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         var $mPageLanguage;
  71         // @}
  72
  73
  74         /**
  75          * Constructor
  76          */
  77         /*protected*/ function __construct() { }
  78
  79         /**
  80          * Create a new Title from a prefixed DB key
  81          *
  82          * @param $key String the database key, which has underscores
  83          *      instead of spaces, possibly including namespace and
  84          *      interwiki prefixes
  85          * @return Title, or NULL on an error
  86          */
  87         public static function newFromDBkey( $key ) {
  88                 $t = new Title();
  89                 $t->mDbkeyform = $key;
  90                 if ( $t->secureAndSplit() ) {
  91                         return $t;
  92                 } else {
  93                         return null;
  94                 }
  95         }
  96
  97         /**
  98          * Create a new Title from text, such as what one would find in a link. De-
  99          * codes any HTML entities in the text.
 100          *
 101          * @param $text String the link text; spaces, prefixes, and an
 102          *   initial ':' indicating the main namespace are accepted.
 103          * @param $defaultNamespace Int the namespace to use if none is speci-
 104          *   fied by a prefix.  If you want to force a specific namespace even if
 105          *   $text might begin with a namespace prefix, use makeTitle() or
 106          *   makeTitleSafe().
 107          * @return Title, or null on an error.
 108          */
 109         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 110                 if ( is_object( $text ) ) {
 111                         throw new MWException( 'Title::newFromText given an object' );
 112                 }
 113
 114                 /**
 115                  * Wiki pages often contain multiple links to the same page.
 116                  * Title normalization and parsing can become expensive on
 117                  * pages with many links, so we can save a little time by
 118                  * caching them.
 119                  *
 120                  * In theory these are value objects and won't get changed...
 121                  */
 122                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 123                         return Title::$titleCache[$text];
 124                 }
 125
 126                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 127                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 128
 129                 $t = new Title();
 130                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 131                 $t->mDefaultNamespace = $defaultNamespace;
 132
 133                 static $cachedcount = 0 ;
 134                 if ( $t->secureAndSplit() ) {
 135                         if ( $defaultNamespace == NS_MAIN ) {
 136                                 if ( $cachedcount >= self::CACHE_MAX ) {
 137                                         # Avoid memory leaks on mass operations...
 138                                         Title::$titleCache = array();
 139                                         $cachedcount = 0;
 140                                 }
 141                                 $cachedcount++;
 142                                 Title::$titleCache[$text] =& $t;
 143                         }
 144                         return $t;
 145                 } else {
 146                         $ret = null;
 147                         return $ret;
 148                 }
 149         }
 150
 151         /**
 152          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 153          *
 154          * Example of wrong and broken code:
 155          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 156          *
 157          * Example of right code:
 158          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 159          *
 160          * Create a new Title from URL-encoded text. Ensures that
 161          * the given title's length does not exceed the maximum.
 162          *
 163          * @param $url String the title, as might be taken from a URL
 164          * @return Title the new object, or NULL on an error
 165          */
 166         public static function newFromURL( $url ) {
 167                 global $wgLegalTitleChars;
 168                 $t = new Title();
 169
 170                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 171                 # but some URLs used it as a space replacement and they still come
 172                 # from some external search tools.
 173                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 174                         $url = str_replace( '+', ' ', $url );
 175                 }
 176
 177                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 178                 if ( $t->secureAndSplit() ) {
 179                         return $t;
 180                 } else {
 181                         return null;
 182                 }
 183         }
 184
 185         /**
 186          * Create a new Title from an article ID
 187          *
 188          * @param $id Int the page_id corresponding to the Title to create
 189          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 190          * @return Title the new object, or NULL on an error
 191          */
 192         public static function newFromID( $id, $flags = 0 ) {
 193                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 194                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 195                 if ( $row !== false ) {
 196                         $title = Title::newFromRow( $row );
 197                 } else {
 198                         $title = null;
 199                 }
 200                 return $title;
 201         }
 202
 203         /**
 204          * Make an array of titles from an array of IDs
 205          *
 206          * @param $ids Array of Int Array of IDs
 207          * @return Array of Titles
 208          */
 209         public static function newFromIDs( $ids ) {
 210                 if ( !count( $ids ) ) {
 211                         return array();
 212                 }
 213                 $dbr = wfGetDB( DB_SLAVE );
 214
 215                 $res = $dbr->select(
 216                         'page',
 217                         array(
 218                                 'page_namespace', 'page_title', 'page_id',
 219                                 'page_len', 'page_is_redirect', 'page_latest',
 220                         ),
 221                         array( 'page_id' => $ids ),
 222                         __METHOD__
 223                 );
 224
 225                 $titles = array();
 226                 foreach ( $res as $row ) {
 227                         $titles[] = Title::newFromRow( $row );
 228                 }
 229                 return $titles;
 230         }
 231
 232         /**
 233          * Make a Title object from a DB row
 234          *
 235          * @param $row Object database row (needs at least page_title,page_namespace)
 236          * @return Title corresponding Title
 237          */
 238         public static function newFromRow( $row ) {
 239                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 240
 241                 $t->mArticleID = isset( $row->page_id ) ? intval( $row->page_id ) : -1;
 242                 $t->mLength = isset( $row->page_len ) ? intval( $row->page_len ) : -1;
 243                 $t->mRedirect = isset( $row->page_is_redirect ) ? (bool)$row->page_is_redirect : null;
 244                 $t->mLatestID = isset( $row->page_latest ) ? intval( $row->page_latest ) : false;
 245
 246                 return $t;
 247         }
 248
 249         /**
 250          * Create a new Title from a namespace index and a DB key.
 251          * It's assumed that $ns and $title are *valid*, for instance when
 252          * they came directly from the database or a special page name.
 253          * For convenience, spaces are converted to underscores so that
 254          * eg user_text fields can be used directly.
 255          *
 256          * @param $ns Int the namespace of the article
 257          * @param $title String the unprefixed database key form
 258          * @param $fragment String the link fragment (after the "#")
 259          * @param $interwiki String the interwiki prefix
 260          * @return Title the new object
 261          */
 262         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 263                 $t = new Title();
 264                 $t->mInterwiki = $interwiki;
 265                 $t->mFragment = $fragment;
 266                 $t->mNamespace = $ns = intval( $ns );
 267                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 268                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 269                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 270                 $t->mTextform = str_replace( '_', ' ', $title );
 271                 return $t;
 272         }
 273
 274         /**
 275          * Create a new Title from a namespace index and a DB key.
 276          * The parameters will be checked for validity, which is a bit slower
 277          * than makeTitle() but safer for user-provided data.
 278          *
 279          * @param $ns Int the namespace of the article
 280          * @param $title String database key form
 281          * @param $fragment String the link fragment (after the "#")
 282          * @param $interwiki String interwiki prefix
 283          * @return Title the new object, or NULL on an error
 284          */
 285         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 286                 $t = new Title();
 287                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 288                 if ( $t->secureAndSplit() ) {
 289                         return $t;
 290                 } else {
 291                         return null;
 292                 }
 293         }
 294
 295         /**
 296          * Create a new Title for the Main Page
 297          *
 298          * @return Title the new object
 299          */
 300         public static function newMainPage() {
 301                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 302                 // Don't give fatal errors if the message is broken
 303                 if ( !$title ) {
 304                         $title = Title::newFromText( 'Main Page' );
 305                 }
 306                 return $title;
 307         }
 308
 309         /**
 310          * Extract a redirect destination from a string and return the
 311          * Title, or null if the text doesn't contain a valid redirect
 312          * This will only return the very next target, useful for
 313          * the redirect table and other checks that don't need full recursion
 314          *
 315          * @param $text String: Text with possible redirect
 316          * @return Title: The corresponding Title
 317          */
 318         public static function newFromRedirect( $text ) {
 319                 return self::newFromRedirectInternal( $text );
 320         }
 321
 322         /**
 323          * Extract a redirect destination from a string and return the
 324          * Title, or null if the text doesn't contain a valid redirect
 325          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 326          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 327          *
 328          * @param $text String Text with possible redirect
 329          * @return Title
 330          */
 331         public static function newFromRedirectRecurse( $text ) {
 332                 $titles = self::newFromRedirectArray( $text );
 333                 return $titles ? array_pop( $titles ) : null;
 334         }
 335
 336         /**
 337          * Extract a redirect destination from a string and return an
 338          * array of Titles, or null if the text doesn't contain a valid redirect
 339          * The last element in the array is the final destination after all redirects
 340          * have been resolved (up to $wgMaxRedirects times)
 341          *
 342          * @param $text String Text with possible redirect
 343          * @return Array of Titles, with the destination last
 344          */
 345         public static function newFromRedirectArray( $text ) {
 346                 global $wgMaxRedirects;
 347                 $title = self::newFromRedirectInternal( $text );
 348                 if ( is_null( $title ) ) {
 349                         return null;
 350                 }
 351                 // recursive check to follow double redirects
 352                 $recurse = $wgMaxRedirects;
 353                 $titles = array( $title );
 354                 while ( --$recurse > 0 ) {
 355                         if ( $title->isRedirect() ) {
 356                                 $article = new Article( $title, 0 );
 357                                 $newtitle = $article->getRedirectTarget();
 358                         } else {
 359                                 break;
 360                         }
 361                         // Redirects to some special pages are not permitted
 362                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 363                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 364                                 $title = $newtitle;
 365                                 $titles[] = $newtitle;
 366                         } else {
 367                                 break;
 368                         }
 369                 }
 370                 return $titles;
 371         }
 372
 373         /**
 374          * Really extract the redirect destination
 375          * Do not call this function directly, use one of the newFromRedirect* functions above
 376          *
 377          * @param $text String Text with possible redirect
 378          * @return Title
 379          */
 380         protected static function newFromRedirectInternal( $text ) {
 381                 global $wgMaxRedirects;
 382                 if ( $wgMaxRedirects < 1 ) {
 383                         //redirects are disabled, so quit early
 384                         return null;
 385                 }
 386                 $redir = MagicWord::get( 'redirect' );
 387                 $text = trim( $text );
 388                 if ( $redir->matchStartAndRemove( $text ) ) {
 389                         // Extract the first link and see if it's usable
 390                         // Ensure that it really does come directly after #REDIRECT
 391                         // Some older redirects included a colon, so don't freak about that!
 392                         $m = array();
 393                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 394                                 // Strip preceding colon used to "escape" categories, etc.
 395                                 // and URL-decode links
 396                                 if ( strpos( $m[1], '%' ) !== false ) {
 397                                         // Match behavior of inline link parsing here;
 398                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 399                                 }
 400                                 $title = Title::newFromText( $m[1] );
 401                                 // If the title is a redirect to bad special pages or is invalid, return null
 402                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 403                                         return null;
 404                                 }
 405                                 return $title;
 406                         }
 407                 }
 408                 return null;
 409         }
 410
 411 # ----------------------------------------------------------------------------
 412 #       Static functions
 413 # ----------------------------------------------------------------------------
 414
 415         /**
 416          * Get the prefixed DB key associated with an ID
 417          *
 418          * @param $id Int the page_id of the article
 419          * @return Title an object representing the article, or NULL if no such article was found
 420          */
 421         public static function nameOf( $id ) {
 422                 $dbr = wfGetDB( DB_SLAVE );
 423
 424                 $s = $dbr->selectRow(
 425                         'page',
 426                         array( 'page_namespace', 'page_title' ),
 427                         array( 'page_id' => $id ),
 428                         __METHOD__
 429                 );
 430                 if ( $s === false ) {
 431                         return null;
 432                 }
 433
 434                 $n = self::makeName( $s->page_namespace, $s->page_title );
 435                 return $n;
 436         }
 437
 438         /**
 439          * Get a regex character class describing the legal characters in a link
 440          *
 441          * @return String the list of characters, not delimited
 442          */
 443         public static function legalChars() {
 444                 global $wgLegalTitleChars;
 445                 return $wgLegalTitleChars;
 446         }
 447
 448         /**
 449          * Get a string representation of a title suitable for
 450          * including in a search index
 451          *
 452          * @param $ns Int a namespace index
 453          * @param $title String text-form main part
 454          * @return String a stripped-down title string ready for the search index
 455          */
 456         public static function indexTitle( $ns, $title ) {
 457                 global $wgContLang;
 458
 459                 $lc = SearchEngine::legalSearchChars() . '&#;';
 460                 $t = $wgContLang->normalizeForSearch( $title );
 461                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 462                 $t = $wgContLang->lc( $t );
 463
 464                 # Handle 's, s'
 465                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 466                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 467
 468                 $t = preg_replace( "/\\s+/", ' ', $t );
 469
 470                 if ( $ns == NS_FILE ) {
 471                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 472                 }
 473                 return trim( $t );
 474         }
 475
 476         /**
 477          * Make a prefixed DB key from a DB key and a namespace index
 478          *
 479          * @param $ns Int numerical representation of the namespace
 480          * @param $title String the DB key form the title
 481          * @param $fragment String The link fragment (after the "#")
 482          * @param $interwiki String The interwiki prefix
 483          * @return String the prefixed form of the title
 484          */
 485         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 486                 global $wgContLang;
 487
 488                 $namespace = $wgContLang->getNsText( $ns );
 489                 $name = $namespace == '' ? $title : "$namespace:$title";
 490                 if ( strval( $interwiki ) != '' ) {
 491                         $name = "$interwiki:$name";
 492                 }
 493                 if ( strval( $fragment ) != '' ) {
 494                         $name .= '#' . $fragment;
 495                 }
 496                 return $name;
 497         }
 498
 499         /**
 500          * Determine whether the object refers to a page within
 501          * this project.
 502          *
 503          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 504          */
 505         public function isLocal() {
 506                 if ( $this->mInterwiki != '' ) {
 507                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 508                 } else {
 509                         return true;
 510                 }
 511         }
 512
 513         /**
 514          * Determine whether the object refers to a page within
 515          * this project and is transcludable.
 516          *
 517          * @return Bool TRUE if this is transcludable
 518          */
 519         public function isTrans() {
 520                 if ( $this->mInterwiki == '' ) {
 521                         return false;
 522                 }
 523
 524                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 525         }
 526
 527         /**
 528          * Returns the DB name of the distant wiki which owns the object.
 529          *
 530          * @return String the DB name
 531          */
 532         public function getTransWikiID() {
 533                 if ( $this->mInterwiki == '' ) {
 534                         return false;
 535                 }
 536
 537                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 538         }
 539
 540         /**
 541          * Escape a text fragment, say from a link, for a URL
 542          *
 543          * @param $fragment string containing a URL or link fragment (after the "#")
 544          * @return String: escaped string
 545          */
 546         static function escapeFragmentForURL( $fragment ) {
 547                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 548                 # fragments appear not to work in IE (at least up to 7) or in at least
 549                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 550                 # to care if they aren't encoded.
 551                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 552         }
 553
 554 # ----------------------------------------------------------------------------
 555 #       Other stuff
 556 # ----------------------------------------------------------------------------
 557
 558         /** Simple accessors */
 559         /**
 560          * Get the text form (spaces not underscores) of the main part
 561          *
 562          * @return String Main part of the title
 563          */
 564         public function getText() { return $this->mTextform; }
 565
 566         /**
 567          * Get the URL-encoded form of the main part
 568          *
 569          * @return String Main part of the title, URL-encoded
 570          */
 571         public function getPartialURL() { return $this->mUrlform; }
 572
 573         /**
 574          * Get the main part with underscores
 575          *
 576          * @return String: Main part of the title, with underscores
 577          */
 578         public function getDBkey() { return $this->mDbkeyform; }
 579
 580         /**
 581          * Get the namespace index, i.e. one of the NS_xxxx constants.
 582          *
 583          * @return Integer: Namespace index
 584          */
 585         public function getNamespace() { return $this->mNamespace; }
 586
 587         /**
 588          * Get the namespace text
 589          *
 590          * @return String: Namespace text
 591          */
 592         public function getNsText() {
 593                 global $wgContLang;
 594
 595                 if ( $this->mInterwiki != '' ) {
 596                         // This probably shouldn't even happen. ohh man, oh yuck.
