includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  * @file
   5  */
   6
   7 /**
   8  * Represents a title within MediaWiki.
   9  * Optionally may contain an interwiki designation or namespace.
  10  * @note This class can fetch various kinds of data from the database;
  11  *       however, it does so inefficiently.
  12  *
  13  * @internal documentation reviewed 15 Mar 2010
  14  */
  15 class Title {
  16         /** @name Static cache variables */
  17         // @{
  18         static private $titleCache = array();
  19         // @}
  20
  21         /**
  22          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  23          * commonly used titles. On a batch operation this can become a memory leak
  24          * if not bounded. After hitting this many titles reset the cache.
  25          */
  26         const CACHE_MAX = 1000;
  27
  28         /**
  29          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  30          * to use the master DB
  31          */
  32         const GAID_FOR_UPDATE = 1;
  33
  34
  35         /**
  36          * @name Private member variables
  37          * Please use the accessor functions instead.
  38          * @private
  39          */
  40         // @{
  41
  42         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  43         var $mUrlform = '';               // /< URL-encoded form of the main part
  44         var $mDbkeyform = '';             // /< Main part with underscores
  45         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  46         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  47         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  48         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  49         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  50         var $mLatestID = false;           // /< ID of most recent revision
  51         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  52         var $mOldRestrictions = false;
  53         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  54         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  55         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  56         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  57         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  58         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  59         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  60         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  61         # Don't change the following default, NS_MAIN is hardcoded in several
  62         # places.  See bug 696.
  63         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  64                                                                           # Zero except in {{transclusion}} tags
  65         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  66         var $mLength = -1;                // /< The page length, 0 for special pages
  67         var $mRedirect = null;            // /< Is the article at this title a redirect?
  68         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  69         var $mBacklinkCache = null;       // /< Cache of links to this title
  70         // @}
  71
  72
  73         /**
  74          * Constructor
  75          */
  76         /*protected*/ function __construct() { }
  77
  78         /**
  79          * Create a new Title from a prefixed DB key
  80          *
  81          * @param $key String the database key, which has underscores
  82          *      instead of spaces, possibly including namespace and
  83          *      interwiki prefixes
  84          * @return Title, or NULL on an error
  85          */
  86         public static function newFromDBkey( $key ) {
  87                 $t = new Title();
  88                 $t->mDbkeyform = $key;
  89                 if ( $t->secureAndSplit() ) {
  90                         return $t;
  91                 } else {
  92                         return null;
  93                 }
  94         }
  95
  96         /**
  97          * Create a new Title from text, such as what one would find in a link. De-
  98          * codes any HTML entities in the text.
  99          *
 100          * @param $text String the link text; spaces, prefixes, and an
 101          *   initial ':' indicating the main namespace are accepted.
 102          * @param $defaultNamespace Int the namespace to use if none is speci-
 103          *   fied by a prefix.  If you want to force a specific namespace even if
 104          *   $text might begin with a namespace prefix, use makeTitle() or
 105          *   makeTitleSafe().
 106          * @return Title, or null on an error.
 107          */
 108         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 109                 if ( is_object( $text ) ) {
 110                         throw new MWException( 'Title::newFromText given an object' );
 111                 }
 112
 113                 /**
 114                  * Wiki pages often contain multiple links to the same page.
 115                  * Title normalization and parsing can become expensive on
 116                  * pages with many links, so we can save a little time by
 117                  * caching them.
 118                  *
 119                  * In theory these are value objects and won't get changed...
 120                  */
 121                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 122                         return Title::$titleCache[$text];
 123                 }
 124
 125                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 126                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 127
 128                 $t = new Title();
 129                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 130                 $t->mDefaultNamespace = $defaultNamespace;
 131
 132                 static $cachedcount = 0 ;
 133                 if ( $t->secureAndSplit() ) {
 134                         if ( $defaultNamespace == NS_MAIN ) {
 135                                 if ( $cachedcount >= self::CACHE_MAX ) {
 136                                         # Avoid memory leaks on mass operations...
 137                                         Title::$titleCache = array();
 138                                         $cachedcount = 0;
 139                                 }
 140                                 $cachedcount++;
 141                                 Title::$titleCache[$text] =& $t;
 142                         }
 143                         return $t;
 144                 } else {
 145                         $ret = null;
 146                         return $ret;
 147                 }
 148         }
 149
 150         /**
 151          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 152          *
 153          * Example of wrong and broken code:
 154          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 155          *
 156          * Example of right code:
 157          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 158          *
 159          * Create a new Title from URL-encoded text. Ensures that
 160          * the given title's length does not exceed the maximum.
 161          *
 162          * @param $url String the title, as might be taken from a URL
 163          * @return Title the new object, or NULL on an error
 164          */
 165         public static function newFromURL( $url ) {
 166                 global $wgLegalTitleChars;
 167                 $t = new Title();
 168
 169                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 170                 # but some URLs used it as a space replacement and they still come
 171                 # from some external search tools.
 172                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 173                         $url = str_replace( '+', ' ', $url );
 174                 }
 175
 176                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 177                 if ( $t->secureAndSplit() ) {
 178                         return $t;
 179                 } else {
 180                         return null;
 181                 }
 182         }
 183
 184         /**
 185          * Create a new Title from an article ID
 186          *
 187          * @param $id Int the page_id corresponding to the Title to create
 188          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 189          * @return Title the new object, or NULL on an error
 190          */
 191         public static function newFromID( $id, $flags = 0 ) {
 192                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 193                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 194                 if ( $row !== false ) {
 195                         $title = Title::newFromRow( $row );
 196                 } else {
 197                         $title = null;
 198                 }
 199                 return $title;
 200         }
 201
 202         /**
 203          * Make an array of titles from an array of IDs
 204          *
 205          * @param $ids Array of Int Array of IDs
 206          * @return Array of Titles
 207          */
 208         public static function newFromIDs( $ids ) {
 209                 if ( !count( $ids ) ) {
 210                         return array();
 211                 }
 212                 $dbr = wfGetDB( DB_SLAVE );
 213
 214                 $res = $dbr->select(
 215                         'page',
 216                         array(
 217                                 'page_namespace', 'page_title', 'page_id',
 218                                 'page_len', 'page_is_redirect', 'page_latest',
 219                         ),
 220                         array( 'page_id' => $ids ),
 221                         __METHOD__
 222                 );
 223
 224                 $titles = array();
 225                 foreach ( $res as $row ) {
 226                         $titles[] = Title::newFromRow( $row );
 227                 }
 228                 return $titles;
 229         }
 230
 231         /**
 232          * Make a Title object from a DB row
 233          *
 234          * @param $row Object database row (needs at least page_title,page_namespace)
 235          * @return Title corresponding Title
 236          */
 237         public static function newFromRow( $row ) {
 238                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 239
 240                 $t->mArticleID = isset( $row->page_id ) ? intval( $row->page_id ) : -1;
 241                 $t->mLength = isset( $row->page_len ) ? intval( $row->page_len ) : -1;
 242                 $t->mRedirect = isset( $row->page_is_redirect ) ? (bool)$row->page_is_redirect : null;
 243                 $t->mLatestID = isset( $row->page_latest ) ? intval( $row->page_latest ) : false;
 244
 245                 return $t;
 246         }
 247
 248         /**
 249          * Create a new Title from a namespace index and a DB key.
 250          * It's assumed that $ns and $title are *valid*, for instance when
 251          * they came directly from the database or a special page name.
 252          * For convenience, spaces are converted to underscores so that
 253          * eg user_text fields can be used directly.
 254          *
 255          * @param $ns Int the namespace of the article
 256          * @param $title String the unprefixed database key form
 257          * @param $fragment String the link fragment (after the "#")
 258          * @param $interwiki String the interwiki prefix
 259          * @return Title the new object
 260          */
 261         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 262                 $t = new Title();
 263                 $t->mInterwiki = $interwiki;
 264                 $t->mFragment = $fragment;
 265                 $t->mNamespace = $ns = intval( $ns );
 266                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 267                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 268                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 269                 $t->mTextform = str_replace( '_', ' ', $title );
 270                 return $t;
 271         }
 272
 273         /**
 274          * Create a new Title from a namespace index and a DB key.
 275          * The parameters will be checked for validity, which is a bit slower
 276          * than makeTitle() but safer for user-provided data.
 277          *
 278          * @param $ns Int the namespace of the article
 279          * @param $title String database key form
 280          * @param $fragment String the link fragment (after the "#")
 281          * @param $interwiki String interwiki prefix
 282          * @return Title the new object, or NULL on an error
 283          */
 284         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 285                 $t = new Title();
 286                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 287                 if ( $t->secureAndSplit() ) {
 288                         return $t;
 289                 } else {
 290                         return null;
 291                 }
 292         }
 293
 294         /**
 295          * Create a new Title for the Main Page
 296          *
 297          * @return Title the new object
 298          */
 299         public static function newMainPage() {
 300                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 301                 // Don't give fatal errors if the message is broken
 302                 if ( !$title ) {
 303                         $title = Title::newFromText( 'Main Page' );
 304                 }
 305                 return $title;
 306         }
 307
 308         /**
 309          * Extract a redirect destination from a string and return the
 310          * Title, or null if the text doesn't contain a valid redirect
 311          * This will only return the very next target, useful for
 312          * the redirect table and other checks that don't need full recursion
 313          *
 314          * @param $text String: Text with possible redirect
 315          * @return Title: The corresponding Title
 316          */
 317         public static function newFromRedirect( $text ) {
 318                 return self::newFromRedirectInternal( $text );
 319         }
 320
 321         /**
 322          * Extract a redirect destination from a string and return the
 323          * Title, or null if the text doesn't contain a valid redirect
 324          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 325          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 326          *
 327          * @param $text String Text with possible redirect
 328          * @return Title
 329          */
 330         public static function newFromRedirectRecurse( $text ) {
 331                 $titles = self::newFromRedirectArray( $text );
 332                 return $titles ? array_pop( $titles ) : null;
 333         }
 334
 335         /**
 336          * Extract a redirect destination from a string and return an
 337          * array of Titles, or null if the text doesn't contain a valid redirect
 338          * The last element in the array is the final destination after all redirects
 339          * have been resolved (up to $wgMaxRedirects times)
 340          *
 341          * @param $text String Text with possible redirect
 342          * @return Array of Titles, with the destination last
 343          */
 344         public static function newFromRedirectArray( $text ) {
 345                 global $wgMaxRedirects;
 346                 $title = self::newFromRedirectInternal( $text );
 347                 if ( is_null( $title ) ) {
 348                         return null;
 349                 }
 350                 // recursive check to follow double redirects
 351                 $recurse = $wgMaxRedirects;
 352                 $titles = array( $title );
 353                 while ( --$recurse > 0 ) {
 354                         if ( $title->isRedirect() ) {
 355                                 $article = new Article( $title, 0 );
 356                                 $newtitle = $article->getRedirectTarget();
 357                         } else {
 358                                 break;
 359                         }
 360                         // Redirects to some special pages are not permitted
 361                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 362                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 363                                 $title = $newtitle;
 364                                 $titles[] = $newtitle;
 365                         } else {
 366                                 break;
 367                         }
 368                 }
 369                 return $titles;
 370         }
 371
 372         /**
 373          * Really extract the redirect destination
 374          * Do not call this function directly, use one of the newFromRedirect* functions above
 375          *
 376          * @param $text String Text with possible redirect
 377          * @return Title
 378          */
 379         protected static function newFromRedirectInternal( $text ) {
 380                 global $wgMaxRedirects;
 381                 if ( $wgMaxRedirects < 1 ) {
 382                         //redirects are disabled, so quit early
 383                         return null;
 384                 }
 385                 $redir = MagicWord::get( 'redirect' );
 386                 $text = trim( $text );
 387                 if ( $redir->matchStartAndRemove( $text ) ) {
 388                         // Extract the first link and see if it's usable
 389                         // Ensure that it really does come directly after #REDIRECT
 390                         // Some older redirects included a colon, so don't freak about that!
 391                         $m = array();
 392                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 393                                 // Strip preceding colon used to "escape" categories, etc.
 394                                 // and URL-decode links
 395                                 if ( strpos( $m[1], '%' ) !== false ) {
 396                                         // Match behavior of inline link parsing here;
 397                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 398                                 }
 399                                 $title = Title::newFromText( $m[1] );
 400                                 // If the title is a redirect to bad special pages or is invalid, return null
 401                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 402                                         return null;
 403                                 }
 404                                 return $title;
 405                         }
 406                 }
 407                 return null;
 408         }
 409
 410 # ----------------------------------------------------------------------------
 411 #       Static functions
 412 # ----------------------------------------------------------------------------
 413
 414         /**
 415          * Get the prefixed DB key associated with an ID
 416          *
 417          * @param $id Int the page_id of the article
 418          * @return Title an object representing the article, or NULL if no such article was found
 419          */
 420         public static function nameOf( $id ) {
 421                 $dbr = wfGetDB( DB_SLAVE );
 422
 423                 $s = $dbr->selectRow(
 424                         'page',
 425                         array( 'page_namespace', 'page_title' ),
 426                         array( 'page_id' => $id ),
 427                         __METHOD__
 428                 );
 429                 if ( $s === false ) {
 430                         return null;
 431                 }
 432
 433                 $n = self::makeName( $s->page_namespace, $s->page_title );
 434                 return $n;
 435         }
 436
 437         /**
 438          * Get a regex character class describing the legal characters in a link
 439          *
 440          * @return String the list of characters, not delimited
 441          */
 442         public static function legalChars() {
 443                 global $wgLegalTitleChars;
 444                 return $wgLegalTitleChars;
 445         }
 446
 447         /**
 448          * Get a string representation of a title suitable for
 449          * including in a search index
 450          *
 451          * @param $ns Int a namespace index
 452          * @param $title String text-form main part
 453          * @return String a stripped-down title string ready for the search index
 454          */
 455         public static function indexTitle( $ns, $title ) {
 456                 global $wgContLang;
 457
 458                 $lc = SearchEngine::legalSearchChars() . '&#;';
 459                 $t = $wgContLang->normalizeForSearch( $title );
 460                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 461                 $t = $wgContLang->lc( $t );
 462
 463                 # Handle 's, s'
 464                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 465                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 466
 467                 $t = preg_replace( "/\\s+/", ' ', $t );
 468
 469                 if ( $ns == NS_FILE ) {
 470                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 471                 }
 472                 return trim( $t );
 473         }
 474
 475         /**
 476          * Make a prefixed DB key from a DB key and a namespace index
 477          *
 478          * @param $ns Int numerical representation of the namespace
 479          * @param $title String the DB key form the title
 480          * @param $fragment String The link fragment (after the "#")
 481          * @param $interwiki String The interwiki prefix
 482          * @return String the prefixed form of the title
 483          */
 484         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 485                 global $wgContLang;
 486
 487                 $namespace = $wgContLang->getNsText( $ns );
 488                 $name = $namespace == '' ? $title : "$namespace:$title";
 489                 if ( strval( $interwiki ) != '' ) {
 490                         $name = "$interwiki:$name";
 491                 }
 492                 if ( strval( $fragment ) != '' ) {
 493                         $name .= '#' . $fragment;
 494                 }
 495                 return $name;
 496         }
 497
 498         /**
 499          * Determine whether the object refers to a page within
 500          * this project.
 501          *
 502          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 503          */
 504         public function isLocal() {
 505                 if ( $this->mInterwiki != '' ) {
 506                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 507                 } else {
 508                         return true;
 509                 }
 510         }
 511
 512         /**
 513          * Determine whether the object refers to a page within
 514          * this project and is transcludable.
 515          *
 516          * @return Bool TRUE if this is transcludable
 517          */
 518         public function isTrans() {
 519                 if ( $this->mInterwiki == '' ) {
 520                         return false;
 521                 }
 522
 523                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 524         }
 525
 526         /**
 527          * Returns the DB name of the distant wiki which owns the object.
