includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  * @file
   5  */
   6
   7 /**
   8  * @todo:  determine if it is really necessary to load this.  Appears to be left over from pre-autoloader versions, and
   9  *   is only really needed to provide access to constant UTF8_REPLACEMENT, which actually resides in UtfNormalDefines.php
  10  *   and is loaded by UtfNormalUtil.php, which is loaded by UtfNormal.php.
  11  */
  12 if ( !class_exists( 'UtfNormal' ) ) {
  13         require_once( dirname( __FILE__ ) . '/normal/UtfNormal.php' );
  14 }
  15
  16 /**
  17  * @deprecated This used to be a define, but was moved to
  18  * Title::GAID_FOR_UPDATE in 1.17. This will probably be removed in 1.18
  19  */
  20 define( 'GAID_FOR_UPDATE', Title::GAID_FOR_UPDATE );
  21
  22 /**
  23  * Represents a title within MediaWiki.
  24  * Optionally may contain an interwiki designation or namespace.
  25  * @note This class can fetch various kinds of data from the database;
  26  *       however, it does so inefficiently.
  27  *
  28  * @internal documentation reviewed 15 Mar 2010
  29  */
  30 class Title {
  31         /** @name Static cache variables */
  32         // @{
  33         static private $titleCache = array();
  34         // @}
  35
  36         /**
  37          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  38          * commonly used titles. On a batch operation this can become a memory leak
  39          * if not bounded. After hitting this many titles reset the cache.
  40          */
  41         const CACHE_MAX = 1000;
  42
  43         /**
  44          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  45          * to use the master DB
  46          */
  47         const GAID_FOR_UPDATE = 1;
  48
  49
  50         /**
  51          * @name Private member variables
  52          * Please use the accessor functions instead.
  53          * @private
  54          */
  55         // @{
  56
  57         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  58         var $mUrlform = '';               // /< URL-encoded form of the main part
  59         var $mDbkeyform = '';             // /< Main part with underscores
  60         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  61         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  62         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  63         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  64         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  65         var $mLatestID = false;           // /< ID of most recent revision
  66         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  67         var $mOldRestrictions = false;
  68         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  69         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  70         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  71         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  72         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  73         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  74         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  75         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  76         # Don't change the following default, NS_MAIN is hardcoded in several
  77         # places.  See bug 696.
  78         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  79                                                                           # Zero except in {{transclusion}} tags
  80         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  81         var $mLength = -1;                // /< The page length, 0 for special pages
  82         var $mRedirect = null;            // /< Is the article at this title a redirect?
  83         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  84         var $mBacklinkCache = null;       // /< Cache of links to this title
  85         // @}
  86
  87
  88         /**
  89          * Constructor
  90          * @private
  91          */
  92         /* private */ function __construct() { }
  93
  94         /**
  95          * Create a new Title from a prefixed DB key
  96          *
  97          * @param $key String the database key, which has underscores
  98          *      instead of spaces, possibly including namespace and
  99          *      interwiki prefixes
 100          * @return Title, or NULL on an error
 101          */
 102         public static function newFromDBkey( $key ) {
 103                 $t = new Title();
 104                 $t->mDbkeyform = $key;
 105                 if ( $t->secureAndSplit() ) {
 106                         return $t;
 107                 } else {
 108                         return null;
 109                 }
 110         }
 111
 112         /**
 113          * Create a new Title from text, such as what one would find in a link. De-
 114          * codes any HTML entities in the text.
 115          *
 116          * @param $text String the link text; spaces, prefixes, and an
 117          *   initial ':' indicating the main namespace are accepted.
 118          * @param $defaultNamespace Int the namespace to use if none is speci-
 119          *   fied by a prefix.  If you want to force a specific namespace even if
 120          *   $text might begin with a namespace prefix, use makeTitle() or
 121          *   makeTitleSafe().
 122          * @return Title, or null on an error.
 123          */
 124         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 125                 if ( is_object( $text ) ) {
 126                         throw new MWException( 'Title::newFromText given an object' );
 127                 }
 128
 129                 /**
 130                  * Wiki pages often contain multiple links to the same page.
 131                  * Title normalization and parsing can become expensive on
 132                  * pages with many links, so we can save a little time by
 133                  * caching them.
 134                  *
 135                  * In theory these are value objects and won't get changed...
 136                  */
 137                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 138                         return Title::$titleCache[$text];
 139                 }
 140
 141                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 142                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 143
 144                 $t = new Title();
 145                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 146                 $t->mDefaultNamespace = $defaultNamespace;
 147
 148                 static $cachedcount = 0 ;
 149                 if ( $t->secureAndSplit() ) {
 150                         if ( $defaultNamespace == NS_MAIN ) {
 151                                 if ( $cachedcount >= self::CACHE_MAX ) {
 152                                         # Avoid memory leaks on mass operations...
 153                                         Title::$titleCache = array();
 154                                         $cachedcount = 0;
 155                                 }
 156                                 $cachedcount++;
 157                                 Title::$titleCache[$text] =& $t;
 158                         }
 159                         return $t;
 160                 } else {
 161                         $ret = null;
 162                         return $ret;
 163                 }
 164         }
 165
 166         /**
 167          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 168          *
 169          * Example of wrong and broken code:
 170          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 171          *
 172          * Example of right code:
 173          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 174          *
 175          * Create a new Title from URL-encoded text. Ensures that
 176          * the given title's length does not exceed the maximum.
 177          *
 178          * @param $url String the title, as might be taken from a URL
 179          * @return Title the new object, or NULL on an error
 180          */
 181         public static function newFromURL( $url ) {
 182                 global $wgLegalTitleChars;
 183                 $t = new Title();
 184
 185                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 186                 # but some URLs used it as a space replacement and they still come
 187                 # from some external search tools.
 188                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 189                         $url = str_replace( '+', ' ', $url );
 190                 }
 191
 192                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 193                 if ( $t->secureAndSplit() ) {
 194                         return $t;
 195                 } else {
 196                         return null;
 197                 }
 198         }
 199
 200         /**
 201          * Create a new Title from an article ID
 202          *
 203          * @param $id Int the page_id corresponding to the Title to create
 204          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 205          * @return Title the new object, or NULL on an error
 206          */
 207         public static function newFromID( $id, $flags = 0 ) {
 208                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 209                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 210                 if ( $row !== false ) {
 211                         $title = Title::newFromRow( $row );
 212                 } else {
 213                         $title = null;
 214                 }
 215                 return $title;
 216         }
 217
 218         /**
 219          * Make an array of titles from an array of IDs
 220          *
 221          * @param $ids Array of Int Array of IDs
 222          * @return Array of Titles
 223          */
 224         public static function newFromIDs( $ids ) {
 225                 if ( !count( $ids ) ) {
 226                         return array();
 227                 }
 228                 $dbr = wfGetDB( DB_SLAVE );
 229
 230                 $res = $dbr->select(
 231                         'page',
 232                         array(
 233                                 'page_namespace', 'page_title', 'page_id',
 234                                 'page_len', 'page_is_redirect', 'page_latest',
 235                         ),
 236                         array( 'page_id' => $ids ),
 237                         __METHOD__
 238                 );
 239
 240                 $titles = array();
 241                 foreach ( $res as $row ) {
 242                         $titles[] = Title::newFromRow( $row );
 243                 }
 244                 return $titles;
 245         }
 246
 247         /**
 248          * Make a Title object from a DB row
 249          *
 250          * @param $row Object database row (needs at least page_title,page_namespace)
 251          * @return Title corresponding Title
 252          */
 253         public static function newFromRow( $row ) {
 254                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 255
 256                 $t->mArticleID = isset( $row->page_id ) ? intval( $row->page_id ) : -1;
 257                 $t->mLength = isset( $row->page_len ) ? intval( $row->page_len ) : -1;
 258                 $t->mRedirect = isset( $row->page_is_redirect ) ? (bool)$row->page_is_redirect : null;
 259                 $t->mLatestID = isset( $row->page_latest ) ? intval( $row->page_latest ) : false;
 260
 261                 return $t;
 262         }
 263
 264         /**
 265          * Create a new Title from a namespace index and a DB key.
 266          * It's assumed that $ns and $title are *valid*, for instance when
 267          * they came directly from the database or a special page name.
 268          * For convenience, spaces are converted to underscores so that
 269          * eg user_text fields can be used directly.
 270          *
 271          * @param $ns Int the namespace of the article
 272          * @param $title String the unprefixed database key form
 273          * @param $fragment String the link fragment (after the "#")
 274          * @param $interwiki String the interwiki prefix
 275          * @return Title the new object
 276          */
 277         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 278                 $t = new Title();
 279                 $t->mInterwiki = $interwiki;
 280                 $t->mFragment = $fragment;
 281                 $t->mNamespace = $ns = intval( $ns );
 282                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 283                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 284                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 285                 $t->mTextform = str_replace( '_', ' ', $title );
 286                 return $t;
 287         }
 288
 289         /**
 290          * Create a new Title from a namespace index and a DB key.
 291          * The parameters will be checked for validity, which is a bit slower
 292          * than makeTitle() but safer for user-provided data.
 293          *
 294          * @param $ns Int the namespace of the article
 295          * @param $title String database key form
 296          * @param $fragment String the link fragment (after the "#")
 297          * @param $interwiki String interwiki prefix
 298          * @return Title the new object, or NULL on an error
 299          */
 300         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 301                 $t = new Title();
 302                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 303                 if ( $t->secureAndSplit() ) {
 304                         return $t;
 305                 } else {
 306                         return null;
 307                 }
 308         }
 309
 310         /**
 311          * Create a new Title for the Main Page
 312          *
 313          * @return Title the new object
 314          */
 315         public static function newMainPage() {
 316                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 317                 // Don't give fatal errors if the message is broken
 318                 if ( !$title ) {
 319                         $title = Title::newFromText( 'Main Page' );
 320                 }
 321                 return $title;
 322         }
 323
 324         /**
 325          * Extract a redirect destination from a string and return the
 326          * Title, or null if the text doesn't contain a valid redirect
 327          * This will only return the very next target, useful for
 328          * the redirect table and other checks that don't need full recursion
 329          *
 330          * @param $text String: Text with possible redirect
 331          * @return Title: The corresponding Title
 332          */
 333         public static function newFromRedirect( $text ) {
 334                 return self::newFromRedirectInternal( $text );
 335         }
 336
 337         /**
 338          * Extract a redirect destination from a string and return the
 339          * Title, or null if the text doesn't contain a valid redirect
 340          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 341          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 342          *
 343          * @param $text String Text with possible redirect
 344          * @return Title
 345          */
 346         public static function newFromRedirectRecurse( $text ) {
 347                 $titles = self::newFromRedirectArray( $text );
 348                 return $titles ? array_pop( $titles ) : null;
 349         }
 350
 351         /**
 352          * Extract a redirect destination from a string and return an
 353          * array of Titles, or null if the text doesn't contain a valid redirect
 354          * The last element in the array is the final destination after all redirects
 355          * have been resolved (up to $wgMaxRedirects times)
 356          *
 357          * @param $text String Text with possible redirect
 358          * @return Array of Titles, with the destination last
 359          */
 360         public static function newFromRedirectArray( $text ) {
 361                 global $wgMaxRedirects;
 362                 // are redirects disabled?
 363                 if ( $wgMaxRedirects < 1 ) {
 364                         return null;
 365                 }
 366                 $title = self::newFromRedirectInternal( $text );
 367                 if ( is_null( $title ) ) {
 368                         return null;
 369                 }
 370                 // recursive check to follow double redirects
 371                 $recurse = $wgMaxRedirects;
 372                 $titles = array( $title );
 373                 while ( --$recurse > 0 ) {
 374                         if ( $title->isRedirect() ) {
 375                                 $article = new Article( $title, 0 );
 376                                 $newtitle = $article->getRedirectTarget();
 377                         } else {
 378                                 break;
 379                         }
 380                         // Redirects to some special pages are not permitted
 381                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 382                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 383                                 $title = $newtitle;
 384                                 $titles[] = $newtitle;
 385                         } else {
 386                                 break;
 387                         }
 388                 }
 389                 return $titles;
 390         }
 391
 392         /**
 393          * Really extract the redirect destination
 394          * Do not call this function directly, use one of the newFromRedirect* functions above
 395          *
 396          * @param $text String Text with possible redirect
 397          * @return Title
 398          */
 399         protected static function newFromRedirectInternal( $text ) {
 400                 $redir = MagicWord::get( 'redirect' );
 401                 $text = trim( $text );
 402                 if ( $redir->matchStartAndRemove( $text ) ) {
 403                         // Extract the first link and see if it's usable
 404                         // Ensure that it really does come directly after #REDIRECT
 405                         // Some older redirects included a colon, so don't freak about that!
 406                         $m = array();
 407                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 408                                 // Strip preceding colon used to "escape" categories, etc.
 409                                 // and URL-decode links
 410                                 if ( strpos( $m[1], '%' ) !== false ) {
 411                                         // Match behavior of inline link parsing here;
 412                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 413                                 }
 414                                 $title = Title::newFromText( $m[1] );
 415                                 // If the title is a redirect to bad special pages or is invalid, return null
 416                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 417                                         return null;
 418                                 }
 419                                 return $title;
 420                         }
 421                 }
 422                 return null;
 423         }
 424
 425 # ----------------------------------------------------------------------------
 426 #       Static functions
 427 # ----------------------------------------------------------------------------
 428
 429         /**
 430          * Get the prefixed DB key associated with an ID
 431          *
 432          * @param $id Int the page_id of the article
 433          * @return Title an object representing the article, or NULL if no such article was found
 434          */
 435         public static function nameOf( $id ) {
 436                 $dbr = wfGetDB( DB_SLAVE );
 437
 438                 $s = $dbr->selectRow(
 439                         'page',
 440                         array( 'page_namespace', 'page_title' ),
 441                         array( 'page_id' => $id ),
 442                         __METHOD__
 443                 );
 444                 if ( $s === false ) {
 445                         return null;
 446                 }
 447
 448                 $n = self::makeName( $s->page_namespace, $s->page_title );
 449                 return $n;
 450         }
 451
 452         /**
 453          * Get a regex character class describing the legal characters in a link
 454          *
 455          * @return String the list of characters, not delimited
 456          */
 457         public static function legalChars() {
 458                 global $wgLegalTitleChars;
 459                 return $wgLegalTitleChars;
 460         }
 461
 462         /**
 463          * Get a string representation of a title suitable for
 464          * including in a search index
 465          *
 466          * @param $ns Int a namespace index
 467          * @param $title String text-form main part
 468          * @return String a stripped-down title string ready for the search index
 469          */
 470         public static function indexTitle( $ns, $title ) {
 471                 global $wgContLang;
 472
 473                 $lc = SearchEngine::legalSearchChars() . '&#;';
 474                 $t = $wgContLang->normalizeForSearch( $title );
 475                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 476                 $t = $wgContLang->lc( $t );
 477
 478                 # Handle 's, s'
 479                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 480                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 481
 482                 $t = preg_replace( "/\\s+/", ' ', $t );
 483
 484                 if ( $ns == NS_FILE ) {
 485                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 486                 }
 487                 return trim( $t );
 488         }
 489
 490         /**
 491          * Make a prefixed DB key from a DB key and a namespace index
 492          *
 493          * @param $ns Int numerical representation of the namespace
 494          * @param $title String the DB key form the title
 495          * @param $fragment String The link fragment (after the "#")
 496          * @param $interwiki String The interwiki prefix
 497          * @return String the prefixed form of the title
 498          */
 499         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 500                 global $wgContLang;
 501
 502                 $namespace = $wgContLang->getNsText( $ns );
 503                 $name = $namespace == '' ? $title : "$namespace:$title";
 504                 if ( strval( $interwiki ) != '' ) {
 505                         $name = "$interwiki:$name";
 506                 }
 507                 if ( strval( $fragment ) != '' ) {
 508                         $name .= '#' . $fragment;
 509                 }
 510                 return $name;
 511         }
 512
 513         /**
 514          * Determine whether the object refers to a page within
 515          * this project.