 597                         // But for interwiki transclusion it sometimes does.
 598                         // Shit. Shit shit shit.
 599                         //
 600                         // Use the canonical namespaces if possible to try to
 601                         // resolve a foreign namespace.
 602                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 603                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 604                         }
 605                 }
 606
 607                 if ( $wgContLang->needsGenderDistinction() &&
 608                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 609                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 610                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 611                 }
 612
 613                 return $wgContLang->getNsText( $this->mNamespace );
 614         }
 615
 616         /**
 617          * Get the DB key with the initial letter case as specified by the user
 618          *
 619          * @return String DB key
 620          */
 621         function getUserCaseDBKey() {
 622                 return $this->mUserCaseDBKey;
 623         }
 624
 625         /**
 626          * Get the namespace text of the subject (rather than talk) page
 627          *
 628          * @return String Namespace text
 629          */
 630         public function getSubjectNsText() {
 631                 global $wgContLang;
 632                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 633         }
 634
 635         /**
 636          * Get the namespace text of the talk page
 637          *
 638          * @return String Namespace text
 639          */
 640         public function getTalkNsText() {
 641                 global $wgContLang;
 642                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 643         }
 644
 645         /**
 646          * Could this title have a corresponding talk page?
 647          *
 648          * @return Bool TRUE or FALSE
 649          */
 650         public function canTalk() {
 651                 return( MWNamespace::canTalk( $this->mNamespace ) );
 652         }
 653
 654         /**
 655          * Get the interwiki prefix (or null string)
 656          *
 657          * @return String Interwiki prefix
 658          */
 659         public function getInterwiki() { return $this->mInterwiki; }
 660
 661         /**
 662          * Get the Title fragment (i.e.\ the bit after the #) in text form
 663          *
 664          * @return String Title fragment
 665          */
 666         public function getFragment() { return $this->mFragment; }
 667
 668         /**
 669          * Get the fragment in URL form, including the "#" character if there is one
 670          * @return String Fragment in URL form
 671          */
 672         public function getFragmentForURL() {
 673                 if ( $this->mFragment == '' ) {
 674                         return '';
 675                 } else {
 676                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 677                 }
 678         }
 679
 680         /**
 681          * Get the default namespace index, for when there is no namespace
 682          *
 683          * @return Int Default namespace index
 684          */
 685         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 686
 687         /**
 688          * Get title for search index
 689          *
 690          * @return String a stripped-down title string ready for the
 691          *  search index
 692          */
 693         public function getIndexTitle() {
 694                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 695         }
 696
 697         /**
 698          * Get the prefixed database key form
 699          *
 700          * @return String the prefixed title, with underscores and
 701          *  any interwiki and namespace prefixes
 702          */
 703         public function getPrefixedDBkey() {
 704                 $s = $this->prefix( $this->mDbkeyform );
 705                 $s = str_replace( ' ', '_', $s );
 706                 return $s;
 707         }
 708
 709         /**
 710          * Get the prefixed title with spaces.
 711          * This is the form usually used for display
 712          *
 713          * @return String the prefixed title, with spaces
 714          */
 715         public function getPrefixedText() {
 716                 // @todo FIXME: Bad usage of empty() ?
 717                 if ( empty( $this->mPrefixedText ) ) {
 718                         $s = $this->prefix( $this->mTextform );
 719                         $s = str_replace( '_', ' ', $s );
 720                         $this->mPrefixedText = $s;
 721                 }
 722                 return $this->mPrefixedText;
 723         }
 724
 725         /**
 726          * Get the prefixed title with spaces, plus any fragment
 727          * (part beginning with '#')
 728          *
 729          * @return String the prefixed title, with spaces and the fragment, including '#'
 730          */
 731         public function getFullText() {
 732                 $text = $this->getPrefixedText();
 733                 if ( $this->mFragment != '' ) {
 734                         $text .= '#' . $this->mFragment;
 735                 }
 736                 return $text;
 737         }
 738
 739         /**
 740          * Get the base name, i.e. the leftmost parts before the /
 741          *
 742          * @return String Base name
 743          */
 744         public function getBaseText() {
 745                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 746                         return $this->getText();
 747                 }
 748
 749                 $parts = explode( '/', $this->getText() );
 750                 # Don't discard the real title if there's no subpage involved
 751                 if ( count( $parts ) > 1 ) {
 752                         unset( $parts[count( $parts ) - 1] );
 753                 }
 754                 return implode( '/', $parts );
 755         }
 756
 757         /**
 758          * Get the lowest-level subpage name, i.e. the rightmost part after /
 759          *
 760          * @return String Subpage name
 761          */
 762         public function getSubpageText() {
 763                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 764                         return( $this->mTextform );
 765                 }
 766                 $parts = explode( '/', $this->mTextform );
 767                 return( $parts[count( $parts ) - 1] );
 768         }
 769
 770         /**
 771          * Get a URL-encoded form of the subpage text
 772          *
 773          * @return String URL-encoded subpage name
 774          */
 775         public function getSubpageUrlForm() {
 776                 $text = $this->getSubpageText();
 777                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 778                 return( $text );
 779         }
 780
 781         /**
 782          * Get a URL-encoded title (not an actual URL) including interwiki
 783          *
 784          * @return String the URL-encoded form
 785          */
 786         public function getPrefixedURL() {
 787                 $s = $this->prefix( $this->mDbkeyform );
 788                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 789                 return $s;
 790         }
 791
 792         /**
 793          * Get a real URL referring to this title, with interwiki link and
 794          * fragment
 795          *
 796          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 797          *   links. Can be specified as an associative array as well, e.g.,
 798          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 799          * @param $variant String language variant of url (for sr, zh..)
 800          * @return String the URL
 801          */
 802         public function getFullURL( $query = '', $variant = false ) {
 803                 global $wgServer, $wgRequest;
 804
 805                 if ( is_array( $query ) ) {
 806                         $query = wfArrayToCGI( $query );
 807                 }
 808
 809                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 810                 if ( !$interwiki ) {
 811                         $url = $this->getLocalURL( $query, $variant );
 812
 813                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 814                         // Correct fix would be to move the prepending elsewhere.
 815                         if ( $wgRequest->getVal( 'action' ) != 'render' ) {
 816                                 $url = $wgServer . $url;
 817                         }
 818                 } else {
 819                         $baseUrl = $interwiki->getURL();
 820
 821                         $namespace = wfUrlencode( $this->getNsText() );
 822                         if ( $namespace != '' ) {
 823                                 # Can this actually happen? Interwikis shouldn't be parsed.
 824                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 825                                 $namespace .= ':';
 826                         }
 827                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 828                         $url = wfAppendQuery( $url, $query );
 829                 }
 830
 831                 # Finally, add the fragment.
 832                 $url .= $this->getFragmentForURL();
 833
 834                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 835                 return $url;
 836         }
 837
 838         /**
 839          * Get a URL with no fragment or server name.  If this page is generated
 840          * with action=render, $wgServer is prepended.
 841          *
 842          * @param $query Mixed: an optional query string; if not specified,
 843          *   $wgArticlePath will be used.  Can be specified as an associative array
 844          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 845          *   URL-escaped).
 846          * @param $variant String language variant of url (for sr, zh..)
 847          * @return String the URL
 848          */
 849         public function getLocalURL( $query = '', $variant = false ) {
 850                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 851                 global $wgVariantArticlePath, $wgContLang;
 852
 853                 if ( is_array( $query ) ) {
 854                         $query = wfArrayToCGI( $query );
 855                 }
 856
 857                 if ( $this->isExternal() ) {
 858                         $url = $this->getFullURL();
 859                         if ( $query ) {
 860                                 // This is currently only used for edit section links in the
 861                                 // context of interwiki transclusion. In theory we should
 862                                 // append the query to the end of any existing query string,
 863                                 // but interwiki transclusion is already broken in that case.
 864                                 $url .= "?$query";
 865                         }
 866                 } else {
 867                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 868                         if ( $query == '' ) {
 869                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 870                                         if ( !$wgVariantArticlePath ) {
 871                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 872                                         } else {
 873                                                 $variantArticlePath = $wgVariantArticlePath;
 874                                         }
 875                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 876                                         $url = str_replace( '$1', $dbkey, $url  );
 877                                 } else {
 878                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 879                                 }
 880                         } else {
 881                                 global $wgActionPaths;
 882                                 $url = false;
 883                                 $matches = array();
 884                                 if ( !empty( $wgActionPaths ) &&
 885                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 886                                 {
 887                                         $action = urldecode( $matches[2] );
 888                                         if ( isset( $wgActionPaths[$action] ) ) {
 889                                                 $query = $matches[1];
 890                                                 if ( isset( $matches[4] ) ) {
 891                                                         $query .= $matches[4];
 892                                                 }
 893                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 894                                                 if ( $query != '' ) {
 895                                                         $url = wfAppendQuery( $url, $query );
 896                                                 }
 897                                         }
 898                                 }
 899
 900                                 if ( $url === false ) {
 901                                         if ( $query == '-' ) {
 902                                                 $query = '';
 903                                         }
 904                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 905                                 }
 906                         }
 907
 908                         // @todo FIXME: This causes breakage in various places when we
 909                         // actually expected a local URL and end up with dupe prefixes.
 910                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 911                                 $url = $wgServer . $url;
 912                         }
 913                 }
 914                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 915                 return $url;
 916         }
 917
 918         /**
 919          * Get a URL that's the simplest URL that will be valid to link, locally,
 920          * to the current Title.  It includes the fragment, but does not include
 921          * the server unless action=render is used (or the link is external).  If
 922          * there's a fragment but the prefixed text is empty, we just return a link
 923          * to the fragment.
 924          *
 925          * The result obviously should not be URL-escaped, but does need to be
 926          * HTML-escaped if it's being output in HTML.
 927          *
 928          * @param $query Array of Strings An associative array of key => value pairs for the
 929          *   query string.  Keys and values will be escaped.
 930          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 931          *   for external links.  Default is "false" (same variant as current page,
 932          *   for anonymous users).
 933          * @return String the URL
 934          */
 935         public function getLinkUrl( $query = array(), $variant = false ) {
 936                 wfProfileIn( __METHOD__ );
 937                 if ( $this->isExternal() ) {
 938                         $ret = $this->getFullURL( $query );
 939                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 940                         $ret = $this->getFragmentForURL();
 941                 } else {
 942                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 943                 }
 944                 wfProfileOut( __METHOD__ );
 945                 return $ret;
 946         }
 947
 948         /**
 949          * Get an HTML-escaped version of the URL form, suitable for
 950          * using in a link, without a server name or fragment
 951          *
 952          * @param $query String an optional query string
 953          * @return String the URL
 954          */
 955         public function escapeLocalURL( $query = '' ) {
 956                 return htmlspecialchars( $this->getLocalURL( $query ) );
 957         }
 958
 959         /**
 960          * Get an HTML-escaped version of the URL form, suitable for
 961          * using in a link, including the server name and fragment
 962          *
 963          * @param $query String an optional query string
 964          * @return String the URL
 965          */
 966         public function escapeFullURL( $query = '' ) {
 967                 return htmlspecialchars( $this->getFullURL( $query ) );
 968         }
 969
 970         /**
 971          * Get the URL form for an internal link.
 972          * - Used in various Squid-related code, in case we have a different
 973          * internal hostname for the server from the exposed one.
 974          *
 975          * @param $query String an optional query string
 976          * @param $variant String language variant of url (for sr, zh..)
 977          * @return String the URL
 978          */
 979         public function getInternalURL( $query = '', $variant = false ) {
 980                 global $wgInternalServer, $wgServer;
 981                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
 982                 $url = $server . $this->getLocalURL( $query, $variant );
 983                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
 984                 return $url;
 985         }
 986
 987         /**
 988          * Get the edit URL for this Title
 989          *
 990          * @return String the URL, or a null string if this is an
 991          *  interwiki link
 992          */
 993         public function getEditURL() {
 994                 if ( $this->mInterwiki != '' ) {
 995                         return '';
 996                 }
 997                 $s = $this->getLocalURL( 'action=edit' );
 998
 999                 return $s;
1000         }
1001
1002         /**
1003          * Get the HTML-escaped displayable text form.
1004          * Used for the title field in <a> tags.
1005          *
1006          * @return String the text, including any prefixes
1007          */
1008         public function getEscapedText() {
1009                 return htmlspecialchars( $this->getPrefixedText() );
1010         }
1011
1012         /**
1013          * Is this Title interwiki?
1014          *
1015          * @return Bool
1016          */
1017         public function isExternal() {
1018                 return ( $this->mInterwiki != '' );
1019         }
1020
1021         /**
1022          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1023          *
1024          * @param $action String Action to check (default: edit)
1025          * @return Bool
1026          */
1027         public function isSemiProtected( $action = 'edit' ) {
1028                 if ( $this->exists() ) {
1029                         $restrictions = $this->getRestrictions( $action );
1030                         if ( count( $restrictions ) > 0 ) {
1031                                 foreach ( $restrictions as $restriction ) {
1032                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1033                                                 return false;
1034                                         }
1035                                 }
1036                         } else {
1037                                 # Not protected
1038                                 return false;
1039                         }
1040                         return true;
1041                 } else {
1042                         # If it doesn't exist, it can't be protected
1043                         return false;
1044                 }
1045         }
1046
1047         /**
1048          * Does the title correspond to a protected article?
1049          *
1050          * @param $action String the action the page is protected from,
1051          * by default checks all actions.
1052          * @return Bool
1053          */
1054         public function isProtected( $action = '' ) {
1055                 global $wgRestrictionLevels;
1056
1057                 $restrictionTypes = $this->getRestrictionTypes();
1058
1059                 # Special pages have inherent protection
1060                 if( $this->getNamespace() == NS_SPECIAL ) {
1061                         return true;
1062                 }
1063
1064                 # Check regular protection levels
1065                 foreach ( $restrictionTypes as $type ) {
1066                         if ( $action == $type || $action == '' ) {
1067                                 $r = $this->getRestrictions( $type );
1068                                 foreach ( $wgRestrictionLevels as $level ) {
1069                                         if ( in_array( $level, $r ) && $level != '' ) {
1070                                                 return true;
1071                                         }
1072                                 }
1073                         }
1074                 }
1075
1076                 return false;
1077         }
1078
1079         /**
1080          * Is this a conversion table for the LanguageConverter?
1081          *
1082          * @return Bool
1083          */
1084         public function isConversionTable() {
1085                 if(
1086                         $this->getNamespace() == NS_MEDIAWIKI &&
1087                         strpos( $this->getText(), 'Conversiontable' ) !== false
1088                 )
1089                 {
1090                         return true;
1091                 }
1092
1093                 return false;
1094         }
1095
1096         /**
1097          * Is $wgUser watching this page?
1098          *
1099          * @return Bool
1100          */
1101         public function userIsWatching() {
1102                 global $wgUser;
1103
1104                 if ( is_null( $this->mWatched ) ) {
1105                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1106                                 $this->mWatched = false;
1107                         } else {
1108                                 $this->mWatched = $wgUser->isWatched( $this );
1109                         }
1110                 }
1111                 return $this->mWatched;
1112         }
1113
1114         /**
1115          * Can $wgUser perform $action on this page?
1116          * This skips potentially expensive cascading permission checks
1117          * as well as avoids expensive error formatting
1118          *
1119          * Suitable for use for nonessential UI controls in common cases, but
1120          * _not_ for functional access control.
1121          *
1122          * May provide false positives, but should never provide a false negative.
1123          *
1124          * @param $action String action that permission needs to be checked for
1125          * @return Bool
1126          */
1127         public function quickUserCan( $action ) {
1128                 return $this->userCan( $action, false );
1129         }
1130
1131         /**
1132          * Determines if $user is unable to edit this page because it has been protected
1133          * by $wgNamespaceProtection.
