includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  * @file
   5  */
   6
   7 /**
   8  * @deprecated This used to be a define, but was moved to
   9  * Title::GAID_FOR_UPDATE in 1.17. This will probably be removed in 1.18
  10  */
  11 define( 'GAID_FOR_UPDATE', Title::GAID_FOR_UPDATE );
  12
  13 /**
  14  * Represents a title within MediaWiki.
  15  * Optionally may contain an interwiki designation or namespace.
  16  * @note This class can fetch various kinds of data from the database;
  17  *       however, it does so inefficiently.
  18  *
  19  * @internal documentation reviewed 15 Mar 2010
  20  */
  21 class Title {
  22         /** @name Static cache variables */
  23         // @{
  24         static private $titleCache = array();
  25         // @}
  26
  27         /**
  28          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  29          * commonly used titles. On a batch operation this can become a memory leak
  30          * if not bounded. After hitting this many titles reset the cache.
  31          */
  32         const CACHE_MAX = 1000;
  33
  34         /**
  35          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  36          * to use the master DB
  37          */
  38         const GAID_FOR_UPDATE = 1;
  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 for getTitleProtection (create protection)
  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 String the database key, which has underscores
  89          *      instead of spaces, possibly including namespace and
  90          *      interwiki prefixes
  91          * @return Title, 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         /**
 104          * Create a new Title from text, such as what one would find in a link. De-
 105          * codes any HTML entities in the text.
 106          *
 107          * @param $text String the link text; spaces, prefixes, and an
 108          *   initial ':' indicating the main namespace are accepted.
 109          * @param $defaultNamespace Int the namespace to use if none is speci-
 110          *   fied by a prefix.  If you want to force a specific namespace even if
 111          *   $text might begin with a namespace prefix, use makeTitle() or
 112          *   makeTitleSafe().
 113          * @return Title, or null on an error.
 114          */
 115         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 116                 if ( is_object( $text ) ) {
 117                         throw new MWException( 'Title::newFromText given an object' );
 118                 }
 119
 120                 /**
 121                  * Wiki pages often contain multiple links to the same page.
 122                  * Title normalization and parsing can become expensive on
 123                  * pages with many links, so we can save a little time by
 124                  * caching them.
 125                  *
 126                  * In theory these are value objects and won't get changed...
 127                  */
 128                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 129                         return Title::$titleCache[$text];
 130                 }
 131
 132                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 133                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 134
 135                 $t = new Title();
 136                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 137                 $t->mDefaultNamespace = $defaultNamespace;
 138
 139                 static $cachedcount = 0 ;
 140                 if ( $t->secureAndSplit() ) {
 141                         if ( $defaultNamespace == NS_MAIN ) {
 142                                 if ( $cachedcount >= self::CACHE_MAX ) {
 143                                         # Avoid memory leaks on mass operations...
 144                                         Title::$titleCache = array();
 145                                         $cachedcount = 0;
 146                                 }
 147                                 $cachedcount++;
 148                                 Title::$titleCache[$text] =& $t;
 149                         }
 150                         return $t;
 151                 } else {
 152                         $ret = null;
 153                         return $ret;
 154                 }
 155         }
 156
 157         /**
 158          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 159          *
 160          * Example of wrong and broken code:
 161          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 162          *
 163          * Example of right code:
 164          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 165          *
 166          * Create a new Title from URL-encoded text. Ensures that
 167          * the given title's length does not exceed the maximum.
 168          *
 169          * @param $url String the title, as might be taken from a URL
 170          * @return Title the new object, or NULL on an error
 171          */
 172         public static function newFromURL( $url ) {
 173                 global $wgLegalTitleChars;
 174                 $t = new Title();
 175
 176                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 177                 # but some URLs used it as a space replacement and they still come
 178                 # from some external search tools.
 179                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 180                         $url = str_replace( '+', ' ', $url );
 181                 }
 182
 183                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 184                 if ( $t->secureAndSplit() ) {
 185                         return $t;
 186                 } else {
 187                         return null;
 188                 }
 189         }
 190
 191         /**
 192          * Create a new Title from an article ID
 193          *
 194          * @param $id Int the page_id corresponding to the Title to create
 195          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 196          * @return Title the new object, or NULL on an error
 197          */
 198         public static function newFromID( $id, $flags = 0 ) {
 199                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 200                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 201                 if ( $row !== false ) {
 202                         $title = Title::newFromRow( $row );
 203                 } else {
 204                         $title = null;
 205                 }
 206                 return $title;
 207         }
 208
 209         /**
 210          * Make an array of titles from an array of IDs
 211          *
 212          * @param $ids Array of Int Array of IDs
 213          * @return Array of Titles
 214          */
 215         public static function newFromIDs( $ids ) {
 216                 if ( !count( $ids ) ) {
 217                         return array();
 218                 }
 219                 $dbr = wfGetDB( DB_SLAVE );
 220
 221                 $res = $dbr->select(
 222                         'page',
 223                         array(
 224                                 'page_namespace', 'page_title', 'page_id',
 225                                 'page_len', 'page_is_redirect', 'page_latest',
 226                         ),
 227                         array( 'page_id' => $ids ),
 228                         __METHOD__
 229                 );
 230
 231                 $titles = array();
 232                 foreach ( $res as $row ) {
 233                         $titles[] = Title::newFromRow( $row );
 234                 }
 235                 return $titles;
 236         }
 237
 238         /**
 239          * Make a Title object from a DB row
 240          *
 241          * @param $row Object database row (needs at least page_title,page_namespace)
 242          * @return Title corresponding Title
 243          */
 244         public static function newFromRow( $row ) {
 245                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 246
 247                 $t->mArticleID = isset( $row->page_id ) ? intval( $row->page_id ) : -1;
 248                 $t->mLength = isset( $row->page_len ) ? intval( $row->page_len ) : -1;
 249                 $t->mRedirect = isset( $row->page_is_redirect ) ? (bool)$row->page_is_redirect : null;
 250                 $t->mLatestID = isset( $row->page_latest ) ? intval( $row->page_latest ) : false;
 251
 252                 return $t;
 253         }
 254
 255         /**
 256          * Create a new Title from a namespace index and a DB key.
 257          * It's assumed that $ns and $title are *valid*, for instance when
 258          * they came directly from the database or a special page name.
 259          * For convenience, spaces are converted to underscores so that
 260          * eg user_text fields can be used directly.
 261          *
 262          * @param $ns Int the namespace of the article
 263          * @param $title String the unprefixed database key form
 264          * @param $fragment String the link fragment (after the "#")
 265          * @param $interwiki String the interwiki prefix
 266          * @return Title the new object
 267          */
 268         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 269                 $t = new Title();
 270                 $t->mInterwiki = $interwiki;
 271                 $t->mFragment = $fragment;
 272                 $t->mNamespace = $ns = intval( $ns );
 273                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 274                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 275                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 276                 $t->mTextform = str_replace( '_', ' ', $title );
 277                 return $t;
 278         }
 279
 280         /**
 281          * Create a new Title from a namespace index and a DB key.
 282          * The parameters will be checked for validity, which is a bit slower
 283          * than makeTitle() but safer for user-provided data.
 284          *
 285          * @param $ns Int the namespace of the article
 286          * @param $title String database key form
 287          * @param $fragment String the link fragment (after the "#")
 288          * @param $interwiki String interwiki prefix
 289          * @return Title the new object, or NULL on an error
 290          */
 291         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 292                 $t = new Title();
 293                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 294                 if ( $t->secureAndSplit() ) {
 295                         return $t;
 296                 } else {
 297                         return null;
 298                 }
 299         }
 300
 301         /**
 302          * Create a new Title for the Main Page
 303          *
 304          * @return Title the new object
 305          */
 306         public static function newMainPage() {
 307                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 308                 // Don't give fatal errors if the message is broken
 309                 if ( !$title ) {
 310                         $title = Title::newFromText( 'Main Page' );
 311                 }
 312                 return $title;
 313         }
 314
 315         /**
 316          * Extract a redirect destination from a string and return the
 317          * Title, or null if the text doesn't contain a valid redirect
 318          * This will only return the very next target, useful for
 319          * the redirect table and other checks that don't need full recursion
 320          *
 321          * @param $text String: Text with possible redirect
 322          * @return Title: The corresponding Title
 323          */
 324         public static function newFromRedirect( $text ) {
 325                 return self::newFromRedirectInternal( $text );
 326         }
 327
 328         /**
 329          * Extract a redirect destination from a string and return the
 330          * Title, or null if the text doesn't contain a valid redirect
 331          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 332          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 333          *
 334          * @param $text String Text with possible redirect
 335          * @return Title
 336          */
 337         public static function newFromRedirectRecurse( $text ) {
 338                 $titles = self::newFromRedirectArray( $text );
 339                 return $titles ? array_pop( $titles ) : null;
 340         }
 341
 342         /**
 343          * Extract a redirect destination from a string and return an
 344          * array of Titles, or null if the text doesn't contain a valid redirect
 345          * The last element in the array is the final destination after all redirects
 346          * have been resolved (up to $wgMaxRedirects times)
 347          *
 348          * @param $text String Text with possible redirect
 349          * @return Array of Titles, with the destination last
 350          */
 351         public static function newFromRedirectArray( $text ) {
 352                 global $wgMaxRedirects;
 353                 $title = self::newFromRedirectInternal( $text );
 354                 if ( is_null( $title ) ) {
 355                         return null;
 356                 }
 357                 // recursive check to follow double redirects
 358                 $recurse = $wgMaxRedirects;
 359                 $titles = array( $title );
 360                 while ( --$recurse > 0 ) {
 361                         if ( $title->isRedirect() ) {
 362                                 $article = new Article( $title, 0 );
 363                                 $newtitle = $article->getRedirectTarget();
 364                         } else {
 365                                 break;
 366                         }
 367                         // Redirects to some special pages are not permitted
 368                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 369                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 370                                 $title = $newtitle;
 371                                 $titles[] = $newtitle;
 372                         } else {
 373                                 break;
 374                         }
 375                 }
 376                 return $titles;
 377         }
 378
 379         /**
 380          * Really extract the redirect destination
 381          * Do not call this function directly, use one of the newFromRedirect* functions above
 382          *
 383          * @param $text String Text with possible redirect
 384          * @return Title
 385          */
 386         protected static function newFromRedirectInternal( $text ) {
 387                 global $wgMaxRedirects;
 388                 if ( $wgMaxRedirects < 1 ) {
 389                         //redirects are disabled, so quit early
 390                         return null;
 391                 }
 392                 $redir = MagicWord::get( 'redirect' );
 393                 $text = trim( $text );
 394                 if ( $redir->matchStartAndRemove( $text ) ) {
 395                         // Extract the first link and see if it's usable
 396                         // Ensure that it really does come directly after #REDIRECT
 397                         // Some older redirects included a colon, so don't freak about that!
 398                         $m = array();
 399                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 400                                 // Strip preceding colon used to "escape" categories, etc.
 401                                 // and URL-decode links
 402                                 if ( strpos( $m[1], '%' ) !== false ) {
 403                                         // Match behavior of inline link parsing here;
 404                                         $m[1] = rawurldecode( 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 Int the page_id of the article
 425          * @return Title an object representing the article, or NULL if no such article was found
 426          */
 427         public static function nameOf( $id ) {
 428                 $dbr = wfGetDB( DB_SLAVE );
 429
 430                 $s = $dbr->selectRow(
 431                         'page',
 432                         array( 'page_namespace', 'page_title' ),
 433                         array( 'page_id' => $id ),
 434                         __METHOD__
 435                 );
 436                 if ( $s === false ) {
 437                         return null;
 438                 }
 439
 440                 $n = self::makeName( $s->page_namespace, $s->page_title );
 441                 return $n;
 442         }
 443
 444         /**
 445          * Get a regex character class describing the legal characters in a link
 446          *
 447          * @return String the list of characters, not delimited
 448          */
 449         public static function legalChars() {
 450                 global $wgLegalTitleChars;
 451                 return $wgLegalTitleChars;
 452         }
 453
 454         /**
 455          * Get a string representation of a title suitable for
 456          * including in a search index
 457          *
 458          * @param $ns Int a namespace index
 459          * @param $title String text-form main part
 460          * @return String a stripped-down title string ready for the search index
 461          */
 462         public static function indexTitle( $ns, $title ) {
 463                 global $wgContLang;
 464
 465                 $lc = SearchEngine::legalSearchChars() . '&#;';
 466                 $t = $wgContLang->normalizeForSearch( $title );
 467                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 468                 $t = $wgContLang->lc( $t );
 469
 470                 # Handle 's, s'
 471                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 472                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 473
 474                 $t = preg_replace( "/\\s+/", ' ', $t );
 475
 476                 if ( $ns == NS_FILE ) {
 477                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 478                 }
 479                 return trim( $t );
 480         }
 481
 482         /**
 483          * Make a prefixed DB key from a DB key and a namespace index
 484          *
 485          * @param $ns Int numerical representation of the namespace
 486          * @param $title String the DB key form the title
 487          * @param $fragment String The link fragment (after the "#")
 488          * @param $interwiki String The interwiki prefix
 489          * @return String the prefixed form of the title
 490          */
 491         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 492                 global $wgContLang;
 493
 494                 $namespace = $wgContLang->getNsText( $ns );
 495                 $name = $namespace == '' ? $title : "$namespace:$title";
 496                 if ( strval( $interwiki ) != '' ) {
 497                         $name = "$interwiki:$name";
 498                 }
 499                 if ( strval( $fragment ) != '' ) {
 500                         $name .= '#' . $fragment;
 501                 }
 502                 return $name;
 503         }
 504
 505         /**
 506          * Determine whether the object refers to a page within
 507          * this project.
 508          *
 509          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 510          */
 511         public function isLocal() {
 512                 if ( $this->mInterwiki != '' ) {
 513                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 514                 } else {
 515                         return true;
 516                 }
 517         }
 518
 519         /**
 520          * Determine whether the object refers to a page within
 521          * this project and is transcludable.
 522          *
 523          * @return Bool TRUE if this is transcludable
 524          */
 525         public function isTrans() {
 526                 if ( $this->mInterwiki == '' ) {
 527                         return false;
 528                 }
 529
 530                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 531         }
 532
 533         /**
 534          * Returns the DB name of the distant wiki which owns the object.
 535          *
 536          * @return String the DB name
 537          */
 538         public function getTransWikiID() {
 539                 if ( $this->mInterwiki == '' ) {
 540                         return false;
 541                 }
 542
 543                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 544         }
 545
 546         /**
 547          * Escape a text fragment, say from a link, for a URL
 548          *
 549          * @param $fragment string containing a URL or link fragment (after the "#")
 550          * @return String: escaped string
 551          */
 552         static function escapeFragmentForURL( $fragment ) {
 553                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 554                 # fragments appear not to work in IE (at least up to 7) or in at least
 555                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 556                 # to care if they aren't encoded.
 557                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 558         }
 559
 560 # ----------------------------------------------------------------------------
 561 #       Other stuff
 562 # ----------------------------------------------------------------------------
 563
 564         /** Simple accessors */
 565         /**
 566          * Get the text form (spaces not underscores) of the main part
 567          *
 568          * @return String Main part of the title
 569          */
 570         public function getText() { return $this->mTextform; }
 571
 572         /**
 573          * Get the URL-encoded form of the main part
 574          *
 575          * @return String Main part of the title, URL-encoded
 576          */
 577         public function getPartialURL() { return $this->mUrlform; }
 578
 579         /**
 580          * Get the main part with underscores
 581          *
 582          * @return String: Main part of the title, with underscores
 583          */
 584         public function getDBkey() { return $this->mDbkeyform; }
 585
 586         /**
 587          * Get the namespace index, i.e. one of the NS_xxxx constants.