 516          *
 517          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 518          */
 519         public function isLocal() {
 520                 if ( $this->mInterwiki != '' ) {
 521                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 522                 } else {
 523                         return true;
 524                 }
 525         }
 526
 527         /**
 528          * Determine whether the object refers to a page within
 529          * this project and is transcludable.
 530          *
 531          * @return Bool TRUE if this is transcludable
 532          */
 533         public function isTrans() {
 534                 if ( $this->mInterwiki == '' ) {
 535                         return false;
 536                 }
 537
 538                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 539         }
 540
 541         /**
 542          * Returns the DB name of the distant wiki which owns the object.
 543          *
 544          * @return String the DB name
 545          */
 546         public function getTransWikiID() {
 547                 if ( $this->mInterwiki == '' ) {
 548                         return false;
 549                 }
 550
 551                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 552         }
 553
 554         /**
 555          * Escape a text fragment, say from a link, for a URL
 556          *
 557          * @param $fragment string containing a URL or link fragment (after the "#")
 558          * @return String: escaped string
 559          */
 560         static function escapeFragmentForURL( $fragment ) {
 561                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 562                 # fragments appear not to work in IE (at least up to 7) or in at least
 563                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 564                 # to care if they aren't encoded.
 565                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 566         }
 567
 568 # ----------------------------------------------------------------------------
 569 #       Other stuff
 570 # ----------------------------------------------------------------------------
 571
 572         /** Simple accessors */
 573         /**
 574          * Get the text form (spaces not underscores) of the main part
 575          *
 576          * @return String Main part of the title
 577          */
 578         public function getText() { return $this->mTextform; }
 579
 580         /**
 581          * Get the URL-encoded form of the main part
 582          *
 583          * @return String Main part of the title, URL-encoded
 584          */
 585         public function getPartialURL() { return $this->mUrlform; }
 586
 587         /**
 588          * Get the main part with underscores
 589          *
 590          * @return String: Main part of the title, with underscores
 591          */
 592         public function getDBkey() { return $this->mDbkeyform; }
 593
 594         /**
 595          * Get the namespace index, i.e. one of the NS_xxxx constants.
 596          *
 597          * @return Integer: Namespace index
 598          */
 599         public function getNamespace() { return $this->mNamespace; }
 600
 601         /**
 602          * Get the namespace text
 603          *
 604          * @return String: Namespace text
 605          */
 606         public function getNsText() {
 607                 global $wgContLang;
 608
 609                 if ( $this->mInterwiki != '' ) {
 610                         // This probably shouldn't even happen. ohh man, oh yuck.
 611                         // But for interwiki transclusion it sometimes does.
 612                         // Shit. Shit shit shit.
 613                         //
 614                         // Use the canonical namespaces if possible to try to
 615                         // resolve a foreign namespace.
 616                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 617                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 618                         }
 619                 }
 620                 return $wgContLang->getNsText( $this->mNamespace );
 621         }
 622
 623         /**
 624          * Get the DB key with the initial letter case as specified by the user
 625          *
 626          * @return String DB key
 627          */
 628         function getUserCaseDBKey() {
 629                 return $this->mUserCaseDBKey;
 630         }
 631
 632         /**
 633          * Get the namespace text of the subject (rather than talk) page
 634          *
 635          * @return String Namespace text
 636          */
 637         public function getSubjectNsText() {
 638                 global $wgContLang;
 639                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 640         }
 641
 642         /**
 643          * Get the namespace text of the talk page
 644          *
 645          * @return String Namespace text
 646          */
 647         public function getTalkNsText() {
 648                 global $wgContLang;
 649                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 650         }
 651
 652         /**
 653          * Could this title have a corresponding talk page?
 654          *
 655          * @return Bool TRUE or FALSE
 656          */
 657         public function canTalk() {
 658                 return( MWNamespace::canTalk( $this->mNamespace ) );
 659         }
 660
 661         /**
 662          * Get the interwiki prefix (or null string)
 663          *
 664          * @return String Interwiki prefix
 665          */
 666         public function getInterwiki() { return $this->mInterwiki; }
 667
 668         /**
 669          * Get the Title fragment (i.e.\ the bit after the #) in text form
 670          *
 671          * @return String Title fragment
 672          */
 673         public function getFragment() { return $this->mFragment; }
 674
 675         /**
 676          * Get the fragment in URL form, including the "#" character if there is one
 677          * @return String Fragment in URL form
 678          */
 679         public function getFragmentForURL() {
 680                 if ( $this->mFragment == '' ) {
 681                         return '';
 682                 } else {
 683                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 684                 }
 685         }
 686
 687         /**
 688          * Get the default namespace index, for when there is no namespace
 689          *
 690          * @return Int Default namespace index
 691          */
 692         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 693
 694         /**
 695          * Get title for search index
 696          *
 697          * @return String a stripped-down title string ready for the
 698          *  search index
 699          */
 700         public function getIndexTitle() {
 701                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 702         }
 703
 704         /**
 705          * Get the prefixed database key form
 706          *
 707          * @return String the prefixed title, with underscores and
 708          *  any interwiki and namespace prefixes
 709          */
 710         public function getPrefixedDBkey() {
 711                 $s = $this->prefix( $this->mDbkeyform );
 712                 $s = str_replace( ' ', '_', $s );
 713                 return $s;
 714         }
 715
 716         /**
 717          * Get the prefixed title with spaces.
 718          * This is the form usually used for display
 719          *
 720          * @return String the prefixed title, with spaces
 721          */
 722         public function getPrefixedText() {
 723                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 724                         $s = $this->prefix( $this->mTextform );
 725                         $s = str_replace( '_', ' ', $s );
 726                         $this->mPrefixedText = $s;
 727                 }
 728                 return $this->mPrefixedText;
 729         }
 730
 731         /**
 732          * Get the prefixed title with spaces, plus any fragment
 733          * (part beginning with '#')
 734          *
 735          * @return String the prefixed title, with spaces and the fragment, including '#'
 736          */
 737         public function getFullText() {
 738                 $text = $this->getPrefixedText();
 739                 if ( $this->mFragment != '' ) {
 740                         $text .= '#' . $this->mFragment;
 741                 }
 742                 return $text;
 743         }
 744
 745         /**
 746          * Get the base name, i.e. the leftmost parts before the /
 747          *
 748          * @return String Base name
 749          */
 750         public function getBaseText() {
 751                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 752                         return $this->getText();
 753                 }
 754
 755                 $parts = explode( '/', $this->getText() );
 756                 # Don't discard the real title if there's no subpage involved
 757                 if ( count( $parts ) > 1 ) {
 758                         unset( $parts[count( $parts ) - 1] );
 759                 }
 760                 return implode( '/', $parts );
 761         }
 762
 763         /**
 764          * Get the lowest-level subpage name, i.e. the rightmost part after /
 765          *
 766          * @return String Subpage name
 767          */
 768         public function getSubpageText() {
 769                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 770                         return( $this->mTextform );
 771                 }
 772                 $parts = explode( '/', $this->mTextform );
 773                 return( $parts[count( $parts ) - 1] );
 774         }
 775
 776         /**
 777          * Get a URL-encoded form of the subpage text
 778          *
 779          * @return String URL-encoded subpage name
 780          */
 781         public function getSubpageUrlForm() {
 782                 $text = $this->getSubpageText();
 783                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 784                 return( $text );
 785         }
 786
 787         /**
 788          * Get a URL-encoded title (not an actual URL) including interwiki
 789          *
 790          * @return String the URL-encoded form
 791          */
 792         public function getPrefixedURL() {
 793                 $s = $this->prefix( $this->mDbkeyform );
 794                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 795                 return $s;
 796         }
 797
 798         /**
 799          * Get a real URL referring to this title, with interwiki link and
 800          * fragment
 801          *
 802          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 803          *   links. Can be specified as an associative array as well, e.g.,
 804          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 805          * @param $variant String language variant of url (for sr, zh..)
 806          * @return String the URL
 807          */
 808         public function getFullURL( $query = '', $variant = false ) {
 809                 global $wgServer, $wgRequest;
 810
 811                 if ( is_array( $query ) ) {
 812                         $query = wfArrayToCGI( $query );
 813                 }
 814
 815                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 816                 if ( !$interwiki ) {
 817                         $url = $this->getLocalURL( $query, $variant );
 818
 819                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 820                         // Correct fix would be to move the prepending elsewhere.
 821                         if ( $wgRequest->getVal( 'action' ) != 'render' ) {
 822                                 $url = $wgServer . $url;
 823                         }
 824                 } else {
 825                         $baseUrl = $interwiki->getURL();
 826
 827                         $namespace = wfUrlencode( $this->getNsText() );
 828                         if ( $namespace != '' ) {
 829                                 # Can this actually happen? Interwikis shouldn't be parsed.
 830                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 831                                 $namespace .= ':';
 832                         }
 833                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 834                         $url = wfAppendQuery( $url, $query );
 835                 }
 836
 837                 # Finally, add the fragment.
 838                 $url .= $this->getFragmentForURL();
 839
 840                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 841                 return $url;
 842         }
 843
 844         /**
 845          * Get a URL with no fragment or server name.  If this page is generated
 846          * with action=render, $wgServer is prepended.
 847          *
 848          * @param $query Mixed: an optional query string; if not specified,
 849          *   $wgArticlePath will be used.  Can be specified as an associative array
 850          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 851          *   URL-escaped).
 852          * @param $variant String language variant of url (for sr, zh..)
 853          * @return String the URL
 854          */
 855         public function getLocalURL( $query = '', $variant = false ) {
 856                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 857                 global $wgVariantArticlePath, $wgContLang;
 858
 859                 if ( is_array( $query ) ) {
 860                         $query = wfArrayToCGI( $query );
 861                 }
 862
 863                 if ( $this->isExternal() ) {
 864                         $url = $this->getFullURL();
 865                         if ( $query ) {
 866                                 // This is currently only used for edit section links in the
 867                                 // context of interwiki transclusion. In theory we should
 868                                 // append the query to the end of any existing query string,
 869                                 // but interwiki transclusion is already broken in that case.
 870                                 $url .= "?$query";
 871                         }
 872                 } else {
 873                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 874                         if ( $query == '' ) {
 875                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 876                                         if ( !$wgVariantArticlePath ) {
 877                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 878                                         } else {
 879                                                 $variantArticlePath = $wgVariantArticlePath;
 880                                         }
 881                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 882                                         $url = str_replace( '$1', $dbkey, $url  );
 883                                 } else {
 884                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 885                                 }
 886                         } else {
 887                                 global $wgActionPaths;
 888                                 $url = false;
 889                                 $matches = array();
 890                                 if ( !empty( $wgActionPaths ) &&
 891                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 892                                 {
 893                                         $action = urldecode( $matches[2] );
 894                                         if ( isset( $wgActionPaths[$action] ) ) {
 895                                                 $query = $matches[1];
 896                                                 if ( isset( $matches[4] ) ) {
 897                                                         $query .= $matches[4];
 898                                                 }
 899                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 900                                                 if ( $query != '' ) {
 901                                                         $url = wfAppendQuery( $url, $query );
 902                                                 }
 903                                         }
 904                                 }
 905                                 if ( $url === false ) {
 906                                         if ( $query == '-' ) {
 907                                                 $query = '';
 908                                         }
 909                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 910                                 }
 911                         }
 912
 913                         // FIXME: this causes breakage in various places when we
 914                         // actually expected a local URL and end up with dupe prefixes.
 915                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 916                                 $url = $wgServer . $url;
 917                         }
 918                 }
 919                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 920                 return $url;
 921         }
 922
 923         /**
 924          * Get a URL that's the simplest URL that will be valid to link, locally,
 925          * to the current Title.  It includes the fragment, but does not include
 926          * the server unless action=render is used (or the link is external).  If
 927          * there's a fragment but the prefixed text is empty, we just return a link
 928          * to the fragment.
 929          *
 930          * The result obviously should not be URL-escaped, but does need to be
 931          * HTML-escaped if it's being output in HTML.
 932          *
 933          * @param $query Array of Strings An associative array of key => value pairs for the
 934          *   query string.  Keys and values will be escaped.
 935          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 936          *   for external links.  Default is "false" (same variant as current page,
 937          *   for anonymous users).
 938          * @return String the URL
 939          */
 940         public function getLinkUrl( $query = array(), $variant = false ) {
 941                 wfProfileIn( __METHOD__ );
 942                 if ( $this->isExternal() ) {
 943                         $ret = $this->getFullURL( $query );
 944                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 945                         $ret = $this->getFragmentForURL();
 946                 } else {
 947                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 948                 }
 949                 wfProfileOut( __METHOD__ );
 950                 return $ret;
 951         }
 952
 953         /**
 954          * Get an HTML-escaped version of the URL form, suitable for
 955          * using in a link, without a server name or fragment
 956          *
 957          * @param $query String an optional query string
 958          * @return String the URL
 959          */
 960         public function escapeLocalURL( $query = '' ) {
 961                 return htmlspecialchars( $this->getLocalURL( $query ) );
 962         }
 963
 964         /**
 965          * Get an HTML-escaped version of the URL form, suitable for
 966          * using in a link, including the server name and fragment
 967          *
 968          * @param $query String an optional query string
 969          * @return String the URL
 970          */
 971         public function escapeFullURL( $query = '' ) {
 972                 return htmlspecialchars( $this->getFullURL( $query ) );
 973         }
 974
 975         /**
 976          * Get the URL form for an internal link.
 977          * - Used in various Squid-related code, in case we have a different
 978          * internal hostname for the server from the exposed one.
 979          *
 980          * @param $query String an optional query string
 981          * @param $variant String language variant of url (for sr, zh..)
 982          * @return String the URL
 983          */
 984         public function getInternalURL( $query = '', $variant = false ) {
 985                 global $wgInternalServer;
 986                 $url = $wgInternalServer . $this->getLocalURL( $query, $variant );
 987                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
 988                 return $url;
 989         }
 990
 991         /**
 992          * Get the edit URL for this Title
 993          *
 994          * @return String the URL, or a null string if this is an
 995          *  interwiki link
 996          */
 997         public function getEditURL() {
 998                 if ( $this->mInterwiki != '' ) {
 999                         return '';
1000                 }
1001                 $s = $this->getLocalURL( 'action=edit' );
1002
1003                 return $s;
1004         }
1005
1006         /**
1007          * Get the HTML-escaped displayable text form.
1008          * Used for the title field in <a> tags.
1009          *
1010          * @return String the text, including any prefixes
1011          */
1012         public function getEscapedText() {
1013                 return htmlspecialchars( $this->getPrefixedText() );
1014         }
1015
1016         /**
1017          * Is this Title interwiki?
1018          *
1019          * @return Bool
1020          */
1021         public function isExternal() {
1022                 return ( $this->mInterwiki != '' );
1023         }
1024
1025         /**
1026          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1027          *
1028          * @param $action String Action to check (default: edit)
1029          * @return Bool
1030          */
1031         public function isSemiProtected( $action = 'edit' ) {
1032                 if ( $this->exists() ) {
1033                         $restrictions = $this->getRestrictions( $action );
1034                         if ( count( $restrictions ) > 0 ) {
1035                                 foreach ( $restrictions as $restriction ) {
1036                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1037                                                 return false;
1038                                         }
1039                                 }
1040                         } else {
1041                                 # Not protected
1042                                 return false;
1043                         }
1044                         return true;
1045                 } else {
1046                         # If it doesn't exist, it can't be protected
1047                         return false;
1048                 }
1049         }
1050
1051         /**
1052          * Does the title correspond to a protected article?
