includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  * @file
   5  */
   6
   7 /**
   8  * Represents a title within MediaWiki.
   9  * Optionally may contain an interwiki designation or namespace.
  10  * @note This class can fetch various kinds of data from the database;
  11  *       however, it does so inefficiently.
  12  *
  13  * @internal documentation reviewed 15 Mar 2010
  14  */
  15 class Title {
  16         /** @name Static cache variables */
  17         // @{
  18         static private $titleCache = array();
  19         // @}
  20
  21         /**
  22          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  23          * commonly used titles. On a batch operation this can become a memory leak
  24          * if not bounded. After hitting this many titles reset the cache.
  25          */
  26         const CACHE_MAX = 1000;
  27
  28         /**
  29          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  30          * to use the master DB
  31          */
  32         const GAID_FOR_UPDATE = 1;
  33
  34
  35         /**
  36          * @name Private member variables
  37          * Please use the accessor functions instead.
  38          * @private
  39          */
  40         // @{
  41
  42         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  43         var $mUrlform = '';               // /< URL-encoded form of the main part
  44         var $mDbkeyform = '';             // /< Main part with underscores
  45         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  46         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  47         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  48         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  49         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  50         var $mLatestID = false;           // /< ID of most recent revision
  51         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  52         var $mOldRestrictions = false;
  53         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  54         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  55         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  56         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  57         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  58         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  59         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  60         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  61         # Don't change the following default, NS_MAIN is hardcoded in several
  62         # places.  See bug 696.
  63         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  64                                                                           # Zero except in {{transclusion}} tags
  65         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  66         var $mLength = -1;                // /< The page length, 0 for special pages
  67         var $mRedirect = null;            // /< Is the article at this title a redirect?
  68         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  69         var $mBacklinkCache = null;       // /< Cache of links to this title
  70         // @}
  71
  72
  73         /**
  74          * Constructor
  75          */
  76         /*protected*/ function __construct() { }
  77
  78         /**
  79          * Create a new Title from a prefixed DB key
  80          *
  81          * @param $key String the database key, which has underscores
  82          *      instead of spaces, possibly including namespace and
  83          *      interwiki prefixes
  84          * @return Title, or NULL on an error
  85          */
  86         public static function newFromDBkey( $key ) {
  87                 $t = new Title();
  88                 $t->mDbkeyform = $key;
  89                 if ( $t->secureAndSplit() ) {
  90                         return $t;
  91                 } else {
  92                         return null;
  93                 }
  94         }
  95
  96         /**
  97          * Create a new Title from text, such as what one would find in a link. De-
  98          * codes any HTML entities in the text.
  99          *
 100          * @param $text String the link text; spaces, prefixes, and an
 101          *   initial ':' indicating the main namespace are accepted.
 102          * @param $defaultNamespace Int the namespace to use if none is speci-
 103          *   fied by a prefix.  If you want to force a specific namespace even if
 104          *   $text might begin with a namespace prefix, use makeTitle() or
 105          *   makeTitleSafe().
 106          * @return Title, or null on an error.
 107          */
 108         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 109                 if ( is_object( $text ) ) {
 110                         throw new MWException( 'Title::newFromText given an object' );
 111                 }
 112
 113                 /**
 114                  * Wiki pages often contain multiple links to the same page.
 115                  * Title normalization and parsing can become expensive on
 116                  * pages with many links, so we can save a little time by
 117                  * caching them.
 118                  *
 119                  * In theory these are value objects and won't get changed...
 120                  */
 121                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 122                         return Title::$titleCache[$text];
 123                 }
 124
 125                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 126                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 127
 128                 $t = new Title();
 129                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 130                 $t->mDefaultNamespace = $defaultNamespace;
 131
 132                 static $cachedcount = 0 ;
 133                 if ( $t->secureAndSplit() ) {
 134                         if ( $defaultNamespace == NS_MAIN ) {
 135                                 if ( $cachedcount >= self::CACHE_MAX ) {
 136                                         # Avoid memory leaks on mass operations...
 137                                         Title::$titleCache = array();
 138                                         $cachedcount = 0;
 139                                 }
 140                                 $cachedcount++;
 141                                 Title::$titleCache[$text] =& $t;
 142                         }
 143                         return $t;
 144                 } else {
 145                         $ret = null;
 146                         return $ret;
 147                 }
 148         }
 149
 150         /**
 151          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 152          *
 153          * Example of wrong and broken code:
 154          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 155          *
 156          * Example of right code:
 157          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 158          *
 159          * Create a new Title from URL-encoded text. Ensures that
 160          * the given title's length does not exceed the maximum.
 161          *
 162          * @param $url String the title, as might be taken from a URL
 163          * @return Title the new object, or NULL on an error
 164          */
 165         public static function newFromURL( $url ) {
 166                 global $wgLegalTitleChars;
 167                 $t = new Title();
 168
 169                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 170                 # but some URLs used it as a space replacement and they still come
 171                 # from some external search tools.
 172                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 173                         $url = str_replace( '+', ' ', $url );
 174                 }
 175
 176                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 177                 if ( $t->secureAndSplit() ) {
 178                         return $t;
 179                 } else {
 180                         return null;
 181                 }
 182         }
 183
 184         /**
 185          * Create a new Title from an article ID
 186          *
 187          * @param $id Int the page_id corresponding to the Title to create
 188          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 189          * @return Title the new object, or NULL on an error
 190          */
 191         public static function newFromID( $id, $flags = 0 ) {
 192                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 193                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 194                 if ( $row !== false ) {
 195                         $title = Title::newFromRow( $row );
 196                 } else {
 197                         $title = null;
 198                 }
 199                 return $title;
 200         }
 201
 202         /**
 203          * Make an array of titles from an array of IDs
 204          *
 205          * @param $ids Array of Int Array of IDs
 206          * @return Array of Titles
 207          */
 208         public static function newFromIDs( $ids ) {
 209                 if ( !count( $ids ) ) {
 210                         return array();
 211                 }
 212                 $dbr = wfGetDB( DB_SLAVE );
 213
 214                 $res = $dbr->select(
 215                         'page',
 216                         array(
 217                                 'page_namespace', 'page_title', 'page_id',
 218                                 'page_len', 'page_is_redirect', 'page_latest',
 219                         ),
 220                         array( 'page_id' => $ids ),
 221                         __METHOD__
 222                 );
 223
 224                 $titles = array();
 225                 foreach ( $res as $row ) {
 226                         $titles[] = Title::newFromRow( $row );
 227                 }
 228                 return $titles;
 229         }
 230
 231         /**
 232          * Make a Title object from a DB row
 233          *
 234          * @param $row Object database row (needs at least page_title,page_namespace)
 235          * @return Title corresponding Title
 236          */
 237         public static function newFromRow( $row ) {
 238                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 239
 240                 $t->mArticleID = isset( $row->page_id ) ? intval( $row->page_id ) : -1;
 241                 $t->mLength = isset( $row->page_len ) ? intval( $row->page_len ) : -1;
 242                 $t->mRedirect = isset( $row->page_is_redirect ) ? (bool)$row->page_is_redirect : null;
 243                 $t->mLatestID = isset( $row->page_latest ) ? intval( $row->page_latest ) : false;
 244
 245                 return $t;
 246         }
 247
 248         /**
 249          * Create a new Title from a namespace index and a DB key.
 250          * It's assumed that $ns and $title are *valid*, for instance when
 251          * they came directly from the database or a special page name.
 252          * For convenience, spaces are converted to underscores so that
 253          * eg user_text fields can be used directly.
 254          *
 255          * @param $ns Int the namespace of the article
 256          * @param $title String the unprefixed database key form
 257          * @param $fragment String the link fragment (after the "#")
 258          * @param $interwiki String the interwiki prefix
 259          * @return Title the new object
 260          */
 261         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 262                 $t = new Title();
 263                 $t->mInterwiki = $interwiki;
 264                 $t->mFragment = $fragment;
 265                 $t->mNamespace = $ns = intval( $ns );
 266                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 267                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 268                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 269                 $t->mTextform = str_replace( '_', ' ', $title );
 270                 return $t;
 271         }
 272
 273         /**
 274          * Create a new Title from a namespace index and a DB key.
 275          * The parameters will be checked for validity, which is a bit slower
 276          * than makeTitle() but safer for user-provided data.
 277          *
 278          * @param $ns Int the namespace of the article
 279          * @param $title String database key form
 280          * @param $fragment String the link fragment (after the "#")
 281          * @param $interwiki String interwiki prefix
 282          * @return Title the new object, or NULL on an error
 283          */
 284         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 285                 $t = new Title();
 286                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 287                 if ( $t->secureAndSplit() ) {
 288                         return $t;
 289                 } else {
 290                         return null;
 291                 }
 292         }
 293
 294         /**
 295          * Create a new Title for the Main Page
 296          *
 297          * @return Title the new object
 298          */
 299         public static function newMainPage() {
 300                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 301                 // Don't give fatal errors if the message is broken
 302                 if ( !$title ) {
 303                         $title = Title::newFromText( 'Main Page' );
 304                 }
 305                 return $title;
 306         }
 307
 308         /**
 309          * Extract a redirect destination from a string and return the
 310          * Title, or null if the text doesn't contain a valid redirect
 311          * This will only return the very next target, useful for
 312          * the redirect table and other checks that don't need full recursion
 313          *
 314          * @param $text String: Text with possible redirect
 315          * @return Title: The corresponding Title
 316          */
 317         public static function newFromRedirect( $text ) {
 318                 return self::newFromRedirectInternal( $text );
 319         }
 320
 321         /**
 322          * Extract a redirect destination from a string and return the
 323          * Title, or null if the text doesn't contain a valid redirect
 324          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 325          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 326          *
 327          * @param $text String Text with possible redirect
 328          * @return Title
 329          */
 330         public static function newFromRedirectRecurse( $text ) {
 331                 $titles = self::newFromRedirectArray( $text );
 332                 return $titles ? array_pop( $titles ) : null;
 333         }
 334
 335         /**
 336          * Extract a redirect destination from a string and return an
 337          * array of Titles, or null if the text doesn't contain a valid redirect
 338          * The last element in the array is the final destination after all redirects
 339          * have been resolved (up to $wgMaxRedirects times)
 340          *
 341          * @param $text String Text with possible redirect
 342          * @return Array of Titles, with the destination last
 343          */
 344         public static function newFromRedirectArray( $text ) {
 345                 global $wgMaxRedirects;
 346                 $title = self::newFromRedirectInternal( $text );
 347                 if ( is_null( $title ) ) {
 348                         return null;
 349                 }
 350                 // recursive check to follow double redirects
 351                 $recurse = $wgMaxRedirects;
 352                 $titles = array( $title );
 353                 while ( --$recurse > 0 ) {
 354                         if ( $title->isRedirect() ) {
 355                                 $article = new Article( $title, 0 );
 356                                 $newtitle = $article->getRedirectTarget();
 357                         } else {
 358                                 break;
 359                         }
 360                         // Redirects to some special pages are not permitted
 361                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 362                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 363                                 $title = $newtitle;
 364                                 $titles[] = $newtitle;
 365                         } else {
 366                                 break;
 367                         }
 368                 }
 369                 return $titles;
 370         }
 371
 372         /**
 373          * Really extract the redirect destination
 374          * Do not call this function directly, use one of the newFromRedirect* functions above
 375          *
 376          * @param $text String Text with possible redirect
 377          * @return Title
 378          */
 379         protected static function newFromRedirectInternal( $text ) {
 380                 global $wgMaxRedirects;
 381                 if ( $wgMaxRedirects < 1 ) {
 382                         //redirects are disabled, so quit early
 383                         return null;
 384                 }
 385                 $redir = MagicWord::get( 'redirect' );
 386                 $text = trim( $text );
 387                 if ( $redir->matchStartAndRemove( $text ) ) {
 388                         // Extract the first link and see if it's usable
 389                         // Ensure that it really does come directly after #REDIRECT
 390                         // Some older redirects included a colon, so don't freak about that!
 391                         $m = array();
 392                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 393                                 // Strip preceding colon used to "escape" categories, etc.
 394                                 // and URL-decode links
 395                                 if ( strpos( $m[1], '%' ) !== false ) {
 396                                         // Match behavior of inline link parsing here;
 397                                         $m[1] = rawurldecode( 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 Int the page_id of the article
 418          * @return Title an object representing the article, or NULL if no such article was found
 419          */
 420         public static function nameOf( $id ) {
 421                 $dbr = wfGetDB( DB_SLAVE );
 422
 423                 $s = $dbr->selectRow(
 424                         'page',
 425                         array( 'page_namespace', 'page_title' ),
 426                         array( 'page_id' => $id ),
 427                         __METHOD__
 428                 );
 429                 if ( $s === false ) {
 430                         return null;
 431                 }
 432
 433                 $n = self::makeName( $s->page_namespace, $s->page_title );
 434                 return $n;
 435         }
 436
 437         /**
 438          * Get a regex character class describing the legal characters in a link
 439          *
 440          * @return String the list of characters, not delimited
 441          */
 442         public static function legalChars() {
 443                 global $wgLegalTitleChars;
 444                 return $wgLegalTitleChars;
 445         }
 446
 447         /**
 448          * Get a string representation of a title suitable for
 449          * including in a search index
 450          *
 451          * @param $ns Int a namespace index
 452          * @param $title String text-form main part
 453          * @return String a stripped-down title string ready for the search index
 454          */
 455         public static function indexTitle( $ns, $title ) {
 456                 global $wgContLang;
 457
 458                 $lc = SearchEngine::legalSearchChars() . '&#;';
 459                 $t = $wgContLang->normalizeForSearch( $title );
 460                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 461                 $t = $wgContLang->lc( $t );
 462
 463                 # Handle 's, s'
 464                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 465                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 466
 467                 $t = preg_replace( "/\\s+/", ' ', $t );
 468
 469                 if ( $ns == NS_FILE ) {
 470                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 471                 }
 472                 return trim( $t );
 473         }
 474
 475         /**
 476          * Make a prefixed DB key from a DB key and a namespace index
 477          *
 478          * @param $ns Int numerical representation of the namespace
 479          * @param $title String the DB key form the title
 480          * @param $fragment String The link fragment (after the "#")
 481          * @param $interwiki String The interwiki prefix
 482          * @return String the prefixed form of the title
 483          */
 484         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 485                 global $wgContLang;
 486
 487                 $namespace = $wgContLang->getNsText( $ns );
 488                 $name = $namespace == '' ? $title : "$namespace:$title";
 489                 if ( strval( $interwiki ) != '' ) {
 490                         $name = "$interwiki:$name";
 491                 }
 492                 if ( strval( $fragment ) != '' ) {
 493                         $name .= '#' . $fragment;
 494                 }
 495                 return $name;
 496         }
 497
 498         /**
 499          * Determine whether the object refers to a page within
 500          * this project.
 501          *
 502          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 503          */
 504         public function isLocal() {
 505                 if ( $this->mInterwiki != '' ) {
 506                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 507                 } else {
 508                         return true;
 509                 }
 510         }
 511
 512         /**
 513          * Determine whether the object refers to a page within
 514          * this project and is transcludable.
 515          *
 516          * @return Bool TRUE if this is transcludable
 517          */
 518         public function isTrans() {
 519                 if ( $this->mInterwiki == '' ) {
 520                         return false;
 521                 }
 522
 523                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 524         }
 525
 526         /**
 527          * Returns the DB name of the distant wiki which owns the object.
 528          *
 529          * @return String the DB name
 530          */
 531         public function getTransWikiID() {
 532                 if ( $this->mInterwiki == '' ) {
 533                         return false;
 534                 }
 535
 536                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 537         }
 538
 539         /**
 540          * Escape a text fragment, say from a link, for a URL
 541          *
 542          * @param $fragment string containing a URL or link fragment (after the "#")
 543          * @return String: escaped string
 544          */
 545         static function escapeFragmentForURL( $fragment ) {
 546                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 547                 # fragments appear not to work in IE (at least up to 7) or in at least
 548                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 549                 # to care if they aren't encoded.