 528          *
 529          * @return String the DB name
 530          */
 531         public function getTransWikiID() {
 532                 if ( $this->mInterwiki == '' ) {
 533                         return false;
 534                 }
 535
 536                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 537         }
 538
 539         /**
 540          * Escape a text fragment, say from a link, for a URL
 541          *
 542          * @param $fragment string containing a URL or link fragment (after the "#")
 543          * @return String: escaped string
 544          */
 545         static function escapeFragmentForURL( $fragment ) {
 546                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 547                 # fragments appear not to work in IE (at least up to 7) or in at least
 548                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 549                 # to care if they aren't encoded.
 550                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 551         }
 552
 553 # ----------------------------------------------------------------------------
 554 #       Other stuff
 555 # ----------------------------------------------------------------------------
 556
 557         /** Simple accessors */
 558         /**
 559          * Get the text form (spaces not underscores) of the main part
 560          *
 561          * @return String Main part of the title
 562          */
 563         public function getText() { return $this->mTextform; }
 564
 565         /**
 566          * Get the URL-encoded form of the main part
 567          *
 568          * @return String Main part of the title, URL-encoded
 569          */
 570         public function getPartialURL() { return $this->mUrlform; }
 571
 572         /**
 573          * Get the main part with underscores
 574          *
 575          * @return String: Main part of the title, with underscores
 576          */
 577         public function getDBkey() { return $this->mDbkeyform; }
 578
 579         /**
 580          * Get the namespace index, i.e. one of the NS_xxxx constants.
 581          *
 582          * @return Integer: Namespace index
 583          */
 584         public function getNamespace() { return $this->mNamespace; }
 585
 586         /**
 587          * Get the namespace text
 588          *
 589          * @return String: Namespace text
 590          */
 591         public function getNsText() {
 592                 global $wgContLang;
 593
 594                 if ( $this->mInterwiki != '' ) {
 595                         // This probably shouldn't even happen. ohh man, oh yuck.
 596                         // But for interwiki transclusion it sometimes does.
 597                         // Shit. Shit shit shit.
 598                         //
 599                         // Use the canonical namespaces if possible to try to
 600                         // resolve a foreign namespace.
 601                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 602                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 603                         }
 604                 }
 605
 606                 if ( $wgContLang->needsGenderDistinction() &&
 607                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 608                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 609                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 610                 }
 611
 612                 return $wgContLang->getNsText( $this->mNamespace );
 613         }
 614
 615         /**
 616          * Get the DB key with the initial letter case as specified by the user
 617          *
 618          * @return String DB key
 619          */
 620         function getUserCaseDBKey() {
 621                 return $this->mUserCaseDBKey;
 622         }
 623
 624         /**
 625          * Get the namespace text of the subject (rather than talk) page
 626          *
 627          * @return String Namespace text
 628          */
 629         public function getSubjectNsText() {
 630                 global $wgContLang;
 631                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 632         }
 633
 634         /**
 635          * Get the namespace text of the talk page
 636          *
 637          * @return String Namespace text
 638          */
 639         public function getTalkNsText() {
 640                 global $wgContLang;
 641                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 642         }
 643
 644         /**
 645          * Could this title have a corresponding talk page?
 646          *
 647          * @return Bool TRUE or FALSE
 648          */
 649         public function canTalk() {
 650                 return( MWNamespace::canTalk( $this->mNamespace ) );
 651         }
 652
 653         /**
 654          * Get the interwiki prefix (or null string)
 655          *
 656          * @return String Interwiki prefix
 657          */
 658         public function getInterwiki() { return $this->mInterwiki; }
 659
 660         /**
 661          * Get the Title fragment (i.e.\ the bit after the #) in text form
 662          *
 663          * @return String Title fragment
 664          */
 665         public function getFragment() { return $this->mFragment; }
 666
 667         /**
 668          * Get the fragment in URL form, including the "#" character if there is one
 669          * @return String Fragment in URL form
 670          */
 671         public function getFragmentForURL() {
 672                 if ( $this->mFragment == '' ) {
 673                         return '';
 674                 } else {
 675                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 676                 }
 677         }
 678
 679         /**
 680          * Get the default namespace index, for when there is no namespace
 681          *
 682          * @return Int Default namespace index
 683          */
 684         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 685
 686         /**
 687          * Get title for search index
 688          *
 689          * @return String a stripped-down title string ready for the
 690          *  search index
 691          */
 692         public function getIndexTitle() {
 693                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 694         }
 695
 696         /**
 697          * Get the prefixed database key form
 698          *
 699          * @return String the prefixed title, with underscores and
 700          *  any interwiki and namespace prefixes
 701          */
 702         public function getPrefixedDBkey() {
 703                 $s = $this->prefix( $this->mDbkeyform );
 704                 $s = str_replace( ' ', '_', $s );
 705                 return $s;
 706         }
 707
 708         /**
 709          * Get the prefixed title with spaces.
 710          * This is the form usually used for display
 711          *
 712          * @return String the prefixed title, with spaces
 713          */
 714         public function getPrefixedText() {
 715                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 716                         $s = $this->prefix( $this->mTextform );
 717                         $s = str_replace( '_', ' ', $s );
 718                         $this->mPrefixedText = $s;
 719                 }
 720                 return $this->mPrefixedText;
 721         }
 722
 723         /**
 724          * Get the prefixed title with spaces, plus any fragment
 725          * (part beginning with '#')
 726          *
 727          * @return String the prefixed title, with spaces and the fragment, including '#'
 728          */
 729         public function getFullText() {
 730                 $text = $this->getPrefixedText();
 731                 if ( $this->mFragment != '' ) {
 732                         $text .= '#' . $this->mFragment;
 733                 }
 734                 return $text;
 735         }
 736
 737         /**
 738          * Get the base name, i.e. the leftmost parts before the /
 739          *
 740          * @return String Base name
 741          */
 742         public function getBaseText() {
 743                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 744                         return $this->getText();
 745                 }
 746
 747                 $parts = explode( '/', $this->getText() );
 748                 # Don't discard the real title if there's no subpage involved
 749                 if ( count( $parts ) > 1 ) {
 750                         unset( $parts[count( $parts ) - 1] );
 751                 }
 752                 return implode( '/', $parts );
 753         }
 754
 755         /**
 756          * Get the lowest-level subpage name, i.e. the rightmost part after /
 757          *
 758          * @return String Subpage name
 759          */
 760         public function getSubpageText() {
 761                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 762                         return( $this->mTextform );
 763                 }
 764                 $parts = explode( '/', $this->mTextform );
 765                 return( $parts[count( $parts ) - 1] );
 766         }
 767
 768         /**
 769          * Get a URL-encoded form of the subpage text
 770          *
 771          * @return String URL-encoded subpage name
 772          */
 773         public function getSubpageUrlForm() {
 774                 $text = $this->getSubpageText();
 775                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 776                 return( $text );
 777         }
 778
 779         /**
 780          * Get a URL-encoded title (not an actual URL) including interwiki
 781          *
 782          * @return String the URL-encoded form
 783          */
 784         public function getPrefixedURL() {
 785                 $s = $this->prefix( $this->mDbkeyform );
 786                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 787                 return $s;
 788         }
 789
 790         /**
 791          * Get a real URL referring to this title, with interwiki link and
 792          * fragment
 793          *
 794          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 795          *   links. Can be specified as an associative array as well, e.g.,
 796          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 797          * @param $variant String language variant of url (for sr, zh..)
 798          * @return String the URL
 799          */
 800         public function getFullURL( $query = '', $variant = false ) {
 801                 global $wgServer, $wgRequest;
 802
 803                 if ( is_array( $query ) ) {
 804                         $query = wfArrayToCGI( $query );
 805                 }
 806
 807                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 808                 if ( !$interwiki ) {
 809                         $url = $this->getLocalURL( $query, $variant );
 810
 811                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 812                         // Correct fix would be to move the prepending elsewhere.
 813                         if ( $wgRequest->getVal( 'action' ) != 'render' ) {
 814                                 $url = $wgServer . $url;
 815                         }
 816                 } else {
 817                         $baseUrl = $interwiki->getURL();
 818
 819                         $namespace = wfUrlencode( $this->getNsText() );
 820                         if ( $namespace != '' ) {
 821                                 # Can this actually happen? Interwikis shouldn't be parsed.
 822                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 823                                 $namespace .= ':';
 824                         }
 825                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 826                         $url = wfAppendQuery( $url, $query );
 827                 }
 828
 829                 # Finally, add the fragment.
 830                 $url .= $this->getFragmentForURL();
 831
 832                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 833                 return $url;
 834         }
 835
 836         /**
 837          * Get a URL with no fragment or server name.  If this page is generated
 838          * with action=render, $wgServer is prepended.
 839          *
 840          * @param $query Mixed: an optional query string; if not specified,
 841          *   $wgArticlePath will be used.  Can be specified as an associative array
 842          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 843          *   URL-escaped).
 844          * @param $variant String language variant of url (for sr, zh..)
 845          * @return String the URL
 846          */
 847         public function getLocalURL( $query = '', $variant = false ) {
 848                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 849                 global $wgVariantArticlePath, $wgContLang;
 850
 851                 if ( is_array( $query ) ) {
 852                         $query = wfArrayToCGI( $query );
 853                 }
 854
 855                 if ( $this->isExternal() ) {
 856                         $url = $this->getFullURL();
 857                         if ( $query ) {
 858                                 // This is currently only used for edit section links in the
 859                                 // context of interwiki transclusion. In theory we should
 860                                 // append the query to the end of any existing query string,
 861                                 // but interwiki transclusion is already broken in that case.
 862                                 $url .= "?$query";
 863                         }
 864                 } else {
 865                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 866                         if ( $query == '' ) {
 867                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 868                                         if ( !$wgVariantArticlePath ) {
 869                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 870                                         } else {
 871                                                 $variantArticlePath = $wgVariantArticlePath;
 872                                         }
 873                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 874                                         $url = str_replace( '$1', $dbkey, $url  );
 875                                 } else {
 876                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 877                                 }
 878                         } else {
 879                                 $url = false;
 880
 881                                 global $wgActionPaths;
 882                                 if( !empty( $wgActionPaths ) ) {
 883                                         $url = Title::resolveActionPath( $dbkey, $query );
 884                                 }
 885
 886                                 if ( $url === false ) {
 887                                         if ( $query == '-' ) {
 888                                                 $query = '';
 889                                         }
 890                                         #$url = "{$wgScript}?title={$dbkey}&{$query}";
 891                                         # forge a nice URL (ex: /wiki/Special:Foo?q=1&r=2 )
 892                                         $baseurl = str_replace( '$1', $dbkey, $wgArticlePath );
 893                                         $url = wfAppendQuery( $baseurl, $query );
 894                                 }
 895                         }
 896
 897                         // FIXME: this causes breakage in various places when we
 898                         // actually expected a local URL and end up with dupe prefixes.
 899                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 900                                 $url = $wgServer . $url;
 901                         }
 902                 }
 903                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 904                 return $url;
 905         }
 906
 907         /**
 908          * Helper for getLocalUrl() to handles $wgActionPaths
 909          *
 910          * @param $dbkey string Title in database key format
 911          * @param $query string request parameters in CGI format (p=1&q=2&..)
 912          * @return Url resolved or boolean false
 913          */
 914         private static function resolveActionPath( $dbkey, $query ) {
 915                 $url = '';
 916
 917                 # query parameters are easier to handle using an array:
 918                 $queryArray = wfCGIToArray( $query );
 919
 920                 global $wgActionPaths;
 921                 if( !array_key_exists( 'action', $queryArray ) ) {
 922                         // Makes the default action 'view' and points to $wgArticlePath
 923                         // FIXME: this should be handled in Setup or Wiki!
 924                         global $wgArticlePath;
 925                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 926                 } elseif( isset( $wgActionPaths[$queryArray['action']] ) ) {
 927                         $url = str_replace( '$1', $dbkey, $wgActionPaths[$queryArray['action']] );
 928                 } else {
 929                         # No path found
 930                         return false;
 931                 }
 932
 933                 # No need to append the action since we have embed it in the path
 934                 unset( $queryArray['action'] );
 935                 $url = wfAppendQuery( $url, wfArrayToCGI( $queryArray ) );
 936                 return $url;
 937         }
 938
 939         /**
 940          * Get a URL that's the simplest URL that will be valid to link, locally,
 941          * to the current Title.  It includes the fragment, but does not include
 942          * the server unless action=render is used (or the link is external).  If
 943          * there's a fragment but the prefixed text is empty, we just return a link
 944          * to the fragment.
 945          *
 946          * The result obviously should not be URL-escaped, but does need to be
 947          * HTML-escaped if it's being output in HTML.
 948          *
 949          * @param $query Array of Strings An associative array of key => value pairs for the
 950          *   query string.  Keys and values will be escaped.
 951          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 952          *   for external links.  Default is "false" (same variant as current page,
 953          *   for anonymous users).
 954          * @return String the URL
 955          */
 956         public function getLinkUrl( $query = array(), $variant = false ) {
 957                 wfProfileIn( __METHOD__ );
 958                 if ( $this->isExternal() ) {
 959                         $ret = $this->getFullURL( $query );
 960                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 961                         $ret = $this->getFragmentForURL();
 962                 } else {
 963                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 964                 }
 965                 wfProfileOut( __METHOD__ );
 966                 return $ret;
 967         }
 968
 969         /**
 970          * Get an HTML-escaped version of the URL form, suitable for
 971          * using in a link, without a server name or fragment
 972          *
 973          * @param $query String an optional query string
 974          * @return String the URL
 975          */
 976         public function escapeLocalURL( $query = '' ) {
 977                 return htmlspecialchars( $this->getLocalURL( $query ) );
 978         }
 979
 980         /**
 981          * Get an HTML-escaped version of the URL form, suitable for
 982          * using in a link, including the server name and fragment
 983          *
 984          * @param $query String an optional query string
 985          * @return String the URL
 986          */
 987         public function escapeFullURL( $query = '' ) {
 988                 return htmlspecialchars( $this->getFullURL( $query ) );
 989         }
 990
 991         /**
 992          * Get the URL form for an internal link.
 993          * - Used in various Squid-related code, in case we have a different
 994          * internal hostname for the server from the exposed one.
 995          *
 996          * @param $query String an optional query string
 997          * @param $variant String language variant of url (for sr, zh..)
 998          * @return String the URL
 999          */
1000         public function getInternalURL( $query = '', $variant = false ) {
1001                 global $wgInternalServer, $wgServer;
1002                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1003                 $url = $server . $this->getLocalURL( $query, $variant );
1004                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1005                 return $url;
1006         }
1007
1008         /**
1009          * Get the edit URL for this Title
1010          *
1011          * @return String the URL, or a null string if this is an
1012          *  interwiki link
1013          */
1014         public function getEditURL() {
1015                 if ( $this->mInterwiki != '' ) {
1016                         return '';
1017                 }
1018                 $s = $this->getLocalURL( 'action=edit' );
1019
1020                 return $s;
1021         }
1022
1023         /**
1024          * Get the HTML-escaped displayable text form.
1025          * Used for the title field in <a> tags.
1026          *
1027          * @return String the text, including any prefixes
1028          */
1029         public function getEscapedText() {
1030                 return htmlspecialchars( $this->getPrefixedText() );
1031         }
1032
1033         /**
1034          * Is this Title interwiki?
1035          *
1036          * @return Bool
1037          */
1038         public function isExternal() {
1039                 return ( $this->mInterwiki != '' );
1040         }
1041
1042         /**
1043          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1044          *
1045          * @param $action String Action to check (default: edit)
1046          * @return Bool
1047          */
1048         public function isSemiProtected( $action = 'edit' ) {
1049                 if ( $this->exists() ) {
1050                         $restrictions = $this->getRestrictions( $action );
1051                         if ( count( $restrictions ) > 0 ) {
1052                                 foreach ( $restrictions as $restriction ) {
1053                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1054                                                 return false;
1055                                         }
1056                                 }
1057                         } else {
1058                                 # Not protected
1059                                 return false;
1060                         }
1061                         return true;
1062                 } else {
1063                         # If it doesn't exist, it can't be protected
1064                         return false;
1065                 }
1066         }
1067
1068         /**
1069          * Does the title correspond to a protected article?
1070          *
1071          * @param $action String the action the page is protected from,
1072          * by default checks all actions.
