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 of getTitleProtection
  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 \type{\string} The database key, which has underscores
  98          *      instead of spaces, possibly including namespace and
  99          *      interwiki prefixes
 100          * @return \type{Title} the new object, 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  The new object, 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                 /**
 142                  * Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 143                  */
 144                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 145
 146                 $t = new Title();
 147                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 148                 $t->mDefaultNamespace = $defaultNamespace;
 149
 150                 static $cachedcount = 0 ;
 151                 if ( $t->secureAndSplit() ) {
 152                         if ( $defaultNamespace == NS_MAIN ) {
 153                                 if ( $cachedcount >= self::CACHE_MAX ) {
 154                                         # Avoid memory leaks on mass operations...
 155                                         Title::$titleCache = array();
 156                                         $cachedcount = 0;
 157                                 }
 158                                 $cachedcount++;
 159                                 Title::$titleCache[$text] =& $t;
 160                         }
 161                         return $t;
 162                 } else {
 163                         $ret = null;
 164                         return $ret;
 165                 }
 166         }
 167
 168         /**
 169          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 170          *
 171          * Example of wrong and broken code:
 172          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 173          *
 174          * Example of right code:
 175          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 176          *
 177          * Create a new Title from URL-encoded text. Ensures that
 178          * the given title's length does not exceed the maximum.
 179          *
 180          * @param $url \type{\string} the title, as might be taken from a URL
 181          * @return \type{Title} the new object, or NULL on an error
 182          */
 183         public static function newFromURL( $url ) {
 184                 global $wgLegalTitleChars;
 185                 $t = new Title();
 186
 187                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 188                 # but some URLs used it as a space replacement and they still come
 189                 # from some external search tools.
 190                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 191                         $url = str_replace( '+', ' ', $url );
 192                 }
 193
 194                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 195                 if ( $t->secureAndSplit() ) {
 196                         return $t;
 197                 } else {
 198                         return null;
 199                 }
 200         }
 201
 202         /**
 203          * Create a new Title from an article ID
 204          *
 205          * @param $id \type{\int} the page_id corresponding to the Title to create
 206          * @param $flags \type{\int} use Title::GAID_FOR_UPDATE to use master
 207          * @return \type{Title} the new object, or NULL on an error
 208          */
 209         public static function newFromID( $id, $flags = 0 ) {
 210                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 211                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 212                 if ( $row !== false ) {
 213                         $title = Title::newFromRow( $row );
 214                 } else {
 215                         $title = null;
 216                 }
 217                 return $title;
 218         }
 219
 220         /**
 221          * Make an array of titles from an array of IDs
 222          *
 223          * @param $ids \type{\arrayof{\int}} Array of IDs
 224          * @return \type{\arrayof{Title}} Array of Titles
 225          */
 226         public static function newFromIDs( $ids ) {
 227                 if ( !count( $ids ) ) {
 228                         return array();
 229                 }
 230                 $dbr = wfGetDB( DB_SLAVE );
 231
 232                 $res = $dbr->select(
 233                         'page',
 234                         array(
 235                                 'page_namespace', 'page_title', 'page_id',
 236                                 'page_len', 'page_is_redirect', 'page_latest',
 237                         ),
 238                         array( 'page_id' => $ids ),
 239                         __METHOD__
 240                 );
 241
 242                 $titles = array();
 243                 foreach ( $res as $row ) {
 244                         $titles[] = Title::newFromRow( $row );
 245                 }
 246                 return $titles;
 247         }
 248
 249         /**
 250          * Make a Title object from a DB row
 251          *
 252          * @param $row \type{Row} (needs at least page_title,page_namespace)
 253          * @return \type{Title} corresponding Title
 254          */
 255         public static function newFromRow( $row ) {
 256                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 257
 258                 $t->mArticleID = isset( $row->page_id ) ? intval( $row->page_id ) : -1;
 259                 $t->mLength = isset( $row->page_len ) ? intval( $row->page_len ) : -1;
 260                 $t->mRedirect = isset( $row->page_is_redirect ) ? (bool)$row->page_is_redirect : null;
 261                 $t->mLatestID = isset( $row->page_latest ) ? intval( $row->page_latest ) : false;
 262
 263                 return $t;
 264         }
 265
 266         /**
 267          * Create a new Title from a namespace index and a DB key.
 268          * It's assumed that $ns and $title are *valid*, for instance when
 269          * they came directly from the database or a special page name.
 270          * For convenience, spaces are converted to underscores so that
 271          * eg user_text fields can be used directly.
 272          *
 273          * @param $ns \type{\int} the namespace of the article
 274          * @param $title \type{\string} the unprefixed database key form
 275          * @param $fragment \type{\string} The link fragment (after the "#")
 276          * @param $interwiki \type{\string} The interwiki prefix
 277          * @return \type{Title} the new object
 278          */
 279         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 280                 $t = new Title();
 281                 $t->mInterwiki = $interwiki;
 282                 $t->mFragment = $fragment;
 283                 $t->mNamespace = $ns = intval( $ns );
 284                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 285                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 286                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 287                 $t->mTextform = str_replace( '_', ' ', $title );
 288                 return $t;
 289         }
 290
 291         /**
 292          * Create a new Title from a namespace index and a DB key.
 293          * The parameters will be checked for validity, which is a bit slower
 294          * than makeTitle() but safer for user-provided data.
 295          *
 296          * @param $ns \type{\int} the namespace of the article
 297          * @param $title \type{\string} the database key form
 298          * @param $fragment \type{\string} The link fragment (after the "#")
 299          * @param $interwiki \type{\string} The interwiki prefix
 300          * @return \type{Title} the new object, or NULL on an error
 301          */
 302         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 303                 $t = new Title();
 304                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 305                 if ( $t->secureAndSplit() ) {
 306                         return $t;
 307                 } else {
 308                         return null;
 309                 }
 310         }
 311
 312         /**
 313          * Create a new Title for the Main Page
 314          *
 315          * @return \type{Title} the new object
 316          */
 317         public static function newMainPage() {
 318                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 319                 // Don't give fatal errors if the message is broken
 320                 if ( !$title ) {
 321                         $title = Title::newFromText( 'Main Page' );
 322                 }
 323                 return $title;
 324         }
 325
 326         /**
 327          * Extract a redirect destination from a string and return the
 328          * Title, or null if the text doesn't contain a valid redirect
 329          * This will only return the very next target, useful for
 330          * the redirect table and other checks that don't need full recursion
 331          *
 332          * @param $text \type{\string} Text with possible redirect
 333          * @return \type{Title} The corresponding Title
 334          */
 335         public static function newFromRedirect( $text ) {
 336                 return self::newFromRedirectInternal( $text );
 337         }
 338
 339         /**
 340          * Extract a redirect destination from a string and return the
 341          * Title, or null if the text doesn't contain a valid redirect
 342          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 343          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 344          *
 345          * @param $text \type{\string} Text with possible redirect
 346          * @return \type{Title} The corresponding Title
 347          */
 348         public static function newFromRedirectRecurse( $text ) {
 349                 $titles = self::newFromRedirectArray( $text );
 350                 return $titles ? array_pop( $titles ) : null;
 351         }
 352
 353         /**
 354          * Extract a redirect destination from a string and return an
 355          * array of Titles, or null if the text doesn't contain a valid redirect
 356          * The last element in the array is the final destination after all redirects
 357          * have been resolved (up to $wgMaxRedirects times)
 358          *
 359          * @param $text \type{\string} Text with possible redirect
 360          * @return \type{\array} Array of Titles, with the destination last
 361          */
 362         public static function newFromRedirectArray( $text ) {
 363                 global $wgMaxRedirects;
 364                 // are redirects disabled?
 365                 if ( $wgMaxRedirects < 1 ) {
 366                         return null;
 367                 }
 368                 $title = self::newFromRedirectInternal( $text );
 369                 if ( is_null( $title ) ) {
 370                         return null;
 371                 }
 372                 // recursive check to follow double redirects
 373                 $recurse = $wgMaxRedirects;
 374                 $titles = array( $title );
 375                 while ( --$recurse > 0 ) {
 376                         if ( $title->isRedirect() ) {
 377                                 $article = new Article( $title, 0 );
 378                                 $newtitle = $article->getRedirectTarget();
 379                         } else {
 380                                 break;
 381                         }
 382                         // Redirects to some special pages are not permitted
 383                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 384                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 385                                 $title = $newtitle;
 386                                 $titles[] = $newtitle;
 387                         } else {
 388                                 break;
 389                         }
 390                 }
 391                 return $titles;
 392         }
 393
 394         /**
 395          * Really extract the redirect destination
 396          * Do not call this function directly, use one of the newFromRedirect* functions above
 397          *
 398          * @param $text \type{\string} Text with possible redirect
 399          * @return \type{Title} The corresponding Title
 400          */
 401         protected static function newFromRedirectInternal( $text ) {
 402                 $redir = MagicWord::get( 'redirect' );
 403                 $text = trim( $text );
 404                 if ( $redir->matchStartAndRemove( $text ) ) {
 405                         // Extract the first link and see if it's usable
 406                         // Ensure that it really does come directly after #REDIRECT
 407                         // Some older redirects included a colon, so don't freak about that!
 408                         $m = array();
 409                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 410                                 // Strip preceding colon used to "escape" categories, etc.
 411                                 // and URL-decode links
 412                                 if ( strpos( $m[1], '%' ) !== false ) {
 413                                         // Match behavior of inline link parsing here;
 414                                         // don't interpret + as " " most of the time!
 415                                         // It might be safe to just use rawurldecode instead, though.