 550                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 551         }
 552
 553 # ----------------------------------------------------------------------------
 554 #       Other stuff
 555 # ----------------------------------------------------------------------------
 556
 557         /** Simple accessors */
 558         /**
 559          * Get the text form (spaces not underscores) of the main part
 560          *
 561          * @return String Main part of the title
 562          */
 563         public function getText() { return $this->mTextform; }
 564
 565         /**
 566          * Get the URL-encoded form of the main part
 567          *
 568          * @return String Main part of the title, URL-encoded
 569          */
 570         public function getPartialURL() { return $this->mUrlform; }
 571
 572         /**
 573          * Get the main part with underscores
 574          *
 575          * @return String: Main part of the title, with underscores
 576          */
 577         public function getDBkey() { return $this->mDbkeyform; }
 578
 579         /**
 580          * Get the namespace index, i.e. one of the NS_xxxx constants.
 581          *
 582          * @return Integer: Namespace index
 583          */
 584         public function getNamespace() { return $this->mNamespace; }
 585
 586         /**
 587          * Get the namespace text
 588          *
 589          * @return String: Namespace text
 590          */
 591         public function getNsText() {
 592                 global $wgContLang;
 593
 594                 if ( $this->mInterwiki != '' ) {
 595                         // This probably shouldn't even happen. ohh man, oh yuck.
 596                         // But for interwiki transclusion it sometimes does.
 597                         // Shit. Shit shit shit.
 598                         //
 599                         // Use the canonical namespaces if possible to try to
 600                         // resolve a foreign namespace.
 601                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 602                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 603                         }
 604                 }
 605
 606                 if ( $wgContLang->needsGenderDistinction() &&
 607                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 608                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 609                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 610                 }
 611
 612                 return $wgContLang->getNsText( $this->mNamespace );
 613         }
 614
 615         /**
 616          * Get the DB key with the initial letter case as specified by the user
 617          *
 618          * @return String DB key
 619          */
 620         function getUserCaseDBKey() {
 621                 return $this->mUserCaseDBKey;
 622         }
 623
 624         /**
 625          * Get the namespace text of the subject (rather than talk) page
 626          *
 627          * @return String Namespace text
 628          */
 629         public function getSubjectNsText() {
 630                 global $wgContLang;
 631                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 632         }
 633
 634         /**
 635          * Get the namespace text of the talk page
 636          *
 637          * @return String Namespace text
 638          */
 639         public function getTalkNsText() {
 640                 global $wgContLang;
 641                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 642         }
 643
 644         /**
 645          * Could this title have a corresponding talk page?
 646          *
 647          * @return Bool TRUE or FALSE
 648          */
 649         public function canTalk() {
 650                 return( MWNamespace::canTalk( $this->mNamespace ) );
 651         }
 652
 653         /**
 654          * Get the interwiki prefix (or null string)
 655          *
 656          * @return String Interwiki prefix
 657          */
 658         public function getInterwiki() { return $this->mInterwiki; }
 659
 660         /**
 661          * Get the Title fragment (i.e.\ the bit after the #) in text form
 662          *
 663          * @return String Title fragment
 664          */
 665         public function getFragment() { return $this->mFragment; }
 666
 667         /**
 668          * Get the fragment in URL form, including the "#" character if there is one
 669          * @return String Fragment in URL form
 670          */
 671         public function getFragmentForURL() {
 672                 if ( $this->mFragment == '' ) {
 673                         return '';
 674                 } else {
 675                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 676                 }
 677         }
 678
 679         /**
 680          * Get the default namespace index, for when there is no namespace
 681          *
 682          * @return Int Default namespace index
 683          */
 684         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 685
 686         /**
 687          * Get title for search index
 688          *
 689          * @return String a stripped-down title string ready for the
 690          *  search index
 691          */
 692         public function getIndexTitle() {
 693                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 694         }
 695
 696         /**
 697          * Get the prefixed database key form
 698          *
 699          * @return String the prefixed title, with underscores and
 700          *  any interwiki and namespace prefixes
 701          */
 702         public function getPrefixedDBkey() {
 703                 $s = $this->prefix( $this->mDbkeyform );
 704                 $s = str_replace( ' ', '_', $s );
 705                 return $s;
 706         }
 707
 708         /**
 709          * Get the prefixed title with spaces.
 710          * This is the form usually used for display
 711          *
 712          * @return String the prefixed title, with spaces
 713          */
 714         public function getPrefixedText() {
 715                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 716                         $s = $this->prefix( $this->mTextform );
 717                         $s = str_replace( '_', ' ', $s );
 718                         $this->mPrefixedText = $s;
 719                 }
 720                 return $this->mPrefixedText;
 721         }
 722
 723         /**
 724          * Get the prefixed title with spaces, plus any fragment
 725          * (part beginning with '#')
 726          *
 727          * @return String the prefixed title, with spaces and the fragment, including '#'
 728          */
 729         public function getFullText() {
 730                 $text = $this->getPrefixedText();
 731                 if ( $this->mFragment != '' ) {
 732                         $text .= '#' . $this->mFragment;
 733                 }
 734                 return $text;
 735         }
 736
 737         /**
 738          * Get the base name, i.e. the leftmost parts before the /
 739          *
 740          * @return String Base name
 741          */
 742         public function getBaseText() {
 743                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 744                         return $this->getText();
 745                 }
 746
 747                 $parts = explode( '/', $this->getText() );
 748                 # Don't discard the real title if there's no subpage involved
 749                 if ( count( $parts ) > 1 ) {
 750                         unset( $parts[count( $parts ) - 1] );
 751                 }
 752                 return implode( '/', $parts );
 753         }
 754
 755         /**
 756          * Get the lowest-level subpage name, i.e. the rightmost part after /
 757          *
 758          * @return String Subpage name
 759          */
 760         public function getSubpageText() {
 761                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 762                         return( $this->mTextform );
 763                 }
 764                 $parts = explode( '/', $this->mTextform );
 765                 return( $parts[count( $parts ) - 1] );
 766         }
 767
 768         /**
 769          * Get a URL-encoded form of the subpage text
 770          *
 771          * @return String URL-encoded subpage name
 772          */
 773         public function getSubpageUrlForm() {
 774                 $text = $this->getSubpageText();
 775                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 776                 return( $text );
 777         }
 778
 779         /**
 780          * Get a URL-encoded title (not an actual URL) including interwiki
 781          *
 782          * @return String the URL-encoded form
 783          */
 784         public function getPrefixedURL() {
 785                 $s = $this->prefix( $this->mDbkeyform );
 786                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 787                 return $s;
 788         }
 789
 790         /**
 791          * Get a real URL referring to this title, with interwiki link and
 792          * fragment
 793          *
 794          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 795          *   links. Can be specified as an associative array as well, e.g.,
 796          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 797          * @param $variant String language variant of url (for sr, zh..)
 798          * @return String the URL
 799          */
 800         public function getFullURL( $query = '', $variant = false ) {
 801                 global $wgServer, $wgRequest;
 802
 803                 if ( is_array( $query ) ) {
 804                         $query = wfArrayToCGI( $query );
 805                 }
 806
 807                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 808                 if ( !$interwiki ) {
 809                         $url = $this->getLocalURL( $query, $variant );
 810
 811                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 812                         // Correct fix would be to move the prepending elsewhere.
 813                         if ( $wgRequest->getVal( 'action' ) != 'render' ) {
 814                                 $url = $wgServer . $url;
 815                         }
 816                 } else {
 817                         $baseUrl = $interwiki->getURL();
 818
 819                         $namespace = wfUrlencode( $this->getNsText() );
 820                         if ( $namespace != '' ) {
 821                                 # Can this actually happen? Interwikis shouldn't be parsed.
 822                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 823                                 $namespace .= ':';
 824                         }
 825                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 826                         $url = wfAppendQuery( $url, $query );
 827                 }
 828
 829                 # Finally, add the fragment.
 830                 $url .= $this->getFragmentForURL();
 831
 832                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 833                 return $url;
 834         }
 835
 836         /**
 837          * Get a URL with no fragment or server name.  If this page is generated
 838          * with action=render, $wgServer is prepended.
 839          *
 840          * @param $query Mixed: an optional query string; if not specified,
 841          *   $wgArticlePath will be used.  Can be specified as an associative array
 842          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 843          *   URL-escaped).
 844          * @param $variant String language variant of url (for sr, zh..)
 845          * @return String the URL
 846          */
 847         public function getLocalURL( $query = '', $variant = false ) {
 848                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 849                 global $wgVariantArticlePath, $wgContLang;
 850
 851                 if ( is_array( $query ) ) {
 852                         $query = wfArrayToCGI( $query );
 853                 }
 854
 855                 if ( $this->isExternal() ) {
 856                         $url = $this->getFullURL();
 857                         if ( $query ) {
 858                                 // This is currently only used for edit section links in the
 859                                 // context of interwiki transclusion. In theory we should
 860                                 // append the query to the end of any existing query string,
 861                                 // but interwiki transclusion is already broken in that case.
 862                                 $url .= "?$query";
 863                         }
 864                 } else {
 865                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 866                         if ( $query == '' ) {
 867                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 868                                         if ( !$wgVariantArticlePath ) {
 869                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 870                                         } else {
 871                                                 $variantArticlePath = $wgVariantArticlePath;
 872                                         }
 873                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 874                                         $url = str_replace( '$1', $dbkey, $url  );
 875                                 } else {
 876                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 877                                 }
 878                         } else {
 879                                 global $wgActionPaths;
 880                                 $url = false;
 881                                 $matches = array();
 882                                 if ( !empty( $wgActionPaths ) &&
 883                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 884                                 {
 885                                         $action = urldecode( $matches[2] );
 886                                         if ( isset( $wgActionPaths[$action] ) ) {
 887                                                 $query = $matches[1];
 888                                                 if ( isset( $matches[4] ) ) {
 889                                                         $query .= $matches[4];
 890                                                 }
 891                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 892                                                 if ( $query != '' ) {
 893                                                         $url = wfAppendQuery( $url, $query );
 894                                                 }
 895                                         }
 896                                 }
 897                                 if ( $url === false ) {
 898                                         if ( $query == '-' ) {
 899                                                 $query = '';
 900                                         }
 901                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 902                                 }
 903                         }
 904
 905                         // FIXME: this causes breakage in various places when we
 906                         // actually expected a local URL and end up with dupe prefixes.
 907                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 908                                 $url = $wgServer . $url;
 909                         }
 910                 }
 911                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 912                 return $url;
 913         }
 914
 915         /**
 916          * Get a URL that's the simplest URL that will be valid to link, locally,
 917          * to the current Title.  It includes the fragment, but does not include
 918          * the server unless action=render is used (or the link is external).  If
 919          * there's a fragment but the prefixed text is empty, we just return a link
 920          * to the fragment.
 921          *
 922          * The result obviously should not be URL-escaped, but does need to be
 923          * HTML-escaped if it's being output in HTML.
 924          *
 925          * @param $query Array of Strings An associative array of key => value pairs for the
 926          *   query string.  Keys and values will be escaped.
 927          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 928          *   for external links.  Default is "false" (same variant as current page,
 929          *   for anonymous users).
 930          * @return String the URL
 931          */
 932         public function getLinkUrl( $query = array(), $variant = false ) {
 933                 wfProfileIn( __METHOD__ );
 934                 if ( $this->isExternal() ) {
 935                         $ret = $this->getFullURL( $query );
 936                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 937                         $ret = $this->getFragmentForURL();
 938                 } else {
 939                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 940                 }
 941                 wfProfileOut( __METHOD__ );
 942                 return $ret;
 943         }
 944
 945         /**
 946          * Get an HTML-escaped version of the URL form, suitable for
 947          * using in a link, without a server name or fragment
 948          *
 949          * @param $query String an optional query string
 950          * @return String the URL
 951          */
 952         public function escapeLocalURL( $query = '' ) {
 953                 return htmlspecialchars( $this->getLocalURL( $query ) );
 954         }
 955
 956         /**
 957          * Get an HTML-escaped version of the URL form, suitable for
 958          * using in a link, including the server name and fragment
 959          *
 960          * @param $query String an optional query string
 961          * @return String the URL
 962          */
 963         public function escapeFullURL( $query = '' ) {
 964                 return htmlspecialchars( $this->getFullURL( $query ) );
 965         }
 966
 967         /**
 968          * Get the URL form for an internal link.
 969          * - Used in various Squid-related code, in case we have a different
 970          * internal hostname for the server from the exposed one.
 971          *
 972          * @param $query String an optional query string
 973          * @param $variant String language variant of url (for sr, zh..)
 974          * @return String the URL
 975          */
 976         public function getInternalURL( $query = '', $variant = false ) {
 977                 global $wgInternalServer, $wgServer;
 978                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
 979                 $url = $server . $this->getLocalURL( $query, $variant );
 980                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
 981                 return $url;
 982         }
 983
 984         /**
 985          * Get the edit URL for this Title
 986          *
 987          * @return String the URL, or a null string if this is an
 988          *  interwiki link
 989          */
 990         public function getEditURL() {
 991                 if ( $this->mInterwiki != '' ) {
 992                         return '';
 993                 }
 994                 $s = $this->getLocalURL( 'action=edit' );
 995
 996                 return $s;
 997         }
 998
 999         /**
1000          * Get the HTML-escaped displayable text form.
1001          * Used for the title field in <a> tags.
1002          *
1003          * @return String the text, including any prefixes
1004          */
1005         public function getEscapedText() {
1006                 return htmlspecialchars( $this->getPrefixedText() );
1007         }
1008
1009         /**
1010          * Is this Title interwiki?
1011          *
1012          * @return Bool
1013          */
1014         public function isExternal() {
1015                 return ( $this->mInterwiki != '' );
1016         }
1017
1018         /**
1019          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1020          *
1021          * @param $action String Action to check (default: edit)
1022          * @return Bool
1023          */
1024         public function isSemiProtected( $action = 'edit' ) {
1025                 if ( $this->exists() ) {
1026                         $restrictions = $this->getRestrictions( $action );
1027                         if ( count( $restrictions ) > 0 ) {
1028                                 foreach ( $restrictions as $restriction ) {
1029                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1030                                                 return false;
1031                                         }
1032                                 }
1033                         } else {
1034                                 # Not protected
1035                                 return false;
1036                         }
1037                         return true;
1038                 } else {
1039                         # If it doesn't exist, it can't be protected
1040                         return false;
1041                 }
1042         }
1043
1044         /**
1045          * Does the title correspond to a protected article?
1046          *
1047          * @param $action String the action the page is protected from,
1048          * by default checks all actions.
1049          * @return Bool
1050          */
1051         public function isProtected( $action = '' ) {
1052                 global $wgRestrictionLevels;
1053
1054                 $restrictionTypes = $this->getRestrictionTypes();
1055
1056                 # Special pages have inherent protection
1057                 if( $this->getNamespace() == NS_SPECIAL ) {
1058                         return true;
1059                 }
1060
1061                 # Check regular protection levels
1062                 foreach ( $restrictionTypes as $type ) {
1063                         if ( $action == $type || $action == '' ) {
1064                                 $r = $this->getRestrictions( $type );
1065                                 foreach ( $wgRestrictionLevels as $level ) {
1066                                         if ( in_array( $level, $r ) && $level != '' ) {
1067                                                 return true;
1068                                         }
1069                                 }
1070                         }
1071                 }
1072
1073                 return false;
1074         }
1075
1076         /**
1077          * Is this a conversion table for the LanguageConverter?
1078          *
1079          * @return Bool
1080          */
1081         public function isConversionTable() {
1082                 if(
1083                         $this->getNamespace() == NS_MEDIAWIKI &&
1084                         strpos( $this->getText(), 'Conversiontable' ) !== false
1085                 )
1086                 {
1087                         return true;
1088                 }
1089
1090                 return false;
1091         }
1092
1093         /**
1094          * Is $wgUser watching this page?
