type{\int} the namespace of the article
 264          * @param $title \type{\string} the unprefixed database key form
 265          * @param $fragment \type{\string} The link fragment (after the "#")
 266          * @param $interwiki \type{\string} The interwiki prefix
 267          * @return \type{Title} the new object
 268          */
 269         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 270                 $t = new Title();
 271                 $t->mInterwiki = $interwiki;
 272                 $t->mFragment = $fragment;
 273                 $t->mNamespace = $ns = intval( $ns );
 274                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 275                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 276                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 277                 $t->mTextform = str_replace( '_', ' ', $title );
 278                 return $t;
 279         }
 280
 281         /**
 282          * Create a new Title from a namespace index and a DB key.
 283          * The parameters will be checked for validity, which is a bit slower
 284          * than makeTitle() but safer for user-provided data.
 285          *
 286          * @param $ns \type{\int} the namespace of the article
 287          * @param $title \type{\string} the database key form
 288          * @param $fragment \type{\string} The link fragment (after the "#")
 289          * @param $interwiki \type{\string} The interwiki prefix
 290          * @return \type{Title} the new object, or NULL on an error
 291          */
 292         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 293                 $t = new Title();
 294                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 295                 if ( $t->secureAndSplit() ) {
 296                         return $t;
 297                 } else {
 298                         return null;
 299                 }
 300         }
 301
 302         /**
 303          * Create a new Title for the Main Page
 304          *
 305          * @return \type{Title} the new object
 306          */
 307         public static function newMainPage() {
 308                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 309                 // Don't give fatal errors if the message is broken
 310                 if ( !$title ) {
 311                         $title = Title::newFromText( 'Main Page' );
 312                 }
 313                 return $title;
 314         }
 315
 316         /**
 317          * Extract a redirect destination from a string and return the
 318          * Title, or null if the text doesn't contain a valid redirect
 319          * This will only return the very next target, useful for
 320          * the redirect table and other checks that don't need full recursion
 321          *
 322          * @param $text \type{\string} Text with possible redirect
 323          * @return \type{Title} The corresponding Title
 324          */
 325         public static function newFromRedirect( $text ) {
 326                 return self::newFromRedirectInternal( $text );
 327         }
 328
 329         /**
 330          * Extract a redirect destination from a string and return the
 331          * Title, or null if the text doesn't contain a valid redirect
 332          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 333          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 334          *
 335          * @param $text \type{\string} Text with possible redirect
 336          * @return \type{Title} The corresponding Title
 337          */
 338         public static function newFromRedirectRecurse( $text ) {
 339                 $titles = self::newFromRedirectArray( $text );
 340                 return $titles ? array_pop( $titles ) : null;
 341         }
 342
 343         /**
 344          * Extract a redirect destination from a string and return an
 345          * array of Titles, or null if the text doesn't contain a valid redirect
 346          * The last element in the array is the final destination after all redirects
 347          * have been resolved (up to $wgMaxRedirects times)
 348          *
 349          * @param $text \type{\string} Text with possible redirect
 350          * @return \type{\array} Array of Titles, with the destination last
 351          */
 352         public static function newFromRedirectArray( $text ) {
 353                 global $wgMaxRedirects;
 354                 // are redirects disabled?
 355                 if ( $wgMaxRedirects < 1 )
 356                         return null;
 357                 $title = self::newFromRedirectInternal( $text );
 358                 if ( is_null( $title ) )
 359                         return null;
 360                 // recursive check to follow double redirects
 361                 $recurse = $wgMaxRedirects;
 362                 $titles = array( $title );
 363                 while ( --$recurse > 0 ) {
 364                         if ( $title->isRedirect() ) {
 365                                 $article = new Article( $title, 0 );
 366                                 $newtitle = $article->getRedirectTarget();
 367                         } else {
 368                                 break;
 369                         }
 370                         // Redirects to some special pages are not permitted
 371                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 372                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 373                                 $title = $newtitle;
 374                                 $titles[] = $newtitle;
 375                         } else {
 376                                 break;
 377                         }
 378                 }
 379                 return $titles;
 380         }
 381
 382         /**
 383          * Really extract the redirect destination
 384          * Do not call this function directly, use one of the newFromRedirect* functions above
 385          *
 386          * @param $text \type{\string} Text with possible redirect
 387          * @return \type{Title} The corresponding Title
 388          */
 389         protected static function newFromRedirectInternal( $text ) {
 390                 $redir = MagicWord::get( 'redirect' );
 391                 $text = trim( $text );
 392                 if ( $redir->matchStartAndRemove( $text ) ) {
 393                         // Extract the first link and see if it's usable
 394                         // Ensure that it really does come directly after #REDIRECT
 395                         // Some older redirects included a colon, so don't freak about that!
 396                         $m = array();
 397                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 398                                 // Strip preceding colon used to "escape" categories, etc.
 399                                 // and URL-decode links
 400                                 if ( strpos( $m[1], '%' ) !== false ) {
 401                                         // Match behavior of inline link parsing here;
 402                                         // don't interpret + as " " most of the time!
 403                                         // It might be safe to just use rawurldecode instead, though.
 404                                         $m[1] = urldecode( ltrim( $m[1], ':' ) );
 405                                 }
 406                                 $title = Title::newFromText( $m[1] );
 407                                 // If the title is a redirect to bad special pages or is invalid, return null
 408                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 409                                         return null;
 410                                 }
 411                                 return $title;
 412                         }
 413                 }
 414                 return null;
 415         }
 416
 417 # ----------------------------------------------------------------------------
 418 #       Static functions
 419 # ----------------------------------------------------------------------------
 420
 421         /**
 422          * Get the prefixed DB key associated with an ID
 423          *
 424          * @param $id \type{\int} the page_id of the article
 425          * @return \type{Title} an object representing the article, or NULL
 426          *  if no such article was found
 427          */
 428         public static function nameOf( $id ) {
 429                 $dbr = wfGetDB( DB_SLAVE );
 430
 431                 $s = $dbr->selectRow( 'page',
 432                         array( 'page_namespace', 'page_title' ),
 433                         array( 'page_id' => $id ),
 434                         __METHOD__ );
 435                 if ( $s === false ) { return null; }
 436
 437                 $n = self::makeName( $s->page_namespace, $s->page_title );
 438                 return $n;
 439         }
 440
 441         /**
 442          * Get a regex character class describing the legal characters in a link
 443          *
 444          * @return \type{\string} the list of characters, not delimited
 445          */
 446         public static function legalChars() {
 447                 global $wgLegalTitleChars;
 448                 return $wgLegalTitleChars;
 449         }
 450
 451         /**
 452          * Get a string representation of a title suitable for
 453          * including in a search index
 454          *
 455          * @param $ns \type{\int} a namespace index
 456          * @param $title \type{\string} text-form main part
 457          * @return \type{\string} a stripped-down title string ready for the
 458          *  search index
 459          */
 460         public static function indexTitle( $ns, $title ) {
 461                 global $wgContLang;
 462
 463                 $lc = SearchEngine::legalSearchChars() . '&#;';
 464                 $t = $wgContLang->normalizeForSearch( $title );
 465                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 466                 $t = $wgContLang->lc( $t );
 467
 468                 # Handle 's, s'
 469                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 470                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 471
 472                 $t = preg_replace( "/\\s+/", ' ', $t );
 473
 474                 if ( $ns == NS_FILE ) {
 475                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 476                 }
 477                 return trim( $t );
 478         }
 479
 480         /**
 481          * Make a prefixed DB key from a DB key and a namespace index
 482          *
 483          * @param $ns \type{\int} numerical representation of the namespace
 484          * @param $title \type{\string} the DB key form the title
 485          * @param $fragment \type{\string} The link fragment (after the "#")
 486          * @param $interwiki \type{\string} The interwiki prefix
 487          * @return \type{\string} the prefixed form of the title
 488          */
 489         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 490                 global $wgContLang;
 491
 492                 $namespace = $wgContLang->getNsText( $ns );
 493                 $name = $namespace == '' ? $title : "$namespace:$title";
 494                 if ( strval( $interwiki ) != '' ) {
 495                         $name = "$interwiki:$name";
 496                 }
 497                 if ( strval( $fragment ) != '' ) {
 498                         $name .= '#' . $fragment;
 499                 }
 500                 return $name;
 501         }
 502
 503         /**
 504          * Determine whether the object refers to a page within
 505          * this project.
 506          *
 507          * @return \type{\bool} TRUE if this is an in-project interwiki link
 508          *      or a wikilink, FALSE otherwise
 509          */
 510         public function isLocal() {
 511                 if ( $this->mInterwiki != '' ) {
 512                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 513                 } else {
 514                         return true;
 515                 }
 516         }
 517
 518         /**
 519          * Determine whether the object refers to a page within
 520          * this project and is transcludable.
 521          *
 522          * @return \type{\bool} TRUE if this is transcludable
 523          */
 524         public function isTrans() {
 525                 if ( $this->mInterwiki == '' )
 526                         return false;
 527
 528                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 529         }
 530
 531         /**
 532          * Returns the DB name of the distant wiki
 533          * which owns the object.
 534          *
 535          * @return \type{\string} the DB name
 536          */
 537         public function getTransWikiID() {
 538                 if ( $this->mInterwiki == '' )
 539                         return false;
 540
 541                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 542         }
 543
 544         /**
 545          * Escape a text fragment, say from a link, for a URL
 546          *
 547          * @param $fragment string containing a URL or link fragment (after the "#")
 548          * @return String: escaped string
 549          */
 550         static function escapeFragmentForURL( $fragment ) {
 551                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 552                 # fragments appear not to work in IE (at least up to 7) or in at least
 553                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 554                 # to care if they aren't encoded.
 555                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 556         }
 557
 558 # ----------------------------------------------------------------------------
 559 #       Other stuff
 560 # ----------------------------------------------------------------------------
 561
 562         /** Simple accessors */
 563         /**
 564          * Get the text form (spaces not underscores) of the main part
 565          *
 566          * @return \type{\string} Main part of the title
 567          */
 568         public function getText() { return $this->mTextform; }
 569
 570         /**
 571          * Get the URL-encoded form of the main part
 572          *
 573          * @return \type{\string} Main part of the title, URL-encoded
 574          */
 575         public function getPartialURL() { return $this->mUrlform; }
 576
 577         /**
 578          * Get the main part with underscores
 579          *
 580          * @return \type{\string} Main part of the title, with underscores
 581          */
 582         public function getDBkey() { return $this->mDbkeyform; }
 583
 584         /**
 585          * Get the namespace index, i.e.\ one of the NS_xxxx constants.
 586          *
 587          * @return \type{\int} Namespace index
 588          */
 589         public function getNamespace() { return $this->mNamespace; }
 590
 591         /**
 592          * Get the namespace text
 593          *
 594          * @return \type{\string} Namespace text
 595          */
 596         public function getNsText() {
 597                 global $wgContLang;
 598
 599                 if ( $this->mInterwiki != '' ) {
 600                         // This probably shouldn't even happen. ohh man, oh yuck.
 601                         // But for interwiki transclusion it sometimes does.
 602                         // Shit. Shit shit shit.
 603                         //
 604                         // Use the canonical namespaces if possible to try to
 605                         // resolve a foreign namespace.
 606                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 607                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 608                         }
 609                 }
 610                 return $wgContLang->getNsText( $this->mNamespace );
 611         }
 612
 613         /**
 614          * Get the DB key with the initial letter case as specified by the user
 615          *
 616          * @return \type{\string} DB key
 617          */
 618         function getUserCaseDBKey() {
 619                 return $this->mUserCaseDBKey;
 620         }
 621
 622         /**
 623          * Get the namespace text of the subject (rather than talk) page
 624          *
 625          * @return \type{\string} Namespace text
 626          */
 627         public function getSubjectNsText() {
 628                 global $wgContLang;
 629                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 630         }
 631
 632         /**
 633          * Get the namespace text of the talk page
 634          *
 635          * @return \type{\string} Namespace text
 636          */
 637         public function getTalkNsText() {
 638                 global $wgContLang;
 639                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 640         }
 641
 642         /**
 643          * Could this title have a corresponding talk page?
 644          *
 645          * @return \type{\bool} TRUE or FALSE
 646          */
 647         public function canTalk() {
 648                 return( MWNamespace::canTalk( $this->mNamespace ) );
 649         }
 650
 651         /**
 652          * Get the interwiki prefix (or null string)
 653          *
 654          * @return \type{\string} Interwiki prefix
 655          */
 656         public function getInterwiki() { return $this->mInterwiki; }
 657
 658         /**
 659          * Get the Title fragment (i.e.\ the bit after the #) in text form
 660          *
 661          * @return \type{\string} Title fragment
 662          */
 663         public function getFragment() { return $this->mFragment; }
 664
 665         /**
 666          * Get the fragment in URL form, including the "#" character if there is one
 667          * @return \type{\string} Fragment in URL form
 668          */
 669         public function getFragmentForURL() {
 670                 if ( $this->mFragment == '' ) {
 671                         return '';
 672                 } else {
 673                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 674                 }
 675         }
 676
 677         /**
 678          * Get the default namespace index, for when there is no namespace
 679          *
 680          * @return \type{\int} Default namespace index
 681          */
 682         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 683
 684         /**
 685          * Get title for search index
 686          *
 687          * @return \type{\string} a stripped-down title string ready for the
 688          *  search index
 689          */
 690         public function getIndexTitle() {
 691                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 692         }
 693
 694         /**
 695          * Get the prefixed database key form
 696          *
 697          * @return \type{\string} the prefixed title, with underscores and
 698          *  any interwiki and namespace prefixes
 699          */
 700         public function getPrefixedDBkey() {
 701                 $s = $this->prefix( $this->mDbkeyform );
 702                 $s = str_replace( ' ', '_', $s );
 703                 return $s;
 704         }
 705
 706         /**
 707          * Get the prefixed title with spaces.
