includes/Title.php

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