1053          *
1054          * @param $action String the action the page is protected from,
1055          * by default checks all actions.
1056          * @return Bool
1057          */
1058         public function isProtected( $action = '' ) {
1059                 global $wgRestrictionLevels;
1060
1061                 $restrictionTypes = $this->getRestrictionTypes();
1062
1063                 # Special pages have inherent protection
1064                 if( $this->getNamespace() == NS_SPECIAL ) {
1065                         return true;
1066                 }
1067
1068                 # Check regular protection levels
1069                 foreach ( $restrictionTypes as $type ) {
1070                         if ( $action == $type || $action == '' ) {
1071                                 $r = $this->getRestrictions( $type );
1072                                 foreach ( $wgRestrictionLevels as $level ) {
1073                                         if ( in_array( $level, $r ) && $level != '' ) {
1074                                                 return true;
1075                                         }
1076                                 }
1077                         }
1078                 }
1079
1080                 return false;
1081         }
1082
1083         /**
1084          * Is this a conversion table for the LanguageConverter?
1085          *
1086          * @return Bool
1087          */
1088         public function isConversionTable() {
1089                 if(
1090                         $this->getNamespace() == NS_MEDIAWIKI &&
1091                         strpos( $this->getText(), 'Conversiontable' ) !== false
1092                 )
1093                 {
1094                         return true;
1095                 }
1096
1097                 return false;
1098         }
1099
1100         /**
1101          * Is $wgUser watching this page?
1102          *
1103          * @return Bool
1104          */
1105         public function userIsWatching() {
1106                 global $wgUser;
1107
1108                 if ( is_null( $this->mWatched ) ) {
1109                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1110                                 $this->mWatched = false;
1111                         } else {
1112                                 $this->mWatched = $wgUser->isWatched( $this );
1113                         }
1114                 }
1115                 return $this->mWatched;
1116         }
1117
1118         /**
1119          * Can $wgUser perform $action on this page?
1120          * This skips potentially expensive cascading permission checks
1121          * as well as avoids expensive error formatting
1122          *
1123          * Suitable for use for nonessential UI controls in common cases, but
1124          * _not_ for functional access control.
1125          *
1126          * May provide false positives, but should never provide a false negative.
1127          *
1128          * @param $action String action that permission needs to be checked for
1129          * @return Bool
1130          */
1131         public function quickUserCan( $action ) {
1132                 return $this->userCan( $action, false );
1133         }
1134
1135         /**
1136          * Determines if $user is unable to edit this page because it has been protected
1137          * by $wgNamespaceProtection.
1138          *
1139          * @param $user User object, $wgUser will be used if not passed
1140          * @return Bool
1141          */
1142         public function isNamespaceProtected( User $user = null ) {
1143                 global $wgNamespaceProtection;
1144
1145                 if ( $user === null ) {
1146                         global $wgUser;
1147                         $user = $wgUser;
1148                 }
1149
1150                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1151                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1152                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1153                                         return true;
1154                                 }
1155                         }
1156                 }
1157                 return false;
1158         }
1159
1160         /**
1161          * Can $wgUser perform $action on this page?
1162          *
1163          * @param $action String action that permission needs to be checked for
1164          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1165          * @return Bool
1166          */
1167         public function userCan( $action, $doExpensiveQueries = true ) {
1168                 global $wgUser;
1169                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1170         }
1171
1172         /**
1173          * Can $user perform $action on this page?
1174          *
1175          * FIXME: This *does not* check throttles (User::pingLimiter()).
1176          *
1177          * @param $action String action that permission needs to be checked for
1178          * @param $user User to check
1179          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1180          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1181          * @return Array of arguments to wfMsg to explain permissions problems.
1182          */
1183         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1184                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1185
1186                 // Remove the errors being ignored.
1187                 foreach ( $errors as $index => $error ) {
1188                         $error_key = is_array( $error ) ? $error[0] : $error;
1189
1190                         if ( in_array( $error_key, $ignoreErrors ) ) {
1191                                 unset( $errors[$index] );
1192                         }
1193                 }
1194
1195                 return $errors;
1196         }
1197
1198         /**
1199          * Permissions checks that fail most often, and which are easiest to test.
1200          *
1201          * @param $action String the action to check
1202          * @param $user User user to check
1203          * @param $errors Array list of current errors
1204          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1205          * @param $short Boolean short circuit on first error
1206          *
1207          * @return Array list of errors
1208          */
1209         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1210                 if ( $action == 'create' ) {
1211                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1212                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1213                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1214                         }
1215                 } elseif ( $action == 'move' ) {
1216                         if ( !$user->isAllowed( 'move-rootuserpages' )
1217                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1218                                 // Show user page-specific message only if the user can move other pages
1219                                 $errors[] = array( 'cant-move-user-page' );
1220                         }
1221
1222                         // Check if user is allowed to move files if it's a file
1223                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1224                                 $errors[] = array( 'movenotallowedfile' );
1225                         }
1226
1227                         if ( !$user->isAllowed( 'move' ) ) {
1228                                 // User can't move anything
1229                                 global $wgGroupPermissions;
1230                                 $userCanMove = false;
1231                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1232                                         $userCanMove = $wgGroupPermissions['user']['move'];
1233                                 }
1234                                 $autoconfirmedCanMove = false;
1235                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1236                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1237                                 }
1238                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1239                                         // custom message if logged-in users without any special rights can move
1240                                         $errors[] = array( 'movenologintext' );
1241                                 } else {
1242                                         $errors[] = array( 'movenotallowed' );
1243                                 }
1244                         }
1245                 } elseif ( $action == 'move-target' ) {
1246                         if ( !$user->isAllowed( 'move' ) ) {
1247                                 // User can't move anything
1248                                 $errors[] = array( 'movenotallowed' );
1249                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1250                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1251                                 // Show user page-specific message only if the user can move other pages
1252                                 $errors[] = array( 'cant-move-to-user-page' );
1253                         }
1254                 } elseif ( !$user->isAllowed( $action ) ) {
1255                         // We avoid expensive display logic for quickUserCan's and such
1256                         $groups = false;
1257                         if ( !$short ) {
1258                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1259                                         User::getGroupsWithPermission( $action ) );
1260                         }
1261
1262                         if ( $groups ) {
1263                                 global $wgLang;
1264                                 $return = array(
1265                                         'badaccess-groups',
1266                                         $wgLang->commaList( $groups ),
1267                                         count( $groups )
1268                                 );
1269                         } else {
1270                                 $return = array( 'badaccess-group0' );
1271                         }
1272                         $errors[] = $return;
1273                 }
1274
1275                 return $errors;
1276         }
1277
1278         /**
1279          * Add the resulting error code to the errors array
1280          *
1281          * @param $errors Array list of current errors
1282          * @param $result Mixed result of errors
1283          *
1284          * @return Array list of errors
1285          */
1286         private function resultToError( $errors, $result ) {
1287                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1288                         // A single array representing an error
1289                         $errors[] = $result;
1290                 } else if ( is_array( $result ) && is_array( $result[0] ) ) {
1291                         // A nested array representing multiple errors
1292                         $errors = array_merge( $errors, $result );
1293                 } else if ( $result !== '' && is_string( $result ) ) {
1294                         // A string representing a message-id
1295                         $errors[] = array( $result );
1296                 } else if ( $result === false ) {
1297                         // a generic "We don't want them to do that"
1298                         $errors[] = array( 'badaccess-group0' );
1299                 }
1300                 return $errors;
1301         }
1302
1303         /**
1304          * Check various permission hooks
1305          *
1306          * @param $action String the action to check
1307          * @param $user User user to check
1308          * @param $errors Array list of current errors
1309          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1310          * @param $short Boolean short circuit on first error
1311          *
1312          * @return Array list of errors
1313          */
1314         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1315                 // Use getUserPermissionsErrors instead
1316                 $result = '';
1317                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1318                         return $result ? array() : array( array( 'badaccess-group0' ) );
1319                 }
1320                 // Check getUserPermissionsErrors hook
1321                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1322                         $errors = $this->resultToError( $errors, $result );
1323                 }
1324                 // Check getUserPermissionsErrorsExpensive hook
1325                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1326                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1327                         $errors = $this->resultToError( $errors, $result );
1328                 }
1329
1330                 return $errors;
1331         }
1332
1333         /**
1334          * Check permissions on special pages & namespaces
1335          *
1336          * @param $action String the action to check
1337          * @param $user User user to check
1338          * @param $errors Array list of current errors
1339          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1340          * @param $short Boolean short circuit on first error
1341          *
1342          * @return Array list of errors
1343          */
1344         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1345                 # Only 'createaccount' and 'execute' can be performed on
1346                 # special pages, which don't actually exist in the DB.
1347                 $specialOKActions = array( 'createaccount', 'execute' );
1348                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1349                         $errors[] = array( 'ns-specialprotected' );
1350                 }
1351
1352                 # Check $wgNamespaceProtection for restricted namespaces
1353                 if ( $this->isNamespaceProtected( $user ) ) {
1354                         $ns = $this->mNamespace == NS_MAIN ?
1355                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1356                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1357                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1358                 }
1359
1360                 return $errors;
1361         }
1362
1363         /**
1364          * Check CSS/JS sub-page permissions
1365          *
1366          * @param $action String the action to check
1367          * @param $user User user to check
1368          * @param $errors Array list of current errors
1369          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1370          * @param $short Boolean short circuit on first error
1371          *
1372          * @return Array list of errors
1373          */
1374         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1375                 # Protect css/js subpages of user pages
1376                 # XXX: this might be better using restrictions
1377                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssSubpage()
1378                 #      and $this->userCanEditJsSubpage() from working
1379                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1380                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1381                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1382                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1383                                 $errors[] = array( 'customcssjsprotected' );
1384                         } else if ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1385                                 $errors[] = array( 'customcssjsprotected' );
1386                         }
1387                 }
1388
1389                 return $errors;
1390         }
1391
1392         /**
1393          * Check against page_restrictions table requirements on this
1394          * page. The user must possess all required rights for this
1395          * action.
1396          *
1397          * @param $action String the action to check
1398          * @param $user User user to check
1399          * @param $errors Array list of current errors
1400          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1401          * @param $short Boolean short circuit on first error
1402          *
1403          * @return Array list of errors
1404          */
1405         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1406                 foreach ( $this->getRestrictions( $action ) as $right ) {
1407                         // Backwards compatibility, rewrite sysop -> protect
1408                         if ( $right == 'sysop' ) {
1409                                 $right = 'protect';
1410                         }
1411                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1412                                 // Users with 'editprotected' permission can edit protected pages
1413                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected' ) ) {
1414                                         // Users with 'editprotected' permission cannot edit protected pages
1415                                         // with cascading option turned on.
1416                                         if ( $this->mCascadeRestriction ) {
1417                                                 $errors[] = array( 'protectedpagetext', $right );
1418                                         }
1419                                 } else {
1420                                         $errors[] = array( 'protectedpagetext', $right );
1421                                 }
1422                         }
1423                 }
1424
1425                 return $errors;
1426         }
1427
1428         /**
1429          * Check restrictions on cascading pages.
1430          *
1431          * @param $action String the action to check
1432          * @param $user User to check
1433          * @param $errors Array list of current errors
1434          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1435          * @param $short Boolean short circuit on first error
1436          *
1437          * @return Array list of errors
1438          */
1439         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1440                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1441                         # We /could/ use the protection level on the source page, but it's
1442                         # fairly ugly as we have to establish a precedence hierarchy for pages
1443                         # included by multiple cascade-protected pages. So just restrict
1444                         # it to people with 'protect' permission, as they could remove the
1445                         # protection anyway.
1446                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1447                         # Cascading protection depends on more than this page...
1448                         # Several cascading protected pages may include this page...
1449                         # Check each cascading level
1450                         # This is only for protection restrictions, not for all actions
1451                         if ( isset( $restrictions[$action] ) ) {
1452                                 foreach ( $restrictions[$action] as $right ) {
1453                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1454                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1455                                                 $pages = '';
1456                                                 foreach ( $cascadingSources as $page )
1457                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1458                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1459                                         }
1460                                 }
1461                         }
1462                 }
1463
1464                 return $errors;
1465         }
1466
1467         /**
1468          * Check action permissions not already checked in checkQuickPermissions
1469          *
1470          * @param $action String the action to check
1471          * @param $user User to check
1472          * @param $errors Array list of current errors
1473          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1474          * @param $short Boolean short circuit on first error
1475          *
1476          * @return Array list of errors
1477          */
1478         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1479                 if ( $action == 'protect' ) {
1480                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1481                                 // If they can't edit, they shouldn't protect.
1482                                 $errors[] = array( 'protect-cantedit' );
1483                         }
1484                 } elseif ( $action == 'create' ) {
1485                         $title_protection = $this->getTitleProtection();
1486                         if( $title_protection ) {
1487                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1488                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1489                                 }
1490                                 if( $title_protection['pt_create_perm'] == '' || !$user->isAllowed( $title_protection['pt_create_perm'] ) ) {
1491                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1492                                 }
1493                         }
1494                 } elseif ( $action == 'move' ) {
1495                         // Check for immobile pages
1496                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1497                                 // Specific message for this case
1498                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1499                         } elseif ( !$this->isMovable() ) {
1500                                 // Less specific message for rarer cases
1501                                 $errors[] = array( 'immobile-page' );
1502                         }
1503                 } elseif ( $action == 'move-target' ) {
1504                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1505                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1506                         } elseif ( !$this->isMovable() ) {
1507                                 $errors[] = array( 'immobile-target-page' );
1508                         }
1509                 }
1510                 return $errors;
1511         }
1512
1513         /**
1514          * Check that the user isn't blocked from editting.
1515          *
1516          * @param $action String the action to check
1517          * @param $user User to check
1518          * @param $errors Array list of current errors
1519          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1520          * @param $short Boolean short circuit on first error
1521          *
1522          * @return Array list of errors
1523          */
1524         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1525                 if( $short && count( $errors ) > 0 ) {
1526                         return $errors;
1527                 }
1528
1529                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1530
1531                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1532                         $errors[] = array( 'confirmedittext' );
1533                 }
1534
1535                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1536                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1537                         $block = $user->mBlock;
1538
1539                         // This is from OutputPage::blockedPage
1540                         // Copied at r23888 by werdna
1541
1542                         $id = $user->blockedBy();
1543                         $reason = $user->blockedFor();
1544                         if ( $reason == '' ) {
1545                                 $reason = wfMsg( 'blockednoreason' );
1546                         }
1547                         $ip = wfGetIP();
1548
1549                         if ( is_numeric( $id ) ) {
1550                                 $name = User::whoIs( $id );
1551                         } else {
1552                                 $name = $id;
1553                         }
1554
1555                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1556                         $blockid = $block->mId;
1557                         $blockExpiry = $user->mBlock->mExpiry;
1558                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1559                         if ( $blockExpiry == 'infinity' ) {
1560                                 // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
1561                                 $scBlockExpiryOptions = wfMsg( 'ipboptions' );
1562
1563                                 foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
1564                                         if ( !strpos( $option, ':' ) )
1565                                                 continue;
1566
1567                                         list( $show, $value ) = explode( ':', $option );
1568
1569                                         if ( $value == 'infinite' || $value == 'indefinite' ) {
1570                                                 $blockExpiry = $show;
1571                                                 break;
1572                                         }
1573                                 }
1574                         } else {
1575                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1576                         }
1577
1578                         $intended = $user->mBlock->mAddress;
1579
1580                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1581                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1582                 }
1583
1584                 return $errors;
1585         }
1586
1587         /**
1588          * Can $user perform $action on this page? This is an internal function,
1589          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1590          * checks on wfReadOnly() and blocks)
1591          *
1592          * @param $action String action that permission needs to be checked for
1593          * @param $user User to check
1594          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1595          * @param $short Bool Set this to true to stop after the first permission error.