 708          * This is the form usually used for display
 709          *
 710          * @return \type{\string} the prefixed title, with spaces
 711          */
 712         public function getPrefixedText() {
 713                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 714                         $s = $this->prefix( $this->mTextform );
 715                         $s = str_replace( '_', ' ', $s );
 716                         $this->mPrefixedText = $s;
 717                 }
 718                 return $this->mPrefixedText;
 719         }
 720
 721         /**
 722          * Get the prefixed title with spaces, plus any fragment
 723          * (part beginning with '#')
 724          *
 725          * @return \type{\string} the prefixed title, with spaces and
 726          *  the fragment, including '#'
 727          */
 728         public function getFullText() {
 729                 $text = $this->getPrefixedText();
 730                 if ( $this->mFragment != '' ) {
 731                         $text .= '#' . $this->mFragment;
 732                 }
 733                 return $text;
 734         }
 735
 736         /**
 737          * Get the base name, i.e. the leftmost parts before the /
 738          *
 739          * @return \type{\string} Base name
 740          */
 741         public function getBaseText() {
 742                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 743                         return $this->getText();
 744                 }
 745
 746                 $parts = explode( '/', $this->getText() );
 747                 # Don't discard the real title if there's no subpage involved
 748                 if ( count( $parts ) > 1 )
 749                         unset( $parts[ count( $parts ) - 1 ] );
 750                 return implode( '/', $parts );
 751         }
 752
 753         /**
 754          * Get the lowest-level subpage name, i.e. the rightmost part after /
 755          *
 756          * @return \type{\string} Subpage name
 757          */
 758         public function getSubpageText() {
 759                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 760                         return( $this->mTextform );
 761                 }
 762                 $parts = explode( '/', $this->mTextform );
 763                 return( $parts[ count( $parts ) - 1 ] );
 764         }
 765
 766         /**
 767          * Get a URL-encoded form of the subpage text
 768          *
 769          * @return \type{\string} URL-encoded subpage name
 770          */
 771         public function getSubpageUrlForm() {
 772                 $text = $this->getSubpageText();
 773                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 774                 return( $text );
 775         }
 776
 777         /**
 778          * Get a URL-encoded title (not an actual URL) including interwiki
 779          *
 780          * @return \type{\string} the URL-encoded form
 781          */
 782         public function getPrefixedURL() {
 783                 $s = $this->prefix( $this->mDbkeyform );
 784                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 785                 return $s;
 786         }
 787
 788         /**
 789          * Get a real URL referring to this title, with interwiki link and
 790          * fragment
 791          *
 792          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 793          *   links. Can be specified as an associative array as well, e.g.,
 794          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 795          * @param $variant \type{\string} language variant of url (for sr, zh..)
 796          * @return \type{\string} the URL
 797          */
 798         public function getFullURL( $query = '', $variant = false ) {
 799                 global $wgServer, $wgRequest;
 800
 801                 if ( is_array( $query ) ) {
 802                         $query = wfArrayToCGI( $query );
 803                 }
 804
 805                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 806                 if ( !$interwiki ) {
 807                         $url = $this->getLocalURL( $query, $variant );
 808
 809                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 810                         // Correct fix would be to move the prepending elsewhere.
 811                         if ( $wgRequest->getVal( 'action' ) != 'render' ) {
 812                                 $url = $wgServer . $url;
 813                         }
 814                 } else {
 815                         $baseUrl = $interwiki->getURL( );
 816
 817                         $namespace = wfUrlencode( $this->getNsText() );
 818                         if ( $namespace != '' ) {
 819                                 # Can this actually happen? Interwikis shouldn't be parsed.
 820                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 821                                 $namespace .= ':';
 822                         }
 823                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 824                         $url = wfAppendQuery( $url, $query );
 825                 }
 826
 827                 # Finally, add the fragment.
 828                 $url .= $this->getFragmentForURL();
 829
 830                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 831                 return $url;
 832         }
 833
 834         /**
 835          * Get a URL with no fragment or server name.  If this page is generated
 836          * with action=render, $wgServer is prepended.
 837          *
 838          * @param $query Mixed: an optional query string; if not specified,
 839          *   $wgArticlePath will be used.  Can be specified as an associative array
 840          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 841          *   URL-escaped).
 842          * @param $variant \type{\string} language variant of url (for sr, zh..)
 843          * @return \type{\string} the URL
 844          */
 845         public function getLocalURL( $query = '', $variant = false ) {
 846                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 847                 global $wgVariantArticlePath, $wgContLang, $wgUser;
 848
 849                 if ( is_array( $query ) ) {
 850                         $query = wfArrayToCGI( $query );
 851                 }
 852
 853                 // internal links should point to same variant as current page (only anonymous users)
 854                 if ( !$variant && $wgContLang->hasVariants() && !$wgUser->isLoggedIn() ) {
 855                         $pref = $wgContLang->getPreferredVariant( false );
 856                         if ( $pref != $wgContLang->getCode() )
 857                                 $variant = $pref;
 858                 }
 859
 860                 if ( $this->isExternal() ) {
 861                         $url = $this->getFullURL();
 862                         if ( $query ) {
 863                                 // This is currently only used for edit section links in the
 864                                 // context of interwiki transclusion. In theory we should
 865                                 // append the query to the end of any existing query string,
 866                                 // but interwiki transclusion is already broken in that case.
 867                                 $url .= "?$query";
 868                         }
 869                 } else {
 870                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 871                         if ( $query == '' ) {
 872                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 873                                         if ( !$wgVariantArticlePath ) {
 874                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 875                                         } else {
 876                                                 $variantArticlePath = $wgVariantArticlePath;
 877                                         }
 878                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 879                                         $url = str_replace( '$1', $dbkey, $url  );
 880                                 } else {
 881                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 882                                 }
 883                         } else {
 884                                 global $wgActionPaths;
 885                                 $url = false;
 886                                 $matches = array();
 887                                 if ( !empty( $wgActionPaths ) &&
 888                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 889                                 {
 890                                         $action = urldecode( $matches[2] );
 891                                         if ( isset( $wgActionPaths[$action] ) ) {
 892                                                 $query = $matches[1];
 893                                                 if ( isset( $matches[4] ) ) $query .= $matches[4];
 894                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 895                                                 if ( $query != '' ) {
 896                                                         $url = wfAppendQuery( $url, $query );
 897                                                 }
 898                                         }
 899                                 }
 900                                 if ( $url === false ) {
 901                                         if ( $query == '-' ) {
 902                                                 $query = '';
 903                                         }
 904                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 905                                 }
 906                         }
 907
 908                         // FIXME: this causes breakage in various places when we
 909                         // actually expected a local URL and end up with dupe prefixes.
 910                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 911                                 $url = $wgServer . $url;
 912                         }
 913                 }
 914                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 915                 return $url;
 916         }
 917
 918         /**
 919          * Get a URL that's the simplest URL that will be valid to link, locally,
 920          * to the current Title.  It includes the fragment, but does not include
 921          * the server unless action=render is used (or the link is external).  If
 922          * there's a fragment but the prefixed text is empty, we just return a link
 923          * to the fragment.
 924          *
 925          * The result obviously should not be URL-escaped, but does need to be
 926          * HTML-escaped if it's being output in HTML.
 927          *
 928          * @param $query \type{\arrayof{\string}} An associative array of key => value pairs for the
 929          *   query string.  Keys and values will be escaped.
 930          * @param $variant \type{\string} Language variant of URL (for sr, zh..).  Ignored
 931          *   for external links.  Default is "false" (same variant as current page,
 932          *   for anonymous users).
 933          * @return \type{\string} the URL
 934          */
 935         public function getLinkUrl( $query = array(), $variant = false ) {
 936                 wfProfileIn( __METHOD__ );
 937                 if ( $this->isExternal() ) {
 938                         $ret = $this->getFullURL( $query );
 939                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 940                         $ret = $this->getFragmentForURL();
 941                 } else {
 942                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 943                 }
 944                 wfProfileOut( __METHOD__ );
 945                 return $ret;
 946         }
 947
 948         /**
 949          * Get an HTML-escaped version of the URL form, suitable for
 950          * using in a link, without a server name or fragment
 951          *
 952          * @param $query \type{\string} an optional query string
 953          * @return \type{\string} the URL
 954          */
 955         public function escapeLocalURL( $query = '' ) {
 956                 return htmlspecialchars( $this->getLocalURL( $query ) );
 957         }
 958
 959         /**
 960          * Get an HTML-escaped version of the URL form, suitable for
 961          * using in a link, including the server name and fragment
 962          *
 963          * @param $query \type{\string} an optional query string
 964          * @return \type{\string} the URL
 965          */
 966         public function escapeFullURL( $query = '' ) {
 967                 return htmlspecialchars( $this->getFullURL( $query ) );
 968         }
 969
 970         /**
 971          * Get the URL form for an internal link.
 972          * - Used in various Squid-related code, in case we have a different
 973          * internal hostname for the server from the exposed one.
 974          *
 975          * @param $query \type{\string} an optional query string
 976          * @param $variant \type{\string} language variant of url (for sr, zh..)
 977          * @return \type{\string} the URL
 978          */
 979         public function getInternalURL( $query = '', $variant = false ) {
 980                 global $wgInternalServer;
 981                 $url = $wgInternalServer . $this->getLocalURL( $query, $variant );
 982                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
 983                 return $url;
 984         }
 985
 986         /**
 987          * Get the edit URL for this Title
 988          *
 989          * @return \type{\string} the URL, or a null string if this is an
 990          *  interwiki link
 991          */
 992         public function getEditURL() {
 993                 if ( $this->mInterwiki != '' ) { return ''; }
 994                 $s = $this->getLocalURL( 'action=edit' );
 995
 996                 return $s;
 997         }
 998
 999         /**
1000          * Get the HTML-escaped displayable text form.
1001          * Used for the title field in <a> tags.
1002          *
1003          * @return \type{\string} the text, including any prefixes
1004          */
1005         public function getEscapedText() {
1006                 return htmlspecialchars( $this->getPrefixedText() );
1007         }
1008
1009         /**
1010          * Is this Title interwiki?
1011          *
1012          * @return \type{\bool}
1013          */
1014         public function isExternal() { return ( $this->mInterwiki != '' ); }
1015
1016         /**
1017          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1018          *
1019          * @param $action \type{\string} Action to check (default: edit)
1020          * @return \type{\bool}
1021          */
1022         public function isSemiProtected( $action = 'edit' ) {
1023                 if ( $this->exists() ) {
1024                         $restrictions = $this->getRestrictions( $action );
1025                         if ( count( $restrictions ) > 0 ) {
1026                                 foreach ( $restrictions as $restriction ) {
1027                                         if ( strtolower( $restriction ) != 'autoconfirmed' )
1028                                                 return false;
1029                                 }
1030                         } else {
1031                                 # Not protected
1032                                 return false;
1033                         }
1034                         return true;
1035                 } else {
1036                         # If it doesn't exist, it can't be protected
1037                         return false;
1038                 }
1039         }
1040
1041         /**
1042          * Does the title correspond to a protected article?
1043          *
1044          * @param $action \type{\string} the action the page is protected from,
1045          * by default checks all actions.
1046          * @return \type{\bool}
1047          */
1048         public function isProtected( $action = '' ) {
1049                 global $wgRestrictionLevels;
1050
1051                 $restrictionTypes = $this->getRestrictionTypes();
1052
1053                 # Special pages have inherent protection
1054                 if( $this->getNamespace() == NS_SPECIAL )
1055                         return true;
1056
1057                 # Check regular protection levels
1058                 foreach ( $restrictionTypes as $type ) {
1059                         if ( $action == $type || $action == '' ) {
1060                                 $r = $this->getRestrictions( $type );
1061                                 foreach ( $wgRestrictionLevels as $level ) {
1062                                         if ( in_array( $level, $r ) && $level != '' ) {
1063                                                 return true;
1064                                         }
1065                                 }
1066                         }
1067                 }
1068
1069                 return false;
1070         }
1071
1072         /**
1073          * Is this a conversion table for the LanguageConverter?
1074          *
1075          * @return \type{\bool}
1076          */
1077         public function isConversionTable() {
1078                 if($this->getNamespace() == NS_MEDIAWIKI
1079                    && strpos( $this->getText(), 'Conversiontable' ) !== false ) {
1080                         return true;
1081                 }
1082
1083                 return false;
1084         }
1085
1086         /**
1087          * Is $wgUser watching this page?
1088          *
1089          * @return \type{\bool}
1090          */
1091         public function userIsWatching() {
1092                 global $wgUser;
1093
1094                 if ( is_null( $this->mWatched ) ) {
1095                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1096                                 $this->mWatched = false;
1097                         } else {
1098                                 $this->mWatched = $wgUser->isWatched( $this );
1099                         }
1100                 }
1101                 return $this->mWatched;
1102         }
1103
1104         /**
1105          * Can $wgUser perform $action on this page?
1106          * This skips potentially expensive cascading permission checks
1107          * as well as avoids expensive error formatting
1108          *
1109          * Suitable for use for nonessential UI controls in common cases, but
1110          * _not_ for functional access control.
1111          *
1112          * May provide false positives, but should never provide a false negative.
1113          *
1114          * @param $action \type{\string} action that permission needs to be checked for
1115          * @return \type{\bool}
1116          */
1117         public function quickUserCan( $action ) {
1118                 return $this->userCan( $action, false );
1119         }
1120
1121         /**
1122          * Determines if $wgUser is unable to edit this page because it has been protected
1123          * by $wgNamespaceProtection.
1124          *
1125          * @return \type{\bool}
1126          */
1127         public function isNamespaceProtected() {
1128                 global $wgNamespaceProtection, $wgUser;
1129                 if ( isset( $wgNamespaceProtection[ $this->mNamespace ] ) ) {
1130                         foreach ( (array)$wgNamespaceProtection[ $this->mNamespace ] as $right ) {
1131                                 if ( $right != '' && !$wgUser->isAllowed( $right ) )
1132                                         return true;
1133                         }
1134                 }
1135                 return false;
1136         }
1137
1138         /**
1139          * Can $wgUser perform $action on this page?
1140          *
1141          * @param $action \type{\string} action that permission needs to be checked for
1142          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1143          * @return \type{\bool}
1144          */
1145         public function userCan( $action, $doExpensiveQueries = true ) {
1146                 global $wgUser;
1147                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1148         }
1149
1150         /**
1151          * Can $user perform $action on this page?
1152          *
1153          * FIXME: This *does not* check throttles (User::pingLimiter()).
1154          *
1155          * @param $action \type{\string}action that permission needs to be checked for
1156          * @param $user \type{User} user to check
1157          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1158          * @param $ignoreErrors \type{\arrayof{\string}} Set this to a list of message keys whose corresponding errors may be ignored.
1159          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1160          */
1161         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1162                 if ( !StubObject::isRealObject( $user ) ) {
1163                         // Since StubObject is always used on globals, we can
1164                         // unstub $wgUser here and set $user = $wgUser
1165                         global $wgUser;
1166                         $wgUser->_unstub( '', 5 );
1167                         $user = $wgUser;
1168                 }
1169
1170                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1171
1172                 // Remove the errors being ignored.
1173                 foreach ( $errors as $index => $error ) {
1174                         $error_key = is_array( $error ) ? $error[0] : $error;
1175
1176                         if ( in_array( $error_key, $ignoreErrors ) ) {
1177                                 unset( $errors[$index] );
1178                         }
1179                 }
1180
1181                 return $errors;
1182         }
1183
1184         /**
1185          * Permissions checks that fail most often, and which are easiest to test.
