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