 416                                         $m[1] = urldecode( ltrim( $m[1], ':' ) );
 417                                 }
 418                                 $title = Title::newFromText( $m[1] );
 419                                 // If the title is a redirect to bad special pages or is invalid, return null
 420                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 421                                         return null;
 422                                 }
 423                                 return $title;
 424                         }
 425                 }
 426                 return null;
 427         }
 428
 429 # ----------------------------------------------------------------------------
 430 #       Static functions
 431 # ----------------------------------------------------------------------------
 432
 433         /**
 434          * Get the prefixed DB key associated with an ID
 435          *
 436          * @param $id \type{\int} the page_id of the article
 437          * @return \type{Title} an object representing the article, or NULL
 438          *  if no such article was found
 439          */
 440         public static function nameOf( $id ) {
 441                 $dbr = wfGetDB( DB_SLAVE );
 442
 443                 $s = $dbr->selectRow(
 444                         'page',
 445                         array( 'page_namespace', 'page_title' ),
 446                         array( 'page_id' => $id ),
 447                         __METHOD__
 448                 );
 449                 if ( $s === false ) {
 450                         return null;
 451                 }
 452
 453                 $n = self::makeName( $s->page_namespace, $s->page_title );
 454                 return $n;
 455         }
 456
 457         /**
 458          * Get a regex character class describing the legal characters in a link
 459          *
 460          * @return \type{\string} the list of characters, not delimited
 461          */
 462         public static function legalChars() {
 463                 global $wgLegalTitleChars;
 464                 return $wgLegalTitleChars;
 465         }
 466
 467         /**
 468          * Get a string representation of a title suitable for
 469          * including in a search index
 470          *
 471          * @param $ns \type{\int} a namespace index
 472          * @param $title \type{\string} text-form main part
 473          * @return \type{\string} a stripped-down title string ready for the
 474          *  search index
 475          */
 476         public static function indexTitle( $ns, $title ) {
 477                 global $wgContLang;
 478
 479                 $lc = SearchEngine::legalSearchChars() . '&#;';
 480                 $t = $wgContLang->normalizeForSearch( $title );
 481                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 482                 $t = $wgContLang->lc( $t );
 483
 484                 # Handle 's, s'
 485                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 486                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 487
 488                 $t = preg_replace( "/\\s+/", ' ', $t );
 489
 490                 if ( $ns == NS_FILE ) {
 491                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 492                 }
 493                 return trim( $t );
 494         }
 495
 496         /**
 497          * Make a prefixed DB key from a DB key and a namespace index
 498          *
 499          * @param $ns \type{\int} numerical representation of the namespace
 500          * @param $title \type{\string} the DB key form the title
 501          * @param $fragment \type{\string} The link fragment (after the "#")
 502          * @param $interwiki \type{\string} The interwiki prefix
 503          * @return \type{\string} the prefixed form of the title
 504          */
 505         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 506                 global $wgContLang;
 507
 508                 $namespace = $wgContLang->getNsText( $ns );
 509                 $name = $namespace == '' ? $title : "$namespace:$title";
 510                 if ( strval( $interwiki ) != '' ) {
 511                         $name = "$interwiki:$name";
 512                 }
 513                 if ( strval( $fragment ) != '' ) {
 514                         $name .= '#' . $fragment;
 515                 }
 516                 return $name;
 517         }
 518
 519         /**
 520          * Determine whether the object refers to a page within
 521          * this project.
 522          *
 523          * @return \type{\bool} TRUE if this is an in-project interwiki link
 524          *      or a wikilink, FALSE otherwise
 525          */
 526         public function isLocal() {
 527                 if ( $this->mInterwiki != '' ) {
 528                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 529                 } else {
 530                         return true;
 531                 }
 532         }
 533
 534         /**
 535          * Determine whether the object refers to a page within
 536          * this project and is transcludable.
 537          *
 538          * @return \type{\bool} TRUE if this is transcludable
 539          */
 540         public function isTrans() {
 541                 if ( $this->mInterwiki == '' ) {
 542                         return false;
 543                 }
 544
 545                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 546         }
 547
 548         /**
 549          * Returns the DB name of the distant wiki
 550          * which owns the object.
 551          *
 552          * @return \type{\string} the DB name
 553          */
 554         public function getTransWikiID() {
 555                 if ( $this->mInterwiki == '' ) {
 556                         return false;
 557                 }
 558
 559                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 560         }
 561
 562         /**
 563          * Escape a text fragment, say from a link, for a URL
 564          *
 565          * @param $fragment string containing a URL or link fragment (after the "#")
 566          * @return String: escaped string
 567          */
 568         static function escapeFragmentForURL( $fragment ) {
 569                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 570                 # fragments appear not to work in IE (at least up to 7) or in at least
 571                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 572                 # to care if they aren't encoded.
 573                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 574         }
 575
 576 # ----------------------------------------------------------------------------
 577 #       Other stuff
 578 # ----------------------------------------------------------------------------
 579
 580         /** Simple accessors */
 581         /**
 582          * Get the text form (spaces not underscores) of the main part
 583          *
 584          * @return \type{\string} Main part of the title
 585          */
 586         public function getText() { return $this->mTextform; }
 587
 588         /**
 589          * Get the URL-encoded form of the main part
 590          *
 591          * @return \type{\string} Main part of the title, URL-encoded
 592          */
 593         public function getPartialURL() { return $this->mUrlform; }
 594
 595         /**
 596          * Get the main part with underscores
 597          *
 598          * @return \type{\string} Main part of the title, with underscores
 599          */
 600         public function getDBkey() { return $this->mDbkeyform; }
 601
 602         /**
 603          * Get the namespace index, i.e.\ one of the NS_xxxx constants.
 604          *
 605          * @return \type{\int} Namespace index
 606          */
 607         public function getNamespace() { return $this->mNamespace; }
 608
 609         /**
 610          * Get the namespace text
 611          *
 612          * @return \type{\string} Namespace text
 613          */
 614         public function getNsText() {
 615                 global $wgContLang;
 616
 617                 if ( $this->mInterwiki != '' ) {
 618                         // This probably shouldn't even happen. ohh man, oh yuck.
 619                         // But for interwiki transclusion it sometimes does.
 620                         // Shit. Shit shit shit.
 621                         //
 622                         // Use the canonical namespaces if possible to try to
 623                         // resolve a foreign namespace.
 624                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 625                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 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 \type{\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 \type{\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 \type{\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 \type{\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 \type{\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 \type{\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 \type{\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 \type{\int} Default namespace index
 699          */
 700         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 701
 702         /**
 703          * Get title for search index
 704          *
 705          * @return \type{\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 \type{\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 \type{\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 \type{\string} the prefixed title, with spaces and
 744          *  the fragment, including '#'
 745          */
 746         public function getFullText() {
 747                 $text = $this->getPrefixedText();
 748                 if ( $this->mFragment != '' ) {
 749                         $text .= '#' . $this->mFragment;
 750                 }
 751                 return $text;
 752         }
 753
 754         /**
 755          * Get the base name, i.e. the leftmost parts before the /
 756          *
 757          * @return \type{\string} Base name
 758          */
 759         public function getBaseText() {
 760                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 761                         return $this->getText();
 762                 }
 763
 764                 $parts = explode( '/', $this->getText() );
 765                 # Don't discard the real title if there's no subpage involved
 766                 if ( count( $parts ) > 1 ) {
 767                         unset( $parts[count( $parts ) - 1] );
 768                 }
 769                 return implode( '/', $parts );
 770         }
 771
 772         /**
 773          * Get the lowest-level subpage name, i.e. the rightmost part after /
 774          *
 775          * @return \type{\string} Subpage name
 776          */
 777         public function getSubpageText() {
 778                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 779                         return( $this->mTextform );
 780                 }
 781                 $parts = explode( '/', $this->mTextform );
 782                 return( $parts[count( $parts ) - 1] );
 783         }
 784
 785         /**
 786          * Get a URL-encoded form of the subpage text
 787          *
 788          * @return \type{\string} URL-encoded subpage name
 789          */
 790         public function getSubpageUrlForm() {
 791                 $text = $this->getSubpageText();
 792                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 793                 return( $text );
 794         }
 795
 796         /**
 797          * Get a URL-encoded title (not an actual URL) including interwiki
 798          *
 799          * @return \type{\string} the URL-encoded form
 800          */
 801         public function getPrefixedURL() {
 802                 $s = $this->prefix( $this->mDbkeyform );
 803                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 804                 return $s;
 805         }
 806
 807         /**
 808          * Get a real URL referring to this title, with interwiki link and
 809          * fragment
 810          *
 811          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 812          *   links. Can be specified as an associative array as well, e.g.,
 813          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 814          * @param $variant \type{\string} language variant of url (for sr, zh..)
 815          * @return \type{\string} the URL
 816          */
 817         public function getFullURL( $query = '', $variant = false ) {
 818                 global $wgServer, $wgRequest;
 819
 820                 if ( is_array( $query ) ) {
 821                         $query = wfArrayToCGI( $query );
 822                 }
 823
 824                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 825                 if ( !$interwiki ) {
 826                         $url = $this->getLocalURL( $query, $variant );
 827
 828                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 829                         // Correct fix would be to move the prepending elsewhere.
 830                         if ( $wgRequest->getVal( 'action' ) != 'render' ) {
 831                                 $url = $wgServer . $url;
 832                         }
 833                 } else {
 834                         $baseUrl = $interwiki->getURL();
 835
 836                         $namespace = wfUrlencode( $this->getNsText() );
 837                         if ( $namespace != '' ) {
 838                                 # Can this actually happen? Interwikis shouldn't be parsed.