1095          *
1096          * @return Bool
1097          */
1098         public function userIsWatching() {
1099                 global $wgUser;
1100
1101                 if ( is_null( $this->mWatched ) ) {
1102                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1103                                 $this->mWatched = false;
1104                         } else {
1105                                 $this->mWatched = $wgUser->isWatched( $this );
1106                         }
1107                 }
1108                 return $this->mWatched;
1109         }
1110
1111         /**
1112          * Can $wgUser perform $action on this page?
1113          * This skips potentially expensive cascading permission checks
1114          * as well as avoids expensive error formatting
1115          *
1116          * Suitable for use for nonessential UI controls in common cases, but
1117          * _not_ for functional access control.
1118          *
1119          * May provide false positives, but should never provide a false negative.
1120          *
1121          * @param $action String action that permission needs to be checked for
1122          * @return Bool
1123          */
1124         public function quickUserCan( $action ) {
1125                 return $this->userCan( $action, false );
1126         }
1127
1128         /**
1129          * Determines if $user is unable to edit this page because it has been protected
1130          * by $wgNamespaceProtection.
1131          *
1132          * @param $user User object, $wgUser will be used if not passed
1133          * @return Bool
1134          */
1135         public function isNamespaceProtected( User $user = null ) {
1136                 global $wgNamespaceProtection;
1137
1138                 if ( $user === null ) {
1139                         global $wgUser;
1140                         $user = $wgUser;
1141                 }
1142
1143                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1144                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1145                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1146                                         return true;
1147                                 }
1148                         }
1149                 }
1150                 return false;
1151         }
1152
1153         /**
1154          * Can $wgUser perform $action on this page?
1155          *
1156          * @param $action String action that permission needs to be checked for
1157          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1158          * @return Bool
1159          */
1160         public function userCan( $action, $doExpensiveQueries = true ) {
1161                 global $wgUser;
1162                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1163         }
1164
1165         /**
1166          * Can $user perform $action on this page?
1167          *
1168          * FIXME: This *does not* check throttles (User::pingLimiter()).
1169          *
1170          * @param $action String action that permission needs to be checked for
1171          * @param $user User to check
1172          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries by
1173          *   skipping checks for cascading protections and user blocks.
1174          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1175          * @return Array of arguments to wfMsg to explain permissions problems.
1176          */
1177         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1178                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1179
1180                 // Remove the errors being ignored.
1181                 foreach ( $errors as $index => $error ) {
1182                         $error_key = is_array( $error ) ? $error[0] : $error;
1183
1184                         if ( in_array( $error_key, $ignoreErrors ) ) {
1185                                 unset( $errors[$index] );
1186                         }
1187                 }
1188
1189                 return $errors;
1190         }
1191
1192         /**
1193          * Permissions checks that fail most often, and which are easiest to test.
1194          *
1195          * @param $action String the action to check
1196          * @param $user User user to check
1197          * @param $errors Array list of current errors
1198          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1199          * @param $short Boolean short circuit on first error
1200          *
1201          * @return Array list of errors
1202          */
1203         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1204                 if ( $action == 'create' ) {
1205                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1206                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1207                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1208                         }
1209                 } elseif ( $action == 'move' ) {
1210                         if ( !$user->isAllowed( 'move-rootuserpages' )
1211                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1212                                 // Show user page-specific message only if the user can move other pages
1213                                 $errors[] = array( 'cant-move-user-page' );
1214                         }
1215
1216                         // Check if user is allowed to move files if it's a file
1217                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1218                                 $errors[] = array( 'movenotallowedfile' );
1219                         }
1220
1221                         if ( !$user->isAllowed( 'move' ) ) {
1222                                 // User can't move anything
1223                                 global $wgGroupPermissions;
1224                                 $userCanMove = false;
1225                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1226                                         $userCanMove = $wgGroupPermissions['user']['move'];
1227                                 }
1228                                 $autoconfirmedCanMove = false;
1229                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1230                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1231                                 }
1232                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1233                                         // custom message if logged-in users without any special rights can move
1234                                         $errors[] = array( 'movenologintext' );
1235                                 } else {
1236                                         $errors[] = array( 'movenotallowed' );
1237                                 }
1238                         }
1239                 } elseif ( $action == 'move-target' ) {
1240                         if ( !$user->isAllowed( 'move' ) ) {
1241                                 // User can't move anything
1242                                 $errors[] = array( 'movenotallowed' );
1243                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1244                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1245                                 // Show user page-specific message only if the user can move other pages
1246                                 $errors[] = array( 'cant-move-to-user-page' );
1247                         }
1248                 } elseif ( !$user->isAllowed( $action ) ) {
1249                         // We avoid expensive display logic for quickUserCan's and such
1250                         $groups = false;
1251                         if ( !$short ) {
1252                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1253                                         User::getGroupsWithPermission( $action ) );
1254                         }
1255
1256                         if ( $groups ) {
1257                                 global $wgLang;
1258                                 $return = array(
1259                                         'badaccess-groups',
1260                                         $wgLang->commaList( $groups ),
1261                                         count( $groups )
1262                                 );
1263                         } else {
1264                                 $return = array( 'badaccess-group0' );
1265                         }
1266                         $errors[] = $return;
1267                 }
1268
1269                 return $errors;
1270         }
1271
1272         /**
1273          * Add the resulting error code to the errors array
1274          *
1275          * @param $errors Array list of current errors
1276          * @param $result Mixed result of errors
1277          *
1278          * @return Array list of errors
1279          */
1280         private function resultToError( $errors, $result ) {
1281                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1282                         // A single array representing an error
1283                         $errors[] = $result;
1284                 } else if ( is_array( $result ) && is_array( $result[0] ) ) {
1285                         // A nested array representing multiple errors
1286                         $errors = array_merge( $errors, $result );
1287                 } else if ( $result !== '' && is_string( $result ) ) {
1288                         // A string representing a message-id
1289                         $errors[] = array( $result );
1290                 } else if ( $result === false ) {
1291                         // a generic "We don't want them to do that"
1292                         $errors[] = array( 'badaccess-group0' );
1293                 }
1294                 return $errors;
1295         }
1296
1297         /**
1298          * Check various permission hooks
1299          *
1300          * @param $action String the action to check
1301          * @param $user User user to check
1302          * @param $errors Array list of current errors
1303          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1304          * @param $short Boolean short circuit on first error
1305          *
1306          * @return Array list of errors
1307          */
1308         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1309                 // Use getUserPermissionsErrors instead
1310                 $result = '';
1311                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1312                         return $result ? array() : array( array( 'badaccess-group0' ) );
1313                 }
1314                 // Check getUserPermissionsErrors hook
1315                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1316                         $errors = $this->resultToError( $errors, $result );
1317                 }
1318                 // Check getUserPermissionsErrorsExpensive hook
1319                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1320                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1321                         $errors = $this->resultToError( $errors, $result );
1322                 }
1323
1324                 return $errors;
1325         }
1326
1327         /**
1328          * Check permissions on special pages & namespaces
1329          *
1330          * @param $action String the action to check
1331          * @param $user User user to check
1332          * @param $errors Array list of current errors
1333          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1334          * @param $short Boolean short circuit on first error
1335          *
1336          * @return Array list of errors
1337          */
1338         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1339                 # Only 'createaccount' and 'execute' can be performed on
1340                 # special pages, which don't actually exist in the DB.
1341                 $specialOKActions = array( 'createaccount', 'execute' );
1342                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1343                         $errors[] = array( 'ns-specialprotected' );
1344                 }
1345
1346                 # Check $wgNamespaceProtection for restricted namespaces
1347                 if ( $this->isNamespaceProtected( $user ) ) {
1348                         $ns = $this->mNamespace == NS_MAIN ?
1349                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1350                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1351                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1352                 }
1353
1354                 return $errors;
1355         }
1356
1357         /**
1358          * Check CSS/JS sub-page permissions
1359          *
1360          * @param $action String the action to check
1361          * @param $user User user to check
1362          * @param $errors Array list of current errors
1363          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1364          * @param $short Boolean short circuit on first error
1365          *
1366          * @return Array list of errors
1367          */
1368         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1369                 # Protect css/js subpages of user pages
1370                 # XXX: this might be better using restrictions
1371                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssSubpage()
1372                 #      and $this->userCanEditJsSubpage() from working
1373                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1374                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1375                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1376                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1377                                 $errors[] = array( 'customcssjsprotected' );
1378                         } else if ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1379                                 $errors[] = array( 'customcssjsprotected' );
1380                         }
1381                 }
1382
1383                 return $errors;
1384         }
1385
1386         /**
1387          * Check against page_restrictions table requirements on this
1388          * page. The user must possess all required rights for this
1389          * action.
1390          *
1391          * @param $action String the action to check
1392          * @param $user User user to check
1393          * @param $errors Array list of current errors
1394          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1395          * @param $short Boolean short circuit on first error
1396          *
1397          * @return Array list of errors
1398          */
1399         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1400                 foreach ( $this->getRestrictions( $action ) as $right ) {
1401                         // Backwards compatibility, rewrite sysop -> protect
1402                         if ( $right == 'sysop' ) {
1403                                 $right = 'protect';
1404                         }
1405                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1406                                 // Users with 'editprotected' permission can edit protected pages
1407                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected' ) ) {
1408                                         // Users with 'editprotected' permission cannot edit protected pages
1409                                         // with cascading option turned on.
1410                                         if ( $this->mCascadeRestriction ) {
1411                                                 $errors[] = array( 'protectedpagetext', $right );
1412                                         }
1413                                 } else {
1414                                         $errors[] = array( 'protectedpagetext', $right );
1415                                 }
1416                         }
1417                 }
1418
1419                 return $errors;
1420         }
1421
1422         /**
1423          * Check restrictions on cascading pages.
1424          *
1425          * @param $action String the action to check
1426          * @param $user User to check
1427          * @param $errors Array list of current errors
1428          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1429          * @param $short Boolean short circuit on first error
1430          *
1431          * @return Array list of errors
1432          */
1433         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1434                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1435                         # We /could/ use the protection level on the source page, but it's
1436                         # fairly ugly as we have to establish a precedence hierarchy for pages
1437                         # included by multiple cascade-protected pages. So just restrict
1438                         # it to people with 'protect' permission, as they could remove the
1439                         # protection anyway.
1440                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1441                         # Cascading protection depends on more than this page...
1442                         # Several cascading protected pages may include this page...
1443                         # Check each cascading level
1444                         # This is only for protection restrictions, not for all actions
1445                         if ( isset( $restrictions[$action] ) ) {
1446                                 foreach ( $restrictions[$action] as $right ) {
1447                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1448                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1449                                                 $pages = '';
1450                                                 foreach ( $cascadingSources as $page )
1451                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1452                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1453                                         }
1454                                 }
1455                         }
1456                 }
1457
1458                 return $errors;
1459         }
1460
1461         /**
1462          * Check action permissions not already checked in checkQuickPermissions
1463          *
1464          * @param $action String the action to check
1465          * @param $user User to check
1466          * @param $errors Array list of current errors
1467          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1468          * @param $short Boolean short circuit on first error
1469          *
1470          * @return Array list of errors
1471          */
1472         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1473                 if ( $action == 'protect' ) {
1474                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1475                                 // If they can't edit, they shouldn't protect.
1476                                 $errors[] = array( 'protect-cantedit' );
1477                         }
1478                 } elseif ( $action == 'create' ) {
1479                         $title_protection = $this->getTitleProtection();
1480                         if( $title_protection ) {
1481                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1482                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1483                                 }
1484                                 if( $title_protection['pt_create_perm'] == '' || !$user->isAllowed( $title_protection['pt_create_perm'] ) ) {
1485                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1486                                 }
1487                         }
1488                 } elseif ( $action == 'move' ) {
1489                         // Check for immobile pages
1490                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1491                                 // Specific message for this case
1492                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1493                         } elseif ( !$this->isMovable() ) {
1494                                 // Less specific message for rarer cases
1495                                 $errors[] = array( 'immobile-page' );
1496                         }
1497                 } elseif ( $action == 'move-target' ) {
1498                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1499                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1500                         } elseif ( !$this->isMovable() ) {
1501                                 $errors[] = array( 'immobile-target-page' );
1502                         }
1503                 }
1504                 return $errors;
1505         }
1506
1507         /**
1508          * Check that the user isn't blocked from editting.
1509          *
1510          * @param $action String the action to check
1511          * @param $user User to check
1512          * @param $errors Array list of current errors
1513          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1514          * @param $short Boolean short circuit on first error
1515          *
1516          * @return Array list of errors
1517          */
1518         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1519                 if( !$doExpensiveQueries ) {
1520                         return $errors;
1521                 }
1522
1523                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1524
1525                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1526                         $errors[] = array( 'confirmedittext' );
1527                 }
1528
1529                 if ( in_array( $action, array( 'read', 'createaccount', 'unblock' ) ) ){
1530                         // Edit blocks should not affect reading.
1531                         // Account creation blocks handled at userlogin.
1532                         // Unblocking handled in SpecialUnblock
1533                 } elseif( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ){
1534                         // Don't block the user from editing their own talk page unless they've been
1535                         // explicitly blocked from that too.
1536                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1537                         $block = $user->mBlock;
1538
1539                         // This is from OutputPage::blockedPage
1540                         // Copied at r23888 by werdna
1541
1542                         $id = $user->blockedBy();
1543                         $reason = $user->blockedFor();
1544                         if ( $reason == '' ) {
1545                                 $reason = wfMsg( 'blockednoreason' );
1546                         }
1547                         $ip = wfGetIP();
1548
1549                         if ( is_numeric( $id ) ) {
1550                                 $name = User::whoIs( $id );
1551                         } else {
1552                                 $name = $id;
1553                         }
1554
1555                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1556                         $blockid = $block->getId();
1557                         $blockExpiry = $user->mBlock->mExpiry;
1558                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1559                         if ( $blockExpiry == 'infinity' ) {
1560                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1561                         } else {
1562                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1563                         }
1564
1565                         $intended = strval( $user->mBlock->getTarget() );
1566
1567                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1568                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1569                 }
1570
1571                 return $errors;
1572         }
1573
1574         /**
1575          * Can $user perform $action on this page? This is an internal function,
1576          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1577          * checks on wfReadOnly() and blocks)
1578          *
1579          * @param $action String action that permission needs to be checked for
1580          * @param $user User to check
1581          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1582          * @param $short Bool Set this to true to stop after the first permission error.
1583          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1584          */
1585         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1586                 wfProfileIn( __METHOD__ );
1587
1588                 $errors = array();
1589                 $checks = array(
1590                         'checkQuickPermissions',
1591                         'checkPermissionHooks',
1592                         'checkSpecialsAndNSPermissions',
1593                         'checkCSSandJSPermissions',
1594                         'checkPageRestrictions',
1595                         'checkCascadingSourcesRestrictions',
1596                         'checkActionPermissions',
1597                         'checkUserBlock'
1598                 );
1599
1600                 while( count( $checks ) > 0 &&
1601                            !( $short && count( $errors ) > 0 ) ) {
1602                         $method = array_shift( $checks );
1603                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1604                 }
1605
1606                 wfProfileOut( __METHOD__ );
1607                 return $errors;
1608         }
1609
1610         /**
1611          * Is this title subject to title protection?
1612          * Title protection is the one applied against creation of such title.
1613          *
1614          * @return Mixed An associative array representing any existent title
1615          *   protection, or false if there's none.
1616          */
1617         private function getTitleProtection() {
1618                 // Can't protect pages in special namespaces
1619                 if ( $this->getNamespace() < 0 ) {
1620                         return false;
1621                 }
1622
1623                 // Can't protect pages that exist.