1073          * @return Bool
1074          */
1075         public function isProtected( $action = '' ) {
1076                 global $wgRestrictionLevels;
1077
1078                 $restrictionTypes = $this->getRestrictionTypes();
1079
1080                 # Special pages have inherent protection
1081                 if( $this->getNamespace() == NS_SPECIAL ) {
1082                         return true;
1083                 }
1084
1085                 # Check regular protection levels
1086                 foreach ( $restrictionTypes as $type ) {
1087                         if ( $action == $type || $action == '' ) {
1088                                 $r = $this->getRestrictions( $type );
1089                                 foreach ( $wgRestrictionLevels as $level ) {
1090                                         if ( in_array( $level, $r ) && $level != '' ) {
1091                                                 return true;
1092                                         }
1093                                 }
1094                         }
1095                 }
1096
1097                 return false;
1098         }
1099
1100         /**
1101          * Is this a conversion table for the LanguageConverter?
1102          *
1103          * @return Bool
1104          */
1105         public function isConversionTable() {
1106                 if(
1107                         $this->getNamespace() == NS_MEDIAWIKI &&
1108                         strpos( $this->getText(), 'Conversiontable' ) !== false
1109                 )
1110                 {
1111                         return true;
1112                 }
1113
1114                 return false;
1115         }
1116
1117         /**
1118          * Is $wgUser watching this page?
1119          *
1120          * @return Bool
1121          */
1122         public function userIsWatching() {
1123                 global $wgUser;
1124
1125                 if ( is_null( $this->mWatched ) ) {
1126                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1127                                 $this->mWatched = false;
1128                         } else {
1129                                 $this->mWatched = $wgUser->isWatched( $this );
1130                         }
1131                 }
1132                 return $this->mWatched;
1133         }
1134
1135         /**
1136          * Can $wgUser perform $action on this page?
1137          * This skips potentially expensive cascading permission checks
1138          * as well as avoids expensive error formatting
1139          *
1140          * Suitable for use for nonessential UI controls in common cases, but
1141          * _not_ for functional access control.
1142          *
1143          * May provide false positives, but should never provide a false negative.
1144          *
1145          * @param $action String action that permission needs to be checked for
1146          * @return Bool
1147          */
1148         public function quickUserCan( $action ) {
1149                 return $this->userCan( $action, false );
1150         }
1151
1152         /**
1153          * Determines if $user is unable to edit this page because it has been protected
1154          * by $wgNamespaceProtection.
1155          *
1156          * @param $user User object, $wgUser will be used if not passed
1157          * @return Bool
1158          */
1159         public function isNamespaceProtected( User $user = null ) {
1160                 global $wgNamespaceProtection;
1161
1162                 if ( $user === null ) {
1163                         global $wgUser;
1164                         $user = $wgUser;
1165                 }
1166
1167                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1168                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1169                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1170                                         return true;
1171                                 }
1172                         }
1173                 }
1174                 return false;
1175         }
1176
1177         /**
1178          * Can $wgUser perform $action on this page?
1179          *
1180          * @param $action String action that permission needs to be checked for
1181          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1182          * @return Bool
1183          */
1184         public function userCan( $action, $doExpensiveQueries = true ) {
1185                 global $wgUser;
1186                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1187         }
1188
1189         /**
1190          * Can $user perform $action on this page?
1191          *
1192          * FIXME: This *does not* check throttles (User::pingLimiter()).
1193          *
1194          * @param $action String action that permission needs to be checked for
1195          * @param $user User to check
1196          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries by
1197          *   skipping checks for cascading protections and user blocks.
1198          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1199          * @return Array of arguments to wfMsg to explain permissions problems.
1200          */
1201         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1202                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1203
1204                 // Remove the errors being ignored.
1205                 foreach ( $errors as $index => $error ) {
1206                         $error_key = is_array( $error ) ? $error[0] : $error;
1207
1208                         if ( in_array( $error_key, $ignoreErrors ) ) {
1209                                 unset( $errors[$index] );
1210                         }
1211                 }
1212
1213                 return $errors;
1214         }
1215
1216         /**
1217          * Permissions checks that fail most often, and which are easiest to test.
1218          *
1219          * @param $action String the action to check
1220          * @param $user User user to check
1221          * @param $errors Array list of current errors
1222          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1223          * @param $short Boolean short circuit on first error
1224          *
1225          * @return Array list of errors
1226          */
1227         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1228                 if ( $action == 'create' ) {
1229                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1230                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1231                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1232                         }
1233                 } elseif ( $action == 'move' ) {
1234                         if ( !$user->isAllowed( 'move-rootuserpages' )
1235                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1236                                 // Show user page-specific message only if the user can move other pages
1237                                 $errors[] = array( 'cant-move-user-page' );
1238                         }
1239
1240                         // Check if user is allowed to move files if it's a file
1241                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1242                                 $errors[] = array( 'movenotallowedfile' );
1243                         }
1244
1245                         if ( !$user->isAllowed( 'move' ) ) {
1246                                 // User can't move anything
1247                                 global $wgGroupPermissions;
1248                                 $userCanMove = false;
1249                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1250                                         $userCanMove = $wgGroupPermissions['user']['move'];
1251                                 }
1252                                 $autoconfirmedCanMove = false;
1253                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1254                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1255                                 }
1256                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1257                                         // custom message if logged-in users without any special rights can move
1258                                         $errors[] = array( 'movenologintext' );
1259                                 } else {
1260                                         $errors[] = array( 'movenotallowed' );
1261                                 }
1262                         }
1263                 } elseif ( $action == 'move-target' ) {
1264                         if ( !$user->isAllowed( 'move' ) ) {
1265                                 // User can't move anything
1266                                 $errors[] = array( 'movenotallowed' );
1267                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1268                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1269                                 // Show user page-specific message only if the user can move other pages
1270                                 $errors[] = array( 'cant-move-to-user-page' );
1271                         }
1272                 } elseif ( !$user->isAllowed( $action ) ) {
1273                         // We avoid expensive display logic for quickUserCan's and such
1274                         $groups = false;
1275                         if ( !$short ) {
1276                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1277                                         User::getGroupsWithPermission( $action ) );
1278                         }
1279
1280                         if ( $groups ) {
1281                                 global $wgLang;
1282                                 $return = array(
1283                                         'badaccess-groups',
1284                                         $wgLang->commaList( $groups ),
1285                                         count( $groups )
1286                                 );
1287                         } else {
1288                                 $return = array( 'badaccess-group0' );
1289                         }
1290                         $errors[] = $return;
1291                 }
1292
1293                 return $errors;
1294         }
1295
1296         /**
1297          * Add the resulting error code to the errors array
1298          *
1299          * @param $errors Array list of current errors
1300          * @param $result Mixed result of errors
1301          *
1302          * @return Array list of errors
1303          */
1304         private function resultToError( $errors, $result ) {
1305                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1306                         // A single array representing an error
1307                         $errors[] = $result;
1308                 } else if ( is_array( $result ) && is_array( $result[0] ) ) {
1309                         // A nested array representing multiple errors
1310                         $errors = array_merge( $errors, $result );
1311                 } else if ( $result !== '' && is_string( $result ) ) {
1312                         // A string representing a message-id
1313                         $errors[] = array( $result );
1314                 } else if ( $result === false ) {
1315                         // a generic "We don't want them to do that"
1316                         $errors[] = array( 'badaccess-group0' );
1317                 }
1318                 return $errors;
1319         }
1320
1321         /**
1322          * Check various permission hooks
1323          *
1324          * @param $action String the action to check
1325          * @param $user User user to check
1326          * @param $errors Array list of current errors
1327          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1328          * @param $short Boolean short circuit on first error
1329          *
1330          * @return Array list of errors
1331          */
1332         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1333                 // Use getUserPermissionsErrors instead
1334                 $result = '';
1335                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1336                         return $result ? array() : array( array( 'badaccess-group0' ) );
1337                 }
1338                 // Check getUserPermissionsErrors hook
1339                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1340                         $errors = $this->resultToError( $errors, $result );
1341                 }
1342                 // Check getUserPermissionsErrorsExpensive hook
1343                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1344                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1345                         $errors = $this->resultToError( $errors, $result );
1346                 }
1347
1348                 return $errors;
1349         }
1350
1351         /**
1352          * Check permissions on special pages & namespaces
1353          *
1354          * @param $action String the action to check
1355          * @param $user User user to check
1356          * @param $errors Array list of current errors
1357          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1358          * @param $short Boolean short circuit on first error
1359          *
1360          * @return Array list of errors
1361          */
1362         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1363                 # Only 'createaccount' and 'execute' can be performed on
1364                 # special pages, which don't actually exist in the DB.
1365                 $specialOKActions = array( 'createaccount', 'execute' );
1366                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1367                         $errors[] = array( 'ns-specialprotected' );
1368                 }
1369
1370                 # Check $wgNamespaceProtection for restricted namespaces
1371                 if ( $this->isNamespaceProtected( $user ) ) {
1372                         $ns = $this->mNamespace == NS_MAIN ?
1373                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1374                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1375                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1376                 }
1377
1378                 return $errors;
1379         }
1380
1381         /**
1382          * Check CSS/JS sub-page permissions
1383          *
1384          * @param $action String the action to check
1385          * @param $user User user to check
1386          * @param $errors Array list of current errors
1387          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1388          * @param $short Boolean short circuit on first error
1389          *
1390          * @return Array list of errors
1391          */
1392         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1393                 # Protect css/js subpages of user pages
1394                 # XXX: this might be better using restrictions
1395                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssSubpage()
1396                 #      and $this->userCanEditJsSubpage() from working
1397                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1398                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1399                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1400                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1401                                 $errors[] = array( 'customcssjsprotected' );
1402                         } else if ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1403                                 $errors[] = array( 'customcssjsprotected' );
1404                         }
1405                 }
1406
1407                 return $errors;
1408         }
1409
1410         /**
1411          * Check against page_restrictions table requirements on this
1412          * page. The user must possess all required rights for this
1413          * action.
1414          *
1415          * @param $action String the action to check
1416          * @param $user User user to check
1417          * @param $errors Array list of current errors
1418          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1419          * @param $short Boolean short circuit on first error
1420          *
1421          * @return Array list of errors
1422          */
1423         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1424                 foreach ( $this->getRestrictions( $action ) as $right ) {
1425                         // Backwards compatibility, rewrite sysop -> protect
1426                         if ( $right == 'sysop' ) {
1427                                 $right = 'protect';
1428                         }
1429                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1430                                 // Users with 'editprotected' permission can edit protected pages
1431                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected' ) ) {
1432                                         // Users with 'editprotected' permission cannot edit protected pages
1433                                         // with cascading option turned on.
1434                                         if ( $this->mCascadeRestriction ) {
1435                                                 $errors[] = array( 'protectedpagetext', $right );
1436                                         }
1437                                 } else {
1438                                         $errors[] = array( 'protectedpagetext', $right );
1439                                 }
1440                         }
1441                 }
1442
1443                 return $errors;
1444         }
1445
1446         /**
1447          * Check restrictions on cascading pages.
1448          *
1449          * @param $action String the action to check
1450          * @param $user User to check
1451          * @param $errors Array list of current errors
1452          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1453          * @param $short Boolean short circuit on first error
1454          *
1455          * @return Array list of errors
1456          */
1457         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1458                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1459                         # We /could/ use the protection level on the source page, but it's
1460                         # fairly ugly as we have to establish a precedence hierarchy for pages
1461                         # included by multiple cascade-protected pages. So just restrict
1462                         # it to people with 'protect' permission, as they could remove the
1463                         # protection anyway.
1464                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1465                         # Cascading protection depends on more than this page...
1466                         # Several cascading protected pages may include this page...
1467                         # Check each cascading level
1468                         # This is only for protection restrictions, not for all actions
1469                         if ( isset( $restrictions[$action] ) ) {
1470                                 foreach ( $restrictions[$action] as $right ) {
1471                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1472                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1473                                                 $pages = '';
1474                                                 foreach ( $cascadingSources as $page )
1475                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1476                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1477                                         }
1478                                 }
1479                         }
1480                 }
1481
1482                 return $errors;
1483         }
1484
1485         /**
1486          * Check action permissions not already checked in checkQuickPermissions
1487          *
1488          * @param $action String the action to check
1489          * @param $user User to check
1490          * @param $errors Array list of current errors
1491          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1492          * @param $short Boolean short circuit on first error
1493          *
1494          * @return Array list of errors
1495          */
1496         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1497                 if ( $action == 'protect' ) {
1498                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1499                                 // If they can't edit, they shouldn't protect.
1500                                 $errors[] = array( 'protect-cantedit' );
1501                         }
1502                 } elseif ( $action == 'create' ) {
1503                         $title_protection = $this->getTitleProtection();
1504                         if( $title_protection ) {
1505                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1506                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1507                                 }
1508                                 if( $title_protection['pt_create_perm'] == '' || !$user->isAllowed( $title_protection['pt_create_perm'] ) ) {
1509                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1510                                 }
1511                         }
1512                 } elseif ( $action == 'move' ) {
1513                         // Check for immobile pages
1514                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1515                                 // Specific message for this case
1516                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1517                         } elseif ( !$this->isMovable() ) {
1518                                 // Less specific message for rarer cases
1519                                 $errors[] = array( 'immobile-page' );
1520                         }
1521                 } elseif ( $action == 'move-target' ) {
1522                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1523                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1524                         } elseif ( !$this->isMovable() ) {
1525                                 $errors[] = array( 'immobile-target-page' );
1526                         }
1527                 }
1528                 return $errors;
1529         }
1530
1531         /**
1532          * Check that the user isn't blocked from editting.
1533          *
1534          * @param $action String the action to check
1535          * @param $user User to check
1536          * @param $errors Array list of current errors
1537          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1538          * @param $short Boolean short circuit on first error
1539          *
1540          * @return Array list of errors
1541          */
1542         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1543                 if( !$doExpensiveQueries ) {
1544                         return $errors;
1545                 }
1546
1547                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1548
1549                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1550                         $errors[] = array( 'confirmedittext' );
1551                 }
1552
1553                 if ( in_array( $action, array( 'read', 'createaccount', 'unblock' ) ) ){
1554                         // Edit blocks should not affect reading.
1555                         // Account creation blocks handled at userlogin.
1556                         // Unblocking handled in SpecialUnblock
1557                 } elseif( ( $action == 'edit' || $action == 'create' ) && !$user->isBlockedFrom( $this ) ){
1558                         // Don't block the user from editing their own talk page unless they've been
1559                         // explicitly blocked from that too.
1560                 } elseif( $user->isBlocked() && $user->mBlock->prevents( $action ) !== false ) {
1561                         $block = $user->mBlock;
1562
1563                         // This is from OutputPage::blockedPage
1564                         // Copied at r23888 by werdna
1565
1566                         $id = $user->blockedBy();
1567                         $reason = $user->blockedFor();
1568                         if ( $reason == '' ) {
1569                                 $reason = wfMsg( 'blockednoreason' );
1570                         }
1571                         $ip = wfGetIP();
1572
1573                         if ( is_numeric( $id ) ) {
1574                                 $name = User::whoIs( $id );
1575                         } else {
1576                                 $name = $id;
1577                         }
1578
1579                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1580                         $blockid = $block->getId();
1581                         $blockExpiry = $user->mBlock->mExpiry;
1582                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1583                         if ( $blockExpiry == 'infinity' ) {
1584                                 $blockExpiry = wfMessage( 'infiniteblock' )->text();
1585                         } else {
1586                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1587                         }
1588
1589                         $intended = strval( $user->mBlock->getTarget() );
1590
1591                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1592                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1593                 }
1594
1595                 return $errors;
1596         }
1597
1598         /**
1599          * Can $user perform $action on this page? This is an internal function,
1600          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1601          * checks on wfReadOnly() and blocks)
1602          *
1603          * @param $action String action that permission needs to be checked for
1604          * @param $user User to check
1605          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1606          * @param $short Bool Set this to true to stop after the first permission error.