1596          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1597          */
1598         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1599                 wfProfileIn( __METHOD__ );
1600
1601                 $errors = array();
1602                 $checks = array(
1603                         'checkQuickPermissions',
1604                         'checkPermissionHooks',
1605                         'checkSpecialsAndNSPermissions',
1606                         'checkCSSandJSPermissions',
1607                         'checkPageRestrictions',
1608                         'checkCascadingSourcesRestrictions',
1609                         'checkActionPermissions',
1610                         'checkUserBlock'
1611                 );
1612
1613                 while( count( $checks ) > 0 &&
1614                            !( $short && count( $errors ) > 0 ) ) {
1615                         $method = array_shift( $checks );
1616                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1617                 }
1618
1619                 wfProfileOut( __METHOD__ );
1620                 return $errors;
1621         }
1622
1623         /**
1624          * Is this title subject to title protection?
1625          * Title protection is the one applied against creation of such title.
1626          *
1627          * @return Mixed An associative array representing any existent title
1628          *   protection, or false if there's none.
1629          */
1630         private function getTitleProtection() {
1631                 // Can't protect pages in special namespaces
1632                 if ( $this->getNamespace() < 0 ) {
1633                         return false;
1634                 }
1635
1636                 // Can't protect pages that exist.
1637                 if ( $this->exists() ) {
1638                         return false;
1639                 }
1640
1641                 if ( !isset( $this->mTitleProtection ) ) {
1642                         $dbr = wfGetDB( DB_SLAVE );
1643                         $res = $dbr->select( 'protected_titles', '*',
1644                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1645                                 __METHOD__ );
1646
1647                         // fetchRow returns false if there are no rows.
1648                         $this->mTitleProtection = $dbr->fetchRow( $res );
1649                 }
1650                 return $this->mTitleProtection;
1651         }
1652
1653         /**
1654          * Update the title protection status
1655          *
1656          * @param $create_perm String Permission required for creation
1657          * @param $reason String Reason for protection
1658          * @param $expiry String Expiry timestamp
1659          * @return boolean true
1660          */
1661         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1662                 global $wgUser, $wgContLang;
1663
1664                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1665                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1666                         // No change
1667                         return true;
1668                 }
1669
1670                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1671
1672                 $dbw = wfGetDB( DB_MASTER );
1673
1674                 $encodedExpiry = Block::encodeExpiry( $expiry, $dbw );
1675
1676                 $expiry_description = '';
1677                 if ( $encodedExpiry != 'infinity' ) {
1678                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1679                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1680                 } else {
1681                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1682                 }
1683
1684                 # Update protection table
1685                 if ( $create_perm != '' ) {
1686                         $this->mTitleProtection = array(
1687                                         'pt_namespace' => $namespace,
1688                                         'pt_title' => $title,
1689                                         'pt_create_perm' => $create_perm,
1690                                         'pt_timestamp' => Block::encodeExpiry( wfTimestampNow(), $dbw ),
1691                                         'pt_expiry' => $encodedExpiry,
1692                                         'pt_user' => $wgUser->getId(),
1693                                         'pt_reason' => $reason,
1694                                 );
1695                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1696                                 $this->mTitleProtection, __METHOD__     );
1697                 } else {
1698                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1699                                 'pt_title' => $title ), __METHOD__ );
1700                         $this->mTitleProtection = false;
1701                 }
1702
1703                 # Update the protection log
1704                 if ( $dbw->affectedRows() ) {
1705                         $log = new LogPage( 'protect' );
1706
1707                         if ( $create_perm ) {
1708                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1709                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1710                         } else {
1711                                 $log->addEntry( 'unprotect', $this, $reason );
1712                         }
1713                 }
1714
1715                 return true;
1716         }
1717
1718         /**
1719          * Remove any title protection due to page existing
1720          */
1721         public function deleteTitleProtection() {
1722                 $dbw = wfGetDB( DB_MASTER );
1723
1724                 $dbw->delete(
1725                         'protected_titles',
1726                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1727                         __METHOD__
1728                 );
1729                 $this->mTitleProtection = false;
1730         }
1731
1732         /**
1733          * Would anybody with sufficient privileges be able to move this page?
1734          * Some pages just aren't movable.
1735          *
1736          * @return Bool TRUE or FALSE
1737          */
1738         public function isMovable() {
1739                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1740         }
1741
1742         /**
1743          * Can $wgUser read this page?
1744          *
1745          * @return Bool
1746          * @todo fold these checks into userCan()
1747          */
1748         public function userCanRead() {
1749                 global $wgUser, $wgGroupPermissions;
1750
1751                 static $useShortcut = null;
1752
1753                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1754                 if ( is_null( $useShortcut ) ) {
1755                         global $wgRevokePermissions;
1756                         $useShortcut = true;
1757                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1758                                 # Not a public wiki, so no shortcut
1759                                 $useShortcut = false;
1760                         } elseif ( !empty( $wgRevokePermissions ) ) {
1761                                 /*
1762                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1763                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1764                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1765                                  * reading is allowed.
1766                                  */
1767                                 foreach ( $wgRevokePermissions as $perms ) {
1768                                         if ( !empty( $perms['read'] ) ) {
1769                                                 # We might be removing the read right from the user, so no shortcut
1770                                                 $useShortcut = false;
1771                                                 break;
1772                                         }
1773                                 }
1774                         }
1775                 }
1776
1777                 $result = null;
1778                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1779                 if ( $result !== null ) {
1780                         return $result;
1781                 }
1782
1783                 # Shortcut for public wikis, allows skipping quite a bit of code
1784                 if ( $useShortcut ) {
1785                         return true;
1786                 }
1787
1788                 if ( $wgUser->isAllowed( 'read' ) ) {
1789                         return true;
1790                 } else {
1791                         global $wgWhitelistRead;
1792
1793                         # Always grant access to the login page.
1794                         # Even anons need to be able to log in.
1795                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1796                                 return true;
1797                         }
1798
1799                         # Bail out if there isn't whitelist
1800                         if ( !is_array( $wgWhitelistRead ) ) {
1801                                 return false;
1802                         }
1803
1804                         # Check for explicit whitelisting
1805                         $name = $this->getPrefixedText();
1806                         $dbName = $this->getPrefixedDBKey();
1807                         // Check with and without underscores
1808                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1809                                 return true;
1810
1811                         # Old settings might have the title prefixed with
1812                         # a colon for main-namespace pages
1813                         if ( $this->getNamespace() == NS_MAIN ) {
1814                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1815                                         return true;
1816                                 }
1817                         }
1818
1819                         # If it's a special page, ditch the subpage bit and check again
1820                         if ( $this->getNamespace() == NS_SPECIAL ) {
1821                                 $name = $this->getDBkey();
1822                                 list( $name, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $name );
1823                                 if ( $name === false ) {
1824                                         # Invalid special page, but we show standard login required message
1825                                         return false;
1826                                 }
1827
1828                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1829                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1830                                         return true;
1831                                 }
1832                         }
1833
1834                 }
1835                 return false;
1836         }
1837
1838         /**
1839          * Is this the mainpage?
1840          * @note Title::newFromText seams to be sufficiently optimized by the title
1841          * cache that we don't need to over-optimize by doing direct comparisons and
1842          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1843          * ends up reporting something differently than $title->isMainPage();
1844          *
1845          * @return Bool
1846          */
1847         public function isMainPage() {
1848                 return $this->equals( Title::newMainPage() );
1849         }
1850
1851         /**
1852          * Is this a talk page of some sort?
1853          *
1854          * @return Bool
1855          */
1856         public function isTalkPage() {
1857                 return MWNamespace::isTalk( $this->getNamespace() );
1858         }
1859
1860         /**
1861          * Is this a subpage?
1862          *
1863          * @return Bool
1864          */
1865         public function isSubpage() {
1866                 return MWNamespace::hasSubpages( $this->mNamespace )
1867                         ? strpos( $this->getText(), '/' ) !== false
1868                         : false;
1869         }
1870
1871         /**
1872          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1873          *
1874          * @return Bool
1875          */
1876         public function hasSubpages() {
1877                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1878                         # Duh
1879                         return false;
1880                 }
1881
1882                 # We dynamically add a member variable for the purpose of this method
1883                 # alone to cache the result.  There's no point in having it hanging
1884                 # around uninitialized in every Title object; therefore we only add it
1885                 # if needed and don't declare it statically.
1886                 if ( isset( $this->mHasSubpages ) ) {
1887                         return $this->mHasSubpages;
1888                 }
1889
1890                 $subpages = $this->getSubpages( 1 );
1891                 if ( $subpages instanceof TitleArray ) {
1892                         return $this->mHasSubpages = (bool)$subpages->count();
1893                 }
1894                 return $this->mHasSubpages = false;
1895         }
1896
1897         /**
1898          * Get all subpages of this page.
1899          *
1900          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
1901          * @return mixed TitleArray, or empty array if this page's namespace
1902          *  doesn't allow subpages
1903          */
1904         public function getSubpages( $limit = -1 ) {
1905                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1906                         return array();
1907                 }
1908
1909                 $dbr = wfGetDB( DB_SLAVE );
1910                 $conds['page_namespace'] = $this->getNamespace();
1911                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1912                 $options = array();
1913                 if ( $limit > -1 ) {
1914                         $options['LIMIT'] = $limit;
1915                 }
1916                 return $this->mSubpages = TitleArray::newFromResult(
1917                         $dbr->select( 'page',
1918                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1919                                 $conds,
1920                                 __METHOD__,
1921                                 $options
1922                         )
1923                 );
1924         }
1925
1926         /**
1927          * Could this page contain custom CSS or JavaScript, based
1928          * on the title?
1929          *
1930          * @return Bool
1931          */
1932         public function isCssOrJsPage() {
1933                 return $this->mNamespace == NS_MEDIAWIKI
1934                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1935         }
1936
1937         /**
1938          * Is this a .css or .js subpage of a user page?
1939          * @return Bool
1940          */
1941         public function isCssJsSubpage() {
1942                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1943         }
1944
1945         /**
1946          * Is this a *valid* .css or .js subpage of a user page?
1947          *
1948          * @return Bool
1949          * @deprecated @since 1.17
1950          */
1951         public function isValidCssJsSubpage() {
1952                 return $this->isCssJsSubpage();
1953         }
1954
1955         /**
1956          * Trim down a .css or .js subpage title to get the corresponding skin name
1957          *
1958          * @return string containing skin name from .css or .js subpage title
1959          */
1960         public function getSkinFromCssJsSubpage() {
1961                 $subpage = explode( '/', $this->mTextform );
1962                 $subpage = $subpage[ count( $subpage ) - 1 ];
1963                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1964         }
1965
1966         /**
1967          * Is this a .css subpage of a user page?
1968          *
1969          * @return Bool
1970          */
1971         public function isCssSubpage() {
1972                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1973         }
1974
1975         /**
1976          * Is this a .js subpage of a user page?
1977          *
1978          * @return Bool
1979          */
1980         public function isJsSubpage() {
1981                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1982         }
1983
1984         /**
1985          * Protect css subpages of user pages: can $wgUser edit
1986          * this page?
1987          *
1988          * @return Bool
1989          * @todo XXX: this might be better using restrictions
1990          */
1991         public function userCanEditCssSubpage() {
1992                 global $wgUser;
1993                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'editusercss' ) )
1994                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1995         }
1996
1997         /**
1998          * Protect js subpages of user pages: can $wgUser edit
1999          * this page?
2000          *
2001          * @return Bool
2002          * @todo XXX: this might be better using restrictions
2003          */
2004         public function userCanEditJsSubpage() {
2005                 global $wgUser;
2006                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'edituserjs' ) )
2007                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2008         }
2009
2010         /**
2011          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2012          *
2013          * @return Bool If the page is subject to cascading restrictions.
2014          */
2015         public function isCascadeProtected() {
2016                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2017                 return ( $sources > 0 );
2018         }
2019
2020         /**
2021          * Cascading protection: Get the source of any cascading restrictions on this page.
2022          *
2023          * @param $getPages Bool Whether or not to retrieve the actual pages
2024          *        that the restrictions have come from.
2025          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2026          *     have come, false for none, or true if such restrictions exist, but $getPages
2027          *     was not set.  The restriction array is an array of each type, each of which
2028          *     contains a array of unique groups.
2029          */
2030         public function getCascadeProtectionSources( $getPages = true ) {
2031                 $pagerestrictions = array();
2032
2033                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2034                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2035                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2036                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2037                 }
2038
2039                 wfProfileIn( __METHOD__ );
2040
2041                 $dbr = wfGetDB( DB_SLAVE );
2042
2043                 if ( $this->getNamespace() == NS_FILE ) {
2044                         $tables = array( 'imagelinks', 'page_restrictions' );
2045                         $where_clauses = array(
2046                                 'il_to' => $this->getDBkey(),
2047                                 'il_from=pr_page',
2048                                 'pr_cascade' => 1
2049                         );
2050                 } else {
2051                         $tables = array( 'templatelinks', 'page_restrictions' );
2052                         $where_clauses = array(
2053                                 'tl_namespace' => $this->getNamespace(),
2054                                 'tl_title' => $this->getDBkey(),
2055                                 'tl_from=pr_page',
2056                                 'pr_cascade' => 1
2057                         );
2058                 }
2059
2060                 if ( $getPages ) {
2061                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2062                                                    'pr_expiry', 'pr_type', 'pr_level' );
2063                         $where_clauses[] = 'page_id=pr_page';
2064                         $tables[] = 'page';
2065                 } else {
2066                         $cols = array( 'pr_expiry' );
2067                 }
2068
2069                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2070
2071                 $sources = $getPages ? array() : false;
2072                 $now = wfTimestampNow();
2073                 $purgeExpired = false;
2074
2075                 foreach ( $res as $row ) {
2076                         $expiry = Block::decodeExpiry( $row->pr_expiry );
2077                         if ( $expiry > $now ) {
2078                                 if ( $getPages ) {
2079                                         $page_id = $row->pr_page;
2080                                         $page_ns = $row->page_namespace;
2081                                         $page_title = $row->page_title;
2082                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2083                                         # Add groups needed for each restriction type if its not already there
2084                                         # Make sure this restriction type still exists
2085
2086                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2087                                                 $pagerestrictions[$row->pr_type] = array();
2088                                         }
2089
2090                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2091                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2092                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2093                                         }
2094                                 } else {
2095                                         $sources = true;
2096                                 }
2097                         } else {
2098                                 // Trigger lazy purge of expired restrictions from the db
2099                                 $purgeExpired = true;
2100                         }
2101                 }
2102                 if ( $purgeExpired ) {
2103                         Title::purgeExpiredRestrictions();
2104                 }
2105
2106                 if ( $getPages ) {
2107                         $this->mCascadeSources = $sources;
2108                         $this->mCascadingRestrictions = $pagerestrictions;
2109                 } else {
2110                         $this->mHasCascadingRestrictions = $sources;
2111                 }
2112
2113                 wfProfileOut( __METHOD__ );
2114                 return array( $sources, $pagerestrictions );
2115         }
2116
2117         /**
2118          * Returns cascading restrictions for the current article
2119          *
2120          * @return Boolean
2121          */
2122         function areRestrictionsCascading() {
2123                 if ( !$this->mRestrictionsLoaded ) {
2124                         $this->loadRestrictions();
2125                 }
2126
2127                 return $this->mCascadeRestriction;
2128         }
2129
2130         /**
2131          * Loads a string into mRestrictions array
2132          *
2133          * @param $res Resource restrictions as an SQL result.