1624                 if ( $this->exists() ) {
1625                         return false;
1626                 }
1627
1628                 if ( !isset( $this->mTitleProtection ) ) {
1629                         $dbr = wfGetDB( DB_SLAVE );
1630                         $res = $dbr->select( 'protected_titles', '*',
1631                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1632                                 __METHOD__ );
1633
1634                         // fetchRow returns false if there are no rows.
1635                         $this->mTitleProtection = $dbr->fetchRow( $res );
1636                 }
1637                 return $this->mTitleProtection;
1638         }
1639
1640         /**
1641          * Update the title protection status
1642          *
1643          * @param $create_perm String Permission required for creation
1644          * @param $reason String Reason for protection
1645          * @param $expiry String Expiry timestamp
1646          * @return boolean true
1647          */
1648         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1649                 global $wgUser, $wgContLang;
1650
1651                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1652                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1653                         // No change
1654                         return true;
1655                 }
1656
1657                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1658
1659                 $dbw = wfGetDB( DB_MASTER );
1660
1661                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
1662
1663                 $expiry_description = '';
1664                 if ( $encodedExpiry != $dbw->getInfinity() ) {
1665                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1666                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1667                 } else {
1668                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1669                 }
1670
1671                 # Update protection table
1672                 if ( $create_perm != '' ) {
1673                         $this->mTitleProtection = array(
1674                                         'pt_namespace' => $namespace,
1675                                         'pt_title' => $title,
1676                                         'pt_create_perm' => $create_perm,
1677                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
1678                                         'pt_expiry' => $encodedExpiry,
1679                                         'pt_user' => $wgUser->getId(),
1680                                         'pt_reason' => $reason,
1681                                 );
1682                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1683                                 $this->mTitleProtection, __METHOD__     );
1684                 } else {
1685                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1686                                 'pt_title' => $title ), __METHOD__ );
1687                         $this->mTitleProtection = false;
1688                 }
1689
1690                 # Update the protection log
1691                 if ( $dbw->affectedRows() ) {
1692                         $log = new LogPage( 'protect' );
1693
1694                         if ( $create_perm ) {
1695                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1696                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1697                         } else {
1698                                 $log->addEntry( 'unprotect', $this, $reason );
1699                         }
1700                 }
1701
1702                 return true;
1703         }
1704
1705         /**
1706          * Remove any title protection due to page existing
1707          */
1708         public function deleteTitleProtection() {
1709                 $dbw = wfGetDB( DB_MASTER );
1710
1711                 $dbw->delete(
1712                         'protected_titles',
1713                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1714                         __METHOD__
1715                 );
1716                 $this->mTitleProtection = false;
1717         }
1718
1719         /**
1720          * Would anybody with sufficient privileges be able to move this page?
1721          * Some pages just aren't movable.
1722          *
1723          * @return Bool TRUE or FALSE
1724          */
1725         public function isMovable() {
1726                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1727         }
1728
1729         /**
1730          * Can $wgUser read this page?
1731          *
1732          * @return Bool
1733          * @todo fold these checks into userCan()
1734          */
1735         public function userCanRead() {
1736                 global $wgUser, $wgGroupPermissions;
1737
1738                 static $useShortcut = null;
1739
1740                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1741                 if ( is_null( $useShortcut ) ) {
1742                         global $wgRevokePermissions;
1743                         $useShortcut = true;
1744                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1745                                 # Not a public wiki, so no shortcut
1746                                 $useShortcut = false;
1747                         } elseif ( !empty( $wgRevokePermissions ) ) {
1748                                 /*
1749                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1750                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1751                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1752                                  * reading is allowed.
1753                                  */
1754                                 foreach ( $wgRevokePermissions as $perms ) {
1755                                         if ( !empty( $perms['read'] ) ) {
1756                                                 # We might be removing the read right from the user, so no shortcut
1757                                                 $useShortcut = false;
1758                                                 break;
1759                                         }
1760                                 }
1761                         }
1762                 }
1763
1764                 $result = null;
1765                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1766                 if ( $result !== null ) {
1767                         return $result;
1768                 }
1769
1770                 # Shortcut for public wikis, allows skipping quite a bit of code
1771                 if ( $useShortcut ) {
1772                         return true;
1773                 }
1774
1775                 if ( $wgUser->isAllowed( 'read' ) ) {
1776                         return true;
1777                 } else {
1778                         global $wgWhitelistRead;
1779
1780                         # Always grant access to the login page.
1781                         # Even anons need to be able to log in.
1782                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'ChangePassword' ) ) {
1783                                 return true;
1784                         }
1785
1786                         # Bail out if there isn't whitelist
1787                         if ( !is_array( $wgWhitelistRead ) ) {
1788                                 return false;
1789                         }
1790
1791                         # Check for explicit whitelisting
1792                         $name = $this->getPrefixedText();
1793                         $dbName = $this->getPrefixedDBKey();
1794                         // Check with and without underscores
1795                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1796                                 return true;
1797
1798                         # Old settings might have the title prefixed with
1799                         # a colon for main-namespace pages
1800                         if ( $this->getNamespace() == NS_MAIN ) {
1801                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1802                                         return true;
1803                                 }
1804                         }
1805
1806                         # If it's a special page, ditch the subpage bit and check again
1807                         if ( $this->getNamespace() == NS_SPECIAL ) {
1808                                 $name = $this->getDBkey();
1809                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
1810                                 if ( $name === false ) {
1811                                         # Invalid special page, but we show standard login required message
1812                                         return false;
1813                                 }
1814
1815                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1816                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1817                                         return true;
1818                                 }
1819                         }
1820
1821                 }
1822                 return false;
1823         }
1824
1825         /**
1826          * Is this the mainpage?
1827          * @note Title::newFromText seams to be sufficiently optimized by the title
1828          * cache that we don't need to over-optimize by doing direct comparisons and
1829          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1830          * ends up reporting something differently than $title->isMainPage();
1831          *
1832          * @return Bool
1833          */
1834         public function isMainPage() {
1835                 return $this->equals( Title::newMainPage() );
1836         }
1837
1838         /**
1839          * Is this a talk page of some sort?
1840          *
1841          * @return Bool
1842          */
1843         public function isTalkPage() {
1844                 return MWNamespace::isTalk( $this->getNamespace() );
1845         }
1846
1847         /**
1848          * Is this a subpage?
1849          *
1850          * @return Bool
1851          */
1852         public function isSubpage() {
1853                 return MWNamespace::hasSubpages( $this->mNamespace )
1854                         ? strpos( $this->getText(), '/' ) !== false
1855                         : false;
1856         }
1857
1858         /**
1859          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1860          *
1861          * @return Bool
1862          */
1863         public function hasSubpages() {
1864                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1865                         # Duh
1866                         return false;
1867                 }
1868
1869                 # We dynamically add a member variable for the purpose of this method
1870                 # alone to cache the result.  There's no point in having it hanging
1871                 # around uninitialized in every Title object; therefore we only add it
1872                 # if needed and don't declare it statically.
1873                 if ( isset( $this->mHasSubpages ) ) {
1874                         return $this->mHasSubpages;
1875                 }
1876
1877                 $subpages = $this->getSubpages( 1 );
1878                 if ( $subpages instanceof TitleArray ) {
1879                         return $this->mHasSubpages = (bool)$subpages->count();
1880                 }
1881                 return $this->mHasSubpages = false;
1882         }
1883
1884         /**
1885          * Get all subpages of this page.
1886          *
1887          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
1888          * @return mixed TitleArray, or empty array if this page's namespace
1889          *  doesn't allow subpages
1890          */
1891         public function getSubpages( $limit = -1 ) {
1892                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1893                         return array();
1894                 }
1895
1896                 $dbr = wfGetDB( DB_SLAVE );
1897                 $conds['page_namespace'] = $this->getNamespace();
1898                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1899                 $options = array();
1900                 if ( $limit > -1 ) {
1901                         $options['LIMIT'] = $limit;
1902                 }
1903                 return $this->mSubpages = TitleArray::newFromResult(
1904                         $dbr->select( 'page',
1905                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1906                                 $conds,
1907                                 __METHOD__,
1908                                 $options
1909                         )
1910                 );
1911         }
1912
1913         /**
1914          * Could this page contain custom CSS or JavaScript, based
1915          * on the title?
1916          *
1917          * @return Bool
1918          */
1919         public function isCssOrJsPage() {
1920                 return $this->mNamespace == NS_MEDIAWIKI
1921                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1922         }
1923
1924         /**
1925          * Is this a .css or .js subpage of a user page?
1926          * @return Bool
1927          */
1928         public function isCssJsSubpage() {
1929                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1930         }
1931
1932         /**
1933          * Is this a *valid* .css or .js subpage of a user page?
1934          *
1935          * @return Bool
1936          * @deprecated since 1.17
1937          */
1938         public function isValidCssJsSubpage() {
1939                 return $this->isCssJsSubpage();
1940         }
1941
1942         /**
1943          * Trim down a .css or .js subpage title to get the corresponding skin name
1944          *
1945          * @return string containing skin name from .css or .js subpage title
1946          */
1947         public function getSkinFromCssJsSubpage() {
1948                 $subpage = explode( '/', $this->mTextform );
1949                 $subpage = $subpage[ count( $subpage ) - 1 ];
1950                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1951         }
1952
1953         /**
1954          * Is this a .css subpage of a user page?
1955          *
1956          * @return Bool
1957          */
1958         public function isCssSubpage() {
1959                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1960         }
1961
1962         /**
1963          * Is this a .js subpage of a user page?
1964          *
1965          * @return Bool
1966          */
1967         public function isJsSubpage() {
1968                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1969         }
1970
1971         /**
1972          * Protect css subpages of user pages: can $wgUser edit
1973          * this page?
1974          *
1975          * @return Bool
1976          * @todo XXX: this might be better using restrictions
1977          */
1978         public function userCanEditCssSubpage() {
1979                 global $wgUser;
1980                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
1981                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1982         }
1983
1984         /**
1985          * Protect js subpages of user pages: can $wgUser edit
1986          * this page?
1987          *
1988          * @return Bool
1989          * @todo XXX: this might be better using restrictions
1990          */
1991         public function userCanEditJsSubpage() {
1992                 global $wgUser;
1993                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
1994                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1995         }
1996
1997         /**
1998          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
1999          *
2000          * @return Bool If the page is subject to cascading restrictions.
2001          */
2002         public function isCascadeProtected() {
2003                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2004                 return ( $sources > 0 );
2005         }
2006
2007         /**
2008          * Cascading protection: Get the source of any cascading restrictions on this page.
2009          *
2010          * @param $getPages Bool Whether or not to retrieve the actual pages
2011          *        that the restrictions have come from.
2012          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2013          *     have come, false for none, or true if such restrictions exist, but $getPages
2014          *     was not set.  The restriction array is an array of each type, each of which
2015          *     contains a array of unique groups.
2016          */
2017         public function getCascadeProtectionSources( $getPages = true ) {
2018                 global $wgContLang;
2019                 $pagerestrictions = array();
2020
2021                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2022                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2023                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2024                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2025                 }
2026
2027                 wfProfileIn( __METHOD__ );
2028
2029                 $dbr = wfGetDB( DB_SLAVE );
2030
2031                 if ( $this->getNamespace() == NS_FILE ) {
2032                         $tables = array( 'imagelinks', 'page_restrictions' );
2033                         $where_clauses = array(
2034                                 'il_to' => $this->getDBkey(),
2035                                 'il_from=pr_page',
2036                                 'pr_cascade' => 1
2037                         );
2038                 } else {
2039                         $tables = array( 'templatelinks', 'page_restrictions' );
2040                         $where_clauses = array(
2041                                 'tl_namespace' => $this->getNamespace(),
2042                                 'tl_title' => $this->getDBkey(),
2043                                 'tl_from=pr_page',
2044                                 'pr_cascade' => 1
2045                         );
2046                 }
2047
2048                 if ( $getPages ) {
2049                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2050                                                    'pr_expiry', 'pr_type', 'pr_level' );
2051                         $where_clauses[] = 'page_id=pr_page';
2052                         $tables[] = 'page';
2053                 } else {
2054                         $cols = array( 'pr_expiry' );
2055                 }
2056
2057                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2058
2059                 $sources = $getPages ? array() : false;
2060                 $now = wfTimestampNow();
2061                 $purgeExpired = false;
2062
2063                 foreach ( $res as $row ) {
2064                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2065                         if ( $expiry > $now ) {
2066                                 if ( $getPages ) {
2067                                         $page_id = $row->pr_page;
2068                                         $page_ns = $row->page_namespace;
2069                                         $page_title = $row->page_title;
2070                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2071                                         # Add groups needed for each restriction type if its not already there
2072                                         # Make sure this restriction type still exists
2073
2074                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2075                                                 $pagerestrictions[$row->pr_type] = array();
2076                                         }
2077
2078                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2079                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2080                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2081                                         }
2082                                 } else {
2083                                         $sources = true;
2084                                 }
2085                         } else {
2086                                 // Trigger lazy purge of expired restrictions from the db
2087                                 $purgeExpired = true;
2088                         }
2089                 }
2090                 if ( $purgeExpired ) {
2091                         Title::purgeExpiredRestrictions();
2092                 }
2093
2094                 if ( $getPages ) {
2095                         $this->mCascadeSources = $sources;
2096                         $this->mCascadingRestrictions = $pagerestrictions;
2097                 } else {
2098                         $this->mHasCascadingRestrictions = $sources;
2099                 }
2100
2101                 wfProfileOut( __METHOD__ );
2102                 return array( $sources, $pagerestrictions );
2103         }
2104
2105         /**
2106          * Returns cascading restrictions for the current article
2107          *
2108          * @return Boolean
2109          */
2110         function areRestrictionsCascading() {
2111                 if ( !$this->mRestrictionsLoaded ) {
2112                         $this->loadRestrictions();
2113                 }
2114
2115                 return $this->mCascadeRestriction;
2116         }
2117
2118         /**
2119          * Loads a string into mRestrictions array
2120          *
2121          * @param $res Resource restrictions as an SQL result.
2122          * @param $oldFashionedRestrictions String comma-separated list of page
2123          *        restrictions from page table (pre 1.10)
2124          */
2125         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2126                 $rows = array();
2127
2128                 foreach ( $res as $row ) {
2129                         $rows[] = $row;
2130                 }
2131
2132                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2133         }
2134
2135         /**
2136          * Compiles list of active page restrictions from both page table (pre 1.10)
2137          * and page_restrictions table for this existing page.
2138          * Public for usage by LiquidThreads.
2139          *
2140          * @param $rows array of db result objects
2141          * @param $oldFashionedRestrictions string comma-separated list of page
2142          *        restrictions from page table (pre 1.10)
2143          */
2144         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2145                 global $wgContLang;
2146                 $dbr = wfGetDB( DB_SLAVE );
2147
2148                 $restrictionTypes = $this->getRestrictionTypes();
2149
2150                 foreach ( $restrictionTypes as $type ) {
2151                         $this->mRestrictions[$type] = array();
2152                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2153                 }
2154
2155                 $this->mCascadeRestriction = false;
2156
2157                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2158
2159                 if ( $oldFashionedRestrictions === null ) {
2160                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2161                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2162                 }
2163
2164                 if ( $oldFashionedRestrictions != '' ) {
2165
2166                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2167                                 $temp = explode( '=', trim( $restrict ) );
2168                                 if ( count( $temp ) == 1 ) {
2169                                         // old old format should be treated as edit/move restriction
2170                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2171                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2172                                 } else {
2173                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2174                                 }
2175                         }
2176
2177                         $this->mOldRestrictions = true;
2178
2179                 }
2180
2181                 if ( count( $rows ) ) {
2182                         # Current system - load second to make them override.
2183                         $now = wfTimestampNow();
2184                         $purgeExpired = false;
2185
2186                         # Cycle through all the restrictions.