1186          *
1187          * @param $action String the action to check
1188          * @param $user User user to check
1189          * @param $errors Array list of current errors
1190          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1191          * @param $short Boolean short circuit on first error
1192          *
1193          * @return Array list of errors
1194          */
1195         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1196                 if ( $action == 'create' ) {
1197                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1198                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1199                                 $errors[] = $user->isAnon() ? array ( 'nocreatetext' ) : array ( 'nocreate-loggedin' );
1200                         }
1201                 } elseif ( $action == 'move' ) {
1202                         if ( !$user->isAllowed( 'move-rootuserpages' )
1203                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1204                                 // Show user page-specific message only if the user can move other pages
1205                                 $errors[] = array( 'cant-move-user-page' );
1206                         }
1207
1208                         // Check if user is allowed to move files if it's a file
1209                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1210                                 $errors[] = array( 'movenotallowedfile' );
1211                         }
1212
1213                         if ( !$user->isAllowed( 'move' ) ) {
1214                                 // User can't move anything
1215                                 global $wgGroupPermissions;
1216                                 $userCanMove = false;
1217                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1218                                         $userCanMove = $wgGroupPermissions['user']['move'];
1219                                 }
1220                                 $autoconfirmedCanMove = false;
1221                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1222                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1223                                 }
1224                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1225                                         // custom message if logged-in users without any special rights can move
1226                                         $errors[] = array ( 'movenologintext' );
1227                                 } else {
1228                                         $errors[] = array ( 'movenotallowed' );
1229                                 }
1230                         }
1231                 } elseif ( $action == 'move-target' ) {
1232                         if ( !$user->isAllowed( 'move' ) ) {
1233                                 // User can't move anything
1234                                 $errors[] = array ( 'movenotallowed' );
1235                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1236                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1237                                 // Show user page-specific message only if the user can move other pages
1238                                 $errors[] = array( 'cant-move-to-user-page' );
1239                         }
1240                 } elseif ( !$user->isAllowed( $action ) ) {
1241                         $return = null;
1242
1243                         // We avoid expensive display logic for quickUserCan's and such
1244                         $groups = false;
1245                         if ( !$short ) {
1246                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1247                                         User::getGroupsWithPermission( $action ) );
1248                         }
1249
1250                         if ( $groups ) {
1251                                 global $wgLang;
1252                                 $return = array(
1253                                         'badaccess-groups',
1254                                         $wgLang->commaList( $groups ),
1255                                         count( $groups )
1256                                 );
1257                         } else {
1258                                 $return = array( "badaccess-group0" );
1259                         }
1260                         $errors[] = $return;
1261                 }
1262
1263                 return $errors;
1264         }
1265
1266         /**
1267          * Add the resulting error code to the errors array
1268          *
1269          * @param $errors Array list of current errors
1270          * @param $result Mixed result of errors
1271          *
1272          * @return Array list of errors
1273          */
1274         private function resultToError( $errors, $result ) {
1275                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1276                         // A single array representing an error
1277                         $errors[] = $result;
1278                 } else if ( is_array( $result ) && is_array( $result[0] ) ) {
1279                         // A nested array representing multiple errors
1280                         $errors = array_merge( $errors, $result );
1281                 } else if ( $result !== '' && is_string( $result ) ) {
1282                         // A string representing a message-id
1283                         $errors[] = array( $result );
1284                 } else if ( $result === false ) {
1285                         // a generic "We don't want them to do that"
1286                         $errors[] = array( 'badaccess-group0' );
1287                 }
1288                 return $errors;
1289         }
1290
1291         /**
1292          * Check various permission hooks
1293          * @see checkQuickPermissions for parameter information
1294          */
1295         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1296                 // Use getUserPermissionsErrors instead
1297                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1298                         return $result ? array() : array( array( 'badaccess-group0' ) );
1299                 }
1300                 // Check getUserPermissionsErrors hook
1301                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1302                         $errors = $this->resultToError( $errors, $result );
1303                 }
1304                 // Check getUserPermissionsErrorsExpensive hook
1305                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1306                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1307                         $errors = $this->resultToError( $errors, $result );
1308                 }
1309
1310                 return $errors;
1311         }
1312
1313         /**
1314          * Check permissions on special pages & namespaces
1315          * @see checkQuickPermissions for parameter information
1316          */
1317         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1318                 # Only 'createaccount' and 'execute' can be performed on
1319                 # special pages, which don't actually exist in the DB.
1320                 $specialOKActions = array( 'createaccount', 'execute' );
1321                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1322                         $errors[] = array( 'ns-specialprotected' );
1323                 }
1324
1325                 # Check $wgNamespaceProtection for restricted namespaces
1326                 if ( $this->isNamespaceProtected() ) {
1327                         $ns = $this->mNamespace == NS_MAIN ?
1328                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1329                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1330                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1331                 }
1332
1333                 return $errors;
1334         }
1335
1336         /**
1337          * Check CSS/JS sub-page permissions
1338          * @see checkQuickPermissions for parameter information
1339          */
1340         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1341                 # Protect css/js subpages of user pages
1342                 # XXX: this might be better using restrictions
1343                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssSubpage()
1344                 #      and $this->userCanEditJsSubpage() from working
1345                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1346                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1347                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1348                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1349                                 $errors[] = array( 'customcssjsprotected' );
1350                         } else if ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1351                                 $errors[] = array( 'customcssjsprotected' );
1352                         }
1353                 }
1354
1355                 return $errors;
1356         }
1357
1358         /**
1359          * Check against page_restrictions table requirements on this
1360          * page. The user must possess all required rights for this
1361          * action.
1362          * @see checkQuickPermissions for parameter information
1363          */
1364         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1365                 foreach ( $this->getRestrictions( $action ) as $right ) {
1366                         // Backwards compatibility, rewrite sysop -> protect
1367                         if ( $right == 'sysop' ) {
1368                                 $right = 'protect';
1369                         }
1370                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1371                                 // Users with 'editprotected' permission can edit protected pages
1372                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected' ) ) {
1373                                         // Users with 'editprotected' permission cannot edit protected pages
1374                                         // with cascading option turned on.
1375                                         if ( $this->mCascadeRestriction ) {
1376                                                 $errors[] = array( 'protectedpagetext', $right );
1377                                         }
1378                                 } else {
1379                                         $errors[] = array( 'protectedpagetext', $right );
1380                                 }
1381                         }
1382                 }
1383
1384                 return $errors;
1385         }
1386
1387         /**
1388          * Check restrictions on cascading pages.
1389          * @see checkQuickPermissions for parameter information
1390          */
1391         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1392                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1393                         # We /could/ use the protection level on the source page, but it's
1394                         # fairly ugly as we have to establish a precedence hierarchy for pages
1395                         # included by multiple cascade-protected pages. So just restrict
1396                         # it to people with 'protect' permission, as they could remove the
1397                         # protection anyway.
1398                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1399                         # Cascading protection depends on more than this page...
1400                         # Several cascading protected pages may include this page...
1401                         # Check each cascading level
1402                         # This is only for protection restrictions, not for all actions
1403                         if ( isset( $restrictions[$action] ) ) {
1404                                 foreach ( $restrictions[$action] as $right ) {
1405                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1406                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1407                                                 $pages = '';
1408                                                 foreach ( $cascadingSources as $page )
1409                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1410                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1411                                         }
1412                                 }
1413                         }
1414                 }
1415
1416                 return $errors;
1417         }
1418
1419         /**
1420          * Check action permissions not already checked in checkQuickPermissions
1421          * @see checkQuickPermissions for parameter information
1422          */
1423         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1424                 if ( $action == 'protect' ) {
1425                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1426                                 // If they can't edit, they shouldn't protect.
1427                                 $errors[] = array( 'protect-cantedit' );
1428                         }
1429                 } elseif ( $action == 'create' ) {
1430                         $title_protection = $this->getTitleProtection();
1431                         if( $title_protection ) {
1432                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1433                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1434                                 }
1435                                 if( $title_protection['pt_create_perm'] == '' || !$user->isAllowed( $title_protection['pt_create_perm'] ) ) {
1436                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1437                                 }
1438                         }
1439                 } elseif ( $action == 'move' ) {
1440                         // Check for immobile pages
1441                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1442                                 // Specific message for this case
1443                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1444                         } elseif ( !$this->isMovable() ) {
1445                                 // Less specific message for rarer cases
1446                                 $errors[] = array( 'immobile-page' );
1447                         }
1448                 } elseif ( $action == 'move-target' ) {
1449                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1450                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1451                         } elseif ( !$this->isMovable() ) {
1452                                 $errors[] = array( 'immobile-target-page' );
1453                         }
1454                 }
1455                 return $errors;
1456         }
1457
1458         /**
1459          * Check that the user isn't blocked from editting.
1460          * @see checkQuickPermissions for parameter information
1461          */
1462         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1463                 if( $short ) {
1464                         return $errors;
1465                 }
1466
1467                 global $wgContLang;
1468                 global $wgLang;
1469                 global $wgEmailConfirmToEdit;
1470
1471                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1472                         $errors[] = array( 'confirmedittext' );
1473                 }
1474
1475                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1476                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1477                         $block = $user->mBlock;
1478
1479                         // This is from OutputPage::blockedPage
1480                         // Copied at r23888 by werdna
1481
1482                         $id = $user->blockedBy();
1483                         $reason = $user->blockedFor();
1484                         if ( $reason == '' ) {
1485                                 $reason = wfMsg( 'blockednoreason' );
1486                         }
1487                         $ip = wfGetIP();
1488
1489                         if ( is_numeric( $id ) ) {
1490                                 $name = User::whoIs( $id );
1491                         } else {
1492                                 $name = $id;
1493                         }
1494
1495                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1496                         $blockid = $block->mId;
1497                         $blockExpiry = $user->mBlock->mExpiry;
1498                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1499                         if ( $blockExpiry == 'infinity' ) {
1500                                 // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
1501                                 $scBlockExpiryOptions = wfMsg( 'ipboptions' );
1502
1503                                 foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
1504                                         if ( !strpos( $option, ':' ) )
1505                                                 continue;
1506
1507                                         list ( $show, $value ) = explode( ":", $option );
1508
1509                                         if ( $value == 'infinite' || $value == 'indefinite' ) {
1510                                                 $blockExpiry = $show;
1511                                                 break;
1512                                         }
1513                                 }
1514                         } else {
1515                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1516                         }
1517
1518                         $intended = $user->mBlock->mAddress;
1519
1520                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1521                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1522                 }
1523
1524                 return $errors;
1525         }
1526
1527         /**
1528          * Can $user perform $action on this page? This is an internal function,
1529          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1530          * checks on wfReadOnly() and blocks)
1531          *
1532          * @param $action \type{\string} action that permission needs to be checked for
1533          * @param $user \type{User} user to check
1534          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1535          * @param $short \type{\bool} Set this to true to stop after the first permission error.
1536          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1537          */
1538         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1539                 wfProfileIn( __METHOD__ );
1540
1541                 $errors = array();
1542                 $checks = array( 'checkQuickPermissions',
1543                         'checkPermissionHooks',
1544                         'checkSpecialsAndNSPermissions',
1545                         'checkCSSandJSPermissions',
1546                         'checkPageRestrictions',
1547                         'checkCascadingSourcesRestrictions',
1548                         'checkActionPermissions',
1549                         'checkUserBlock' );
1550
1551                 while( count( $checks ) > 0 &&
1552                            !( $short && count( $errors ) > 0 ) ) {
1553                         $method = array_shift( $checks );
1554                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1555                 }
1556
1557                 wfProfileOut( __METHOD__ );
1558                 return $errors;
1559         }
1560
1561         /**
1562          * Is this title subject to title protection?
1563          *
1564          * @return \type{\mixed} An associative array representing any existent title
1565          *   protection, or false if there's none.
1566          */
1567         private function getTitleProtection() {
1568                 // Can't protect pages in special namespaces
1569                 if ( $this->getNamespace() < 0 ) {
1570                         return false;
1571                 }
1572
1573                 // Can't protect pages that exist.
1574                 if ( $this->exists() ) {
1575                         return false;
1576                 }
1577
1578                 if ( !isset( $this->mTitleProtection ) ) {
1579                         $dbr = wfGetDB( DB_SLAVE );
1580                         $res = $dbr->select( 'protected_titles', '*',
1581                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1582                                 __METHOD__ );
1583
1584                         // fetchRow returns false if there are no rows.
1585                         $this->mTitleProtection = $dbr->fetchRow( $res );
1586                 }
1587                 return $this->mTitleProtection;
1588         }
1589
1590         /**
1591          * Update the title protection status
1592          *
1593          * @param $create_perm \type{\string} Permission required for creation
1594          * @param $reason \type{\string} Reason for protection
1595          * @param $expiry \type{\string} Expiry timestamp
1596          * @return boolean true
1597          */
1598         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1599                 global $wgUser, $wgContLang;
1600
1601                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1602                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1603                         // No change
1604                         return true;
1605                 }
1606
1607                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1608
1609                 $dbw = wfGetDB( DB_MASTER );
1610
1611                 $encodedExpiry = Block::encodeExpiry( $expiry, $dbw );
1612
1613                 $expiry_description = '';
1614                 if ( $encodedExpiry != 'infinity' ) {
1615                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1616                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1617                 }
1618                 else {
1619                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1620                 }
1621
1622                 # Update protection table
1623                 if ( $create_perm != '' ) {
1624                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1625                                 array(
1626                                         'pt_namespace' => $namespace,
1627                                         'pt_title' => $title,
1628                                         'pt_create_perm' => $create_perm,
1629                                         'pt_timestamp' => Block::encodeExpiry( wfTimestampNow(), $dbw ),
1630                                         'pt_expiry' => $encodedExpiry,
1631                                         'pt_user' => $wgUser->getId(),
1632                                         'pt_reason' => $reason,
1633                                 ), __METHOD__
1634                         );
1635                 } else {
1636                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1637                                 'pt_title' => $title ), __METHOD__ );
1638                 }
1639                 # Update the protection log
1640                 if ( $dbw->affectedRows() ) {
1641                         $log = new LogPage( 'protect' );
1642
1643                         if ( $create_perm ) {
1644                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1645                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1646                         } else {
1647                                 $log->addEntry( 'unprotect', $this, $reason );
1648                         }
1649                 }
1650
1651                 return true;
1652         }
1653
1654         /**
1655          * Remove any title protection due to page existing
1656          */
1657         public function deleteTitleProtection() {
1658                 $dbw = wfGetDB( DB_MASTER );
1659
1660                 $dbw->delete( 'protected_titles',
1661                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1662                         __METHOD__ );
1663         }
1664
1665         /**
1666          * Would anybody with sufficient privileges be able to move this page?
1667          * Some pages just aren't movable.
1668          *
1669          * @return \type{\bool} TRUE or FALSE
1670          */
1671         public function isMovable() {
1672                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1673         }
1674
1675         /**
1676          * Can $wgUser read this page?
1677          *
1678          * @return \type{\bool}
1679          * @todo fold these checks into userCan()
1680          */
1681         public function userCanRead() {
1682                 global $wgUser, $wgGroupPermissions;
1683
1684                 static $useShortcut = null;
1685
1686                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1687                 if ( is_null( $useShortcut ) ) {
1688                         global $wgRevokePermissions;
1689                         $useShortcut = true;
1690                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1691                                 # Not a public wiki, so no shortcut
1692                                 $useShortcut = false;
1693                         } elseif ( !empty( $wgRevokePermissions ) ) {
1694                                 /*
1695                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1696                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1697                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1698                                  * reading is allowed.