1607          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1608          */
1609         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1610                 wfProfileIn( __METHOD__ );
1611
1612                 $errors = array();
1613                 $checks = array(
1614                         'checkQuickPermissions',
1615                         'checkPermissionHooks',
1616                         'checkSpecialsAndNSPermissions',
1617                         'checkCSSandJSPermissions',
1618                         'checkPageRestrictions',
1619                         'checkCascadingSourcesRestrictions',
1620                         'checkActionPermissions',
1621                         'checkUserBlock'
1622                 );
1623
1624                 while( count( $checks ) > 0 &&
1625                            !( $short && count( $errors ) > 0 ) ) {
1626                         $method = array_shift( $checks );
1627                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1628                 }
1629
1630                 wfProfileOut( __METHOD__ );
1631                 return $errors;
1632         }
1633
1634         /**
1635          * Is this title subject to title protection?
1636          * Title protection is the one applied against creation of such title.
1637          *
1638          * @return Mixed An associative array representing any existent title
1639          *   protection, or false if there's none.
1640          */
1641         private function getTitleProtection() {
1642                 // Can't protect pages in special namespaces
1643                 if ( $this->getNamespace() < 0 ) {
1644                         return false;
1645                 }
1646
1647                 // Can't protect pages that exist.
1648                 if ( $this->exists() ) {
1649                         return false;
1650                 }
1651
1652                 if ( !isset( $this->mTitleProtection ) ) {
1653                         $dbr = wfGetDB( DB_SLAVE );
1654                         $res = $dbr->select( 'protected_titles', '*',
1655                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1656                                 __METHOD__ );
1657
1658                         // fetchRow returns false if there are no rows.
1659                         $this->mTitleProtection = $dbr->fetchRow( $res );
1660                 }
1661                 return $this->mTitleProtection;
1662         }
1663
1664         /**
1665          * Update the title protection status
1666          *
1667          * @param $create_perm String Permission required for creation
1668          * @param $reason String Reason for protection
1669          * @param $expiry String Expiry timestamp
1670          * @return boolean true
1671          */
1672         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1673                 global $wgUser, $wgContLang;
1674
1675                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1676                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1677                         // No change
1678                         return true;
1679                 }
1680
1681                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1682
1683                 $dbw = wfGetDB( DB_MASTER );
1684
1685                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
1686
1687                 $expiry_description = '';
1688                 if ( $encodedExpiry != $dbw->getInfinity() ) {
1689                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1690                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1691                 } else {
1692                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1693                 }
1694
1695                 # Update protection table
1696                 if ( $create_perm != '' ) {
1697                         $this->mTitleProtection = array(
1698                                         'pt_namespace' => $namespace,
1699                                         'pt_title' => $title,
1700                                         'pt_create_perm' => $create_perm,
1701                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
1702                                         'pt_expiry' => $encodedExpiry,
1703                                         'pt_user' => $wgUser->getId(),
1704                                         'pt_reason' => $reason,
1705                                 );
1706                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1707                                 $this->mTitleProtection, __METHOD__     );
1708                 } else {
1709                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1710                                 'pt_title' => $title ), __METHOD__ );
1711                         $this->mTitleProtection = false;
1712                 }
1713
1714                 # Update the protection log
1715                 if ( $dbw->affectedRows() ) {
1716                         $log = new LogPage( 'protect' );
1717
1718                         if ( $create_perm ) {
1719                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1720                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1721                         } else {
1722                                 $log->addEntry( 'unprotect', $this, $reason );
1723                         }
1724                 }
1725
1726                 return true;
1727         }
1728
1729         /**
1730          * Remove any title protection due to page existing
1731          */
1732         public function deleteTitleProtection() {
1733                 $dbw = wfGetDB( DB_MASTER );
1734
1735                 $dbw->delete(
1736                         'protected_titles',
1737                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1738                         __METHOD__
1739                 );
1740                 $this->mTitleProtection = false;
1741         }
1742
1743         /**
1744          * Would anybody with sufficient privileges be able to move this page?
1745          * Some pages just aren't movable.
1746          *
1747          * @return Bool TRUE or FALSE
1748          */
1749         public function isMovable() {
1750                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1751         }
1752
1753         /**
1754          * Can $wgUser read this page?
1755          *
1756          * @return Bool
1757          * @todo fold these checks into userCan()
1758          */
1759         public function userCanRead() {
1760                 global $wgUser, $wgGroupPermissions;
1761
1762                 static $useShortcut = null;
1763
1764                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1765                 if ( is_null( $useShortcut ) ) {
1766                         global $wgRevokePermissions;
1767                         $useShortcut = true;
1768                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1769                                 # Not a public wiki, so no shortcut
1770                                 $useShortcut = false;
1771                         } elseif ( !empty( $wgRevokePermissions ) ) {
1772                                 /*
1773                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1774                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1775                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1776                                  * reading is allowed.
1777                                  */
1778                                 foreach ( $wgRevokePermissions as $perms ) {
1779                                         if ( !empty( $perms['read'] ) ) {
1780                                                 # We might be removing the read right from the user, so no shortcut
1781                                                 $useShortcut = false;
1782                                                 break;
1783                                         }
1784                                 }
1785                         }
1786                 }
1787
1788                 $result = null;
1789                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1790                 if ( $result !== null ) {
1791                         return $result;
1792                 }
1793
1794                 # Shortcut for public wikis, allows skipping quite a bit of code
1795                 if ( $useShortcut ) {
1796                         return true;
1797                 }
1798
1799                 if ( $wgUser->isAllowed( 'read' ) ) {
1800                         return true;
1801                 } else {
1802                         global $wgWhitelistRead;
1803
1804                         # Always grant access to the login page.
1805                         # Even anons need to be able to log in.
1806                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'ChangePassword' ) ) {
1807                                 return true;
1808                         }
1809
1810                         # Bail out if there isn't whitelist
1811                         if ( !is_array( $wgWhitelistRead ) ) {
1812                                 return false;
1813                         }
1814
1815                         # Check for explicit whitelisting
1816                         $name = $this->getPrefixedText();
1817                         $dbName = $this->getPrefixedDBKey();
1818                         // Check with and without underscores
1819                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1820                                 return true;
1821
1822                         # Old settings might have the title prefixed with
1823                         # a colon for main-namespace pages
1824                         if ( $this->getNamespace() == NS_MAIN ) {
1825                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1826                                         return true;
1827                                 }
1828                         }
1829
1830                         # If it's a special page, ditch the subpage bit and check again
1831                         if ( $this->getNamespace() == NS_SPECIAL ) {
1832                                 $name = $this->getDBkey();
1833                                 list( $name, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $name );
1834                                 if ( $name === false ) {
1835                                         # Invalid special page, but we show standard login required message
1836                                         return false;
1837                                 }
1838
1839                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1840                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1841                                         return true;
1842                                 }
1843                         }
1844
1845                 }
1846                 return false;
1847         }
1848
1849         /**
1850          * Is this the mainpage?
1851          * @note Title::newFromText seams to be sufficiently optimized by the title
1852          * cache that we don't need to over-optimize by doing direct comparisons and
1853          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1854          * ends up reporting something differently than $title->isMainPage();
1855          *
1856          * @return Bool
1857          */
1858         public function isMainPage() {
1859                 return $this->equals( Title::newMainPage() );
1860         }
1861
1862         /**
1863          * Is this a talk page of some sort?
1864          *
1865          * @return Bool
1866          */
1867         public function isTalkPage() {
1868                 return MWNamespace::isTalk( $this->getNamespace() );
1869         }
1870
1871         /**
1872          * Is this a subpage?
1873          *
1874          * @return Bool
1875          */
1876         public function isSubpage() {
1877                 return MWNamespace::hasSubpages( $this->mNamespace )
1878                         ? strpos( $this->getText(), '/' ) !== false
1879                         : false;
1880         }
1881
1882         /**
1883          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1884          *
1885          * @return Bool
1886          */
1887         public function hasSubpages() {
1888                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1889                         # Duh
1890                         return false;
1891                 }
1892
1893                 # We dynamically add a member variable for the purpose of this method
1894                 # alone to cache the result.  There's no point in having it hanging
1895                 # around uninitialized in every Title object; therefore we only add it
1896                 # if needed and don't declare it statically.
1897                 if ( isset( $this->mHasSubpages ) ) {
1898                         return $this->mHasSubpages;
1899                 }
1900
1901                 $subpages = $this->getSubpages( 1 );
1902                 if ( $subpages instanceof TitleArray ) {
1903                         return $this->mHasSubpages = (bool)$subpages->count();
1904                 }
1905                 return $this->mHasSubpages = false;
1906         }
1907
1908         /**
1909          * Get all subpages of this page.
1910          *
1911          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
1912          * @return mixed TitleArray, or empty array if this page's namespace
1913          *  doesn't allow subpages
1914          */
1915         public function getSubpages( $limit = -1 ) {
1916                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1917                         return array();
1918                 }
1919
1920                 $dbr = wfGetDB( DB_SLAVE );
1921                 $conds['page_namespace'] = $this->getNamespace();
1922                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1923                 $options = array();
1924                 if ( $limit > -1 ) {
1925                         $options['LIMIT'] = $limit;
1926                 }
1927                 return $this->mSubpages = TitleArray::newFromResult(
1928                         $dbr->select( 'page',
1929                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1930                                 $conds,
1931                                 __METHOD__,
1932                                 $options
1933                         )
1934                 );
1935         }
1936
1937         /**
1938          * Could this page contain custom CSS or JavaScript, based
1939          * on the title?
1940          *
1941          * @return Bool
1942          */
1943         public function isCssOrJsPage() {
1944                 return $this->mNamespace == NS_MEDIAWIKI
1945                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1946         }
1947
1948         /**
1949          * Is this a .css or .js subpage of a user page?
1950          * @return Bool
1951          */
1952         public function isCssJsSubpage() {
1953                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1954         }
1955
1956         /**
1957          * Is this a *valid* .css or .js subpage of a user page?
1958          *
1959          * @return Bool
1960          * @deprecated since 1.17
1961          */
1962         public function isValidCssJsSubpage() {
1963                 return $this->isCssJsSubpage();
1964         }
1965
1966         /**
1967          * Trim down a .css or .js subpage title to get the corresponding skin name
1968          *
1969          * @return string containing skin name from .css or .js subpage title
1970          */
1971         public function getSkinFromCssJsSubpage() {
1972                 $subpage = explode( '/', $this->mTextform );
1973                 $subpage = $subpage[ count( $subpage ) - 1 ];
1974                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1975         }
1976
1977         /**
1978          * Is this a .css subpage of a user page?
1979          *
1980          * @return Bool
1981          */
1982         public function isCssSubpage() {
1983                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1984         }
1985
1986         /**
1987          * Is this a .js subpage of a user page?
1988          *
1989          * @return Bool
1990          */
1991         public function isJsSubpage() {
1992                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1993         }
1994
1995         /**
1996          * Protect css subpages of user pages: can $wgUser edit
1997          * this page?
1998          *
1999          * @return Bool
2000          * @todo XXX: this might be better using restrictions
2001          */
2002         public function userCanEditCssSubpage() {
2003                 global $wgUser;
2004                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2005                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2006         }
2007
2008         /**
2009          * Protect js subpages of user pages: can $wgUser edit
2010          * this page?
2011          *
2012          * @return Bool
2013          * @todo XXX: this might be better using restrictions
2014          */
2015         public function userCanEditJsSubpage() {
2016                 global $wgUser;
2017                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2018                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2019         }
2020
2021         /**
2022          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2023          *
2024          * @return Bool If the page is subject to cascading restrictions.
2025          */
2026         public function isCascadeProtected() {
2027                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2028                 return ( $sources > 0 );
2029         }
2030
2031         /**
2032          * Cascading protection: Get the source of any cascading restrictions on this page.
2033          *
2034          * @param $getPages Bool Whether or not to retrieve the actual pages
2035          *        that the restrictions have come from.
2036          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2037          *     have come, false for none, or true if such restrictions exist, but $getPages
2038          *     was not set.  The restriction array is an array of each type, each of which
2039          *     contains a array of unique groups.
2040          */
2041         public function getCascadeProtectionSources( $getPages = true ) {
2042                 global $wgContLang;
2043                 $pagerestrictions = array();
2044
2045                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2046                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2047                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2048                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2049                 }
2050
2051                 wfProfileIn( __METHOD__ );
2052
2053                 $dbr = wfGetDB( DB_SLAVE );
2054
2055                 if ( $this->getNamespace() == NS_FILE ) {
2056                         $tables = array( 'imagelinks', 'page_restrictions' );
2057                         $where_clauses = array(
2058                                 'il_to' => $this->getDBkey(),
2059                                 'il_from=pr_page',
2060                                 'pr_cascade' => 1
2061                         );
2062                 } else {
2063                         $tables = array( 'templatelinks', 'page_restrictions' );
2064                         $where_clauses = array(
2065                                 'tl_namespace' => $this->getNamespace(),
2066                                 'tl_title' => $this->getDBkey(),
2067                                 'tl_from=pr_page',
2068                                 'pr_cascade' => 1
2069                         );
2070                 }
2071
2072                 if ( $getPages ) {
2073                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2074                                                    'pr_expiry', 'pr_type', 'pr_level' );
2075                         $where_clauses[] = 'page_id=pr_page';
2076                         $tables[] = 'page';
2077                 } else {
2078                         $cols = array( 'pr_expiry' );
2079                 }
2080
2081                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2082
2083                 $sources = $getPages ? array() : false;
2084                 $now = wfTimestampNow();
2085                 $purgeExpired = false;
2086
2087                 foreach ( $res as $row ) {
2088                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2089                         if ( $expiry > $now ) {
2090                                 if ( $getPages ) {
2091                                         $page_id = $row->pr_page;
2092                                         $page_ns = $row->page_namespace;
2093                                         $page_title = $row->page_title;
2094                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2095                                         # Add groups needed for each restriction type if its not already there
2096                                         # Make sure this restriction type still exists
2097
2098                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2099                                                 $pagerestrictions[$row->pr_type] = array();
2100                                         }
2101
2102                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2103                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2104                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2105                                         }
2106                                 } else {
2107                                         $sources = true;
2108                                 }
2109                         } else {
2110                                 // Trigger lazy purge of expired restrictions from the db
2111                                 $purgeExpired = true;
2112                         }
2113                 }
2114                 if ( $purgeExpired ) {
2115                         Title::purgeExpiredRestrictions();
2116                 }
2117
2118                 if ( $getPages ) {
2119                         $this->mCascadeSources = $sources;
2120                         $this->mCascadingRestrictions = $pagerestrictions;
2121                 } else {
2122                         $this->mHasCascadingRestrictions = $sources;
2123                 }
2124
2125                 wfProfileOut( __METHOD__ );
2126                 return array( $sources, $pagerestrictions );
2127         }
2128
2129         /**
2130          * Returns cascading restrictions for the current article
2131          *
2132          * @return Boolean
2133          */
2134         function areRestrictionsCascading() {
2135                 if ( !$this->mRestrictionsLoaded ) {
2136                         $this->loadRestrictions();
2137                 }
2138
2139                 return $this->mCascadeRestriction;
2140         }
2141
2142         /**
2143          * Loads a string into mRestrictions array
2144          *
2145          * @param $res Resource restrictions as an SQL result.
2146          * @param $oldFashionedRestrictions String comma-separated list of page
2147          *        restrictions from page table (pre 1.10)
2148          */
2149         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2150                 $rows = array();
2151
2152                 foreach ( $res as $row ) {
2153                         $rows[] = $row;
2154                 }
2155
2156                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2157         }
2158
2159         /**
2160          * Compiles list of active page restrictions from both page table (pre 1.10)
2161          * and page_restrictions table for this existing page.
2162          * Public for usage by LiquidThreads.