 839                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 840                                 $namespace .= ':';
 841                         }
 842                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 843                         $url = wfAppendQuery( $url, $query );
 844                 }
 845
 846                 # Finally, add the fragment.
 847                 $url .= $this->getFragmentForURL();
 848
 849                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 850                 return $url;
 851         }
 852
 853         /**
 854          * Get a URL with no fragment or server name.  If this page is generated
 855          * with action=render, $wgServer is prepended.
 856          *
 857          * @param $query Mixed: an optional query string; if not specified,
 858          *   $wgArticlePath will be used.  Can be specified as an associative array
 859          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 860          *   URL-escaped).
 861          * @param $variant \type{\string} language variant of url (for sr, zh..)
 862          * @return \type{\string} the URL
 863          */
 864         public function getLocalURL( $query = '', $variant = false ) {
 865                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 866                 global $wgVariantArticlePath, $wgContLang;
 867
 868                 if ( is_array( $query ) ) {
 869                         $query = wfArrayToCGI( $query );
 870                 }
 871
 872                 if ( $this->isExternal() ) {
 873                         $url = $this->getFullURL();
 874                         if ( $query ) {
 875                                 // This is currently only used for edit section links in the
 876                                 // context of interwiki transclusion. In theory we should
 877                                 // append the query to the end of any existing query string,
 878                                 // but interwiki transclusion is already broken in that case.
 879                                 $url .= "?$query";
 880                         }
 881                 } else {
 882                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 883                         if ( $query == '' ) {
 884                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 885                                         if ( !$wgVariantArticlePath ) {
 886                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 887                                         } else {
 888                                                 $variantArticlePath = $wgVariantArticlePath;
 889                                         }
 890                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 891                                         $url = str_replace( '$1', $dbkey, $url  );
 892                                 } else {
 893                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 894                                 }
 895                         } else {
 896                                 global $wgActionPaths;
 897                                 $url = false;
 898                                 $matches = array();
 899                                 if ( !empty( $wgActionPaths ) &&
 900                                         preg_match( '/^(.*&|)action=([^&]*)(&(.*)|)$/', $query, $matches ) )
 901                                 {
 902                                         $action = urldecode( $matches[2] );
 903                                         if ( isset( $wgActionPaths[$action] ) ) {
 904                                                 $query = $matches[1];
 905                                                 if ( isset( $matches[4] ) ) {
 906                                                         $query .= $matches[4];
 907                                                 }
 908                                                 $url = str_replace( '$1', $dbkey, $wgActionPaths[$action] );
 909                                                 if ( $query != '' ) {
 910                                                         $url = wfAppendQuery( $url, $query );
 911                                                 }
 912                                         }
 913                                 }
 914                                 if ( $url === false ) {
 915                                         if ( $query == '-' ) {
 916                                                 $query = '';
 917                                         }
 918                                         $url = "{$wgScript}?title={$dbkey}&{$query}";
 919                                 }
 920                         }
 921
 922                         // FIXME: this causes breakage in various places when we
 923                         // actually expected a local URL and end up with dupe prefixes.
 924                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 925                                 $url = $wgServer . $url;
 926                         }
 927                 }
 928                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 929                 return $url;
 930         }
 931
 932         /**
 933          * Get a URL that's the simplest URL that will be valid to link, locally,
 934          * to the current Title.  It includes the fragment, but does not include
 935          * the server unless action=render is used (or the link is external).  If
 936          * there's a fragment but the prefixed text is empty, we just return a link
 937          * to the fragment.
 938          *
 939          * The result obviously should not be URL-escaped, but does need to be
 940          * HTML-escaped if it's being output in HTML.
 941          *
 942          * @param $query \type{\arrayof{\string}} An associative array of key => value pairs for the
 943          *   query string.  Keys and values will be escaped.
 944          * @param $variant \type{\string} Language variant of URL (for sr, zh..).  Ignored
 945          *   for external links.  Default is "false" (same variant as current page,
 946          *   for anonymous users).
 947          * @return \type{\string} the URL
 948          */
 949         public function getLinkUrl( $query = array(), $variant = false ) {
 950                 wfProfileIn( __METHOD__ );
 951                 if ( $this->isExternal() ) {
 952                         $ret = $this->getFullURL( $query );
 953                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 954                         $ret = $this->getFragmentForURL();
 955                 } else {
 956                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 957                 }
 958                 wfProfileOut( __METHOD__ );
 959                 return $ret;
 960         }
 961
 962         /**
 963          * Get an HTML-escaped version of the URL form, suitable for
 964          * using in a link, without a server name or fragment
 965          *
 966          * @param $query \type{\string} an optional query string
 967          * @return \type{\string} the URL
 968          */
 969         public function escapeLocalURL( $query = '' ) {
 970                 return htmlspecialchars( $this->getLocalURL( $query ) );
 971         }
 972
 973         /**
 974          * Get an HTML-escaped version of the URL form, suitable for
 975          * using in a link, including the server name and fragment
 976          *
 977          * @param $query \type{\string} an optional query string
 978          * @return \type{\string} the URL
 979          */
 980         public function escapeFullURL( $query = '' ) {
 981                 return htmlspecialchars( $this->getFullURL( $query ) );
 982         }
 983
 984         /**
 985          * Get the URL form for an internal link.
 986          * - Used in various Squid-related code, in case we have a different
 987          * internal hostname for the server from the exposed one.
 988          *
 989          * @param $query \type{\string} an optional query string
 990          * @param $variant \type{\string} language variant of url (for sr, zh..)
 991          * @return \type{\string} the URL
 992          */
 993         public function getInternalURL( $query = '', $variant = false ) {
 994                 global $wgInternalServer;
 995                 $url = $wgInternalServer . $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 \type{\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 \type{\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 \type{\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 \type{\string} Action to check (default: edit)
1038          * @return \type{\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 \type{\string} the action the page is protected from,
1064          * by default checks all actions.
1065          * @return \type{\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 \type{\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 \type{\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 \type{\string} action that permission needs to be checked for
1138          * @return \type{\bool}
1139          */
1140         public function quickUserCan( $action ) {
1141                 return $this->userCan( $action, false );
1142         }
1143
1144         /**
1145          * Determines if $wgUser is unable to edit this page because it has been protected
1146          * by $wgNamespaceProtection.
1147          *
1148          * @return \type{\bool}
1149          */
1150         public function isNamespaceProtected() {
1151                 global $wgNamespaceProtection, $wgUser;
1152                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1153                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1154                                 if ( $right != '' && !$wgUser->isAllowed( $right ) ) {
1155                                         return true;
1156                                 }
1157                         }
1158                 }
1159                 return false;
1160         }
1161
1162         /**
1163          * Can $wgUser perform $action on this page?
1164          *
1165          * @param $action \type{\string} action that permission needs to be checked for
1166          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1167          * @return \type{\bool}
1168          */
1169         public function userCan( $action, $doExpensiveQueries = true ) {
1170                 global $wgUser;
1171                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1172         }
1173
1174         /**
1175          * Can $user perform $action on this page?
1176          *
1177          * FIXME: This *does not* check throttles (User::pingLimiter()).
1178          *
1179          * @param $action \type{\string}action that permission needs to be checked for
1180          * @param $user \type{User} user to check
1181          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1182          * @param $ignoreErrors \type{\arrayof{\string}} Set this to a list of message keys whose corresponding errors may be ignored.
1183          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1184          */
1185         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1186                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1187
1188                 // Remove the errors being ignored.
1189                 foreach ( $errors as $index => $error ) {
1190                         $error_key = is_array( $error ) ? $error[0] : $error;
1191
1192                         if ( in_array( $error_key, $ignoreErrors ) ) {
1193                                 unset( $errors[$index] );
1194                         }
1195                 }
1196
1197                 return $errors;
1198         }
1199
1200         /**
1201          * Permissions checks that fail most often, and which are easiest to test.