1699                                  */
1700                                 foreach ( $wgRevokePermissions as $perms ) {
1701                                         if ( !empty( $perms['read'] ) ) {
1702                                                 # We might be removing the read right from the user, so no shortcut
1703                                                 $useShortcut = false;
1704                                                 break;
1705                                         }
1706                                 }
1707                         }
1708                 }
1709
1710                 $result = null;
1711                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1712                 if ( $result !== null ) {
1713                         return $result;
1714                 }
1715
1716                 # Shortcut for public wikis, allows skipping quite a bit of code
1717                 if ( $useShortcut )
1718                         return true;
1719
1720                 if ( $wgUser->isAllowed( 'read' ) ) {
1721                         return true;
1722                 } else {
1723                         global $wgWhitelistRead;
1724
1725                         /**
1726                          * Always grant access to the login page.
1727                          * Even anons need to be able to log in.
1728                         */
1729                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1730                                 return true;
1731                         }
1732
1733                         /**
1734                          * Bail out if there isn't whitelist
1735                          */
1736                         if ( !is_array( $wgWhitelistRead ) ) {
1737                                 return false;
1738                         }
1739
1740                         /**
1741                          * Check for explicit whitelisting
1742                          */
1743                         $name = $this->getPrefixedText();
1744                         $dbName = $this->getPrefixedDBKey();
1745                         // Check with and without underscores
1746                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1747                                 return true;
1748
1749                         /**
1750                          * Old settings might have the title prefixed with
1751                          * a colon for main-namespace pages
1752                          */
1753                         if ( $this->getNamespace() == NS_MAIN ) {
1754                                 if ( in_array( ':' . $name, $wgWhitelistRead ) )
1755                                         return true;
1756                         }
1757
1758                         /**
1759                          * If it's a special page, ditch the subpage bit
1760                          * and check again
1761                          */
1762                         if ( $this->getNamespace() == NS_SPECIAL ) {
1763                                 $name = $this->getDBkey();
1764                                 list( $name, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $name );
1765                                 if ( $name === false ) {
1766                                         # Invalid special page, but we show standard login required message
1767                                         return false;
1768                                 }
1769
1770                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1771                                 if ( in_array( $pure, $wgWhitelistRead, true ) )
1772                                         return true;
1773                         }
1774
1775                 }
1776                 return false;
1777         }
1778
1779         /**
1780          * Is this a talk page of some sort?
1781          *
1782          * @return \type{\bool}
1783          */
1784         public function isTalkPage() {
1785                 return MWNamespace::isTalk( $this->getNamespace() );
1786         }
1787
1788         /**
1789          * Is this a subpage?
1790          *
1791          * @return \type{\bool}
1792          */
1793         public function isSubpage() {
1794                 return MWNamespace::hasSubpages( $this->mNamespace )
1795                         ? strpos( $this->getText(), '/' ) !== false
1796                         : false;
1797         }
1798
1799         /**
1800          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1801          *
1802          * @return \type{\bool}
1803          */
1804         public function hasSubpages() {
1805                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1806                         # Duh
1807                         return false;
1808                 }
1809
1810                 # We dynamically add a member variable for the purpose of this method
1811                 # alone to cache the result.  There's no point in having it hanging
1812                 # around uninitialized in every Title object; therefore we only add it
1813                 # if needed and don't declare it statically.
1814                 if ( isset( $this->mHasSubpages ) ) {
1815                         return $this->mHasSubpages;
1816                 }
1817
1818                 $subpages = $this->getSubpages( 1 );
1819                 if ( $subpages instanceof TitleArray )
1820                         return $this->mHasSubpages = (bool)$subpages->count();
1821                 return $this->mHasSubpages = false;
1822         }
1823
1824         /**
1825          * Get all subpages of this page.
1826          *
1827          * @param $limit Maximum number of subpages to fetch; -1 for no limit
1828          * @return mixed TitleArray, or empty array if this page's namespace
1829          *  doesn't allow subpages
1830          */
1831         public function getSubpages( $limit = -1 ) {
1832                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) )
1833                         return array();
1834
1835                 $dbr = wfGetDB( DB_SLAVE );
1836                 $conds['page_namespace'] = $this->getNamespace();
1837                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1838                 $options = array();
1839                 if ( $limit > -1 )
1840                         $options['LIMIT'] = $limit;
1841                 return $this->mSubpages = TitleArray::newFromResult(
1842                         $dbr->select( 'page',
1843                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1844                                 $conds,
1845                                 __METHOD__,
1846                                 $options
1847                         )
1848                 );
1849         }
1850
1851         /**
1852          * Could this page contain custom CSS or JavaScript, based
1853          * on the title?
1854          *
1855          * @return \type{\bool}
1856          */
1857         public function isCssOrJsPage() {
1858                 return $this->mNamespace == NS_MEDIAWIKI
1859                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1860         }
1861
1862         /**
1863          * Is this a .css or .js subpage of a user page?
1864          * @return \type{\bool}
1865          */
1866         public function isCssJsSubpage() {
1867                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1868         }
1869
1870         /**
1871          * Is this a *valid* .css or .js subpage of a user page?
1872          * Check that the corresponding skin exists
1873          *
1874          * @return \type{\bool}
1875          */
1876         public function isValidCssJsSubpage() {
1877                 if ( $this->isCssJsSubpage() ) {
1878                         $name = $this->getSkinFromCssJsSubpage();
1879                         if ( $name == 'common' ) return true;
1880                         $skinNames = Skin::getSkinNames();
1881                         return array_key_exists( $name, $skinNames );
1882                 } else {
1883                         return false;
1884                 }
1885         }
1886
1887         /**
1888          * Trim down a .css or .js subpage title to get the corresponding skin name
1889          *
1890          * @return string containing skin name from .css or .js subpage title
1891          */
1892         public function getSkinFromCssJsSubpage() {
1893                 $subpage = explode( '/', $this->mTextform );
1894                 $subpage = $subpage[ count( $subpage ) - 1 ];
1895                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1896         }
1897
1898         /**
1899          * Is this a .css subpage of a user page?
1900          *
1901          * @return \type{\bool}
1902          */
1903         public function isCssSubpage() {
1904                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1905         }
1906
1907         /**
1908          * Is this a .js subpage of a user page?
1909          *
1910          * @return \type{\bool}
1911          */
1912         public function isJsSubpage() {
1913                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1914         }
1915
1916         /**
1917          * Protect css subpages of user pages: can $wgUser edit
1918          * this page?
1919          *
1920          * @return \type{\bool}
1921          * @todo XXX: this might be better using restrictions
1922          */
1923         public function userCanEditCssSubpage() {
1924                 global $wgUser;
1925                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'editusercss' ) )
1926                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1927         }
1928         /**
1929          * Protect js subpages of user pages: can $wgUser edit
1930          * this page?
1931          *
1932          * @return \type{\bool}
1933          * @todo XXX: this might be better using restrictions
1934          */
1935         public function userCanEditJsSubpage() {
1936                 global $wgUser;
1937                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'edituserjs' ) )
1938                        || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1939         }
1940
1941         /**
1942          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
1943          *
1944          * @return \type{\bool} If the page is subject to cascading restrictions.
1945          */
1946         public function isCascadeProtected() {
1947                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
1948                 return ( $sources > 0 );
1949         }
1950
1951         /**
1952          * Cascading protection: Get the source of any cascading restrictions on this page.
1953          *
1954          * @param $getPages \type{\bool} Whether or not to retrieve the actual pages
1955          *        that the restrictions have come from.
1956          * @return \type{\arrayof{mixed title array, restriction array}} Array of the Title
1957          *         objects of the pages from which cascading restrictions have come,
1958          *         false for none, or true if such restrictions exist, but $getPages was not set.
1959          *         The restriction array is an array of each type, each of which contains a
1960          *         array of unique groups.
1961          */
1962         public function getCascadeProtectionSources( $getPages = true ) {
1963                 $pagerestrictions = array();
1964
1965                 if ( isset( $this->mCascadeSources ) && $getPages ) {
1966                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
1967                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
1968                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
1969                 }
1970
1971                 wfProfileIn( __METHOD__ );
1972
1973                 $dbr = wfGetDB( DB_SLAVE );
1974
1975                 if ( $this->getNamespace() == NS_FILE ) {
1976                         $tables = array ( 'imagelinks', 'page_restrictions' );
1977                         $where_clauses = array(
1978                                 'il_to' => $this->getDBkey(),
1979                                 'il_from=pr_page',
1980                                 'pr_cascade' => 1 );
1981                 } else {
1982                         $tables = array ( 'templatelinks', 'page_restrictions' );
1983                         $where_clauses = array(
1984                                 'tl_namespace' => $this->getNamespace(),
1985                                 'tl_title' => $this->getDBkey(),
1986                                 'tl_from=pr_page',
1987                                 'pr_cascade' => 1 );
1988                 }
1989
1990                 if ( $getPages ) {
1991                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
1992                                                    'pr_expiry', 'pr_type', 'pr_level' );
1993                         $where_clauses[] = 'page_id=pr_page';
1994                         $tables[] = 'page';
1995                 } else {
1996                         $cols = array( 'pr_expiry' );
1997                 }
1998
1999                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2000
2001                 $sources = $getPages ? array() : false;
2002                 $now = wfTimestampNow();
2003                 $purgeExpired = false;
2004
2005                 foreach ( $res as $row ) {
2006                         $expiry = Block::decodeExpiry( $row->pr_expiry );
2007                         if ( $expiry > $now ) {
2008                                 if ( $getPages ) {
2009                                         $page_id = $row->pr_page;
2010                                         $page_ns = $row->page_namespace;
2011                                         $page_title = $row->page_title;
2012                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2013                                         # Add groups needed for each restriction type if its not already there
2014                                         # Make sure this restriction type still exists
2015
2016                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2017                                                 $pagerestrictions[$row->pr_type] = array();
2018                                         }
2019
2020                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2021                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2022                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2023                                         }
2024                                 } else {
2025                                         $sources = true;
2026                                 }
2027                         } else {
2028                                 // Trigger lazy purge of expired restrictions from the db
2029                                 $purgeExpired = true;
2030                         }
2031                 }
2032                 if ( $purgeExpired ) {
2033                         Title::purgeExpiredRestrictions();
2034                 }
2035
2036                 wfProfileOut( __METHOD__ );
2037
2038                 if ( $getPages ) {
2039                         $this->mCascadeSources = $sources;
2040                         $this->mCascadingRestrictions = $pagerestrictions;
2041                 } else {
2042                         $this->mHasCascadingRestrictions = $sources;
2043                 }
2044
2045                 return array( $sources, $pagerestrictions );
2046         }
2047
2048         /**
2049          * Returns cascading restrictions for the current article
2050          *
2051          * @return Boolean
2052          */
2053         function areRestrictionsCascading() {
2054                 if ( !$this->mRestrictionsLoaded ) {
2055                         $this->loadRestrictions();
2056                 }
2057
2058                 return $this->mCascadeRestriction;
2059         }
2060
2061         /**
2062          * Loads a string into mRestrictions array
2063          *
2064          * @param $res \type{Resource} restrictions as an SQL result.
2065          * @param $oldFashionedRestrictions string comma-separated list of page
2066          *        restrictions from page table (pre 1.10)
2067          */
2068         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2069                 $rows = array();
2070                 $dbr = wfGetDB( DB_SLAVE );
2071
2072                 while ( $row = $dbr->fetchObject( $res ) ) {
2073                         $rows[] = $row;
2074                 }
2075
2076                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2077         }
2078
2079         /**
2080          * Compiles list of active page restrictions from both page table (pre 1.10)
2081          * and page_restrictions table
2082          *
2083          * @param $rows array of db result objects
2084          * @param $oldFashionedRestrictions string comma-separated list of page
2085          *        restrictions from page table (pre 1.10)
2086          */
2087         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2088                 $dbr = wfGetDB( DB_SLAVE );
2089
2090                 $restrictionTypes = $this->getRestrictionTypes();
2091
2092                 foreach ( $restrictionTypes as $type ) {
2093                         $this->mRestrictions[$type] = array();
2094                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry( '' );
2095                 }
2096
2097                 $this->mCascadeRestriction = false;
2098
2099                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2100
2101                 if ( $oldFashionedRestrictions === null ) {
2102                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2103                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2104                 }
2105
2106                 if ( $oldFashionedRestrictions != '' ) {
2107
2108                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2109                                 $temp = explode( '=', trim( $restrict ) );
2110                                 if ( count( $temp ) == 1 ) {
2111                                         // old old format should be treated as edit/move restriction
2112                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2113                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2114                                 } else {
2115                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2116                                 }
2117                         }
2118
2119                         $this->mOldRestrictions = true;
2120
2121                 }
2122
2123                 if ( count( $rows ) ) {
2124                         # Current system - load second to make them override.
2125                         $now = wfTimestampNow();
2126                         $purgeExpired = false;
2127
2128                         foreach ( $rows as $row ) {
2129                                 # Cycle through all the restrictions.
2130
2131                                 // Don't take care of restrictions types that aren't allowed
2132
2133                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2134                                         continue;
2135
2136                                 // This code should be refactored, now that it's being used more generally,
2137                                 // But I don't really see any harm in leaving it in Block for now -werdna
2138                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
2139
2140                                 // Only apply the restrictions if they haven't expired!
2141                                 if ( !$expiry || $expiry > $now ) {
2142                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2143                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2144
2145                                         $this->mCascadeRestriction |= $row->pr_cascade;
2146                                 } else {
2147                                         // Trigger a lazy purge of expired restrictions
2148                                         $purgeExpired = true;
2149                                 }
2150                         }
2151
2152                         if ( $purgeExpired ) {
2153                                 Title::purgeExpiredRestrictions();
2154                         }
2155                 }
2156
2157                 $this->mRestrictionsLoaded = true;
2158         }
2159
2160         /**
2161          * Load restrictions from the page_restrictions table
2162          *
2163          * @param $oldFashionedRestrictions string comma-separated list of page
2164          *        restrictions from page table (pre 1.10)
2165          */
2166         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2167                 if ( !$this->mRestrictionsLoaded ) {
2168                         if ( $this->exists() ) {
2169                                 $dbr = wfGetDB( DB_SLAVE );
2170
2171                                 $res = $dbr->select( 'page_restrictions', '*',
2172                                         array ( 'pr_page' => $this->getArticleId() ), __METHOD__ );
2173
2174                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2175                         } else {
2176                                 $title_protection = $this->getTitleProtection();
2177
2178                                 if ( $title_protection ) {
2179                                         $now = wfTimestampNow();
2180                                         $expiry = Block::decodeExpiry( $title_protection['pt_expiry'] );
2181
2182                                         if ( !$expiry || $expiry > $now ) {
2183                                                 // Apply the restrictions
2184                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2185                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2186                                         } else { // Get rid of the old restrictions
2187                                                 Title::purgeExpiredRestrictions();
2188                                         }
2189                                 } else {
2190                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry( '' );
2191                                 }
2192                                 $this->mRestrictionsLoaded = true;
2193                         }
2194                 }
2195         }
2196
2197         /**
2198          * Purge expired restrictions from the page_restrictions table
2199          */
2200         static function purgeExpiredRestrictions() {
2201                 $dbw = wfGetDB( DB_MASTER );
2202                 $dbw->delete( 'page_restrictions',
2203                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2204                         __METHOD__ );
2205
2206                 $dbw->delete( 'protected_titles',
2207                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2208                         __METHOD__ );
2209         }
2210
2211         /**
2212          * Accessor/initialisation for mRestrictions
2213          *
2214          * @param $action \type{\string} action that permission needs to be checked for
2215          * @return \type{\arrayof{\string}} the array of groups allowed to edit this article
2216          */
2217         public function getRestrictions( $action ) {
2218                 if ( !$this->mRestrictionsLoaded ) {
2219                         $this->loadRestrictions();
2220                 }
2221                 return isset( $this->mRestrictions[$action] )
2222                                 ? $this->mRestrictions[$action]
2223                                 : array();
2224         }
2225
2226         /**
2227          * Get the expiry time for the restriction against a given action
2228          *
2229          * @return 14-char timestamp, or 'infinity' if the page is protected forever
2230          *      or not protected at all, or false if the action is not recognised.