 588          *
 589          * @return Integer: Namespace index
 590          */
 591         public function getNamespace() { return $this->mNamespace; }
 592
 593         /**
 594          * Get the namespace text
 595          *
 596          * @return String: Namespace text
 597          */
 598         public function getNsText() {
 599                 global $wgContLang;
 600
 601                 if ( $this->mInterwiki != '' ) {
 602                         // This probably shouldn't even happen. ohh man, oh yuck.
 603                         // But for interwiki transclusion it sometimes does.
 604                         // Shit. Shit shit shit.
 605                         //
 606                         // Use the canonical namespaces if possible to try to
 607                         // resolve a foreign namespace.
 608                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 609                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 610                         }
 611                 }
 612
 613                 if ( $wgContLang->needsGenderDistinction() &&
 614                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 615                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 616                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 617                 }
 618
 619                 return $wgContLang->getNsText( $this->mNamespace );
 620         }
 621
 622         /**
 623          * Get the DB key with the initial letter case as specified by the user
 624          *
 625          * @return String DB key
 626          */
 627         function getUserCaseDBKey() {
 628                 return $this->mUserCaseDBKey;
 629         }
 630
 631         /**
 632          * Get the namespace text of the subject (rather than talk) page
 633          *
 634          * @return String Namespace text
 635          */
 636         public function getSubjectNsText() {
 637                 global $wgContLang;
 638                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 639         }
 640
 641         /**
 642          * Get the namespace text of the talk page
 643          *
 644          * @return String Namespace text
 645          */
 646         public function getTalkNsText() {
 647                 global $wgContLang;
 648                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 649         }
 650
 651         /**
 652          * Could this title have a corresponding talk page?
 653          *
 654          * @return Bool TRUE or FALSE
 655          */
 656         public function canTalk() {
 657                 return( MWNamespace::canTalk( $this->mNamespace ) );
 658         }
 659
 660         /**
 661          * Get the interwiki prefix (or null string)
 662          *
 663          * @return String Interwiki prefix
 664          */
 665         public function getInterwiki() { return $this->mInterwiki; }
 666
 667         /**
 668          * Get the Title fragment (i.e.\ the bit after the #) in text form
 669          *
 670          * @return String Title fragment
 671          */
 672         public function getFragment() { return $this->mFragment; }
 673
 674         /**
 675          * Get the fragment in URL form, including the "#" character if there is one
 676          * @return String Fragment in URL form
 677          */
 678         public function getFragmentForURL() {
 679                 if ( $this->mFragment == '' ) {
 680                         return '';
 681                 } else {
 682                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 683                 }
 684         }
 685
 686         /**
 687          * Get the default namespace index, for when there is no namespace
 688          *
 689          * @return Int Default namespace index
 690          */
 691         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 692
 693         /**
 694          * Get title for search index
 695          *
 696          * @return String a stripped-down title string ready for the
 697          *  search index
 698          */
 699         public function getIndexTitle() {
 700                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 701         }
 702
 703         /**
 704          * Get the prefixed database key form
 705          *
 706          * @return String the prefixed title, with underscores and
 707          *  any interwiki and namespace prefixes
 708          */
 709         public function getPrefixedDBkey() {
 710                 $s = $this->prefix( $this->mDbkeyform );
 711                 $s = str_replace( ' ', '_', $s );
 712                 return $s;
 713         }
 714
 715         /**
 716          * Get the prefixed title with spaces.
 717          * This is the form usually used for display
 718          *
 719          * @return String the prefixed title, with spaces
 720          */
 721         public function getPrefixedText() {
 722                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 723                         $s = $this->prefix( $this->mTextform );
 724                         $s = str_replace( '_', ' ', $s );
 725                         $this->mPrefixedText = $s;
 726                 }
 727                 return $this->mPrefixedText;
 728         }
 729
 730         /**
 731          * Get the prefixed title with spaces, plus any fragment
 732          * (part beginning with '#')
 733          *
 734          * @return String the prefixed title, with spaces and the fragment, including '#'
 735          */
 736         public function getFullText() {
 737                 $text = $this->getPrefixedText();
 738                 if ( $this->mFragment != '' ) {
 739                         $text .= '#' . $this->mFragment;
 740                 }
 741                 return $text;
 742         }
 743
 744         /**
 745          * Get the base name, i.e. the leftmost parts before the /
 746          *
 747          * @return String Base name
 748          */
 749         public function getBaseText() {
 750                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 751                         return $this->getText();
 752                 }
 753
 754                 $parts = explode( '/', $this->getText() );
 755                 # Don't discard the real title if there's no subpage involved
 756                 if ( count( $parts ) > 1 ) {
 757                         unset( $parts[count( $parts ) - 1] );
 758                 }
 759                 return implode( '/', $parts );
 760         }
 761
 762         /**
 763          * Get the lowest-level subpage name, i.e. the rightmost part after /
 764          *
 765          * @return String Subpage name
 766          */
 767         public function getSubpageText() {
 768                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 769                         return( $this->mTextform );
 770                 }
 771                 $parts = explode( '/', $this->mTextform );
 772                 return( $parts[count( $parts ) - 1] );
 773         }
 774
 775         /**
 776          * Get a URL-encoded form of the subpage text
 777          *
 778          * @return String URL-encoded subpage name
 779          */
 780         public function getSubpageUrlForm() {
 781                 $text = $this->getSubpageText();
 782                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 783                 return( $text );
 784         }
 785
 786         /**
 787          * Get a URL-encoded title (not an actual URL) including interwiki
 788          *
 789          * @return String the URL-encoded form
 790          */
 791         public function getPrefixedURL() {
 792                 $s = $this->prefix( $this->mDbkeyform );
 793                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 794                 return $s;
 795         }
 796
 797         /**
 798          * Get a real URL referring to this title, with interwiki link and
 799          * fragment
 800          *
 801          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 802          *   links. Can be specified as an associative array as well, e.g.,
 803          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 804          * @param $variant String language variant of url (for sr, zh..)
 805          * @return String the URL
 806          */
 807         public function getFullURL( $query = '', $variant = false ) {
 808                 global $wgServer, $wgRequest;
 809
 810                 if ( is_array( $query ) ) {
 811                         $query = wfArrayToCGI( $query );
 812                 }
 813
 814                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 815                 if ( !$interwiki ) {
 816                         $url = $this->getLocalURL( $query, $variant );
 817
 818                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 819                         // Correct fix would be to move the prepending elsewhere.
 820                         if ( $wgRequest->getVal( 'action' ) != 'render' ) {
 821                                 $url = $wgServer . $url;
 822                         }
 823                 } else {
 824                         $baseUrl = $interwiki->getURL();
 825
 826                         $namespace = wfUrlencode( $this->getNsText() );
 827                         if ( $namespace != '' ) {
 828                                 # Can this actually happen? Interwikis shouldn't be parsed.
 829                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 830                                 $namespace .= ':';
 831                         }
 832                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 833                         $url = wfAppendQuery( $url, $query );
 834                 }
 835
 836                 # Finally, add the fragment.
 837                 $url .= $this->getFragmentForURL();
 838
 839                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 840                 return $url;
 841         }
 842
 843         /**
 844          * Get a URL with no fragment or server name.  If this page is generated
 845          * with action=render, $wgServer is prepended.
 846          *
 847          * @param $query Mixed: an optional query string; if not specified,
 848          *   $wgArticlePath will be used.  Can be specified as an associative array
 849          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 850          *   URL-escaped).
 851          * @param $variant String language variant of url (for sr, zh..)
 852          * @return String the URL
 853          */
 854         public function getLocalURL( $query = '', $variant = false ) {
 855                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 856                 global $wgVariantArticlePath, $wgContLang;
 857
 858                 if ( is_array( $query ) ) {
 859                         $query = wfArrayToCGI( $query );
 860                 }
 861
 862                 if ( $this->isExternal() ) {
 863                         $url = $this->getFullURL();
 864                         if ( $query ) {
 865                                 // This is currently only used for edit section links in the
 866                                 // context of interwiki transclusion. In theory we should
 867                                 // append the query to the end of any existing query string,
 868                                 // but interwiki transclusion is already broken in that case.
 869                                 $url .= "?$query";
 870                         }
 871                 } else {
 872                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 873                         if ( $query == '' ) {
 874                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 875                                         if ( !$wgVariantArticlePath ) {
 876                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 877                                         } else {
 878                                                 $variantArticlePath = $wgVariantArticlePath;
 879                                         }
 880                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 881                                         $url = str_replace( '$1', $dbkey, $url  );
 882                                 } else {
 883                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 884                                 }
 885                         } else {
 886                                 global $wgActionPaths;
 887                                 $url = false;
 888                                 $matches = array();
 889                                 if ( !empty( $wgActionPaths ) &&
 890                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 891                                 {
 892                                         $action = urldecode( $matches[2] );
 893                                         if ( isset( $wgActionPaths[$action] ) ) {
 894                                                 $query = $matches[1];
 895                                                 if ( isset( $matches[4] ) ) {
 896                                                         $query .= $matches[4];
 897                                                 }
 898                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 899                                                 if ( $query != '' ) {
 900                                                         $url = wfAppendQuery( $url, $query );
 901                                                 }
 902                                         }
 903                                 }
 904                                 if ( $url === false ) {
 905                                         if ( $query == '-' ) {
 906                                                 $query = '';
 907                                         }
 908                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 909                                 }
 910                         }
 911
 912                         // FIXME: this causes breakage in various places when we
 913                         // actually expected a local URL and end up with dupe prefixes.
 914                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 915                                 $url = $wgServer . $url;
 916                         }
 917                 }
 918                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 919                 return $url;
 920         }
 921
 922         /**
 923          * Get a URL that's the simplest URL that will be valid to link, locally,
 924          * to the current Title.  It includes the fragment, but does not include
 925          * the server unless action=render is used (or the link is external).  If
 926          * there's a fragment but the prefixed text is empty, we just return a link
 927          * to the fragment.
 928          *
 929          * The result obviously should not be URL-escaped, but does need to be
 930          * HTML-escaped if it's being output in HTML.
 931          *
 932          * @param $query Array of Strings An associative array of key => value pairs for the
 933          *   query string.  Keys and values will be escaped.
 934          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 935          *   for external links.  Default is "false" (same variant as current page,
 936          *   for anonymous users).
 937          * @return String the URL
 938          */
 939         public function getLinkUrl( $query = array(), $variant = false ) {
 940                 wfProfileIn( __METHOD__ );
 941                 if ( $this->isExternal() ) {
 942                         $ret = $this->getFullURL( $query );
 943                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 944                         $ret = $this->getFragmentForURL();
 945                 } else {
 946                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 947                 }
 948                 wfProfileOut( __METHOD__ );
 949                 return $ret;
 950         }
 951
 952         /**
 953          * Get an HTML-escaped version of the URL form, suitable for
 954          * using in a link, without a server name or fragment
 955          *
 956          * @param $query String an optional query string
 957          * @return String the URL
 958          */
 959         public function escapeLocalURL( $query = '' ) {
 960                 return htmlspecialchars( $this->getLocalURL( $query ) );
 961         }
 962
 963         /**
 964          * Get an HTML-escaped version of the URL form, suitable for
 965          * using in a link, including the server name and fragment
 966          *
 967          * @param $query String an optional query string
 968          * @return String the URL
 969          */
 970         public function escapeFullURL( $query = '' ) {
 971                 return htmlspecialchars( $this->getFullURL( $query ) );
 972         }
 973
 974         /**
 975          * Get the URL form for an internal link.
 976          * - Used in various Squid-related code, in case we have a different
 977          * internal hostname for the server from the exposed one.
 978          *
 979          * @param $query String an optional query string
 980          * @param $variant String language variant of url (for sr, zh..)
 981          * @return String the URL
 982          */
 983         public function getInternalURL( $query = '', $variant = false ) {
 984                 global $wgInternalServer, $wgServer;
 985                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
 986                 $url = $server . $this->getLocalURL( $query, $variant );
 987                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
 988                 return $url;
 989         }
 990
 991         /**
 992          * Get the edit URL for this Title
 993          *
 994          * @return String the URL, or a null string if this is an
 995          *  interwiki link
 996          */
 997         public function getEditURL() {
 998                 if ( $this->mInterwiki != '' ) {
 999                         return '';
1000                 }
1001                 $s = $this->getLocalURL( 'action=edit' );
1002
1003                 return $s;
1004         }
1005
1006         /**
1007          * Get the HTML-escaped displayable text form.
1008          * Used for the title field in <a> tags.
1009          *
1010          * @return String the text, including any prefixes
1011          */
1012         public function getEscapedText() {
1013                 return htmlspecialchars( $this->getPrefixedText() );
1014         }
1015
1016         /**
1017          * Is this Title interwiki?
1018          *
1019          * @return Bool
1020          */
1021         public function isExternal() {
1022                 return ( $this->mInterwiki != '' );
1023         }
1024
1025         /**
1026          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1027          *
1028          * @param $action String Action to check (default: edit)
1029          * @return Bool
1030          */
1031         public function isSemiProtected( $action = 'edit' ) {
1032                 if ( $this->exists() ) {
1033                         $restrictions = $this->getRestrictions( $action );
1034                         if ( count( $restrictions ) > 0 ) {
1035                                 foreach ( $restrictions as $restriction ) {
1036                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1037                                                 return false;
1038                                         }
1039                                 }
1040                         } else {
1041                                 # Not protected
1042                                 return false;
1043                         }
1044                         return true;
1045                 } else {
1046                         # If it doesn't exist, it can't be protected
1047                         return false;
1048                 }
1049         }
1050
1051         /**
1052          * Does the title correspond to a protected article?
1053          *
1054          * @param $action String the action the page is protected from,
1055          * by default checks all actions.
1056          * @return Bool
1057          */
1058         public function isProtected( $action = '' ) {
1059                 global $wgRestrictionLevels;
1060
1061                 $restrictionTypes = $this->getRestrictionTypes();
1062
1063                 # Special pages have inherent protection
1064                 if( $this->getNamespace() == NS_SPECIAL ) {
1065                         return true;
1066                 }
1067
1068                 # Check regular protection levels
1069                 foreach ( $restrictionTypes as $type ) {
1070                         if ( $action == $type || $action == '' ) {
1071                                 $r = $this->getRestrictions( $type );
1072                                 foreach ( $wgRestrictionLevels as $level ) {
1073                                         if ( in_array( $level, $r ) && $level != '' ) {
1074                                                 return true;
1075                                         }
1076                                 }
1077                         }
1078                 }
1079
1080                 return false;
1081         }
1082
1083         /**
1084          * Is this a conversion table for the LanguageConverter?
1085          *
1086          * @return Bool
1087          */
1088         public function isConversionTable() {
1089                 if(
1090                         $this->getNamespace() == NS_MEDIAWIKI &&
1091                         strpos( $this->getText(), 'Conversiontable' ) !== false
1092                 )
1093                 {
1094                         return true;
1095                 }
1096
1097                 return false;
1098         }
1099
1100         /**
1101          * Is $wgUser watching this page?
1102          *
1103          * @return Bool
1104          */
1105         public function userIsWatching() {
1106                 global $wgUser;
1107
1108                 if ( is_null( $this->mWatched ) ) {
1109                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1110                                 $this->mWatched = false;
1111                         } else {
1112                                 $this->mWatched = $wgUser->isWatched( $this );
1113                         }
1114                 }
1115                 return $this->mWatched;
1116         }
1117
1118         /**
1119          * Can $wgUser perform $action on this page?
1120          * This skips potentially expensive cascading permission checks
1121          * as well as avoids expensive error formatting
1122          *
1123          * Suitable for use for nonessential UI controls in common cases, but
1124          * _not_ for functional access control.
1125          *
1126          * May provide false positives, but should never provide a false negative.