1202          *
1203          * @param $action String the action to check
1204          * @param $user User user to check
1205          * @param $errors Array list of current errors
1206          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1207          * @param $short Boolean short circuit on first error
1208          *
1209          * @return Array list of errors
1210          */
1211         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1212                 if ( $action == 'create' ) {
1213                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1214                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1215                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1216                         }
1217                 } elseif ( $action == 'move' ) {
1218                         if ( !$user->isAllowed( 'move-rootuserpages' )
1219                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1220                                 // Show user page-specific message only if the user can move other pages
1221                                 $errors[] = array( 'cant-move-user-page' );
1222                         }
1223
1224                         // Check if user is allowed to move files if it's a file
1225                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1226                                 $errors[] = array( 'movenotallowedfile' );
1227                         }
1228
1229                         if ( !$user->isAllowed( 'move' ) ) {
1230                                 // User can't move anything
1231                                 global $wgGroupPermissions;
1232                                 $userCanMove = false;
1233                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1234                                         $userCanMove = $wgGroupPermissions['user']['move'];
1235                                 }
1236                                 $autoconfirmedCanMove = false;
1237                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1238                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1239                                 }
1240                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1241                                         // custom message if logged-in users without any special rights can move
1242                                         $errors[] = array( 'movenologintext' );
1243                                 } else {
1244                                         $errors[] = array( 'movenotallowed' );
1245                                 }
1246                         }
1247                 } elseif ( $action == 'move-target' ) {
1248                         if ( !$user->isAllowed( 'move' ) ) {
1249                                 // User can't move anything
1250                                 $errors[] = array( 'movenotallowed' );
1251                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1252                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1253                                 // Show user page-specific message only if the user can move other pages
1254                                 $errors[] = array( 'cant-move-to-user-page' );
1255                         }
1256                 } elseif ( !$user->isAllowed( $action ) ) {
1257                         // We avoid expensive display logic for quickUserCan's and such
1258                         $groups = false;
1259                         if ( !$short ) {
1260                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1261                                         User::getGroupsWithPermission( $action ) );
1262                         }
1263
1264                         if ( $groups ) {
1265                                 global $wgLang;
1266                                 $return = array(
1267                                         'badaccess-groups',
1268                                         $wgLang->commaList( $groups ),
1269                                         count( $groups )
1270                                 );
1271                         } else {
1272                                 $return = array( 'badaccess-group0' );
1273                         }
1274                         $errors[] = $return;
1275                 }
1276
1277                 return $errors;
1278         }
1279
1280         /**
1281          * Add the resulting error code to the errors array
1282          *
1283          * @param $errors Array list of current errors
1284          * @param $result Mixed result of errors
1285          *
1286          * @return Array list of errors
1287          */
1288         private function resultToError( $errors, $result ) {
1289                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1290                         // A single array representing an error
1291                         $errors[] = $result;
1292                 } else if ( is_array( $result ) && is_array( $result[0] ) ) {
1293                         // A nested array representing multiple errors
1294                         $errors = array_merge( $errors, $result );
1295                 } else if ( $result !== '' && is_string( $result ) ) {
1296                         // A string representing a message-id
1297                         $errors[] = array( $result );
1298                 } else if ( $result === false ) {
1299                         // a generic "We don't want them to do that"
1300                         $errors[] = array( 'badaccess-group0' );
1301                 }
1302                 return $errors;
1303         }
1304
1305         /**
1306          * Check various permission hooks
1307          * @see checkQuickPermissions for parameter information
1308          */
1309         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1310                 // Use getUserPermissionsErrors instead
1311                 $result = '';
1312                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1313                         return $result ? array() : array( array( 'badaccess-group0' ) );
1314                 }
1315                 // Check getUserPermissionsErrors hook
1316                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1317                         $errors = $this->resultToError( $errors, $result );
1318                 }
1319                 // Check getUserPermissionsErrorsExpensive hook
1320                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1321                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1322                         $errors = $this->resultToError( $errors, $result );
1323                 }
1324
1325                 return $errors;
1326         }
1327
1328         /**
1329          * Check permissions on special pages & namespaces
1330          * @see checkQuickPermissions for parameter information
1331          */
1332         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1333                 # Only 'createaccount' and 'execute' can be performed on
1334                 # special pages, which don't actually exist in the DB.
1335                 $specialOKActions = array( 'createaccount', 'execute' );
1336                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1337                         $errors[] = array( 'ns-specialprotected' );
1338                 }
1339
1340                 # Check $wgNamespaceProtection for restricted namespaces
1341                 if ( $this->isNamespaceProtected() ) {
1342                         $ns = $this->mNamespace == NS_MAIN ?
1343                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1344                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1345                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1346                 }
1347
1348                 return $errors;
1349         }
1350
1351         /**
1352          * Check CSS/JS sub-page permissions
1353          * @see checkQuickPermissions for parameter information
1354          */
1355         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1356                 # Protect css/js subpages of user pages
1357                 # XXX: this might be better using restrictions
1358                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssSubpage()
1359                 #      and $this->userCanEditJsSubpage() from working
1360                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1361                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1362                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1363                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1364                                 $errors[] = array( 'customcssjsprotected' );
1365                         } else if ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1366                                 $errors[] = array( 'customcssjsprotected' );
1367                         }
1368                 }
1369
1370                 return $errors;
1371         }
1372
1373         /**
1374          * Check against page_restrictions table requirements on this
1375          * page. The user must possess all required rights for this
1376          * action.
1377          * @see checkQuickPermissions for parameter information
1378          */
1379         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1380                 foreach ( $this->getRestrictions( $action ) as $right ) {
1381                         // Backwards compatibility, rewrite sysop -> protect
1382                         if ( $right == 'sysop' ) {
1383                                 $right = 'protect';
1384                         }
1385                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1386                                 // Users with 'editprotected' permission can edit protected pages
1387                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected' ) ) {
1388                                         // Users with 'editprotected' permission cannot edit protected pages
1389                                         // with cascading option turned on.
1390                                         if ( $this->mCascadeRestriction ) {
1391                                                 $errors[] = array( 'protectedpagetext', $right );
1392                                         }
1393                                 } else {
1394                                         $errors[] = array( 'protectedpagetext', $right );
1395                                 }
1396                         }
1397                 }
1398
1399                 return $errors;
1400         }
1401
1402         /**
1403          * Check restrictions on cascading pages.
1404          * @see checkQuickPermissions for parameter information
1405          */
1406         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1407                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1408                         # We /could/ use the protection level on the source page, but it's
1409                         # fairly ugly as we have to establish a precedence hierarchy for pages
1410                         # included by multiple cascade-protected pages. So just restrict
1411                         # it to people with 'protect' permission, as they could remove the
1412                         # protection anyway.
1413                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1414                         # Cascading protection depends on more than this page...
1415                         # Several cascading protected pages may include this page...
1416                         # Check each cascading level
1417                         # This is only for protection restrictions, not for all actions
1418                         if ( isset( $restrictions[$action] ) ) {
1419                                 foreach ( $restrictions[$action] as $right ) {
1420                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1421                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1422                                                 $pages = '';
1423                                                 foreach ( $cascadingSources as $page )
1424                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1425                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1426                                         }
1427                                 }
1428                         }
1429                 }
1430
1431                 return $errors;
1432         }
1433
1434         /**
1435          * Check action permissions not already checked in checkQuickPermissions
1436          * @see checkQuickPermissions for parameter information
1437          */
1438         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1439                 if ( $action == 'protect' ) {
1440                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1441                                 // If they can't edit, they shouldn't protect.
1442                                 $errors[] = array( 'protect-cantedit' );
1443                         }
1444                 } elseif ( $action == 'create' ) {
1445                         $title_protection = $this->getTitleProtection();
1446                         if( $title_protection ) {
1447                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1448                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1449                                 }
1450                                 if( $title_protection['pt_create_perm'] == '' || !$user->isAllowed( $title_protection['pt_create_perm'] ) ) {
1451                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1452                                 }
1453                         }
1454                 } elseif ( $action == 'move' ) {
1455                         // Check for immobile pages
1456                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1457                                 // Specific message for this case
1458                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1459                         } elseif ( !$this->isMovable() ) {
1460                                 // Less specific message for rarer cases
1461                                 $errors[] = array( 'immobile-page' );
1462                         }
1463                 } elseif ( $action == 'move-target' ) {
1464                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1465                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1466                         } elseif ( !$this->isMovable() ) {
1467                                 $errors[] = array( 'immobile-target-page' );
1468                         }
1469                 }
1470                 return $errors;
1471         }
1472
1473         /**
1474          * Check that the user isn't blocked from editting.
1475          * @see checkQuickPermissions for parameter information
1476          */
1477         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1478                 if( $short ) {
1479                         return $errors;
1480                 }
1481
1482                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1483
1484                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1485                         $errors[] = array( 'confirmedittext' );
1486                 }
1487
1488                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1489                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1490                         $block = $user->mBlock;
1491
1492                         // This is from OutputPage::blockedPage
1493                         // Copied at r23888 by werdna
1494
1495                         $id = $user->blockedBy();
1496                         $reason = $user->blockedFor();
1497                         if ( $reason == '' ) {
1498                                 $reason = wfMsg( 'blockednoreason' );
1499                         }
1500                         $ip = wfGetIP();
1501
1502                         if ( is_numeric( $id ) ) {
1503                                 $name = User::whoIs( $id );
1504                         } else {
1505                                 $name = $id;
1506                         }
1507
1508                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1509                         $blockid = $block->mId;
1510                         $blockExpiry = $user->mBlock->mExpiry;
1511                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1512                         if ( $blockExpiry == 'infinity' ) {
1513                                 // Entry in database (table ipblocks) is 'infinity' but 'ipboptions' uses 'infinite' or 'indefinite'
1514                                 $scBlockExpiryOptions = wfMsg( 'ipboptions' );
1515
1516                                 foreach ( explode( ',', $scBlockExpiryOptions ) as $option ) {
1517                                         if ( !strpos( $option, ':' ) )
1518                                                 continue;
1519
1520                                         list( $show, $value ) = explode( ':', $option );
1521
1522                                         if ( $value == 'infinite' || $value == 'indefinite' ) {
1523                                                 $blockExpiry = $show;
1524                                                 break;
1525                                         }
1526                                 }
1527                         } else {
1528                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1529                         }
1530
1531                         $intended = $user->mBlock->mAddress;
1532
1533                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1534                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1535                 }
1536
1537                 return $errors;
1538         }
1539
1540         /**
1541          * Can $user perform $action on this page? This is an internal function,
1542          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1543          * checks on wfReadOnly() and blocks)
1544          *
1545          * @param $action \type{\string} action that permission needs to be checked for
1546          * @param $user \type{User} user to check
1547          * @param $doExpensiveQueries \type{\bool} Set this to false to avoid doing unnecessary queries.
1548          * @param $short \type{\bool} Set this to true to stop after the first permission error.
1549          * @return \type{\array} Array of arrays of the arguments to wfMsg to explain permissions problems.