1134          *
1135          * @param $user User object, $wgUser will be used if not passed
1136          * @return Bool
1137          */
1138         public function isNamespaceProtected( User $user = null ) {
1139                 global $wgNamespaceProtection;
1140
1141                 if ( $user === null ) {
1142                         global $wgUser;
1143                         $user = $wgUser;
1144                 }
1145
1146                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1147                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1148                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1149                                         return true;
1150                                 }
1151                         }
1152                 }
1153                 return false;
1154         }
1155
1156         /**
1157          * Can $wgUser perform $action on this page?
1158          *
1159          * @param $action String action that permission needs to be checked for
1160          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1161          * @return Bool
1162          */
1163         public function userCan( $action, $doExpensiveQueries = true ) {
1164                 global $wgUser;
1165                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1166         }
1167
1168         /**
1169          * Can $user perform $action on this page?
1170          *
1171          * @todo FIXME: This *does not* check throttles (User::pingLimiter()).
1172          *
1173          * @param $action String action that permission needs to be checked for
1174          * @param $user User to check
1175          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries by
1176          *   skipping checks for cascading protections and user blocks.
1177          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1178          * @return Array of arguments to wfMsg to explain permissions problems.
1179          */
1180         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1181                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1182
1183                 // Remove the errors being ignored.
1184                 foreach ( $errors as $index => $error ) {
1185                         $error_key = is_array( $error ) ? $error[0] : $error;
1186
1187                         if ( in_array( $error_key, $ignoreErrors ) ) {
1188                                 unset( $errors[$index] );
1189                         }
1190                 }
1191
1192                 return $errors;
1193         }
1194
1195         /**
1196          * Permissions checks that fail most often, and which are easiest to test.
1197          *
1198          * @param $action String the action to check
1199          * @param $user User user to check
1200          * @param $errors Array list of current errors
1201          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1202          * @param $short Boolean short circuit on first error
1203          *
1204          * @return Array list of errors
1205          */
1206         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1207                 if ( $action == 'create' ) {
1208                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1209                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1210                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1211                         }
1212                 } elseif ( $action == 'move' ) {
1213                         if ( !$user->isAllowed( 'move-rootuserpages' )
1214                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1215                                 // Show user page-specific message only if the user can move other pages
1216                                 $errors[] = array( 'cant-move-user-page' );
1217                         }
1218
1219                         // Check if user is allowed to move files if it's a file
1220                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1221                                 $errors[] = array( 'movenotallowedfile' );
1222                         }
1223
1224                         if ( !$user->isAllowed( 'move' ) ) {
1225                                 // User can't move anything
1226                                 global $wgGroupPermissions;
1227                                 $userCanMove = false;
1228                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1229                                         $userCanMove = $wgGroupPermissions['user']['move'];
1230                                 }
1231                                 $autoconfirmedCanMove = false;
1232                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1233                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1234                                 }
1235                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1236                                         // custom message if logged-in users without any special rights can move
1237                                         $errors[] = array( 'movenologintext' );
1238                                 } else {
1239                                         $errors[] = array( 'movenotallowed' );
1240                                 }
1241                         }
1242                 } elseif ( $action == 'move-target' ) {
1243                         if ( !$user->isAllowed( 'move' ) ) {
1244                                 // User can't move anything
1245                                 $errors[] = array( 'movenotallowed' );
1246                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1247                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1248                                 // Show user page-specific message only if the user can move other pages
1249                                 $errors[] = array( 'cant-move-to-user-page' );
1250                         }
1251                 } elseif ( !$user->isAllowed( $action ) ) {
1252                         // We avoid expensive display logic for quickUserCan's and such
1253                         $groups = false;
1254                         if ( !$short ) {
1255                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1256                                         User::getGroupsWithPermission( $action ) );
1257                         }
1258
1259                         if ( $groups ) {
1260                                 global $wgLang;
1261                                 $return = array(
1262                                         'badaccess-groups',
1263                                         $wgLang->commaList( $groups ),
1264                                         count( $groups )
1265                                 );
1266                         } else {
1267                                 $return = array( 'badaccess-group0' );
1268                         }
1269                         $errors[] = $return;
1270                 }
1271
1272                 return $errors;
1273         }
1274
1275         /**
1276          * Add the resulting error code to the errors array
1277          *
1278          * @param $errors Array list of current errors
1279          * @param $result Mixed result of errors
1280          *
1281          * @return Array list of errors
1282          */
1283         private function resultToError( $errors, $result ) {
1284                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1285                         // A single array representing an error
1286                         $errors[] = $result;
1287                 } elseif ( is_array( $result ) && is_array( $result[0] ) ) {
1288                         // A nested array representing multiple errors
1289                         $errors = array_merge( $errors, $result );
1290                 } elseif ( $result !== '' && is_string( $result ) ) {
1291                         // A string representing a message-id
1292                         $errors[] = array( $result );
1293                 } elseif ( $result === false ) {
1294                         // a generic "We don't want them to do that"
1295                         $errors[] = array( 'badaccess-group0' );
1296                 }
1297                 return $errors;
1298         }
1299
1300         /**
1301          * Check various permission hooks
1302          *
1303          * @param $action String the action to check
1304          * @param $user User user to check
1305          * @param $errors Array list of current errors
1306          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1307          * @param $short Boolean short circuit on first error
1308          *
1309          * @return Array list of errors
1310          */
1311         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1312                 // Use getUserPermissionsErrors instead
1313                 $result = '';
1314                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1315                         return $result ? array() : array( array( 'badaccess-group0' ) );
1316                 }
1317                 // Check getUserPermissionsErrors hook
1318                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1319                         $errors = $this->resultToError( $errors, $result );
1320                 }
1321                 // Check getUserPermissionsErrorsExpensive hook
1322                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1323                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1324                         $errors = $this->resultToError( $errors, $result );
1325                 }
1326
1327                 return $errors;
1328         }
1329
1330         /**
1331          * Check permissions on special pages & namespaces
1332          *
1333          * @param $action String the action to check
1334          * @param $user User user to check
1335          * @param $errors Array list of current errors
1336          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1337          * @param $short Boolean short circuit on first error
1338          *
1339          * @return Array list of errors
1340          */
1341         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1342                 # Only 'createaccount' and 'execute' can be performed on
1343                 # special pages, which don't actually exist in the DB.
1344                 $specialOKActions = array( 'createaccount', 'execute' );
1345                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1346                         $errors[] = array( 'ns-specialprotected' );
1347                 }
1348
1349                 # Check $wgNamespaceProtection for restricted namespaces
1350                 if ( $this->isNamespaceProtected( $user ) ) {
1351                         $ns = $this->mNamespace == NS_MAIN ?
1352                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1353                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1354                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1355                 }
1356
1357                 return $errors;
1358         }
1359
1360         /**
1361          * Check CSS/JS sub-page permissions
1362          *
1363          * @param $action String the action to check
1364          * @param $user User user to check
1365          * @param $errors Array list of current errors
1366          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1367          * @param $short Boolean short circuit on first error
1368          *
1369          * @return Array list of errors
1370          */
1371         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1372                 # Protect css/js subpages of user pages
1373                 # XXX: this might be better using restrictions
1374                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssSubpage()
1375                 #      and $this->userCanEditJsSubpage() from working
1376                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1377                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1378                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1379                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1380                                 $errors[] = array( 'customcssprotected' );
1381                         } elseif ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1382                                 $errors[] = array( 'customjsprotected' );
1383                         }
1384                 }
1385
1386                 return $errors;
1387         }
1388
1389         /**
1390          * Check against page_restrictions table requirements on this
1391          * page. The user must possess all required rights for this
1392          * action.
1393          *
1394          * @param $action String the action to check
1395          * @param $user User user to check
1396          * @param $errors Array list of current errors
1397          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1398          * @param $short Boolean short circuit on first error
1399          *
1400          * @return Array list of errors
1401          */
1402         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1403                 foreach ( $this->getRestrictions( $action ) as $right ) {
1404                         // Backwards compatibility, rewrite sysop -> protect
1405                         if ( $right == 'sysop' ) {
1406                                 $right = 'protect';
1407                         }
1408                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1409                                 // Users with 'editprotected' permission can edit protected pages
1410                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected' ) ) {
1411                                         // Users with 'editprotected' permission cannot edit protected pages
1412                                         // with cascading option turned on.
1413                                         if ( $this->mCascadeRestriction ) {
1414                                                 $errors[] = array( 'protectedpagetext', $right );
1415                                         }
1416                                 } else {
1417                                         $errors[] = array( 'protectedpagetext', $right );
1418                                 }
1419                         }
1420                 }
1421
1422                 return $errors;
1423         }
1424
1425         /**
1426          * Check restrictions on cascading pages.
1427          *
1428          * @param $action String the action to check
1429          * @param $user User to check
1430          * @param $errors Array list of current errors
1431          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1432          * @param $short Boolean short circuit on first error
1433          *
1434          * @return Array list of errors
1435          */
1436         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1437                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1438                         # We /could/ use the protection level on the source page, but it's
1439                         # fairly ugly as we have to establish a precedence hierarchy for pages
1440                         # included by multiple cascade-protected pages. So just restrict
1441                         # it to people with 'protect' permission, as they could remove the
1442                         # protection anyway.
1443                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1444                         # Cascading protection depends on more than this page...
1445                         # Several cascading protected pages may include this page...
1446                         # Check each cascading level
1447                         # This is only for protection restrictions, not for all actions
1448                         if ( isset( $restrictions[$action] ) ) {
1449                                 foreach ( $restrictions[$action] as $right ) {
1450                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1451                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1452                                                 $pages = '';
1453                                                 foreach ( $cascadingSources as $page )
1454                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1455                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1456                                         }
1457                                 }
1458                         }
1459                 }
1460
1461                 return $errors;
1462         }
1463
1464         /**
1465          * Check action permissions not already checked in checkQuickPermissions
1466          *
1467          * @param $action String the action to check
1468          * @param $user User to check
1469          * @param $errors Array list of current errors
1470          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1471          * @param $short Boolean short circuit on first error
1472          *
1473          * @return Array list of errors
1474          */
1475         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1476                 if ( $action == 'protect' ) {
1477                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1478                                 // If they can't edit, they shouldn't protect.
1479                                 $errors[] = array( 'protect-cantedit' );
1480                         }
1481                 } elseif ( $action == 'create' ) {
1482                         $title_protection = $this->getTitleProtection();
1483                         if( $title_protection ) {
1484                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1485                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1486                                 }
1487                                 if( $title_protection['pt_create_perm'] == '' || !$user->isAllowed( $title_protection['pt_create_perm'] ) ) {
1488                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1489                                 }
1490                         }
1491                 } elseif ( $action == 'move' ) {
1492                         // Check for immobile pages
1493                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1494                                 // Specific message for this case
1495                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1496                         } elseif ( !$this->isMovable() ) {
1497                                 // Less specific message for rarer cases
1498                                 $errors[] = array( 'immobile-page' );
1499                         }
1500                 } elseif ( $action == 'move-target' ) {
1501                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1502                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1503                         } elseif ( !$this->isMovable() ) {
1504                                 $errors[] = array( 'immobile-target-page' );
1505                         }
1506                 }
1507                 return $errors;
1508         }
1509
1510         /**
1511          * Check that the user isn't blocked from editting.
1512          *
1513          * @param $action String the action to check
1514          * @param $user User to check
1515          * @param $errors Array list of current errors
1516          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1517          * @param $short Boolean short circuit on first error
1518          *
1519          * @return Array list of errors
1520          */
1521         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1522                 if( !$doExpensiveQueries ) {
1523                         return $errors;
1524                 }
1525
1526                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1527
1528                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1529                         $errors[] = array( 'confirmedittext' );
1530                 }
1531
1532                 if ( in_array( $action, array( 'read', 'createaccount', 'unblock' ) ) ){
1533                         // Edit blocks should not affect reading.
1534                         // Account creation blocks handled at userlogin.
1535                         // Unblocking handled in SpecialUnblock
1536                 } elseif( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ){
1537                         // Don't block the user from editing their own talk page unless they've been
1538                         // explicitly blocked from that too.
1539                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1540                         $block = $user->mBlock;
1541
1542                         // This is from OutputPage::blockedPage
1543                         // Copied at r23888 by werdna
1544
1545                         $id = $user->blockedBy();
1546                         $reason = $user->blockedFor();
1547                         if ( $reason == '' ) {
1548                                 $reason = wfMsg( 'blockednoreason' );
1549                         }
1550                         $ip = wfGetIP();
1551
1552                         if ( is_numeric( $id ) ) {
1553                                 $name = User::whoIs( $id );
1554                         } else {
1555                                 $name = $id;
1556                         }
1557
1558                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1559                         $blockid = $block->getId();
1560                         $blockExpiry = $user->mBlock->mExpiry;
1561                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1562                         if ( $blockExpiry == 'infinity' ) {
1563                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1564                         } else {
1565                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1566                         }
1567
1568                         $intended = strval( $user->mBlock->getTarget() );
1569
1570                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1571                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1572                 }
1573
1574                 return $errors;
1575         }
1576
1577         /**
1578          * Can $user perform $action on this page? This is an internal function,
1579          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1580          * checks on wfReadOnly() and blocks)
1581          *
1582          * @param $action String action that permission needs to be checked for
1583          * @param $user User to check
1584          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1585          * @param $short Bool Set this to true to stop after the first permission error.
1586          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1587          */
1588         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1589                 wfProfileIn( __METHOD__ );
1590
1591                 $errors = array();
1592                 $checks = array(
1593                         'checkQuickPermissions',
1594                         'checkPermissionHooks',
1595                         'checkSpecialsAndNSPermissions',
1596                         'checkCSSandJSPermissions',
1597                         'checkPageRestrictions',
1598                         'checkCascadingSourcesRestrictions',
1599                         'checkActionPermissions',
1600                         'checkUserBlock'
1601                 );
1602
1603                 while( count( $checks ) > 0 &&
1604                            !( $short && count( $errors ) > 0 ) ) {
1605                         $method = array_shift( $checks );
1606                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1607                 }
1608
1609                 wfProfileOut( __METHOD__ );
1610                 return $errors;
1611         }
1612
1613         /**
1614          * Is this title subject to title protection?
1615          * Title protection is the one applied against creation of such title.
1616          *
1617          * @return Mixed An associative array representing any existent title
1618          *   protection, or false if there's none.
1619          */
1620         private function getTitleProtection() {
1621                 // Can't protect pages in special namespaces
1622                 if ( $this->getNamespace() < 0 ) {
1623                         return false;
1624                 }
1625
1626                 // Can't protect pages that exist.
1627                 if ( $this->exists() ) {
1628                         return false;
1629                 }
1630
1631                 if ( !isset( $this->mTitleProtection ) ) {
1632                         $dbr = wfGetDB( DB_SLAVE );
1633                         $res = $dbr->select( 'protected_titles', '*',
1634                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1635                                 __METHOD__ );
1636
1637                         // fetchRow returns false if there are no rows.