2187                         foreach ( $rows as $row ) {
2188
2189                                 // Don't take care of restrictions types that aren't allowed
2190                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2191                                         continue;
2192
2193                                 // This code should be refactored, now that it's being used more generally,
2194                                 // But I don't really see any harm in leaving it in Block for now -werdna
2195                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2196
2197                                 // Only apply the restrictions if they haven't expired!
2198                                 if ( !$expiry || $expiry > $now ) {
2199                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2200                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2201
2202                                         $this->mCascadeRestriction |= $row->pr_cascade;
2203                                 } else {
2204                                         // Trigger a lazy purge of expired restrictions
2205                                         $purgeExpired = true;
2206                                 }
2207                         }
2208
2209                         if ( $purgeExpired ) {
2210                                 Title::purgeExpiredRestrictions();
2211                         }
2212                 }
2213
2214                 $this->mRestrictionsLoaded = true;
2215         }
2216
2217         /**
2218          * Load restrictions from the page_restrictions table
2219          *
2220          * @param $oldFashionedRestrictions String comma-separated list of page
2221          *        restrictions from page table (pre 1.10)
2222          */
2223         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2224                 global $wgContLang;
2225                 if ( !$this->mRestrictionsLoaded ) {
2226                         if ( $this->exists() ) {
2227                                 $dbr = wfGetDB( DB_SLAVE );
2228
2229                                 $res = $dbr->select(
2230                                         'page_restrictions',
2231                                         '*',
2232                                         array( 'pr_page' => $this->getArticleId() ),
2233                                         __METHOD__
2234                                 );
2235
2236                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2237                         } else {
2238                                 $title_protection = $this->getTitleProtection();
2239
2240                                 if ( $title_protection ) {
2241                                         $now = wfTimestampNow();
2242                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2243
2244                                         if ( !$expiry || $expiry > $now ) {
2245                                                 // Apply the restrictions
2246                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2247                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2248                                         } else { // Get rid of the old restrictions
2249                                                 Title::purgeExpiredRestrictions();
2250                                                 $this->mTitleProtection = false;
2251                                         }
2252                                 } else {
2253                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2254                                 }
2255                                 $this->mRestrictionsLoaded = true;
2256                         }
2257                 }
2258         }
2259
2260         /**
2261          * Purge expired restrictions from the page_restrictions table
2262          */
2263         static function purgeExpiredRestrictions() {
2264                 $dbw = wfGetDB( DB_MASTER );
2265                 $dbw->delete(
2266                         'page_restrictions',
2267                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2268                         __METHOD__
2269                 );
2270
2271                 $dbw->delete(
2272                         'protected_titles',
2273                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2274                         __METHOD__
2275                 );
2276         }
2277
2278         /**
2279          * Accessor/initialisation for mRestrictions
2280          *
2281          * @param $action String action that permission needs to be checked for
2282          * @return Array of Strings the array of groups allowed to edit this article
2283          */
2284         public function getRestrictions( $action ) {
2285                 if ( !$this->mRestrictionsLoaded ) {
2286                         $this->loadRestrictions();
2287                 }
2288                 return isset( $this->mRestrictions[$action] )
2289                                 ? $this->mRestrictions[$action]
2290                                 : array();
2291         }
2292
2293         /**
2294          * Get the expiry time for the restriction against a given action
2295          *
2296          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2297          *      or not protected at all, or false if the action is not recognised.
2298          */
2299         public function getRestrictionExpiry( $action ) {
2300                 if ( !$this->mRestrictionsLoaded ) {
2301                         $this->loadRestrictions();
2302                 }
2303                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2304         }
2305
2306         /**
2307          * Is there a version of this page in the deletion archive?
2308          *
2309          * @return Int the number of archived revisions
2310          */
2311         public function isDeleted() {
2312                 if ( $this->getNamespace() < 0 ) {
2313                         $n = 0;
2314                 } else {
2315                         $dbr = wfGetDB( DB_SLAVE );
2316                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2317                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2318                                 __METHOD__
2319                         );
2320                         if ( $this->getNamespace() == NS_FILE ) {
2321                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2322                                         array( 'fa_name' => $this->getDBkey() ),
2323                                         __METHOD__
2324                                 );
2325                         }
2326                 }
2327                 return (int)$n;
2328         }
2329
2330         /**
2331          * Is there a version of this page in the deletion archive?
2332          *
2333          * @return Boolean
2334          */
2335         public function isDeletedQuick() {
2336                 if ( $this->getNamespace() < 0 ) {
2337                         return false;
2338                 }
2339                 $dbr = wfGetDB( DB_SLAVE );
2340                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2341                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2342                         __METHOD__
2343                 );
2344                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2345                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2346                                 array( 'fa_name' => $this->getDBkey() ),
2347                                 __METHOD__
2348                         );
2349                 }
2350                 return $deleted;
2351         }
2352
2353         /**
2354          * Get the article ID for this Title from the link cache,
2355          * adding it if necessary
2356          *
2357          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2358          *  for update
2359          * @return Int the ID
2360          */
2361         public function getArticleID( $flags = 0 ) {
2362                 if ( $this->getNamespace() < 0 ) {
2363                         return $this->mArticleID = 0;
2364                 }
2365                 $linkCache = LinkCache::singleton();
2366                 if ( $flags & self::GAID_FOR_UPDATE ) {
2367                         $oldUpdate = $linkCache->forUpdate( true );
2368                         $linkCache->clearLink( $this );
2369                         $this->mArticleID = $linkCache->addLinkObj( $this );
2370                         $linkCache->forUpdate( $oldUpdate );
2371                 } else {
2372                         if ( -1 == $this->mArticleID ) {
2373                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2374                         }
2375                 }
2376                 return $this->mArticleID;
2377         }
2378
2379         /**
2380          * Is this an article that is a redirect page?
2381          * Uses link cache, adding it if necessary
2382          *
2383          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2384          * @return Bool
2385          */
2386         public function isRedirect( $flags = 0 ) {
2387                 if ( !is_null( $this->mRedirect ) ) {
2388                         return $this->mRedirect;
2389                 }
2390                 # Calling getArticleID() loads the field from cache as needed
2391                 if ( !$this->getArticleID( $flags ) ) {
2392                         return $this->mRedirect = false;
2393                 }
2394                 $linkCache = LinkCache::singleton();
2395                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2396
2397                 return $this->mRedirect;
2398         }
2399
2400         /**
2401          * What is the length of this page?
2402          * Uses link cache, adding it if necessary
2403          *
2404          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2405          * @return Int
2406          */
2407         public function getLength( $flags = 0 ) {
2408                 if ( $this->mLength != -1 ) {
2409                         return $this->mLength;
2410                 }
2411                 # Calling getArticleID() loads the field from cache as needed
2412                 if ( !$this->getArticleID( $flags ) ) {
2413                         return $this->mLength = 0;
2414                 }
2415                 $linkCache = LinkCache::singleton();
2416                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2417
2418                 return $this->mLength;
2419         }
2420
2421         /**
2422          * What is the page_latest field for this page?
2423          *
2424          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2425          * @return Int or 0 if the page doesn't exist
2426          */
2427         public function getLatestRevID( $flags = 0 ) {
2428                 if ( $this->mLatestID !== false ) {
2429                         return intval( $this->mLatestID );
2430                 }
2431                 # Calling getArticleID() loads the field from cache as needed
2432                 if ( !$this->getArticleID( $flags ) ) {
2433                         return $this->mLatestID = 0;
2434                 }
2435                 $linkCache = LinkCache::singleton();
2436                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2437
2438                 return $this->mLatestID;
2439         }
2440
2441         /**
2442          * This clears some fields in this object, and clears any associated
2443          * keys in the "bad links" section of the link cache.
2444          *
2445          * - This is called from Article::doEdit() and Article::insertOn() to allow
2446          * loading of the new page_id. It's also called from
2447          * Article::doDeleteArticle()
2448          *
2449          * @param $newid Int the new Article ID
2450          */
2451         public function resetArticleID( $newid ) {
2452                 $linkCache = LinkCache::singleton();
2453                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2454
2455                 if ( $newid === false ) {
2456                         $this->mArticleID = -1;
2457                 } else {
2458                         $this->mArticleID = intval( $newid );
2459                 }
2460                 $this->mRestrictionsLoaded = false;
2461                 $this->mRestrictions = array();
2462                 $this->mRedirect = null;
2463                 $this->mLength = -1;
2464                 $this->mLatestID = false;
2465         }
2466
2467         /**
2468          * Updates page_touched for this page; called from LinksUpdate.php
2469          *
2470          * @return Bool true if the update succeded
2471          */
2472         public function invalidateCache() {
2473                 if ( wfReadOnly() ) {
2474                         return;
2475                 }
2476                 $dbw = wfGetDB( DB_MASTER );
2477                 $success = $dbw->update(
2478                         'page',
2479                         array( 'page_touched' => $dbw->timestamp() ),
2480                         $this->pageCond(),
2481                         __METHOD__
2482                 );
2483                 HTMLFileCache::clearFileCache( $this );
2484                 return $success;
2485         }
2486
2487         /**
2488          * Prefix some arbitrary text with the namespace or interwiki prefix
2489          * of this object
2490          *
2491          * @param $name String the text
2492          * @return String the prefixed text
2493          * @private
2494          */
2495         private function prefix( $name ) {
2496                 $p = '';
2497                 if ( $this->mInterwiki != '' ) {
2498                         $p = $this->mInterwiki . ':';
2499                 }
2500
2501                 if ( 0 != $this->mNamespace ) {
2502                         $p .= $this->getNsText() . ':';
2503                 }
2504                 return $p . $name;
2505         }
2506
2507         /**
2508          * Returns a simple regex that will match on characters and sequences invalid in titles.
2509          * Note that this doesn't pick up many things that could be wrong with titles, but that
2510          * replacing this regex with something valid will make many titles valid.
2511          *
2512          * @return String regex string
2513          */
2514         static function getTitleInvalidRegex() {
2515                 static $rxTc = false;
2516                 if ( !$rxTc ) {
2517                         # Matching titles will be held as illegal.
2518                         $rxTc = '/' .
2519                                 # Any character not allowed is forbidden...
2520                                 '[^' . Title::legalChars() . ']' .
2521                                 # URL percent encoding sequences interfere with the ability
2522                                 # to round-trip titles -- you can't link to them consistently.
2523                                 '|%[0-9A-Fa-f]{2}' .
2524                                 # XML/HTML character references produce similar issues.
2525                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2526                                 '|&#[0-9]+;' .
2527                                 '|&#x[0-9A-Fa-f]+;' .
2528                                 '/S';
2529                 }
2530
2531                 return $rxTc;
2532         }
2533
2534         /**
2535          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2536          *
2537          * @param $text String containing title to capitalize
2538          * @param $ns int namespace index, defaults to NS_MAIN
2539          * @return String containing capitalized title
2540          */
2541         public static function capitalize( $text, $ns = NS_MAIN ) {
2542                 global $wgContLang;
2543
2544                 if ( MWNamespace::isCapitalized( $ns ) ) {
2545                         return $wgContLang->ucfirst( $text );
2546                 } else {
2547                         return $text;
2548                 }
2549         }
2550
2551         /**
2552          * Secure and split - main initialisation function for this object
2553          *
2554          * Assumes that mDbkeyform has been set, and is urldecoded
2555          * and uses underscores, but not otherwise munged.  This function
2556          * removes illegal characters, splits off the interwiki and
2557          * namespace prefixes, sets the other forms, and canonicalizes
2558          * everything.
2559          *
2560          * @return Bool true on success
2561          */
2562         private function secureAndSplit() {
2563                 global $wgContLang, $wgLocalInterwiki;
2564
2565                 # Initialisation
2566                 $this->mInterwiki = $this->mFragment = '';
2567                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2568
2569                 $dbkey = $this->mDbkeyform;
2570
2571                 # Strip Unicode bidi override characters.
2572                 # Sometimes they slip into cut-n-pasted page titles, where the
2573                 # override chars get included in list displays.
2574                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2575
2576                 # Clean up whitespace
2577                 # Note: use of the /u option on preg_replace here will cause
2578                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2579                 # conveniently disabling them.
2580                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2581                 $dbkey = trim( $dbkey, '_' );
2582
2583                 if ( $dbkey == '' ) {
2584                         return false;
2585                 }
2586
2587                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2588                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2589                         return false;
2590                 }
2591
2592                 $this->mDbkeyform = $dbkey;
2593
2594                 # Initial colon indicates main namespace rather than specified default
2595                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2596                 if ( ':' == $dbkey { 0 } ) {
2597                         $this->mNamespace = NS_MAIN;
2598                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2599                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2600                 }
2601
2602                 # Namespace or interwiki prefix
2603                 $firstPass = true;
2604                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2605                 do {
2606                         $m = array();
2607                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2608                                 $p = $m[1];
2609                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2610                                         # Ordinary namespace
2611                                         $dbkey = $m[2];
2612                                         $this->mNamespace = $ns;
2613                                         # For Talk:X pages, check if X has a "namespace" prefix
2614                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2615                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2616                                                         # Disallow Talk:File:x type titles...
2617                                                         return false;
2618                                                 } else if ( Interwiki::isValidInterwiki( $x[1] ) ) {
2619                                                         # Disallow Talk:Interwiki:x type titles...
2620                                                         return false;
2621                                                 }
2622                                         }
2623                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2624                                         if ( !$firstPass ) {
2625                                                 # Can't make a local interwiki link to an interwiki link.
2626                                                 # That's just crazy!
2627                                                 return false;
2628                                         }
2629
2630                                         # Interwiki link
2631                                         $dbkey = $m[2];
2632                                         $this->mInterwiki = $wgContLang->lc( $p );
2633
2634                                         # Redundant interwiki prefix to the local wiki
2635                                         if ( $wgLocalInterwiki !== false
2636                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2637                                         {
2638                                                 if ( $dbkey == '' ) {
2639                                                         # Can't have an empty self-link
2640                                                         return false;
2641                                                 }
2642                                                 $this->mInterwiki = '';
2643                                                 $firstPass = false;
2644                                                 # Do another namespace split...
2645                                                 continue;
2646                                         }
2647
2648                                         # If there's an initial colon after the interwiki, that also
2649                                         # resets the default namespace
2650                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2651                                                 $this->mNamespace = NS_MAIN;
2652                                                 $dbkey = substr( $dbkey, 1 );
2653                                         }
2654                                 }
2655                                 # If there's no recognized interwiki or namespace,
2656                                 # then let the colon expression be part of the title.
2657                         }
2658                         break;
2659                 } while ( true );
2660
2661                 # We already know that some pages won't be in the database!
2662                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2663                         $this->mArticleID = 0;
2664                 }
2665                 $fragment = strstr( $dbkey, '#' );
2666                 if ( false !== $fragment ) {
2667                         $this->setFragment( $fragment );
2668                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2669                         # remove whitespace again: prevents "Foo_bar_#"
2670                         # becoming "Foo_bar_"
2671                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2672                 }
2673
2674                 # Reject illegal characters.
2675                 $rxTc = self::getTitleInvalidRegex();
2676                 if ( preg_match( $rxTc, $dbkey ) ) {
2677                         return false;
2678                 }
2679
2680                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2681                 # reachable due to the way web browsers deal with 'relative' URLs.
2682                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2683                 if ( strpos( $dbkey, '.' ) !== false &&
2684                          ( $dbkey === '.' || $dbkey === '..' ||
2685                            strpos( $dbkey, './' ) === 0  ||
2686                            strpos( $dbkey, '../' ) === 0 ||
2687                            strpos( $dbkey, '/./' ) !== false ||
2688                            strpos( $dbkey, '/../' ) !== false  ||
2689                            substr( $dbkey, -2 ) == '/.' ||
2690                            substr( $dbkey, -3 ) == '/..' ) )
2691                 {
2692                         return false;
2693                 }
2694
2695                 # Magic tilde sequences? Nu-uh!