2231          */
2232         public function getRestrictionExpiry( $action ) {
2233                 if ( !$this->mRestrictionsLoaded ) {
2234                         $this->loadRestrictions();
2235                 }
2236                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2237         }
2238
2239         /**
2240          * Is there a version of this page in the deletion archive?
2241          *
2242          * @return \type{\int} the number of archived revisions
2243          */
2244         public function isDeleted() {
2245                 if ( $this->getNamespace() < 0 ) {
2246                         $n = 0;
2247                 } else {
2248                         $dbr = wfGetDB( DB_SLAVE );
2249                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2250                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2251                                 __METHOD__
2252                         );
2253                         if ( $this->getNamespace() == NS_FILE ) {
2254                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2255                                         array( 'fa_name' => $this->getDBkey() ),
2256                                         __METHOD__
2257                                 );
2258                         }
2259                 }
2260                 return (int)$n;
2261         }
2262
2263         /**
2264          * Is there a version of this page in the deletion archive?
2265          *
2266          * @return Boolean
2267          */
2268         public function isDeletedQuick() {
2269                 if ( $this->getNamespace() < 0 ) {
2270                         return false;
2271                 }
2272                 $dbr = wfGetDB( DB_SLAVE );
2273                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2274                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2275                         __METHOD__
2276                 );
2277                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2278                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2279                                 array( 'fa_name' => $this->getDBkey() ),
2280                                 __METHOD__
2281                         );
2282                 }
2283                 return $deleted;
2284         }
2285
2286         /**
2287          * Get the article ID for this Title from the link cache,
2288          * adding it if necessary
2289          *
2290          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select
2291          *  for update
2292          * @return \type{\int} the ID
2293          */
2294         public function getArticleID( $flags = 0 ) {
2295                 if ( $this->getNamespace() < 0 ) {
2296                         return $this->mArticleID = 0;
2297                 }
2298                 $linkCache = LinkCache::singleton();
2299                 if ( $flags & GAID_FOR_UPDATE ) {
2300                         $oldUpdate = $linkCache->forUpdate( true );
2301                         $linkCache->clearLink( $this );
2302                         $this->mArticleID = $linkCache->addLinkObj( $this );
2303                         $linkCache->forUpdate( $oldUpdate );
2304                 } else {
2305                         if ( -1 == $this->mArticleID ) {
2306                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2307                         }
2308                 }
2309                 return $this->mArticleID;
2310         }
2311
2312         /**
2313          * Is this an article that is a redirect page?
2314          * Uses link cache, adding it if necessary
2315          *
2316          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2317          * @return \type{\bool}
2318          */
2319         public function isRedirect( $flags = 0 ) {
2320                 if ( !is_null( $this->mRedirect ) )
2321                         return $this->mRedirect;
2322                 # Calling getArticleID() loads the field from cache as needed
2323                 if ( !$this->getArticleID( $flags ) ) {
2324                         return $this->mRedirect = false;
2325                 }
2326                 $linkCache = LinkCache::singleton();
2327                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2328
2329                 return $this->mRedirect;
2330         }
2331
2332         /**
2333          * What is the length of this page?
2334          * Uses link cache, adding it if necessary
2335          *
2336          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2337          * @return \type{\bool}
2338          */
2339         public function getLength( $flags = 0 ) {
2340                 if ( $this->mLength != -1 )
2341                         return $this->mLength;
2342                 # Calling getArticleID() loads the field from cache as needed
2343                 if ( !$this->getArticleID( $flags ) ) {
2344                         return $this->mLength = 0;
2345                 }
2346                 $linkCache = LinkCache::singleton();
2347                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2348
2349                 return $this->mLength;
2350         }
2351
2352         /**
2353          * What is the page_latest field for this page?
2354          *
2355          * @param $flags \type{\int} a bit field; may be GAID_FOR_UPDATE to select for update
2356          * @return \type{\int} or 0 if the page doesn't exist
2357          */
2358         public function getLatestRevID( $flags = 0 ) {
2359                 if ( $this->mLatestID !== false )
2360                         return intval( $this->mLatestID );
2361                 # Calling getArticleID() loads the field from cache as needed
2362                 if ( !$this->getArticleID( $flags ) ) {
2363                         return $this->mLatestID = 0;
2364                 }
2365                 $linkCache = LinkCache::singleton();
2366                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2367
2368                 return $this->mLatestID;
2369         }
2370
2371         /**
2372          * This clears some fields in this object, and clears any associated
2373          * keys in the "bad links" section of the link cache.
2374          *
2375          * @param $newid \type{\int} the new Article ID
2376          */
2377         public function resetArticleID( $newid ) {
2378                 $linkCache = LinkCache::singleton();
2379                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2380
2381                 if ( $newid === false ) {
2382                         $this->mArticleID = -1;
2383                 } else {
2384                         $this->mArticleID = intval( $newid );
2385                 }
2386                 $this->mRestrictionsLoaded = false;
2387                 $this->mRestrictions = array();
2388                 $this->mRedirect = null;
2389                 $this->mLength = -1;
2390                 $this->mLatestID = false;
2391         }
2392
2393         /**
2394          * Updates page_touched for this page; called from LinksUpdate.php
2395          *
2396          * @return \type{\bool} true if the update succeded
2397          */
2398         public function invalidateCache() {
2399                 if ( wfReadOnly() ) {
2400                         return;
2401                 }
2402                 $dbw = wfGetDB( DB_MASTER );
2403                 $success = $dbw->update( 'page',
2404                         array( 'page_touched' => $dbw->timestamp() ),
2405                         $this->pageCond(),
2406                         __METHOD__
2407                 );
2408                 HTMLFileCache::clearFileCache( $this );
2409                 return $success;
2410         }
2411
2412         /**
2413          * Prefix some arbitrary text with the namespace or interwiki prefix
2414          * of this object
2415          *
2416          * @param $name \type{\string} the text
2417          * @return \type{\string} the prefixed text
2418          * @private
2419          */
2420         /* private */ function prefix( $name ) {
2421                 $p = '';
2422                 if ( $this->mInterwiki != '' ) {
2423                         $p = $this->mInterwiki . ':';
2424                 }
2425                 if ( 0 != $this->mNamespace ) {
2426                         $p .= $this->getNsText() . ':';
2427                 }
2428                 return $p . $name;
2429         }
2430
2431         /**
2432          * Returns a simple regex that will match on characters and sequences invalid in titles.
2433          * Note that this doesn't pick up many things that could be wrong with titles, but that
2434          * replacing this regex with something valid will make many titles valid.
2435          *
2436          * @return string regex string
2437          */
2438         static function getTitleInvalidRegex() {
2439                 static $rxTc = false;
2440                 if ( !$rxTc ) {
2441                         # Matching titles will be held as illegal.
2442                         $rxTc = '/' .
2443                                 # Any character not allowed is forbidden...
2444                                 '[^' . Title::legalChars() . ']' .
2445                                 # URL percent encoding sequences interfere with the ability
2446                                 # to round-trip titles -- you can't link to them consistently.
2447                                 '|%[0-9A-Fa-f]{2}' .
2448                                 # XML/HTML character references produce similar issues.
2449                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2450                                 '|&#[0-9]+;' .
2451                                 '|&#x[0-9A-Fa-f]+;' .
2452                                 '/S';
2453                 }
2454
2455                 return $rxTc;
2456         }
2457
2458         /**
2459          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2460          *
2461          * @param $text string containing title to capitalize
2462          * @param $ns int namespace index, defaults to NS_MAIN
2463          * @return String containing capitalized title
2464          */
2465         public static function capitalize( $text, $ns = NS_MAIN ) {
2466                 global $wgContLang;
2467
2468                 if ( MWNamespace::isCapitalized( $ns ) )
2469                         return $wgContLang->ucfirst( $text );
2470                 else
2471                         return $text;
2472         }
2473
2474         /**
2475          * Secure and split - main initialisation function for this object
2476          *
2477          * Assumes that mDbkeyform has been set, and is urldecoded
2478          * and uses underscores, but not otherwise munged.  This function
2479          * removes illegal characters, splits off the interwiki and
2480          * namespace prefixes, sets the other forms, and canonicalizes
2481          * everything.
2482          *
2483          * @return \type{\bool} true on success
2484          */
2485         private function secureAndSplit() {
2486                 global $wgContLang, $wgLocalInterwiki;
2487
2488                 # Initialisation
2489                 $rxTc = self::getTitleInvalidRegex();
2490
2491                 $this->mInterwiki = $this->mFragment = '';
2492                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2493
2494                 $dbkey = $this->mDbkeyform;
2495
2496                 # Strip Unicode bidi override characters.
2497                 # Sometimes they slip into cut-n-pasted page titles, where the
2498                 # override chars get included in list displays.
2499                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2500
2501                 # Clean up whitespace
2502                 # Note: use of the /u option on preg_replace here will cause
2503                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2504                 # conveniently disabling them.
2505                 #
2506                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2507                 $dbkey = trim( $dbkey, '_' );
2508
2509                 if ( $dbkey == '' ) {
2510                         return false;
2511                 }
2512
2513                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2514                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2515                         return false;
2516                 }
2517
2518                 $this->mDbkeyform = $dbkey;
2519
2520                 # Initial colon indicates main namespace rather than specified default
2521                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2522                 if ( ':' == $dbkey { 0 } ) {
2523                         $this->mNamespace = NS_MAIN;
2524                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2525                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2526                 }
2527
2528                 # Namespace or interwiki prefix
2529                 $firstPass = true;
2530                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2531                 do {
2532                         $m = array();
2533                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2534                                 $p = $m[1];
2535                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2536                                         # Ordinary namespace
2537                                         $dbkey = $m[2];
2538                                         $this->mNamespace = $ns;
2539                                         # For Talk:X pages, check if X has a "namespace" prefix
2540                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2541                                                 if ( $wgContLang->getNsIndex( $x[1] ) )
2542                                                         return false; # Disallow Talk:File:x type titles...
2543                                                 else if ( Interwiki::isValidInterwiki( $x[1] ) )
2544                                                         return false; # Disallow Talk:Interwiki:x type titles...
2545                                         }
2546                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2547                                         if ( !$firstPass ) {
2548                                                 # Can't make a local interwiki link to an interwiki link.
2549                                                 # That's just crazy!
2550                                                 return false;
2551                                         }
2552
2553                                         # Interwiki link
2554                                         $dbkey = $m[2];
2555                                         $this->mInterwiki = $wgContLang->lc( $p );
2556
2557                                         # Redundant interwiki prefix to the local wiki
2558                                         if ( 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) ) {
2559                                                 if ( $dbkey == '' ) {
2560                                                         # Can't have an empty self-link
2561                                                         return false;
2562                                                 }
2563                                                 $this->mInterwiki = '';
2564                                                 $firstPass = false;
2565                                                 # Do another namespace split...
2566                                                 continue;
2567                                         }
2568
2569                                         # If there's an initial colon after the interwiki, that also
2570                                         # resets the default namespace
2571                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2572                                                 $this->mNamespace = NS_MAIN;
2573                                                 $dbkey = substr( $dbkey, 1 );
2574                                         }
2575                                 }
2576                                 # If there's no recognized interwiki or namespace,
2577                                 # then let the colon expression be part of the title.
2578                         }
2579                         break;
2580                 } while ( true );
2581
2582                 # We already know that some pages won't be in the database!
2583                 #
2584                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2585                         $this->mArticleID = 0;
2586                 }
2587                 $fragment = strstr( $dbkey, '#' );
2588                 if ( false !== $fragment ) {
2589                         $this->setFragment( preg_replace( '/^#_*/', '#', $fragment ) );
2590                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2591                         # remove whitespace again: prevents "Foo_bar_#"
2592                         # becoming "Foo_bar_"
2593                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2594                 }
2595
2596                 # Reject illegal characters.
2597                 #
2598                 if ( preg_match( $rxTc, $dbkey ) ) {
2599                         return false;
2600                 }
2601
2602                 /**
2603                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2604                  * reachable due to the way web browsers deal with 'relative' URLs.
2605                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2606                  */
2607                 if ( strpos( $dbkey, '.' ) !== false &&
2608                      ( $dbkey === '.' || $dbkey === '..' ||
2609                        strpos( $dbkey, './' ) === 0  ||
2610                        strpos( $dbkey, '../' ) === 0 ||
2611                        strpos( $dbkey, '/./' ) !== false ||
2612                        strpos( $dbkey, '/../' ) !== false  ||
2613                        substr( $dbkey, -2 ) == '/.' ||
2614                        substr( $dbkey, -3 ) == '/..' ) )
2615                 {
2616                         return false;
2617                 }
2618
2619                 /**
2620                  * Magic tilde sequences? Nu-uh!
2621                  */
2622                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2623                         return false;
2624                 }
2625
2626                 /**
2627                  * Limit the size of titles to 255 bytes.
2628                  * This is typically the size of the underlying database field.
2629                  * We make an exception for special pages, which don't need to be stored
2630                  * in the database, and may edge over 255 bytes due to subpage syntax
2631                  * for long titles, e.g. [[Special:Block/Long name]]
2632                  */
2633                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2634                   strlen( $dbkey ) > 512 )
2635                 {
2636                         return false;
2637                 }
2638
2639                 /**
2640                  * Normally, all wiki links are forced to have
2641                  * an initial capital letter so [[foo]] and [[Foo]]
2642                  * point to the same place.
2643                  *
2644                  * Don't force it for interwikis, since the other
2645                  * site might be case-sensitive.
2646                  */
2647                 $this->mUserCaseDBKey = $dbkey;
2648                 if (  $this->mInterwiki == '' ) {
2649                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2650                 }
2651
2652                 /**
2653                  * Can't make a link to a namespace alone...
2654                  * "empty" local links can only be self-links
2655                  * with a fragment identifier.
2656                  */
2657                 if ( $dbkey == '' &&
2658                         $this->mInterwiki == '' &&
2659                         $this->mNamespace != NS_MAIN ) {
2660                         return false;
2661                 }
2662                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2663                 // IP names are not allowed for accounts, and can only be referring to
2664                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2665                 // there are numerous ways to present the same IP. Having sp:contribs scan
2666                 // them all is silly and having some show the edits and others not is
2667                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2668                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK ) ?