1550          */
1551         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1552                 wfProfileIn( __METHOD__ );
1553
1554                 $errors = array();
1555                 $checks = array(
1556                         'checkQuickPermissions',
1557                         'checkPermissionHooks',
1558                         'checkSpecialsAndNSPermissions',
1559                         'checkCSSandJSPermissions',
1560                         'checkPageRestrictions',
1561                         'checkCascadingSourcesRestrictions',
1562                         'checkActionPermissions',
1563                         'checkUserBlock'
1564                 );
1565
1566                 while( count( $checks ) > 0 &&
1567                            !( $short && count( $errors ) > 0 ) ) {
1568                         $method = array_shift( $checks );
1569                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1570                 }
1571
1572                 wfProfileOut( __METHOD__ );
1573                 return $errors;
1574         }
1575
1576         /**
1577          * Is this title subject to title protection?
1578          *
1579          * @return \type{\mixed} An associative array representing any existent title
1580          *   protection, or false if there's none.
1581          */
1582         private function getTitleProtection() {
1583                 // Can't protect pages in special namespaces
1584                 if ( $this->getNamespace() < 0 ) {
1585                         return false;
1586                 }
1587
1588                 // Can't protect pages that exist.
1589                 if ( $this->exists() ) {
1590                         return false;
1591                 }
1592
1593                 if ( !isset( $this->mTitleProtection ) ) {
1594                         $dbr = wfGetDB( DB_SLAVE );
1595                         $res = $dbr->select( 'protected_titles', '*',
1596                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1597                                 __METHOD__ );
1598
1599                         // fetchRow returns false if there are no rows.
1600                         $this->mTitleProtection = $dbr->fetchRow( $res );
1601                 }
1602                 return $this->mTitleProtection;
1603         }
1604
1605         /**
1606          * Update the title protection status
1607          *
1608          * @param $create_perm \type{\string} Permission required for creation
1609          * @param $reason \type{\string} Reason for protection
1610          * @param $expiry \type{\string} Expiry timestamp
1611          * @return boolean true
1612          */
1613         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1614                 global $wgUser, $wgContLang;
1615
1616                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1617                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1618                         // No change
1619                         return true;
1620                 }
1621
1622                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1623
1624                 $dbw = wfGetDB( DB_MASTER );
1625
1626                 $encodedExpiry = Block::encodeExpiry( $expiry, $dbw );
1627
1628                 $expiry_description = '';
1629                 if ( $encodedExpiry != 'infinity' ) {
1630                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1631                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1632                 } else {
1633                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1634                 }
1635
1636                 # Update protection table
1637                 if ( $create_perm != '' ) {
1638                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1639                                 array(
1640                                         'pt_namespace' => $namespace,
1641                                         'pt_title' => $title,
1642                                         'pt_create_perm' => $create_perm,
1643                                         'pt_timestamp' => Block::encodeExpiry( wfTimestampNow(), $dbw ),
1644                                         'pt_expiry' => $encodedExpiry,
1645                                         'pt_user' => $wgUser->getId(),
1646                                         'pt_reason' => $reason,
1647                                 ), __METHOD__
1648                         );
1649                 } else {
1650                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1651                                 'pt_title' => $title ), __METHOD__ );
1652                 }
1653                 # Update the protection log
1654                 if ( $dbw->affectedRows() ) {
1655                         $log = new LogPage( 'protect' );
1656
1657                         if ( $create_perm ) {
1658                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1659                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1660                         } else {
1661                                 $log->addEntry( 'unprotect', $this, $reason );
1662                         }
1663                 }
1664
1665                 return true;
1666         }
1667
1668         /**
1669          * Remove any title protection due to page existing
1670          */
1671         public function deleteTitleProtection() {
1672                 $dbw = wfGetDB( DB_MASTER );
1673
1674                 $dbw->delete(
1675                         'protected_titles',
1676                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1677                         __METHOD__
1678                 );
1679         }
1680
1681         /**
1682          * Would anybody with sufficient privileges be able to move this page?
1683          * Some pages just aren't movable.
1684          *
1685          * @return \type{\bool} TRUE or FALSE
1686          */
1687         public function isMovable() {
1688                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1689         }
1690
1691         /**
1692          * Can $wgUser read this page?
1693          *
1694          * @return \type{\bool}
1695          * @todo fold these checks into userCan()
1696          */
1697         public function userCanRead() {
1698                 global $wgUser, $wgGroupPermissions;
1699
1700                 static $useShortcut = null;
1701
1702                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1703                 if ( is_null( $useShortcut ) ) {
1704                         global $wgRevokePermissions;
1705                         $useShortcut = true;
1706                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1707                                 # Not a public wiki, so no shortcut
1708                                 $useShortcut = false;
1709                         } elseif ( !empty( $wgRevokePermissions ) ) {
1710                                 /*
1711                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1712                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1713                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1714                                  * reading is allowed.
1715                                  */
1716                                 foreach ( $wgRevokePermissions as $perms ) {
1717                                         if ( !empty( $perms['read'] ) ) {
1718                                                 # We might be removing the read right from the user, so no shortcut
1719                                                 $useShortcut = false;
1720                                                 break;
1721                                         }
1722                                 }
1723                         }
1724                 }
1725
1726                 $result = null;
1727                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1728                 if ( $result !== null ) {
1729                         return $result;
1730                 }
1731
1732                 # Shortcut for public wikis, allows skipping quite a bit of code
1733                 if ( $useShortcut ) {
1734                         return true;
1735                 }
1736
1737                 if ( $wgUser->isAllowed( 'read' ) ) {
1738                         return true;
1739                 } else {
1740                         global $wgWhitelistRead;
1741
1742                         /**
1743                          * Always grant access to the login page.
1744                          * Even anons need to be able to log in.
1745                         */
1746                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1747                                 return true;
1748                         }
1749
1750                         /**
1751                          * Bail out if there isn't whitelist
1752                          */
1753                         if ( !is_array( $wgWhitelistRead ) ) {
1754                                 return false;
1755                         }
1756
1757                         /**
1758                          * Check for explicit whitelisting
1759                          */
1760                         $name = $this->getPrefixedText();
1761                         $dbName = $this->getPrefixedDBKey();
1762                         // Check with and without underscores
1763                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1764                                 return true;
1765
1766                         /**
1767                          * Old settings might have the title prefixed with
1768                          * a colon for main-namespace pages
1769                          */
1770                         if ( $this->getNamespace() == NS_MAIN ) {
1771                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1772                                         return true;
1773                                 }
1774                         }
1775
1776                         /**
1777                          * If it's a special page, ditch the subpage bit
1778                          * and check again
1779                          */
1780                         if ( $this->getNamespace() == NS_SPECIAL ) {
1781                                 $name = $this->getDBkey();
1782                                 list( $name, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $name );
1783                                 if ( $name === false ) {
1784                                         # Invalid special page, but we show standard login required message
1785                                         return false;
1786                                 }
1787
1788                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1789                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1790                                         return true;
1791                                 }
1792                         }
1793
1794                 }
1795                 return false;
1796         }
1797
1798         /**
1799          * Is this a talk page of some sort?
1800          *
1801          * @return \type{\bool}
1802          */
1803         public function isTalkPage() {
1804                 return MWNamespace::isTalk( $this->getNamespace() );
1805         }
1806
1807         /**
1808          * Is this a subpage?
1809          *
1810          * @return \type{\bool}
1811          */
1812         public function isSubpage() {
1813                 return MWNamespace::hasSubpages( $this->mNamespace )
1814                         ? strpos( $this->getText(), '/' ) !== false
1815                         : false;
1816         }
1817
1818         /**
1819          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1820          *
1821          * @return \type{\bool}
1822          */
1823         public function hasSubpages() {
1824                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1825                         # Duh
1826                         return false;
1827                 }
1828
1829                 # We dynamically add a member variable for the purpose of this method
1830                 # alone to cache the result.  There's no point in having it hanging
1831                 # around uninitialized in every Title object; therefore we only add it
1832                 # if needed and don't declare it statically.
1833                 if ( isset( $this->mHasSubpages ) ) {
1834                         return $this->mHasSubpages;
1835                 }
1836
1837                 $subpages = $this->getSubpages( 1 );
1838                 if ( $subpages instanceof TitleArray ) {
1839                         return $this->mHasSubpages = (bool)$subpages->count();
1840                 }
1841                 return $this->mHasSubpages = false;
1842         }
1843
1844         /**
1845          * Get all subpages of this page.
1846          *
1847          * @param $limit Maximum number of subpages to fetch; -1 for no limit
1848          * @return mixed TitleArray, or empty array if this page's namespace
1849          *  doesn't allow subpages
1850          */
1851         public function getSubpages( $limit = -1 ) {
1852                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1853                         return array();
1854                 }
1855
1856                 $dbr = wfGetDB( DB_SLAVE );
1857                 $conds['page_namespace'] = $this->getNamespace();
1858                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1859                 $options = array();
1860                 if ( $limit > -1 ) {
1861                         $options['LIMIT'] = $limit;
1862                 }
1863                 return $this->mSubpages = TitleArray::newFromResult(
1864                         $dbr->select( 'page',
1865                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1866                                 $conds,
1867                                 __METHOD__,
1868                                 $options
1869                         )
1870                 );
1871         }
1872
1873         /**
1874          * Could this page contain custom CSS or JavaScript, based
1875          * on the title?
1876          *
1877          * @return \type{\bool}
1878          */
1879         public function isCssOrJsPage() {
1880                 return $this->mNamespace == NS_MEDIAWIKI
1881                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1882         }
1883
1884         /**
1885          * Is this a .css or .js subpage of a user page?
1886          * @return \type{\bool}
1887          */
1888         public function isCssJsSubpage() {
1889                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1890         }
1891
1892         /**
1893          * Is this a *valid* .css or .js subpage of a user page?