1127          *
1128          * @param $action String action that permission needs to be checked for
1129          * @return Bool
1130          */
1131         public function quickUserCan( $action ) {
1132                 return $this->userCan( $action, false );
1133         }
1134
1135         /**
1136          * Determines if $user is unable to edit this page because it has been protected
1137          * by $wgNamespaceProtection.
1138          *
1139          * @param $user User object, $wgUser will be used if not passed
1140          * @return Bool
1141          */
1142         public function isNamespaceProtected( User $user = null ) {
1143                 global $wgNamespaceProtection;
1144
1145                 if ( $user === null ) {
1146                         global $wgUser;
1147                         $user = $wgUser;
1148                 }
1149
1150                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1151                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1152                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1153                                         return true;
1154                                 }
1155                         }
1156                 }
1157                 return false;
1158         }
1159
1160         /**
1161          * Can $wgUser perform $action on this page?
1162          *
1163          * @param $action String action that permission needs to be checked for
1164          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1165          * @return Bool
1166          */
1167         public function userCan( $action, $doExpensiveQueries = true ) {
1168                 global $wgUser;
1169                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1170         }
1171
1172         /**
1173          * Can $user perform $action on this page?
1174          *
1175          * FIXME: This *does not* check throttles (User::pingLimiter()).
1176          *
1177          * @param $action String action that permission needs to be checked for
1178          * @param $user User to check
1179          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1180          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1181          * @return Array of arguments to wfMsg to explain permissions problems.
1182          */
1183         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1184                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1185
1186                 // Remove the errors being ignored.
1187                 foreach ( $errors as $index => $error ) {
1188                         $error_key = is_array( $error ) ? $error[0] : $error;
1189
1190                         if ( in_array( $error_key, $ignoreErrors ) ) {
1191                                 unset( $errors[$index] );
1192                         }
1193                 }
1194
1195                 return $errors;
1196         }
1197
1198         /**
1199          * Permissions checks that fail most often, and which are easiest to test.
1200          *
1201          * @param $action String the action to check
1202          * @param $user User user to check
1203          * @param $errors Array list of current errors
1204          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1205          * @param $short Boolean short circuit on first error
1206          *
1207          * @return Array list of errors
1208          */
1209         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1210                 if ( $action == 'create' ) {
1211                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1212                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1213                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1214                         }
1215                 } elseif ( $action == 'move' ) {
1216                         if ( !$user->isAllowed( 'move-rootuserpages' )
1217                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1218                                 // Show user page-specific message only if the user can move other pages
1219                                 $errors[] = array( 'cant-move-user-page' );
1220                         }
1221
1222                         // Check if user is allowed to move files if it's a file
1223                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1224                                 $errors[] = array( 'movenotallowedfile' );
1225                         }
1226
1227                         if ( !$user->isAllowed( 'move' ) ) {
1228                                 // User can't move anything
1229                                 global $wgGroupPermissions;
1230                                 $userCanMove = false;
1231                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1232                                         $userCanMove = $wgGroupPermissions['user']['move'];
1233                                 }
1234                                 $autoconfirmedCanMove = false;
1235                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1236                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1237                                 }
1238                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1239                                         // custom message if logged-in users without any special rights can move
1240                                         $errors[] = array( 'movenologintext' );
1241                                 } else {
1242                                         $errors[] = array( 'movenotallowed' );
1243                                 }
1244                         }
1245                 } elseif ( $action == 'move-target' ) {
1246                         if ( !$user->isAllowed( 'move' ) ) {
1247                                 // User can't move anything
1248                                 $errors[] = array( 'movenotallowed' );
1249                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1250                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1251                                 // Show user page-specific message only if the user can move other pages
1252                                 $errors[] = array( 'cant-move-to-user-page' );
1253                         }
1254                 } elseif ( !$user->isAllowed( $action ) ) {
1255                         // We avoid expensive display logic for quickUserCan's and such
1256                         $groups = false;
1257                         if ( !$short ) {
1258                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1259                                         User::getGroupsWithPermission( $action ) );
1260                         }
1261
1262                         if ( $groups ) {
1263                                 global $wgLang;
1264                                 $return = array(
1265                                         'badaccess-groups',
1266                                         $wgLang->commaList( $groups ),
1267                                         count( $groups )
1268                                 );
1269                         } else {
1270                                 $return = array( 'badaccess-group0' );
1271                         }
1272                         $errors[] = $return;
1273                 }
1274
1275                 return $errors;
1276         }
1277
1278         /**
1279          * Add the resulting error code to the errors array
1280          *
1281          * @param $errors Array list of current errors
1282          * @param $result Mixed result of errors
1283          *
1284          * @return Array list of errors
1285          */
1286         private function resultToError( $errors, $result ) {
1287                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1288                         // A single array representing an error
1289                         $errors[] = $result;
1290                 } else if ( is_array( $result ) && is_array( $result[0] ) ) {
1291                         // A nested array representing multiple errors
1292                         $errors = array_merge( $errors, $result );
1293                 } else if ( $result !== '' && is_string( $result ) ) {
1294                         // A string representing a message-id
1295                         $errors[] = array( $result );
1296                 } else if ( $result === false ) {
1297                         // a generic "We don't want them to do that"
1298                         $errors[] = array( 'badaccess-group0' );
1299                 }
1300                 return $errors;
1301         }
1302
1303         /**
1304          * Check various permission hooks
1305          *
1306          * @param $action String the action to check
1307          * @param $user User user to check
1308          * @param $errors Array list of current errors
1309          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1310          * @param $short Boolean short circuit on first error
1311          *
1312          * @return Array list of errors
1313          */
1314         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1315                 // Use getUserPermissionsErrors instead
1316                 $result = '';
1317                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1318                         return $result ? array() : array( array( 'badaccess-group0' ) );
1319                 }
1320                 // Check getUserPermissionsErrors hook
1321                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1322                         $errors = $this->resultToError( $errors, $result );
1323                 }
1324                 // Check getUserPermissionsErrorsExpensive hook
1325                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1326                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1327                         $errors = $this->resultToError( $errors, $result );
1328                 }
1329
1330                 return $errors;
1331         }
1332
1333         /**
1334          * Check permissions on special pages & namespaces
1335          *
1336          * @param $action String the action to check
1337          * @param $user User user to check
1338          * @param $errors Array list of current errors
1339          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1340          * @param $short Boolean short circuit on first error
1341          *
1342          * @return Array list of errors
1343          */
1344         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1345                 # Only 'createaccount' and 'execute' can be performed on
1346                 # special pages, which don't actually exist in the DB.
1347                 $specialOKActions = array( 'createaccount', 'execute' );
1348                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1349                         $errors[] = array( 'ns-specialprotected' );
1350                 }
1351
1352                 # Check $wgNamespaceProtection for restricted namespaces
1353                 if ( $this->isNamespaceProtected( $user ) ) {
1354                         $ns = $this->mNamespace == NS_MAIN ?
1355                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1356                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1357                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1358                 }
1359
1360                 return $errors;
1361         }
1362
1363         /**
1364          * Check CSS/JS sub-page permissions
1365          *
1366          * @param $action String the action to check
1367          * @param $user User user to check
1368          * @param $errors Array list of current errors
1369          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1370          * @param $short Boolean short circuit on first error
1371          *
1372          * @return Array list of errors
1373          */
1374         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1375                 # Protect css/js subpages of user pages
1376                 # XXX: this might be better using restrictions
1377                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssSubpage()
1378                 #      and $this->userCanEditJsSubpage() from working
1379                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1380                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1381                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1382                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1383                                 $errors[] = array( 'customcssjsprotected' );
1384                         } else if ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1385                                 $errors[] = array( 'customcssjsprotected' );
1386                         }
1387                 }
1388
1389                 return $errors;
1390         }
1391
1392         /**
1393          * Check against page_restrictions table requirements on this
1394          * page. The user must possess all required rights for this
1395          * action.
1396          *
1397          * @param $action String the action to check
1398          * @param $user User user to check
1399          * @param $errors Array list of current errors
1400          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1401          * @param $short Boolean short circuit on first error
1402          *
1403          * @return Array list of errors
1404          */
1405         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1406                 foreach ( $this->getRestrictions( $action ) as $right ) {
1407                         // Backwards compatibility, rewrite sysop -> protect
1408                         if ( $right == 'sysop' ) {
1409                                 $right = 'protect';
1410                         }
1411                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1412                                 // Users with 'editprotected' permission can edit protected pages
1413                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected' ) ) {
1414                                         // Users with 'editprotected' permission cannot edit protected pages
1415                                         // with cascading option turned on.
1416                                         if ( $this->mCascadeRestriction ) {
1417                                                 $errors[] = array( 'protectedpagetext', $right );
1418                                         }
1419                                 } else {
1420                                         $errors[] = array( 'protectedpagetext', $right );
1421                                 }
1422                         }
1423                 }
1424
1425                 return $errors;
1426         }
1427
1428         /**
1429          * Check restrictions on cascading pages.
1430          *
1431          * @param $action String the action to check
1432          * @param $user User to check
1433          * @param $errors Array list of current errors
1434          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1435          * @param $short Boolean short circuit on first error
1436          *
1437          * @return Array list of errors
1438          */
1439         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1440                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1441                         # We /could/ use the protection level on the source page, but it's
1442                         # fairly ugly as we have to establish a precedence hierarchy for pages
1443                         # included by multiple cascade-protected pages. So just restrict
1444                         # it to people with 'protect' permission, as they could remove the
1445                         # protection anyway.
1446                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1447                         # Cascading protection depends on more than this page...
1448                         # Several cascading protected pages may include this page...
1449                         # Check each cascading level
1450                         # This is only for protection restrictions, not for all actions
1451                         if ( isset( $restrictions[$action] ) ) {
1452                                 foreach ( $restrictions[$action] as $right ) {
1453                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1454                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1455                                                 $pages = '';
1456                                                 foreach ( $cascadingSources as $page )
1457                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1458                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1459                                         }
1460                                 }
1461                         }
1462                 }
1463
1464                 return $errors;
1465         }
1466
1467         /**
1468          * Check action permissions not already checked in checkQuickPermissions
1469          *
1470          * @param $action String the action to check
1471          * @param $user User to check
1472          * @param $errors Array list of current errors
1473          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1474          * @param $short Boolean short circuit on first error
1475          *
1476          * @return Array list of errors
1477          */
1478         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1479                 if ( $action == 'protect' ) {
1480                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1481                                 // If they can't edit, they shouldn't protect.
1482                                 $errors[] = array( 'protect-cantedit' );
1483                         }
1484                 } elseif ( $action == 'create' ) {
1485                         $title_protection = $this->getTitleProtection();
1486                         if( $title_protection ) {
1487                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1488                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1489                                 }
1490                                 if( $title_protection['pt_create_perm'] == '' || !$user->isAllowed( $title_protection['pt_create_perm'] ) ) {
1491                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1492                                 }
1493                         }
1494                 } elseif ( $action == 'move' ) {
1495                         // Check for immobile pages
1496                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1497                                 // Specific message for this case
1498                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1499                         } elseif ( !$this->isMovable() ) {
1500                                 // Less specific message for rarer cases
1501                                 $errors[] = array( 'immobile-page' );
1502                         }
1503                 } elseif ( $action == 'move-target' ) {
1504                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1505                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1506                         } elseif ( !$this->isMovable() ) {
1507                                 $errors[] = array( 'immobile-target-page' );
1508                         }
1509                 }
1510                 return $errors;
1511         }
1512
1513         /**
1514          * Check that the user isn't blocked from editting.
1515          *
1516          * @param $action String the action to check
1517          * @param $user User to check
1518          * @param $errors Array list of current errors
1519          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1520          * @param $short Boolean short circuit on first error
1521          *
1522          * @return Array list of errors
1523          */
1524         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1525                 if( $short && count( $errors ) > 0 ) {
1526                         return $errors;
1527                 }
1528
1529                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1530
1531                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1532                         $errors[] = array( 'confirmedittext' );
1533                 }
1534
1535                 if ( in_array( $action, array( 'read', 'createaccount', 'unblock' ) ) ){
1536                         // Edit blocks should not affect reading.
1537                         // Account creation blocks handled at userlogin.
1538                         // Unblocking handled in SpecialUnblock
1539                 } elseif( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ){
1540                         // Don't block the user from editing their own talk page unless they've been
1541                         // explicitly blocked from that too.
1542                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1543                         $block = $user->mBlock;
1544
1545                         // This is from OutputPage::blockedPage
1546                         // Copied at r23888 by werdna
1547
1548                         $id = $user->blockedBy();
1549                         $reason = $user->blockedFor();
1550                         if ( $reason == '' ) {
1551                                 $reason = wfMsg( 'blockednoreason' );
1552                         }
1553                         $ip = wfGetIP();
1554
1555                         if ( is_numeric( $id ) ) {
1556                                 $name = User::whoIs( $id );
1557                         } else {
1558                                 $name = $id;
1559                         }
1560
1561                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1562                         $blockid = $block->getId();
1563                         $blockExpiry = $user->mBlock->mExpiry;
1564                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1565                         if ( $blockExpiry == 'infinity' ) {
1566                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1567                         } else {
1568                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1569                         }
1570
1571                         $intended = strval( $user->mBlock->getTarget() );
1572
1573                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1574                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1575                 }
1576
1577                 return $errors;
1578         }
1579
1580         /**
1581          * Can $user perform $action on this page? This is an internal function,
1582          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1583          * checks on wfReadOnly() and blocks)
1584          *
1585          * @param $action String action that permission needs to be checked for
1586          * @param $user User to check
1587          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1588          * @param $short Bool Set this to true to stop after the first permission error.
1589          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1590          */
1591         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1592                 wfProfileIn( __METHOD__ );
1593
1594                 $errors = array();
1595                 $checks = array(
1596                         'checkQuickPermissions',
1597                         'checkPermissionHooks',
1598                         'checkSpecialsAndNSPermissions',
1599                         'checkCSSandJSPermissions',
1600                         'checkPageRestrictions',
1601                         'checkCascadingSourcesRestrictions',
1602                         'checkActionPermissions',
1603                         'checkUserBlock'
1604                 );
1605
1606                 while( count( $checks ) > 0 &&
1607                            !( $short && count( $errors ) > 0 ) ) {
1608                         $method = array_shift( $checks );
1609                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1610                 }
1611
1612                 wfProfileOut( __METHOD__ );
1613                 return $errors;
1614         }
1615
1616         /**
1617          * Is this title subject to title protection?
1618          * Title protection is the one applied against creation of such title.
1619          *
1620          * @return Mixed An associative array representing any existent title
1621          *   protection, or false if there's none.
1622          */
1623         private function getTitleProtection() {
1624                 // Can't protect pages in special namespaces
1625                 if ( $this->getNamespace() < 0 ) {
1626                         return false;
1627                 }
1628
1629                 // Can't protect pages that exist.
1630                 if ( $this->exists() ) {
1631                         return false;
1632                 }
1633
1634                 if ( !isset( $this->mTitleProtection ) ) {
1635                         $dbr = wfGetDB( DB_SLAVE );
1636                         $res = $dbr->select( 'protected_titles', '*',
1637                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1638                                 __METHOD__ );
1639
1640                         // fetchRow returns false if there are no rows.