1638                         $this->mTitleProtection = $dbr->fetchRow( $res );
1639                 }
1640                 return $this->mTitleProtection;
1641         }
1642
1643         /**
1644          * Update the title protection status
1645          *
1646          * @param $create_perm String Permission required for creation
1647          * @param $reason String Reason for protection
1648          * @param $expiry String Expiry timestamp
1649          * @return boolean true
1650          */
1651         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1652                 global $wgUser, $wgContLang;
1653
1654                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1655                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1656                         // No change
1657                         return true;
1658                 }
1659
1660                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1661
1662                 $dbw = wfGetDB( DB_MASTER );
1663
1664                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
1665
1666                 $expiry_description = '';
1667                 if ( $encodedExpiry != $dbw->getInfinity() ) {
1668                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1669                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1670                 } else {
1671                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1672                 }
1673
1674                 # Update protection table
1675                 if ( $create_perm != '' ) {
1676                         $this->mTitleProtection = array(
1677                                         'pt_namespace' => $namespace,
1678                                         'pt_title' => $title,
1679                                         'pt_create_perm' => $create_perm,
1680                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
1681                                         'pt_expiry' => $encodedExpiry,
1682                                         'pt_user' => $wgUser->getId(),
1683                                         'pt_reason' => $reason,
1684                                 );
1685                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1686                                 $this->mTitleProtection, __METHOD__     );
1687                 } else {
1688                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1689                                 'pt_title' => $title ), __METHOD__ );
1690                         $this->mTitleProtection = false;
1691                 }
1692
1693                 # Update the protection log
1694                 if ( $dbw->affectedRows() ) {
1695                         $log = new LogPage( 'protect' );
1696
1697                         if ( $create_perm ) {
1698                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1699                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1700                         } else {
1701                                 $log->addEntry( 'unprotect', $this, $reason );
1702                         }
1703                 }
1704
1705                 return true;
1706         }
1707
1708         /**
1709          * Remove any title protection due to page existing
1710          */
1711         public function deleteTitleProtection() {
1712                 $dbw = wfGetDB( DB_MASTER );
1713
1714                 $dbw->delete(
1715                         'protected_titles',
1716                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1717                         __METHOD__
1718                 );
1719                 $this->mTitleProtection = false;
1720         }
1721
1722         /**
1723          * Would anybody with sufficient privileges be able to move this page?
1724          * Some pages just aren't movable.
1725          *
1726          * @return Bool TRUE or FALSE
1727          */
1728         public function isMovable() {
1729                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1730         }
1731
1732         /**
1733          * Can $wgUser read this page?
1734          *
1735          * @return Bool
1736          * @todo fold these checks into userCan()
1737          */
1738         public function userCanRead() {
1739                 global $wgUser, $wgGroupPermissions;
1740
1741                 static $useShortcut = null;
1742
1743                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1744                 if ( is_null( $useShortcut ) ) {
1745                         global $wgRevokePermissions;
1746                         $useShortcut = true;
1747                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1748                                 # Not a public wiki, so no shortcut
1749                                 $useShortcut = false;
1750                         } elseif ( !empty( $wgRevokePermissions ) ) {
1751                                 /**
1752                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1753                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1754                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1755                                  * reading is allowed.
1756                                  */
1757                                 foreach ( $wgRevokePermissions as $perms ) {
1758                                         if ( !empty( $perms['read'] ) ) {
1759                                                 # We might be removing the read right from the user, so no shortcut
1760                                                 $useShortcut = false;
1761                                                 break;
1762                                         }
1763                                 }
1764                         }
1765                 }
1766
1767                 $result = null;
1768                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1769                 if ( $result !== null ) {
1770                         return $result;
1771                 }
1772
1773                 # Shortcut for public wikis, allows skipping quite a bit of code
1774                 if ( $useShortcut ) {
1775                         return true;
1776                 }
1777
1778                 if ( $wgUser->isAllowed( 'read' ) ) {
1779                         return true;
1780                 } else {
1781                         global $wgWhitelistRead;
1782
1783                         # Always grant access to the login page.
1784                         # Even anons need to be able to log in.
1785                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'ChangePassword' ) ) {
1786                                 return true;
1787                         }
1788
1789                         # Bail out if there isn't whitelist
1790                         if ( !is_array( $wgWhitelistRead ) ) {
1791                                 return false;
1792                         }
1793
1794                         # Check for explicit whitelisting
1795                         $name = $this->getPrefixedText();
1796                         $dbName = $this->getPrefixedDBKey();
1797                         // Check with and without underscores
1798                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1799                                 return true;
1800
1801                         # Old settings might have the title prefixed with
1802                         # a colon for main-namespace pages
1803                         if ( $this->getNamespace() == NS_MAIN ) {
1804                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1805                                         return true;
1806                                 }
1807                         }
1808
1809                         # If it's a special page, ditch the subpage bit and check again
1810                         if ( $this->getNamespace() == NS_SPECIAL ) {
1811                                 $name = $this->getDBkey();
1812                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
1813                                 if ( $name === false ) {
1814                                         # Invalid special page, but we show standard login required message
1815                                         return false;
1816                                 }
1817
1818                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1819                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1820                                         return true;
1821                                 }
1822                         }
1823
1824                 }
1825                 return false;
1826         }
1827
1828         /**
1829          * Is this the mainpage?
1830          * @note Title::newFromText seams to be sufficiently optimized by the title
1831          * cache that we don't need to over-optimize by doing direct comparisons and
1832          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1833          * ends up reporting something differently than $title->isMainPage();
1834          *
1835          * @return Bool
1836          */
1837         public function isMainPage() {
1838                 return $this->equals( Title::newMainPage() );
1839         }
1840
1841         /**
1842          * Is this a talk page of some sort?
1843          *
1844          * @return Bool
1845          */
1846         public function isTalkPage() {
1847                 return MWNamespace::isTalk( $this->getNamespace() );
1848         }
1849
1850         /**
1851          * Is this a subpage?
1852          *
1853          * @return Bool
1854          */
1855         public function isSubpage() {
1856                 return MWNamespace::hasSubpages( $this->mNamespace )
1857                         ? strpos( $this->getText(), '/' ) !== false
1858                         : false;
1859         }
1860
1861         /**
1862          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1863          *
1864          * @return Bool
1865          */
1866         public function hasSubpages() {
1867                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1868                         # Duh
1869                         return false;
1870                 }
1871
1872                 # We dynamically add a member variable for the purpose of this method
1873                 # alone to cache the result.  There's no point in having it hanging
1874                 # around uninitialized in every Title object; therefore we only add it
1875                 # if needed and don't declare it statically.
1876                 if ( isset( $this->mHasSubpages ) ) {
1877                         return $this->mHasSubpages;
1878                 }
1879
1880                 $subpages = $this->getSubpages( 1 );
1881                 if ( $subpages instanceof TitleArray ) {
1882                         return $this->mHasSubpages = (bool)$subpages->count();
1883                 }
1884                 return $this->mHasSubpages = false;
1885         }
1886
1887         /**
1888          * Get all subpages of this page.
1889          *
1890          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
1891          * @return mixed TitleArray, or empty array if this page's namespace
1892          *  doesn't allow subpages
1893          */
1894         public function getSubpages( $limit = -1 ) {
1895                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1896                         return array();
1897                 }
1898
1899                 $dbr = wfGetDB( DB_SLAVE );
1900                 $conds['page_namespace'] = $this->getNamespace();
1901                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1902                 $options = array();
1903                 if ( $limit > -1 ) {
1904                         $options['LIMIT'] = $limit;
1905                 }
1906                 return $this->mSubpages = TitleArray::newFromResult(
1907                         $dbr->select( 'page',
1908                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1909                                 $conds,
1910                                 __METHOD__,
1911                                 $options
1912                         )
1913                 );
1914         }
1915
1916         /**
1917          * Could this page contain custom CSS or JavaScript, based
1918          * on the title?
1919          *
1920          * @return Bool
1921          */
1922         public function isCssOrJsPage() {
1923                 return $this->mNamespace == NS_MEDIAWIKI
1924                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1925         }
1926
1927         /**
1928          * Is this a .css or .js subpage of a user page?
1929          * @return Bool
1930          */
1931         public function isCssJsSubpage() {
1932                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1933         }
1934
1935         /**
1936          * Is this a *valid* .css or .js subpage of a user page?
1937          *
1938          * @return Bool
1939          * @deprecated since 1.17
1940          */
1941         public function isValidCssJsSubpage() {
1942                 return $this->isCssJsSubpage();
1943         }
1944
1945         /**
1946          * Trim down a .css or .js subpage title to get the corresponding skin name
1947          *
1948          * @return string containing skin name from .css or .js subpage title
1949          */
1950         public function getSkinFromCssJsSubpage() {
1951                 $subpage = explode( '/', $this->mTextform );
1952                 $subpage = $subpage[ count( $subpage ) - 1 ];
1953                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1954         }
1955
1956         /**
1957          * Is this a .css subpage of a user page?
1958          *
1959          * @return Bool
1960          */
1961         public function isCssSubpage() {
1962                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1963         }
1964
1965         /**
1966          * Is this a .js subpage of a user page?
1967          *
1968          * @return Bool
1969          */
1970         public function isJsSubpage() {
1971                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1972         }
1973
1974         /**
1975          * Protect css subpages of user pages: can $wgUser edit
1976          * this page?
1977          *
1978          * @return Bool
1979          * @todo XXX: this might be better using restrictions
1980          */
1981         public function userCanEditCssSubpage() {
1982                 global $wgUser;
1983                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
1984                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1985         }
1986
1987         /**
1988          * Protect js subpages of user pages: can $wgUser edit
1989          * this page?
1990          *
1991          * @return Bool
1992          * @todo XXX: this might be better using restrictions
1993          */
1994         public function userCanEditJsSubpage() {
1995                 global $wgUser;
1996                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
1997                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1998         }
1999
2000         /**
2001          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2002          *
2003          * @return Bool If the page is subject to cascading restrictions.
2004          */
2005         public function isCascadeProtected() {
2006                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2007                 return ( $sources > 0 );
2008         }
2009
2010         /**
2011          * Cascading protection: Get the source of any cascading restrictions on this page.
2012          *
2013          * @param $getPages Bool Whether or not to retrieve the actual pages
2014          *        that the restrictions have come from.
2015          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2016          *     have come, false for none, or true if such restrictions exist, but $getPages
2017          *     was not set.  The restriction array is an array of each type, each of which
2018          *     contains a array of unique groups.
2019          */
2020         public function getCascadeProtectionSources( $getPages = true ) {
2021                 global $wgContLang;
2022                 $pagerestrictions = array();
2023
2024                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2025                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2026                 } elseif ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2027                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2028                 }
2029
2030                 wfProfileIn( __METHOD__ );
2031
2032                 $dbr = wfGetDB( DB_SLAVE );
2033
2034                 if ( $this->getNamespace() == NS_FILE ) {
2035                         $tables = array( 'imagelinks', 'page_restrictions' );
2036                         $where_clauses = array(
2037                                 'il_to' => $this->getDBkey(),
2038                                 'il_from=pr_page',
2039                                 'pr_cascade' => 1
2040                         );
2041                 } else {
2042                         $tables = array( 'templatelinks', 'page_restrictions' );
2043                         $where_clauses = array(
2044                                 'tl_namespace' => $this->getNamespace(),
2045                                 'tl_title' => $this->getDBkey(),
2046                                 'tl_from=pr_page',
2047                                 'pr_cascade' => 1
2048                         );
2049                 }
2050
2051                 if ( $getPages ) {
2052                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2053                                                    'pr_expiry', 'pr_type', 'pr_level' );
2054                         $where_clauses[] = 'page_id=pr_page';
2055                         $tables[] = 'page';
2056                 } else {
2057                         $cols = array( 'pr_expiry' );
2058                 }
2059
2060                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2061
2062                 $sources = $getPages ? array() : false;
2063                 $now = wfTimestampNow();
2064                 $purgeExpired = false;
2065
2066                 foreach ( $res as $row ) {
2067                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2068                         if ( $expiry > $now ) {
2069                                 if ( $getPages ) {
2070                                         $page_id = $row->pr_page;
2071                                         $page_ns = $row->page_namespace;
2072                                         $page_title = $row->page_title;
2073                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2074                                         # Add groups needed for each restriction type if its not already there
2075                                         # Make sure this restriction type still exists
2076
2077                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2078                                                 $pagerestrictions[$row->pr_type] = array();
2079                                         }
2080
2081                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2082                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2083                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2084                                         }
2085                                 } else {
2086                                         $sources = true;
2087                                 }
2088                         } else {
2089                                 // Trigger lazy purge of expired restrictions from the db
2090                                 $purgeExpired = true;
2091                         }
2092                 }
2093                 if ( $purgeExpired ) {
2094                         Title::purgeExpiredRestrictions();
2095                 }
2096
2097                 if ( $getPages ) {
2098                         $this->mCascadeSources = $sources;
2099                         $this->mCascadingRestrictions = $pagerestrictions;
2100                 } else {
2101                         $this->mHasCascadingRestrictions = $sources;
2102                 }
2103
2104                 wfProfileOut( __METHOD__ );
2105                 return array( $sources, $pagerestrictions );
2106         }
2107
2108         /**
2109          * Returns cascading restrictions for the current article
2110          *
2111          * @return Boolean
2112          */
2113         function areRestrictionsCascading() {
2114                 if ( !$this->mRestrictionsLoaded ) {
2115                         $this->loadRestrictions();
2116                 }
2117
2118                 return $this->mCascadeRestriction;
2119         }
2120
2121         /**
2122          * Loads a string into mRestrictions array
2123          *
2124          * @param $res Resource restrictions as an SQL result.
2125          * @param $oldFashionedRestrictions String comma-separated list of page
2126          *        restrictions from page table (pre 1.10)
2127          */
2128         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2129                 $rows = array();
2130
2131                 foreach ( $res as $row ) {
2132                         $rows[] = $row;
2133                 }
2134
2135                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2136         }
2137
2138         /**
2139          * Compiles list of active page restrictions from both page table (pre 1.10)
2140          * and page_restrictions table for this existing page.
2141          * Public for usage by LiquidThreads.
2142          *
2143          * @param $rows array of db result objects
2144          * @param $oldFashionedRestrictions string comma-separated list of page
2145          *        restrictions from page table (pre 1.10)
2146          */
2147         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2148                 global $wgContLang;
2149                 $dbr = wfGetDB( DB_SLAVE );
2150
2151                 $restrictionTypes = $this->getRestrictionTypes();
2152
2153                 foreach ( $restrictionTypes as $type ) {
2154                         $this->mRestrictions[$type] = array();
2155                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2156                 }
2157
2158                 $this->mCascadeRestriction = false;
2159
2160                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2161
2162                 if ( $oldFashionedRestrictions === null ) {
2163                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2164                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2165                 }
2166
2167                 if ( $oldFashionedRestrictions != '' ) {
2168
2169                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2170                                 $temp = explode( '=', trim( $restrict ) );
2171                                 if ( count( $temp ) == 1 ) {
2172                                         // old old format should be treated as edit/move restriction
2173                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2174                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2175                                 } else {
2176                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2177                                 }
2178                         }
2179
2180                         $this->mOldRestrictions = true;
2181
2182                 }
2183
2184                 if ( count( $rows ) ) {
2185                         # Current system - load second to make them override.
2186                         $now = wfTimestampNow();
2187                         $purgeExpired = false;
2188
2189                         # Cycle through all the restrictions.
2190                         foreach ( $rows as $row ) {
2191
2192                                 // Don't take care of restrictions types that aren't allowed
2193                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2194                                         continue;
2195
2196                                 // This code should be refactored, now that it's being used more generally,
2197                                 // But I don't really see any harm in leaving it in Block for now -werdna
2198                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2199
2200                                 // Only apply the restrictions if they haven't expired!