2163          *
2164          * @param $rows array of db result objects
2165          * @param $oldFashionedRestrictions string comma-separated list of page
2166          *        restrictions from page table (pre 1.10)
2167          */
2168         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2169                 global $wgContLang;
2170                 $dbr = wfGetDB( DB_SLAVE );
2171
2172                 $restrictionTypes = $this->getRestrictionTypes();
2173
2174                 foreach ( $restrictionTypes as $type ) {
2175                         $this->mRestrictions[$type] = array();
2176                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2177                 }
2178
2179                 $this->mCascadeRestriction = false;
2180
2181                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2182
2183                 if ( $oldFashionedRestrictions === null ) {
2184                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2185                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2186                 }
2187
2188                 if ( $oldFashionedRestrictions != '' ) {
2189
2190                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2191                                 $temp = explode( '=', trim( $restrict ) );
2192                                 if ( count( $temp ) == 1 ) {
2193                                         // old old format should be treated as edit/move restriction
2194                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2195                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2196                                 } else {
2197                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2198                                 }
2199                         }
2200
2201                         $this->mOldRestrictions = true;
2202
2203                 }
2204
2205                 if ( count( $rows ) ) {
2206                         # Current system - load second to make them override.
2207                         $now = wfTimestampNow();
2208                         $purgeExpired = false;
2209
2210                         # Cycle through all the restrictions.
2211                         foreach ( $rows as $row ) {
2212
2213                                 // Don't take care of restrictions types that aren't allowed
2214                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2215                                         continue;
2216
2217                                 // This code should be refactored, now that it's being used more generally,
2218                                 // But I don't really see any harm in leaving it in Block for now -werdna
2219                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2220
2221                                 // Only apply the restrictions if they haven't expired!
2222                                 if ( !$expiry || $expiry > $now ) {
2223                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2224                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2225
2226                                         $this->mCascadeRestriction |= $row->pr_cascade;
2227                                 } else {
2228                                         // Trigger a lazy purge of expired restrictions
2229                                         $purgeExpired = true;
2230                                 }
2231                         }
2232
2233                         if ( $purgeExpired ) {
2234                                 Title::purgeExpiredRestrictions();
2235                         }
2236                 }
2237
2238                 $this->mRestrictionsLoaded = true;
2239         }
2240
2241         /**
2242          * Load restrictions from the page_restrictions table
2243          *
2244          * @param $oldFashionedRestrictions String comma-separated list of page
2245          *        restrictions from page table (pre 1.10)
2246          */
2247         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2248                 global $wgContLang;
2249                 if ( !$this->mRestrictionsLoaded ) {
2250                         if ( $this->exists() ) {
2251                                 $dbr = wfGetDB( DB_SLAVE );
2252
2253                                 $res = $dbr->select(
2254                                         'page_restrictions',
2255                                         '*',
2256                                         array( 'pr_page' => $this->getArticleId() ),
2257                                         __METHOD__
2258                                 );
2259
2260                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2261                         } else {
2262                                 $title_protection = $this->getTitleProtection();
2263
2264                                 if ( $title_protection ) {
2265                                         $now = wfTimestampNow();
2266                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2267
2268                                         if ( !$expiry || $expiry > $now ) {
2269                                                 // Apply the restrictions
2270                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2271                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2272                                         } else { // Get rid of the old restrictions
2273                                                 Title::purgeExpiredRestrictions();
2274                                                 $this->mTitleProtection = false;
2275                                         }
2276                                 } else {
2277                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2278                                 }
2279                                 $this->mRestrictionsLoaded = true;
2280                         }
2281                 }
2282         }
2283
2284         /**
2285          * Purge expired restrictions from the page_restrictions table
2286          */
2287         static function purgeExpiredRestrictions() {
2288                 $dbw = wfGetDB( DB_MASTER );
2289                 $dbw->delete(
2290                         'page_restrictions',
2291                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2292                         __METHOD__
2293                 );
2294
2295                 $dbw->delete(
2296                         'protected_titles',
2297                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2298                         __METHOD__
2299                 );
2300         }
2301
2302         /**
2303          * Accessor/initialisation for mRestrictions
2304          *
2305          * @param $action String action that permission needs to be checked for
2306          * @return Array of Strings the array of groups allowed to edit this article
2307          */
2308         public function getRestrictions( $action ) {
2309                 if ( !$this->mRestrictionsLoaded ) {
2310                         $this->loadRestrictions();
2311                 }
2312                 return isset( $this->mRestrictions[$action] )
2313                                 ? $this->mRestrictions[$action]
2314                                 : array();
2315         }
2316
2317         /**
2318          * Get the expiry time for the restriction against a given action
2319          *
2320          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2321          *      or not protected at all, or false if the action is not recognised.
2322          */
2323         public function getRestrictionExpiry( $action ) {
2324                 if ( !$this->mRestrictionsLoaded ) {
2325                         $this->loadRestrictions();
2326                 }
2327                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2328         }
2329
2330         /**
2331          * Is there a version of this page in the deletion archive?
2332          *
2333          * @return Int the number of archived revisions
2334          */
2335         public function isDeleted() {
2336                 if ( $this->getNamespace() < 0 ) {
2337                         $n = 0;
2338                 } else {
2339                         $dbr = wfGetDB( DB_SLAVE );
2340                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2341                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2342                                 __METHOD__
2343                         );
2344                         if ( $this->getNamespace() == NS_FILE ) {
2345                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2346                                         array( 'fa_name' => $this->getDBkey() ),
2347                                         __METHOD__
2348                                 );
2349                         }
2350                 }
2351                 return (int)$n;
2352         }
2353
2354         /**
2355          * Is there a version of this page in the deletion archive?
2356          *
2357          * @return Boolean
2358          */
2359         public function isDeletedQuick() {
2360                 if ( $this->getNamespace() < 0 ) {
2361                         return false;
2362                 }
2363                 $dbr = wfGetDB( DB_SLAVE );
2364                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2365                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2366                         __METHOD__
2367                 );
2368                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2369                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2370                                 array( 'fa_name' => $this->getDBkey() ),
2371                                 __METHOD__
2372                         );
2373                 }
2374                 return $deleted;
2375         }
2376
2377         /**
2378          * Get the article ID for this Title from the link cache,
2379          * adding it if necessary
2380          *
2381          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2382          *  for update
2383          * @return Int the ID
2384          */
2385         public function getArticleID( $flags = 0 ) {
2386                 if ( $this->getNamespace() < 0 ) {
2387                         return $this->mArticleID = 0;
2388                 }
2389                 $linkCache = LinkCache::singleton();
2390                 if ( $flags & self::GAID_FOR_UPDATE ) {
2391                         $oldUpdate = $linkCache->forUpdate( true );
2392                         $linkCache->clearLink( $this );
2393                         $this->mArticleID = $linkCache->addLinkObj( $this );
2394                         $linkCache->forUpdate( $oldUpdate );
2395                 } else {
2396                         if ( -1 == $this->mArticleID ) {
2397                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2398                         }
2399                 }
2400                 return $this->mArticleID;
2401         }
2402
2403         /**
2404          * Is this an article that is a redirect 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 Bool
2409          */
2410         public function isRedirect( $flags = 0 ) {
2411                 if ( !is_null( $this->mRedirect ) ) {
2412                         return $this->mRedirect;
2413                 }
2414                 # Calling getArticleID() loads the field from cache as needed
2415                 if ( !$this->getArticleID( $flags ) ) {
2416                         return $this->mRedirect = false;
2417                 }
2418                 $linkCache = LinkCache::singleton();
2419                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2420
2421                 return $this->mRedirect;
2422         }
2423
2424         /**
2425          * What is the length of this page?
2426          * Uses link cache, adding it if necessary
2427          *
2428          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2429          * @return Int
2430          */
2431         public function getLength( $flags = 0 ) {
2432                 if ( $this->mLength != -1 ) {
2433                         return $this->mLength;
2434                 }
2435                 # Calling getArticleID() loads the field from cache as needed
2436                 if ( !$this->getArticleID( $flags ) ) {
2437                         return $this->mLength = 0;
2438                 }
2439                 $linkCache = LinkCache::singleton();
2440                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2441
2442                 return $this->mLength;
2443         }
2444
2445         /**
2446          * What is the page_latest field for this page?
2447          *
2448          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2449          * @return Int or 0 if the page doesn't exist
2450          */
2451         public function getLatestRevID( $flags = 0 ) {
2452                 if ( $this->mLatestID !== false ) {
2453                         return intval( $this->mLatestID );
2454                 }
2455                 # Calling getArticleID() loads the field from cache as needed
2456                 if ( !$this->getArticleID( $flags ) ) {
2457                         return $this->mLatestID = 0;
2458                 }
2459                 $linkCache = LinkCache::singleton();
2460                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2461
2462                 return $this->mLatestID;
2463         }
2464
2465         /**
2466          * This clears some fields in this object, and clears any associated
2467          * keys in the "bad links" section of the link cache.
2468          *
2469          * - This is called from Article::doEdit() and Article::insertOn() to allow
2470          * loading of the new page_id. It's also called from
2471          * Article::doDeleteArticle()
2472          *
2473          * @param $newid Int the new Article ID
2474          */
2475         public function resetArticleID( $newid ) {
2476                 $linkCache = LinkCache::singleton();
2477                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2478
2479                 if ( $newid === false ) {
2480                         $this->mArticleID = -1;
2481                 } else {
2482                         $this->mArticleID = intval( $newid );
2483                 }
2484                 $this->mRestrictionsLoaded = false;
2485                 $this->mRestrictions = array();
2486                 $this->mRedirect = null;
2487                 $this->mLength = -1;
2488                 $this->mLatestID = false;
2489         }
2490
2491         /**
2492          * Updates page_touched for this page; called from LinksUpdate.php
2493          *
2494          * @return Bool true if the update succeded
2495          */
2496         public function invalidateCache() {
2497                 if ( wfReadOnly() ) {
2498                         return;
2499                 }
2500                 $dbw = wfGetDB( DB_MASTER );
2501                 $success = $dbw->update(
2502                         'page',
2503                         array( 'page_touched' => $dbw->timestamp() ),
2504                         $this->pageCond(),
2505                         __METHOD__
2506                 );
2507                 HTMLFileCache::clearFileCache( $this );
2508                 return $success;
2509         }
2510
2511         /**
2512          * Prefix some arbitrary text with the namespace or interwiki prefix
2513          * of this object
2514          *
2515          * @param $name String the text
2516          * @return String the prefixed text
2517          * @private
2518          */
2519         private function prefix( $name ) {
2520                 $p = '';
2521                 if ( $this->mInterwiki != '' ) {
2522                         $p = $this->mInterwiki . ':';
2523                 }
2524
2525                 if ( 0 != $this->mNamespace ) {
2526                         $p .= $this->getNsText() . ':';
2527                 }
2528                 return $p . $name;
2529         }
2530
2531         /**
2532          * Returns a simple regex that will match on characters and sequences invalid in titles.
2533          * Note that this doesn't pick up many things that could be wrong with titles, but that
2534          * replacing this regex with something valid will make many titles valid.
2535          *
2536          * @return String regex string
2537          */
2538         static function getTitleInvalidRegex() {
2539                 static $rxTc = false;
2540                 if ( !$rxTc ) {
2541                         # Matching titles will be held as illegal.
2542                         $rxTc = '/' .
2543                                 # Any character not allowed is forbidden...
2544                                 '[^' . Title::legalChars() . ']' .
2545                                 # URL percent encoding sequences interfere with the ability
2546                                 # to round-trip titles -- you can't link to them consistently.
2547                                 '|%[0-9A-Fa-f]{2}' .
2548                                 # XML/HTML character references produce similar issues.
2549                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2550                                 '|&#[0-9]+;' .
2551                                 '|&#x[0-9A-Fa-f]+;' .
2552                                 '/S';
2553                 }
2554
2555                 return $rxTc;
2556         }
2557
2558         /**
2559          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2560          *
2561          * @param $text String containing title to capitalize
2562          * @param $ns int namespace index, defaults to NS_MAIN
2563          * @return String containing capitalized title
2564          */
2565         public static function capitalize( $text, $ns = NS_MAIN ) {
2566                 global $wgContLang;
2567
2568                 if ( MWNamespace::isCapitalized( $ns ) ) {
2569                         return $wgContLang->ucfirst( $text );
2570                 } else {
2571                         return $text;
2572                 }
2573         }
2574
2575         /**
2576          * Secure and split - main initialisation function for this object
2577          *
2578          * Assumes that mDbkeyform has been set, and is urldecoded
2579          * and uses underscores, but not otherwise munged.  This function
2580          * removes illegal characters, splits off the interwiki and
2581          * namespace prefixes, sets the other forms, and canonicalizes
2582          * everything.
2583          *
2584          * @return Bool true on success
2585          */
2586         private function secureAndSplit() {
2587                 global $wgContLang, $wgLocalInterwiki;
2588
2589                 # Initialisation
2590                 $this->mInterwiki = $this->mFragment = '';
2591                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2592
2593                 $dbkey = $this->mDbkeyform;
2594
2595                 # Strip Unicode bidi override characters.
2596                 # Sometimes they slip into cut-n-pasted page titles, where the
2597                 # override chars get included in list displays.
2598                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2599
2600                 # Clean up whitespace
2601                 # Note: use of the /u option on preg_replace here will cause
2602                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2603                 # conveniently disabling them.
2604                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2605                 $dbkey = trim( $dbkey, '_' );
2606
2607                 if ( $dbkey == '' ) {
2608                         return false;
2609                 }
2610
2611                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2612                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2613                         return false;
2614                 }
2615
2616                 $this->mDbkeyform = $dbkey;
2617
2618                 # Initial colon indicates main namespace rather than specified default
2619                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2620                 if ( ':' == $dbkey { 0 } ) {
2621                         $this->mNamespace = NS_MAIN;
2622                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2623                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2624                 }
2625
2626                 # Namespace or interwiki prefix
2627                 $firstPass = true;
2628                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2629                 do {
2630                         $m = array();
2631                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2632                                 $p = $m[1];
2633                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2634                                         # Ordinary namespace
2635                                         $dbkey = $m[2];
2636                                         $this->mNamespace = $ns;
2637                                         # For Talk:X pages, check if X has a "namespace" prefix
2638                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2639                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2640                                                         # Disallow Talk:File:x type titles...
2641                                                         return false;
2642                                                 } else if ( Interwiki::isValidInterwiki( $x[1] ) ) {
2643                                                         # Disallow Talk:Interwiki:x type titles...
2644                                                         return false;
2645                                                 }
2646                                         }
2647                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2648                                         if ( !$firstPass ) {
2649                                                 # Can't make a local interwiki link to an interwiki link.
2650                                                 # That's just crazy!
2651                                                 return false;
2652                                         }
2653
2654                                         # Interwiki link
2655                                         $dbkey = $m[2];
2656                                         $this->mInterwiki = $wgContLang->lc( $p );
2657
2658                                         # Redundant interwiki prefix to the local wiki
2659                                         if ( $wgLocalInterwiki !== false
2660                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2661                                         {
2662                                                 if ( $dbkey == '' ) {
2663                                                         # Can't have an empty self-link
2664                                                         return false;
2665                                                 }
2666                                                 $this->mInterwiki = '';
2667                                                 $firstPass = false;
2668                                                 # Do another namespace split...
2669                                                 continue;
2670                                         }
2671
2672                                         # If there's an initial colon after the interwiki, that also
2673                                         # resets the default namespace
2674                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2675                                                 $this->mNamespace = NS_MAIN;
2676                                                 $dbkey = substr( $dbkey, 1 );
2677                                         }
2678                                 }
2679                                 # If there's no recognized interwiki or namespace,
2680                                 # then let the colon expression be part of the title.
2681                         }
2682                         break;
2683                 } while ( true );
2684
2685                 # We already know that some pages won't be in the database!
2686                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2687                         $this->mArticleID = 0;
2688                 }
2689                 $fragment = strstr( $dbkey, '#' );
2690                 if ( false !== $fragment ) {
2691                         $this->setFragment( $fragment );
2692                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2693                         # remove whitespace again: prevents "Foo_bar_#"
2694                         # becoming "Foo_bar_"
2695                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2696                 }
2697
2698                 # Reject illegal characters.
2699                 $rxTc = self::getTitleInvalidRegex();
2700                 if ( preg_match( $rxTc, $dbkey ) ) {
2701                         return false;
2702                 }
2703
2704                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2705                 # reachable due to the way web browsers deal with 'relative' URLs.