1641                         $this->mTitleProtection = $dbr->fetchRow( $res );
1642                 }
1643                 return $this->mTitleProtection;
1644         }
1645
1646         /**
1647          * Update the title protection status
1648          *
1649          * @param $create_perm String Permission required for creation
1650          * @param $reason String Reason for protection
1651          * @param $expiry String Expiry timestamp
1652          * @return boolean true
1653          */
1654         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1655                 global $wgUser, $wgContLang;
1656
1657                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1658                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1659                         // No change
1660                         return true;
1661                 }
1662
1663                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1664
1665                 $dbw = wfGetDB( DB_MASTER );
1666
1667                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
1668
1669                 $expiry_description = '';
1670                 if ( $encodedExpiry != $dbw->getInfinity() ) {
1671                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1672                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1673                 } else {
1674                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1675                 }
1676
1677                 # Update protection table
1678                 if ( $create_perm != '' ) {
1679                         $this->mTitleProtection = array(
1680                                         'pt_namespace' => $namespace,
1681                                         'pt_title' => $title,
1682                                         'pt_create_perm' => $create_perm,
1683                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
1684                                         'pt_expiry' => $encodedExpiry,
1685                                         'pt_user' => $wgUser->getId(),
1686                                         'pt_reason' => $reason,
1687                                 );
1688                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1689                                 $this->mTitleProtection, __METHOD__     );
1690                 } else {
1691                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1692                                 'pt_title' => $title ), __METHOD__ );
1693                         $this->mTitleProtection = false;
1694                 }
1695
1696                 # Update the protection log
1697                 if ( $dbw->affectedRows() ) {
1698                         $log = new LogPage( 'protect' );
1699
1700                         if ( $create_perm ) {
1701                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1702                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1703                         } else {
1704                                 $log->addEntry( 'unprotect', $this, $reason );
1705                         }
1706                 }
1707
1708                 return true;
1709         }
1710
1711         /**
1712          * Remove any title protection due to page existing
1713          */
1714         public function deleteTitleProtection() {
1715                 $dbw = wfGetDB( DB_MASTER );
1716
1717                 $dbw->delete(
1718                         'protected_titles',
1719                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1720                         __METHOD__
1721                 );
1722                 $this->mTitleProtection = false;
1723         }
1724
1725         /**
1726          * Would anybody with sufficient privileges be able to move this page?
1727          * Some pages just aren't movable.
1728          *
1729          * @return Bool TRUE or FALSE
1730          */
1731         public function isMovable() {
1732                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1733         }
1734
1735         /**
1736          * Can $wgUser read this page?
1737          *
1738          * @return Bool
1739          * @todo fold these checks into userCan()
1740          */
1741         public function userCanRead() {
1742                 global $wgUser, $wgGroupPermissions;
1743
1744                 static $useShortcut = null;
1745
1746                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1747                 if ( is_null( $useShortcut ) ) {
1748                         global $wgRevokePermissions;
1749                         $useShortcut = true;
1750                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1751                                 # Not a public wiki, so no shortcut
1752                                 $useShortcut = false;
1753                         } elseif ( !empty( $wgRevokePermissions ) ) {
1754                                 /*
1755                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1756                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1757                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1758                                  * reading is allowed.
1759                                  */
1760                                 foreach ( $wgRevokePermissions as $perms ) {
1761                                         if ( !empty( $perms['read'] ) ) {
1762                                                 # We might be removing the read right from the user, so no shortcut
1763                                                 $useShortcut = false;
1764                                                 break;
1765                                         }
1766                                 }
1767                         }
1768                 }
1769
1770                 $result = null;
1771                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1772                 if ( $result !== null ) {
1773                         return $result;
1774                 }
1775
1776                 # Shortcut for public wikis, allows skipping quite a bit of code
1777                 if ( $useShortcut ) {
1778                         return true;
1779                 }
1780
1781                 if ( $wgUser->isAllowed( 'read' ) ) {
1782                         return true;
1783                 } else {
1784                         global $wgWhitelistRead;
1785
1786                         # Always grant access to the login page.
1787                         # Even anons need to be able to log in.
1788                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1789                                 return true;
1790                         }
1791
1792                         # Bail out if there isn't whitelist
1793                         if ( !is_array( $wgWhitelistRead ) ) {
1794                                 return false;
1795                         }
1796
1797                         # Check for explicit whitelisting
1798                         $name = $this->getPrefixedText();
1799                         $dbName = $this->getPrefixedDBKey();
1800                         // Check with and without underscores
1801                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1802                                 return true;
1803
1804                         # Old settings might have the title prefixed with
1805                         # a colon for main-namespace pages
1806                         if ( $this->getNamespace() == NS_MAIN ) {
1807                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1808                                         return true;
1809                                 }
1810                         }
1811
1812                         # If it's a special page, ditch the subpage bit and check again
1813                         if ( $this->getNamespace() == NS_SPECIAL ) {
1814                                 $name = $this->getDBkey();
1815                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
1816                                 if ( $name === false ) {
1817                                         # Invalid special page, but we show standard login required message
1818                                         return false;
1819                                 }
1820
1821                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1822                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1823                                         return true;
1824                                 }
1825                         }
1826
1827                 }
1828                 return false;
1829         }
1830
1831         /**
1832          * Is this the mainpage?
1833          * @note Title::newFromText seams to be sufficiently optimized by the title
1834          * cache that we don't need to over-optimize by doing direct comparisons and
1835          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1836          * ends up reporting something differently than $title->isMainPage();
1837          *
1838          * @return Bool
1839          */
1840         public function isMainPage() {
1841                 return $this->equals( Title::newMainPage() );
1842         }
1843
1844         /**
1845          * Is this a talk page of some sort?
1846          *
1847          * @return Bool
1848          */
1849         public function isTalkPage() {
1850                 return MWNamespace::isTalk( $this->getNamespace() );
1851         }
1852
1853         /**
1854          * Is this a subpage?
1855          *
1856          * @return Bool
1857          */
1858         public function isSubpage() {
1859                 return MWNamespace::hasSubpages( $this->mNamespace )
1860                         ? strpos( $this->getText(), '/' ) !== false
1861                         : false;
1862         }
1863
1864         /**
1865          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1866          *
1867          * @return Bool
1868          */
1869         public function hasSubpages() {
1870                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1871                         # Duh
1872                         return false;
1873                 }
1874
1875                 # We dynamically add a member variable for the purpose of this method
1876                 # alone to cache the result.  There's no point in having it hanging
1877                 # around uninitialized in every Title object; therefore we only add it
1878                 # if needed and don't declare it statically.
1879                 if ( isset( $this->mHasSubpages ) ) {
1880                         return $this->mHasSubpages;
1881                 }
1882
1883                 $subpages = $this->getSubpages( 1 );
1884                 if ( $subpages instanceof TitleArray ) {
1885                         return $this->mHasSubpages = (bool)$subpages->count();
1886                 }
1887                 return $this->mHasSubpages = false;
1888         }
1889
1890         /**
1891          * Get all subpages of this page.
1892          *
1893          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
1894          * @return mixed TitleArray, or empty array if this page's namespace
1895          *  doesn't allow subpages
1896          */
1897         public function getSubpages( $limit = -1 ) {
1898                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1899                         return array();
1900                 }
1901
1902                 $dbr = wfGetDB( DB_SLAVE );
1903                 $conds['page_namespace'] = $this->getNamespace();
1904                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1905                 $options = array();
1906                 if ( $limit > -1 ) {
1907                         $options['LIMIT'] = $limit;
1908                 }
1909                 return $this->mSubpages = TitleArray::newFromResult(
1910                         $dbr->select( 'page',
1911                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1912                                 $conds,
1913                                 __METHOD__,
1914                                 $options
1915                         )
1916                 );
1917         }
1918
1919         /**
1920          * Could this page contain custom CSS or JavaScript, based
1921          * on the title?
1922          *
1923          * @return Bool
1924          */
1925         public function isCssOrJsPage() {
1926                 return $this->mNamespace == NS_MEDIAWIKI
1927                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1928         }
1929
1930         /**
1931          * Is this a .css or .js subpage of a user page?
1932          * @return Bool
1933          */
1934         public function isCssJsSubpage() {
1935                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1936         }
1937
1938         /**
1939          * Is this a *valid* .css or .js subpage of a user page?
1940          *
1941          * @return Bool
1942          * @deprecated since 1.17
1943          */
1944         public function isValidCssJsSubpage() {
1945                 return $this->isCssJsSubpage();
1946         }
1947
1948         /**
1949          * Trim down a .css or .js subpage title to get the corresponding skin name
1950          *
1951          * @return string containing skin name from .css or .js subpage title
1952          */
1953         public function getSkinFromCssJsSubpage() {
1954                 $subpage = explode( '/', $this->mTextform );
1955                 $subpage = $subpage[ count( $subpage ) - 1 ];
1956                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1957         }
1958
1959         /**
1960          * Is this a .css subpage of a user page?
1961          *
1962          * @return Bool
1963          */
1964         public function isCssSubpage() {
1965                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1966         }
1967
1968         /**
1969          * Is this a .js subpage of a user page?
1970          *
1971          * @return Bool
1972          */
1973         public function isJsSubpage() {
1974                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1975         }
1976
1977         /**
1978          * Protect css subpages of user pages: can $wgUser edit
1979          * this page?
1980          *
1981          * @return Bool
1982          * @todo XXX: this might be better using restrictions
1983          */
1984         public function userCanEditCssSubpage() {
1985                 global $wgUser;
1986                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
1987                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1988         }
1989
1990         /**
1991          * Protect js subpages of user pages: can $wgUser edit
1992          * this page?
1993          *
1994          * @return Bool
1995          * @todo XXX: this might be better using restrictions
1996          */
1997         public function userCanEditJsSubpage() {
1998                 global $wgUser;
1999                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2000                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2001         }
2002
2003         /**
2004          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2005          *
2006          * @return Bool If the page is subject to cascading restrictions.
2007          */
2008         public function isCascadeProtected() {
2009                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2010                 return ( $sources > 0 );
2011         }
2012
2013         /**
2014          * Cascading protection: Get the source of any cascading restrictions on this page.
2015          *
2016          * @param $getPages Bool Whether or not to retrieve the actual pages
2017          *        that the restrictions have come from.
2018          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2019          *     have come, false for none, or true if such restrictions exist, but $getPages
2020          *     was not set.  The restriction array is an array of each type, each of which
2021          *     contains a array of unique groups.
2022          */
2023         public function getCascadeProtectionSources( $getPages = true ) {
2024                 global $wgContLang;
2025                 $pagerestrictions = array();
2026
2027                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2028                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2029                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2030                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2031                 }
2032
2033                 wfProfileIn( __METHOD__ );
2034
2035                 $dbr = wfGetDB( DB_SLAVE );
2036
2037                 if ( $this->getNamespace() == NS_FILE ) {
2038                         $tables = array( 'imagelinks', 'page_restrictions' );
2039                         $where_clauses = array(
2040                                 'il_to' => $this->getDBkey(),
2041                                 'il_from=pr_page',
2042                                 'pr_cascade' => 1
2043                         );
2044                 } else {
2045                         $tables = array( 'templatelinks', 'page_restrictions' );
2046                         $where_clauses = array(
2047                                 'tl_namespace' => $this->getNamespace(),
2048                                 'tl_title' => $this->getDBkey(),
2049                                 'tl_from=pr_page',
2050                                 'pr_cascade' => 1
2051                         );
2052                 }
2053
2054                 if ( $getPages ) {
2055                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2056                                                    'pr_expiry', 'pr_type', 'pr_level' );
2057                         $where_clauses[] = 'page_id=pr_page';
2058                         $tables[] = 'page';
2059                 } else {
2060                         $cols = array( 'pr_expiry' );
2061                 }
2062
2063                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2064
2065                 $sources = $getPages ? array() : false;
2066                 $now = wfTimestampNow();
2067                 $purgeExpired = false;
2068
2069                 foreach ( $res as $row ) {
2070                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2071                         if ( $expiry > $now ) {
2072                                 if ( $getPages ) {
2073                                         $page_id = $row->pr_page;
2074                                         $page_ns = $row->page_namespace;
2075                                         $page_title = $row->page_title;
2076                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2077                                         # Add groups needed for each restriction type if its not already there
2078                                         # Make sure this restriction type still exists
2079
2080                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2081                                                 $pagerestrictions[$row->pr_type] = array();
2082                                         }
2083
2084                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2085                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2086                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2087                                         }
2088                                 } else {
2089                                         $sources = true;
2090                                 }
2091                         } else {
2092                                 // Trigger lazy purge of expired restrictions from the db
2093                                 $purgeExpired = true;
2094                         }
2095                 }
2096                 if ( $purgeExpired ) {
2097                         Title::purgeExpiredRestrictions();
2098                 }
2099
2100                 if ( $getPages ) {
2101                         $this->mCascadeSources = $sources;
2102                         $this->mCascadingRestrictions = $pagerestrictions;
2103                 } else {
2104                         $this->mHasCascadingRestrictions = $sources;
2105                 }
2106
2107                 wfProfileOut( __METHOD__ );
2108                 return array( $sources, $pagerestrictions );
2109         }
2110
2111         /**
2112          * Returns cascading restrictions for the current article
2113          *
2114          * @return Boolean
2115          */
2116         function areRestrictionsCascading() {
2117                 if ( !$this->mRestrictionsLoaded ) {
2118                         $this->loadRestrictions();
2119                 }
2120
2121                 return $this->mCascadeRestriction;
2122         }
2123
2124         /**
2125          * Loads a string into mRestrictions array
2126          *
2127          * @param $res Resource restrictions as an SQL result.
2128          * @param $oldFashionedRestrictions String comma-separated list of page
2129          *        restrictions from page table (pre 1.10)
2130          */
2131         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2132                 $rows = array();
2133
2134                 foreach ( $res as $row ) {
2135                         $rows[] = $row;
2136                 }
2137
2138                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2139         }
2140
2141         /**
2142          * Compiles list of active page restrictions from both page table (pre 1.10)
2143          * and page_restrictions table for this existing page.
2144          * Public for usage by LiquidThreads.
2145          *
2146          * @param $rows array of db result objects
2147          * @param $oldFashionedRestrictions string comma-separated list of page
2148          *        restrictions from page table (pre 1.10)
2149          */
2150         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2151                 global $wgContLang;
2152                 $dbr = wfGetDB( DB_SLAVE );
2153
2154                 $restrictionTypes = $this->getRestrictionTypes();
2155
2156                 foreach ( $restrictionTypes as $type ) {
2157                         $this->mRestrictions[$type] = array();
2158                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2159                 }
2160
2161                 $this->mCascadeRestriction = false;
2162
2163                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2164
2165                 if ( $oldFashionedRestrictions === null ) {
2166                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2167                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2168                 }
2169
2170                 if ( $oldFashionedRestrictions != '' ) {
2171
2172                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2173                                 $temp = explode( '=', trim( $restrict ) );
2174                                 if ( count( $temp ) == 1 ) {
2175                                         // old old format should be treated as edit/move restriction
2176                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2177                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2178                                 } else {
2179                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2180                                 }
2181                         }
2182
2183                         $this->mOldRestrictions = true;
2184
2185                 }
2186
2187                 if ( count( $rows ) ) {
2188                         # Current system - load second to make them override.
2189                         $now = wfTimestampNow();
2190                         $purgeExpired = false;
2191
2192                         # Cycle through all the restrictions.
2193                         foreach ( $rows as $row ) {
2194
2195                                 // Don't take care of restrictions types that aren't allowed
2196                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2197                                         continue;
2198
2199                                 // This code should be refactored, now that it's being used more generally,
2200                                 // But I don't really see any harm in leaving it in Block for now -werdna
2201                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2202
2203                                 // Only apply the restrictions if they haven't expired!