2201                                 if ( !$expiry || $expiry > $now ) {
2202                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2203                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2204
2205                                         $this->mCascadeRestriction |= $row->pr_cascade;
2206                                 } else {
2207                                         // Trigger a lazy purge of expired restrictions
2208                                         $purgeExpired = true;
2209                                 }
2210                         }
2211
2212                         if ( $purgeExpired ) {
2213                                 Title::purgeExpiredRestrictions();
2214                         }
2215                 }
2216
2217                 $this->mRestrictionsLoaded = true;
2218         }
2219
2220         /**
2221          * Load restrictions from the page_restrictions table
2222          *
2223          * @param $oldFashionedRestrictions String comma-separated list of page
2224          *        restrictions from page table (pre 1.10)
2225          */
2226         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2227                 global $wgContLang;
2228                 if ( !$this->mRestrictionsLoaded ) {
2229                         if ( $this->exists() ) {
2230                                 $dbr = wfGetDB( DB_SLAVE );
2231
2232                                 $res = $dbr->select(
2233                                         'page_restrictions',
2234                                         '*',
2235                                         array( 'pr_page' => $this->getArticleId() ),
2236                                         __METHOD__
2237                                 );
2238
2239                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2240                         } else {
2241                                 $title_protection = $this->getTitleProtection();
2242
2243                                 if ( $title_protection ) {
2244                                         $now = wfTimestampNow();
2245                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2246
2247                                         if ( !$expiry || $expiry > $now ) {
2248                                                 // Apply the restrictions
2249                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2250                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2251                                         } else { // Get rid of the old restrictions
2252                                                 Title::purgeExpiredRestrictions();
2253                                                 $this->mTitleProtection = false;
2254                                         }
2255                                 } else {
2256                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2257                                 }
2258                                 $this->mRestrictionsLoaded = true;
2259                         }
2260                 }
2261         }
2262
2263         /**
2264          * Purge expired restrictions from the page_restrictions table
2265          */
2266         static function purgeExpiredRestrictions() {
2267                 $dbw = wfGetDB( DB_MASTER );
2268                 $dbw->delete(
2269                         'page_restrictions',
2270                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2271                         __METHOD__
2272                 );
2273
2274                 $dbw->delete(
2275                         'protected_titles',
2276                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2277                         __METHOD__
2278                 );
2279         }
2280
2281         /**
2282          * Accessor/initialisation for mRestrictions
2283          *
2284          * @param $action String action that permission needs to be checked for
2285          * @return Array of Strings the array of groups allowed to edit this article
2286          */
2287         public function getRestrictions( $action ) {
2288                 if ( !$this->mRestrictionsLoaded ) {
2289                         $this->loadRestrictions();
2290                 }
2291                 return isset( $this->mRestrictions[$action] )
2292                                 ? $this->mRestrictions[$action]
2293                                 : array();
2294         }
2295
2296         /**
2297          * Get the expiry time for the restriction against a given action
2298          *
2299          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2300          *      or not protected at all, or false if the action is not recognised.
2301          */
2302         public function getRestrictionExpiry( $action ) {
2303                 if ( !$this->mRestrictionsLoaded ) {
2304                         $this->loadRestrictions();
2305                 }
2306                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2307         }
2308
2309         /**
2310          * Is there a version of this page in the deletion archive?
2311          *
2312          * @return Int the number of archived revisions
2313          */
2314         public function isDeleted() {
2315                 if ( $this->getNamespace() < 0 ) {
2316                         $n = 0;
2317                 } else {
2318                         $dbr = wfGetDB( DB_SLAVE );
2319                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2320                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2321                                 __METHOD__
2322                         );
2323                         if ( $this->getNamespace() == NS_FILE ) {
2324                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2325                                         array( 'fa_name' => $this->getDBkey() ),
2326                                         __METHOD__
2327                                 );
2328                         }
2329                 }
2330                 return (int)$n;
2331         }
2332
2333         /**
2334          * Is there a version of this page in the deletion archive?
2335          *
2336          * @return Boolean
2337          */
2338         public function isDeletedQuick() {
2339                 if ( $this->getNamespace() < 0 ) {
2340                         return false;
2341                 }
2342                 $dbr = wfGetDB( DB_SLAVE );
2343                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2344                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2345                         __METHOD__
2346                 );
2347                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2348                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2349                                 array( 'fa_name' => $this->getDBkey() ),
2350                                 __METHOD__
2351                         );
2352                 }
2353                 return $deleted;
2354         }
2355
2356         /**
2357          * Get the article ID for this Title from the link cache,
2358          * adding it if necessary
2359          *
2360          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2361          *  for update
2362          * @return Int the ID
2363          */
2364         public function getArticleID( $flags = 0 ) {
2365                 if ( $this->getNamespace() < 0 ) {
2366                         return $this->mArticleID = 0;
2367                 }
2368                 $linkCache = LinkCache::singleton();
2369                 if ( $flags & self::GAID_FOR_UPDATE ) {
2370                         $oldUpdate = $linkCache->forUpdate( true );
2371                         $linkCache->clearLink( $this );
2372                         $this->mArticleID = $linkCache->addLinkObj( $this );
2373                         $linkCache->forUpdate( $oldUpdate );
2374                 } else {
2375                         if ( -1 == $this->mArticleID ) {
2376                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2377                         }
2378                 }
2379                 return $this->mArticleID;
2380         }
2381
2382         /**
2383          * Is this an article that is a redirect page?
2384          * Uses link cache, adding it if necessary
2385          *
2386          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2387          * @return Bool
2388          */
2389         public function isRedirect( $flags = 0 ) {
2390                 if ( !is_null( $this->mRedirect ) ) {
2391                         return $this->mRedirect;
2392                 }
2393                 # Calling getArticleID() loads the field from cache as needed
2394                 if ( !$this->getArticleID( $flags ) ) {
2395                         return $this->mRedirect = false;
2396                 }
2397                 $linkCache = LinkCache::singleton();
2398                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2399
2400                 return $this->mRedirect;
2401         }
2402
2403         /**
2404          * What is the length of this page?
2405          * Uses link cache, adding it if necessary
2406          *
2407          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2408          * @return Int
2409          */
2410         public function getLength( $flags = 0 ) {
2411                 if ( $this->mLength != -1 ) {
2412                         return $this->mLength;
2413                 }
2414                 # Calling getArticleID() loads the field from cache as needed
2415                 if ( !$this->getArticleID( $flags ) ) {
2416                         return $this->mLength = 0;
2417                 }
2418                 $linkCache = LinkCache::singleton();
2419                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2420
2421                 return $this->mLength;
2422         }
2423
2424         /**
2425          * What is the page_latest field for this page?
2426          *
2427          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2428          * @return Int or 0 if the page doesn't exist
2429          */
2430         public function getLatestRevID( $flags = 0 ) {
2431                 if ( $this->mLatestID !== false ) {
2432                         return intval( $this->mLatestID );
2433                 }
2434                 # Calling getArticleID() loads the field from cache as needed
2435                 if ( !$this->getArticleID( $flags ) ) {
2436                         return $this->mLatestID = 0;
2437                 }
2438                 $linkCache = LinkCache::singleton();
2439                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2440
2441                 return $this->mLatestID;
2442         }
2443
2444         /**
2445          * This clears some fields in this object, and clears any associated
2446          * keys in the "bad links" section of the link cache.
2447          *
2448          * - This is called from Article::doEdit() and Article::insertOn() to allow
2449          * loading of the new page_id. It's also called from
2450          * Article::doDeleteArticle()
2451          *
2452          * @param $newid Int the new Article ID
2453          */
2454         public function resetArticleID( $newid ) {
2455                 $linkCache = LinkCache::singleton();
2456                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2457
2458                 if ( $newid === false ) {
2459                         $this->mArticleID = -1;
2460                 } else {
2461                         $this->mArticleID = intval( $newid );
2462                 }
2463                 $this->mRestrictionsLoaded = false;
2464                 $this->mRestrictions = array();
2465                 $this->mRedirect = null;
2466                 $this->mLength = -1;
2467                 $this->mLatestID = false;
2468         }
2469
2470         /**
2471          * Updates page_touched for this page; called from LinksUpdate.php
2472          *
2473          * @return Bool true if the update succeded
2474          */
2475         public function invalidateCache() {
2476                 if ( wfReadOnly() ) {
2477                         return;
2478                 }
2479                 $dbw = wfGetDB( DB_MASTER );
2480                 $success = $dbw->update(
2481                         'page',
2482                         array( 'page_touched' => $dbw->timestamp() ),
2483                         $this->pageCond(),
2484                         __METHOD__
2485                 );
2486                 HTMLFileCache::clearFileCache( $this );
2487                 return $success;
2488         }
2489
2490         /**
2491          * Prefix some arbitrary text with the namespace or interwiki prefix
2492          * of this object
2493          *
2494          * @param $name String the text
2495          * @return String the prefixed text
2496          * @private
2497          */
2498         private function prefix( $name ) {
2499                 $p = '';
2500                 if ( $this->mInterwiki != '' ) {
2501                         $p = $this->mInterwiki . ':';
2502                 }
2503
2504                 if ( 0 != $this->mNamespace ) {
2505                         $p .= $this->getNsText() . ':';
2506                 }
2507                 return $p . $name;
2508         }
2509
2510         /**
2511          * Returns a simple regex that will match on characters and sequences invalid in titles.
2512          * Note that this doesn't pick up many things that could be wrong with titles, but that
2513          * replacing this regex with something valid will make many titles valid.
2514          *
2515          * @return String regex string
2516          */
2517         static function getTitleInvalidRegex() {
2518                 static $rxTc = false;
2519                 if ( !$rxTc ) {
2520                         # Matching titles will be held as illegal.
2521                         $rxTc = '/' .
2522                                 # Any character not allowed is forbidden...
2523                                 '[^' . Title::legalChars() . ']' .
2524                                 # URL percent encoding sequences interfere with the ability
2525                                 # to round-trip titles -- you can't link to them consistently.
2526                                 '|%[0-9A-Fa-f]{2}' .
2527                                 # XML/HTML character references produce similar issues.
2528                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2529                                 '|&#[0-9]+;' .
2530                                 '|&#x[0-9A-Fa-f]+;' .
2531                                 '/S';
2532                 }
2533
2534                 return $rxTc;
2535         }
2536
2537         /**
2538          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2539          *
2540          * @param $text String containing title to capitalize
2541          * @param $ns int namespace index, defaults to NS_MAIN
2542          * @return String containing capitalized title
2543          */
2544         public static function capitalize( $text, $ns = NS_MAIN ) {
2545                 global $wgContLang;
2546
2547                 if ( MWNamespace::isCapitalized( $ns ) ) {
2548                         return $wgContLang->ucfirst( $text );
2549                 } else {
2550                         return $text;
2551                 }
2552         }
2553
2554         /**
2555          * Secure and split - main initialisation function for this object
2556          *
2557          * Assumes that mDbkeyform has been set, and is urldecoded
2558          * and uses underscores, but not otherwise munged.  This function
2559          * removes illegal characters, splits off the interwiki and
2560          * namespace prefixes, sets the other forms, and canonicalizes
2561          * everything.
2562          *
2563          * @return Bool true on success
2564          */
2565         private function secureAndSplit() {
2566                 global $wgContLang, $wgLocalInterwiki;
2567
2568                 # Initialisation
2569                 $this->mInterwiki = $this->mFragment = '';
2570                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2571
2572                 $dbkey = $this->mDbkeyform;
2573
2574                 # Strip Unicode bidi override characters.
2575                 # Sometimes they slip into cut-n-pasted page titles, where the
2576                 # override chars get included in list displays.
2577                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2578
2579                 # Clean up whitespace
2580                 # Note: use of the /u option on preg_replace here will cause
2581                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2582                 # conveniently disabling them.
2583                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2584                 $dbkey = trim( $dbkey, '_' );
2585
2586                 if ( $dbkey == '' ) {
2587                         return false;
2588                 }
2589
2590                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2591                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2592                         return false;
2593                 }
2594
2595                 $this->mDbkeyform = $dbkey;
2596
2597                 # Initial colon indicates main namespace rather than specified default
2598                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2599                 if ( ':' == $dbkey[0] ) {
2600                         $this->mNamespace = NS_MAIN;
2601                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2602                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2603                 }
2604
2605                 # Namespace or interwiki prefix
2606                 $firstPass = true;
2607                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2608                 do {
2609                         $m = array();
2610                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2611                                 $p = $m[1];
2612                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2613                                         # Ordinary namespace
2614                                         $dbkey = $m[2];
2615                                         $this->mNamespace = $ns;
2616                                         # For Talk:X pages, check if X has a "namespace" prefix
2617                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2618                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2619                                                         # Disallow Talk:File:x type titles...
2620                                                         return false;
2621                                                 } elseif ( Interwiki::isValidInterwiki( $x[1] ) ) {
2622                                                         # Disallow Talk:Interwiki:x type titles...
2623                                                         return false;
2624                                                 }
2625                                         }
2626                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2627                                         if ( !$firstPass ) {
2628                                                 # Can't make a local interwiki link to an interwiki link.
2629                                                 # That's just crazy!
2630                                                 return false;
2631                                         }
2632
2633                                         # Interwiki link
2634                                         $dbkey = $m[2];
2635                                         $this->mInterwiki = $wgContLang->lc( $p );
2636
2637                                         # Redundant interwiki prefix to the local wiki
2638                                         if ( $wgLocalInterwiki !== false
2639                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2640                                         {
2641                                                 if ( $dbkey == '' ) {
2642                                                         # Can't have an empty self-link
2643                                                         return false;
2644                                                 }
2645                                                 $this->mInterwiki = '';
2646                                                 $firstPass = false;
2647                                                 # Do another namespace split...
2648                                                 continue;
2649                                         }
2650
2651                                         # If there's an initial colon after the interwiki, that also
2652                                         # resets the default namespace
2653                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2654                                                 $this->mNamespace = NS_MAIN;
2655                                                 $dbkey = substr( $dbkey, 1 );
2656                                         }
2657                                 }
2658                                 # If there's no recognized interwiki or namespace,
2659                                 # then let the colon expression be part of the title.
2660                         }
2661                         break;
2662                 } while ( true );
2663
2664                 # We already know that some pages won't be in the database!
2665                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2666                         $this->mArticleID = 0;
2667                 }
2668                 $fragment = strstr( $dbkey, '#' );
2669                 if ( false !== $fragment ) {
2670                         $this->setFragment( $fragment );
2671                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2672                         # remove whitespace again: prevents "Foo_bar_#"
2673                         # becoming "Foo_bar_"
2674                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2675                 }
2676
2677                 # Reject illegal characters.
2678                 $rxTc = self::getTitleInvalidRegex();
2679                 if ( preg_match( $rxTc, $dbkey ) ) {
2680                         return false;
2681                 }
2682
2683                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2684                 # reachable due to the way web browsers deal with 'relative' URLs.
2685                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2686                 if ( strpos( $dbkey, '.' ) !== false &&
2687                          ( $dbkey === '.' || $dbkey === '..' ||
2688                            strpos( $dbkey, './' ) === 0  ||
2689                            strpos( $dbkey, '../' ) === 0 ||
2690                            strpos( $dbkey, '/./' ) !== false ||
2691                            strpos( $dbkey, '/../' ) !== false  ||
2692                            substr( $dbkey, -2 ) == '/.' ||
2693                            substr( $dbkey, -3 ) == '/..' ) )
2694                 {
2695                         return false;
2696                 }
2697
2698                 # Magic tilde sequences? Nu-uh!
2699                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2700                         return false;
2701                 }
2702
2703                 # Limit the size of titles to 255 bytes. This is typically the size of the
2704                 # underlying database field. We make an exception for special pages, which
2705                 # don't need to be stored in the database, and may edge over 255 bytes due
2706                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2707                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2708                   strlen( $dbkey ) > 512 )
2709                 {
2710                         return false;
2711                 }
2712
2713                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2714                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2715                 # other site might be case-sensitive.
2716                 $this->mUserCaseDBKey = $dbkey;
2717                 if ( $this->mInterwiki == '' ) {
2718                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2719                 }
2720
2721                 # Can't make a link to a namespace alone... "empty" local links can only be
2722                 # self-links with a fragment identifier.
2723                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2724                         return false;
2725                 }
2726
2727                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2728                 // IP names are not allowed for accounts, and can only be referring to
2729                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2730                 // there are numerous ways to present the same IP. Having sp:contribs scan
2731                 // them all is silly and having some show the edits and others not is
2732                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2733                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2734                         ? IP::sanitizeIP( $dbkey )
2735                         : $dbkey;
2736
2737                 // Any remaining initial :s are illegal.