1894          * Check that the corresponding skin exists
1895          *
1896          * @return \type{\bool}
1897          */
1898         public function isValidCssJsSubpage() {
1899                 if ( $this->isCssJsSubpage() ) {
1900                         $name = $this->getSkinFromCssJsSubpage();
1901                         if ( $name == 'common' ) {
1902                                 return true;
1903                         }
1904                         $skinNames = Skin::getSkinNames();
1905                         return array_key_exists( $name, $skinNames );
1906                 } else {
1907                         return false;
1908                 }
1909         }
1910
1911         /**
1912          * Trim down a .css or .js subpage title to get the corresponding skin name
1913          *
1914          * @return string containing skin name from .css or .js subpage title
1915          */
1916         public function getSkinFromCssJsSubpage() {
1917                 $subpage = explode( '/', $this->mTextform );
1918                 $subpage = $subpage[ count( $subpage ) - 1 ];
1919                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1920         }
1921
1922         /**
1923          * Is this a .css subpage of a user page?
1924          *
1925          * @return \type{\bool}
1926          */
1927         public function isCssSubpage() {
1928                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1929         }
1930
1931         /**
1932          * Is this a .js subpage of a user page?
1933          *
1934          * @return \type{\bool}
1935          */
1936         public function isJsSubpage() {
1937                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1938         }
1939
1940         /**
1941          * Protect css subpages of user pages: can $wgUser edit
1942          * this page?
1943          *
1944          * @return \type{\bool}
1945          * @todo XXX: this might be better using restrictions
1946          */
1947         public function userCanEditCssSubpage() {
1948                 global $wgUser;
1949                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'editusercss' ) )
1950                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1951         }
1952
1953         /**
1954          * Protect js subpages of user pages: can $wgUser edit
1955          * this page?
1956          *
1957          * @return \type{\bool}
1958          * @todo XXX: this might be better using restrictions
1959          */
1960         public function userCanEditJsSubpage() {
1961                 global $wgUser;
1962                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'edituserjs' ) )
1963                        || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1964         }
1965
1966         /**
1967          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
1968          *
1969          * @return \type{\bool} If the page is subject to cascading restrictions.
1970          */
1971         public function isCascadeProtected() {
1972                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
1973                 return ( $sources > 0 );
1974         }
1975
1976         /**
1977          * Cascading protection: Get the source of any cascading restrictions on this page.
1978          *
1979          * @param $getPages \type{\bool} Whether or not to retrieve the actual pages
1980          *        that the restrictions have come from.
1981          * @return \type{\arrayof{mixed title array, restriction array}} Array of the Title
1982          *         objects of the pages from which cascading restrictions have come,
1983          *         false for none, or true if such restrictions exist, but $getPages was not set.
1984          *         The restriction array is an array of each type, each of which contains a
1985          *         array of unique groups.
1986          */
1987         public function getCascadeProtectionSources( $getPages = true ) {
1988                 $pagerestrictions = array();
1989
1990                 if ( isset( $this->mCascadeSources ) && $getPages ) {
1991                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
1992                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
1993                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
1994                 }
1995
1996                 wfProfileIn( __METHOD__ );
1997
1998                 $dbr = wfGetDB( DB_SLAVE );
1999
2000                 if ( $this->getNamespace() == NS_FILE ) {
2001                         $tables = array( 'imagelinks', 'page_restrictions' );
2002                         $where_clauses = array(
2003                                 'il_to' => $this->getDBkey(),
2004                                 'il_from=pr_page',
2005                                 'pr_cascade' => 1
2006                         );
2007                 } else {
2008                         $tables = array( 'templatelinks', 'page_restrictions' );
2009                         $where_clauses = array(
2010                                 'tl_namespace' => $this->getNamespace(),
2011                                 'tl_title' => $this->getDBkey(),
2012                                 'tl_from=pr_page',
2013                                 'pr_cascade' => 1
2014                         );
2015                 }
2016
2017                 if ( $getPages ) {
2018                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2019                                                    'pr_expiry', 'pr_type', 'pr_level' );
2020                         $where_clauses[] = 'page_id=pr_page';
2021                         $tables[] = 'page';
2022                 } else {
2023                         $cols = array( 'pr_expiry' );
2024                 }
2025
2026                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2027
2028                 $sources = $getPages ? array() : false;
2029                 $now = wfTimestampNow();
2030                 $purgeExpired = false;
2031
2032                 foreach ( $res as $row ) {
2033                         $expiry = Block::decodeExpiry( $row->pr_expiry );
2034                         if ( $expiry > $now ) {
2035                                 if ( $getPages ) {
2036                                         $page_id = $row->pr_page;
2037                                         $page_ns = $row->page_namespace;
2038                                         $page_title = $row->page_title;
2039                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2040                                         # Add groups needed for each restriction type if its not already there
2041                                         # Make sure this restriction type still exists
2042
2043                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2044                                                 $pagerestrictions[$row->pr_type] = array();
2045                                         }
2046
2047                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2048                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2049                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2050                                         }
2051                                 } else {
2052                                         $sources = true;
2053                                 }
2054                         } else {
2055                                 // Trigger lazy purge of expired restrictions from the db
2056                                 $purgeExpired = true;
2057                         }
2058                 }
2059                 if ( $purgeExpired ) {
2060                         Title::purgeExpiredRestrictions();
2061                 }
2062
2063                 wfProfileOut( __METHOD__ );
2064
2065                 if ( $getPages ) {
2066                         $this->mCascadeSources = $sources;
2067                         $this->mCascadingRestrictions = $pagerestrictions;
2068                 } else {
2069                         $this->mHasCascadingRestrictions = $sources;
2070                 }
2071
2072                 return array( $sources, $pagerestrictions );
2073         }
2074
2075         /**
2076          * Returns cascading restrictions for the current article
2077          *
2078          * @return Boolean
2079          */
2080         function areRestrictionsCascading() {
2081                 if ( !$this->mRestrictionsLoaded ) {
2082                         $this->loadRestrictions();
2083                 }
2084
2085                 return $this->mCascadeRestriction;
2086         }
2087
2088         /**
2089          * Loads a string into mRestrictions array
2090          *
2091          * @param $res \type{Resource} restrictions as an SQL result.
2092          * @param $oldFashionedRestrictions string comma-separated list of page
2093          *        restrictions from page table (pre 1.10)
2094          */
2095         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2096                 $rows = array();
2097
2098                 foreach ( $res as $row ) {
2099                         $rows[] = $row;
2100                 }
2101
2102                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2103         }
2104
2105         /**
2106          * Compiles list of active page restrictions from both page table (pre 1.10)
2107          * and page_restrictions table
2108          *
2109          * @param $rows array of db result objects
2110          * @param $oldFashionedRestrictions string comma-separated list of page
2111          *        restrictions from page table (pre 1.10)
2112          */
2113         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2114                 $dbr = wfGetDB( DB_SLAVE );
2115
2116                 $restrictionTypes = $this->getRestrictionTypes();
2117
2118                 foreach ( $restrictionTypes as $type ) {
2119                         $this->mRestrictions[$type] = array();
2120                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry( '' );
2121                 }
2122
2123                 $this->mCascadeRestriction = false;
2124
2125                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2126
2127                 if ( $oldFashionedRestrictions === null ) {
2128                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2129                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2130                 }
2131
2132                 if ( $oldFashionedRestrictions != '' ) {
2133
2134                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2135                                 $temp = explode( '=', trim( $restrict ) );
2136                                 if ( count( $temp ) == 1 ) {
2137                                         // old old format should be treated as edit/move restriction
2138                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2139                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2140                                 } else {
2141                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2142                                 }
2143                         }
2144
2145                         $this->mOldRestrictions = true;
2146
2147                 }
2148
2149                 if ( count( $rows ) ) {
2150                         # Current system - load second to make them override.
2151                         $now = wfTimestampNow();
2152                         $purgeExpired = false;
2153
2154                         foreach ( $rows as $row ) {
2155                                 # Cycle through all the restrictions.
2156
2157                                 // Don't take care of restrictions types that aren't allowed
2158
2159                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2160                                         continue;
2161
2162                                 // This code should be refactored, now that it's being used more generally,
2163                                 // But I don't really see any harm in leaving it in Block for now -werdna
2164                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
2165
2166                                 // Only apply the restrictions if they haven't expired!