2204                                 if ( !$expiry || $expiry > $now ) {
2205                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2206                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2207
2208                                         $this->mCascadeRestriction |= $row->pr_cascade;
2209                                 } else {
2210                                         // Trigger a lazy purge of expired restrictions
2211                                         $purgeExpired = true;
2212                                 }
2213                         }
2214
2215                         if ( $purgeExpired ) {
2216                                 Title::purgeExpiredRestrictions();
2217                         }
2218                 }
2219
2220                 $this->mRestrictionsLoaded = true;
2221         }
2222
2223         /**
2224          * Load restrictions from the page_restrictions table
2225          *
2226          * @param $oldFashionedRestrictions String comma-separated list of page
2227          *        restrictions from page table (pre 1.10)
2228          */
2229         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2230                 global $wgContLang;
2231                 if ( !$this->mRestrictionsLoaded ) {
2232                         if ( $this->exists() ) {
2233                                 $dbr = wfGetDB( DB_SLAVE );
2234
2235                                 $res = $dbr->select(
2236                                         'page_restrictions',
2237                                         '*',
2238                                         array( 'pr_page' => $this->getArticleId() ),
2239                                         __METHOD__
2240                                 );
2241
2242                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2243                         } else {
2244                                 $title_protection = $this->getTitleProtection();
2245
2246                                 if ( $title_protection ) {
2247                                         $now = wfTimestampNow();
2248                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2249
2250                                         if ( !$expiry || $expiry > $now ) {
2251                                                 // Apply the restrictions
2252                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2253                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2254                                         } else { // Get rid of the old restrictions
2255                                                 Title::purgeExpiredRestrictions();
2256                                                 $this->mTitleProtection = false;
2257                                         }
2258                                 } else {
2259                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2260                                 }
2261                                 $this->mRestrictionsLoaded = true;
2262                         }
2263                 }
2264         }
2265
2266         /**
2267          * Purge expired restrictions from the page_restrictions table
2268          */
2269         static function purgeExpiredRestrictions() {
2270                 $dbw = wfGetDB( DB_MASTER );
2271                 $dbw->delete(
2272                         'page_restrictions',
2273                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2274                         __METHOD__
2275                 );
2276
2277                 $dbw->delete(
2278                         'protected_titles',
2279                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2280                         __METHOD__
2281                 );
2282         }
2283
2284         /**
2285          * Accessor/initialisation for mRestrictions
2286          *
2287          * @param $action String action that permission needs to be checked for
2288          * @return Array of Strings the array of groups allowed to edit this article
2289          */
2290         public function getRestrictions( $action ) {
2291                 if ( !$this->mRestrictionsLoaded ) {
2292                         $this->loadRestrictions();
2293                 }
2294                 return isset( $this->mRestrictions[$action] )
2295                                 ? $this->mRestrictions[$action]
2296                                 : array();
2297         }
2298
2299         /**
2300          * Get the expiry time for the restriction against a given action
2301          *
2302          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2303          *      or not protected at all, or false if the action is not recognised.
2304          */
2305         public function getRestrictionExpiry( $action ) {
2306                 if ( !$this->mRestrictionsLoaded ) {
2307                         $this->loadRestrictions();
2308                 }
2309                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2310         }
2311
2312         /**
2313          * Is there a version of this page in the deletion archive?
2314          *
2315          * @return Int the number of archived revisions
2316          */
2317         public function isDeleted() {
2318                 if ( $this->getNamespace() < 0 ) {
2319                         $n = 0;
2320                 } else {
2321                         $dbr = wfGetDB( DB_SLAVE );
2322                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2323                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2324                                 __METHOD__
2325                         );
2326                         if ( $this->getNamespace() == NS_FILE ) {
2327                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2328                                         array( 'fa_name' => $this->getDBkey() ),
2329                                         __METHOD__
2330                                 );
2331                         }
2332                 }
2333                 return (int)$n;
2334         }
2335
2336         /**
2337          * Is there a version of this page in the deletion archive?
2338          *
2339          * @return Boolean
2340          */
2341         public function isDeletedQuick() {
2342                 if ( $this->getNamespace() < 0 ) {
2343                         return false;
2344                 }
2345                 $dbr = wfGetDB( DB_SLAVE );
2346                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2347                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2348                         __METHOD__
2349                 );
2350                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2351                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2352                                 array( 'fa_name' => $this->getDBkey() ),
2353                                 __METHOD__
2354                         );
2355                 }
2356                 return $deleted;
2357         }
2358
2359         /**
2360          * Get the article ID for this Title from the link cache,
2361          * adding it if necessary
2362          *
2363          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2364          *  for update
2365          * @return Int the ID
2366          */
2367         public function getArticleID( $flags = 0 ) {
2368                 if ( $this->getNamespace() < 0 ) {
2369                         return $this->mArticleID = 0;
2370                 }
2371                 $linkCache = LinkCache::singleton();
2372                 if ( $flags & self::GAID_FOR_UPDATE ) {
2373                         $oldUpdate = $linkCache->forUpdate( true );
2374                         $linkCache->clearLink( $this );
2375                         $this->mArticleID = $linkCache->addLinkObj( $this );
2376                         $linkCache->forUpdate( $oldUpdate );
2377                 } else {
2378                         if ( -1 == $this->mArticleID ) {
2379                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2380                         }
2381                 }
2382                 return $this->mArticleID;
2383         }
2384
2385         /**
2386          * Is this an article that is a redirect page?
2387          * Uses link cache, adding it if necessary
2388          *
2389          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2390          * @return Bool
2391          */
2392         public function isRedirect( $flags = 0 ) {
2393                 if ( !is_null( $this->mRedirect ) ) {
2394                         return $this->mRedirect;
2395                 }
2396                 # Calling getArticleID() loads the field from cache as needed
2397                 if ( !$this->getArticleID( $flags ) ) {
2398                         return $this->mRedirect = false;
2399                 }
2400                 $linkCache = LinkCache::singleton();
2401                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2402
2403                 return $this->mRedirect;
2404         }
2405
2406         /**
2407          * What is the length of this page?
2408          * Uses link cache, adding it if necessary
2409          *
2410          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2411          * @return Int
2412          */
2413         public function getLength( $flags = 0 ) {
2414                 if ( $this->mLength != -1 ) {
2415                         return $this->mLength;
2416                 }
2417                 # Calling getArticleID() loads the field from cache as needed
2418                 if ( !$this->getArticleID( $flags ) ) {
2419                         return $this->mLength = 0;
2420                 }
2421                 $linkCache = LinkCache::singleton();
2422                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2423
2424                 return $this->mLength;
2425         }
2426
2427         /**
2428          * What is the page_latest field for this page?
2429          *
2430          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2431          * @return Int or 0 if the page doesn't exist
2432          */
2433         public function getLatestRevID( $flags = 0 ) {
2434                 if ( $this->mLatestID !== false ) {
2435                         return intval( $this->mLatestID );
2436                 }
2437                 # Calling getArticleID() loads the field from cache as needed
2438                 if ( !$this->getArticleID( $flags ) ) {
2439                         return $this->mLatestID = 0;
2440                 }
2441                 $linkCache = LinkCache::singleton();
2442                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2443
2444                 return $this->mLatestID;
2445         }
2446
2447         /**
2448          * This clears some fields in this object, and clears any associated
2449          * keys in the "bad links" section of the link cache.
2450          *
2451          * - This is called from Article::doEdit() and Article::insertOn() to allow
2452          * loading of the new page_id. It's also called from
2453          * Article::doDeleteArticle()
2454          *
2455          * @param $newid Int the new Article ID
2456          */
2457         public function resetArticleID( $newid ) {
2458                 $linkCache = LinkCache::singleton();
2459                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2460
2461                 if ( $newid === false ) {
2462                         $this->mArticleID = -1;
2463                 } else {
2464                         $this->mArticleID = intval( $newid );
2465                 }
2466                 $this->mRestrictionsLoaded = false;
2467                 $this->mRestrictions = array();
2468                 $this->mRedirect = null;
2469                 $this->mLength = -1;
2470                 $this->mLatestID = false;
2471         }
2472
2473         /**
2474          * Updates page_touched for this page; called from LinksUpdate.php
2475          *
2476          * @return Bool true if the update succeded
2477          */
2478         public function invalidateCache() {
2479                 if ( wfReadOnly() ) {
2480                         return;
2481                 }
2482                 $dbw = wfGetDB( DB_MASTER );
2483                 $success = $dbw->update(
2484                         'page',
2485                         array( 'page_touched' => $dbw->timestamp() ),
2486                         $this->pageCond(),
2487                         __METHOD__
2488                 );
2489                 HTMLFileCache::clearFileCache( $this );
2490                 return $success;
2491         }
2492
2493         /**
2494          * Prefix some arbitrary text with the namespace or interwiki prefix
2495          * of this object
2496          *
2497          * @param $name String the text
2498          * @return String the prefixed text
2499          * @private
2500          */
2501         /* private */ function prefix( $name ) {
2502                 $p = '';
2503                 if ( $this->mInterwiki != '' ) {
2504                         $p = $this->mInterwiki . ':';
2505                 }
2506
2507                 if ( 0 != $this->mNamespace ) {
2508                         $p .= $this->getNsText() . ':';
2509                 }
2510                 return $p . $name;
2511         }
2512
2513         /**
2514          * Returns a simple regex that will match on characters and sequences invalid in titles.
2515          * Note that this doesn't pick up many things that could be wrong with titles, but that
2516          * replacing this regex with something valid will make many titles valid.
2517          *
2518          * @return String regex string
2519          */
2520         static function getTitleInvalidRegex() {
2521                 static $rxTc = false;
2522                 if ( !$rxTc ) {
2523                         # Matching titles will be held as illegal.
2524                         $rxTc = '/' .
2525                                 # Any character not allowed is forbidden...
2526                                 '[^' . Title::legalChars() . ']' .
2527                                 # URL percent encoding sequences interfere with the ability
2528                                 # to round-trip titles -- you can't link to them consistently.
2529                                 '|%[0-9A-Fa-f]{2}' .
2530                                 # XML/HTML character references produce similar issues.
2531                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2532                                 '|&#[0-9]+;' .
2533                                 '|&#x[0-9A-Fa-f]+;' .
2534                                 '/S';
2535                 }
2536
2537                 return $rxTc;
2538         }
2539
2540         /**
2541          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2542          *
2543          * @param $text String containing title to capitalize
2544          * @param $ns int namespace index, defaults to NS_MAIN
2545          * @return String containing capitalized title
2546          */
2547         public static function capitalize( $text, $ns = NS_MAIN ) {
2548                 global $wgContLang;
2549
2550                 if ( MWNamespace::isCapitalized( $ns ) ) {
2551                         return $wgContLang->ucfirst( $text );
2552                 } else {
2553                         return $text;
2554                 }
2555         }
2556
2557         /**
2558          * Secure and split - main initialisation function for this object
2559          *
2560          * Assumes that mDbkeyform has been set, and is urldecoded
2561          * and uses underscores, but not otherwise munged.  This function
2562          * removes illegal characters, splits off the interwiki and
2563          * namespace prefixes, sets the other forms, and canonicalizes
2564          * everything.
2565          *
2566          * @return Bool true on success
2567          */
2568         private function secureAndSplit() {
2569                 global $wgContLang, $wgLocalInterwiki;
2570
2571                 # Initialisation
2572                 $this->mInterwiki = $this->mFragment = '';
2573                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2574
2575                 $dbkey = $this->mDbkeyform;
2576
2577                 # Strip Unicode bidi override characters.
2578                 # Sometimes they slip into cut-n-pasted page titles, where the
2579                 # override chars get included in list displays.
2580                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2581
2582                 # Clean up whitespace
2583                 # Note: use of the /u option on preg_replace here will cause
2584                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2585                 # conveniently disabling them.
2586                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2587                 $dbkey = trim( $dbkey, '_' );
2588
2589                 if ( $dbkey == '' ) {
2590                         return false;
2591                 }
2592
2593                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2594                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2595                         return false;
2596                 }
2597
2598                 $this->mDbkeyform = $dbkey;
2599
2600                 # Initial colon indicates main namespace rather than specified default
2601                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2602                 if ( ':' == $dbkey { 0 } ) {
2603                         $this->mNamespace = NS_MAIN;
2604                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2605                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2606                 }
2607
2608                 # Namespace or interwiki prefix
2609                 $firstPass = true;
2610                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2611                 do {
2612                         $m = array();
2613                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2614                                 $p = $m[1];
2615                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2616                                         # Ordinary namespace
2617                                         $dbkey = $m[2];
2618                                         $this->mNamespace = $ns;
2619                                         # For Talk:X pages, check if X has a "namespace" prefix
2620                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2621                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2622                                                         # Disallow Talk:File:x type titles...
2623                                                         return false;
2624                                                 } else if ( Interwiki::isValidInterwiki( $x[1] ) ) {
2625                                                         # Disallow Talk:Interwiki:x type titles...
2626                                                         return false;
2627                                                 }
2628                                         }
2629                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2630                                         if ( !$firstPass ) {
2631                                                 # Can't make a local interwiki link to an interwiki link.
2632                                                 # That's just crazy!
2633                                                 return false;
2634                                         }
2635
2636                                         # Interwiki link
2637                                         $dbkey = $m[2];
2638                                         $this->mInterwiki = $wgContLang->lc( $p );
2639
2640                                         # Redundant interwiki prefix to the local wiki
2641                                         if ( $wgLocalInterwiki !== false
2642                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2643                                         {
2644                                                 if ( $dbkey == '' ) {
2645                                                         # Can't have an empty self-link
2646                                                         return false;
2647                                                 }
2648                                                 $this->mInterwiki = '';
2649                                                 $firstPass = false;
2650                                                 # Do another namespace split...
2651                                                 continue;
2652                                         }
2653
2654                                         # If there's an initial colon after the interwiki, that also
2655                                         # resets the default namespace
2656                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2657                                                 $this->mNamespace = NS_MAIN;
2658                                                 $dbkey = substr( $dbkey, 1 );
2659                                         }
2660                                 }
2661                                 # If there's no recognized interwiki or namespace,
2662                                 # then let the colon expression be part of the title.
2663                         }
2664                         break;
2665                 } while ( true );
2666
2667                 # We already know that some pages won't be in the database!
2668                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2669                         $this->mArticleID = 0;
2670                 }
2671                 $fragment = strstr( $dbkey, '#' );
2672                 if ( false !== $fragment ) {
2673                         $this->setFragment( $fragment );
2674                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2675                         # remove whitespace again: prevents "Foo_bar_#"
2676                         # becoming "Foo_bar_"
2677                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2678                 }
2679
2680                 # Reject illegal characters.
2681                 $rxTc = self::getTitleInvalidRegex();
2682                 if ( preg_match( $rxTc, $dbkey ) ) {
2683                         return false;
2684                 }
2685
2686                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2687                 # reachable due to the way web browsers deal with 'relative' URLs.
2688                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2689                 if ( strpos( $dbkey, '.' ) !== false &&
2690                          ( $dbkey === '.' || $dbkey === '..' ||
2691                            strpos( $dbkey, './' ) === 0  ||
2692                            strpos( $dbkey, '../' ) === 0 ||
2693                            strpos( $dbkey, '/./' ) !== false ||
2694                            strpos( $dbkey, '/../' ) !== false  ||
2695                            substr( $dbkey, -2 ) == '/.' ||
2696                            substr( $dbkey, -3 ) == '/..' ) )
2697                 {
2698                         return false;
2699                 }
2700
2701                 # Magic tilde sequences? Nu-uh!
2702                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2703                         return false;
2704                 }
2705
2706                 # Limit the size of titles to 255 bytes. This is typically the size of the
2707                 # underlying database field. We make an exception for special pages, which
2708                 # don't need to be stored in the database, and may edge over 255 bytes due
2709                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2710                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2711                   strlen( $dbkey ) > 512 )
2712                 {
2713                         return false;
2714                 }
2715
2716                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2717                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2718                 # other site might be case-sensitive.
2719                 $this->mUserCaseDBKey = $dbkey;
2720                 if ( $this->mInterwiki == '' ) {
2721                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2722                 }
2723
2724                 # Can't make a link to a namespace alone... "empty" local links can only be
2725                 # self-links with a fragment identifier.