2706                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2707                 if ( strpos( $dbkey, '.' ) !== false &&
2708                          ( $dbkey === '.' || $dbkey === '..' ||
2709                            strpos( $dbkey, './' ) === 0  ||
2710                            strpos( $dbkey, '../' ) === 0 ||
2711                            strpos( $dbkey, '/./' ) !== false ||
2712                            strpos( $dbkey, '/../' ) !== false  ||
2713                            substr( $dbkey, -2 ) == '/.' ||
2714                            substr( $dbkey, -3 ) == '/..' ) )
2715                 {
2716                         return false;
2717                 }
2718
2719                 # Magic tilde sequences? Nu-uh!
2720                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2721                         return false;
2722                 }
2723
2724                 # Limit the size of titles to 255 bytes. This is typically the size of the
2725                 # underlying database field. We make an exception for special pages, which
2726                 # don't need to be stored in the database, and may edge over 255 bytes due
2727                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2728                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2729                   strlen( $dbkey ) > 512 )
2730                 {
2731                         return false;
2732                 }
2733
2734                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2735                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2736                 # other site might be case-sensitive.
2737                 $this->mUserCaseDBKey = $dbkey;
2738                 if ( $this->mInterwiki == '' ) {
2739                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2740                 }
2741
2742                 # Can't make a link to a namespace alone... "empty" local links can only be
2743                 # self-links with a fragment identifier.
2744                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2745                         return false;
2746                 }
2747
2748                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2749                 // IP names are not allowed for accounts, and can only be referring to
2750                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2751                 // there are numerous ways to present the same IP. Having sp:contribs scan
2752                 // them all is silly and having some show the edits and others not is
2753                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2754                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2755                         ? IP::sanitizeIP( $dbkey )
2756                         : $dbkey;
2757
2758                 // Any remaining initial :s are illegal.
2759                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2760                         return false;
2761                 }
2762
2763                 # Fill fields
2764                 $this->mDbkeyform = $dbkey;
2765                 $this->mUrlform = wfUrlencode( $dbkey );
2766
2767                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2768
2769                 return true;
2770         }
2771
2772         /**
2773          * Set the fragment for this title. Removes the first character from the
2774          * specified fragment before setting, so it assumes you're passing it with
2775          * an initial "#".
2776          *
2777          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2778          * Still in active use privately.
2779          *
2780          * @param $fragment String text
2781          */
2782         public function setFragment( $fragment ) {
2783                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2784         }
2785
2786         /**
2787          * Get a Title object associated with the talk page of this article
2788          *
2789          * @return Title the object for the talk page
2790          */
2791         public function getTalkPage() {
2792                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2793         }
2794
2795         /**
2796          * Get a title object associated with the subject page of this
2797          * talk page
2798          *
2799          * @return Title the object for the subject page
2800          */
2801         public function getSubjectPage() {
2802                 // Is this the same title?
2803                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2804                 if ( $this->getNamespace() == $subjectNS ) {
2805                         return $this;
2806                 }
2807                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2808         }
2809
2810         /**
2811          * Get an array of Title objects linking to this Title
2812          * Also stores the IDs in the link cache.
2813          *
2814          * WARNING: do not use this function on arbitrary user-supplied titles!
2815          * On heavily-used templates it will max out the memory.
2816          *
2817          * @param $options Array: may be FOR UPDATE
2818          * @param $table String: table name
2819          * @param $prefix String: fields prefix
2820          * @return Array of Title objects linking here
2821          */
2822         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2823                 $linkCache = LinkCache::singleton();
2824
2825                 if ( count( $options ) > 0 ) {
2826                         $db = wfGetDB( DB_MASTER );
2827                 } else {
2828                         $db = wfGetDB( DB_SLAVE );
2829                 }
2830
2831                 $res = $db->select(
2832                         array( 'page', $table ),
2833                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2834                         array(
2835                                 "{$prefix}_from=page_id",
2836                                 "{$prefix}_namespace" => $this->getNamespace(),
2837                                 "{$prefix}_title"     => $this->getDBkey() ),
2838                         __METHOD__,
2839                         $options
2840                 );
2841
2842                 $retVal = array();
2843                 if ( $db->numRows( $res ) ) {
2844                         foreach ( $res as $row ) {
2845                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2846                                 if ( $titleObj ) {
2847                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2848                                         $retVal[] = $titleObj;
2849                                 }
2850                         }
2851                 }
2852                 return $retVal;
2853         }
2854
2855         /**
2856          * Get an array of Title objects using this Title as a template
2857          * Also stores the IDs in the link cache.
2858          *
2859          * WARNING: do not use this function on arbitrary user-supplied titles!
2860          * On heavily-used templates it will max out the memory.
2861          *
2862          * @param $options Array: may be FOR UPDATE
2863          * @return Array of Title the Title objects linking here
2864          */
2865         public function getTemplateLinksTo( $options = array() ) {
2866                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2867         }
2868
2869         /**
2870          * Get an array of Title objects referring to non-existent articles linked from this page
2871          *
2872          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2873          * @return Array of Title the Title objects
2874          */
2875         public function getBrokenLinksFrom() {
2876                 if ( $this->getArticleId() == 0 ) {
2877                         # All links from article ID 0 are false positives
2878                         return array();
2879                 }
2880
2881                 $dbr = wfGetDB( DB_SLAVE );
2882                 $res = $dbr->select(
2883                         array( 'page', 'pagelinks' ),
2884                         array( 'pl_namespace', 'pl_title' ),
2885                         array(
2886                                 'pl_from' => $this->getArticleId(),
2887                                 'page_namespace IS NULL'
2888                         ),
2889                         __METHOD__, array(),
2890                         array(
2891                                 'page' => array(
2892                                         'LEFT JOIN',
2893                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2894                                 )
2895                         )
2896                 );
2897
2898                 $retVal = array();
2899                 foreach ( $res as $row ) {
2900                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2901                 }
2902                 return $retVal;
2903         }
2904
2905
2906         /**
2907          * Get a list of URLs to purge from the Squid cache when this
2908          * page changes
2909          *
2910          * @return Array of String the URLs
2911          */
2912         public function getSquidURLs() {
2913                 global $wgContLang;
2914
2915                 $urls = array(
2916                         $this->getInternalURL(),
2917                         $this->getInternalURL( 'action=history' )
2918                 );
2919
2920                 // purge variant urls as well
2921                 if ( $wgContLang->hasVariants() ) {
2922                         $variants = $wgContLang->getVariants();
2923                         foreach ( $variants as $vCode ) {
2924                                 $urls[] = $this->getInternalURL( '', $vCode );
2925                         }
2926                 }
2927
2928                 return $urls;
2929         }
2930
2931         /**
2932          * Purge all applicable Squid URLs
2933          */
2934         public function purgeSquid() {
2935                 global $wgUseSquid;
2936                 if ( $wgUseSquid ) {
2937                         $urls = $this->getSquidURLs();
2938                         $u = new SquidUpdate( $urls );
2939                         $u->doUpdate();
2940                 }
2941         }
2942
2943         /**
2944          * Move this page without authentication
2945          *
2946          * @param $nt Title the new page Title
2947          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
2948          */
2949         public function moveNoAuth( &$nt ) {
2950                 return $this->moveTo( $nt, false );
2951         }
2952
2953         /**
2954          * Check whether a given move operation would be valid.
2955          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2956          *
2957          * @param $nt Title the new title
2958          * @param $auth Bool indicates whether $wgUser's permissions
2959          *  should be checked
2960          * @param $reason String is the log summary of the move, used for spam checking
2961          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
2962          */
2963         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2964                 global $wgUser;
2965
2966                 $errors = array();
2967                 if ( !$nt ) {
2968                         // Normally we'd add this to $errors, but we'll get
2969                         // lots of syntax errors if $nt is not an object
2970                         return array( array( 'badtitletext' ) );
2971                 }
2972                 if ( $this->equals( $nt ) ) {
2973                         $errors[] = array( 'selfmove' );
2974                 }
2975                 if ( !$this->isMovable() ) {
2976                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2977                 }
2978                 if ( $nt->getInterwiki() != '' ) {
2979                         $errors[] = array( 'immobile-target-namespace-iw' );
2980                 }
2981                 if ( !$nt->isMovable() ) {
2982                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
2983                 }
2984
2985                 $oldid = $this->getArticleID();
2986                 $newid = $nt->getArticleID();
2987
2988                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2989                         $errors[] = array( 'articleexists' );
2990                 }
2991                 if ( ( $this->getDBkey() == '' ) ||
2992                          ( !$oldid ) ||
2993                          ( $nt->getDBkey() == '' ) ) {
2994                         $errors[] = array( 'badarticleerror' );
2995                 }
2996
2997                 // Image-specific checks
2998                 if ( $this->getNamespace() == NS_FILE ) {
2999                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3000                 }
3001
3002                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3003                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3004                 }
3005
3006                 if ( $auth ) {
3007                         $errors = wfMergeErrorArrays( $errors,
3008                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3009                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3010                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3011                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3012                 }
3013
3014                 $match = EditPage::matchSummarySpamRegex( $reason );
3015                 if ( $match !== false ) {
3016                         // This is kind of lame, won't display nice
3017                         $errors[] = array( 'spamprotectiontext' );
3018                 }
3019
3020                 $err = null;
3021                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3022                         $errors[] = array( 'hookaborted', $err );
3023                 }
3024
3025                 # The move is allowed only if (1) the target doesn't exist, or
3026                 # (2) the target is a redirect to the source, and has no history
3027                 # (so we can undo bad moves right after they're done).
3028
3029                 if ( 0 != $newid ) { # Target exists; check for validity
3030                         if ( !$this->isValidMoveTarget( $nt ) ) {
3031                                 $errors[] = array( 'articleexists' );
3032                         }
3033                 } else {
3034                         $tp = $nt->getTitleProtection();
3035                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3036                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3037                                 $errors[] = array( 'cantmove-titleprotected' );
3038                         }
3039                 }
3040                 if ( empty( $errors ) ) {
3041                         return true;
3042                 }
3043                 return $errors;
3044         }
3045
3046         /**
3047          * Check if the requested move target is a valid file move target
3048          * @param Title $nt Target title
3049          * @return array List of errors
3050          */
3051         protected function validateFileMoveOperation( $nt ) {
3052                 global $wgUser;
3053
3054                 $errors = array();
3055
3056                 if ( $nt->getNamespace() != NS_FILE ) {
3057                         $errors[] = array( 'imagenocrossnamespace' );
3058                 }
3059
3060                 $file = wfLocalFile( $this );
3061                 if ( $file->exists() ) {
3062                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3063                                 $errors[] = array( 'imageinvalidfilename' );
3064                         }
3065                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3066                                 $errors[] = array( 'imagetypemismatch' );
3067                         }
3068                 }
3069
3070                 $destFile = wfLocalFile( $nt );
3071                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destFile->exists() && wfFindFile( $nt ) ) {
3072                         $errors[] = array( 'file-exists-sharedrepo' );
3073                 }
3074
3075                 return $errors;
3076         }
3077
3078         /**
3079          * Move a title to a new location
3080          *
3081          * @param $nt Title the new title
3082          * @param $auth Bool indicates whether $wgUser's permissions
3083          *  should be checked
3084          * @param $reason String the reason for the move
3085          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3086          *  Ignored if the user doesn't have the suppressredirect right.
3087          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3088          */
3089         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3090                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3091                 if ( is_array( $err ) ) {
3092                         return $err;
3093                 }
3094
3095                 // If it is a file, move it first. It is done before all other moving stuff is
3096                 // done because it's hard to revert
3097                 $dbw = wfGetDB( DB_MASTER );
3098                 if ( $this->getNamespace() == NS_FILE ) {
3099                         $file = wfLocalFile( $this );
3100                         if ( $file->exists() ) {
3101                                 $status = $file->move( $nt );
3102                                 if ( !$status->isOk() ) {
3103                                         return $status->getErrorsArray();
3104                                 }
3105                         }
3106                 }
3107
3108                 $dbw->begin(); # If $file was a LocalFile, its transaction would have closed our own.
3109                 $pageid = $this->getArticleID( self::GAID_FOR_UPDATE );
3110                 $protected = $this->isProtected();
3111                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3112
3113                 // Do the actual move
3114                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3115                 if ( is_array( $err ) ) {
3116                         # FIXME: What about the File we have already moved?
3117                         $dbw->rollback();
3118                         return $err;
3119                 }
3120
3121                 $redirid = $this->getArticleID();
3122
3123                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3124                 // cl_timestamp, which may disturb time-based lists on some sites.
3125                 $prefixes = $dbw->select(
3126                         'categorylinks',
3127                         array( 'cl_sortkey_prefix', 'cl_to' ),
3128                         array( 'cl_from' => $pageid ),
3129                         __METHOD__
3130                 );
3131                 foreach ( $prefixes as $prefixRow ) {
3132                         $prefix = $prefixRow->cl_sortkey_prefix;
3133                         $catTo = $prefixRow->cl_to;
3134                         $dbw->update( 'categorylinks',
3135                                 array(
3136                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3137                                                 $nt->getCategorySortkey( $prefix ) ),
3138                                         'cl_timestamp=cl_timestamp' ),
3139                                 array(
3140                                         'cl_from' => $pageid,
3141                                         'cl_to' => $catTo ),
3142                                 __METHOD__
3143                         );
3144                 }
3145
3146                 if ( $protected ) {
3147                         # Protect the redirect title as the title used to be...
3148                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3149                                 array(
3150                                         'pr_page'    => $redirid,
3151                                         'pr_type'    => 'pr_type',
3152                                         'pr_level'   => 'pr_level',
3153                                         'pr_cascade' => 'pr_cascade',
3154                                         'pr_user'    => 'pr_user',
3155                                         'pr_expiry'  => 'pr_expiry'
3156                                 ),
3157                                 array( 'pr_page' => $pageid ),
3158                                 __METHOD__,
3159                                 array( 'IGNORE' )
3160                         );
3161                         # Update the protection log
3162                         $log = new LogPage( 'protect' );
3163                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3164                         if ( $reason ) {
3165                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3166                         }
3167                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) ); // FIXME: $params?
3168                 }
3169
3170                 # Update watchlists
3171                 $oldnamespace = $this->getNamespace() & ~1;
3172                 $newnamespace = $nt->getNamespace() & ~1;
3173                 $oldtitle = $this->getDBkey();
3174                 $newtitle = $nt->getDBkey();
3175
3176                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3177                         WatchedItem::duplicateEntries( $this, $nt );
3178                 }
3179
3180                 # Update search engine
3181                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3182                 $u->doUpdate();
3183                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3184                 $u->doUpdate();
3185
3186                 $dbw->commit();
3187
3188                 # Update site_stats
3189                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3190                         # No longer a content page
3191                         # Not viewed, edited, removing
3192                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3193                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3194                         # Now a content page
3195                         # Not viewed, edited, adding
3196                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3197                 } elseif ( $pageCountChange ) {
3198                         # Redirect added
3199                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3200                 } else {
3201                         # Nothing special
3202                         $u = false;
3203                 }
3204                 if ( $u ) {
3205                         $u->doUpdate();
3206                 }
3207                 # Update message cache for interface messages
3208                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3209                         # @bug 17860: old article can be deleted, if this the case,
3210                         # delete it from message cache
3211                         if ( $this->getArticleID() === 0 ) {
3212                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3213                         } else {
3214                                 $oldarticle = new Article( $this );
3215                                 MessageCache::singleton()->replace( $this->getDBkey(), $oldarticle->getContent() );
3216                         }
3217                 }
3218                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3219                         $newarticle = new Article( $nt );
3220                         MessageCache::singleton()->replace( $nt->getDBkey(), $newarticle->getContent() );
3221                 }
3222
3223                 global $wgUser;
3224                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3225                 return true;
3226         }
3227
3228         /**
3229          * Move page to a title which is either a redirect to the
3230          * source page or nonexistent
3231          *
3232          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3233          * @param $reason String The reason for the move
3234          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3235          *   if the user doesn't have the suppressredirect right
3236          */
3237         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3238                 global $wgUser, $wgContLang;
3239
3240                 $moveOverRedirect = $nt->exists();
3241
3242                 $commentMsg = ( $moveOverRedirect ? '1movedto2_redir' : '1movedto2' );
3243                 $comment = wfMsgForContent( $commentMsg, $this->getPrefixedText(), $nt->getPrefixedText() );
3244
3245                 if ( $reason ) {
3246                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3247                 }
3248                 # Truncate for whole multibyte characters.