2696                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2697                         return false;
2698                 }
2699
2700                 # Limit the size of titles to 255 bytes. This is typically the size of the
2701                 # underlying database field. We make an exception for special pages, which
2702                 # don't need to be stored in the database, and may edge over 255 bytes due
2703                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2704                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2705                   strlen( $dbkey ) > 512 )
2706                 {
2707                         return false;
2708                 }
2709
2710                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2711                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2712                 # other site might be case-sensitive.
2713                 $this->mUserCaseDBKey = $dbkey;
2714                 if ( $this->mInterwiki == '' ) {
2715                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2716                 }
2717
2718                 # Can't make a link to a namespace alone... "empty" local links can only be
2719                 # self-links with a fragment identifier.
2720                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2721                         return false;
2722                 }
2723
2724                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2725                 // IP names are not allowed for accounts, and can only be referring to
2726                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2727                 // there are numerous ways to present the same IP. Having sp:contribs scan
2728                 // them all is silly and having some show the edits and others not is
2729                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2730                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2731                         ? IP::sanitizeIP( $dbkey )
2732                         : $dbkey;
2733
2734                 // Any remaining initial :s are illegal.
2735                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2736                         return false;
2737                 }
2738
2739                 # Fill fields
2740                 $this->mDbkeyform = $dbkey;
2741                 $this->mUrlform = wfUrlencode( $dbkey );
2742
2743                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2744
2745                 return true;
2746         }
2747
2748         /**
2749          * Set the fragment for this title. Removes the first character from the
2750          * specified fragment before setting, so it assumes you're passing it with
2751          * an initial "#".
2752          *
2753          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2754          * Still in active use privately.
2755          *
2756          * @param $fragment String text
2757          */
2758         public function setFragment( $fragment ) {
2759                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2760         }
2761
2762         /**
2763          * Get a Title object associated with the talk page of this article
2764          *
2765          * @return Title the object for the talk page
2766          */
2767         public function getTalkPage() {
2768                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2769         }
2770
2771         /**
2772          * Get a title object associated with the subject page of this
2773          * talk page
2774          *
2775          * @return Title the object for the subject page
2776          */
2777         public function getSubjectPage() {
2778                 // Is this the same title?
2779                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2780                 if ( $this->getNamespace() == $subjectNS ) {
2781                         return $this;
2782                 }
2783                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2784         }
2785
2786         /**
2787          * Get an array of Title objects linking to this Title
2788          * Also stores the IDs in the link cache.
2789          *
2790          * WARNING: do not use this function on arbitrary user-supplied titles!
2791          * On heavily-used templates it will max out the memory.
2792          *
2793          * @param $options Array: may be FOR UPDATE
2794          * @param $table String: table name
2795          * @param $prefix String: fields prefix
2796          * @return Array of Title objects linking here
2797          */
2798         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2799                 $linkCache = LinkCache::singleton();
2800
2801                 if ( count( $options ) > 0 ) {
2802                         $db = wfGetDB( DB_MASTER );
2803                 } else {
2804                         $db = wfGetDB( DB_SLAVE );
2805                 }
2806
2807                 $res = $db->select(
2808                         array( 'page', $table ),
2809                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2810                         array(
2811                                 "{$prefix}_from=page_id",
2812                                 "{$prefix}_namespace" => $this->getNamespace(),
2813                                 "{$prefix}_title"     => $this->getDBkey() ),
2814                         __METHOD__,
2815                         $options
2816                 );
2817
2818                 $retVal = array();
2819                 if ( $db->numRows( $res ) ) {
2820                         foreach ( $res as $row ) {
2821                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2822                                 if ( $titleObj ) {
2823                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2824                                         $retVal[] = $titleObj;
2825                                 }
2826                         }
2827                 }
2828                 return $retVal;
2829         }
2830
2831         /**
2832          * Get an array of Title objects using this Title as a template
2833          * Also stores the IDs in the link cache.
2834          *
2835          * WARNING: do not use this function on arbitrary user-supplied titles!
2836          * On heavily-used templates it will max out the memory.
2837          *
2838          * @param $options Array: may be FOR UPDATE
2839          * @return Array of Title the Title objects linking here
2840          */
2841         public function getTemplateLinksTo( $options = array() ) {
2842                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2843         }
2844
2845         /**
2846          * Get an array of Title objects referring to non-existent articles linked from this page
2847          *
2848          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2849          * @return Array of Title the Title objects
2850          */
2851         public function getBrokenLinksFrom() {
2852                 if ( $this->getArticleId() == 0 ) {
2853                         # All links from article ID 0 are false positives
2854                         return array();
2855                 }
2856
2857                 $dbr = wfGetDB( DB_SLAVE );
2858                 $res = $dbr->select(
2859                         array( 'page', 'pagelinks' ),
2860                         array( 'pl_namespace', 'pl_title' ),
2861                         array(
2862                                 'pl_from' => $this->getArticleId(),
2863                                 'page_namespace IS NULL'
2864                         ),
2865                         __METHOD__, array(),
2866                         array(
2867                                 'page' => array(
2868                                         'LEFT JOIN',
2869                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2870                                 )
2871                         )
2872                 );
2873
2874                 $retVal = array();
2875                 foreach ( $res as $row ) {
2876                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2877                 }
2878                 return $retVal;
2879         }
2880
2881
2882         /**
2883          * Get a list of URLs to purge from the Squid cache when this
2884          * page changes
2885          *
2886          * @return Array of String the URLs
2887          */
2888         public function getSquidURLs() {
2889                 global $wgContLang;
2890
2891                 $urls = array(
2892                         $this->getInternalURL(),
2893                         $this->getInternalURL( 'action=history' )
2894                 );
2895
2896                 // purge variant urls as well
2897                 if ( $wgContLang->hasVariants() ) {
2898                         $variants = $wgContLang->getVariants();
2899                         foreach ( $variants as $vCode ) {
2900                                 $urls[] = $this->getInternalURL( '', $vCode );
2901                         }
2902                 }
2903
2904                 return $urls;
2905         }
2906
2907         /**
2908          * Purge all applicable Squid URLs
2909          */
2910         public function purgeSquid() {
2911                 global $wgUseSquid;
2912                 if ( $wgUseSquid ) {
2913                         $urls = $this->getSquidURLs();
2914                         $u = new SquidUpdate( $urls );
2915                         $u->doUpdate();
2916                 }
2917         }
2918
2919         /**
2920          * Move this page without authentication
2921          *
2922          * @param $nt Title the new page Title
2923          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
2924          */
2925         public function moveNoAuth( &$nt ) {
2926                 return $this->moveTo( $nt, false );
2927         }
2928
2929         /**
2930          * Check whether a given move operation would be valid.
2931          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2932          *
2933          * @param $nt Title the new title
2934          * @param $auth Bool indicates whether $wgUser's permissions
2935          *  should be checked
2936          * @param $reason String is the log summary of the move, used for spam checking
2937          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
2938          */
2939         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2940                 global $wgUser;
2941
2942                 $errors = array();
2943                 if ( !$nt ) {
2944                         // Normally we'd add this to $errors, but we'll get
2945                         // lots of syntax errors if $nt is not an object
2946                         return array( array( 'badtitletext' ) );
2947                 }
2948                 if ( $this->equals( $nt ) ) {
2949                         $errors[] = array( 'selfmove' );
2950                 }
2951                 if ( !$this->isMovable() ) {
2952                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2953                 }
2954                 if ( $nt->getInterwiki() != '' ) {
2955                         $errors[] = array( 'immobile-target-namespace-iw' );
2956                 }
2957                 if ( !$nt->isMovable() ) {
2958                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
2959                 }
2960
2961                 $oldid = $this->getArticleID();
2962                 $newid = $nt->getArticleID();
2963
2964                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2965                         $errors[] = array( 'articleexists' );
2966                 }
2967                 if ( ( $this->getDBkey() == '' ) ||
2968                          ( !$oldid ) ||
2969                          ( $nt->getDBkey() == '' ) ) {
2970                         $errors[] = array( 'badarticleerror' );
2971                 }
2972
2973                 // Image-specific checks
2974                 if ( $this->getNamespace() == NS_FILE ) {
2975                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
2976                 }
2977
2978                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
2979                         $errors[] = array( 'nonfile-cannot-move-to-file' );
2980                 }
2981
2982                 if ( $auth ) {
2983                         $errors = wfMergeErrorArrays( $errors,
2984                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
2985                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
2986                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
2987                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
2988                 }
2989
2990                 $match = EditPage::matchSummarySpamRegex( $reason );
2991                 if ( $match !== false ) {
2992                         // This is kind of lame, won't display nice
2993                         $errors[] = array( 'spamprotectiontext' );
2994                 }
2995
2996                 $err = null;
2997                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
2998                         $errors[] = array( 'hookaborted', $err );
2999                 }
3000
3001                 # The move is allowed only if (1) the target doesn't exist, or
3002                 # (2) the target is a redirect to the source, and has no history
3003                 # (so we can undo bad moves right after they're done).
3004
3005                 if ( 0 != $newid ) { # Target exists; check for validity
3006                         if ( !$this->isValidMoveTarget( $nt ) ) {
3007                                 $errors[] = array( 'articleexists' );
3008                         }
3009                 } else {
3010                         $tp = $nt->getTitleProtection();
3011                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3012                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3013                                 $errors[] = array( 'cantmove-titleprotected' );
3014                         }
3015                 }
3016                 if ( empty( $errors ) ) {
3017                         return true;
3018                 }
3019                 return $errors;
3020         }
3021
3022         /**
3023          * Check if the requested move target is a valid file move target
3024          * @param Title $nt Target title
3025          * @return array List of errors
3026          */
3027         protected function validateFileMoveOperation( $nt ) {
3028                 global $wgUser;
3029
3030                 $errors = array();
3031
3032                 if ( $nt->getNamespace() != NS_FILE ) {
3033                         $errors[] = array( 'imagenocrossnamespace' );
3034                 }
3035
3036                 $file = wfLocalFile( $this );
3037                 if ( $file->exists() ) {
3038                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3039                                 $errors[] = array( 'imageinvalidfilename' );
3040                         }
3041                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3042                                 $errors[] = array( 'imagetypemismatch' );
3043                         }
3044                 }
3045
3046                 $destFile = wfLocalFile( $nt );
3047                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3048                         $errors[] = array( 'file-exists-sharedrepo' );
3049                 }
3050
3051                 return $errors;
3052         }
3053
3054         /**
3055          * Move a title to a new location
3056          *
3057          * @param $nt Title the new title
3058          * @param $auth Bool indicates whether $wgUser's permissions
3059          *  should be checked
3060          * @param $reason String the reason for the move
3061          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3062          *  Ignored if the user doesn't have the suppressredirect right.
3063          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3064          */
3065         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3066                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3067                 if ( is_array( $err ) ) {
3068                         return $err;
3069                 }
3070
3071                 // If it is a file, move it first. It is done before all other moving stuff is
3072                 // done because it's hard to revert
3073                 $dbw = wfGetDB( DB_MASTER );
3074                 if ( $this->getNamespace() == NS_FILE ) {
3075                         $file = wfLocalFile( $this );
3076                         if ( $file->exists() ) {
3077                                 $status = $file->move( $nt );
3078                                 if ( !$status->isOk() ) {
3079                                         return $status->getErrorsArray();
3080                                 }
3081                         }
3082                 }
3083
3084                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3085                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3086                 $protected = $this->isProtected();
3087                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3088
3089                 // Do the actual move
3090                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3091                 if ( is_array( $err ) ) {
3092                         # FIXME: What about the File we have already moved?
3093                         $dbw->rollback();
3094                         return $err;
3095                 }
3096
3097                 $redirid = $this->getArticleID();
3098
3099                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3100                 // cl_timestamp, which may disturb time-based lists on some sites.
3101                 $prefixes = $dbw->select(
3102                         'categorylinks',
3103                         array( 'cl_sortkey_prefix', 'cl_to' ),
3104                         array( 'cl_from' => $pageid ),
3105                         __METHOD__
3106                 );
3107                 foreach ( $prefixes as $prefixRow ) {
3108                         $prefix = $prefixRow->cl_sortkey_prefix;
3109                         $catTo = $prefixRow->cl_to;
3110                         $dbw->update( 'categorylinks',
3111                                 array(
3112                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3113                                                 $nt->getCategorySortkey( $prefix ) ),
3114                                         'cl_timestamp=cl_timestamp' ),
3115                                 array(
3116                                         'cl_from' => $pageid,
3117                                         'cl_to' => $catTo ),
3118                                 __METHOD__
3119                         );
3120                 }
3121
3122                 if ( $protected ) {
3123                         # Protect the redirect title as the title used to be...
3124                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3125                                 array(
3126                                         'pr_page'    => $redirid,
3127                                         'pr_type'    => 'pr_type',
3128                                         'pr_level'   => 'pr_level',
3129                                         'pr_cascade' => 'pr_cascade',
3130                                         'pr_user'    => 'pr_user',
3131                                         'pr_expiry'  => 'pr_expiry'
3132                                 ),
3133                                 array( 'pr_page' => $pageid ),
3134                                 __METHOD__,
3135                                 array( 'IGNORE' )
3136                         );
3137                         # Update the protection log
3138                         $log = new LogPage( 'protect' );
3139                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3140                         if ( $reason ) {
3141                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3142                         }
3143                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) ); // FIXME: $params?
3144                 }
3145
3146                 # Update watchlists
3147                 $oldnamespace = $this->getNamespace() & ~1;
3148                 $newnamespace = $nt->getNamespace() & ~1;
3149                 $oldtitle = $this->getDBkey();
3150                 $newtitle = $nt->getDBkey();
3151
3152                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3153                         WatchedItem::duplicateEntries( $this, $nt );
3154                 }
3155
3156                 # Update search engine
3157                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3158                 $u->doUpdate();
3159                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3160                 $u->doUpdate();
3161
3162                 $dbw->commit();
3163
3164                 # Update site_stats
3165                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3166                         # No longer a content page
3167                         # Not viewed, edited, removing
3168                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3169                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3170                         # Now a content page
3171                         # Not viewed, edited, adding
3172                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3173                 } elseif ( $pageCountChange ) {
3174                         # Redirect added
3175                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3176                 } else {
3177                         # Nothing special
3178                         $u = false;
3179                 }
3180                 if ( $u ) {
3181                         $u->doUpdate();
3182                 }
3183                 # Update message cache for interface messages
3184                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3185                         # @bug 17860: old article can be deleted, if this the case,
3186                         # delete it from message cache
3187                         if ( $this->getArticleID() === 0 ) {
3188                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3189                         } else {
3190                                 $oldarticle = new Article( $this );
3191                                 MessageCache::singleton()->replace( $this->getDBkey(), $oldarticle->getContent() );
3192                         }
3193                 }
3194                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3195                         $newarticle = new Article( $nt );
3196                         MessageCache::singleton()->replace( $nt->getDBkey(), $newarticle->getContent() );
3197                 }
3198
3199                 global $wgUser;
3200                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3201                 return true;
3202         }
3203
3204         /**
3205          * Move page to a title which is either a redirect to the
3206          * source page or nonexistent
3207          *
3208          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3209          * @param $reason String The reason for the move
3210          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3211          *   if the user doesn't have the suppressredirect right
3212          */
3213         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3214                 global $wgUser, $wgContLang;
3215
3216                 $moveOverRedirect = $nt->exists();
3217
3218                 $commentMsg = ( $moveOverRedirect ? '1movedto2_redir' : '1movedto2' );
3219                 $comment = wfMsgForContent( $commentMsg, $this->getPrefixedText(), $nt->getPrefixedText() );
3220
3221                 if ( $reason ) {
3222                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3223                 }
3224                 # Truncate for whole multibyte characters.