2167                                 if ( !$expiry || $expiry > $now ) {
2168                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2169                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2170
2171                                         $this->mCascadeRestriction |= $row->pr_cascade;
2172                                 } else {
2173                                         // Trigger a lazy purge of expired restrictions
2174                                         $purgeExpired = true;
2175                                 }
2176                         }
2177
2178                         if ( $purgeExpired ) {
2179                                 Title::purgeExpiredRestrictions();
2180                         }
2181                 }
2182
2183                 $this->mRestrictionsLoaded = true;
2184         }
2185
2186         /**
2187          * Load restrictions from the page_restrictions table
2188          *
2189          * @param $oldFashionedRestrictions string comma-separated list of page
2190          *        restrictions from page table (pre 1.10)
2191          */
2192         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2193                 if ( !$this->mRestrictionsLoaded ) {
2194                         if ( $this->exists() ) {
2195                                 $dbr = wfGetDB( DB_SLAVE );
2196
2197                                 $res = $dbr->select( 'page_restrictions', '*',
2198                                         array( 'pr_page' => $this->getArticleId() ), __METHOD__ );
2199
2200                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2201                         } else {
2202                                 $title_protection = $this->getTitleProtection();
2203
2204                                 if ( $title_protection ) {
2205                                         $now = wfTimestampNow();
2206                                         $expiry = Block::decodeExpiry( $title_protection['pt_expiry'] );
2207
2208                                         if ( !$expiry || $expiry > $now ) {
2209                                                 // Apply the restrictions
2210                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2211                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2212                                         } else { // Get rid of the old restrictions
2213                                                 Title::purgeExpiredRestrictions();
2214                                         }
2215                                 } else {
2216                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry( '' );
2217                                 }
2218                                 $this->mRestrictionsLoaded = true;
2219                         }
2220                 }
2221         }
2222
2223         /**
2224          * Purge expired restrictions from the page_restrictions table
2225          */
2226         static function purgeExpiredRestrictions() {
2227                 $dbw = wfGetDB( DB_MASTER );
2228                 $dbw->delete(
2229                         'page_restrictions',
2230                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2231                         __METHOD__
2232                 );
2233
2234                 $dbw->delete(
2235                         'protected_titles',
2236                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2237                         __METHOD__
2238                 );
2239         }
2240
2241         /**
2242          * Accessor/initialisation for mRestrictions
2243          *
2244          * @param $action \type{\string} action that permission needs to be checked for
2245          * @return \type{\arrayof{\string}} the array of groups allowed to edit this article
2246          */
2247         public function getRestrictions( $action ) {
2248                 if ( !$this->mRestrictionsLoaded ) {
2249                         $this->loadRestrictions();
2250                 }
2251                 return isset( $this->mRestrictions[$action] )
2252                                 ? $this->mRestrictions[$action]
2253                                 : array();
2254         }
2255
2256         /**
2257          * Get the expiry time for the restriction against a given action
2258          *
2259          * @return 14-char timestamp, or 'infinity' if the page is protected forever
2260          *      or not protected at all, or false if the action is not recognised.
2261          */
2262         public function getRestrictionExpiry( $action ) {
2263                 if ( !$this->mRestrictionsLoaded ) {
2264                         $this->loadRestrictions();
2265                 }
2266                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2267         }
2268
2269         /**
2270          * Is there a version of this page in the deletion archive?
2271          *
2272          * @return \type{\int} the number of archived revisions
2273          */
2274         public function isDeleted() {
2275                 if ( $this->getNamespace() < 0 ) {
2276                         $n = 0;
2277                 } else {
2278                         $dbr = wfGetDB( DB_SLAVE );
2279                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2280                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2281                                 __METHOD__
2282                         );
2283                         if ( $this->getNamespace() == NS_FILE ) {
2284                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2285                                         array( 'fa_name' => $this->getDBkey() ),
2286                                         __METHOD__
2287                                 );
2288                         }
2289                 }
2290                 return (int)$n;
2291         }
2292
2293         /**
2294          * Is there a version of this page in the deletion archive?
2295          *
2296          * @return Boolean
2297          */
2298         public function isDeletedQuick() {
2299                 if ( $this->getNamespace() < 0 ) {
2300                         return false;
2301                 }
2302                 $dbr = wfGetDB( DB_SLAVE );
2303                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2304                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2305                         __METHOD__
2306                 );
2307                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2308                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2309                                 array( 'fa_name' => $this->getDBkey() ),
2310                                 __METHOD__
2311                         );
2312                 }
2313                 return $deleted;
2314         }
2315
2316         /**
2317          * Get the article ID for this Title from the link cache,
2318          * adding it if necessary
2319          *
2320          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select
2321          *  for update
2322          * @return \type{\int} the ID
2323          */
2324         public function getArticleID( $flags = 0 ) {
2325                 if ( $this->getNamespace() < 0 ) {
2326                         return $this->mArticleID = 0;
2327                 }
2328                 $linkCache = LinkCache::singleton();
2329                 if ( $flags & self::GAID_FOR_UPDATE ) {
2330                         $oldUpdate = $linkCache->forUpdate( true );
2331                         $linkCache->clearLink( $this );
2332                         $this->mArticleID = $linkCache->addLinkObj( $this );
2333                         $linkCache->forUpdate( $oldUpdate );
2334                 } else {
2335                         if ( -1 == $this->mArticleID ) {
2336                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2337                         }
2338                 }
2339                 return $this->mArticleID;
2340         }
2341
2342         /**
2343          * Is this an article that is a redirect page?
2344          * Uses link cache, adding it if necessary
2345          *
2346          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2347          * @return \type{\bool}
2348          */
2349         public function isRedirect( $flags = 0 ) {
2350                 if ( !is_null( $this->mRedirect ) ) {
2351                         return $this->mRedirect;
2352                 }
2353                 # Calling getArticleID() loads the field from cache as needed
2354                 if ( !$this->getArticleID( $flags ) ) {
2355                         return $this->mRedirect = false;
2356                 }
2357                 $linkCache = LinkCache::singleton();
2358                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2359
2360                 return $this->mRedirect;
2361         }
2362
2363         /**
2364          * What is the length of this page?
2365          * Uses link cache, adding it if necessary
2366          *
2367          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2368          * @return \type{\bool}
2369          */
2370         public function getLength( $flags = 0 ) {
2371                 if ( $this->mLength != -1 ) {
2372                         return $this->mLength;
2373                 }
2374                 # Calling getArticleID() loads the field from cache as needed
2375                 if ( !$this->getArticleID( $flags ) ) {
2376                         return $this->mLength = 0;
2377                 }
2378                 $linkCache = LinkCache::singleton();
2379                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2380
2381                 return $this->mLength;
2382         }
2383
2384         /**
2385          * What is the page_latest field for this page?
2386          *
2387          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2388          * @return \type{\int} or 0 if the page doesn't exist
2389          */
2390         public function getLatestRevID( $flags = 0 ) {
2391                 if ( $this->mLatestID !== false ) {
2392                         return intval( $this->mLatestID );
2393                 }
2394                 # Calling getArticleID() loads the field from cache as needed
2395                 if ( !$this->getArticleID( $flags ) ) {
2396                         return $this->mLatestID = 0;
2397                 }
2398                 $linkCache = LinkCache::singleton();
2399                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2400
2401                 return $this->mLatestID;
2402         }
2403
2404         /**
2405          * This clears some fields in this object, and clears any associated
2406          * keys in the "bad links" section of the link cache.
2407          *
2408          * - This is called from Article::insertNewArticle() to allow
2409          * loading of the new page_id. It's also called from
2410          * Article::doDeleteArticle()
2411          *
2412          * @param $newid \type{\int} the new Article ID
2413          */
2414         public function resetArticleID( $newid ) {
2415                 $linkCache = LinkCache::singleton();
2416                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2417
2418                 if ( $newid === false ) {
2419                         $this->mArticleID = -1;
2420                 } else {
2421                         $this->mArticleID = intval( $newid );
2422                 }
2423                 $this->mRestrictionsLoaded = false;
2424                 $this->mRestrictions = array();
2425                 $this->mRedirect = null;
2426                 $this->mLength = -1;
2427                 $this->mLatestID = false;
2428         }
2429
2430         /**
2431          * Updates page_touched for this page; called from LinksUpdate.php
2432          *
2433          * @return \type{\bool} true if the update succeded
2434          */
2435         public function invalidateCache() {
2436                 if ( wfReadOnly() ) {
2437                         return;
2438                 }
2439                 $dbw = wfGetDB( DB_MASTER );
2440                 $success = $dbw->update(
2441                         'page',
2442                         array( 'page_touched' => $dbw->timestamp() ),
2443                         $this->pageCond(),
2444                         __METHOD__
2445                 );
2446                 HTMLFileCache::clearFileCache( $this );
2447                 return $success;
2448         }
2449
2450         /**
2451          * Prefix some arbitrary text with the namespace or interwiki prefix
2452          * of this object
2453          *
2454          * @param $name \type{\string} the text
2455          * @return \type{\string} the prefixed text
2456          * @private
2457          */
2458         /* private */ function prefix( $name ) {
2459                 $p = '';
2460                 if ( $this->mInterwiki != '' ) {
2461                         $p = $this->mInterwiki . ':';
2462                 }
2463                 if ( 0 != $this->mNamespace ) {
2464                         $p .= $this->getNsText() . ':';
2465                 }
2466                 return $p . $name;
2467         }
2468
2469         /**
2470          * Returns a simple regex that will match on characters and sequences invalid in titles.
2471          * Note that this doesn't pick up many things that could be wrong with titles, but that
2472          * replacing this regex with something valid will make many titles valid.
2473          *
2474          * @return string regex string
2475          */
2476         static function getTitleInvalidRegex() {
2477                 static $rxTc = false;
2478                 if ( !$rxTc ) {
2479                         # Matching titles will be held as illegal.
2480                         $rxTc = '/' .
2481                                 # Any character not allowed is forbidden...
2482                                 '[^' . Title::legalChars() . ']' .
2483                                 # URL percent encoding sequences interfere with the ability
2484                                 # to round-trip titles -- you can't link to them consistently.
2485                                 '|%[0-9A-Fa-f]{2}' .
2486                                 # XML/HTML character references produce similar issues.
2487                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2488                                 '|&#[0-9]+;' .
2489                                 '|&#x[0-9A-Fa-f]+;' .
2490                                 '/S';
2491                 }
2492
2493                 return $rxTc;
2494         }
2495
2496         /**
2497          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2498          *
2499          * @param $text string containing title to capitalize
2500          * @param $ns int namespace index, defaults to NS_MAIN
2501          * @return String containing capitalized title
2502          */
2503         public static function capitalize( $text, $ns = NS_MAIN ) {
2504                 global $wgContLang;
2505
2506                 if ( MWNamespace::isCapitalized( $ns ) ) {
2507                         return $wgContLang->ucfirst( $text );
2508                 } else {
2509                         return $text;
2510                 }
2511         }
2512
2513         /**
2514          * Secure and split - main initialisation function for this object
2515          *
2516          * Assumes that mDbkeyform has been set, and is urldecoded
2517          * and uses underscores, but not otherwise munged.  This function
2518          * removes illegal characters, splits off the interwiki and
2519          * namespace prefixes, sets the other forms, and canonicalizes
2520          * everything.