2669                         IP::sanitizeIP( $dbkey ) : $dbkey;
2670                 // Any remaining initial :s are illegal.
2671                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2672                         return false;
2673                 }
2674
2675                 # Fill fields
2676                 $this->mDbkeyform = $dbkey;
2677                 $this->mUrlform = wfUrlencode( $dbkey );
2678
2679                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2680
2681                 return true;
2682         }
2683
2684         /**
2685          * Set the fragment for this title. Removes the first character from the
2686          * specified fragment before setting, so it assumes you're passing it with
2687          * an initial "#".
2688          *
2689          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2690          * Still in active use privately.
2691          *
2692          * @param $fragment \type{\string} text
2693          */
2694         public function setFragment( $fragment ) {
2695                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2696         }
2697
2698         /**
2699          * Get a Title object associated with the talk page of this article
2700          *
2701          * @return \type{Title} the object for the talk page
2702          */
2703         public function getTalkPage() {
2704                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2705         }
2706
2707         /**
2708          * Get a title object associated with the subject page of this
2709          * talk page
2710          *
2711          * @return \type{Title} the object for the subject page
2712          */
2713         public function getSubjectPage() {
2714                 // Is this the same title?
2715                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2716                 if ( $this->getNamespace() == $subjectNS ) {
2717                         return $this;
2718                 }
2719                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2720         }
2721
2722         /**
2723          * Get an array of Title objects linking to this Title
2724          * Also stores the IDs in the link cache.
2725          *
2726          * WARNING: do not use this function on arbitrary user-supplied titles!
2727          * On heavily-used templates it will max out the memory.
2728          *
2729          * @param $options Array: may be FOR UPDATE
2730          * @param $table String: table name
2731          * @param $prefix String: fields prefix
2732          * @return \type{\arrayof{Title}} the Title objects linking here
2733          */
2734         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2735                 $linkCache = LinkCache::singleton();
2736
2737                 if ( count( $options ) > 0 ) {
2738                         $db = wfGetDB( DB_MASTER );
2739                 } else {
2740                         $db = wfGetDB( DB_SLAVE );
2741                 }
2742
2743                 $res = $db->select( array( 'page', $table ),
2744                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2745                         array(
2746                                 "{$prefix}_from=page_id",
2747                                 "{$prefix}_namespace" => $this->getNamespace(),
2748                                 "{$prefix}_title"     => $this->getDBkey() ),
2749                         __METHOD__,
2750                         $options );
2751
2752                 $retVal = array();
2753                 if ( $db->numRows( $res ) ) {
2754                         foreach ( $res as $row ) {
2755                                 if ( $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title ) ) {
2756                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2757                                         $retVal[] = $titleObj;
2758                                 }
2759                         }
2760                 }
2761                 $db->freeResult( $res );
2762                 return $retVal;
2763         }
2764
2765         /**
2766          * Get an array of Title objects using this Title as a template
2767          * Also stores the IDs in the link cache.
2768          *
2769          * WARNING: do not use this function on arbitrary user-supplied titles!
2770          * On heavily-used templates it will max out the memory.
2771          *
2772          * @param $options Array: may be FOR UPDATE
2773          * @return \type{\arrayof{Title}} the Title objects linking here
2774          */
2775         public function getTemplateLinksTo( $options = array() ) {
2776                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2777         }
2778
2779         /**
2780          * Get an array of Title objects referring to non-existent articles linked from this page
2781          *
2782          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2783          * @return \type{\arrayof{Title}} the Title objects
2784          */
2785         public function getBrokenLinksFrom() {
2786                 if ( $this->getArticleId() == 0 ) {
2787                         # All links from article ID 0 are false positives
2788                         return array();
2789                 }
2790
2791                 $dbr = wfGetDB( DB_SLAVE );
2792                 $res = $dbr->select(
2793                         array( 'page', 'pagelinks' ),
2794                         array( 'pl_namespace', 'pl_title' ),
2795                         array(
2796                                 'pl_from' => $this->getArticleId(),
2797                                 'page_namespace IS NULL'
2798                         ),
2799                         __METHOD__, array(),
2800                         array(
2801                                 'page' => array(
2802                                         'LEFT JOIN',
2803                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2804                                 )
2805                         )
2806                 );
2807
2808                 $retVal = array();
2809                 foreach ( $res as $row ) {
2810                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2811                 }
2812                 return $retVal;
2813         }
2814
2815
2816         /**
2817          * Get a list of URLs to purge from the Squid cache when this
2818          * page changes
2819          *
2820          * @return \type{\arrayof{\string}} the URLs
2821          */
2822         public function getSquidURLs() {
2823                 global $wgContLang;
2824
2825                 $urls = array(
2826                         $this->getInternalURL(),
2827                         $this->getInternalURL( 'action=history' )
2828                 );
2829
2830                 // purge variant urls as well
2831                 if ( $wgContLang->hasVariants() ) {
2832                         $variants = $wgContLang->getVariants();
2833                         foreach ( $variants as $vCode ) {
2834                                 $urls[] = $this->getInternalURL( '', $vCode );
2835                         }
2836                 }
2837
2838                 return $urls;
2839         }
2840
2841         /**
2842          * Purge all applicable Squid URLs
2843          */
2844         public function purgeSquid() {
2845                 global $wgUseSquid;
2846                 if ( $wgUseSquid ) {
2847                         $urls = $this->getSquidURLs();
2848                         $u = new SquidUpdate( $urls );
2849                         $u->doUpdate();
2850                 }
2851         }
2852
2853         /**
2854          * Move this page without authentication
2855          *
2856          * @param $nt \type{Title} the new page Title
2857          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2858          */
2859         public function moveNoAuth( &$nt ) {
2860                 return $this->moveTo( $nt, false );
2861         }
2862
2863         /**
2864          * Check whether a given move operation would be valid.
2865          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2866          *
2867          * @param $nt \type{Title} the new title
2868          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2869          *  should be checked
2870          * @param $reason \type{\string} is the log summary of the move, used for spam checking
2871          * @return \type{\mixed} True on success, getUserPermissionsErrors()-like array on failure
2872          */
2873         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2874                 global $wgUser;
2875
2876                 $errors = array();
2877                 if ( !$nt ) {
2878                         // Normally we'd add this to $errors, but we'll get
2879                         // lots of syntax errors if $nt is not an object
2880                         return array( array( 'badtitletext' ) );
2881                 }
2882                 if ( $this->equals( $nt ) ) {
2883                         $errors[] = array( 'selfmove' );
2884                 }
2885                 if ( !$this->isMovable() ) {
2886                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2887                 }
2888                 if ( $nt->getInterwiki() != '' ) {
2889                         $errors[] = array( 'immobile-target-namespace-iw' );
2890                 }
2891                 if ( !$nt->isMovable() ) {
2892                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
2893                 }
2894
2895                 $oldid = $this->getArticleID();
2896                 $newid = $nt->getArticleID();
2897
2898                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2899                         $errors[] = array( 'articleexists' );
2900                 }
2901                 if ( ( $this->getDBkey() == '' ) ||
2902                          ( !$oldid ) ||
2903                      ( $nt->getDBkey() == '' ) ) {
2904                         $errors[] = array( 'badarticleerror' );
2905                 }
2906
2907                 // Image-specific checks
2908                 if ( $this->getNamespace() == NS_FILE ) {
2909                         if ( $nt->getNamespace() != NS_FILE ) {
2910                                 $errors[] = array( 'imagenocrossnamespace' );
2911                         }
2912                         $file = wfLocalFile( $this );
2913                         if ( $file->exists() ) {
2914                                 if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
2915                                         $errors[] = array( 'imageinvalidfilename' );
2916                                 }
2917                                 if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
2918                                         $errors[] = array( 'imagetypemismatch' );
2919                                 }
2920                         }
2921                         $destfile = wfLocalFile( $nt );
2922                         if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destfile->exists() && wfFindFile( $nt ) ) {
2923                                 $errors[] = array( 'file-exists-sharedrepo' );
2924                         }
2925                 }
2926
2927                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
2928                         $errors[] = array( 'nonfile-cannot-move-to-file' );
2929                 }
2930
2931                 if ( $auth ) {
2932                         $errors = wfMergeErrorArrays( $errors,
2933                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
2934                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
2935                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
2936                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
2937                 }
2938
2939                 $match = EditPage::matchSummarySpamRegex( $reason );
2940                 if ( $match !== false ) {
2941                         // This is kind of lame, won't display nice
2942                         $errors[] = array( 'spamprotectiontext' );
2943                 }
2944
2945                 $err = null;
2946                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
2947                         $errors[] = array( 'hookaborted', $err );
2948                 }
2949
2950                 # The move is allowed only if (1) the target doesn't exist, or
2951                 # (2) the target is a redirect to the source, and has no history
2952                 # (so we can undo bad moves right after they're done).
2953
2954                 if ( 0 != $newid ) { # Target exists; check for validity
2955                         if ( !$this->isValidMoveTarget( $nt ) ) {
2956                                 $errors[] = array( 'articleexists' );
2957                         }
2958                 } else {
2959                         $tp = $nt->getTitleProtection();
2960                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
2961                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
2962                                 $errors[] = array( 'cantmove-titleprotected' );
2963                         }
2964                 }
2965                 if ( empty( $errors ) )
2966                         return true;
2967                 return $errors;
2968         }
2969
2970         /**
2971          * Move a title to a new location
2972          *
2973          * @param $nt \type{Title} the new title
2974          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2975          *  should be checked
2976          * @param $reason \type{\string} The reason for the move
2977          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title.
2978          *  Ignored if the user doesn't have the suppressredirect right.
2979          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2980          */
2981         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
2982                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
2983                 if ( is_array( $err ) ) {
2984                         return $err;
2985                 }
2986
2987                 // If it is a file, move it first. It is done before all other moving stuff is done because it's hard to revert
2988                 $dbw = wfGetDB( DB_MASTER );
2989                 if ( $this->getNamespace() == NS_FILE ) {
2990                         $file = wfLocalFile( $this );
2991                         if ( $file->exists() ) {
2992                                 $status = $file->move( $nt );
2993                                 if ( !$status->isOk() ) {
2994                                         return $status->getErrorsArray();
2995                                 }
2996                         }
2997                 }
2998
2999                 $pageid = $this->getArticleID();
3000                 $protected = $this->isProtected();
3001                 if ( $nt->exists() ) {
3002                         $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
3003                         $pageCountChange = ( $createRedirect ? 0 : -1 );
3004                 } else { # Target didn't exist, do normal move.
3005                         $err = $this->moveToNewTitle( $nt, $reason, $createRedirect );
3006                         $pageCountChange = ( $createRedirect ? 1 : 0 );
3007                 }
3008
3009                 if ( is_array( $err ) ) {
3010                         return $err;
3011                 }
3012                 $redirid = $this->getArticleID();
3013
3014                 // Category memberships include a sort key which may be customized.
3015                 // If it's left as the default (the page title), we need to update
3016                 // the sort key to match the new title.
3017                 //
3018                 // Be careful to avoid resetting cl_timestamp, which may disturb
3019                 // time-based lists on some sites.
3020                 //
3021                 // Warning -- if the sort key is *explicitly* set to the old title,
3022                 // we can't actually distinguish it from a default here, and it'll
3023                 // be set to the new title even though it really shouldn't.
3024                 // It'll get corrected on the next edit, but resetting cl_timestamp.
3025                 $dbw->update( 'categorylinks',
3026                         array(
3027                                 'cl_sortkey' => $nt->getPrefixedText(),
3028                                 'cl_timestamp=cl_timestamp' ),
3029                         array(
3030                                 'cl_from' => $pageid,
3031                                 'cl_sortkey' => $this->getPrefixedText() ),
3032                         __METHOD__ );
3033
3034                 if ( $protected ) {
3035                         # Protect the redirect title as the title used to be...
3036                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3037                                 array(
3038                                         'pr_page'    => $redirid,
3039                                         'pr_type'    => 'pr_type',
3040                                         'pr_level'   => 'pr_level',
3041                                         'pr_cascade' => 'pr_cascade',
3042                                         'pr_user'    => 'pr_user',
3043                                         'pr_expiry'  => 'pr_expiry'
3044                                 ),
3045                                 array( 'pr_page' => $pageid ),
3046                                 __METHOD__,
3047                                 array( 'IGNORE' )
3048                         );
3049                         # Update the protection log
3050                         $log = new LogPage( 'protect' );
3051                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3052                         if ( $reason ) $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3053                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) ); // FIXME: $params?
3054                 }
3055
3056                 # Update watchlists
3057                 $oldnamespace = $this->getNamespace() & ~1;
3058                 $newnamespace = $nt->getNamespace() & ~1;
3059                 $oldtitle = $this->getDBkey();
3060                 $newtitle = $nt->getDBkey();
3061
3062                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3063                         WatchedItem::duplicateEntries( $this, $nt );
3064                 }
3065
3066                 # Update search engine
3067                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3068                 $u->doUpdate();
3069                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3070                 $u->doUpdate();
3071
3072                 # Update site_stats
3073                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3074                         # No longer a content page
3075                         # Not viewed, edited, removing
3076                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3077                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3078                         # Now a content page
3079                         # Not viewed, edited, adding
3080                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3081                 } elseif ( $pageCountChange ) {
3082                         # Redirect added
3083                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3084                 } else {
3085                         # Nothing special
3086                         $u = false;
3087                 }
3088                 if ( $u )
3089                         $u->doUpdate();
3090                 # Update message cache for interface messages
3091                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3092                         global $wgMessageCache;
3093
3094                         # @bug 17860: old article can be deleted, if this the case,
3095                         # delete it from message cache
3096                         if ( $this->getArticleID() === 0 ) {
3097                                 $wgMessageCache->replace( $this->getDBkey(), false );
3098                         } else {
3099                                 $oldarticle = new Article( $this );
3100                                 $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
3101                         }
3102
3103                         $newarticle = new Article( $nt );
3104                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
3105                 }
3106
3107                 global $wgUser;
3108                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3109                 return true;
3110         }
3111
3112         /**
3113          * Move page to a title which is at present a redirect to the
3114          * source page
3115          *
3116          * @param $nt \type{Title} the page to move to, which should currently
3117          *  be a redirect
3118          * @param $reason \type{\string} The reason for the move
3119          * @param $createRedirect \type{\bool} Whether to leave a redirect at the old title.
3120          *  Ignored if the user doesn't have the suppressredirect right
3121          */
3122         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
3123                 global $wgUseSquid, $wgUser, $wgContLang;
3124
3125                 $comment = wfMsgForContent( '1movedto2_redir', $this->getPrefixedText(), $nt->getPrefixedText() );
3126
3127                 if ( $reason ) {
3128                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3129                 }
3130                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3131                 $comment = $wgContLang->truncate( $comment, 250 );
3132
3133                 $now = wfTimestampNow();
3134                 $newid = $nt->getArticleID();
3135                 $oldid = $this->getArticleID();
3136                 $latest = $this->getLatestRevID();
3137
3138                 $dbw = wfGetDB( DB_MASTER );
3139
3140                 $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3141                 $newns = $nt->getNamespace();
3142                 $newdbk = $nt->getDBkey();
3143
3144                 # Delete the old redirect. We don't save it to history since
3145                 # by definition if we've got here it's rather uninteresting.