2134          * @param $oldFashionedRestrictions String comma-separated list of page
2135          *        restrictions from page table (pre 1.10)
2136          */
2137         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2138                 $rows = array();
2139
2140                 foreach ( $res as $row ) {
2141                         $rows[] = $row;
2142                 }
2143
2144                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2145         }
2146
2147         /**
2148          * Compiles list of active page restrictions from both page table (pre 1.10)
2149          * and page_restrictions table for this existing page.
2150          * Public for usage by LiquidThreads.
2151          *
2152          * @param $rows array of db result objects
2153          * @param $oldFashionedRestrictions string comma-separated list of page
2154          *        restrictions from page table (pre 1.10)
2155          */
2156         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2157                 $dbr = wfGetDB( DB_SLAVE );
2158
2159                 $restrictionTypes = $this->getRestrictionTypes();
2160
2161                 foreach ( $restrictionTypes as $type ) {
2162                         $this->mRestrictions[$type] = array();
2163                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry( '' );
2164                 }
2165
2166                 $this->mCascadeRestriction = false;
2167
2168                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2169
2170                 if ( $oldFashionedRestrictions === null ) {
2171                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2172                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2173                 }
2174
2175                 if ( $oldFashionedRestrictions != '' ) {
2176
2177                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2178                                 $temp = explode( '=', trim( $restrict ) );
2179                                 if ( count( $temp ) == 1 ) {
2180                                         // old old format should be treated as edit/move restriction
2181                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2182                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2183                                 } else {
2184                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2185                                 }
2186                         }
2187
2188                         $this->mOldRestrictions = true;
2189
2190                 }
2191
2192                 if ( count( $rows ) ) {
2193                         # Current system - load second to make them override.
2194                         $now = wfTimestampNow();
2195                         $purgeExpired = false;
2196
2197                         # Cycle through all the restrictions.
2198                         foreach ( $rows as $row ) {
2199
2200                                 // Don't take care of restrictions types that aren't allowed
2201                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2202                                         continue;
2203
2204                                 // This code should be refactored, now that it's being used more generally,
2205                                 // But I don't really see any harm in leaving it in Block for now -werdna
2206                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
2207
2208                                 // Only apply the restrictions if they haven't expired!
2209                                 if ( !$expiry || $expiry > $now ) {
2210                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2211                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2212
2213                                         $this->mCascadeRestriction |= $row->pr_cascade;
2214                                 } else {
2215                                         // Trigger a lazy purge of expired restrictions
2216                                         $purgeExpired = true;
2217                                 }
2218                         }
2219
2220                         if ( $purgeExpired ) {
2221                                 Title::purgeExpiredRestrictions();
2222                         }
2223                 }
2224
2225                 $this->mRestrictionsLoaded = true;
2226         }
2227
2228         /**
2229          * Load restrictions from the page_restrictions table
2230          *
2231          * @param $oldFashionedRestrictions String comma-separated list of page
2232          *        restrictions from page table (pre 1.10)
2233          */
2234         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2235                 if ( !$this->mRestrictionsLoaded ) {
2236                         if ( $this->exists() ) {
2237                                 $dbr = wfGetDB( DB_SLAVE );
2238
2239                                 $res = $dbr->select( 'page_restrictions', '*',
2240                                         array( 'pr_page' => $this->getArticleId() ), __METHOD__ );
2241
2242                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2243                         } else {
2244                                 $title_protection = $this->getTitleProtection();
2245
2246                                 if ( $title_protection ) {
2247                                         $now = wfTimestampNow();
2248                                         $expiry = Block::decodeExpiry( $title_protection['pt_expiry'] );
2249
2250                                         if ( !$expiry || $expiry > $now ) {
2251                                                 // Apply the restrictions
2252                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2253                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2254                                         } else { // Get rid of the old restrictions
2255                                                 Title::purgeExpiredRestrictions();
2256                                                 $this->mTitleProtection = false;
2257                                         }
2258                                 } else {
2259                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry( '' );
2260                                 }
2261                                 $this->mRestrictionsLoaded = true;
2262                         }
2263                 }
2264         }
2265
2266         /**
2267          * Purge expired restrictions from the page_restrictions table
2268          */
2269         static function purgeExpiredRestrictions() {
2270                 $dbw = wfGetDB( DB_MASTER );
2271                 $dbw->delete(
2272                         'page_restrictions',
2273                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2274                         __METHOD__
2275                 );
2276
2277                 $dbw->delete(
2278                         'protected_titles',
2279                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2280                         __METHOD__
2281                 );
2282         }
2283
2284         /**
2285          * Accessor/initialisation for mRestrictions
2286          *
2287          * @param $action String action that permission needs to be checked for
2288          * @return Array of Strings the array of groups allowed to edit this article
2289          */
2290         public function getRestrictions( $action ) {
2291                 if ( !$this->mRestrictionsLoaded ) {
2292                         $this->loadRestrictions();
2293                 }
2294                 return isset( $this->mRestrictions[$action] )
2295                                 ? $this->mRestrictions[$action]
2296                                 : array();
2297         }
2298
2299         /**
2300          * Get the expiry time for the restriction against a given action
2301          *
2302          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2303          *      or not protected at all, or false if the action is not recognised.
2304          */
2305         public function getRestrictionExpiry( $action ) {
2306                 if ( !$this->mRestrictionsLoaded ) {
2307                         $this->loadRestrictions();
2308                 }
2309                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2310         }
2311
2312         /**
2313          * Is there a version of this page in the deletion archive?
2314          *
2315          * @return Int the number of archived revisions
2316          */
2317         public function isDeleted() {
2318                 if ( $this->getNamespace() < 0 ) {
2319                         $n = 0;
2320                 } else {
2321                         $dbr = wfGetDB( DB_SLAVE );
2322                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2323                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2324                                 __METHOD__
2325                         );
2326                         if ( $this->getNamespace() == NS_FILE ) {
2327                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2328                                         array( 'fa_name' => $this->getDBkey() ),
2329                                         __METHOD__
2330                                 );
2331                         }
2332                 }
2333                 return (int)$n;
2334         }
2335
2336         /**
2337          * Is there a version of this page in the deletion archive?
2338          *
2339          * @return Boolean
2340          */
2341         public function isDeletedQuick() {
2342                 if ( $this->getNamespace() < 0 ) {
2343                         return false;
2344                 }
2345                 $dbr = wfGetDB( DB_SLAVE );
2346                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2347                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2348                         __METHOD__
2349                 );
2350                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2351                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2352                                 array( 'fa_name' => $this->getDBkey() ),
2353                                 __METHOD__
2354                         );
2355                 }
2356                 return $deleted;
2357         }
2358
2359         /**
2360          * Get the article ID for this Title from the link cache,
2361          * adding it if necessary
2362          *
2363          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2364          *  for update
2365          * @return Int the ID
2366          */
2367         public function getArticleID( $flags = 0 ) {
2368                 if ( $this->getNamespace() < 0 ) {
2369                         return $this->mArticleID = 0;
2370                 }
2371                 $linkCache = LinkCache::singleton();
2372                 if ( $flags & self::GAID_FOR_UPDATE ) {
2373                         $oldUpdate = $linkCache->forUpdate( true );
2374                         $linkCache->clearLink( $this );
2375                         $this->mArticleID = $linkCache->addLinkObj( $this );
2376                         $linkCache->forUpdate( $oldUpdate );
2377                 } else {
2378                         if ( -1 == $this->mArticleID ) {
2379                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2380                         }
2381                 }
2382                 return $this->mArticleID;
2383         }
2384
2385         /**
2386          * Is this an article that is a redirect page?
2387          * Uses link cache, adding it if necessary
2388          *
2389          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2390          * @return Bool
2391          */
2392         public function isRedirect( $flags = 0 ) {
2393                 if ( !is_null( $this->mRedirect ) ) {
2394                         return $this->mRedirect;
2395                 }
2396                 # Calling getArticleID() loads the field from cache as needed
2397                 if ( !$this->getArticleID( $flags ) ) {
2398                         return $this->mRedirect = false;
2399                 }
2400                 $linkCache = LinkCache::singleton();
2401                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2402
2403                 return $this->mRedirect;
2404         }
2405
2406         /**
2407          * What is the length of this page?
2408          * Uses link cache, adding it if necessary
2409          *
2410          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2411          * @return Int
2412          */
2413         public function getLength( $flags = 0 ) {
2414                 if ( $this->mLength != -1 ) {
2415                         return $this->mLength;
2416                 }
2417                 # Calling getArticleID() loads the field from cache as needed
2418                 if ( !$this->getArticleID( $flags ) ) {
2419                         return $this->mLength = 0;
2420                 }
2421                 $linkCache = LinkCache::singleton();
2422                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2423
2424                 return $this->mLength;
2425         }
2426
2427         /**
2428          * What is the page_latest field for this page?
2429          *
2430          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2431          * @return Int or 0 if the page doesn't exist
2432          */
2433         public function getLatestRevID( $flags = 0 ) {
2434                 if ( $this->mLatestID !== false ) {
2435                         return intval( $this->mLatestID );
2436                 }
2437                 # Calling getArticleID() loads the field from cache as needed
2438                 if ( !$this->getArticleID( $flags ) ) {
2439                         return $this->mLatestID = 0;
2440                 }
2441                 $linkCache = LinkCache::singleton();
2442                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2443
2444                 return $this->mLatestID;
2445         }
2446
2447         /**
2448          * This clears some fields in this object, and clears any associated
2449          * keys in the "bad links" section of the link cache.
2450          *
2451          * - This is called from Article::doEdit() and Article::insertOn() to allow
2452          * loading of the new page_id. It's also called from
2453          * Article::doDeleteArticle()
2454          *
2455          * @param $newid Int the new Article ID
2456          */
2457         public function resetArticleID( $newid ) {
2458                 $linkCache = LinkCache::singleton();
2459                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2460
2461                 if ( $newid === false ) {
2462                         $this->mArticleID = -1;
2463                 } else {
2464                         $this->mArticleID = intval( $newid );
2465                 }
2466                 $this->mRestrictionsLoaded = false;
2467                 $this->mRestrictions = array();
2468                 $this->mRedirect = null;
2469                 $this->mLength = -1;
2470                 $this->mLatestID = false;
2471         }
2472
2473         /**
2474          * Updates page_touched for this page; called from LinksUpdate.php
2475          *
2476          * @return Bool true if the update succeded
2477          */
2478         public function invalidateCache() {
2479                 if ( wfReadOnly() ) {
2480                         return;
2481                 }
2482                 $dbw = wfGetDB( DB_MASTER );
2483                 $success = $dbw->update(
2484                         'page',
2485                         array( 'page_touched' => $dbw->timestamp() ),
2486                         $this->pageCond(),
2487                         __METHOD__
2488                 );
2489                 HTMLFileCache::clearFileCache( $this );
2490                 return $success;
2491         }
2492
2493         /**
2494          * Prefix some arbitrary text with the namespace or interwiki prefix
2495          * of this object
2496          *
2497          * @param $name String the text
2498          * @return String the prefixed text
2499          * @private
2500          */
2501         /* private */ function prefix( $name ) {
2502                 $p = '';
2503                 if ( $this->mInterwiki != '' ) {
2504                         $p = $this->mInterwiki . ':';
2505                 }
2506
2507                 if ( 0 != $this->mNamespace ) {
2508                         $p .= $this->getNsText() . ':';
2509                 }
2510                 return $p . $name;
2511         }
2512
2513         /**
2514          * Returns a simple regex that will match on characters and sequences invalid in titles.
2515          * Note that this doesn't pick up many things that could be wrong with titles, but that
2516          * replacing this regex with something valid will make many titles valid.
2517          *
2518          * @return String regex string
2519          */
2520         static function getTitleInvalidRegex() {
2521                 static $rxTc = false;
2522                 if ( !$rxTc ) {
2523                         # Matching titles will be held as illegal.
2524                         $rxTc = '/' .
2525                                 # Any character not allowed is forbidden...
2526                                 '[^' . Title::legalChars() . ']' .
2527                                 # URL percent encoding sequences interfere with the ability
2528                                 # to round-trip titles -- you can't link to them consistently.
2529                                 '|%[0-9A-Fa-f]{2}' .
2530                                 # XML/HTML character references produce similar issues.
2531                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2532                                 '|&#[0-9]+;' .
2533                                 '|&#x[0-9A-Fa-f]+;' .
2534                                 '/S';
2535                 }
2536
2537                 return $rxTc;
2538         }
2539
2540         /**
2541          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2542          *
2543          * @param $text String containing title to capitalize
2544          * @param $ns int namespace index, defaults to NS_MAIN
2545          * @return String containing capitalized title
2546          */
2547         public static function capitalize( $text, $ns = NS_MAIN ) {
2548                 global $wgContLang;
2549
2550                 if ( MWNamespace::isCapitalized( $ns ) ) {
2551                         return $wgContLang->ucfirst( $text );
2552                 } else {
2553                         return $text;
2554                 }
2555         }
2556
2557         /**
2558          * Secure and split - main initialisation function for this object
2559          *
2560          * Assumes that mDbkeyform has been set, and is urldecoded
2561          * and uses underscores, but not otherwise munged.  This function
2562          * removes illegal characters, splits off the interwiki and
2563          * namespace prefixes, sets the other forms, and canonicalizes
2564          * everything.
2565          *
2566          * @return Bool true on success
2567          */
2568         private function secureAndSplit() {
2569                 global $wgContLang, $wgLocalInterwiki;
2570
2571                 # Initialisation
2572                 $rxTc = self::getTitleInvalidRegex();
2573
2574                 $this->mInterwiki = $this->mFragment = '';
2575                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2576
2577                 $dbkey = $this->mDbkeyform;
2578
2579                 # Strip Unicode bidi override characters.
2580                 # Sometimes they slip into cut-n-pasted page titles, where the
2581                 # override chars get included in list displays.
2582                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2583
2584                 # Clean up whitespace
2585                 # Note: use of the /u option on preg_replace here will cause
2586                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2587                 # conveniently disabling them.
2588                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2589                 $dbkey = trim( $dbkey, '_' );
2590
2591                 if ( $dbkey == '' ) {
2592                         return false;
2593                 }
2594
2595                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2596                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2597                         return false;
2598                 }
2599
2600                 $this->mDbkeyform = $dbkey;
2601
2602                 # Initial colon indicates main namespace rather than specified default
2603                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2604                 if ( ':' == $dbkey { 0 } ) {
2605                         $this->mNamespace = NS_MAIN;
2606                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2607                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2608                 }
2609
2610                 # Namespace or interwiki prefix
2611                 $firstPass = true;
2612                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2613                 do {
2614                         $m = array();
2615                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2616                                 $p = $m[1];
2617                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2618                                         # Ordinary namespace
2619                                         $dbkey = $m[2];
2620                                         $this->mNamespace = $ns;
2621                                         # For Talk:X pages, check if X has a "namespace" prefix
2622                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2623                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2624                                                         # Disallow Talk:File:x type titles...
2625                                                         return false;
2626                                                 } else if ( Interwiki::isValidInterwiki( $x[1] ) ) {
2627                                                         # Disallow Talk:Interwiki:x type titles...