3249                 $comment = $wgContLang->truncate( $comment, 255 );
3250
3251                 $oldid = $this->getArticleID();
3252                 $latest = $this->getLatestRevID();
3253
3254                 $oldns = $this->getNamespace();
3255                 $olddbk = $this->getDBkey();
3256
3257                 $dbw = wfGetDB( DB_MASTER );
3258
3259                 if ( $moveOverRedirect ) {
3260                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3261
3262                         $newid = $nt->getArticleID();
3263                         $newns = $nt->getNamespace();
3264                         $newdbk = $nt->getDBkey();
3265
3266                         # Delete the old redirect. We don't save it to history since
3267                         # by definition if we've got here it's rather uninteresting.
3268                         # We have to remove it so that the next step doesn't trigger
3269                         # a conflict on the unique namespace+title index...
3270                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3271                         if ( !$dbw->cascadingDeletes() ) {
3272                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3273                                 global $wgUseTrackbacks;
3274                                 if ( $wgUseTrackbacks ) {
3275                                         $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3276                                 }
3277                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3278                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3279                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3280                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3281                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3282                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3283                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3284                         }
3285                         // If the target page was recently created, it may have an entry in recentchanges still
3286                         $dbw->delete( 'recentchanges',
3287                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3288                                 __METHOD__
3289                         );
3290                 }
3291
3292                 # Save a null revision in the page's history notifying of the move
3293                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3294                 if ( !is_object( $nullRevision ) ) {
3295                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3296                 }
3297                 $nullRevId = $nullRevision->insertOn( $dbw );
3298
3299                 # Change the name of the target page:
3300                 $dbw->update( 'page',
3301                         /* SET */ array(
3302                                 'page_touched'   => $dbw->timestamp(),
3303                                 'page_namespace' => $nt->getNamespace(),
3304                                 'page_title'     => $nt->getDBkey(),
3305                                 'page_latest'    => $nullRevId,
3306                         ),
3307                         /* WHERE */ array( 'page_id' => $oldid ),
3308                         __METHOD__
3309                 );
3310                 $nt->resetArticleID( $oldid );
3311
3312                 $article = new Article( $nt );
3313                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3314
3315                 # Recreate the redirect, this time in the other direction.
3316                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3317                         $mwRedir = MagicWord::get( 'redirect' );
3318                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3319                         $redirectArticle = new Article( $this );
3320                         $newid = $redirectArticle->insertOn( $dbw );
3321                         $redirectRevision = new Revision( array(
3322                                 'page'    => $newid,
3323                                 'comment' => $comment,
3324                                 'text'    => $redirectText ) );
3325                         $redirectRevision->insertOn( $dbw );
3326                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3327
3328                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3329
3330                         # Now, we record the link from the redirect to the new title.
3331                         # It should have no other outgoing links...
3332                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3333                         $dbw->insert( 'pagelinks',
3334                                 array(
3335                                         'pl_from'      => $newid,
3336                                         'pl_namespace' => $nt->getNamespace(),
3337                                         'pl_title'     => $nt->getDBkey() ),
3338                                 __METHOD__ );
3339                         $redirectSuppressed = false;
3340                 } else {
3341                         // Get rid of old new page entries in Special:NewPages and RC.
3342                         // Needs to be before $this->resetArticleID( 0 ).
3343                         $dbw->delete( 'recentchanges', array(
3344                                         'rc_timestamp' => $dbw->timestamp( $this->getEarliestRevTime() ),
3345                                         'rc_namespace' => $oldns,
3346                                         'rc_title' => $olddbk,
3347                                         'rc_new' => 1
3348                                 ),
3349                                 __METHOD__
3350                         );
3351
3352                         $this->resetArticleID( 0 );
3353                         $redirectSuppressed = true;
3354                 }
3355
3356                 # Log the move
3357                 $log = new LogPage( 'move' );
3358                 $logType = ( $moveOverRedirect ? 'move_redir' : 'move' );
3359                 $log->addEntry( $logType, $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3360
3361                 # Purge caches for old and new titles
3362                 if ( $moveOverRedirect ) {
3363                         # A simple purge is enough when moving over a redirect
3364                         $nt->purgeSquid();
3365                 } else {
3366                         # Purge caches as per article creation, including any pages that link to this title
3367                         Article::onArticleCreate( $nt );
3368                 }
3369                 $this->purgeSquid();
3370         }
3371
3372         /**
3373          * Move this page's subpages to be subpages of $nt
3374          *
3375          * @param $nt Title Move target
3376          * @param $auth bool Whether $wgUser's permissions should be checked
3377          * @param $reason string The reason for the move
3378          * @param $createRedirect bool Whether to create redirects from the old subpages to
3379          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3380          * @return mixed array with old page titles as keys, and strings (new page titles) or
3381          *     arrays (errors) as values, or an error array with numeric indices if no pages
3382          *     were moved
3383          */
3384         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3385                 global $wgMaximumMovedPages;
3386                 // Check permissions
3387                 if ( !$this->userCan( 'move-subpages' ) ) {
3388                         return array( 'cant-move-subpages' );
3389                 }
3390                 // Do the source and target namespaces support subpages?
3391                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3392                         return array( 'namespace-nosubpages',
3393                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3394                 }
3395                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3396                         return array( 'namespace-nosubpages',
3397                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3398                 }
3399
3400                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3401                 $retval = array();
3402                 $count = 0;
3403                 foreach ( $subpages as $oldSubpage ) {
3404                         $count++;
3405                         if ( $count > $wgMaximumMovedPages ) {
3406                                 $retval[$oldSubpage->getPrefixedTitle()] =
3407                                                 array( 'movepage-max-pages',
3408                                                         $wgMaximumMovedPages );
3409                                 break;
3410                         }
3411
3412                         // We don't know whether this function was called before
3413                         // or after moving the root page, so check both
3414                         // $this and $nt
3415                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3416                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3417                         {
3418                                 // When moving a page to a subpage of itself,
3419                                 // don't move it twice
3420                                 continue;
3421                         }
3422                         $newPageName = preg_replace(
3423                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3424                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3425                                         $oldSubpage->getDBkey() );
3426                         if ( $oldSubpage->isTalkPage() ) {
3427                                 $newNs = $nt->getTalkPage()->getNamespace();
3428                         } else {
3429                                 $newNs = $nt->getSubjectPage()->getNamespace();
3430                         }
3431                         # Bug 14385: we need makeTitleSafe because the new page names may
3432                         # be longer than 255 characters.
3433                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3434
3435                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3436                         if ( $success === true ) {
3437                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3438                         } else {
3439                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3440                         }
3441                 }
3442                 return $retval;
3443         }
3444
3445         /**
3446          * Checks if this page is just a one-rev redirect.
3447          * Adds lock, so don't use just for light purposes.
3448          *
3449          * @return Bool
3450          */
3451         public function isSingleRevRedirect() {
3452                 $dbw = wfGetDB( DB_MASTER );
3453                 # Is it a redirect?
3454                 $row = $dbw->selectRow( 'page',
3455                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3456                         $this->pageCond(),
3457                         __METHOD__,
3458                         array( 'FOR UPDATE' )
3459                 );
3460                 # Cache some fields we may want
3461                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3462                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3463                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3464                 if ( !$this->mRedirect ) {
3465                         return false;
3466                 }
3467                 # Does the article have a history?
3468                 $row = $dbw->selectField( array( 'page', 'revision' ),
3469                         'rev_id',
3470                         array( 'page_namespace' => $this->getNamespace(),
3471                                 'page_title' => $this->getDBkey(),
3472                                 'page_id=rev_page',
3473                                 'page_latest != rev_id'
3474                         ),
3475                         __METHOD__,
3476                         array( 'FOR UPDATE' )
3477                 );
3478                 # Return true if there was no history
3479                 return ( $row === false );
3480         }
3481
3482         /**
3483          * Checks if $this can be moved to a given Title
3484          * - Selects for update, so don't call it unless you mean business
3485          *
3486          * @param $nt Title the new title to check
3487          * @return Bool
3488          */
3489         public function isValidMoveTarget( $nt ) {
3490                 # Is it an existing file?
3491                 if ( $nt->getNamespace() == NS_FILE ) {
3492                         $file = wfLocalFile( $nt );
3493                         if ( $file->exists() ) {
3494                                 wfDebug( __METHOD__ . ": file exists\n" );
3495                                 return false;
3496                         }
3497                 }
3498                 # Is it a redirect with no history?
3499                 if ( !$nt->isSingleRevRedirect() ) {
3500                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3501                         return false;
3502                 }
3503                 # Get the article text
3504                 $rev = Revision::newFromTitle( $nt );
3505                 $text = $rev->getText();
3506                 # Does the redirect point to the source?
3507                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3508                 $m = array();
3509                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3510                         $redirTitle = Title::newFromText( $m[1] );
3511                         if ( !is_object( $redirTitle ) ||
3512                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3513                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3514                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3515                                 return false;
3516                         }
3517                 } else {
3518                         # Fail safe
3519                         wfDebug( __METHOD__ . ": failsafe\n" );
3520                         return false;
3521                 }
3522                 return true;
3523         }
3524
3525         /**
3526          * Can this title be added to a user's watchlist?
3527          *
3528          * @return Bool TRUE or FALSE
3529          */
3530         public function isWatchable() {
3531                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3532         }
3533
3534         /**
3535          * Get categories to which this Title belongs and return an array of
3536          * categories' names.
3537          *
3538          * @return Array of parents in the form:
3539          *        $parent => $currentarticle
3540          */
3541         public function getParentCategories() {
3542                 global $wgContLang;
3543
3544                 $data = array();
3545
3546                 $titleKey = $this->getArticleId();
3547
3548                 if ( $titleKey === 0 ) {
3549                         return $data;
3550                 }
3551
3552                 $dbr = wfGetDB( DB_SLAVE );
3553
3554                 $res = $dbr->select( 'categorylinks', '*',
3555                         array(
3556                                 'cl_from' => $titleKey,
3557                         ),
3558                         __METHOD__,
3559                         array()
3560                 );
3561
3562                 if ( $dbr->numRows( $res ) > 0 ) {
3563                         foreach ( $res as $row ) {
3564                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3565                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3566                         }
3567                 }
3568                 return $data;
3569         }
3570
3571         /**
3572          * Get a tree of parent categories
3573          *
3574          * @param $children Array with the children in the keys, to check for circular refs
3575          * @return Array Tree of parent categories
3576          */
3577         public function getParentCategoryTree( $children = array() ) {
3578                 $stack = array();
3579                 $parents = $this->getParentCategories();
3580
3581                 if ( $parents ) {
3582                         foreach ( $parents as $parent => $current ) {
3583                                 if ( array_key_exists( $parent, $children ) ) {
3584                                         # Circular reference
3585                                         $stack[$parent] = array();
3586                                 } else {
3587                                         $nt = Title::newFromText( $parent );
3588                                         if ( $nt ) {
3589                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3590                                         }
3591                                 }
3592                         }
3593                 }
3594
3595                 return $stack;
3596         }
3597
3598         /**
3599          * Get an associative array for selecting this title from
3600          * the "page" table
3601          *
3602          * @return Array suitable for the $where parameter of DB::select()
3603          */
3604         public function pageCond() {
3605                 if ( $this->mArticleID > 0 ) {
3606                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3607                         return array( 'page_id' => $this->mArticleID );
3608                 } else {
3609                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3610                 }
3611         }
3612
3613         /**
3614          * Get the revision ID of the previous revision
3615          *
3616          * @param $revId Int Revision ID. Get the revision that was before this one.
3617          * @param $flags Int Title::GAID_FOR_UPDATE
3618          * @return Int|Bool Old revision ID, or FALSE if none exists
3619          */
3620         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3621                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3622                 return $db->selectField( 'revision', 'rev_id',
3623                         array(
3624                                 'rev_page' => $this->getArticleId( $flags ),
3625                                 'rev_id < ' . intval( $revId )
3626                         ),
3627                         __METHOD__,
3628                         array( 'ORDER BY' => 'rev_id DESC' )
3629                 );
3630         }
3631
3632         /**
3633          * Get the revision ID of the next revision
3634          *
3635          * @param $revId Int Revision ID. Get the revision that was after this one.
3636          * @param $flags Int Title::GAID_FOR_UPDATE
3637          * @return Int|Bool Next revision ID, or FALSE if none exists
3638          */
3639         public function getNextRevisionID( $revId, $flags = 0 ) {
3640                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3641                 return $db->selectField( 'revision', 'rev_id',
3642                         array(
3643                                 'rev_page' => $this->getArticleId( $flags ),
3644                                 'rev_id > ' . intval( $revId )
3645                         ),
3646                         __METHOD__,
3647                         array( 'ORDER BY' => 'rev_id' )
3648                 );
3649         }
3650
3651         /**
3652          * Get the first revision of the page
3653          *
3654          * @param $flags Int Title::GAID_FOR_UPDATE
3655          * @return Revision|Null if page doesn't exist
3656          */
3657         public function getFirstRevision( $flags = 0 ) {
3658                 $pageId = $this->getArticleId( $flags );
3659                 if ( $pageId ) {
3660                         $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3661                         $row = $db->selectRow( 'revision', '*',
3662                                 array( 'rev_page' => $pageId ),
3663                                 __METHOD__,
3664                                 array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3665                         );
3666                         if ( $row ) {
3667                                 return new Revision( $row );
3668                         }
3669                 }
3670                 return null;
3671         }
3672
3673         /**
3674          * Get the oldest revision timestamp of this page
3675          *
3676          * @param $flags Int Title::GAID_FOR_UPDATE
3677          * @return String: MW timestamp
3678          */
3679         public function getEarliestRevTime( $flags = 0 ) {
3680                 $rev = $this->getFirstRevision( $flags );
3681                 return $rev ? $rev->getTimestamp() : null;
3682         }
3683
3684         /**
3685          * Check if this is a new page
3686          *
3687          * @return bool
3688          */
3689         public function isNewPage() {
3690                 $dbr = wfGetDB( DB_SLAVE );
3691                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3692         }
3693
3694         /**
3695          * Get the number of revisions between the given revision.
3696          * Used for diffs and other things that really need it.
3697          *
3698          * @param $old int|Revision Old revision or rev ID (first before range)
3699          * @param $new int|Revision New revision or rev ID (first after range)
3700          * @return Int Number of revisions between these revisions.
3701          */
3702         public function countRevisionsBetween( $old, $new ) {
3703                 if ( !( $old instanceof Revision ) ) {
3704                         $old = Revision::newFromTitle( $this, (int)$old );
3705                 }
3706                 if ( !( $new instanceof Revision ) ) {
3707                         $new = Revision::newFromTitle( $this, (int)$new );
3708                 }
3709                 if ( !$old || !$new ) {
3710                         return 0; // nothing to compare
3711                 }
3712                 $dbr = wfGetDB( DB_SLAVE );
3713                 return (int)$dbr->selectField( 'revision', 'count(*)',
3714                         array(
3715                                 'rev_page' => $this->getArticleId(),
3716                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3717                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3718                         ),
3719                         __METHOD__
3720                 );
3721         }
3722
3723         /**
3724          * Get the number of authors between the given revision IDs.
3725          * Used for diffs and other things that really need it.
3726          *
3727          * @param $old int|Revision Old revision or rev ID (first before range)
3728          * @param $new int|Revision New revision or rev ID (first after range)
3729          * @param $limit Int Maximum number of authors
3730          * @return Int Number of revision authors between these revisions.