2726                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2727                         return false;
2728                 }
2729
2730                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2731                 // IP names are not allowed for accounts, and can only be referring to
2732                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2733                 // there are numerous ways to present the same IP. Having sp:contribs scan
2734                 // them all is silly and having some show the edits and others not is
2735                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2736                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2737                         ? IP::sanitizeIP( $dbkey )
2738                         : $dbkey;
2739
2740                 // Any remaining initial :s are illegal.
2741                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2742                         return false;
2743                 }
2744
2745                 # Fill fields
2746                 $this->mDbkeyform = $dbkey;
2747                 $this->mUrlform = wfUrlencode( $dbkey );
2748
2749                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2750
2751                 return true;
2752         }
2753
2754         /**
2755          * Set the fragment for this title. Removes the first character from the
2756          * specified fragment before setting, so it assumes you're passing it with
2757          * an initial "#".
2758          *
2759          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2760          * Still in active use privately.
2761          *
2762          * @param $fragment String text
2763          */
2764         public function setFragment( $fragment ) {
2765                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2766         }
2767
2768         /**
2769          * Get a Title object associated with the talk page of this article
2770          *
2771          * @return Title the object for the talk page
2772          */
2773         public function getTalkPage() {
2774                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2775         }
2776
2777         /**
2778          * Get a title object associated with the subject page of this
2779          * talk page
2780          *
2781          * @return Title the object for the subject page
2782          */
2783         public function getSubjectPage() {
2784                 // Is this the same title?
2785                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2786                 if ( $this->getNamespace() == $subjectNS ) {
2787                         return $this;
2788                 }
2789                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2790         }
2791
2792         /**
2793          * Get an array of Title objects linking to this Title
2794          * Also stores the IDs in the link cache.
2795          *
2796          * WARNING: do not use this function on arbitrary user-supplied titles!
2797          * On heavily-used templates it will max out the memory.
2798          *
2799          * @param $options Array: may be FOR UPDATE
2800          * @param $table String: table name
2801          * @param $prefix String: fields prefix
2802          * @return Array of Title objects linking here
2803          */
2804         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2805                 $linkCache = LinkCache::singleton();
2806
2807                 if ( count( $options ) > 0 ) {
2808                         $db = wfGetDB( DB_MASTER );
2809                 } else {
2810                         $db = wfGetDB( DB_SLAVE );
2811                 }
2812
2813                 $res = $db->select(
2814                         array( 'page', $table ),
2815                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2816                         array(
2817                                 "{$prefix}_from=page_id",
2818                                 "{$prefix}_namespace" => $this->getNamespace(),
2819                                 "{$prefix}_title"     => $this->getDBkey() ),
2820                         __METHOD__,
2821                         $options
2822                 );
2823
2824                 $retVal = array();
2825                 if ( $db->numRows( $res ) ) {
2826                         foreach ( $res as $row ) {
2827                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2828                                 if ( $titleObj ) {
2829                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2830                                         $retVal[] = $titleObj;
2831                                 }
2832                         }
2833                 }
2834                 return $retVal;
2835         }
2836
2837         /**
2838          * Get an array of Title objects using this Title as a template
2839          * Also stores the IDs in the link cache.
2840          *
2841          * WARNING: do not use this function on arbitrary user-supplied titles!
2842          * On heavily-used templates it will max out the memory.
2843          *
2844          * @param $options Array: may be FOR UPDATE
2845          * @return Array of Title the Title objects linking here
2846          */
2847         public function getTemplateLinksTo( $options = array() ) {
2848                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2849         }
2850
2851         /**
2852          * Get an array of Title objects referring to non-existent articles linked from this page
2853          *
2854          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2855          * @return Array of Title the Title objects
2856          */
2857         public function getBrokenLinksFrom() {
2858                 if ( $this->getArticleId() == 0 ) {
2859                         # All links from article ID 0 are false positives
2860                         return array();
2861                 }
2862
2863                 $dbr = wfGetDB( DB_SLAVE );
2864                 $res = $dbr->select(
2865                         array( 'page', 'pagelinks' ),
2866                         array( 'pl_namespace', 'pl_title' ),
2867                         array(
2868                                 'pl_from' => $this->getArticleId(),
2869                                 'page_namespace IS NULL'
2870                         ),
2871                         __METHOD__, array(),
2872                         array(
2873                                 'page' => array(
2874                                         'LEFT JOIN',
2875                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2876                                 )
2877                         )
2878                 );
2879
2880                 $retVal = array();
2881                 foreach ( $res as $row ) {
2882                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2883                 }
2884                 return $retVal;
2885         }
2886
2887
2888         /**
2889          * Get a list of URLs to purge from the Squid cache when this
2890          * page changes
2891          *
2892          * @return Array of String the URLs
2893          */
2894         public function getSquidURLs() {
2895                 global $wgContLang;
2896
2897                 $urls = array(
2898                         $this->getInternalURL(),
2899                         $this->getInternalURL( 'action=history' )
2900                 );
2901
2902                 // purge variant urls as well
2903                 if ( $wgContLang->hasVariants() ) {
2904                         $variants = $wgContLang->getVariants();
2905                         foreach ( $variants as $vCode ) {
2906                                 $urls[] = $this->getInternalURL( '', $vCode );
2907                         }
2908                 }
2909
2910                 return $urls;
2911         }
2912
2913         /**
2914          * Purge all applicable Squid URLs
2915          */
2916         public function purgeSquid() {
2917                 global $wgUseSquid;
2918                 if ( $wgUseSquid ) {
2919                         $urls = $this->getSquidURLs();
2920                         $u = new SquidUpdate( $urls );
2921                         $u->doUpdate();
2922                 }
2923         }
2924
2925         /**
2926          * Move this page without authentication
2927          *
2928          * @param $nt Title the new page Title
2929          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
2930          */
2931         public function moveNoAuth( &$nt ) {
2932                 return $this->moveTo( $nt, false );
2933         }
2934
2935         /**
2936          * Check whether a given move operation would be valid.
2937          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2938          *
2939          * @param $nt Title the new title
2940          * @param $auth Bool indicates whether $wgUser's permissions
2941          *  should be checked
2942          * @param $reason String is the log summary of the move, used for spam checking
2943          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
2944          */
2945         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2946                 global $wgUser;
2947
2948                 $errors = array();
2949                 if ( !$nt ) {
2950                         // Normally we'd add this to $errors, but we'll get
2951                         // lots of syntax errors if $nt is not an object
2952                         return array( array( 'badtitletext' ) );
2953                 }
2954                 if ( $this->equals( $nt ) ) {
2955                         $errors[] = array( 'selfmove' );
2956                 }
2957                 if ( !$this->isMovable() ) {
2958                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2959                 }
2960                 if ( $nt->getInterwiki() != '' ) {
2961                         $errors[] = array( 'immobile-target-namespace-iw' );
2962                 }
2963                 if ( !$nt->isMovable() ) {
2964                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
2965                 }
2966
2967                 $oldid = $this->getArticleID();
2968                 $newid = $nt->getArticleID();
2969
2970                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2971                         $errors[] = array( 'articleexists' );
2972                 }
2973                 if ( ( $this->getDBkey() == '' ) ||
2974                          ( !$oldid ) ||
2975                          ( $nt->getDBkey() == '' ) ) {
2976                         $errors[] = array( 'badarticleerror' );
2977                 }
2978
2979                 // Image-specific checks
2980                 if ( $this->getNamespace() == NS_FILE ) {
2981                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
2982                 }
2983
2984                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
2985                         $errors[] = array( 'nonfile-cannot-move-to-file' );
2986                 }
2987
2988                 if ( $auth ) {
2989                         $errors = wfMergeErrorArrays( $errors,
2990                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
2991                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
2992                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
2993                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
2994                 }
2995
2996                 $match = EditPage::matchSummarySpamRegex( $reason );
2997                 if ( $match !== false ) {
2998                         // This is kind of lame, won't display nice
2999                         $errors[] = array( 'spamprotectiontext' );
3000                 }
3001
3002                 $err = null;
3003                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3004                         $errors[] = array( 'hookaborted', $err );
3005                 }
3006
3007                 # The move is allowed only if (1) the target doesn't exist, or
3008                 # (2) the target is a redirect to the source, and has no history
3009                 # (so we can undo bad moves right after they're done).
3010
3011                 if ( 0 != $newid ) { # Target exists; check for validity
3012                         if ( !$this->isValidMoveTarget( $nt ) ) {
3013                                 $errors[] = array( 'articleexists' );
3014                         }
3015                 } else {
3016                         $tp = $nt->getTitleProtection();
3017                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3018                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3019                                 $errors[] = array( 'cantmove-titleprotected' );
3020                         }
3021                 }
3022                 if ( empty( $errors ) ) {
3023                         return true;
3024                 }
3025                 return $errors;
3026         }
3027
3028         /**
3029          * Check if the requested move target is a valid file move target
3030          * @param Title $nt Target title
3031          * @return array List of errors
3032          */
3033         protected function validateFileMoveOperation( $nt ) {
3034                 global $wgUser;
3035
3036                 $errors = array();
3037
3038                 if ( $nt->getNamespace() != NS_FILE ) {
3039                         $errors[] = array( 'imagenocrossnamespace' );
3040                 }
3041
3042                 $file = wfLocalFile( $this );
3043                 if ( $file->exists() ) {
3044                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3045                                 $errors[] = array( 'imageinvalidfilename' );
3046                         }
3047                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3048                                 $errors[] = array( 'imagetypemismatch' );
3049                         }
3050                 }
3051
3052                 $destFile = wfLocalFile( $nt );
3053                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3054                         $errors[] = array( 'file-exists-sharedrepo' );
3055                 }
3056
3057                 return $errors;
3058         }
3059
3060         /**
3061          * Move a title to a new location
3062          *
3063          * @param $nt Title the new title
3064          * @param $auth Bool indicates whether $wgUser's permissions
3065          *  should be checked
3066          * @param $reason String the reason for the move
3067          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3068          *  Ignored if the user doesn't have the suppressredirect right.
3069          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3070          */
3071         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3072                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3073                 if ( is_array( $err ) ) {
3074                         return $err;
3075                 }
3076
3077                 // If it is a file, move it first. It is done before all other moving stuff is
3078                 // done because it's hard to revert
3079                 $dbw = wfGetDB( DB_MASTER );
3080                 if ( $this->getNamespace() == NS_FILE ) {
3081                         $file = wfLocalFile( $this );
3082                         if ( $file->exists() ) {
3083                                 $status = $file->move( $nt );
3084                                 if ( !$status->isOk() ) {
3085                                         return $status->getErrorsArray();
3086                                 }
3087                         }
3088                 }
3089
3090                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3091                 $pageid = $this->getArticleID( GAID_FOR_UPDATE );
3092                 $protected = $this->isProtected();
3093                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3094
3095                 // Do the actual move
3096                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3097                 if ( is_array( $err ) ) {
3098                         # FIXME: What about the File we have already moved?
3099                         $dbw->rollback();
3100                         return $err;
3101                 }
3102
3103                 $redirid = $this->getArticleID();
3104
3105                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3106                 // cl_timestamp, which may disturb time-based lists on some sites.
3107                 $prefixes = $dbw->select(
3108                         'categorylinks',
3109                         array( 'cl_sortkey_prefix', 'cl_to' ),
3110                         array( 'cl_from' => $pageid ),
3111                         __METHOD__
3112                 );
3113                 foreach ( $prefixes as $prefixRow ) {
3114                         $prefix = $prefixRow->cl_sortkey_prefix;
3115                         $catTo = $prefixRow->cl_to;
3116                         $dbw->update( 'categorylinks',
3117                                 array(
3118                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3119                                                 $nt->getCategorySortkey( $prefix ) ),
3120                                         'cl_timestamp=cl_timestamp' ),
3121                                 array(
3122                                         'cl_from' => $pageid,
3123                                         'cl_to' => $catTo ),
3124                                 __METHOD__
3125                         );
3126                 }
3127
3128                 if ( $protected ) {
3129                         # Protect the redirect title as the title used to be...
3130                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3131                                 array(
3132                                         'pr_page'    => $redirid,
3133                                         'pr_type'    => 'pr_type',
3134                                         'pr_level'   => 'pr_level',
3135                                         'pr_cascade' => 'pr_cascade',
3136                                         'pr_user'    => 'pr_user',
3137                                         'pr_expiry'  => 'pr_expiry'
3138                                 ),
3139                                 array( 'pr_page' => $pageid ),
3140                                 __METHOD__,
3141                                 array( 'IGNORE' )
3142                         );
3143                         # Update the protection log
3144                         $log = new LogPage( 'protect' );
3145                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3146                         if ( $reason ) {
3147                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3148                         }
3149                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) ); // FIXME: $params?
3150                 }
3151
3152                 # Update watchlists
3153                 $oldnamespace = $this->getNamespace() & ~1;
3154                 $newnamespace = $nt->getNamespace() & ~1;
3155                 $oldtitle = $this->getDBkey();
3156                 $newtitle = $nt->getDBkey();
3157
3158                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3159                         WatchedItem::duplicateEntries( $this, $nt );
3160                 }
3161
3162                 # Update search engine
3163                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3164                 $u->doUpdate();
3165                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3166                 $u->doUpdate();
3167
3168                 $dbw->commit();
3169
3170                 # Update site_stats
3171                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3172                         # No longer a content page
3173                         # Not viewed, edited, removing
3174                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3175                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3176                         # Now a content page
3177                         # Not viewed, edited, adding
3178                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3179                 } elseif ( $pageCountChange ) {
3180                         # Redirect added
3181                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3182                 } else {
3183                         # Nothing special
3184                         $u = false;
3185                 }
3186                 if ( $u ) {
3187                         $u->doUpdate();
3188                 }
3189                 # Update message cache for interface messages
3190                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3191                         # @bug 17860: old article can be deleted, if this the case,
3192                         # delete it from message cache
3193                         if ( $this->getArticleID() === 0 ) {
3194                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3195                         } else {
3196                                 $oldarticle = new Article( $this );
3197                                 MessageCache::singleton()->replace( $this->getDBkey(), $oldarticle->getContent() );
3198                         }
3199                 }
3200                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3201                         $newarticle = new Article( $nt );
3202                         MessageCache::singleton()->replace( $nt->getDBkey(), $newarticle->getContent() );
3203                 }
3204
3205                 global $wgUser;
3206                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3207                 return true;
3208         }
3209
3210         /**
3211          * Move page to a title which is either a redirect to the
3212          * source page or nonexistent
3213          *
3214          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3215          * @param $reason String The reason for the move
3216          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3217          *   if the user doesn't have the suppressredirect right
3218          */
3219         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3220                 global $wgUser, $wgContLang;
3221
3222                 $moveOverRedirect = $nt->exists();
3223
3224                 $commentMsg = ( $moveOverRedirect ? '1movedto2_redir' : '1movedto2' );
3225                 $comment = wfMsgForContent( $commentMsg, $this->getPrefixedText(), $nt->getPrefixedText() );
3226
3227                 if ( $reason ) {
3228                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3229                 }
3230                 # Truncate for whole multibyte characters.
3231                 $comment = $wgContLang->truncate( $comment, 255 );
3232
3233                 $oldid = $this->getArticleID();
3234                 $latest = $this->getLatestRevID();
3235
3236                 $oldns = $this->getNamespace();
3237                 $olddbk = $this->getDBkey();
3238
3239                 $dbw = wfGetDB( DB_MASTER );
3240
3241                 if ( $moveOverRedirect ) {
3242                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3243
3244                         $newid = $nt->getArticleID();
3245                         $newns = $nt->getNamespace();
3246                         $newdbk = $nt->getDBkey();
3247
3248                         # Delete the old redirect. We don't save it to history since
3249                         # by definition if we've got here it's rather uninteresting.