2628                                                         return false;
2629                                                 }
2630                                         }
2631                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2632                                         if ( !$firstPass ) {
2633                                                 # Can't make a local interwiki link to an interwiki link.
2634                                                 # That's just crazy!
2635                                                 return false;
2636                                         }
2637
2638                                         # Interwiki link
2639                                         $dbkey = $m[2];
2640                                         $this->mInterwiki = $wgContLang->lc( $p );
2641
2642                                         # Redundant interwiki prefix to the local wiki
2643                                         if ( $wgLocalInterwiki !== false
2644                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2645                                         {
2646                                                 if ( $dbkey == '' ) {
2647                                                         # Can't have an empty self-link
2648                                                         return false;
2649                                                 }
2650                                                 $this->mInterwiki = '';
2651                                                 $firstPass = false;
2652                                                 # Do another namespace split...
2653                                                 continue;
2654                                         }
2655
2656                                         # If there's an initial colon after the interwiki, that also
2657                                         # resets the default namespace
2658                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2659                                                 $this->mNamespace = NS_MAIN;
2660                                                 $dbkey = substr( $dbkey, 1 );
2661                                         }
2662                                 }
2663                                 # If there's no recognized interwiki or namespace,
2664                                 # then let the colon expression be part of the title.
2665                         }
2666                         break;
2667                 } while ( true );
2668
2669                 # We already know that some pages won't be in the database!
2670                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2671                         $this->mArticleID = 0;
2672                 }
2673                 $fragment = strstr( $dbkey, '#' );
2674                 if ( false !== $fragment ) {
2675                         $this->setFragment( preg_replace( '/^#_*/', '#', $fragment ) );
2676                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2677                         # remove whitespace again: prevents "Foo_bar_#"
2678                         # becoming "Foo_bar_"
2679                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2680                 }
2681
2682                 # Reject illegal characters.
2683                 if ( preg_match( $rxTc, $dbkey ) ) {
2684                         return false;
2685                 }
2686
2687                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2688                 # reachable due to the way web browsers deal with 'relative' URLs.
2689                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2690                 if ( strpos( $dbkey, '.' ) !== false &&
2691                          ( $dbkey === '.' || $dbkey === '..' ||
2692                            strpos( $dbkey, './' ) === 0  ||
2693                            strpos( $dbkey, '../' ) === 0 ||
2694                            strpos( $dbkey, '/./' ) !== false ||
2695                            strpos( $dbkey, '/../' ) !== false  ||
2696                            substr( $dbkey, -2 ) == '/.' ||
2697                            substr( $dbkey, -3 ) == '/..' ) )
2698                 {
2699                         return false;
2700                 }
2701
2702                 # Magic tilde sequences? Nu-uh!
2703                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2704                         return false;
2705                 }
2706
2707                 # Limit the size of titles to 255 bytes. This is typically the size of the
2708                 # underlying database field. We make an exception for special pages, which
2709                 # don't need to be stored in the database, and may edge over 255 bytes due
2710                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2711                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2712                   strlen( $dbkey ) > 512 )
2713                 {
2714                         return false;
2715                 }
2716
2717                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2718                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2719                 # other site might be case-sensitive.
2720                 $this->mUserCaseDBKey = $dbkey;
2721                 if ( $this->mInterwiki == '' ) {
2722                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2723                 }
2724
2725                 # Can't make a link to a namespace alone... "empty" local links can only be
2726                 # self-links with a fragment identifier.
2727                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2728                         return false;
2729                 }
2730
2731                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2732                 // IP names are not allowed for accounts, and can only be referring to
2733                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2734                 // there are numerous ways to present the same IP. Having sp:contribs scan
2735                 // them all is silly and having some show the edits and others not is
2736                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2737                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2738                         ? IP::sanitizeIP( $dbkey )
2739                         : $dbkey;
2740
2741                 // Any remaining initial :s are illegal.
2742                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2743                         return false;
2744                 }
2745
2746                 # Fill fields
2747                 $this->mDbkeyform = $dbkey;
2748                 $this->mUrlform = wfUrlencode( $dbkey );
2749
2750                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2751
2752                 return true;
2753         }
2754
2755         /**
2756          * Set the fragment for this title. Removes the first character from the
2757          * specified fragment before setting, so it assumes you're passing it with
2758          * an initial "#".
2759          *
2760          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2761          * Still in active use privately.
2762          *
2763          * @param $fragment String text
2764          */
2765         public function setFragment( $fragment ) {
2766                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2767         }
2768
2769         /**
2770          * Get a Title object associated with the talk page of this article
2771          *
2772          * @return Title the object for the talk page
2773          */
2774         public function getTalkPage() {
2775                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2776         }
2777
2778         /**
2779          * Get a title object associated with the subject page of this
2780          * talk page
2781          *
2782          * @return Title the object for the subject page
2783          */
2784         public function getSubjectPage() {
2785                 // Is this the same title?
2786                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2787                 if ( $this->getNamespace() == $subjectNS ) {
2788                         return $this;
2789                 }
2790                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2791         }
2792
2793         /**
2794          * Get an array of Title objects linking to this Title
2795          * Also stores the IDs in the link cache.
2796          *
2797          * WARNING: do not use this function on arbitrary user-supplied titles!
2798          * On heavily-used templates it will max out the memory.
2799          *
2800          * @param $options Array: may be FOR UPDATE
2801          * @param $table String: table name
2802          * @param $prefix String: fields prefix
2803          * @return Array of Title objects linking here
2804          */
2805         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2806                 $linkCache = LinkCache::singleton();
2807
2808                 if ( count( $options ) > 0 ) {
2809                         $db = wfGetDB( DB_MASTER );
2810                 } else {
2811                         $db = wfGetDB( DB_SLAVE );
2812                 }
2813
2814                 $res = $db->select(
2815                         array( 'page', $table ),
2816                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2817                         array(
2818                                 "{$prefix}_from=page_id",
2819                                 "{$prefix}_namespace" => $this->getNamespace(),
2820                                 "{$prefix}_title"     => $this->getDBkey() ),
2821                         __METHOD__,
2822                         $options
2823                 );
2824
2825                 $retVal = array();
2826                 if ( $db->numRows( $res ) ) {
2827                         foreach ( $res as $row ) {
2828                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2829                                 if ( $titleObj ) {
2830                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2831                                         $retVal[] = $titleObj;
2832                                 }
2833                         }
2834                 }
2835                 return $retVal;
2836         }
2837
2838         /**
2839          * Get an array of Title objects using this Title as a template
2840          * Also stores the IDs in the link cache.
2841          *
2842          * WARNING: do not use this function on arbitrary user-supplied titles!
2843          * On heavily-used templates it will max out the memory.
2844          *
2845          * @param $options Array: may be FOR UPDATE
2846          * @return Array of Title the Title objects linking here
2847          */
2848         public function getTemplateLinksTo( $options = array() ) {
2849                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2850         }
2851
2852         /**
2853          * Get an array of Title objects referring to non-existent articles linked from this page
2854          *
2855          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2856          * @return Array of Title the Title objects
2857          */
2858         public function getBrokenLinksFrom() {
2859                 if ( $this->getArticleId() == 0 ) {
2860                         # All links from article ID 0 are false positives
2861                         return array();
2862                 }
2863
2864                 $dbr = wfGetDB( DB_SLAVE );
2865                 $res = $dbr->select(
2866                         array( 'page', 'pagelinks' ),
2867                         array( 'pl_namespace', 'pl_title' ),
2868                         array(
2869                                 'pl_from' => $this->getArticleId(),
2870                                 'page_namespace IS NULL'
2871                         ),
2872                         __METHOD__, array(),
2873                         array(
2874                                 'page' => array(
2875                                         'LEFT JOIN',
2876                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2877                                 )
2878                         )
2879                 );
2880
2881                 $retVal = array();
2882                 foreach ( $res as $row ) {
2883                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2884                 }
2885                 return $retVal;
2886         }
2887
2888
2889         /**
2890          * Get a list of URLs to purge from the Squid cache when this
2891          * page changes
2892          *
2893          * @return Array of String the URLs
2894          */
2895         public function getSquidURLs() {
2896                 global $wgContLang;
2897
2898                 $urls = array(
2899                         $this->getInternalURL(),
2900                         $this->getInternalURL( 'action=history' )
2901                 );
2902
2903                 // purge variant urls as well
2904                 if ( $wgContLang->hasVariants() ) {
2905                         $variants = $wgContLang->getVariants();
2906                         foreach ( $variants as $vCode ) {
2907                                 $urls[] = $this->getInternalURL( '', $vCode );
2908                         }
2909                 }
2910
2911                 return $urls;
2912         }
2913
2914         /**
2915          * Purge all applicable Squid URLs
2916          */
2917         public function purgeSquid() {
2918                 global $wgUseSquid;
2919                 if ( $wgUseSquid ) {
2920                         $urls = $this->getSquidURLs();
2921                         $u = new SquidUpdate( $urls );
2922                         $u->doUpdate();
2923                 }
2924         }
2925
2926         /**
2927          * Move this page without authentication
2928          *
2929          * @param $nt Title the new page Title
2930          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
2931          */
2932         public function moveNoAuth( &$nt ) {
2933                 return $this->moveTo( $nt, false );
2934         }
2935
2936         /**
2937          * Check whether a given move operation would be valid.
2938          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2939          *
2940          * @param $nt Title the new title
2941          * @param $auth Bool indicates whether $wgUser's permissions
2942          *  should be checked
2943          * @param $reason String is the log summary of the move, used for spam checking
2944          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
2945          */
2946         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2947                 global $wgUser;
2948
2949                 $errors = array();
2950                 if ( !$nt ) {
2951                         // Normally we'd add this to $errors, but we'll get
2952                         // lots of syntax errors if $nt is not an object
2953                         return array( array( 'badtitletext' ) );
2954                 }
2955                 if ( $this->equals( $nt ) ) {
2956                         $errors[] = array( 'selfmove' );
2957                 }
2958                 if ( !$this->isMovable() ) {
2959                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2960                 }
2961                 if ( $nt->getInterwiki() != '' ) {
2962                         $errors[] = array( 'immobile-target-namespace-iw' );
2963                 }
2964                 if ( !$nt->isMovable() ) {
2965                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
2966                 }
2967
2968                 $oldid = $this->getArticleID();
2969                 $newid = $nt->getArticleID();
2970
2971                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2972                         $errors[] = array( 'articleexists' );
2973                 }
2974                 if ( ( $this->getDBkey() == '' ) ||
2975                          ( !$oldid ) ||
2976                          ( $nt->getDBkey() == '' ) ) {
2977                         $errors[] = array( 'badarticleerror' );
2978                 }
2979
2980                 // Image-specific checks
2981                 if ( $this->getNamespace() == NS_FILE ) {
2982                         if ( $nt->getNamespace() != NS_FILE ) {
2983                                 $errors[] = array( 'imagenocrossnamespace' );
2984                         }
2985                         $file = wfLocalFile( $this );
2986                         if ( $file->exists() ) {
2987                                 if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
2988                                         $errors[] = array( 'imageinvalidfilename' );
2989                                 }
2990                                 if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
2991                                         $errors[] = array( 'imagetypemismatch' );
2992                                 }
2993                         }
2994                         $destfile = wfLocalFile( $nt );
2995                         if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destfile->exists() && wfFindFile( $nt ) ) {
2996                                 $errors[] = array( 'file-exists-sharedrepo' );
2997                         }
2998                 }
2999
3000                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3001                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3002                 }
3003
3004                 if ( $auth ) {
3005                         $errors = wfMergeErrorArrays( $errors,
3006                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3007                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3008                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3009                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3010                 }
3011
3012                 $match = EditPage::matchSummarySpamRegex( $reason );
3013                 if ( $match !== false ) {
3014                         // This is kind of lame, won't display nice
3015                         $errors[] = array( 'spamprotectiontext' );
3016                 }
3017
3018                 $err = null;
3019                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3020                         $errors[] = array( 'hookaborted', $err );
3021                 }
3022
3023                 # The move is allowed only if (1) the target doesn't exist, or
3024                 # (2) the target is a redirect to the source, and has no history
3025                 # (so we can undo bad moves right after they're done).
3026
3027                 if ( 0 != $newid ) { # Target exists; check for validity
3028                         if ( !$this->isValidMoveTarget( $nt ) ) {
3029                                 $errors[] = array( 'articleexists' );
3030                         }
3031                 } else {
3032                         $tp = $nt->getTitleProtection();
3033                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3034                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3035                                 $errors[] = array( 'cantmove-titleprotected' );
3036                         }
3037                 }
3038                 if ( empty( $errors ) ) {
3039                         return true;
3040                 }
3041                 return $errors;
3042         }
3043
3044         /**
3045          * Move a title to a new location
3046          *
3047          * @param $nt Title the new title
3048          * @param $auth Bool indicates whether $wgUser's permissions
3049          *  should be checked
3050          * @param $reason String the reason for the move
3051          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3052          *  Ignored if the user doesn't have the suppressredirect right.
3053          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3054          */
3055         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3056                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3057                 if ( is_array( $err ) ) {
3058                         return $err;
3059                 }
3060
3061                 // If it is a file, move it first. It is done before all other moving stuff is
3062                 // done because it's hard to revert
3063                 $dbw = wfGetDB( DB_MASTER );
3064                 if ( $this->getNamespace() == NS_FILE ) {
3065                         $file = wfLocalFile( $this );
3066                         if ( $file->exists() ) {
3067                                 $status = $file->move( $nt );
3068                                 if ( !$status->isOk() ) {
3069                                         return $status->getErrorsArray();
3070                                 }
3071                         }
3072                 }
3073
3074                 $pageid = $this->getArticleID();
3075                 $protected = $this->isProtected();
3076                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3077
3078                 // Do the actual move
3079                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3080                 if ( is_array( $err ) ) {
3081                         return $err;
3082                 }
3083
3084                 $redirid = $this->getArticleID();
3085
3086                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3087                 // cl_timestamp, which may disturb time-based lists on some sites.
3088                 $prefix = $dbw->selectField(
3089                         'categorylinks',
3090                         'cl_sortkey_prefix',
3091                         array( 'cl_from' => $pageid ),
3092                         __METHOD__
3093                 );
3094                 $dbw->update( 'categorylinks',
3095                         array(
3096                                 'cl_sortkey' => Collation::singleton()->getSortKey(
3097                                         $nt->getCategorySortkey( $prefix ) ),
3098                                 'cl_timestamp=cl_timestamp' ),
3099                         array( 'cl_from' => $pageid ),
3100                         __METHOD__ );
3101
3102                 if ( $protected ) {
3103                         # Protect the redirect title as the title used to be...
3104                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3105                                 array(
3106                                         'pr_page'    => $redirid,
3107                                         'pr_type'    => 'pr_type',
3108                                         'pr_level'   => 'pr_level',
3109                                         'pr_cascade' => 'pr_cascade',
3110                                         'pr_user'    => 'pr_user',
3111                                         'pr_expiry'  => 'pr_expiry'
3112                                 ),
3113                                 array( 'pr_page' => $pageid ),
3114                                 __METHOD__,
3115                                 array( 'IGNORE' )
3116                         );
3117                         # Update the protection log
3118                         $log = new LogPage( 'protect' );
3119                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3120                         if ( $reason ) {
3121                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3122                         }
3123                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) ); // FIXME: $params?