3225                 $comment = $wgContLang->truncate( $comment, 255 );
3226
3227                 $oldid = $this->getArticleID();
3228                 $latest = $this->getLatestRevID();
3229
3230                 $oldns = $this->getNamespace();
3231                 $olddbk = $this->getDBkey();
3232
3233                 $dbw = wfGetDB( DB_MASTER );
3234
3235                 if ( $moveOverRedirect ) {
3236                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3237
3238                         $newid = $nt->getArticleID();
3239                         $newns = $nt->getNamespace();
3240                         $newdbk = $nt->getDBkey();
3241
3242                         # Delete the old redirect. We don't save it to history since
3243                         # by definition if we've got here it's rather uninteresting.
3244                         # We have to remove it so that the next step doesn't trigger
3245                         # a conflict on the unique namespace+title index...
3246                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3247                         if ( !$dbw->cascadingDeletes() ) {
3248                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3249                                 global $wgUseTrackbacks;
3250                                 if ( $wgUseTrackbacks ) {
3251                                         $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3252                                 }
3253                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3254                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3255                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3256                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3257                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3258                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3259                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3260                         }
3261                         // If the target page was recently created, it may have an entry in recentchanges still
3262                         $dbw->delete( 'recentchanges',
3263                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3264                                 __METHOD__
3265                         );
3266                 }
3267
3268                 # Save a null revision in the page's history notifying of the move
3269                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3270                 if ( !is_object( $nullRevision ) ) {
3271                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3272                 }
3273                 $nullRevId = $nullRevision->insertOn( $dbw );
3274
3275                 # Change the name of the target page:
3276                 $dbw->update( 'page',
3277                         /* SET */ array(
3278                                 'page_touched'   => $dbw->timestamp(),
3279                                 'page_namespace' => $nt->getNamespace(),
3280                                 'page_title'     => $nt->getDBkey(),
3281                                 'page_latest'    => $nullRevId,
3282                         ),
3283                         /* WHERE */ array( 'page_id' => $oldid ),
3284                         __METHOD__
3285                 );
3286                 $nt->resetArticleID( $oldid );
3287
3288                 $article = new Article( $nt );
3289                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3290
3291                 # Recreate the redirect, this time in the other direction.
3292                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3293                         $mwRedir = MagicWord::get( 'redirect' );
3294                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3295                         $redirectArticle = new Article( $this );
3296                         $newid = $redirectArticle->insertOn( $dbw );
3297                         $redirectRevision = new Revision( array(
3298                                 'page'    => $newid,
3299                                 'comment' => $comment,
3300                                 'text'    => $redirectText ) );
3301                         $redirectRevision->insertOn( $dbw );
3302                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3303
3304                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3305
3306                         # Now, we record the link from the redirect to the new title.
3307                         # It should have no other outgoing links...
3308                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3309                         $dbw->insert( 'pagelinks',
3310                                 array(
3311                                         'pl_from'      => $newid,
3312                                         'pl_namespace' => $nt->getNamespace(),
3313                                         'pl_title'     => $nt->getDBkey() ),
3314                                 __METHOD__ );
3315                         $redirectSuppressed = false;
3316                 } else {
3317                         // Get rid of old new page entries in Special:NewPages and RC.
3318                         // Needs to be before $this->resetArticleID( 0 ).
3319                         $dbw->delete( 'recentchanges', array(
3320                                         'rc_timestamp' => $dbw->timestamp( $this->getEarliestRevTime() ),
3321                                         'rc_namespace' => $oldns,
3322                                         'rc_title' => $olddbk,
3323                                         'rc_new' => 1
3324                                 ),
3325                                 __METHOD__
3326                         );
3327
3328                         $this->resetArticleID( 0 );
3329                         $redirectSuppressed = true;
3330                 }
3331
3332                 # Log the move
3333                 $log = new LogPage( 'move' );
3334                 $logType = ( $moveOverRedirect ? 'move_redir' : 'move' );
3335                 $log->addEntry( $logType, $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3336
3337                 # Purge caches for old and new titles
3338                 if ( $moveOverRedirect ) {
3339                         # A simple purge is enough when moving over a redirect
3340                         $nt->purgeSquid();
3341                 } else {
3342                         # Purge caches as per article creation, including any pages that link to this title
3343                         Article::onArticleCreate( $nt );
3344                 }
3345                 $this->purgeSquid();
3346         }
3347
3348         /**
3349          * Move this page's subpages to be subpages of $nt
3350          *
3351          * @param $nt Title Move target
3352          * @param $auth bool Whether $wgUser's permissions should be checked
3353          * @param $reason string The reason for the move
3354          * @param $createRedirect bool Whether to create redirects from the old subpages to
3355          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3356          * @return mixed array with old page titles as keys, and strings (new page titles) or
3357          *     arrays (errors) as values, or an error array with numeric indices if no pages
3358          *     were moved
3359          */
3360         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3361                 global $wgMaximumMovedPages;
3362                 // Check permissions
3363                 if ( !$this->userCan( 'move-subpages' ) ) {
3364                         return array( 'cant-move-subpages' );
3365                 }
3366                 // Do the source and target namespaces support subpages?
3367                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3368                         return array( 'namespace-nosubpages',
3369                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3370                 }
3371                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3372                         return array( 'namespace-nosubpages',
3373                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3374                 }
3375
3376                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3377                 $retval = array();
3378                 $count = 0;
3379                 foreach ( $subpages as $oldSubpage ) {
3380                         $count++;
3381                         if ( $count > $wgMaximumMovedPages ) {
3382                                 $retval[$oldSubpage->getPrefixedTitle()] =
3383                                                 array( 'movepage-max-pages',
3384                                                         $wgMaximumMovedPages );
3385                                 break;
3386                         }
3387
3388                         // We don't know whether this function was called before
3389                         // or after moving the root page, so check both
3390                         // $this and $nt
3391                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3392                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3393                         {
3394                                 // When moving a page to a subpage of itself,
3395                                 // don't move it twice
3396                                 continue;
3397                         }
3398                         $newPageName = preg_replace(
3399                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3400                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3401                                         $oldSubpage->getDBkey() );
3402                         if ( $oldSubpage->isTalkPage() ) {
3403                                 $newNs = $nt->getTalkPage()->getNamespace();
3404                         } else {
3405                                 $newNs = $nt->getSubjectPage()->getNamespace();
3406                         }
3407                         # Bug 14385: we need makeTitleSafe because the new page names may
3408                         # be longer than 255 characters.
3409                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3410
3411                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3412                         if ( $success === true ) {
3413                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3414                         } else {
3415                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3416                         }
3417                 }
3418                 return $retval;
3419         }
3420
3421         /**
3422          * Checks if this page is just a one-rev redirect.
3423          * Adds lock, so don't use just for light purposes.
3424          *
3425          * @return Bool
3426          */
3427         public function isSingleRevRedirect() {
3428                 $dbw = wfGetDB( DB_MASTER );
3429                 # Is it a redirect?
3430                 $row = $dbw->selectRow( 'page',
3431                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3432                         $this->pageCond(),
3433                         __METHOD__,
3434                         array( 'FOR UPDATE' )
3435                 );
3436                 # Cache some fields we may want
3437                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3438                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3439                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3440                 if ( !$this->mRedirect ) {
3441                         return false;
3442                 }
3443                 # Does the article have a history?
3444                 $row = $dbw->selectField( array( 'page', 'revision' ),
3445                         'rev_id',
3446                         array( 'page_namespace' => $this->getNamespace(),
3447                                 'page_title' => $this->getDBkey(),
3448                                 'page_id=rev_page',
3449                                 'page_latest != rev_id'
3450                         ),
3451                         __METHOD__,
3452                         array( 'FOR UPDATE' )
3453                 );
3454                 # Return true if there was no history
3455                 return ( $row === false );
3456         }
3457
3458         /**
3459          * Checks if $this can be moved to a given Title
3460          * - Selects for update, so don't call it unless you mean business
3461          *
3462          * @param $nt Title the new title to check
3463          * @return Bool
3464          */
3465         public function isValidMoveTarget( $nt ) {
3466                 # Is it an existing file?
3467                 if ( $nt->getNamespace() == NS_FILE ) {
3468                         $file = wfLocalFile( $nt );
3469                         if ( $file->exists() ) {
3470                                 wfDebug( __METHOD__ . ": file exists\n" );
3471                                 return false;
3472                         }
3473                 }
3474                 # Is it a redirect with no history?
3475                 if ( !$nt->isSingleRevRedirect() ) {
3476                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3477                         return false;
3478                 }
3479                 # Get the article text
3480                 $rev = Revision::newFromTitle( $nt );
3481                 $text = $rev->getText();
3482                 # Does the redirect point to the source?
3483                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3484                 $m = array();
3485                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3486                         $redirTitle = Title::newFromText( $m[1] );
3487                         if ( !is_object( $redirTitle ) ||
3488                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3489                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3490                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3491                                 return false;
3492                         }
3493                 } else {
3494                         # Fail safe
3495                         wfDebug( __METHOD__ . ": failsafe\n" );
3496                         return false;
3497                 }
3498                 return true;
3499         }
3500
3501         /**
3502          * Can this title be added to a user's watchlist?
3503          *
3504          * @return Bool TRUE or FALSE
3505          */
3506         public function isWatchable() {
3507                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3508         }
3509
3510         /**
3511          * Get categories to which this Title belongs and return an array of
3512          * categories' names.
3513          *
3514          * @return Array of parents in the form:
3515          *        $parent => $currentarticle
3516          */
3517         public function getParentCategories() {
3518                 global $wgContLang;
3519
3520                 $data = array();
3521
3522                 $titleKey = $this->getArticleId();
3523
3524                 if ( $titleKey === 0 ) {
3525                         return $data;
3526                 }
3527
3528                 $dbr = wfGetDB( DB_SLAVE );
3529
3530                 $res = $dbr->select( 'categorylinks', '*',
3531                         array(
3532                                 'cl_from' => $titleKey,
3533                         ),
3534                         __METHOD__,
3535                         array()
3536                 );
3537
3538                 if ( $dbr->numRows( $res ) > 0 ) {
3539                         foreach ( $res as $row ) {
3540                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3541                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3542                         }
3543                 }
3544                 return $data;
3545         }
3546
3547         /**
3548          * Get a tree of parent categories
3549          *
3550          * @param $children Array with the children in the keys, to check for circular refs
3551          * @return Array Tree of parent categories
3552          */
3553         public function getParentCategoryTree( $children = array() ) {
3554                 $stack = array();
3555                 $parents = $this->getParentCategories();
3556
3557                 if ( $parents ) {
3558                         foreach ( $parents as $parent => $current ) {
3559                                 if ( array_key_exists( $parent, $children ) ) {
3560                                         # Circular reference
3561                                         $stack[$parent] = array();
3562                                 } else {
3563                                         $nt = Title::newFromText( $parent );
3564                                         if ( $nt ) {
3565                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3566                                         }
3567                                 }
3568                         }
3569                 }
3570
3571                 return $stack;
3572         }
3573
3574         /**
3575          * Get an associative array for selecting this title from
3576          * the "page" table
3577          *
3578          * @return Array suitable for the $where parameter of DB::select()
3579          */
3580         public function pageCond() {
3581                 if ( $this->mArticleID > 0 ) {
3582                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3583                         return array( 'page_id' => $this->mArticleID );
3584                 } else {
3585                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3586                 }
3587         }
3588
3589         /**
3590          * Get the revision ID of the previous revision
3591          *
3592          * @param $revId Int Revision ID. Get the revision that was before this one.
3593          * @param $flags Int Title::GAID_FOR_UPDATE
3594          * @return Int|Bool Old revision ID, or FALSE if none exists
3595          */
3596         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3597                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3598                 return $db->selectField( 'revision', 'rev_id',
3599                         array(
3600                                 'rev_page' => $this->getArticleId( $flags ),
3601                                 'rev_id < ' . intval( $revId )
3602                         ),
3603                         __METHOD__,
3604                         array( 'ORDER BY' => 'rev_id DESC' )
3605                 );
3606         }
3607
3608         /**
3609          * Get the revision ID of the next revision
3610          *
3611          * @param $revId Int Revision ID. Get the revision that was after this one.
3612          * @param $flags Int Title::GAID_FOR_UPDATE
3613          * @return Int|Bool Next revision ID, or FALSE if none exists
3614          */
3615         public function getNextRevisionID( $revId, $flags = 0 ) {
3616                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3617                 return $db->selectField( 'revision', 'rev_id',
3618                         array(
3619                                 'rev_page' => $this->getArticleId( $flags ),
3620                                 'rev_id > ' . intval( $revId )
3621                         ),
3622                         __METHOD__,
3623                         array( 'ORDER BY' => 'rev_id' )
3624                 );
3625         }
3626
3627         /**
3628          * Get the first revision of the page
3629          *
3630          * @param $flags Int Title::GAID_FOR_UPDATE
3631          * @return Revision|Null if page doesn't exist
3632          */
3633         public function getFirstRevision( $flags = 0 ) {
3634                 $pageId = $this->getArticleId( $flags );
3635                 if ( $pageId ) {
3636                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3637                         $row = $db->selectRow( 'revision', '*',
3638                                 array( 'rev_page' => $pageId ),
3639                                 __METHOD__,
3640                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3641                         );
3642                         if ( $row ) {
3643                                 return new Revision( $row );
3644                         }
3645                 }
3646                 return null;
3647         }
3648
3649         /**
3650          * Get the oldest revision timestamp of this page
3651          *
3652          * @param $flags Int Title::GAID_FOR_UPDATE
3653          * @return String: MW timestamp
3654          */
3655         public function getEarliestRevTime( $flags = 0 ) {
3656                 $rev = $this->getFirstRevision( $flags );
3657                 return $rev ? $rev->getTimestamp() : null;
3658         }
3659
3660         /**
3661          * Check if this is a new page
3662          *
3663          * @return bool
3664          */
3665         public function isNewPage() {
3666                 $dbr = wfGetDB( DB_SLAVE );
3667                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3668         }
3669
3670         /**
3671          * Get the number of revisions between the given revision.
3672          * Used for diffs and other things that really need it.
3673          *
3674          * @param $old int|Revision Old revision or rev ID (first before range)
3675          * @param $new int|Revision New revision or rev ID (first after range)
3676          * @return Int Number of revisions between these revisions.
3677          */
3678         public function countRevisionsBetween( $old, $new ) {
3679                 if ( !( $old instanceof Revision ) ) {
3680                         $old = Revision::newFromTitle( $this, (int)$old );
3681                 }
3682                 if ( !( $new instanceof Revision ) ) {
3683                         $new = Revision::newFromTitle( $this, (int)$new );
3684                 }
3685                 if ( !$old || !$new ) {
3686                         return 0; // nothing to compare
3687                 }
3688                 $dbr = wfGetDB( DB_SLAVE );
3689                 return (int)$dbr->selectField( 'revision', 'count(*)',
3690                         array(
3691                                 'rev_page' => $this->getArticleId(),
3692                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3693                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3694                         ),
3695                         __METHOD__
3696                 );
3697         }
3698
3699         /**
3700          * Get the number of authors between the given revision IDs.
3701          * Used for diffs and other things that really need it.
3702          *
3703          * @param $old int|Revision Old revision or rev ID (first before range)
3704          * @param $new int|Revision New revision or rev ID (first after range)
3705          * @param $limit Int Maximum number of authors
3706          * @return Int Number of revision authors between these revisions.
3707          */
3708         public function countAuthorsBetween( $old, $new, $limit ) {
3709                 if ( !( $old instanceof Revision ) ) {
3710                         $old = Revision::newFromTitle( $this, (int)$old );
3711                 }
3712                 if ( !( $new instanceof Revision ) ) {
3713                         $new = Revision::newFromTitle( $this, (int)$new );
3714                 }
3715                 if ( !$old || !$new ) {
3716                         return 0; // nothing to compare
3717                 }
3718                 $dbr = wfGetDB( DB_SLAVE );
3719                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
3720                         array(
3721                                 'rev_page' => $this->getArticleID(),
3722                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3723                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3724                         ), __METHOD__,
3725                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
3726                 );
3727                 return (int)$dbr->numRows( $res );
3728         }
3729
3730         /**
3731          * Compare with another title.