3731          */
3732         public function countAuthorsBetween( $old, $new, $limit ) {
3733                 if ( !( $old instanceof Revision ) ) {
3734                         $old = Revision::newFromTitle( $this, (int)$old );
3735                 }
3736                 if ( !( $new instanceof Revision ) ) {
3737                         $new = Revision::newFromTitle( $this, (int)$new );
3738                 }
3739                 if ( !$old || !$new ) {
3740                         return 0; // nothing to compare
3741                 }
3742                 $dbr = wfGetDB( DB_SLAVE );
3743                 $res = $dbr->select( 'revision', 'DISTINCT rev_user_text',
3744                         array(
3745                                 'rev_page' => $this->getArticleID(),
3746                                 'rev_timestamp > ' . $dbr->addQuotes( $dbr->timestamp( $old->getTimestamp() ) ),
3747                                 'rev_timestamp < ' . $dbr->addQuotes( $dbr->timestamp( $new->getTimestamp() ) )
3748                         ), __METHOD__,
3749                         array( 'LIMIT' => $limit + 1 ) // add one so caller knows it was truncated
3750                 );
3751                 return (int)$dbr->numRows( $res );
3752         }
3753
3754         /**
3755          * Compare with another title.
3756          *
3757          * @param $title Title
3758          * @return Bool
3759          */
3760         public function equals( Title $title ) {
3761                 // Note: === is necessary for proper matching of number-like titles.
3762                 return $this->getInterwiki() === $title->getInterwiki()
3763                         && $this->getNamespace() == $title->getNamespace()
3764                         && $this->getDBkey() === $title->getDBkey();
3765         }
3766
3767         /**
3768          * Callback for usort() to do title sorts by (namespace, title)
3769          *
3770          * @param $a Title
3771          * @param $b Title
3772          *
3773          * @return Integer: result of string comparison, or namespace comparison
3774          */
3775         public static function compare( $a, $b ) {
3776                 if ( $a->getNamespace() == $b->getNamespace() ) {
3777                         return strcmp( $a->getText(), $b->getText() );
3778                 } else {
3779                         return $a->getNamespace() - $b->getNamespace();
3780                 }
3781         }
3782
3783         /**
3784          * Return a string representation of this title
3785          *
3786          * @return String representation of this title
3787          */
3788         public function __toString() {
3789                 return $this->getPrefixedText();
3790         }
3791
3792         /**
3793          * Check if page exists.  For historical reasons, this function simply
3794          * checks for the existence of the title in the page table, and will
3795          * thus return false for interwiki links, special pages and the like.
3796          * If you want to know if a title can be meaningfully viewed, you should
3797          * probably call the isKnown() method instead.
3798          *
3799          * @return Bool
3800          */
3801         public function exists() {
3802                 return $this->getArticleId() != 0;
3803         }
3804
3805         /**
3806          * Should links to this title be shown as potentially viewable (i.e. as
3807          * "bluelinks"), even if there's no record by this title in the page
3808          * table?
3809          *
3810          * This function is semi-deprecated for public use, as well as somewhat
3811          * misleadingly named.  You probably just want to call isKnown(), which
3812          * calls this function internally.
3813          *
3814          * (ISSUE: Most of these checks are cheap, but the file existence check
3815          * can potentially be quite expensive.  Including it here fixes a lot of
3816          * existing code, but we might want to add an optional parameter to skip
3817          * it and any other expensive checks.)
3818          *
3819          * @return Bool
3820          */
3821         public function isAlwaysKnown() {
3822                 if ( $this->mInterwiki != '' ) {
3823                         return true;  // any interwiki link might be viewable, for all we know
3824                 }
3825                 switch( $this->mNamespace ) {
3826                         case NS_MEDIA:
3827                         case NS_FILE:
3828                                 // file exists, possibly in a foreign repo
3829                                 return (bool)wfFindFile( $this );
3830                         case NS_SPECIAL:
3831                                 // valid special page
3832                                 return SpecialPageFactory::exists( $this->getDBkey() );
3833                         case NS_MAIN:
3834                                 // selflink, possibly with fragment
3835                                 return $this->mDbkeyform == '';
3836                         case NS_MEDIAWIKI:
3837                                 // known system message
3838                                 return $this->getDefaultMessageText() !== false;
3839                         default:
3840                                 return false;
3841                 }
3842         }
3843
3844         /**
3845          * Does this title refer to a page that can (or might) be meaningfully
3846          * viewed?  In particular, this function may be used to determine if
3847          * links to the title should be rendered as "bluelinks" (as opposed to
3848          * "redlinks" to non-existent pages).
3849          *
3850          * @return Bool
3851          */
3852         public function isKnown() {
3853                 return $this->isAlwaysKnown() || $this->exists();
3854         }
3855
3856         /**
3857          * Does this page have source text?
3858          *
3859          * @return Boolean
3860          */
3861         public function hasSourceText() {
3862                 if ( $this->exists() ) {
3863                         return true;
3864                 }
3865
3866                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3867                         // If the page doesn't exist but is a known system message, default
3868                         // message content will be displayed, same for language subpages
3869                         return $this->getDefaultMessageText() !== false;
3870                 }
3871
3872                 return false;
3873         }
3874
3875         /**
3876          * Get the default message text or false if the message doesn't exist
3877          *
3878          * @return String or false
3879          */
3880         public function getDefaultMessageText() {
3881                 global $wgContLang;
3882
3883                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
3884                         return false;
3885                 }
3886
3887                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
3888                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
3889
3890                 if ( $message->exists() ) {
3891                         return $message->plain();
3892                 } else {
3893                         return false;
3894                 }
3895         }
3896
3897         /**
3898          * Is this in a namespace that allows actual pages?
3899          *
3900          * @return Bool
3901          * @internal note -- uses hardcoded namespace index instead of constants
3902          */
3903         public function canExist() {
3904                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3905         }
3906
3907         /**
3908          * Update page_touched timestamps and send squid purge messages for
3909          * pages linking to this title. May be sent to the job queue depending
3910          * on the number of links. Typically called on create and delete.
3911          */
3912         public function touchLinks() {
3913                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3914                 $u->doUpdate();
3915
3916                 if ( $this->getNamespace() == NS_CATEGORY ) {
3917                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3918                         $u->doUpdate();
3919                 }
3920         }
3921
3922         /**
3923          * Get the last touched timestamp
3924          *
3925          * @param $db DatabaseBase: optional db
3926          * @return String last-touched timestamp
3927          */
3928         public function getTouched( $db = null ) {
3929                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3930                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3931                 return $touched;
3932         }
3933
3934         /**
3935          * Get the timestamp when this page was updated since the user last saw it.
3936          *
3937          * @param $user User
3938          * @return String|Null
3939          */
3940         public function getNotificationTimestamp( $user = null ) {
3941                 global $wgUser, $wgShowUpdatedMarker;
3942                 // Assume current user if none given
3943                 if ( !$user ) {
3944                         $user = $wgUser;
3945                 }
3946                 // Check cache first
3947                 $uid = $user->getId();
3948                 // avoid isset here, as it'll return false for null entries
3949                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
3950                         return $this->mNotificationTimestamp[$uid];
3951                 }
3952                 if ( !$uid || !$wgShowUpdatedMarker ) {
3953                         return $this->mNotificationTimestamp[$uid] = false;
3954                 }
3955                 // Don't cache too much!
3956                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3957                         $this->mNotificationTimestamp = array();
3958                 }
3959                 $dbr = wfGetDB( DB_SLAVE );
3960                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3961                         'wl_notificationtimestamp',
3962                         array( 'wl_namespace' => $this->getNamespace(),
3963                                 'wl_title' => $this->getDBkey(),
3964                                 'wl_user' => $user->getId()
3965                         ),
3966                         __METHOD__
3967                 );
3968                 return $this->mNotificationTimestamp[$uid];
3969         }
3970
3971         /**
3972          * Get the trackback URL for this page
3973          *
3974          * @return String Trackback URL
3975          */
3976         public function trackbackURL() {
3977                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3978
3979                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3980                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3981         }
3982
3983         /**
3984          * Get the trackback RDF for this page
3985          *
3986          * @return String Trackback RDF
3987          */
3988         public function trackbackRDF() {
3989                 $url = htmlspecialchars( $this->getFullURL() );
3990                 $title = htmlspecialchars( $this->getText() );
3991                 $tburl = $this->trackbackURL();
3992
3993                 // Autodiscovery RDF is placed in comments so HTML validator
3994                 // won't barf. This is a rather icky workaround, but seems
3995                 // frequently used by this kind of RDF thingy.
3996                 //
3997                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3998                 return "<!--
3999 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
4000                  xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
4001                  xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
4002 <rdf:Description
4003    rdf:about=\"$url\"
4004    dc:identifier=\"$url\"
4005    dc:title=\"$title\"
4006    trackback:ping=\"$tburl\" />
4007 </rdf:RDF>
4008 -->";
4009         }
4010
4011         /**
4012          * Generate strings used for xml 'id' names in monobook tabs
4013          *
4014          * @param $prepend string defaults to 'nstab-'
4015          * @return String XML 'id' name
4016          */
4017         public function getNamespaceKey( $prepend = 'nstab-' ) {
4018                 global $wgContLang;
4019                 // Gets the subject namespace if this title
4020                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4021                 // Checks if cononical namespace name exists for namespace
4022                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4023                         // Uses canonical namespace name
4024                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4025                 } else {
4026                         // Uses text of namespace
4027                         $namespaceKey = $this->getSubjectNsText();
4028                 }
4029                 // Makes namespace key lowercase
4030                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4031                 // Uses main
4032                 if ( $namespaceKey == '' ) {
4033                         $namespaceKey = 'main';
4034                 }
4035                 // Changes file to image for backwards compatibility
4036                 if ( $namespaceKey == 'file' ) {
4037                         $namespaceKey = 'image';
4038                 }
4039                 return $prepend . $namespaceKey;
4040         }
4041
4042         /**
4043          * Returns true if this is a special page.
4044          *
4045          * @return boolean
4046          */
4047         public function isSpecialPage() {
4048                 return $this->getNamespace() == NS_SPECIAL;
4049         }
4050
4051         /**
4052          * Returns true if this title resolves to the named special page
4053          *
4054          * @param $name String The special page name
4055          * @return boolean
4056          */
4057         public function isSpecial( $name ) {
4058                 if ( $this->getNamespace() == NS_SPECIAL ) {
4059                         list( $thisName, /* $subpage */ ) = SpecialPageFactory::resolveAlias( $this->getDBkey() );
4060                         if ( $name == $thisName ) {
4061                                 return true;
4062                         }
4063                 }
4064                 return false;
4065         }
4066
4067         /**
4068          * If the Title refers to a special page alias which is not the local default, resolve
4069          * the alias, and localise the name as necessary.  Otherwise, return $this
4070          *
4071          * @return Title
4072          */
4073         public function fixSpecialName() {
4074                 if ( $this->getNamespace() == NS_SPECIAL ) {
4075                         list( $canonicalName, /*...*/ ) = SpecialPageFactory::resolveAlias( $this->mDbkeyform );
4076                         if ( $canonicalName ) {
4077                                 $localName = SpecialPageFactory::getLocalNameFor( $canonicalName );
4078                                 if ( $localName != $this->mDbkeyform ) {
4079                                         return Title::makeTitle( NS_SPECIAL, $localName );
4080                                 }
4081                         }
4082                 }
4083                 return $this;
4084         }
4085
4086         /**
4087          * Is this Title in a namespace which contains content?
4088          * In other words, is this a content page, for the purposes of calculating
4089          * statistics, etc?
4090          *
4091          * @return Boolean
4092          */
4093         public function isContentPage() {
4094                 return MWNamespace::isContent( $this->getNamespace() );
4095         }
4096
4097         /**
4098          * Get all extant redirects to this Title
4099          *
4100          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4101          * @return Array of Title redirects to this title
4102          */
4103         public function getRedirectsHere( $ns = null ) {
4104                 $redirs = array();
4105
4106                 $dbr = wfGetDB( DB_SLAVE );
4107                 $where = array(
4108                         'rd_namespace' => $this->getNamespace(),
4109                         'rd_title' => $this->getDBkey(),
4110                         'rd_from = page_id'
4111                 );
4112                 if ( !is_null( $ns ) ) {
4113                         $where['page_namespace'] = $ns;
4114                 }
4115
4116                 $res = $dbr->select(
4117                         array( 'redirect', 'page' ),
4118                         array( 'page_namespace', 'page_title' ),
4119                         $where,
4120                         __METHOD__
4121                 );
4122
4123                 foreach ( $res as $row ) {
4124                         $redirs[] = self::newFromRow( $row );
4125                 }
4126                 return $redirs;
4127         }
4128
4129         /**
4130          * Check if this Title is a valid redirect target
4131          *
4132          * @return Bool
4133          */
4134         public function isValidRedirectTarget() {
4135                 global $wgInvalidRedirectTargets;
4136
4137                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4138                 if ( $this->isSpecial( 'Userlogout' ) ) {
4139                         return false;
4140                 }
4141
4142                 foreach ( $wgInvalidRedirectTargets as $target ) {
4143                         if ( $this->isSpecial( $target ) ) {
4144                                 return false;
4145                         }
4146                 }
4147
4148                 return true;
4149         }
4150
4151         /**
4152          * Get a backlink cache object
4153          *
4154          * @return object BacklinkCache
4155          */
4156         function getBacklinkCache() {
4157                 if ( is_null( $this->mBacklinkCache ) ) {
4158                         $this->mBacklinkCache = new BacklinkCache( $this );
4159                 }
4160                 return $this->mBacklinkCache;
4161         }
4162
4163         /**
4164          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4165          *
4166          * @return Boolean
4167          */
4168         public function canUseNoindex() {
4169                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4170
4171                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4172                         ? $wgContentNamespaces
4173                         : $wgExemptFromUserRobotsControl;
4174
4175                 return !in_array( $this->mNamespace, $bannedNamespaces );
4176
4177         }
4178
4179         /**
4180          * Returns restriction types for the current Title
4181          *
4182          * @return array applicable restriction types
4183          */
4184         public function getRestrictionTypes() {
4185                 if ( $this->getNamespace() == NS_SPECIAL ) {
4186                         return array();
4187                 }
4188
4189                 $types = self::getFilteredRestrictionTypes( $this->exists() );
4190
4191                 if ( $this->getNamespace() != NS_FILE ) {
4192                         # Remove the upload restriction for non-file titles
4193                         $types = array_diff( $types, array( 'upload' ) );
4194                 }
4195
4196                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4197
4198                 wfDebug( __METHOD__ . ': applicable restriction types for ' .
4199                         $this->getPrefixedText() . ' are ' . implode( ',', $types ) . "\n" );
4200
4201                 return $types;
4202         }
4203         /**
4204          * Get a filtered list of all restriction types supported by this wiki.
4205          * @param bool $exists True to get all restriction types that apply to
4206          * titles that do exist, False for all restriction types that apply to
4207          * titles that do not exist
4208          * @return array
4209          */
4210         public static function getFilteredRestrictionTypes( $exists = true ) {
4211                 global $wgRestrictionTypes;
4212                 $types = $wgRestrictionTypes;
4213                 if ( $exists ) {
4214                         # Remove the create restriction for existing titles
4215                         $types = array_diff( $types, array( 'create' ) );
4216                 } else {
4217                         # Only the create and upload restrictions apply to non-existing titles
4218                         $types = array_intersect( $types, array( 'create', 'upload' ) );
4219                 }
4220                 return $types;
4221         }
4222
4223         /**
4224          * Returns the raw sort key to be used for categories, with the specified
4225          * prefix.  This will be fed to Collation::getSortKey() to get a
4226          * binary sortkey that can be used for actual sorting.
4227          *
4228          * @param $prefix string The prefix to be used, specified using
4229          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4230          *   prefix.
4231          * @return string
4232          */
4233         public function getCategorySortkey( $prefix = '' ) {
4234                 $unprefixed = $this->getText();
4235                 if ( $prefix !== '' ) {
4236                         # Separate with a line feed, so the unprefixed part is only used as
4237                         # a tiebreaker when two pages have the exact same prefix.
4238                         # In UCA, tab is the only character that can sort above LF
4239                         # so we strip both of them from the original prefix.
4240                         $prefix = strtr( $prefix, "\n\t", '  ' );
4241                         return "$prefix\n$unprefixed";
4242                 }
4243                 return $unprefixed;
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 }