2738                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2739                         return false;
2740                 }
2741
2742                 # Fill fields
2743                 $this->mDbkeyform = $dbkey;
2744                 $this->mUrlform = wfUrlencode( $dbkey );
2745
2746                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2747
2748                 return true;
2749         }
2750
2751         /**
2752          * Set the fragment for this title. Removes the first character from the
2753          * specified fragment before setting, so it assumes you're passing it with
2754          * an initial "#".
2755          *
2756          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2757          * Still in active use privately.
2758          *
2759          * @param $fragment String text
2760          */
2761         public function setFragment( $fragment ) {
2762                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2763         }
2764
2765         /**
2766          * Get a Title object associated with the talk page of this article
2767          *
2768          * @return Title the object for the talk page
2769          */
2770         public function getTalkPage() {
2771                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2772         }
2773
2774         /**
2775          * Get a title object associated with the subject page of this
2776          * talk page
2777          *
2778          * @return Title the object for the subject page
2779          */
2780         public function getSubjectPage() {
2781                 // Is this the same title?
2782                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2783                 if ( $this->getNamespace() == $subjectNS ) {
2784                         return $this;
2785                 }
2786                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2787         }
2788
2789         /**
2790          * Get an array of Title objects linking to this Title
2791          * Also stores the IDs in the link cache.
2792          *
2793          * WARNING: do not use this function on arbitrary user-supplied titles!
2794          * On heavily-used templates it will max out the memory.
2795          *
2796          * @param $options Array: may be FOR UPDATE
2797          * @param $table String: table name
2798          * @param $prefix String: fields prefix
2799          * @return Array of Title objects linking here
2800          */
2801         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2802                 $linkCache = LinkCache::singleton();
2803
2804                 if ( count( $options ) > 0 ) {
2805                         $db = wfGetDB( DB_MASTER );
2806                 } else {
2807                         $db = wfGetDB( DB_SLAVE );
2808                 }
2809
2810                 $res = $db->select(
2811                         array( 'page', $table ),
2812                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2813                         array(
2814                                 "{$prefix}_from=page_id",
2815                                 "{$prefix}_namespace" => $this->getNamespace(),
2816                                 "{$prefix}_title"     => $this->getDBkey() ),
2817                         __METHOD__,
2818                         $options
2819                 );
2820
2821                 $retVal = array();
2822                 if ( $db->numRows( $res ) ) {
2823                         foreach ( $res as $row ) {
2824                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2825                                 if ( $titleObj ) {
2826                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2827                                         $retVal[] = $titleObj;
2828                                 }
2829                         }
2830                 }
2831                 return $retVal;
2832         }
2833
2834         /**
2835          * Get an array of Title objects using this Title as a template
2836          * Also stores the IDs in the link cache.
2837          *
2838          * WARNING: do not use this function on arbitrary user-supplied titles!
2839          * On heavily-used templates it will max out the memory.
2840          *
2841          * @param $options Array: may be FOR UPDATE
2842          * @return Array of Title the Title objects linking here
2843          */
2844         public function getTemplateLinksTo( $options = array() ) {
2845                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2846         }
2847
2848         /**
2849          * Get an array of Title objects referring to non-existent articles linked from this page
2850          *
2851          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2852          * @return Array of Title the Title objects
2853          */
2854         public function getBrokenLinksFrom() {
2855                 if ( $this->getArticleId() == 0 ) {
2856                         # All links from article ID 0 are false positives
2857                         return array();
2858                 }
2859
2860                 $dbr = wfGetDB( DB_SLAVE );
2861                 $res = $dbr->select(
2862                         array( 'page', 'pagelinks' ),
2863                         array( 'pl_namespace', 'pl_title' ),
2864                         array(
2865                                 'pl_from' => $this->getArticleId(),
2866                                 'page_namespace IS NULL'
2867                         ),
2868                         __METHOD__, array(),
2869                         array(
2870                                 'page' => array(
2871                                         'LEFT JOIN',
2872                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2873                                 )
2874                         )
2875                 );
2876
2877                 $retVal = array();
2878                 foreach ( $res as $row ) {
2879                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2880                 }
2881                 return $retVal;
2882         }
2883
2884
2885         /**
2886          * Get a list of URLs to purge from the Squid cache when this
2887          * page changes
2888          *
2889          * @return Array of String the URLs
2890          */
2891         public function getSquidURLs() {
2892                 global $wgContLang;
2893
2894                 $urls = array(
2895                         $this->getInternalURL(),
2896                         $this->getInternalURL( 'action=history' )
2897                 );
2898
2899                 // purge variant urls as well
2900                 if ( $wgContLang->hasVariants() ) {
2901                         $variants = $wgContLang->getVariants();
2902                         foreach ( $variants as $vCode ) {
2903                                 $urls[] = $this->getInternalURL( '', $vCode );
2904                         }
2905                 }
2906
2907                 return $urls;
2908         }
2909
2910         /**
2911          * Purge all applicable Squid URLs
2912          */
2913         public function purgeSquid() {
2914                 global $wgUseSquid;
2915                 if ( $wgUseSquid ) {
2916                         $urls = $this->getSquidURLs();
2917                         $u = new SquidUpdate( $urls );
2918                         $u->doUpdate();
2919                 }
2920         }
2921
2922         /**
2923          * Move this page without authentication
2924          *
2925          * @param $nt Title the new page Title
2926          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
2927          */
2928         public function moveNoAuth( &$nt ) {
2929                 return $this->moveTo( $nt, false );
2930         }
2931
2932         /**
2933          * Check whether a given move operation would be valid.
2934          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2935          *
2936          * @param $nt Title the new title
2937          * @param $auth Bool indicates whether $wgUser's permissions
2938          *  should be checked
2939          * @param $reason String is the log summary of the move, used for spam checking
2940          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
2941          */
2942         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2943                 global $wgUser;
2944
2945                 $errors = array();
2946                 if ( !$nt ) {
2947                         // Normally we'd add this to $errors, but we'll get
2948                         // lots of syntax errors if $nt is not an object
2949                         return array( array( 'badtitletext' ) );
2950                 }
2951                 if ( $this->equals( $nt ) ) {
2952                         $errors[] = array( 'selfmove' );
2953                 }
2954                 if ( !$this->isMovable() ) {
2955                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2956                 }
2957                 if ( $nt->getInterwiki() != '' ) {
2958                         $errors[] = array( 'immobile-target-namespace-iw' );
2959                 }
2960                 if ( !$nt->isMovable() ) {
2961                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
2962                 }
2963
2964                 $oldid = $this->getArticleID();
2965                 $newid = $nt->getArticleID();
2966
2967                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2968                         $errors[] = array( 'articleexists' );
2969                 }
2970                 if ( ( $this->getDBkey() == '' ) ||
2971                          ( !$oldid ) ||
2972                          ( $nt->getDBkey() == '' ) ) {
2973                         $errors[] = array( 'badarticleerror' );
2974                 }
2975
2976                 // Image-specific checks
2977                 if ( $this->getNamespace() == NS_FILE ) {
2978                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
2979                 }
2980
2981                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
2982                         $errors[] = array( 'nonfile-cannot-move-to-file' );
2983                 }
2984
2985                 if ( $auth ) {
2986                         $errors = wfMergeErrorArrays( $errors,
2987                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
2988                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
2989                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
2990                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
2991                 }
2992
2993                 $match = EditPage::matchSummarySpamRegex( $reason );
2994                 if ( $match !== false ) {
2995                         // This is kind of lame, won't display nice
2996                         $errors[] = array( 'spamprotectiontext' );
2997                 }
2998
2999                 $err = null;
3000                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3001                         $errors[] = array( 'hookaborted', $err );
3002                 }
3003
3004                 # The move is allowed only if (1) the target doesn't exist, or
3005                 # (2) the target is a redirect to the source, and has no history
3006                 # (so we can undo bad moves right after they're done).
3007
3008                 if ( 0 != $newid ) { # Target exists; check for validity
3009                         if ( !$this->isValidMoveTarget( $nt ) ) {
3010                                 $errors[] = array( 'articleexists' );
3011                         }
3012                 } else {
3013                         $tp = $nt->getTitleProtection();
3014                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3015                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3016                                 $errors[] = array( 'cantmove-titleprotected' );
3017                         }
3018                 }
3019                 if ( empty( $errors ) ) {
3020                         return true;
3021                 }
3022                 return $errors;
3023         }
3024
3025         /**
3026          * Check if the requested move target is a valid file move target
3027          * @param Title $nt Target title
3028          * @return array List of errors
3029          */
3030         protected function validateFileMoveOperation( $nt ) {
3031                 global $wgUser;
3032
3033                 $errors = array();
3034
3035                 if ( $nt->getNamespace() != NS_FILE ) {
3036                         $errors[] = array( 'imagenocrossnamespace' );
3037                 }
3038
3039                 $file = wfLocalFile( $this );
3040                 if ( $file->exists() ) {
3041                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3042                                 $errors[] = array( 'imageinvalidfilename' );
3043                         }
3044                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3045                                 $errors[] = array( 'imagetypemismatch' );
3046                         }
3047                 }
3048
3049                 $destFile = wfLocalFile( $nt );
3050                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3051                         $errors[] = array( 'file-exists-sharedrepo' );
3052                 }
3053
3054                 return $errors;
3055         }
3056
3057         /**
3058          * Move a title to a new location
3059          *
3060          * @param $nt Title the new title
3061          * @param $auth Bool indicates whether $wgUser's permissions
3062          *  should be checked
3063          * @param $reason String the reason for the move
3064          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3065          *  Ignored if the user doesn't have the suppressredirect right.
3066          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3067          */
3068         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3069                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3070                 if ( is_array( $err ) ) {
3071                         return $err;
3072                 }
3073
3074                 // If it is a file, move it first. It is done before all other moving stuff is
3075                 // done because it's hard to revert
3076                 $dbw = wfGetDB( DB_MASTER );
3077                 if ( $this->getNamespace() == NS_FILE ) {
3078                         $file = wfLocalFile( $this );
3079                         if ( $file->exists() ) {
3080                                 $status = $file->move( $nt );
3081                                 if ( !$status->isOk() ) {
3082                                         return $status->getErrorsArray();
3083                                 }
3084                         }
3085                 }
3086
3087                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3088                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3089                 $protected = $this->isProtected();
3090                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3091
3092                 // Do the actual move
3093                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3094                 if ( is_array( $err ) ) {
3095                         # @todo FIXME: What about the File we have already moved?
3096                         $dbw->rollback();
3097                         return $err;
3098                 }
3099
3100                 $redirid = $this->getArticleID();
3101
3102                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3103                 // cl_timestamp, which may disturb time-based lists on some sites.
3104                 $prefixes = $dbw->select(
3105                         'categorylinks',
3106                         array( 'cl_sortkey_prefix', 'cl_to' ),
3107                         array( 'cl_from' => $pageid ),
3108                         __METHOD__
3109                 );
3110                 foreach ( $prefixes as $prefixRow ) {
3111                         $prefix = $prefixRow->cl_sortkey_prefix;
3112                         $catTo = $prefixRow->cl_to;
3113                         $dbw->update( 'categorylinks',
3114                                 array(
3115                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3116                                                 $nt->getCategorySortkey( $prefix ) ),
3117                                         'cl_timestamp=cl_timestamp' ),
3118                                 array(
3119                                         'cl_from' => $pageid,
3120                                         'cl_to' => $catTo ),
3121                                 __METHOD__
3122                         );
3123                 }
3124
3125                 if ( $protected ) {
3126                         # Protect the redirect title as the title used to be...
3127                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3128                                 array(
3129                                         'pr_page'    => $redirid,
3130                                         'pr_type'    => 'pr_type',
3131                                         'pr_level'   => 'pr_level',
3132                                         'pr_cascade' => 'pr_cascade',
3133                                         'pr_user'    => 'pr_user',
3134                                         'pr_expiry'  => 'pr_expiry'
3135                                 ),
3136                                 array( 'pr_page' => $pageid ),
3137                                 __METHOD__,
3138                                 array( 'IGNORE' )
3139                         );
3140                         # Update the protection log
3141                         $log = new LogPage( 'protect' );
3142                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3143                         if ( $reason ) {
3144                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3145                         }
3146                         // @todo FIXME: $params?
3147                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) );
3148                 }
3149
3150                 # Update watchlists
3151                 $oldnamespace = $this->getNamespace() & ~1;
3152                 $newnamespace = $nt->getNamespace() & ~1;
3153                 $oldtitle = $this->getDBkey();
3154                 $newtitle = $nt->getDBkey();
3155
3156                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3157                         WatchedItem::duplicateEntries( $this, $nt );
3158                 }
3159
3160                 # Update search engine
3161                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3162                 $u->doUpdate();
3163                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3164                 $u->doUpdate();
3165
3166                 $dbw->commit();
3167
3168                 # Update site_stats
3169                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3170                         # No longer a content page
3171                         # Not viewed, edited, removing
3172                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3173                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3174                         # Now a content page
3175                         # Not viewed, edited, adding
3176                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3177                 } elseif ( $pageCountChange ) {
3178                         # Redirect added
3179                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3180                 } else {
3181                         # Nothing special
3182                         $u = false;
3183                 }
3184                 if ( $u ) {
3185                         $u->doUpdate();
3186                 }
3187                 # Update message cache for interface messages
3188                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3189                         # @bug 17860: old article can be deleted, if this the case,
3190                         # delete it from message cache
3191                         if ( $this->getArticleID() === 0 ) {
3192                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3193                         } else {
3194                                 $oldarticle = new Article( $this );
3195                                 MessageCache::singleton()->replace( $this->getDBkey(), $oldarticle->getContent() );
3196                         }
3197                 }
3198                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3199                         $newarticle = new Article( $nt );
3200                         MessageCache::singleton()->replace( $nt->getDBkey(), $newarticle->getContent() );
3201                 }
3202
3203                 global $wgUser;
3204                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3205                 return true;
3206         }
3207
3208         /**
3209          * Move page to a title which is either a redirect to the
3210          * source page or nonexistent
3211          *
3212          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3213          * @param $reason String The reason for the move
3214          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3215          *   if the user doesn't have the suppressredirect right
3216          */
3217         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3218                 global $wgUser, $wgContLang;
3219
3220                 $moveOverRedirect = $nt->exists();
3221
3222                 $commentMsg = ( $moveOverRedirect ? '1movedto2_redir' : '1movedto2' );
3223                 $comment = wfMsgForContent( $commentMsg, $this->getPrefixedText(), $nt->getPrefixedText() );
3224
3225                 if ( $reason ) {
3226                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3227                 }
3228                 # Truncate for whole multibyte characters.
3229                 $comment = $wgContLang->truncate( $comment, 255 );
3230
3231                 $oldid = $this->getArticleID();
3232                 $latest = $this->getLatestRevID();
3233
3234                 $oldns = $this->getNamespace();
3235                 $olddbk = $this->getDBkey();
3236
3237                 $dbw = wfGetDB( DB_MASTER );
3238
3239                 if ( $moveOverRedirect ) {
3240                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3241
3242                         $newid = $nt->getArticleID();
3243                         $newns = $nt->getNamespace();
3244                         $newdbk = $nt->getDBkey();
3245
3246                         # Delete the old redirect. We don't save it to history since
3247                         # by definition if we've got here it's rather uninteresting.
3248                         # We have to remove it so that the next step doesn't trigger
3249                         # a conflict on the unique namespace+title index...