3146                 # We have to remove it so that the next step doesn't trigger
3147                 # a conflict on the unique namespace+title index...
3148                 $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3149                 if ( !$dbw->cascadingDeletes() ) {
3150                         $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3151                         global $wgUseTrackbacks;
3152                         if ( $wgUseTrackbacks )
3153                                 $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3154                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3155                         $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3156                         $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3157                         $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3158                         $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3159                         $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3160                         $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3161                 }
3162                 // If the redirect was recently created, it may have an entry in recentchanges still
3163                 $dbw->delete( 'recentchanges',
3164                         array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3165                         __METHOD__
3166                 );
3167
3168                 # Save a null revision in the page's history notifying of the move
3169                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3170                 $nullRevId = $nullRevision->insertOn( $dbw );
3171
3172                 $article = new Article( $this );
3173                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3174
3175                 # Change the name of the target page:
3176                 $dbw->update( 'page',
3177                         /* SET */ array(
3178                                 'page_touched'   => $dbw->timestamp( $now ),
3179                                 'page_namespace' => $nt->getNamespace(),
3180                                 'page_title'     => $nt->getDBkey(),
3181                                 'page_latest'    => $nullRevId,
3182                         ),
3183                         /* WHERE */ array( 'page_id' => $oldid ),
3184                         __METHOD__
3185                 );
3186                 $nt->resetArticleID( $oldid );
3187
3188                 # Recreate the redirect, this time in the other direction.
3189                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3190                         $mwRedir = MagicWord::get( 'redirect' );
3191                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3192                         $redirectArticle = new Article( $this );
3193                         $newid = $redirectArticle->insertOn( $dbw );
3194                         $redirectRevision = new Revision( array(
3195                                 'page'    => $newid,
3196                                 'comment' => $comment,
3197                                 'text'    => $redirectText ) );
3198                         $redirectRevision->insertOn( $dbw );
3199                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3200
3201                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3202
3203                         # Now, we record the link from the redirect to the new title.
3204                         # It should have no other outgoing links...
3205                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3206                         $dbw->insert( 'pagelinks',
3207                                 array(
3208                                         'pl_from'      => $newid,
3209                                         'pl_namespace' => $nt->getNamespace(),
3210                                         'pl_title'     => $nt->getDBkey() ),
3211                                 __METHOD__ );
3212                         $redirectSuppressed = false;
3213                 } else {
3214                         $this->resetArticleID( 0 );
3215                         $redirectSuppressed = true;
3216                 }
3217
3218                 # Log the move
3219                 $log = new LogPage( 'move' );
3220                 $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3221
3222                 # Purge squid
3223                 if ( $wgUseSquid ) {
3224                         $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
3225                         $u = new SquidUpdate( $urls );
3226                         $u->doUpdate();
3227                 }
3228
3229         }
3230
3231         /**
3232          * Move page to non-existing title.
3233          *
3234          * @param $nt \type{Title} the new Title
3235          * @param $reason \type{\string} The reason for the move
3236          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title
3237          *  Ignored if the user doesn't have the suppressredirect right
3238          */
3239         private function moveToNewTitle( &$nt, $reason = '', $createRedirect = true ) {
3240                 global $wgUser, $wgContLang;
3241
3242                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3243                 if ( $reason ) {
3244                         $comment .= wfMsgExt( 'colon-separator',
3245                                 array( 'escapenoentities', 'content' ) );
3246                         $comment .= $reason;
3247                 }
3248                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3249                 $comment = $wgContLang->truncate( $comment, 250 );
3250
3251                 $newid = $nt->getArticleID();
3252                 $oldid = $this->getArticleID();
3253                 $latest = $this->getLatestRevId();
3254
3255                 $dbw = wfGetDB( DB_MASTER );
3256                 $now = $dbw->timestamp();
3257
3258                 # Save a null revision in the page's history notifying of the move
3259                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3260                 if ( !is_object( $nullRevision ) ) {
3261                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3262                 }
3263                 $nullRevId = $nullRevision->insertOn( $dbw );
3264
3265                 $article = new Article( $this );
3266                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3267
3268                 # Rename page entry
3269                 $dbw->update( 'page',
3270                         /* SET */ array(
3271                                 'page_touched'   => $now,
3272                                 'page_namespace' => $nt->getNamespace(),
3273                                 'page_title'     => $nt->getDBkey(),
3274                                 'page_latest'    => $nullRevId,
3275                         ),
3276                         /* WHERE */ array( 'page_id' => $oldid ),
3277                         __METHOD__
3278                 );
3279                 $nt->resetArticleID( $oldid );
3280
3281                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3282                         # Insert redirect
3283                         $mwRedir = MagicWord::get( 'redirect' );
3284                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3285                         $redirectArticle = new Article( $this );
3286                         $newid = $redirectArticle->insertOn( $dbw );
3287                         $redirectRevision = new Revision( array(
3288                                 'page'    => $newid,
3289                                 'comment' => $comment,
3290                                 'text'    => $redirectText ) );
3291                         $redirectRevision->insertOn( $dbw );
3292                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3293
3294                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3295
3296                         # Record the just-created redirect's linking to the page
3297                         $dbw->insert( 'pagelinks',
3298                                 array(
3299                                         'pl_from'      => $newid,
3300                                         'pl_namespace' => $nt->getNamespace(),
3301                                         'pl_title'     => $nt->getDBkey() ),
3302                                 __METHOD__ );
3303                         $redirectSuppressed = false;
3304                 } else {
3305                         $this->resetArticleID( 0 );
3306                         $redirectSuppressed = true;
3307                 }
3308
3309                 # Log the move
3310                 $log = new LogPage( 'move' );
3311                 $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3312
3313                 # Purge caches as per article creation
3314                 Article::onArticleCreate( $nt );
3315
3316                 # Purge old title from squid
3317                 # The new title, and links to the new title, are purged in Article::onArticleCreate()
3318                 $this->purgeSquid();
3319
3320         }
3321
3322         /**
3323          * Move this page's subpages to be subpages of $nt
3324          *
3325          * @param $nt Title Move target
3326          * @param $auth bool Whether $wgUser's permissions should be checked
3327          * @param $reason string The reason for the move
3328          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
3329          *  Ignored if the user doesn't have the 'suppressredirect' right
3330          * @return mixed array with old page titles as keys, and strings (new page titles) or
3331          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
3332          */
3333         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3334                 global $wgMaximumMovedPages;
3335                 // Check permissions
3336                 if ( !$this->userCan( 'move-subpages' ) )
3337                         return array( 'cant-move-subpages' );
3338                 // Do the source and target namespaces support subpages?
3339                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) )
3340                         return array( 'namespace-nosubpages',
3341                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3342                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) )
3343                         return array( 'namespace-nosubpages',
3344                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3345
3346                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3347                 $retval = array();
3348                 $count = 0;
3349                 foreach ( $subpages as $oldSubpage ) {
3350                         $count++;
3351                         if ( $count > $wgMaximumMovedPages ) {
3352                                 $retval[$oldSubpage->getPrefixedTitle()] =
3353                                                 array( 'movepage-max-pages',
3354                                                         $wgMaximumMovedPages );
3355                                 break;
3356                         }
3357
3358                         // We don't know whether this function was called before
3359                         // or after moving the root page, so check both
3360                         // $this and $nt
3361                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3362                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3363                                 // When moving a page to a subpage of itself,
3364                                 // don't move it twice
3365                                 continue;
3366                         $newPageName = preg_replace(
3367                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3368                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3369                                         $oldSubpage->getDBkey() );
3370                         if ( $oldSubpage->isTalkPage() ) {
3371                                 $newNs = $nt->getTalkPage()->getNamespace();
3372                         } else {
3373                                 $newNs = $nt->getSubjectPage()->getNamespace();
3374                         }
3375                         # Bug 14385: we need makeTitleSafe because the new page names may
3376                         # be longer than 255 characters.
3377                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3378
3379                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3380                         if ( $success === true ) {
3381                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3382                         } else {
3383                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3384                         }
3385                 }
3386                 return $retval;
3387         }
3388
3389         /**
3390          * Checks if this page is just a one-rev redirect.
3391          * Adds lock, so don't use just for light purposes.
3392          *
3393          * @return \type{\bool}
3394          */
3395         public function isSingleRevRedirect() {
3396                 $dbw = wfGetDB( DB_MASTER );
3397                 # Is it a redirect?
3398                 $row = $dbw->selectRow( 'page',
3399                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3400                         $this->pageCond(),
3401                         __METHOD__,
3402                         array( 'FOR UPDATE' )
3403                 );
3404                 # Cache some fields we may want
3405                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3406                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3407                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3408                 if ( !$this->mRedirect ) {
3409                         return false;
3410                 }
3411                 # Does the article have a history?
3412                 $row = $dbw->selectField( array( 'page', 'revision' ),
3413                         'rev_id',
3414                         array( 'page_namespace' => $this->getNamespace(),
3415                                 'page_title' => $this->getDBkey(),
3416                                 'page_id=rev_page',
3417                                 'page_latest != rev_id'
3418                         ),
3419                         __METHOD__,
3420                         array( 'FOR UPDATE' )
3421                 );
3422                 # Return true if there was no history
3423                 return ( $row === false );
3424         }
3425
3426         /**
3427          * Checks if $this can be moved to a given Title
3428          * - Selects for update, so don't call it unless you mean business
3429          *
3430          * @param $nt \type{Title} the new title to check
3431          * @return \type{\bool} TRUE or FALSE
3432          */
3433         public function isValidMoveTarget( $nt ) {
3434                 $dbw = wfGetDB( DB_MASTER );
3435                 # Is it an existing file?
3436                 if ( $nt->getNamespace() == NS_FILE ) {
3437                         $file = wfLocalFile( $nt );
3438                         if ( $file->exists() ) {
3439                                 wfDebug( __METHOD__ . ": file exists\n" );
3440                                 return false;
3441                         }
3442                 }
3443                 # Is it a redirect with no history?
3444                 if ( !$nt->isSingleRevRedirect() ) {
3445                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3446                         return false;
3447                 }
3448                 # Get the article text
3449                 $rev = Revision::newFromTitle( $nt );
3450                 $text = $rev->getText();
3451                 # Does the redirect point to the source?
3452                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3453                 $m = array();
3454                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3455                         $redirTitle = Title::newFromText( $m[1] );
3456                         if ( !is_object( $redirTitle ) ||
3457                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3458                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3459                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3460                                 return false;
3461                         }
3462                 } else {
3463                         # Fail safe
3464                         wfDebug( __METHOD__ . ": failsafe\n" );
3465                         return false;
3466                 }
3467                 return true;
3468         }
3469
3470         /**
3471          * Can this title be added to a user's watchlist?
3472          *
3473          * @return \type{\bool} TRUE or FALSE
3474          */
3475         public function isWatchable() {
3476                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3477         }
3478
3479         /**
3480          * Get categories to which this Title belongs and return an array of
3481          * categories' names.
3482          *
3483          * @return \type{\array} array an array of parents in the form:
3484          *      $parent => $currentarticle
3485          */
3486         public function getParentCategories() {
3487                 global $wgContLang;
3488
3489                 $titlekey = $this->getArticleId();
3490                 $dbr = wfGetDB( DB_SLAVE );
3491                 $categorylinks = $dbr->tableName( 'categorylinks' );
3492
3493                 # NEW SQL
3494                 $sql = "SELECT * FROM $categorylinks"
3495                      . " WHERE cl_from='$titlekey'"
3496                          . " AND cl_from <> '0'"
3497                          . " ORDER BY cl_sortkey";
3498
3499                 $res = $dbr->query( $sql );
3500
3501                 if ( $dbr->numRows( $res ) > 0 ) {
3502                         foreach ( $res as $row )
3503                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3504                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3505                         $dbr->freeResult( $res );
3506                 } else {
3507                         $data = array();
3508                 }
3509                 return $data;
3510         }
3511
3512         /**
3513          * Get a tree of parent categories
3514          *
3515          * @param $children \type{\array} an array with the children in the keys, to check for circular refs
3516          * @return \type{\array} Tree of parent categories
3517          */
3518         public function getParentCategoryTree( $children = array() ) {
3519                 $stack = array();
3520                 $parents = $this->getParentCategories();
3521
3522                 if ( $parents ) {
3523                         foreach ( $parents as $parent => $current ) {
3524                                 if ( array_key_exists( $parent, $children ) ) {
3525                                         # Circular reference
3526                                         $stack[$parent] = array();
3527                                 } else {
3528                                         $nt = Title::newFromText( $parent );
3529                                         if ( $nt ) {
3530                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3531                                         }
3532                                 }
3533                         }
3534                         return $stack;
3535                 } else {
3536                         return array();
3537                 }
3538         }
3539
3540
3541         /**
3542          * Get an associative array for selecting this title from
3543          * the "page" table
3544          *
3545          * @return \type{\array} Selection array
3546          */
3547         public function pageCond() {
3548                 if ( $this->mArticleID > 0 ) {
3549                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3550                         return array( 'page_id' => $this->mArticleID );
3551                 } else {
3552                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3553                 }
3554         }
3555
3556         /**
3557          * Get the revision ID of the previous revision
3558          *
3559          * @param $revId \type{\int} Revision ID. Get the revision that was before this one.
3560          * @param $flags \type{\int} GAID_FOR_UPDATE
3561          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3562          */
3563         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3564                 $db = ( $flags & GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3565                 return $db->selectField( 'revision', 'rev_id',
3566                         array(
3567                                 'rev_page' => $this->getArticleId( $flags ),
3568                                 'rev_id < ' . intval( $revId )
3569                         ),
3570                         __METHOD__,
3571                         array( 'ORDER BY' => 'rev_id DESC' )
3572                 );
3573         }
3574
3575         /**
3576          * Get the revision ID of the next revision
3577          *
3578          * @param $revId \type{\int} Revision ID. Get the revision that was after this one.