3124                 }
3125
3126                 # Update watchlists
3127                 $oldnamespace = $this->getNamespace() & ~1;
3128                 $newnamespace = $nt->getNamespace() & ~1;
3129                 $oldtitle = $this->getDBkey();
3130                 $newtitle = $nt->getDBkey();
3131
3132                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3133                         WatchedItem::duplicateEntries( $this, $nt );
3134                 }
3135
3136                 # Update search engine
3137                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3138                 $u->doUpdate();
3139                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3140                 $u->doUpdate();
3141
3142                 # Update site_stats
3143                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3144                         # No longer a content page
3145                         # Not viewed, edited, removing
3146                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3147                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3148                         # Now a content page
3149                         # Not viewed, edited, adding
3150                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3151                 } elseif ( $pageCountChange ) {
3152                         # Redirect added
3153                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3154                 } else {
3155                         # Nothing special
3156                         $u = false;
3157                 }
3158                 if ( $u ) {
3159                         $u->doUpdate();
3160                 }
3161                 # Update message cache for interface messages
3162                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3163                         # @bug 17860: old article can be deleted, if this the case,
3164                         # delete it from message cache
3165                         if ( $this->getArticleID() === 0 ) {
3166                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3167                         } else {
3168                                 $oldarticle = new Article( $this );
3169                                 MessageCache::singleton()->replace( $this->getDBkey(), $oldarticle->getContent() );
3170                         }
3171                 }
3172                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3173                         $newarticle = new Article( $nt );
3174                         MessageCache::singleton()->replace( $nt->getDBkey(), $newarticle->getContent() );
3175                 }
3176
3177                 global $wgUser;
3178                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3179                 return true;
3180         }
3181
3182         /**
3183          * Move page to a title which is either a redirect to the
3184          * source page or nonexistent
3185          *
3186          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3187          * @param $reason String The reason for the move
3188          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3189          *   if the user doesn't have the suppressredirect right
3190          */
3191         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3192                 global $wgUser, $wgContLang;
3193
3194                 $moveOverRedirect = $nt->exists();
3195
3196                 $commentMsg = ( $moveOverRedirect ? '1movedto2_redir' : '1movedto2' );
3197                 $comment = wfMsgForContent( $commentMsg, $this->getPrefixedText(), $nt->getPrefixedText() );
3198
3199                 if ( $reason ) {
3200                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3201                 }
3202                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3203                 $comment = $wgContLang->truncate( $comment, 250 );
3204
3205                 $oldid = $this->getArticleID();
3206                 $latest = $this->getLatestRevID();
3207
3208                 $dbw = wfGetDB( DB_MASTER );
3209
3210                 if ( $moveOverRedirect ) {
3211                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3212
3213                         $newid = $nt->getArticleID();
3214                         $newns = $nt->getNamespace();
3215                         $newdbk = $nt->getDBkey();
3216
3217                         # Delete the old redirect. We don't save it to history since
3218                         # by definition if we've got here it's rather uninteresting.
3219                         # We have to remove it so that the next step doesn't trigger
3220                         # a conflict on the unique namespace+title index...
3221                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3222                         if ( !$dbw->cascadingDeletes() ) {
3223                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3224                                 global $wgUseTrackbacks;
3225                                 if ( $wgUseTrackbacks ) {
3226                                         $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3227                                 }
3228                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3229                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3230                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3231                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3232                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3233                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3234                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3235                         }
3236                         // If the target page was recently created, it may have an entry in recentchanges still
3237                         $dbw->delete( 'recentchanges',
3238                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3239                                 __METHOD__
3240                         );
3241                 }
3242
3243                 # Save a null revision in the page's history notifying of the move
3244                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3245                 if ( !is_object( $nullRevision ) ) {
3246                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3247                 }
3248                 $nullRevId = $nullRevision->insertOn( $dbw );
3249
3250                 $article = new Article( $this );
3251                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3252
3253                 # Change the name of the target page:
3254                 $dbw->update( 'page',
3255                         /* SET */ array(
3256                                 'page_touched'   => $dbw->timestamp(),
3257                                 'page_namespace' => $nt->getNamespace(),
3258                                 'page_title'     => $nt->getDBkey(),
3259                                 'page_latest'    => $nullRevId,
3260                         ),
3261                         /* WHERE */ array( 'page_id' => $oldid ),
3262                         __METHOD__
3263                 );
3264                 $nt->resetArticleID( $oldid );
3265
3266                 # Recreate the redirect, this time in the other direction.
3267                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3268                         $mwRedir = MagicWord::get( 'redirect' );
3269                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3270                         $redirectArticle = new Article( $this );
3271                         $newid = $redirectArticle->insertOn( $dbw );
3272                         $redirectRevision = new Revision( array(
3273                                 'page'    => $newid,
3274                                 'comment' => $comment,
3275                                 'text'    => $redirectText ) );
3276                         $redirectRevision->insertOn( $dbw );
3277                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3278
3279                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3280
3281                         # Now, we record the link from the redirect to the new title.
3282                         # It should have no other outgoing links...
3283                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3284                         $dbw->insert( 'pagelinks',
3285                                 array(
3286                                         'pl_from'      => $newid,
3287                                         'pl_namespace' => $nt->getNamespace(),
3288                                         'pl_title'     => $nt->getDBkey() ),
3289                                 __METHOD__ );
3290                         $redirectSuppressed = false;
3291                 } else {
3292                         $this->resetArticleID( 0 );
3293                         $redirectSuppressed = true;
3294                 }
3295
3296                 # Log the move
3297                 $log = new LogPage( 'move' );
3298                 $logType = ( $moveOverRedirect ? 'move_redir' : 'move' );
3299                 $log->addEntry( $logType, $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3300
3301                 # Purge caches for old and new titles
3302                 if ( $moveOverRedirect ) {
3303                         # A simple purge is enough when moving over a redirect
3304                         $nt->purgeSquid();
3305                 } else {
3306                         # Purge caches as per article creation, including any pages that link to this title
3307                         Article::onArticleCreate( $nt );
3308                 }
3309                 $this->purgeSquid();
3310         }
3311
3312         /**
3313          * Move this page's subpages to be subpages of $nt
3314          *
3315          * @param $nt Title Move target
3316          * @param $auth bool Whether $wgUser's permissions should be checked
3317          * @param $reason string The reason for the move
3318          * @param $createRedirect bool Whether to create redirects from the old subpages to
3319          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3320          * @return mixed array with old page titles as keys, and strings (new page titles) or
3321          *     arrays (errors) as values, or an error array with numeric indices if no pages
3322          *     were moved
3323          */
3324         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3325                 global $wgMaximumMovedPages;
3326                 // Check permissions
3327                 if ( !$this->userCan( 'move-subpages' ) ) {
3328                         return array( 'cant-move-subpages' );
3329                 }
3330                 // Do the source and target namespaces support subpages?
3331                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3332                         return array( 'namespace-nosubpages',
3333                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3334                 }
3335                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3336                         return array( 'namespace-nosubpages',
3337                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3338                 }
3339
3340                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3341                 $retval = array();
3342                 $count = 0;
3343                 foreach ( $subpages as $oldSubpage ) {
3344                         $count++;
3345                         if ( $count > $wgMaximumMovedPages ) {
3346                                 $retval[$oldSubpage->getPrefixedTitle()] =
3347                                                 array( 'movepage-max-pages',
3348                                                         $wgMaximumMovedPages );
3349                                 break;
3350                         }
3351
3352                         // We don't know whether this function was called before
3353                         // or after moving the root page, so check both
3354                         // $this and $nt
3355                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3356                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3357                         {
3358                                 // When moving a page to a subpage of itself,
3359                                 // don't move it twice
3360                                 continue;
3361                         }
3362                         $newPageName = preg_replace(
3363                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3364                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3365                                         $oldSubpage->getDBkey() );
3366                         if ( $oldSubpage->isTalkPage() ) {
3367                                 $newNs = $nt->getTalkPage()->getNamespace();
3368                         } else {
3369                                 $newNs = $nt->getSubjectPage()->getNamespace();
3370                         }
3371                         # Bug 14385: we need makeTitleSafe because the new page names may
3372                         # be longer than 255 characters.
3373                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3374
3375                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3376                         if ( $success === true ) {
3377                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3378                         } else {
3379                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3380                         }
3381                 }
3382                 return $retval;
3383         }
3384
3385         /**
3386          * Checks if this page is just a one-rev redirect.
3387          * Adds lock, so don't use just for light purposes.
3388          *
3389          * @return Bool
3390          */
3391         public function isSingleRevRedirect() {
3392                 $dbw = wfGetDB( DB_MASTER );
3393                 # Is it a redirect?
3394                 $row = $dbw->selectRow( 'page',
3395                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3396                         $this->pageCond(),
3397                         __METHOD__,
3398                         array( 'FOR UPDATE' )
3399                 );
3400                 # Cache some fields we may want
3401                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3402                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3403                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3404                 if ( !$this->mRedirect ) {
3405                         return false;
3406                 }
3407                 # Does the article have a history?
3408                 $row = $dbw->selectField( array( 'page', 'revision' ),
3409                         'rev_id',
3410                         array( 'page_namespace' => $this->getNamespace(),
3411                                 'page_title' => $this->getDBkey(),
3412                                 'page_id=rev_page',
3413                                 'page_latest != rev_id'
3414                         ),
3415                         __METHOD__,
3416                         array( 'FOR UPDATE' )
3417                 );
3418                 # Return true if there was no history
3419                 return ( $row === false );
3420         }
3421
3422         /**
3423          * Checks if $this can be moved to a given Title
3424          * - Selects for update, so don't call it unless you mean business
3425          *
3426          * @param $nt Title the new title to check
3427          * @return Bool
3428          */
3429         public function isValidMoveTarget( $nt ) {
3430                 # Is it an existing file?
3431                 if ( $nt->getNamespace() == NS_FILE ) {
3432                         $file = wfLocalFile( $nt );
3433                         if ( $file->exists() ) {
3434                                 wfDebug( __METHOD__ . ": file exists\n" );
3435                                 return false;
3436                         }
3437                 }
3438                 # Is it a redirect with no history?
3439                 if ( !$nt->isSingleRevRedirect() ) {
3440                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3441                         return false;
3442                 }
3443                 # Get the article text
3444                 $rev = Revision::newFromTitle( $nt );
3445                 $text = $rev->getText();
3446                 # Does the redirect point to the source?
3447                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3448                 $m = array();
3449                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3450                         $redirTitle = Title::newFromText( $m[1] );
3451                         if ( !is_object( $redirTitle ) ||
3452                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3453                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3454                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3455                                 return false;
3456                         }
3457                 } else {
3458                         # Fail safe
3459                         wfDebug( __METHOD__ . ": failsafe\n" );
3460                         return false;
3461                 }
3462                 return true;
3463         }
3464
3465         /**
3466          * Can this title be added to a user's watchlist?
3467          *
3468          * @return Bool TRUE or FALSE
3469          */
3470         public function isWatchable() {
3471                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3472         }
3473
3474         /**
3475          * Get categories to which this Title belongs and return an array of
3476          * categories' names.
3477          *
3478          * @return Array of parents in the form:
3479          *        $parent => $currentarticle
3480          */
3481         public function getParentCategories() {
3482                 global $wgContLang;
3483
3484                 $data = array();
3485
3486                 $titleKey = $this->getArticleId();
3487
3488                 if ( $titleKey === 0 ) {
3489                         return $data;
3490                 }
3491
3492                 $dbr = wfGetDB( DB_SLAVE );
3493
3494                 $res = $dbr->select( 'categorylinks', '*',
3495                         array(
3496                                 'cl_from' => $titleKey,
3497                         ),
3498                         __METHOD__,
3499                         array()
3500                 );
3501
3502                 if ( $dbr->numRows( $res ) > 0 ) {
3503                         foreach ( $res as $row ) {
3504                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3505                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3506                         }
3507                 }
3508                 return $data;
3509         }
3510
3511         /**
3512          * Get a tree of parent categories
3513          *
3514          * @param $children Array with the children in the keys, to check for circular refs
3515          * @return Array Tree of parent categories
3516          */
3517         public function getParentCategoryTree( $children = array() ) {
3518                 $stack = array();
3519                 $parents = $this->getParentCategories();
3520
3521                 if ( $parents ) {
3522                         foreach ( $parents as $parent => $current ) {
3523                                 if ( array_key_exists( $parent, $children ) ) {
3524                                         # Circular reference
3525                                         $stack[$parent] = array();
3526                                 } else {
3527                                         $nt = Title::newFromText( $parent );
3528                                         if ( $nt ) {
3529                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3530                                         }
3531                                 }
3532                         }
3533                 }
3534
3535                 return $stack;
3536         }
3537
3538         /**
3539          * Get an associative array for selecting this title from
3540          * the "page" table
3541          *
3542          * @return Array suitable for the $where parameter of DB::select()
3543          */
3544         public function pageCond() {
3545                 if ( $this->mArticleID > 0 ) {
3546                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3547                         return array( 'page_id' => $this->mArticleID );
3548                 } else {
3549                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3550                 }
3551         }
3552
3553         /**
3554          * Get the revision ID of the previous revision
3555          *
3556          * @param $revId Int Revision ID. Get the revision that was before this one.
3557          * @param $flags Int Title::GAID_FOR_UPDATE
3558          * @return Int|Bool Old revision ID, or FALSE if none exists
3559          */
3560         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3561                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3562                 return $db->selectField( 'revision', 'rev_id',
3563                         array(
3564                                 'rev_page' => $this->getArticleId( $flags ),
3565                                 'rev_id < ' . intval( $revId )
3566                         ),
3567                         __METHOD__,
3568                         array( 'ORDER BY' => 'rev_id DESC' )
3569                 );
3570         }
3571
3572         /**
3573          * Get the revision ID of the next revision
3574          *
3575          * @param $revId Int Revision ID. Get the revision that was after this one.
3576          * @param $flags Int Title::GAID_FOR_UPDATE
3577          * @return Int|Bool Next revision ID, or FALSE if none exists
3578          */
3579         public function getNextRevisionID( $revId, $flags = 0 ) {
3580                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3581                 return $db->selectField( 'revision', 'rev_id',
3582                         array(
3583                                 'rev_page' => $this->getArticleId( $flags ),
3584                                 'rev_id > ' . intval( $revId )
3585                         ),
3586                         __METHOD__,
3587                         array( 'ORDER BY' => 'rev_id' )
3588                 );
3589         }
3590
3591         /**
3592          * Get the first revision of the page
3593          *
3594          * @param $flags Int Title::GAID_FOR_UPDATE
3595          * @return Revision|Null if page doesn't exist
3596          */
3597         public function getFirstRevision( $flags = 0 ) {
3598                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3599                 $pageId = $this->getArticleId( $flags );
3600                 if ( !$pageId ) {
3601                         return null;
3602                 }
3603                 $row = $db->selectRow( 'revision', '*',
3604                         array( 'rev_page' => $pageId ),
3605                         __METHOD__,
3606                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3607                 );
3608                 if ( !$row ) {
3609                         return null;
3610                 } else {
3611                         return new Revision( $row );
3612                 }
3613         }
3614
3615         /**
3616          * Check if this is a new page
3617          *
3618          * @return bool
3619          */
3620         public function isNewPage() {
3621                 $dbr = wfGetDB( DB_SLAVE );
3622                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3623         }
3624
3625         /**
3626          * Get the oldest revision timestamp of this page
3627          *
3628          * @return String: MW timestamp
3629          */
3630         public function getEarliestRevTime() {
3631                 $dbr = wfGetDB( DB_SLAVE );
3632                 if ( $this->exists() ) {
3633                         $min = $dbr->selectField( 'revision',
3634                                 'MIN(rev_timestamp)',
3635                                 array( 'rev_page' => $this->getArticleId() ),
3636                                 __METHOD__ );
3637                         return wfTimestampOrNull( TS_MW, $min );
3638                 }
3639                 return null;
3640         }
3641
3642         /**
3643          * Get the number of revisions between the given revision IDs.