3250                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3251                         if ( !$dbw->cascadingDeletes() ) {
3252                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3253                                 global $wgUseTrackbacks;
3254                                 if ( $wgUseTrackbacks ) {
3255                                         $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3256                                 }
3257                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3258                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3259                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3260                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3261                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3262                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3263                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3264                         }
3265                         // If the target page was recently created, it may have an entry in recentchanges still
3266                         $dbw->delete( 'recentchanges',
3267                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3268                                 __METHOD__
3269                         );
3270                 }
3271
3272                 # Save a null revision in the page's history notifying of the move
3273                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3274                 if ( !is_object( $nullRevision ) ) {
3275                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3276                 }
3277                 $nullRevId = $nullRevision->insertOn( $dbw );
3278
3279                 # Change the name of the target page:
3280                 $dbw->update( 'page',
3281                         /* SET */ array(
3282                                 'page_touched'   => $dbw->timestamp(),
3283                                 'page_namespace' => $nt->getNamespace(),
3284                                 'page_title'     => $nt->getDBkey(),
3285                                 'page_latest'    => $nullRevId,
3286                         ),
3287                         /* WHERE */ array( 'page_id' => $oldid ),
3288                         __METHOD__
3289                 );
3290                 $nt->resetArticleID( $oldid );
3291
3292                 $article = new Article( $nt );
3293                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3294
3295                 # Recreate the redirect, this time in the other direction.
3296                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3297                         $mwRedir = MagicWord::get( 'redirect' );
3298                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3299                         $redirectArticle = new Article( $this );
3300                         $newid = $redirectArticle->insertOn( $dbw );
3301                         $redirectRevision = new Revision( array(
3302                                 'page'    => $newid,
3303                                 'comment' => $comment,
3304                                 'text'    => $redirectText ) );
3305                         $redirectRevision->insertOn( $dbw );
3306                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3307
3308                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3309
3310                         # Now, we record the link from the redirect to the new title.
3311                         # It should have no other outgoing links...
3312                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3313                         $dbw->insert( 'pagelinks',
3314                                 array(
3315                                         'pl_from'      => $newid,
3316                                         'pl_namespace' => $nt->getNamespace(),
3317                                         'pl_title'     => $nt->getDBkey() ),
3318                                 __METHOD__ );
3319                         $redirectSuppressed = false;
3320                 } else {
3321                         // Get rid of old new page entries in Special:NewPages and RC.
3322                         // Needs to be before $this->resetArticleID( 0 ).
3323                         $dbw->delete( 'recentchanges', array(
3324                                         'rc_timestamp' => $dbw->timestamp( $this->getEarliestRevTime() ),
3325                                         'rc_namespace' => $oldns,
3326                                         'rc_title' => $olddbk,
3327                                         'rc_new' => 1
3328                                 ),
3329                                 __METHOD__
3330                         );
3331
3332                         $this->resetArticleID( 0 );
3333                         $redirectSuppressed = true;
3334                 }
3335
3336                 # Log the move
3337                 $log = new LogPage( 'move' );
3338                 $logType = ( $moveOverRedirect ? 'move_redir' : 'move' );
3339                 $log->addEntry( $logType, $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3340
3341                 # Purge caches for old and new titles
3342                 if ( $moveOverRedirect ) {
3343                         # A simple purge is enough when moving over a redirect
3344                         $nt->purgeSquid();
3345                 } else {
3346                         # Purge caches as per article creation, including any pages that link to this title
3347                         Article::onArticleCreate( $nt );
3348                 }
3349                 $this->purgeSquid();
3350         }
3351
3352         /**
3353          * Move this page's subpages to be subpages of $nt
3354          *
3355          * @param $nt Title Move target
3356          * @param $auth bool Whether $wgUser's permissions should be checked
3357          * @param $reason string The reason for the move
3358          * @param $createRedirect bool Whether to create redirects from the old subpages to
3359          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3360          * @return mixed array with old page titles as keys, and strings (new page titles) or
3361          *     arrays (errors) as values, or an error array with numeric indices if no pages
3362          *     were moved
3363          */
3364         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3365                 global $wgMaximumMovedPages;
3366                 // Check permissions
3367                 if ( !$this->userCan( 'move-subpages' ) ) {
3368                         return array( 'cant-move-subpages' );
3369                 }
3370                 // Do the source and target namespaces support subpages?
3371                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3372                         return array( 'namespace-nosubpages',
3373                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3374                 }
3375                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3376                         return array( 'namespace-nosubpages',
3377                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3378                 }
3379
3380                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3381                 $retval = array();
3382                 $count = 0;
3383                 foreach ( $subpages as $oldSubpage ) {
3384                         $count++;
3385                         if ( $count > $wgMaximumMovedPages ) {
3386                                 $retval[$oldSubpage->getPrefixedTitle()] =
3387                                                 array( 'movepage-max-pages',
3388                                                         $wgMaximumMovedPages );
3389                                 break;
3390                         }
3391
3392                         // We don't know whether this function was called before
3393                         // or after moving the root page, so check both
3394                         // $this and $nt
3395                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3396                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3397                         {
3398                                 // When moving a page to a subpage of itself,
3399                                 // don't move it twice
3400                                 continue;
3401                         }
3402                         $newPageName = preg_replace(
3403                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3404                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3405                                         $oldSubpage->getDBkey() );
3406                         if ( $oldSubpage->isTalkPage() ) {
3407                                 $newNs = $nt->getTalkPage()->getNamespace();
3408                         } else {
3409                                 $newNs = $nt->getSubjectPage()->getNamespace();
3410                         }
3411                         # Bug 14385: we need makeTitleSafe because the new page names may
3412                         # be longer than 255 characters.
3413                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3414
3415                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3416                         if ( $success === true ) {
3417                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3418                         } else {
3419                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3420                         }
3421                 }
3422                 return $retval;
3423         }
3424
3425         /**
3426          * Checks if this page is just a one-rev redirect.
3427          * Adds lock, so don't use just for light purposes.
3428          *
3429          * @return Bool
3430          */
3431         public function isSingleRevRedirect() {
3432                 $dbw = wfGetDB( DB_MASTER );
3433                 # Is it a redirect?
3434                 $row = $dbw->selectRow( 'page',
3435                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3436                         $this->pageCond(),
3437                         __METHOD__,
3438                         array( 'FOR UPDATE' )
3439                 );
3440                 # Cache some fields we may want
3441                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3442                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3443                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3444                 if ( !$this->mRedirect ) {
3445                         return false;
3446                 }
3447                 # Does the article have a history?
3448                 $row = $dbw->selectField( array( 'page', 'revision' ),
3449                         'rev_id',
3450                         array( 'page_namespace' => $this->getNamespace(),
3451                                 'page_title' => $this->getDBkey(),
3452                                 'page_id=rev_page',
3453                                 'page_latest != rev_id'
3454                         ),
3455                         __METHOD__,
3456                         array( 'FOR UPDATE' )
3457                 );
3458                 # Return true if there was no history
3459                 return ( $row === false );
3460         }
3461
3462         /**
3463          * Checks if $this can be moved to a given Title
3464          * - Selects for update, so don't call it unless you mean business
3465          *
3466          * @param $nt Title the new title to check
3467          * @return Bool
3468          */
3469         public function isValidMoveTarget( $nt ) {
3470                 # Is it an existing file?
3471                 if ( $nt->getNamespace() == NS_FILE ) {
3472                         $file = wfLocalFile( $nt );
3473                         if ( $file->exists() ) {
3474                                 wfDebug( __METHOD__ . ": file exists\n" );
3475                                 return false;
3476                         }
3477                 }
3478                 # Is it a redirect with no history?
3479                 if ( !$nt->isSingleRevRedirect() ) {
3480                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3481                         return false;
3482                 }
3483                 # Get the article text
3484                 $rev = Revision::newFromTitle( $nt );
3485                 $text = $rev->getText();
3486                 # Does the redirect point to the source?
3487                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3488                 $m = array();
3489                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3490                         $redirTitle = Title::newFromText( $m[1] );
3491                         if ( !is_object( $redirTitle ) ||
3492                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3493                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3494                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3495                                 return false;
3496                         }
3497                 } else {
3498                         # Fail safe
3499                         wfDebug( __METHOD__ . ": failsafe\n" );
3500                         return false;
3501                 }
3502                 return true;
3503         }
3504
3505         /**
3506          * Can this title be added to a user's watchlist?
3507          *
3508          * @return Bool TRUE or FALSE
3509          */
3510         public function isWatchable() {
3511                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3512         }
3513
3514         /**
3515          * Get categories to which this Title belongs and return an array of
3516          * categories' names.
3517          *
3518          * @return Array of parents in the form:
3519          *        $parent => $currentarticle
3520          */
3521         public function getParentCategories() {
3522                 global $wgContLang;
3523
3524                 $data = array();
3525
3526                 $titleKey = $this->getArticleId();
3527
3528                 if ( $titleKey === 0 ) {
3529                         return $data;
3530                 }
3531
3532                 $dbr = wfGetDB( DB_SLAVE );
3533
3534                 $res = $dbr->select( 'categorylinks', '*',
3535                         array(
3536                                 'cl_from' => $titleKey,
3537                         ),
3538                         __METHOD__,
3539                         array()
3540                 );
3541
3542                 if ( $dbr->numRows( $res ) > 0 ) {
3543                         foreach ( $res as $row ) {
3544                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3545                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3546                         }
3547                 }
3548                 return $data;
3549         }
3550
3551         /**
3552          * Get a tree of parent categories
3553          *
3554          * @param $children Array with the children in the keys, to check for circular refs
3555          * @return Array Tree of parent categories
3556          */
3557         public function getParentCategoryTree( $children = array() ) {
3558                 $stack = array();
3559                 $parents = $this->getParentCategories();
3560
3561                 if ( $parents ) {
3562                         foreach ( $parents as $parent => $current ) {
3563                                 if ( array_key_exists( $parent, $children ) ) {
3564                                         # Circular reference
3565                                         $stack[$parent] = array();
3566                                 } else {
3567                                         $nt = Title::newFromText( $parent );
3568                                         if ( $nt ) {
3569                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3570                                         }
3571                                 }
3572                         }
3573                 }
3574
3575                 return $stack;
3576         }
3577
3578         /**
3579          * Get an associative array for selecting this title from
3580          * the "page" table
3581          *
3582          * @return Array suitable for the $where parameter of DB::select()
3583          */
3584         public function pageCond() {
3585                 if ( $this->mArticleID > 0 ) {
3586                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3587                         return array( 'page_id' => $this->mArticleID );
3588                 } else {
3589                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3590                 }
3591         }
3592
3593         /**
3594          * Get the revision ID of the previous revision
3595          *
3596          * @param $revId Int Revision ID. Get the revision that was before this one.
3597          * @param $flags Int Title::GAID_FOR_UPDATE
3598          * @return Int|Bool Old revision ID, or FALSE if none exists
3599          */
3600         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3601                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3602                 return $db->selectField( 'revision', 'rev_id',
3603                         array(
3604                                 'rev_page' => $this->getArticleId( $flags ),
3605                                 'rev_id < ' . intval( $revId )
3606                         ),
3607                         __METHOD__,
3608                         array( 'ORDER BY' => 'rev_id DESC' )
3609                 );
3610         }
3611
3612         /**
3613          * Get the revision ID of the next revision
3614          *
3615          * @param $revId Int Revision ID. Get the revision that was after this one.
3616          * @param $flags Int Title::GAID_FOR_UPDATE
3617          * @return Int|Bool Next revision ID, or FALSE if none exists
3618          */
3619         public function getNextRevisionID( $revId, $flags = 0 ) {
3620                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3621                 return $db->selectField( 'revision', 'rev_id',
3622                         array(
3623                                 'rev_page' => $this->getArticleId( $flags ),
3624                                 'rev_id > ' . intval( $revId )
3625                         ),
3626                         __METHOD__,
3627                         array( 'ORDER BY' => 'rev_id' )
3628                 );
3629         }
3630
3631         /**
3632          * Get the first revision of the page
3633          *
3634          * @param $flags Int Title::GAID_FOR_UPDATE
3635          * @return Revision|Null if page doesn't exist
3636          */
3637         public function getFirstRevision( $flags = 0 ) {
3638                 $pageId = $this->getArticleId( $flags );
3639                 if ( $pageId ) {
3640                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3641                         $row = $db->selectRow( 'revision', '*',
3642                                 array( 'rev_page' => $pageId ),
3643                                 __METHOD__,
3644                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3645                         );
3646                         if ( $row ) {
3647                                 return new Revision( $row );
3648                         }
3649                 }
3650                 return null;
3651         }
3652
3653         /**
3654          * Get the oldest revision timestamp of this page
3655          *
3656          * @param $flags Int Title::GAID_FOR_UPDATE
3657          * @return String: MW timestamp
3658          */
3659         public function getEarliestRevTime( $flags = 0 ) {
3660                 $rev = $this->getFirstRevision( $flags );
3661                 return $rev ? $rev->getTimestamp() : null;
3662         }
3663
3664         /**
3665          * Check if this is a new page
3666          *
3667          * @return bool
3668          */
3669         public function isNewPage() {
3670                 $dbr = wfGetDB( DB_SLAVE );
3671                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3672         }
3673
3674         /**
3675          * Get the number of revisions between the given revision.
3676          * Used for diffs and other things that really need it.
3677          *
3678          * @param $old int|Revision Old revision or rev ID (first before range)
3679          * @param $new int|Revision New revision or rev ID (first after range)
3680          * @return Int Number of revisions between these revisions.
3681          */
3682         public function countRevisionsBetween( $old, $new ) {
3683                 if ( !( $old instanceof Revision ) ) {
3684                         $old = Revision::newFromTitle( $this, (int)$old );
3685                 }
3686                 if ( !( $new instanceof Revision ) ) {
3687                         $new = Revision::newFromTitle( $this, (int)$new );
3688                 }
3689                 if ( !$old || !$new ) {
3690                         return 0; // nothing to compare
3691                 }
3692                 $dbr = wfGetDB( DB_SLAVE );
3693                 return (int)$dbr->selectField( 'revision', 'count(*)',
3694                         array(
3695                                 'rev_page' => $this->getArticleId(),
3696                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3697                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3698                         ),
3699                         __METHOD__
3700                 );
3701         }
3702
3703         /**
3704          * Get the number of authors between the given revision IDs.
3705          * Used for diffs and other things that really need it.
3706          *
3707          * @param $old int|Revision Old revision or rev ID (first before range)
3708          * @param $new int|Revision New revision or rev ID (first after range)
3709          * @param $limit Int Maximum number of authors
3710          * @return Int Number of revision authors between these revisions.
3711          */
3712         public function countAuthorsBetween( $old, $new, $limit ) {
3713                 if ( !( $old instanceof Revision ) ) {
3714                         $old = Revision::newFromTitle( $this, (int)$old );
3715                 }
3716                 if ( !( $new instanceof Revision ) ) {
3717                         $new = Revision::newFromTitle( $this, (int)$new );
3718                 }
3719                 if ( !$old || !$new ) {
3720                         return 0; // nothing to compare
3721                 }
3722                 $dbr = wfGetDB( DB_SLAVE );
3723                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
3724                         array(
3725                                 'rev_page' => $this->getArticleID(),
3726                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3727                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3728                         ), __METHOD__,
3729                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
3730                 );
3731                 return (int)$dbr->numRows( $res );
3732         }
3733
3734         /**
3735          * Compare with another title.
3736          *
3737          * @param $title Title
3738          * @return Bool
3739          */
3740         public function equals( Title $title ) {
3741                 // Note: === is necessary for proper matching of number-like titles.
3742                 return $this->getInterwiki() === $title->getInterwiki()
3743                         && $this->getNamespace() == $title->getNamespace()
3744                         && $this->getDBkey() === $title->getDBkey();
3745         }
3746
3747         /**
3748          * Callback for usort() to do title sorts by (namespace, title)
3749          *
3750          * @param $a Title
3751          * @param $b Title
3752          *
3753          * @return Integer: result of string comparison, or namespace comparison
3754          */
3755         public static function compare( $a, $b ) {
3756                 if ( $a->getNamespace() == $b->getNamespace() ) {
3757                         return strcmp( $a->getText(), $b->getText() );
3758                 } else {
3759                         return $a->getNamespace() - $b->getNamespace();
3760                 }
3761         }
3762
3763         /**
3764          * Return a string representation of this title
3765          *
3766          * @return String representation of this title
3767          */
3768         public function __toString() {
3769                 return $this->getPrefixedText();
3770         }
3771
3772         /**
3773          * Check if page exists.  For historical reasons, this function simply
3774          * checks for the existence of the title in the page table, and will
3775          * thus return false for interwiki links, special pages and the like.
