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