3644          * Used for diffs and other things that really need it.
3645          *
3646          * @param $old Int Revision ID.
3647          * @param $new Int Revision ID.
3648          * @return Int Number of revisions between these IDs.
3649          */
3650         public function countRevisionsBetween( $old, $new ) {
3651                 $dbr = wfGetDB( DB_SLAVE );
3652                 return (int)$dbr->selectField( 'revision', 'count(*)', array(
3653                                 'rev_page' => intval( $this->getArticleId() ),
3654                                 'rev_id > ' . intval( $old ),
3655                                 'rev_id < ' . intval( $new )
3656                         ), __METHOD__
3657                 );
3658         }
3659
3660         /**
3661          * Get the number of authors between the given revision IDs.
3662          * Used for diffs and other things that really need it.
3663          *
3664          * @param $fromRevId Int Revision ID (first before range)
3665          * @param $toRevId Int Revision ID (first after range)
3666          * @param $limit Int Maximum number of authors
3667          * @param $flags Int Title::GAID_FOR_UPDATE
3668          * @return Int
3669          */
3670         public function countAuthorsBetween( $fromRevId, $toRevId, $limit, $flags = 0 ) {
3671                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3672                 $res = $db->select( 'revision', 'DISTINCT rev_user_text',
3673                         array(
3674                                 'rev_page' => $this->getArticleID(),
3675                                 'rev_id > ' . (int)$fromRevId,
3676                                 'rev_id < ' . (int)$toRevId
3677                         ), __METHOD__,
3678                         array( 'LIMIT' => $limit )
3679                 );
3680                 return (int)$db->numRows( $res );
3681         }
3682
3683         /**
3684          * Compare with another title.
3685          *
3686          * @param $title Title
3687          * @return Bool
3688          */
3689         public function equals( Title $title ) {
3690                 // Note: === is necessary for proper matching of number-like titles.
3691                 return $this->getInterwiki() === $title->getInterwiki()
3692                         && $this->getNamespace() == $title->getNamespace()
3693                         && $this->getDBkey() === $title->getDBkey();
3694         }
3695
3696         /**
3697          * Callback for usort() to do title sorts by (namespace, title)
3698          *
3699          * @return Integer: result of string comparison, or namespace comparison
3700          */
3701         public static function compare( $a, $b ) {
3702                 if ( $a->getNamespace() == $b->getNamespace() ) {
3703                         return strcmp( $a->getText(), $b->getText() );
3704                 } else {
3705                         return $a->getNamespace() - $b->getNamespace();
3706                 }
3707         }
3708
3709         /**
3710          * Return a string representation of this title
3711          *
3712          * @return String representation of this title
3713          */
3714         public function __toString() {
3715                 return $this->getPrefixedText();
3716         }
3717
3718         /**
3719          * Check if page exists.  For historical reasons, this function simply
3720          * checks for the existence of the title in the page table, and will
3721          * thus return false for interwiki links, special pages and the like.
3722          * If you want to know if a title can be meaningfully viewed, you should
3723          * probably call the isKnown() method instead.
3724          *
3725          * @return Bool
3726          */
3727         public function exists() {
3728                 return $this->getArticleId() != 0;
3729         }
3730
3731         /**
3732          * Should links to this title be shown as potentially viewable (i.e. as
3733          * "bluelinks"), even if there's no record by this title in the page
3734          * table?
3735          *
3736          * This function is semi-deprecated for public use, as well as somewhat
3737          * misleadingly named.  You probably just want to call isKnown(), which
3738          * calls this function internally.
3739          *
3740          * (ISSUE: Most of these checks are cheap, but the file existence check
3741          * can potentially be quite expensive.  Including it here fixes a lot of
3742          * existing code, but we might want to add an optional parameter to skip
3743          * it and any other expensive checks.)
3744          *
3745          * @return Bool
3746          */
3747         public function isAlwaysKnown() {
3748                 if ( $this->mInterwiki != '' ) {
3749                         return true;  // any interwiki link might be viewable, for all we know
3750                 }
3751                 switch( $this->mNamespace ) {
3752                         case NS_MEDIA:
3753                         case NS_FILE:
3754                                 // file exists, possibly in a foreign repo
3755                                 return (bool)wfFindFile( $this );
3756                         case NS_SPECIAL:
3757                                 // valid special page
3758                                 return SpecialPage::exists( $this->getDBkey() );
3759                         case NS_MAIN:
3760                                 // selflink, possibly with fragment
3761                                 return $this->mDbkeyform == '';
3762                         case NS_MEDIAWIKI:
3763                                 // known system message
3764                                 return $this->getDefaultMessageText() !== false;
3765                         default:
3766                                 return false;
3767                 }
3768         }
3769
3770         /**
3771          * Does this title refer to a page that can (or might) be meaningfully
3772          * viewed?  In particular, this function may be used to determine if
3773          * links to the title should be rendered as "bluelinks" (as opposed to
3774          * "redlinks" to non-existent pages).
3775          *
3776          * @return Bool
3777          */
3778         public function isKnown() {
3779                 return $this->isAlwaysKnown() || $this->exists();
3780         }
3781
3782         /**
3783          * Does this page have source text?
3784          *
3785          * @return Boolean
3786          */
3787         public function hasSourceText() {
3788                 if ( $this->exists() ) {
3789                         return true;
3790                 }
3791
3792                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3793                         // If the page doesn't exist but is a known system message, default
3794                         // message content will be displayed, same for language subpages
3795                         return $this->getDefaultMessageText() !== false;
3796                 }
3797
3798                 return false;
3799         }
3800
3801         /**
3802          * Get the default message text or false if the message doesn't exist
3803          *
3804          * @return String or false
3805          */
3806         public function getDefaultMessageText() {
3807                 global $wgContLang;
3808
3809                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
3810                         return false;
3811                 }
3812
3813                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
3814                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
3815
3816                 if ( $message->exists() ) {
3817                         return $message->plain();
3818                 } else {
3819                         return false;
3820                 }
3821         }
3822
3823         /**
3824          * Is this in a namespace that allows actual pages?
3825          *
3826          * @return Bool
3827          * @internal note -- uses hardcoded namespace index instead of constants
3828          */
3829         public function canExist() {
3830                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3831         }
3832
3833         /**
3834          * Update page_touched timestamps and send squid purge messages for
3835          * pages linking to this title. May be sent to the job queue depending
3836          * on the number of links. Typically called on create and delete.
3837          */
3838         public function touchLinks() {
3839                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3840                 $u->doUpdate();
3841
3842                 if ( $this->getNamespace() == NS_CATEGORY ) {
3843                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3844                         $u->doUpdate();
3845                 }
3846         }
3847
3848         /**
3849          * Get the last touched timestamp
3850          *
3851          * @param $db DatabaseBase: optional db
3852          * @return String last-touched timestamp
3853          */
3854         public function getTouched( $db = null ) {
3855                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3856                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3857                 return $touched;
3858         }
3859
3860         /**
3861          * Get the timestamp when this page was updated since the user last saw it.
3862          *
3863          * @param $user User
3864          * @return String|Null
3865          */
3866         public function getNotificationTimestamp( $user = null ) {
3867                 global $wgUser, $wgShowUpdatedMarker;
3868                 // Assume current user if none given
3869                 if ( !$user ) {
3870                         $user = $wgUser;
3871                 }
3872                 // Check cache first
3873                 $uid = $user->getId();
3874                 // avoid isset here, as it'll return false for null entries
3875                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
3876                         return $this->mNotificationTimestamp[$uid];
3877                 }
3878                 if ( !$uid || !$wgShowUpdatedMarker ) {
3879                         return $this->mNotificationTimestamp[$uid] = false;
3880                 }
3881                 // Don't cache too much!
3882                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3883                         $this->mNotificationTimestamp = array();
3884                 }
3885                 $dbr = wfGetDB( DB_SLAVE );
3886                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3887                         'wl_notificationtimestamp',
3888                         array( 'wl_namespace' => $this->getNamespace(),
3889                                 'wl_title' => $this->getDBkey(),
3890                                 'wl_user' => $user->getId()
3891                         ),
3892                         __METHOD__
3893                 );
3894                 return $this->mNotificationTimestamp[$uid];
3895         }
3896
3897         /**
3898          * Get the trackback URL for this page
3899          *
3900          * @return String Trackback URL
3901          */
3902         public function trackbackURL() {
3903                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3904
3905                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3906                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3907         }
3908
3909         /**
3910          * Get the trackback RDF for this page
3911          *
3912          * @return String Trackback RDF
3913          */
3914         public function trackbackRDF() {
3915                 $url = htmlspecialchars( $this->getFullURL() );
3916                 $title = htmlspecialchars( $this->getText() );
3917                 $tburl = $this->trackbackURL();
3918
3919                 // Autodiscovery RDF is placed in comments so HTML validator
3920                 // won't barf. This is a rather icky workaround, but seems
3921                 // frequently used by this kind of RDF thingy.
3922                 //
3923                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3924                 return "<!--
3925 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3926                  xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3927                  xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3928 <rdf:Description
3929    rdf:about=\"$url\"
3930    dc:identifier=\"$url\"
3931    dc:title=\"$title\"
3932    trackback:ping=\"$tburl\" />
3933 </rdf:RDF>
3934 -->";
3935         }
3936
3937         /**
3938          * Generate strings used for xml 'id' names in monobook tabs
3939          *
3940          * @param $prepend string defaults to 'nstab-'
3941          * @return String XML 'id' name
3942          */
3943         public function getNamespaceKey( $prepend = 'nstab-' ) {
3944                 global $wgContLang;
3945                 // Gets the subject namespace if this title
3946                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
3947                 // Checks if cononical namespace name exists for namespace
3948                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
3949                         // Uses canonical namespace name
3950                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
3951                 } else {
3952                         // Uses text of namespace
3953                         $namespaceKey = $this->getSubjectNsText();
3954                 }
3955                 // Makes namespace key lowercase
3956                 $namespaceKey = $wgContLang->lc( $namespaceKey );
3957                 // Uses main
3958                 if ( $namespaceKey == '' ) {
3959                         $namespaceKey = 'main';
3960                 }
3961                 // Changes file to image for backwards compatibility
3962                 if ( $namespaceKey == 'file' ) {
3963                         $namespaceKey = 'image';
3964                 }
3965                 return $prepend . $namespaceKey;
3966         }
3967
3968         /**
3969          * Returns true if this is a special page.
3970          *
3971          * @return boolean
3972          */
3973         public function isSpecialPage() {
3974                 return $this->getNamespace() == NS_SPECIAL;
3975         }
3976
3977         /**
3978          * Returns true if this title resolves to the named special page
3979          *
3980          * @param $name String The special page name
3981          * @return boolean
3982          */
3983         public function isSpecial( $name ) {
3984                 if ( $this->getNamespace() == NS_SPECIAL ) {
3985                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
3986                         if ( $name == $thisName ) {
3987                                 return true;
3988                         }
3989                 }
3990                 return false;
3991         }
3992
3993         /**
3994          * If the Title refers to a special page alias which is not the local default, resolve
3995          * the alias, and localise the name as necessary.  Otherwise, return $this
3996          *
3997          * @return Title
3998          */
3999         public function fixSpecialName() {
4000                 if ( $this->getNamespace() == NS_SPECIAL ) {
4001                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
4002                         if ( $canonicalName ) {
4003                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
4004                                 if ( $localName != $this->mDbkeyform ) {
4005                                         return Title::makeTitle( NS_SPECIAL, $localName );
4006                                 }
4007                         }
4008                 }
4009                 return $this;
4010         }
4011
4012         /**
4013          * Is this Title in a namespace which contains content?
4014          * In other words, is this a content page, for the purposes of calculating
4015          * statistics, etc?
4016          *
4017          * @return Boolean
4018          */
4019         public function isContentPage() {
4020                 return MWNamespace::isContent( $this->getNamespace() );
4021         }
4022
4023         /**
4024          * Get all extant redirects to this Title
4025          *
4026          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4027          * @return Array of Title redirects to this title
4028          */
4029         public function getRedirectsHere( $ns = null ) {
4030                 $redirs = array();
4031
4032                 $dbr = wfGetDB( DB_SLAVE );
4033                 $where = array(
4034                         'rd_namespace' => $this->getNamespace(),
4035                         'rd_title' => $this->getDBkey(),
4036                         'rd_from = page_id'
4037                 );
4038                 if ( !is_null( $ns ) ) {
4039                         $where['page_namespace'] = $ns;
4040                 }
4041
4042                 $res = $dbr->select(
4043                         array( 'redirect', 'page' ),
4044                         array( 'page_namespace', 'page_title' ),
4045                         $where,
4046                         __METHOD__
4047                 );
4048
4049                 foreach ( $res as $row ) {
4050                         $redirs[] = self::newFromRow( $row );
4051                 }
4052                 return $redirs;
4053         }
4054
4055         /**
4056          * Check if this Title is a valid redirect target
4057          *
4058          * @return Bool
4059          */
4060         public function isValidRedirectTarget() {
4061                 global $wgInvalidRedirectTargets;
4062
4063                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4064                 if ( $this->isSpecial( 'Userlogout' ) ) {
4065                         return false;
4066                 }
4067
4068                 foreach ( $wgInvalidRedirectTargets as $target ) {
4069                         if ( $this->isSpecial( $target ) ) {
4070                                 return false;
4071                         }
4072                 }
4073
4074                 return true;
4075         }
4076
4077         /**
4078          * Get a backlink cache object
4079          *
4080          * @return object BacklinkCache
4081          */
4082         function getBacklinkCache() {
4083                 if ( is_null( $this->mBacklinkCache ) ) {
4084                         $this->mBacklinkCache = new BacklinkCache( $this );
4085                 }
4086                 return $this->mBacklinkCache;
4087         }
4088
4089         /**
4090          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4091          *
4092          * @return Boolean
4093          */
4094         public function canUseNoindex() {
4095                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4096
4097                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4098                         ? $wgContentNamespaces
4099                         : $wgExemptFromUserRobotsControl;
4100
4101                 return !in_array( $this->mNamespace, $bannedNamespaces );
4102
4103         }
4104
4105         /**
4106          * Returns restriction types for the current Title
4107          *
4108          * @return array applicable restriction types
4109          */
4110         public function getRestrictionTypes() {
4111                 global $wgRestrictionTypes;
4112
4113                 $types = $this->exists() ? $wgRestrictionTypes : array( 'create' );
4114
4115                 if ( $this->getNamespace() != NS_FILE ) {
4116                         $types = array_diff( $types, array( 'upload' ) );
4117                 }
4118
4119                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4120
4121                 return $types;
4122         }
4123
4124         /**
4125          * Returns the raw sort key to be used for categories, with the specified
4126          * prefix.  This will be fed to Collation::getSortKey() to get a
4127          * binary sortkey that can be used for actual sorting.
4128          *
4129          * @param $prefix string The prefix to be used, specified using
4130          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4131          *   prefix.
4132          * @return string
4133          */
4134         public function getCategorySortkey( $prefix = '' ) {
4135                 $unprefixed = $this->getText();
4136                 if ( $prefix !== '' ) {
4137                         # Separate with a line feed, so the unprefixed part is only used as
4138                         # a tiebreaker when two pages have the exact same prefix.
4139                         # In UCA, tab is the only character that can sort above LF
4140                         # so we strip both of them from the original prefix.
4141                         $prefix = strtr( $prefix, "\n\t", '  ' );
4142                         return "$prefix\n$unprefixed";
4143                 }
4144                 return $unprefixed;
4145         }
4146 }