3776          * If you want to know if a title can be meaningfully viewed, you should
3777          * probably call the isKnown() method instead.
3778          *
3779          * @return Bool
3780          */
3781         public function exists() {
3782                 return $this->getArticleId() != 0;
3783         }
3784
3785         /**
3786          * Should links to this title be shown as potentially viewable (i.e. as
3787          * "bluelinks"), even if there's no record by this title in the page
3788          * table?
3789          *
3790          * This function is semi-deprecated for public use, as well as somewhat
3791          * misleadingly named.  You probably just want to call isKnown(), which
3792          * calls this function internally.
3793          *
3794          * (ISSUE: Most of these checks are cheap, but the file existence check
3795          * can potentially be quite expensive.  Including it here fixes a lot of
3796          * existing code, but we might want to add an optional parameter to skip
3797          * it and any other expensive checks.)
3798          *
3799          * @return Bool
3800          */
3801         public function isAlwaysKnown() {
3802                 if ( $this->mInterwiki != '' ) {
3803                         return true;  // any interwiki link might be viewable, for all we know
3804                 }
3805                 switch( $this->mNamespace ) {
3806                         case NS_MEDIA:
3807                         case NS_FILE:
3808                                 // file exists, possibly in a foreign repo
3809                                 return (bool)wfFindFile( $this );
3810                         case NS_SPECIAL:
3811                                 // valid special page
3812                                 return SpecialPageFactory::exists( $this->getDBkey() );
3813                         case NS_MAIN:
3814                                 // selflink, possibly with fragment
3815                                 return $this->mDbkeyform == '';
3816                         case NS_MEDIAWIKI:
3817                                 // known system message
3818                                 return $this->getDefaultMessageText() !== false;
3819                         default:
3820                                 return false;
3821                 }
3822         }
3823
3824         /**
3825          * Does this title refer to a page that can (or might) be meaningfully
3826          * viewed?  In particular, this function may be used to determine if
3827          * links to the title should be rendered as "bluelinks" (as opposed to
3828          * "redlinks" to non-existent pages).
3829          *
3830          * @return Bool
3831          */
3832         public function isKnown() {
3833                 return $this->isAlwaysKnown() || $this->exists();
3834         }
3835
3836         /**
3837          * Does this page have source text?
3838          *
3839          * @return Boolean
3840          */
3841         public function hasSourceText() {
3842                 if ( $this->exists() ) {
3843                         return true;
3844                 }
3845
3846                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3847                         // If the page doesn't exist but is a known system message, default
3848                         // message content will be displayed, same for language subpages
3849                         return $this->getDefaultMessageText() !== false;
3850                 }
3851
3852                 return false;
3853         }
3854
3855         /**
3856          * Get the default message text or false if the message doesn't exist
3857          *
3858          * @return String or false
3859          */
3860         public function getDefaultMessageText() {
3861                 global $wgContLang;
3862
3863                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
3864                         return false;
3865                 }
3866
3867                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
3868                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
3869
3870                 if ( $message->exists() ) {
3871                         return $message->plain();
3872                 } else {
3873                         return false;
3874                 }
3875         }
3876
3877         /**
3878          * Is this in a namespace that allows actual pages?
3879          *
3880          * @return Bool
3881          * @internal note -- uses hardcoded namespace index instead of constants
3882          */
3883         public function canExist() {
3884                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3885         }
3886
3887         /**
3888          * Update page_touched timestamps and send squid purge messages for
3889          * pages linking to this title. May be sent to the job queue depending
3890          * on the number of links. Typically called on create and delete.
3891          */
3892         public function touchLinks() {
3893                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3894                 $u->doUpdate();
3895
3896                 if ( $this->getNamespace() == NS_CATEGORY ) {
3897                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3898                         $u->doUpdate();
3899                 }
3900         }
3901
3902         /**
3903          * Get the last touched timestamp
3904          *
3905          * @param $db DatabaseBase: optional db
3906          * @return String last-touched timestamp
3907          */
3908         public function getTouched( $db = null ) {
3909                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3910                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3911                 return $touched;
3912         }
3913
3914         /**
3915          * Get the timestamp when this page was updated since the user last saw it.
3916          *
3917          * @param $user User
3918          * @return String|Null
3919          */
3920         public function getNotificationTimestamp( $user = null ) {
3921                 global $wgUser, $wgShowUpdatedMarker;
3922                 // Assume current user if none given
3923                 if ( !$user ) {
3924                         $user = $wgUser;
3925                 }
3926                 // Check cache first
3927                 $uid = $user->getId();
3928                 // avoid isset here, as it'll return false for null entries
3929                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
3930                         return $this->mNotificationTimestamp[$uid];
3931                 }
3932                 if ( !$uid || !$wgShowUpdatedMarker ) {
3933                         return $this->mNotificationTimestamp[$uid] = false;
3934                 }
3935                 // Don't cache too much!
3936                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3937                         $this->mNotificationTimestamp = array();
3938                 }
3939                 $dbr = wfGetDB( DB_SLAVE );
3940                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3941                         'wl_notificationtimestamp',
3942                         array( 'wl_namespace' => $this->getNamespace(),
3943                                 'wl_title' => $this->getDBkey(),
3944                                 'wl_user' => $user->getId()
3945                         ),
3946                         __METHOD__
3947                 );
3948                 return $this->mNotificationTimestamp[$uid];
3949         }
3950
3951         /**
3952          * Get the trackback URL for this page
3953          *
3954          * @return String Trackback URL
3955          */
3956         public function trackbackURL() {
3957                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3958
3959                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3960                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3961         }
3962
3963         /**
3964          * Get the trackback RDF for this page
3965          *
3966          * @return String Trackback RDF
3967          */
3968         public function trackbackRDF() {
3969                 $url = htmlspecialchars( $this->getFullURL() );
3970                 $title = htmlspecialchars( $this->getText() );
3971                 $tburl = $this->trackbackURL();
3972
3973                 // Autodiscovery RDF is placed in comments so HTML validator
3974                 // won't barf. This is a rather icky workaround, but seems
3975                 // frequently used by this kind of RDF thingy.
3976                 //
3977                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3978                 return "<!--
3979 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3980                  xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3981                  xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3982 <rdf:Description
3983    rdf:about=\"$url\"
3984    dc:identifier=\"$url\"
3985    dc:title=\"$title\"
3986    trackback:ping=\"$tburl\" />
3987 </rdf:RDF>
3988 -->";
3989         }
3990
3991         /**
3992          * Generate strings used for xml 'id' names in monobook tabs
3993          *
3994          * @param $prepend string defaults to 'nstab-'
3995          * @return String XML 'id' name
3996          */
3997         public function getNamespaceKey( $prepend = 'nstab-' ) {
3998                 global $wgContLang;
3999                 // Gets the subject namespace if this title
4000                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4001                 // Checks if cononical namespace name exists for namespace
4002                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4003                         // Uses canonical namespace name
4004                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4005                 } else {
4006                         // Uses text of namespace
4007                         $namespaceKey = $this->getSubjectNsText();
4008                 }
4009                 // Makes namespace key lowercase
4010                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4011                 // Uses main
4012                 if ( $namespaceKey == '' ) {
4013                         $namespaceKey = 'main';
4014                 }
4015                 // Changes file to image for backwards compatibility
4016                 if ( $namespaceKey == 'file' ) {
4017                         $namespaceKey = 'image';
4018                 }
4019                 return $prepend . $namespaceKey;
4020         }
4021
4022         /**
4023          * Returns true if this is a special page.
4024          *
4025          * @return boolean
4026          */
4027         public function isSpecialPage() {
4028                 return $this->getNamespace() == NS_SPECIAL;
4029         }
4030
4031         /**
4032          * Returns true if this title resolves to the named special page
4033          *
4034          * @param $name String The special page name
4035          * @return boolean
4036          */
4037         public function isSpecial( $name ) {
4038                 if ( $this->getNamespace() == NS_SPECIAL ) {
4039                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
4040                         if ( $name == $thisName ) {
4041                                 return true;
4042                         }
4043                 }
4044                 return false;
4045         }
4046
4047         /**
4048          * If the Title refers to a special page alias which is not the local default, resolve
4049          * the alias, and localise the name as necessary.  Otherwise, return $this
4050          *
4051          * @return Title
4052          */
4053         public function fixSpecialName() {
4054                 if ( $this->getNamespace() == NS_SPECIAL ) {
4055                         list( $canonicalName, /*...*/ ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
4056                         if ( $canonicalName ) {
4057                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName );
4058                                 if ( $localName != $this->mDbkeyform ) {
4059                                         return Title::makeTitle( NS_SPECIAL, $localName );
4060                                 }
4061                         }
4062                 }
4063                 return $this;
4064         }
4065
4066         /**
4067          * Is this Title in a namespace which contains content?
4068          * In other words, is this a content page, for the purposes of calculating
4069          * statistics, etc?
4070          *
4071          * @return Boolean
4072          */
4073         public function isContentPage() {
4074                 return MWNamespace::isContent( $this->getNamespace() );
4075         }
4076
4077         /**
4078          * Get all extant redirects to this Title
4079          *
4080          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4081          * @return Array of Title redirects to this title
4082          */
4083         public function getRedirectsHere( $ns = null ) {
4084                 $redirs = array();
4085
4086                 $dbr = wfGetDB( DB_SLAVE );
4087                 $where = array(
4088                         'rd_namespace' => $this->getNamespace(),
4089                         'rd_title' => $this->getDBkey(),
4090                         'rd_from = page_id'
4091                 );
4092                 if ( !is_null( $ns ) ) {
4093                         $where['page_namespace'] = $ns;
4094                 }
4095
4096                 $res = $dbr->select(
4097                         array( 'redirect', 'page' ),
4098                         array( 'page_namespace', 'page_title' ),
4099                         $where,
4100                         __METHOD__
4101                 );
4102
4103                 foreach ( $res as $row ) {
4104                         $redirs[] = self::newFromRow( $row );
4105                 }
4106                 return $redirs;
4107         }
4108
4109         /**
4110          * Check if this Title is a valid redirect target
4111          *
4112          * @return Bool
4113          */
4114         public function isValidRedirectTarget() {
4115                 global $wgInvalidRedirectTargets;
4116
4117                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4118                 if ( $this->isSpecial( 'Userlogout' ) ) {
4119                         return false;
4120                 }
4121
4122                 foreach ( $wgInvalidRedirectTargets as $target ) {
4123                         if ( $this->isSpecial( $target ) ) {
4124                                 return false;
4125                         }
4126                 }
4127
4128                 return true;
4129         }
4130
4131         /**
4132          * Get a backlink cache object
4133          *
4134          * @return object BacklinkCache
4135          */
4136         function getBacklinkCache() {
4137                 if ( is_null( $this->mBacklinkCache ) ) {
4138                         $this->mBacklinkCache = new BacklinkCache( $this );
4139                 }
4140                 return $this->mBacklinkCache;
4141         }
4142
4143         /**
4144          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4145          *
4146          * @return Boolean
4147          */
4148         public function canUseNoindex() {
4149                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4150
4151                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4152                         ? $wgContentNamespaces
4153                         : $wgExemptFromUserRobotsControl;
4154
4155                 return !in_array( $this->mNamespace, $bannedNamespaces );
4156
4157         }
4158
4159         /**
4160          * Returns restriction types for the current Title
4161          *
4162          * @return array applicable restriction types
4163          */
4164         public function getRestrictionTypes() {
4165                 if ( $this->getNamespace() == NS_SPECIAL ) {
4166                         return array();
4167                 }
4168
4169                 $types = self::getFilteredRestrictionTypes( $this->exists() );
4170
4171                 if ( $this->getNamespace() != NS_FILE ) {
4172                         # Remove the upload restriction for non-file titles
4173                         $types = array_diff( $types, array( 'upload' ) );
4174                 }
4175
4176                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4177
4178                 wfDebug( __METHOD__ . ': applicable restriction types for ' .
4179                         $this->getPrefixedText() . ' are ' . implode( ',', $types ) . "\n" );
4180
4181                 return $types;
4182         }
4183         /**
4184          * Get a filtered list of all restriction types supported by this wiki.
4185          * @param bool $exists True to get all restriction types that apply to
4186          * titles that do exist, False for all restriction types that apply to
4187          * titles that do not exist
4188          * @return array
4189          */
4190         public static function getFilteredRestrictionTypes( $exists = true ) {
4191                 global $wgRestrictionTypes;
4192                 $types = $wgRestrictionTypes;
4193                 if ( $exists ) {
4194                         # Remove the create restriction for existing titles
4195                         $types = array_diff( $types, array( 'create' ) );
4196                 } else {
4197                         # Only the create and upload restrictions apply to non-existing titles
4198                         $types = array_intersect( $types, array( 'create', 'upload' ) );
4199                 }
4200                 return $types;
4201         }
4202
4203         /**
4204          * Returns the raw sort key to be used for categories, with the specified
4205          * prefix.  This will be fed to Collation::getSortKey() to get a
4206          * binary sortkey that can be used for actual sorting.
4207          *
4208          * @param $prefix string The prefix to be used, specified using
4209          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4210          *   prefix.
4211          * @return string
4212          */
4213         public function getCategorySortkey( $prefix = '' ) {
4214                 $unprefixed = $this->getText();
4215                 if ( $prefix !== '' ) {
4216                         # Separate with a line feed, so the unprefixed part is only used as
4217                         # a tiebreaker when two pages have the exact same prefix.
4218                         # In UCA, tab is the only character that can sort above LF
4219                         # so we strip both of them from the original prefix.
4220                         $prefix = strtr( $prefix, "\n\t", '  ' );
4221                         return "$prefix\n$unprefixed";
4222                 }
4223                 return $unprefixed;
4224         }
4225
4226         /**
4227          * Get the language this page is written in
4228          * Defaults to $wgContLang
4229          *
4230          * @return object Language
4231          */
4232         public function getPageLanguage() {
4233                 global $wgContLang;
4234                 $this->mPageLanguage = $wgContLang;
4235                 if ( $this->isCssOrJsPage() ) {
4236                         // css/js should always be LTR and is, in fact, English
4237                         $this->mPageLanguage = Language::factory( 'en' );
4238                 } elseif ( $this->getNamespace() == NS_MEDIAWIKI ) {
4239                         // Parse mediawiki messages with correct target language
4240                         list( /* $unused */, $lang ) = MessageCache::singleton()->figureMessage( $this->getText() );
4241                         $this->mPageLanguage = wfGetLangObj( $lang );
4242                 }
4243                 return $this->mPageLanguage;
4244         }
4245 }
4246
4247 /**
4248  * A BadTitle is generated in MediaWiki::parseTitle() if the title is invalid; the
4249  * software uses this to display an error page.  Internally it's basically a Title
4250  * for an empty special page
4251  */
4252 class BadTitle extends Title {
4253         public function __construct(){
4254                 $this->mTextform = '';
4255                 $this->mUrlform = '';
4256                 $this->mDbkeyform = '';
4257                 $this->mNamespace = NS_SPECIAL; // Stops talk page link, etc, being shown
4258         }
4259
4260         public function exists(){
4261                 return false;
4262         }
4263
4264         public function getPrefixedText(){
4265                 return '';
4266         }
4267
4268         public function getText(){
4269                 return '';
4270         }
4271
4272         public function getPrefixedURL(){
4273                 return '';
4274         }
4275
4276         public function getPrefixedDBKey(){
4277                 return '';
4278         }
4279 }