3579          * @param $flags \type{\int} GAID_FOR_UPDATE
3580          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3581          */
3582         public function getNextRevisionID( $revId, $flags = 0 ) {
3583                 $db = ( $flags & GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3584                 return $db->selectField( 'revision', 'rev_id',
3585                         array(
3586                                 'rev_page' => $this->getArticleId( $flags ),
3587                                 'rev_id > ' . intval( $revId )
3588                         ),
3589                         __METHOD__,
3590                         array( 'ORDER BY' => 'rev_id' )
3591                 );
3592         }
3593
3594         /**
3595          * Get the first revision of the page
3596          *
3597          * @param $flags \type{\int} GAID_FOR_UPDATE
3598          * @return Revision (or NULL if page doesn't exist)
3599          */
3600         public function getFirstRevision( $flags = 0 ) {
3601                 $db = ( $flags & GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3602                 $pageId = $this->getArticleId( $flags );
3603                 if ( !$pageId ) return null;
3604                 $row = $db->selectRow( 'revision', '*',
3605                         array( 'rev_page' => $pageId ),
3606                         __METHOD__,
3607                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3608                 );
3609                 if ( !$row ) {
3610                         return null;
3611                 } else {
3612                         return new Revision( $row );
3613                 }
3614         }
3615
3616         /**
3617          * Check if this is a new page
3618          *
3619          * @return bool
3620          */
3621         public function isNewPage() {
3622                 $dbr = wfGetDB( DB_SLAVE );
3623                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3624         }
3625
3626         /**
3627          * Get the oldest revision timestamp of this page
3628          *
3629          * @return String: MW timestamp
3630          */
3631         public function getEarliestRevTime() {
3632                 $dbr = wfGetDB( DB_SLAVE );
3633                 if ( $this->exists() ) {
3634                         $min = $dbr->selectField( 'revision',
3635                                 'MIN(rev_timestamp)',
3636                                 array( 'rev_page' => $this->getArticleId() ),
3637                                 __METHOD__ );
3638                         return wfTimestampOrNull( TS_MW, $min );
3639                 }
3640                 return null;
3641         }
3642
3643         /**
3644          * Get the number of revisions between the given revision IDs.
3645          * Used for diffs and other things that really need it.
3646          *
3647          * @param $old \type{\int} Revision ID.
3648          * @param $new \type{\int} Revision ID.
3649          * @return \type{\int} Number of revisions between these IDs.
3650          */
3651         public function countRevisionsBetween( $old, $new ) {
3652                 $dbr = wfGetDB( DB_SLAVE );
3653                 return (int)$dbr->selectField( 'revision', 'count(*)',
3654                         'rev_page = ' . intval( $this->getArticleId() ) .
3655                         ' AND rev_id > ' . intval( $old ) .
3656                         ' AND rev_id < ' . intval( $new ),
3657                         __METHOD__
3658                 );
3659         }
3660
3661         /**
3662          * Compare with another title.
3663          *
3664          * @param $title \type{Title}
3665          * @return \type{\bool} TRUE or FALSE
3666          */
3667         public function equals( Title $title ) {
3668                 // Note: === is necessary for proper matching of number-like titles.
3669                 return $this->getInterwiki() === $title->getInterwiki()
3670                         && $this->getNamespace() == $title->getNamespace()
3671                         && $this->getDBkey() === $title->getDBkey();
3672         }
3673
3674         /**
3675          * Callback for usort() to do title sorts by (namespace, title)
3676          *
3677          * @return Integer: result of string comparison, or namespace comparison
3678          */
3679         public static function compare( $a, $b ) {
3680                 if ( $a->getNamespace() == $b->getNamespace() ) {
3681                         return strcmp( $a->getText(), $b->getText() );
3682                 } else {
3683                         return $a->getNamespace() - $b->getNamespace();
3684                 }
3685         }
3686
3687         /**
3688          * Return a string representation of this title
3689          *
3690          * @return \type{\string} String representation of this title
3691          */
3692         public function __toString() {
3693                 return $this->getPrefixedText();
3694         }
3695
3696         /**
3697          * Check if page exists.  For historical reasons, this function simply
3698          * checks for the existence of the title in the page table, and will
3699          * thus return false for interwiki links, special pages and the like.
3700          * If you want to know if a title can be meaningfully viewed, you should
3701          * probably call the isKnown() method instead.
3702          *
3703          * @return \type{\bool}
3704          */
3705         public function exists() {
3706                 return $this->getArticleId() != 0;
3707         }
3708
3709         /**
3710          * Should links to this title be shown as potentially viewable (i.e. as
3711          * "bluelinks"), even if there's no record by this title in the page
3712          * table?
3713          *
3714          * This function is semi-deprecated for public use, as well as somewhat
3715          * misleadingly named.  You probably just want to call isKnown(), which
3716          * calls this function internally.
3717          *
3718          * (ISSUE: Most of these checks are cheap, but the file existence check
3719          * can potentially be quite expensive.  Including it here fixes a lot of
3720          * existing code, but we might want to add an optional parameter to skip
3721          * it and any other expensive checks.)
3722          *
3723          * @return \type{\bool}
3724          */
3725         public function isAlwaysKnown() {
3726                 if ( $this->mInterwiki != '' ) {
3727                         return true;  // any interwiki link might be viewable, for all we know
3728                 }
3729                 switch( $this->mNamespace ) {
3730                 case NS_MEDIA:
3731                 case NS_FILE:
3732                         return (bool)wfFindFile( $this );  // file exists, possibly in a foreign repo
3733                 case NS_SPECIAL:
3734                         return SpecialPage::exists( $this->getDBkey() );  // valid special page
3735                 case NS_MAIN:
3736                         return $this->mDbkeyform == '';  // selflink, possibly with fragment
3737                 case NS_MEDIAWIKI:
3738                         // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3739                         // the full l10n of that language to be loaded. That takes much memory and
3740                         // isn't needed. So we strip the language part away.
3741                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3742                         return (bool)wfMsgWeirdKey( $basename );  // known system message
3743                 default:
3744                         return false;
3745                 }
3746         }
3747
3748         /**
3749          * Does this title refer to a page that can (or might) be meaningfully
3750          * viewed?  In particular, this function may be used to determine if
3751          * links to the title should be rendered as "bluelinks" (as opposed to
3752          * "redlinks" to non-existent pages).
3753          *
3754          * @return \type{\bool}
3755          */
3756         public function isKnown() {
3757                 return $this->exists() || $this->isAlwaysKnown();
3758         }
3759
3760         /**
3761          * Does this page have source text?
3762          *
3763          * @return Boolean
3764          */
3765         public function hasSourceText() {
3766                 if ( $this->exists() )
3767                         return true;
3768
3769                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3770                         // If the page doesn't exist but is a known system message, default
3771                         // message content will be displayed, same for language subpages
3772                         // Also, if the page is form Mediawiki:message/lang, calling wfMsgWeirdKey
3773                         // causes the full l10n of that language to be loaded. That takes much
3774                         // memory and isn't needed. So we strip the language part away.
3775                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3776                         return (bool)wfMsgWeirdKey( $basename );
3777                 }
3778
3779                 return false;
3780         }
3781
3782         /**
3783         * Is this in a namespace that allows actual pages?
3784         *
3785         * @return \type{\bool}
3786         * @internal note -- uses hardcoded namespace index instead of constants
3787         */
3788         public function canExist() {
3789                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3790         }
3791
3792         /**
3793          * Update page_touched timestamps and send squid purge messages for
3794          * pages linking to this title. May be sent to the job queue depending
3795          * on the number of links. Typically called on create and delete.
3796          */
3797         public function touchLinks() {
3798                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3799                 $u->doUpdate();
3800
3801                 if ( $this->getNamespace() == NS_CATEGORY ) {
3802                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3803                         $u->doUpdate();
3804                 }
3805         }
3806
3807         /**
3808          * Get the last touched timestamp
3809          *
3810          * @param $db DatabaseBase: optional db
3811          * @return \type{\string} Last touched timestamp
3812          */
3813         public function getTouched( $db = null ) {
3814                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3815                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3816                 return $touched;
3817         }
3818
3819         /**
3820          * Get the timestamp when this page was updated since the user last saw it.
3821          *
3822          * @param $user User
3823          * @return Mixed: string/null
3824          */
3825         public function getNotificationTimestamp( $user = null ) {
3826                 global $wgUser, $wgShowUpdatedMarker;
3827                 // Assume current user if none given
3828                 if ( !$user ) $user = $wgUser;
3829                 // Check cache first
3830                 $uid = $user->getId();
3831                 if ( isset( $this->mNotificationTimestamp[$uid] ) ) {
3832                         return $this->mNotificationTimestamp[$uid];
3833                 }
3834                 if ( !$uid || !$wgShowUpdatedMarker ) {
3835                         return $this->mNotificationTimestamp[$uid] = false;
3836                 }
3837                 // Don't cache too much!
3838                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3839                         $this->mNotificationTimestamp = array();
3840                 }
3841                 $dbr = wfGetDB( DB_SLAVE );
3842                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3843                         'wl_notificationtimestamp',
3844                         array( 'wl_namespace' => $this->getNamespace(),
3845                                 'wl_title' => $this->getDBkey(),
3846                                 'wl_user' => $user->getId()
3847                         ),
3848                         __METHOD__
3849                 );
3850                 return $this->mNotificationTimestamp[$uid];
3851         }
3852
3853         /**
3854          * Get the trackback URL for this page
3855          *
3856          * @return \type{\string} Trackback URL
3857          */
3858         public function trackbackURL() {
3859                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3860
3861                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3862                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3863         }
3864
3865         /**
3866          * Get the trackback RDF for this page
3867          *
3868          * @return \type{\string} Trackback RDF
3869          */
3870         public function trackbackRDF() {
3871                 $url = htmlspecialchars( $this->getFullURL() );
3872                 $title = htmlspecialchars( $this->getText() );
3873                 $tburl = $this->trackbackURL();
3874
3875                 // Autodiscovery RDF is placed in comments so HTML validator
3876                 // won't barf. This is a rather icky workaround, but seems
3877                 // frequently used by this kind of RDF thingy.
3878                 //
3879                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3880                 return "<!--
3881 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3882          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3883          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3884 <rdf:Description
3885    rdf:about=\"$url\"
3886    dc:identifier=\"$url\"
3887    dc:title=\"$title\"
3888    trackback:ping=\"$tburl\" />
3889 </rdf:RDF>
3890 -->";
3891         }
3892
3893         /**
3894          * Generate strings used for xml 'id' names in monobook tabs
3895          *
3896          * @param $prepend string defaults to 'nstab-'
3897          * @return \type{\string} XML 'id' name
3898          */
3899         public function getNamespaceKey( $prepend = 'nstab-' ) {
3900                 global $wgContLang;
3901                 // Gets the subject namespace if this title
3902                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
3903                 // Checks if cononical namespace name exists for namespace
3904                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
3905                         // Uses canonical namespace name
3906                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
3907                 } else {
3908                         // Uses text of namespace
3909                         $namespaceKey = $this->getSubjectNsText();
3910                 }
3911                 // Makes namespace key lowercase
3912                 $namespaceKey = $wgContLang->lc( $namespaceKey );
3913                 // Uses main
3914                 if ( $namespaceKey == '' ) {
3915                         $namespaceKey = 'main';
3916                 }
3917                 // Changes file to image for backwards compatibility
3918                 if ( $namespaceKey == 'file' ) {
3919                         $namespaceKey = 'image';
3920                 }
3921                 return $prepend . $namespaceKey;
3922         }
3923
3924         /**
3925          * Returns true if this is a special page.
3926          *
3927          * @return boolean
3928          */
3929         public function isSpecialPage( ) {
3930                 return $this->getNamespace() == NS_SPECIAL;
3931         }
3932
3933         /**
3934          * Returns true if this title resolves to the named special page
3935          *
3936          * @param $name \type{\string} The special page name
3937          * @return boolean
3938          */
3939         public function isSpecial( $name ) {
3940                 if ( $this->getNamespace() == NS_SPECIAL ) {
3941                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
3942                         if ( $name == $thisName ) {
3943                                 return true;
3944                         }
3945                 }
3946                 return false;
3947         }
3948
3949         /**
3950          * If the Title refers to a special page alias which is not the local default,
3951          *
3952          * @return \type{Title} A new Title which points to the local default.
3953          *         Otherwise, returns $this.
3954          */
3955         public function fixSpecialName() {
3956                 if ( $this->getNamespace() == NS_SPECIAL ) {
3957                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
3958                         if ( $canonicalName ) {
3959                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
3960                                 if ( $localName != $this->mDbkeyform ) {
3961                                         return Title::makeTitle( NS_SPECIAL, $localName );
3962                                 }
3963                         }
3964                 }
3965                 return $this;
3966         }
3967
3968         /**
3969          * Is this Title in a namespace which contains content?
3970          * In other words, is this a content page, for the purposes of calculating
3971          * statistics, etc?
3972          *
3973          * @return \type{\bool}
3974          */
3975         public function isContentPage() {
3976                 return MWNamespace::isContent( $this->getNamespace() );
3977         }
3978
3979         /**
3980          * Get all extant redirects to this Title
3981          *
3982          * @param $ns \twotypes{\int,\null} Single namespace to consider;
3983          *            NULL to consider all namespaces
3984          * @return \type{\arrayof{Title}} Redirects to this title
3985          */
3986         public function getRedirectsHere( $ns = null ) {
3987                 $redirs = array();
3988
3989                 $dbr = wfGetDB( DB_SLAVE );
3990                 $where = array(
3991                         'rd_namespace' => $this->getNamespace(),
3992                         'rd_title' => $this->getDBkey(),
3993                         'rd_from = page_id'
3994                 );
3995                 if ( !is_null( $ns ) ) $where['page_namespace'] = $ns;
3996
3997                 $res = $dbr->select(
3998                         array( 'redirect', 'page' ),
3999                         array( 'page_namespace', 'page_title' ),
4000                         $where,
4001                         __METHOD__
4002                 );
4003
4004
4005                 foreach ( $res as $row ) {
4006                         $redirs[] = self::newFromRow( $row );
4007                 }
4008                 return $redirs;
4009         }
4010
4011         /**
4012          * Check if this Title is a valid redirect target
4013          *
4014          * @return \type{\bool}
4015          */
4016         public function isValidRedirectTarget() {
4017                 global $wgInvalidRedirectTargets;
4018
4019                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4020                 if ( $this->isSpecial( 'Userlogout' ) ) {
4021                         return false;
4022                 }
4023
4024                 foreach ( $wgInvalidRedirectTargets as $target ) {
4025                         if ( $this->isSpecial( $target ) ) {
4026                                 return false;
4027                         }
4028                 }
4029
4030                 return true;
4031         }
4032
4033         /**
4034          * Get a backlink cache object
4035          *
4036          * @return object BacklinkCache
4037          */
4038         function getBacklinkCache() {
4039                 if ( is_null( $this->mBacklinkCache ) ) {
4040                         $this->mBacklinkCache = new BacklinkCache( $this );
4041                 }
4042                 return $this->mBacklinkCache;
4043         }
4044
4045         /**
4046          * Whether the magic words __INDEX__ and __NOINDEX__ function for
4047          * this page.
4048          *
4049          * @return Boolean
4050          */
4051         public function canUseNoindex() {
4052                 global $wgContentNamespaces,  $wgExemptFromUserRobotsControl;
4053
4054                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4055                         ? $wgContentNamespaces
4056                         : $wgExemptFromUserRobotsControl;
4057
4058                 return !in_array( $this->mNamespace, $bannedNamespaces );
4059
4060         }
4061
4062         /**
4063          * Returns restriction types for the current Title
4064          *
4065          * @return array applicable restriction types
4066          */
4067         public function getRestrictionTypes() {
4068                 global $wgRestrictionTypes;
4069                 $types = $this->exists() ? $wgRestrictionTypes : array( 'create' );
4070
4071                 if ( $this->getNamespace() == NS_FILE ) {
4072                         $types[] = 'upload';
4073                 }
4074
4075                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4076
4077                 return $types;
4078         }
4079 }