3250                         # We have to remove it so that the next step doesn't trigger
3251                         # a conflict on the unique namespace+title index...
3252                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3253                         if ( !$dbw->cascadingDeletes() ) {
3254                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3255                                 global $wgUseTrackbacks;
3256                                 if ( $wgUseTrackbacks ) {
3257                                         $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3258                                 }
3259                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3260                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3261                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3262                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3263                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3264                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3265                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3266                         }
3267                         // If the target page was recently created, it may have an entry in recentchanges still
3268                         $dbw->delete( 'recentchanges',
3269                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3270                                 __METHOD__
3271                         );
3272                 }
3273
3274                 # Save a null revision in the page's history notifying of the move
3275                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3276                 if ( !is_object( $nullRevision ) ) {
3277                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3278                 }
3279                 $nullRevId = $nullRevision->insertOn( $dbw );
3280
3281                 $article = new Article( $this );
3282                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3283
3284                 # Change the name of the target page:
3285                 $dbw->update( 'page',
3286                         /* SET */ array(
3287                                 'page_touched'   => $dbw->timestamp(),
3288                                 'page_namespace' => $nt->getNamespace(),
3289                                 'page_title'     => $nt->getDBkey(),
3290                                 'page_latest'    => $nullRevId,
3291                         ),
3292                         /* WHERE */ array( 'page_id' => $oldid ),
3293                         __METHOD__
3294                 );
3295                 $nt->resetArticleID( $oldid );
3296
3297                 # Recreate the redirect, this time in the other direction.
3298                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3299                         $mwRedir = MagicWord::get( 'redirect' );
3300                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3301                         $redirectArticle = new Article( $this );
3302                         $newid = $redirectArticle->insertOn( $dbw );
3303                         $redirectRevision = new Revision( array(
3304                                 'page'    => $newid,
3305                                 'comment' => $comment,
3306                                 'text'    => $redirectText ) );
3307                         $redirectRevision->insertOn( $dbw );
3308                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3309
3310                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3311
3312                         # Now, we record the link from the redirect to the new title.
3313                         # It should have no other outgoing links...
3314                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3315                         $dbw->insert( 'pagelinks',
3316                                 array(
3317                                         'pl_from'      => $newid,
3318                                         'pl_namespace' => $nt->getNamespace(),
3319                                         'pl_title'     => $nt->getDBkey() ),
3320                                 __METHOD__ );
3321                         $redirectSuppressed = false;
3322                 } else {
3323                         // Get rid of old new page entries in Special:NewPages and RC.
3324                         // Needs to be before $this->resetArticleID( 0 ).
3325                         $dbw->delete( 'recentchanges', array(
3326                                         'rc_timestamp' => $dbw->timestamp( $this->getEarliestRevTime() ),
3327                                         'rc_namespace' => $oldns,
3328                                         'rc_title' => $olddbk,
3329                                         'rc_new' => 1
3330                                 ),
3331                                 __METHOD__
3332                         );
3333
3334                         $this->resetArticleID( 0 );
3335                         $redirectSuppressed = true;
3336                 }
3337
3338                 # Log the move
3339                 $log = new LogPage( 'move' );
3340                 $logType = ( $moveOverRedirect ? 'move_redir' : 'move' );
3341                 $log->addEntry( $logType, $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3342
3343                 # Purge caches for old and new titles
3344                 if ( $moveOverRedirect ) {
3345                         # A simple purge is enough when moving over a redirect
3346                         $nt->purgeSquid();
3347                 } else {
3348                         # Purge caches as per article creation, including any pages that link to this title
3349                         Article::onArticleCreate( $nt );
3350                 }
3351                 $this->purgeSquid();
3352         }
3353
3354         /**
3355          * Move this page's subpages to be subpages of $nt
3356          *
3357          * @param $nt Title Move target
3358          * @param $auth bool Whether $wgUser's permissions should be checked
3359          * @param $reason string The reason for the move
3360          * @param $createRedirect bool Whether to create redirects from the old subpages to
3361          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3362          * @return mixed array with old page titles as keys, and strings (new page titles) or
3363          *     arrays (errors) as values, or an error array with numeric indices if no pages
3364          *     were moved
3365          */
3366         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3367                 global $wgMaximumMovedPages;
3368                 // Check permissions
3369                 if ( !$this->userCan( 'move-subpages' ) ) {
3370                         return array( 'cant-move-subpages' );
3371                 }
3372                 // Do the source and target namespaces support subpages?
3373                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3374                         return array( 'namespace-nosubpages',
3375                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3376                 }
3377                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3378                         return array( 'namespace-nosubpages',
3379                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3380                 }
3381
3382                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3383                 $retval = array();
3384                 $count = 0;
3385                 foreach ( $subpages as $oldSubpage ) {
3386                         $count++;
3387                         if ( $count > $wgMaximumMovedPages ) {
3388                                 $retval[$oldSubpage->getPrefixedTitle()] =
3389                                                 array( 'movepage-max-pages',
3390                                                         $wgMaximumMovedPages );
3391                                 break;
3392                         }
3393
3394                         // We don't know whether this function was called before
3395                         // or after moving the root page, so check both
3396                         // $this and $nt
3397                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3398                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3399                         {
3400                                 // When moving a page to a subpage of itself,
3401                                 // don't move it twice
3402                                 continue;
3403                         }
3404                         $newPageName = preg_replace(
3405                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3406                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3407                                         $oldSubpage->getDBkey() );
3408                         if ( $oldSubpage->isTalkPage() ) {
3409                                 $newNs = $nt->getTalkPage()->getNamespace();
3410                         } else {
3411                                 $newNs = $nt->getSubjectPage()->getNamespace();
3412                         }
3413                         # Bug 14385: we need makeTitleSafe because the new page names may
3414                         # be longer than 255 characters.
3415                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3416
3417                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3418                         if ( $success === true ) {
3419                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3420                         } else {
3421                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3422                         }
3423                 }
3424                 return $retval;
3425         }
3426
3427         /**
3428          * Checks if this page is just a one-rev redirect.
3429          * Adds lock, so don't use just for light purposes.
3430          *
3431          * @return Bool
3432          */
3433         public function isSingleRevRedirect() {
3434                 $dbw = wfGetDB( DB_MASTER );
3435                 # Is it a redirect?
3436                 $row = $dbw->selectRow( 'page',
3437                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3438                         $this->pageCond(),
3439                         __METHOD__,
3440                         array( 'FOR UPDATE' )
3441                 );
3442                 # Cache some fields we may want
3443                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3444                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3445                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3446                 if ( !$this->mRedirect ) {
3447                         return false;
3448                 }
3449                 # Does the article have a history?
3450                 $row = $dbw->selectField( array( 'page', 'revision' ),
3451                         'rev_id',
3452                         array( 'page_namespace' => $this->getNamespace(),
3453                                 'page_title' => $this->getDBkey(),
3454                                 'page_id=rev_page',
3455                                 'page_latest != rev_id'
3456                         ),
3457                         __METHOD__,
3458                         array( 'FOR UPDATE' )
3459                 );
3460                 # Return true if there was no history
3461                 return ( $row === false );
3462         }
3463
3464         /**
3465          * Checks if $this can be moved to a given Title
3466          * - Selects for update, so don't call it unless you mean business
3467          *
3468          * @param $nt Title the new title to check
3469          * @return Bool
3470          */
3471         public function isValidMoveTarget( $nt ) {
3472                 # Is it an existing file?
3473                 if ( $nt->getNamespace() == NS_FILE ) {
3474                         $file = wfLocalFile( $nt );
3475                         if ( $file->exists() ) {
3476                                 wfDebug( __METHOD__ . ": file exists\n" );
3477                                 return false;
3478                         }
3479                 }
3480                 # Is it a redirect with no history?
3481                 if ( !$nt->isSingleRevRedirect() ) {
3482                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3483                         return false;
3484                 }
3485                 # Get the article text
3486                 $rev = Revision::newFromTitle( $nt );
3487                 $text = $rev->getText();
3488                 # Does the redirect point to the source?
3489                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3490                 $m = array();
3491                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3492                         $redirTitle = Title::newFromText( $m[1] );
3493                         if ( !is_object( $redirTitle ) ||
3494                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3495                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3496                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3497                                 return false;
3498                         }
3499                 } else {
3500                         # Fail safe
3501                         wfDebug( __METHOD__ . ": failsafe\n" );
3502                         return false;
3503                 }
3504                 return true;
3505         }
3506
3507         /**
3508          * Can this title be added to a user's watchlist?
3509          *
3510          * @return Bool TRUE or FALSE
3511          */
3512         public function isWatchable() {
3513                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3514         }
3515
3516         /**
3517          * Get categories to which this Title belongs and return an array of
3518          * categories' names.
3519          *
3520          * @return Array of parents in the form:
3521          *        $parent => $currentarticle
3522          */
3523         public function getParentCategories() {
3524                 global $wgContLang;
3525
3526                 $data = array();
3527
3528                 $titleKey = $this->getArticleId();
3529
3530                 if ( $titleKey === 0 ) {
3531                         return $data;
3532                 }
3533
3534                 $dbr = wfGetDB( DB_SLAVE );
3535
3536                 $res = $dbr->select( 'categorylinks', '*',
3537                         array(
3538                                 'cl_from' => $titleKey,
3539                         ),
3540                         __METHOD__,
3541                         array()
3542                 );
3543
3544                 if ( $dbr->numRows( $res ) > 0 ) {
3545                         foreach ( $res as $row ) {
3546                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3547                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3548                         }
3549                 }
3550                 return $data;
3551         }
3552
3553         /**
3554          * Get a tree of parent categories
3555          *
3556          * @param $children Array with the children in the keys, to check for circular refs
3557          * @return Array Tree of parent categories
3558          */
3559         public function getParentCategoryTree( $children = array() ) {
3560                 $stack = array();
3561                 $parents = $this->getParentCategories();
3562
3563                 if ( $parents ) {
3564                         foreach ( $parents as $parent => $current ) {
3565                                 if ( array_key_exists( $parent, $children ) ) {
3566                                         # Circular reference
3567                                         $stack[$parent] = array();
3568                                 } else {
3569                                         $nt = Title::newFromText( $parent );
3570                                         if ( $nt ) {
3571                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3572                                         }
3573                                 }
3574                         }
3575                 }
3576
3577                 return $stack;
3578         }
3579
3580         /**
3581          * Get an associative array for selecting this title from
3582          * the "page" table
3583          *
3584          * @return Array suitable for the $where parameter of DB::select()
3585          */
3586         public function pageCond() {
3587                 if ( $this->mArticleID > 0 ) {
3588                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3589                         return array( 'page_id' => $this->mArticleID );
3590                 } else {
3591                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3592                 }
3593         }
3594
3595         /**
3596          * Get the revision ID of the previous revision
3597          *
3598          * @param $revId Int Revision ID. Get the revision that was before this one.
3599          * @param $flags Int Title::GAID_FOR_UPDATE
3600          * @return Int|Bool Old revision ID, or FALSE if none exists
3601          */
3602         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3603                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3604                 return $db->selectField( 'revision', 'rev_id',
3605                         array(
3606                                 'rev_page' => $this->getArticleId( $flags ),
3607                                 'rev_id < ' . intval( $revId )
3608                         ),
3609                         __METHOD__,
3610                         array( 'ORDER BY' => 'rev_id DESC' )
3611                 );
3612         }
3613
3614         /**
3615          * Get the revision ID of the next revision
3616          *
3617          * @param $revId Int Revision ID. Get the revision that was after this one.
3618          * @param $flags Int Title::GAID_FOR_UPDATE
3619          * @return Int|Bool Next revision ID, or FALSE if none exists
3620          */
3621         public function getNextRevisionID( $revId, $flags = 0 ) {
3622                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3623                 return $db->selectField( 'revision', 'rev_id',
3624                         array(
3625                                 'rev_page' => $this->getArticleId( $flags ),
3626                                 'rev_id > ' . intval( $revId )
3627                         ),
3628                         __METHOD__,
3629                         array( 'ORDER BY' => 'rev_id' )
3630                 );
3631         }
3632
3633         /**
3634          * Get the first revision of the page
3635          *
3636          * @param $flags Int Title::GAID_FOR_UPDATE
3637          * @return Revision|Null if page doesn't exist
3638          */
3639         public function getFirstRevision( $flags = 0 ) {
3640                 $pageId = $this->getArticleId( $flags );
3641                 if ( $pageId ) {
3642                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3643                         $row = $db->selectRow( 'revision', '*',
3644                                 array( 'rev_page' => $pageId ),
3645                                 __METHOD__,
3646                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3647                         );
3648                         if ( $row ) {
3649                                 return new Revision( $row );
3650                         }
3651                 }
3652                 return null;
3653         }
3654
3655         /**
3656          * Get the oldest revision timestamp of this page
3657          *
3658          * @param $flags Int Title::GAID_FOR_UPDATE
3659          * @return String: MW timestamp
3660          */
3661         public function getEarliestRevTime( $flags = 0 ) {
3662                 $rev = $this->getFirstRevision( $flags );
3663                 return $rev ? $rev->getTimestamp() : null;
3664         }
3665
3666         /**
3667          * Check if this is a new page
3668          *
3669          * @return bool
3670          */
3671         public function isNewPage() {
3672                 $dbr = wfGetDB( DB_SLAVE );
3673                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3674         }
3675
3676         /**
3677          * Get the number of revisions between the given revision.
3678          * Used for diffs and other things that really need it.
3679          *
3680          * @param $old int|Revision Old revision or rev ID (first before range)
3681          * @param $new int|Revision New revision or rev ID (first after range)
3682          * @return Int Number of revisions between these revisions.
3683          */
3684         public function countRevisionsBetween( $old, $new ) {
3685                 if ( !( $old instanceof Revision ) ) {
3686                         $old = Revision::newFromTitle( $this, (int)$old );
3687                 }
3688                 if ( !( $new instanceof Revision ) ) {
3689                         $new = Revision::newFromTitle( $this, (int)$new );
3690                 }
3691                 if ( !$old || !$new ) {
3692                         return 0; // nothing to compare
3693                 }
3694                 $dbr = wfGetDB( DB_SLAVE );
3695                 return (int)$dbr->selectField( 'revision', 'count(*)',
3696                         array(
3697                                 'rev_page' => $this->getArticleId(),
3698                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3699                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3700                         ),
3701                         __METHOD__
3702                 );
3703         }
3704
3705         /**
3706          * Get the number of authors between the given revision IDs.
3707          * Used for diffs and other things that really need it.
3708          *
3709          * @param $old int|Revision Old revision or rev ID (first before range)
3710          * @param $new int|Revision New revision or rev ID (first after range)
3711          * @param $limit Int Maximum number of authors
3712          * @return Int Number of revision authors between these revisions.
3713          */
3714         public function countAuthorsBetween( $old, $new, $limit ) {
3715                 if ( !( $old instanceof Revision ) ) {
3716                         $old = Revision::newFromTitle( $this, (int)$old );
3717                 }
3718                 if ( !( $new instanceof Revision ) ) {
3719                         $new = Revision::newFromTitle( $this, (int)$new );
3720                 }
3721                 if ( !$old || !$new ) {
3722                         return 0; // nothing to compare
3723                 }
3724                 $dbr = wfGetDB( DB_SLAVE );
3725                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
3726                         array(
3727                                 'rev_page' => $this->getArticleID(),
3728                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3729                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3730                         ), __METHOD__,
3731                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
3732                 );
3733                 return (int)$dbr->numRows( $res );
3734         }
3735
3736         /**
3737          * Compare with another title.
3738          *
3739          * @param $title Title
3740          * @return Bool
3741          */
3742         public function equals( Title $title ) {
3743                 // Note: === is necessary for proper matching of number-like titles.