3732          *
3733          * @param $title Title
3734          * @return Bool
3735          */
3736         public function equals( Title $title ) {
3737                 // Note: === is necessary for proper matching of number-like titles.
3738                 return $this->getInterwiki() === $title->getInterwiki()
3739                         && $this->getNamespace() == $title->getNamespace()
3740                         && $this->getDBkey() === $title->getDBkey();
3741         }
3742
3743         /**
3744          * Callback for usort() to do title sorts by (namespace, title)
3745          *
3746          * @param $a Title
3747          * @param $b Title
3748          *
3749          * @return Integer: result of string comparison, or namespace comparison
3750          */
3751         public static function compare( $a, $b ) {
3752                 if ( $a->getNamespace() == $b->getNamespace() ) {
3753                         return strcmp( $a->getText(), $b->getText() );
3754                 } else {
3755                         return $a->getNamespace() - $b->getNamespace();
3756                 }
3757         }
3758
3759         /**
3760          * Return a string representation of this title
3761          *
3762          * @return String representation of this title
3763          */
3764         public function __toString() {
3765                 return $this->getPrefixedText();
3766         }
3767
3768         /**
3769          * Check if page exists.  For historical reasons, this function simply
3770          * checks for the existence of the title in the page table, and will
3771          * thus return false for interwiki links, special pages and the like.
3772          * If you want to know if a title can be meaningfully viewed, you should
3773          * probably call the isKnown() method instead.
3774          *
3775          * @return Bool
3776          */
3777         public function exists() {
3778                 return $this->getArticleId() != 0;
3779         }
3780
3781         /**
3782          * Should links to this title be shown as potentially viewable (i.e. as
3783          * "bluelinks"), even if there's no record by this title in the page
3784          * table?
3785          *
3786          * This function is semi-deprecated for public use, as well as somewhat
3787          * misleadingly named.  You probably just want to call isKnown(), which
3788          * calls this function internally.
3789          *
3790          * (ISSUE: Most of these checks are cheap, but the file existence check
3791          * can potentially be quite expensive.  Including it here fixes a lot of
3792          * existing code, but we might want to add an optional parameter to skip
3793          * it and any other expensive checks.)
3794          *
3795          * @return Bool
3796          */
3797         public function isAlwaysKnown() {
3798                 if ( $this->mInterwiki != '' ) {
3799                         return true;  // any interwiki link might be viewable, for all we know
3800                 }
3801                 switch( $this->mNamespace ) {
3802                         case NS_MEDIA:
3803                         case NS_FILE:
3804                                 // file exists, possibly in a foreign repo
3805                                 return (bool)wfFindFile( $this );
3806                         case NS_SPECIAL:
3807                                 // valid special page
3808                                 return SpecialPageFactory::exists( $this->getDBkey() );
3809                         case NS_MAIN:
3810                                 // selflink, possibly with fragment
3811                                 return $this->mDbkeyform == '';
3812                         case NS_MEDIAWIKI:
3813                                 // known system message
3814                                 return $this->getDefaultMessageText() !== false;
3815                         default:
3816                                 return false;
3817                 }
3818         }
3819
3820         /**
3821          * Does this title refer to a page that can (or might) be meaningfully
3822          * viewed?  In particular, this function may be used to determine if
3823          * links to the title should be rendered as "bluelinks" (as opposed to
3824          * "redlinks" to non-existent pages).
3825          *
3826          * @return Bool
3827          */
3828         public function isKnown() {
3829                 return $this->isAlwaysKnown() || $this->exists();
3830         }
3831
3832         /**
3833          * Does this page have source text?
3834          *
3835          * @return Boolean
3836          */
3837         public function hasSourceText() {
3838                 if ( $this->exists() ) {
3839                         return true;
3840                 }
3841
3842                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3843                         // If the page doesn't exist but is a known system message, default
3844                         // message content will be displayed, same for language subpages
3845                         return $this->getDefaultMessageText() !== false;
3846                 }
3847
3848                 return false;
3849         }
3850
3851         /**
3852          * Get the default message text or false if the message doesn't exist
3853          *
3854          * @return String or false
3855          */
3856         public function getDefaultMessageText() {
3857                 global $wgContLang;
3858
3859                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
3860                         return false;
3861                 }
3862
3863                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
3864                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
3865
3866                 if ( $message->exists() ) {
3867                         return $message->plain();
3868                 } else {
3869                         return false;
3870                 }
3871         }
3872
3873         /**
3874          * Is this in a namespace that allows actual pages?
3875          *
3876          * @return Bool
3877          * @internal note -- uses hardcoded namespace index instead of constants
3878          */
3879         public function canExist() {
3880                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3881         }
3882
3883         /**
3884          * Update page_touched timestamps and send squid purge messages for
3885          * pages linking to this title. May be sent to the job queue depending
3886          * on the number of links. Typically called on create and delete.
3887          */
3888         public function touchLinks() {
3889                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3890                 $u->doUpdate();
3891
3892                 if ( $this->getNamespace() == NS_CATEGORY ) {
3893                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3894                         $u->doUpdate();
3895                 }
3896         }
3897
3898         /**
3899          * Get the last touched timestamp
3900          *
3901          * @param $db DatabaseBase: optional db
3902          * @return String last-touched timestamp
3903          */
3904         public function getTouched( $db = null ) {
3905                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3906                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3907                 return $touched;
3908         }
3909
3910         /**
3911          * Get the timestamp when this page was updated since the user last saw it.
3912          *
3913          * @param $user User
3914          * @return String|Null
3915          */
3916         public function getNotificationTimestamp( $user = null ) {
3917                 global $wgUser, $wgShowUpdatedMarker;
3918                 // Assume current user if none given
3919                 if ( !$user ) {
3920                         $user = $wgUser;
3921                 }
3922                 // Check cache first
3923                 $uid = $user->getId();
3924                 // avoid isset here, as it'll return false for null entries
3925                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
3926                         return $this->mNotificationTimestamp[$uid];
3927                 }
3928                 if ( !$uid || !$wgShowUpdatedMarker ) {
3929                         return $this->mNotificationTimestamp[$uid] = false;
3930                 }
3931                 // Don't cache too much!
3932                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3933                         $this->mNotificationTimestamp = array();
3934                 }
3935                 $dbr = wfGetDB( DB_SLAVE );
3936                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3937                         'wl_notificationtimestamp',
3938                         array( 'wl_namespace' => $this->getNamespace(),
3939                                 'wl_title' => $this->getDBkey(),
3940                                 'wl_user' => $user->getId()
3941                         ),
3942                         __METHOD__
3943                 );
3944                 return $this->mNotificationTimestamp[$uid];
3945         }
3946
3947         /**
3948          * Get the trackback URL for this page
3949          *
3950          * @return String Trackback URL
3951          */
3952         public function trackbackURL() {
3953                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3954
3955                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3956                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3957         }
3958
3959         /**
3960          * Get the trackback RDF for this page
3961          *
3962          * @return String Trackback RDF
3963          */
3964         public function trackbackRDF() {
3965                 $url = htmlspecialchars( $this->getFullURL() );
3966                 $title = htmlspecialchars( $this->getText() );
3967                 $tburl = $this->trackbackURL();
3968
3969                 // Autodiscovery RDF is placed in comments so HTML validator
3970                 // won't barf. This is a rather icky workaround, but seems
3971                 // frequently used by this kind of RDF thingy.
3972                 //
3973                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3974                 return "<!--
3975 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3976                  xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3977                  xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3978 <rdf:Description
3979    rdf:about=\"$url\"
3980    dc:identifier=\"$url\"
3981    dc:title=\"$title\"
3982    trackback:ping=\"$tburl\" />
3983 </rdf:RDF>
3984 -->";
3985         }
3986
3987         /**
3988          * Generate strings used for xml 'id' names in monobook tabs
3989          *
3990          * @param $prepend string defaults to 'nstab-'
3991          * @return String XML 'id' name
3992          */
3993         public function getNamespaceKey( $prepend = 'nstab-' ) {
3994                 global $wgContLang;
3995                 // Gets the subject namespace if this title
3996                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
3997                 // Checks if cononical namespace name exists for namespace
3998                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
3999                         // Uses canonical namespace name
4000                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4001                 } else {
4002                         // Uses text of namespace
4003                         $namespaceKey = $this->getSubjectNsText();
4004                 }
4005                 // Makes namespace key lowercase
4006                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4007                 // Uses main
4008                 if ( $namespaceKey == '' ) {
4009                         $namespaceKey = 'main';
4010                 }
4011                 // Changes file to image for backwards compatibility
4012                 if ( $namespaceKey == 'file' ) {
4013                         $namespaceKey = 'image';
4014                 }
4015                 return $prepend . $namespaceKey;
4016         }
4017
4018         /**
4019          * Returns true if this is a special page.
4020          *
4021          * @return boolean
4022          */
4023         public function isSpecialPage() {
4024                 return $this->getNamespace() == NS_SPECIAL;
4025         }
4026
4027         /**
4028          * Returns true if this title resolves to the named special page
4029          *
4030          * @param $name String The special page name
4031          * @return boolean
4032          */
4033         public function isSpecial( $name ) {
4034                 if ( $this->getNamespace() == NS_SPECIAL ) {
4035                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
4036                         if ( $name == $thisName ) {
4037                                 return true;
4038                         }
4039                 }
4040                 return false;
4041         }
4042
4043         /**
4044          * If the Title refers to a special page alias which is not the local default, resolve
4045          * the alias, and localise the name as necessary.  Otherwise, return $this
4046          *
4047          * @return Title
4048          */
4049         public function fixSpecialName() {
4050                 if ( $this->getNamespace() == NS_SPECIAL ) {
4051                         list( $canonicalName, /*...*/ ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
4052                         if ( $canonicalName ) {
4053                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName );
4054                                 if ( $localName != $this->mDbkeyform ) {
4055                                         return Title::makeTitle( NS_SPECIAL, $localName );
4056                                 }
4057                         }
4058                 }
4059                 return $this;
4060         }
4061
4062         /**
4063          * Is this Title in a namespace which contains content?
4064          * In other words, is this a content page, for the purposes of calculating
4065          * statistics, etc?
4066          *
4067          * @return Boolean
4068          */
4069         public function isContentPage() {
4070                 return MWNamespace::isContent( $this->getNamespace() );
4071         }
4072
4073         /**
4074          * Get all extant redirects to this Title
4075          *
4076          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4077          * @return Array of Title redirects to this title
4078          */
4079         public function getRedirectsHere( $ns = null ) {
4080                 $redirs = array();
4081
4082                 $dbr = wfGetDB( DB_SLAVE );
4083                 $where = array(
4084                         'rd_namespace' => $this->getNamespace(),
4085                         'rd_title' => $this->getDBkey(),
4086                         'rd_from = page_id'
4087                 );
4088                 if ( !is_null( $ns ) ) {
4089                         $where['page_namespace'] = $ns;
4090                 }
4091
4092                 $res = $dbr->select(
4093                         array( 'redirect', 'page' ),
4094                         array( 'page_namespace', 'page_title' ),
4095                         $where,
4096                         __METHOD__
4097                 );
4098
4099                 foreach ( $res as $row ) {
4100                         $redirs[] = self::newFromRow( $row );
4101                 }
4102                 return $redirs;
4103         }
4104
4105         /**
4106          * Check if this Title is a valid redirect target
4107          *
4108          * @return Bool
4109          */
4110         public function isValidRedirectTarget() {
4111                 global $wgInvalidRedirectTargets;
4112
4113                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4114                 if ( $this->isSpecial( 'Userlogout' ) ) {
4115                         return false;
4116                 }
4117
4118                 foreach ( $wgInvalidRedirectTargets as $target ) {
4119                         if ( $this->isSpecial( $target ) ) {
4120                                 return false;
4121                         }
4122                 }
4123
4124                 return true;
4125         }
4126
4127         /**
4128          * Get a backlink cache object
4129          *
4130          * @return object BacklinkCache
4131          */
4132         function getBacklinkCache() {
4133                 if ( is_null( $this->mBacklinkCache ) ) {
4134                         $this->mBacklinkCache = new BacklinkCache( $this );
4135                 }
4136                 return $this->mBacklinkCache;
4137         }
4138
4139         /**
4140          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4141          *
4142          * @return Boolean
4143          */
4144         public function canUseNoindex() {
4145                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4146
4147                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4148                         ? $wgContentNamespaces
4149                         : $wgExemptFromUserRobotsControl;
4150
4151                 return !in_array( $this->mNamespace, $bannedNamespaces );
4152
4153         }
4154
4155         /**
4156          * Returns restriction types for the current Title
4157          *
4158          * @return array applicable restriction types
4159          */
4160         public function getRestrictionTypes() {
4161                 if ( $this->getNamespace() == NS_SPECIAL ) {
4162                         return array();
4163                 }
4164
4165                 $types = self::getFilteredRestrictionTypes( $this->exists() );
4166
4167                 if ( $this->getNamespace() != NS_FILE ) {
4168                         # Remove the upload restriction for non-file titles
4169                         $types = array_diff( $types, array( 'upload' ) );
4170                 }
4171
4172                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4173
4174                 wfDebug( __METHOD__ . ': applicable restriction types for ' .
4175                         $this->getPrefixedText() . ' are ' . implode( ',', $types ) . "\n" );
4176
4177                 return $types;
4178         }
4179         /**
4180          * Get a filtered list of all restriction types supported by this wiki.
4181          * @param bool $exists True to get all restriction types that apply to
4182          * titles that do exist, False for all restriction types that apply to
4183          * titles that do not exist
4184          * @return array
4185          */
4186         public static function getFilteredRestrictionTypes( $exists = true ) {
4187                 global $wgRestrictionTypes;
4188                 $types = $wgRestrictionTypes;
4189                 if ( $exists ) {
4190                         # Remove the create restriction for existing titles
4191                         $types = array_diff( $types, array( 'create' ) );
4192                 } else {
4193                         # Only the create and upload restrictions apply to non-existing titles
4194                         $types = array_intersect( $types, array( 'create', 'upload' ) );
4195                 }
4196                 return $types;
4197         }
4198
4199         /**
4200          * Returns the raw sort key to be used for categories, with the specified
4201          * prefix.  This will be fed to Collation::getSortKey() to get a
4202          * binary sortkey that can be used for actual sorting.
4203          *
4204          * @param $prefix string The prefix to be used, specified using
4205          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4206          *   prefix.
4207          * @return string
4208          */
4209         public function getCategorySortkey( $prefix = '' ) {
4210                 $unprefixed = $this->getText();
4211                 if ( $prefix !== '' ) {
4212                         # Separate with a line feed, so the unprefixed part is only used as
4213                         # a tiebreaker when two pages have the exact same prefix.
4214                         # In UCA, tab is the only character that can sort above LF
4215                         # so we strip both of them from the original prefix.
4216                         $prefix = strtr( $prefix, "\n\t", '  ' );
4217                         return "$prefix\n$unprefixed";
4218                 }
4219                 return $unprefixed;
4220         }
4221 }
4222
4223 /**
4224  * A BadTitle is generated in MediaWiki::parseTitle() if the title is invalid; the
4225  * software uses this to display an error page.  Internally it's basically a Title
4226  * for an empty special page
4227  */
4228 class BadTitle extends Title {
4229         public function __construct(){
4230                 $this->mTextform = '';
4231                 $this->mUrlform = '';
4232                 $this->mDbkeyform = '';
4233                 $this->mNamespace = NS_SPECIAL; // Stops talk page link, etc, being shown
4234         }
4235
4236         public function exists(){
4237                 return false;
4238         }
4239
4240         public function getPrefixedText(){
4241                 return '';
4242         }
4243
4244         public function getText(){
4245                 return '';
4246         }
4247
4248         public function getPrefixedURL(){
4249                 return '';
4250         }
4251
4252         public function getPrefixedDBKey(){
4253                 return '';
4254         }
4255 }