3744                 return $this->getInterwiki() === $title->getInterwiki()
3745                         && $this->getNamespace() == $title->getNamespace()
3746                         && $this->getDBkey() === $title->getDBkey();
3747         }
3748
3749         /**
3750          * Callback for usort() to do title sorts by (namespace, title)
3751          *
3752          * @param $a Title
3753          * @param $b Title
3754          *
3755          * @return Integer: result of string comparison, or namespace comparison
3756          */
3757         public static function compare( $a, $b ) {
3758                 if ( $a->getNamespace() == $b->getNamespace() ) {
3759                         return strcmp( $a->getText(), $b->getText() );
3760                 } else {
3761                         return $a->getNamespace() - $b->getNamespace();
3762                 }
3763         }
3764
3765         /**
3766          * Return a string representation of this title
3767          *
3768          * @return String representation of this title
3769          */
3770         public function __toString() {
3771                 return $this->getPrefixedText();
3772         }
3773
3774         /**
3775          * Check if page exists.  For historical reasons, this function simply
3776          * checks for the existence of the title in the page table, and will
3777          * thus return false for interwiki links, special pages and the like.
3778          * If you want to know if a title can be meaningfully viewed, you should
3779          * probably call the isKnown() method instead.
3780          *
3781          * @return Bool
3782          */
3783         public function exists() {
3784                 return $this->getArticleId() != 0;
3785         }
3786
3787         /**
3788          * Should links to this title be shown as potentially viewable (i.e. as
3789          * "bluelinks"), even if there's no record by this title in the page
3790          * table?
3791          *
3792          * This function is semi-deprecated for public use, as well as somewhat
3793          * misleadingly named.  You probably just want to call isKnown(), which
3794          * calls this function internally.
3795          *
3796          * (ISSUE: Most of these checks are cheap, but the file existence check
3797          * can potentially be quite expensive.  Including it here fixes a lot of
3798          * existing code, but we might want to add an optional parameter to skip
3799          * it and any other expensive checks.)
3800          *
3801          * @return Bool
3802          */
3803         public function isAlwaysKnown() {
3804                 if ( $this->mInterwiki != '' ) {
3805                         return true;  // any interwiki link might be viewable, for all we know
3806                 }
3807                 switch( $this->mNamespace ) {
3808                         case NS_MEDIA:
3809                         case NS_FILE:
3810                                 // file exists, possibly in a foreign repo
3811                                 return (bool)wfFindFile( $this );
3812                         case NS_SPECIAL:
3813                                 // valid special page
3814                                 return SpecialPageFactory::exists( $this->getDBkey() );
3815                         case NS_MAIN:
3816                                 // selflink, possibly with fragment
3817                                 return $this->mDbkeyform == '';
3818                         case NS_MEDIAWIKI:
3819                                 // known system message
3820                                 return $this->getDefaultMessageText() !== false;
3821                         default:
3822                                 return false;
3823                 }
3824         }
3825
3826         /**
3827          * Does this title refer to a page that can (or might) be meaningfully
3828          * viewed?  In particular, this function may be used to determine if
3829          * links to the title should be rendered as "bluelinks" (as opposed to
3830          * "redlinks" to non-existent pages).
3831          *
3832          * @return Bool
3833          */
3834         public function isKnown() {
3835                 return $this->isAlwaysKnown() || $this->exists();
3836         }
3837
3838         /**
3839          * Does this page have source text?
3840          *
3841          * @return Boolean
3842          */
3843         public function hasSourceText() {
3844                 if ( $this->exists() ) {
3845                         return true;
3846                 }
3847
3848                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3849                         // If the page doesn't exist but is a known system message, default
3850                         // message content will be displayed, same for language subpages
3851                         return $this->getDefaultMessageText() !== false;
3852                 }
3853
3854                 return false;
3855         }
3856
3857         /**
3858          * Get the default message text or false if the message doesn't exist
3859          *
3860          * @return String or false
3861          */
3862         public function getDefaultMessageText() {
3863                 global $wgContLang;
3864
3865                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
3866                         return false;
3867                 }
3868
3869                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
3870                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
3871
3872                 if ( $message->exists() ) {
3873                         return $message->plain();
3874                 } else {
3875                         return false;
3876                 }
3877         }
3878
3879         /**
3880          * Is this in a namespace that allows actual pages?
3881          *
3882          * @return Bool
3883          * @internal note -- uses hardcoded namespace index instead of constants
3884          */
3885         public function canExist() {
3886                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3887         }
3888
3889         /**
3890          * Update page_touched timestamps and send squid purge messages for
3891          * pages linking to this title. May be sent to the job queue depending
3892          * on the number of links. Typically called on create and delete.
3893          */
3894         public function touchLinks() {
3895                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3896                 $u->doUpdate();
3897
3898                 if ( $this->getNamespace() == NS_CATEGORY ) {
3899                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3900                         $u->doUpdate();
3901                 }
3902         }
3903
3904         /**
3905          * Get the last touched timestamp
3906          *
3907          * @param $db DatabaseBase: optional db
3908          * @return String last-touched timestamp
3909          */
3910         public function getTouched( $db = null ) {
3911                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3912                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3913                 return $touched;
3914         }
3915
3916         /**
3917          * Get the timestamp when this page was updated since the user last saw it.
3918          *
3919          * @param $user User
3920          * @return String|Null
3921          */
3922         public function getNotificationTimestamp( $user = null ) {
3923                 global $wgUser, $wgShowUpdatedMarker;
3924                 // Assume current user if none given
3925                 if ( !$user ) {
3926                         $user = $wgUser;
3927                 }
3928                 // Check cache first
3929                 $uid = $user->getId();
3930                 // avoid isset here, as it'll return false for null entries
3931                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
3932                         return $this->mNotificationTimestamp[$uid];
3933                 }
3934                 if ( !$uid || !$wgShowUpdatedMarker ) {
3935                         return $this->mNotificationTimestamp[$uid] = false;
3936                 }
3937                 // Don't cache too much!
3938                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3939                         $this->mNotificationTimestamp = array();
3940                 }
3941                 $dbr = wfGetDB( DB_SLAVE );
3942                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3943                         'wl_notificationtimestamp',
3944                         array( 'wl_namespace' => $this->getNamespace(),
3945                                 'wl_title' => $this->getDBkey(),
3946                                 'wl_user' => $user->getId()
3947                         ),
3948                         __METHOD__
3949                 );
3950                 return $this->mNotificationTimestamp[$uid];
3951         }
3952
3953         /**
3954          * Get the trackback URL for this page
3955          *
3956          * @return String Trackback URL
3957          */
3958         public function trackbackURL() {
3959                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3960
3961                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3962                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3963         }
3964
3965         /**
3966          * Get the trackback RDF for this page
3967          *
3968          * @return String Trackback RDF
3969          */
3970         public function trackbackRDF() {
3971                 $url = htmlspecialchars( $this->getFullURL() );
3972                 $title = htmlspecialchars( $this->getText() );
3973                 $tburl = $this->trackbackURL();
3974
3975                 // Autodiscovery RDF is placed in comments so HTML validator
3976                 // won't barf. This is a rather icky workaround, but seems
3977                 // frequently used by this kind of RDF thingy.
3978                 //
3979                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3980                 return "<!--
3981 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3982                  xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3983                  xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3984 <rdf:Description
3985    rdf:about=\"$url\"
3986    dc:identifier=\"$url\"
3987    dc:title=\"$title\"
3988    trackback:ping=\"$tburl\" />
3989 </rdf:RDF>
3990 -->";
3991         }
3992
3993         /**
3994          * Generate strings used for xml 'id' names in monobook tabs
3995          *
3996          * @param $prepend string defaults to 'nstab-'
3997          * @return String XML 'id' name
3998          */
3999         public function getNamespaceKey( $prepend = 'nstab-' ) {
4000                 global $wgContLang;
4001                 // Gets the subject namespace if this title
4002                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4003                 // Checks if cononical namespace name exists for namespace
4004                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4005                         // Uses canonical namespace name
4006                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4007                 } else {
4008                         // Uses text of namespace
4009                         $namespaceKey = $this->getSubjectNsText();
4010                 }
4011                 // Makes namespace key lowercase
4012                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4013                 // Uses main
4014                 if ( $namespaceKey == '' ) {
4015                         $namespaceKey = 'main';
4016                 }
4017                 // Changes file to image for backwards compatibility
4018                 if ( $namespaceKey == 'file' ) {
4019                         $namespaceKey = 'image';
4020                 }
4021                 return $prepend . $namespaceKey;
4022         }
4023
4024         /**
4025          * Returns true if this is a special page.
4026          *
4027          * @return boolean
4028          */
4029         public function isSpecialPage() {
4030                 return $this->getNamespace() == NS_SPECIAL;
4031         }
4032
4033         /**
4034          * Returns true if this title resolves to the named special page
4035          *
4036          * @param $name String The special page name
4037          * @return boolean
4038          */
4039         public function isSpecial( $name ) {
4040                 if ( $this->getNamespace() == NS_SPECIAL ) {
4041                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
4042                         if ( $name == $thisName ) {
4043                                 return true;
4044                         }
4045                 }
4046                 return false;
4047         }
4048
4049         /**
4050          * If the Title refers to a special page alias which is not the local default, resolve
4051          * the alias, and localise the name as necessary.  Otherwise, return $this
4052          *
4053          * @return Title
4054          */
4055         public function fixSpecialName() {
4056                 if ( $this->getNamespace() == NS_SPECIAL ) {
4057                         list( $canonicalName, /*...*/ ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
4058                         if ( $canonicalName ) {
4059                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName );
4060                                 if ( $localName != $this->mDbkeyform ) {
4061                                         return Title::makeTitle( NS_SPECIAL, $localName );
4062                                 }
4063                         }
4064                 }
4065                 return $this;
4066         }
4067
4068         /**
4069          * Is this Title in a namespace which contains content?
4070          * In other words, is this a content page, for the purposes of calculating
4071          * statistics, etc?
4072          *
4073          * @return Boolean
4074          */
4075         public function isContentPage() {
4076                 return MWNamespace::isContent( $this->getNamespace() );
4077         }
4078
4079         /**
4080          * Get all extant redirects to this Title
4081          *
4082          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4083          * @return Array of Title redirects to this title
4084          */
4085         public function getRedirectsHere( $ns = null ) {
4086                 $redirs = array();
4087
4088                 $dbr = wfGetDB( DB_SLAVE );
4089                 $where = array(
4090                         'rd_namespace' => $this->getNamespace(),
4091                         'rd_title' => $this->getDBkey(),
4092                         'rd_from = page_id'
4093                 );
4094                 if ( !is_null( $ns ) ) {
4095                         $where['page_namespace'] = $ns;
4096                 }
4097
4098                 $res = $dbr->select(
4099                         array( 'redirect', 'page' ),
4100                         array( 'page_namespace', 'page_title' ),
4101                         $where,
4102                         __METHOD__
4103                 );
4104
4105                 foreach ( $res as $row ) {
4106                         $redirs[] = self::newFromRow( $row );
4107                 }
4108                 return $redirs;
4109         }
4110
4111         /**
4112          * Check if this Title is a valid redirect target
4113          *
4114          * @return Bool
4115          */
4116         public function isValidRedirectTarget() {
4117                 global $wgInvalidRedirectTargets;
4118
4119                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4120                 if ( $this->isSpecial( 'Userlogout' ) ) {
4121                         return false;
4122                 }
4123
4124                 foreach ( $wgInvalidRedirectTargets as $target ) {
4125                         if ( $this->isSpecial( $target ) ) {
4126                                 return false;
4127                         }
4128                 }
4129
4130                 return true;
4131         }
4132
4133         /**
4134          * Get a backlink cache object
4135          *
4136          * @return object BacklinkCache
4137          */
4138         function getBacklinkCache() {
4139                 if ( is_null( $this->mBacklinkCache ) ) {
4140                         $this->mBacklinkCache = new BacklinkCache( $this );
4141                 }
4142                 return $this->mBacklinkCache;
4143         }
4144
4145         /**
4146          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4147          *
4148          * @return Boolean
4149          */
4150         public function canUseNoindex() {
4151                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4152
4153                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4154                         ? $wgContentNamespaces
4155                         : $wgExemptFromUserRobotsControl;
4156
4157                 return !in_array( $this->mNamespace, $bannedNamespaces );
4158
4159         }
4160
4161         /**
4162          * Returns restriction types for the current Title
4163          *
4164          * @return array applicable restriction types
4165          */
4166         public function getRestrictionTypes() {
4167                 if ( $this->getNamespace() == NS_SPECIAL ) {
4168                         return array();
4169                 }
4170
4171                 $types = self::getFilteredRestrictionTypes( $this->exists() );
4172
4173                 if ( $this->getNamespace() != NS_FILE ) {
4174                         # Remove the upload restriction for non-file titles
4175                         $types = array_diff( $types, array( 'upload' ) );
4176                 }
4177
4178                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4179
4180                 wfDebug( __METHOD__ . ': applicable restriction types for ' .
4181                         $this->getPrefixedText() . ' are ' . implode( ',', $types ) . "\n" );
4182
4183                 return $types;
4184         }
4185         /**
4186          * Get a filtered list of all restriction types supported by this wiki.
4187          * @param bool $exists True to get all restriction types that apply to
4188          * titles that do exist, False for all restriction types that apply to
4189          * titles that do not exist
4190          * @return array
4191          */
4192         public static function getFilteredRestrictionTypes( $exists = true ) {
4193                 global $wgRestrictionTypes;
4194                 $types = $wgRestrictionTypes;
4195                 if ( $exists ) {
4196                         # Remove the create restriction for existing titles
4197                         $types = array_diff( $types, array( 'create' ) );
4198                 } else {
4199                         # Only the create and upload restrictions apply to non-existing titles
4200                         $types = array_intersect( $types, array( 'create', 'upload' ) );
4201                 }
4202                 return $types;
4203         }
4204
4205         /**
4206          * Returns the raw sort key to be used for categories, with the specified
4207          * prefix.  This will be fed to Collation::getSortKey() to get a
4208          * binary sortkey that can be used for actual sorting.
4209          *
4210          * @param $prefix string The prefix to be used, specified using
4211          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4212          *   prefix.
4213          * @return string
4214          */
4215         public function getCategorySortkey( $prefix = '' ) {
4216                 $unprefixed = $this->getText();
4217                 if ( $prefix !== '' ) {
4218                         # Separate with a line feed, so the unprefixed part is only used as
4219                         # a tiebreaker when two pages have the exact same prefix.
4220                         # In UCA, tab is the only character that can sort above LF
4221                         # so we strip both of them from the original prefix.
4222                         $prefix = strtr( $prefix, "\n\t", '  ' );
4223                         return "$prefix\n$unprefixed";
4224                 }
4225                 return $unprefixed;
4226         }
4227 }
4228
4229 /**
4230  * A BadTitle is generated in MediaWiki::parseTitle() if the title is invalid; the
4231  * software uses this to display an error page.  Internally it's basically a Title
4232  * for an empty special page
4233  */
4234 class BadTitle extends Title {
4235         public function __construct(){
4236                 $this->mTextform = '';
4237                 $this->mUrlform = '';
4238                 $this->mDbkeyform = '';
4239                 $this->mNamespace = NS_SPECIAL; // Stops talk page link, etc, being shown
4240         }
4241
4242         public function exists(){
4243                 return false;
4244         }
4245
4246         public function getPrefixedText(){
4247                 return '';
4248         }
4249
4250         public function getText(){
4251                 return '';
4252         }
4253
4254         public function getPrefixedURL(){
4255                 return '';
4256         }
4257
4258         public function getPrefixedDBKey(){
4259                 return '';
4260         }
4261 }