2521          *
2522          * @return \type{\bool} true on success
2523          */
2524         private function secureAndSplit() {
2525                 global $wgContLang, $wgLocalInterwiki;
2526
2527                 # Initialisation
2528                 $rxTc = self::getTitleInvalidRegex();
2529
2530                 $this->mInterwiki = $this->mFragment = '';
2531                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2532
2533                 $dbkey = $this->mDbkeyform;
2534
2535                 # Strip Unicode bidi override characters.
2536                 # Sometimes they slip into cut-n-pasted page titles, where the
2537                 # override chars get included in list displays.
2538                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2539
2540                 # Clean up whitespace
2541                 # Note: use of the /u option on preg_replace here will cause
2542                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2543                 # conveniently disabling them.
2544                 #
2545                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2546                 $dbkey = trim( $dbkey, '_' );
2547
2548                 if ( $dbkey == '' ) {
2549                         return false;
2550                 }
2551
2552                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2553                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2554                         return false;
2555                 }
2556
2557                 $this->mDbkeyform = $dbkey;
2558
2559                 # Initial colon indicates main namespace rather than specified default
2560                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2561                 if ( ':' == $dbkey { 0 } ) {
2562                         $this->mNamespace = NS_MAIN;
2563                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2564                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2565                 }
2566
2567                 # Namespace or interwiki prefix
2568                 $firstPass = true;
2569                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2570                 do {
2571                         $m = array();
2572                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2573                                 $p = $m[1];
2574                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2575                                         # Ordinary namespace
2576                                         $dbkey = $m[2];
2577                                         $this->mNamespace = $ns;
2578                                         # For Talk:X pages, check if X has a "namespace" prefix
2579                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2580                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2581                                                         return false; # Disallow Talk:File:x type titles...
2582                                                 } else if ( Interwiki::isValidInterwiki( $x[1] ) ) {
2583                                                         return false; # Disallow Talk:Interwiki:x type titles...
2584                                                 }
2585                                         }
2586                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2587                                         if ( !$firstPass ) {
2588                                                 # Can't make a local interwiki link to an interwiki link.
2589                                                 # That's just crazy!
2590                                                 return false;
2591                                         }
2592
2593                                         # Interwiki link
2594                                         $dbkey = $m[2];
2595                                         $this->mInterwiki = $wgContLang->lc( $p );
2596
2597                                         # Redundant interwiki prefix to the local wiki
2598                                         if ( 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) ) {
2599                                                 if ( $dbkey == '' ) {
2600                                                         # Can't have an empty self-link
2601                                                         return false;
2602                                                 }
2603                                                 $this->mInterwiki = '';
2604                                                 $firstPass = false;
2605                                                 # Do another namespace split...
2606                                                 continue;
2607                                         }
2608
2609                                         # If there's an initial colon after the interwiki, that also
2610                                         # resets the default namespace
2611                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2612                                                 $this->mNamespace = NS_MAIN;
2613                                                 $dbkey = substr( $dbkey, 1 );
2614                                         }
2615                                 }
2616                                 # If there's no recognized interwiki or namespace,
2617                                 # then let the colon expression be part of the title.
2618                         }
2619                         break;
2620                 } while ( true );
2621
2622                 # We already know that some pages won't be in the database!
2623                 #
2624                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2625                         $this->mArticleID = 0;
2626                 }
2627                 $fragment = strstr( $dbkey, '#' );
2628                 if ( false !== $fragment ) {
2629                         $this->setFragment( preg_replace( '/^#_*/', '#', $fragment ) );
2630                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2631                         # remove whitespace again: prevents "Foo_bar_#"
2632                         # becoming "Foo_bar_"
2633                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2634                 }
2635
2636                 # Reject illegal characters.
2637                 #
2638                 if ( preg_match( $rxTc, $dbkey ) ) {
2639                         return false;
2640                 }
2641
2642                 /**
2643                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2644                  * reachable due to the way web browsers deal with 'relative' URLs.
2645                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2646                  */
2647                 if ( strpos( $dbkey, '.' ) !== false &&
2648                      ( $dbkey === '.' || $dbkey === '..' ||
2649                        strpos( $dbkey, './' ) === 0  ||
2650                        strpos( $dbkey, '../' ) === 0 ||
2651                        strpos( $dbkey, '/./' ) !== false ||
2652                        strpos( $dbkey, '/../' ) !== false  ||
2653                        substr( $dbkey, -2 ) == '/.' ||
2654                        substr( $dbkey, -3 ) == '/..' ) )
2655                 {
2656                         return false;
2657                 }
2658
2659                 /**
2660                  * Magic tilde sequences? Nu-uh!
2661                  */
2662                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2663                         return false;
2664                 }
2665
2666                 /**
2667                  * Limit the size of titles to 255 bytes.
2668                  * This is typically the size of the underlying database field.
2669                  * We make an exception for special pages, which don't need to be stored
2670                  * in the database, and may edge over 255 bytes due to subpage syntax
2671                  * for long titles, e.g. [[Special:Block/Long name]]
2672                  */
2673                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2674                   strlen( $dbkey ) > 512 )
2675                 {
2676                         return false;
2677                 }
2678
2679                 /**
2680                  * Normally, all wiki links are forced to have
2681                  * an initial capital letter so [[foo]] and [[Foo]]
2682                  * point to the same place.
2683                  *
2684                  * Don't force it for interwikis, since the other
2685                  * site might be case-sensitive.
2686                  */
2687                 $this->mUserCaseDBKey = $dbkey;
2688                 if ( $this->mInterwiki == '' ) {
2689                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2690                 }
2691
2692                 /**
2693                  * Can't make a link to a namespace alone...
2694                  * "empty" local links can only be self-links
2695                  * with a fragment identifier.
2696                  */
2697                 if ( $dbkey == '' &&
2698                         $this->mInterwiki == '' &&
2699                         $this->mNamespace != NS_MAIN ) {
2700                         return false;
2701                 }
2702                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2703                 // IP names are not allowed for accounts, and can only be referring to
2704                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2705                 // there are numerous ways to present the same IP. Having sp:contribs scan
2706                 // them all is silly and having some show the edits and others not is
2707                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2708                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK ) ?
2709                         IP::sanitizeIP( $dbkey ) : $dbkey;
2710                 // Any remaining initial :s are illegal.
2711                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2712                         return false;
2713                 }
2714
2715                 # Fill fields
2716                 $this->mDbkeyform = $dbkey;
2717                 $this->mUrlform = wfUrlencode( $dbkey );
2718
2719                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2720
2721                 return true;
2722         }
2723
2724         /**
2725          * Set the fragment for this title. Removes the first character from the
2726          * specified fragment before setting, so it assumes you're passing it with
2727          * an initial "#".
2728          *
2729          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2730          * Still in active use privately.
2731          *
2732          * @param $fragment \type{\string} text
2733          */
2734         public function setFragment( $fragment ) {
2735                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2736         }
2737
2738         /**
2739          * Get a Title object associated with the talk page of this article
2740          *
2741          * @return Title the object for the talk page
2742          */
2743         public function getTalkPage() {
2744                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2745         }
2746
2747         /**
2748          * Get a title object associated with the subject page of this
2749          * talk page
2750          *
2751          * @return Title the object for the subject page
2752          */
2753         public function getSubjectPage() {
2754                 // Is this the same title?
2755                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2756                 if ( $this->getNamespace() == $subjectNS ) {
2757                         return $this;
2758                 }
2759                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2760         }
2761
2762         /**
2763          * Get an array of Title objects linking to this Title
2764          * Also stores the IDs in the link cache.
2765          *
2766          * WARNING: do not use this function on arbitrary user-supplied titles!
2767          * On heavily-used templates it will max out the memory.
2768          *
2769          * @param $options Array: may be FOR UPDATE
2770          * @param $table String: table name
2771          * @param $prefix String: fields prefix
2772          * @return \type{\arrayof{Title}} the Title objects linking here
2773          */
2774         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2775                 $linkCache = LinkCache::singleton();
2776
2777                 if ( count( $options ) > 0 ) {
2778                         $db = wfGetDB( DB_MASTER );
2779                 } else {
2780                         $db = wfGetDB( DB_SLAVE );
2781                 }
2782
2783                 $res = $db->select(
2784                         array( 'page', $table ),
2785                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2786                         array(
2787                                 "{$prefix}_from=page_id",
2788                                 "{$prefix}_namespace" => $this->getNamespace(),
2789                                 "{$prefix}_title"     => $this->getDBkey() ),
2790                         __METHOD__,
2791                         $options
2792                 );
2793
2794                 $retVal = array();
2795                 if ( $db->numRows( $res ) ) {
2796                         foreach ( $res as $row ) {
2797                                 if ( $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title ) ) {
2798                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2799                                         $retVal[] = $titleObj;
2800                                 }
2801                         }
2802                 }
2803                 return $retVal;
2804         }
2805
2806         /**
2807          * Get an array of Title objects using this Title as a template
2808          * Also stores the IDs in the link cache.
2809          *
2810          * WARNING: do not use this function on arbitrary user-supplied titles!
2811          * On heavily-used templates it will max out the memory.
2812          *
2813          * @param $options Array: may be FOR UPDATE
2814          * @return \type{\arrayof{Title}} the Title objects linking here
2815          */
2816         public function getTemplateLinksTo( $options = array() ) {
2817                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2818         }
2819
2820         /**
2821          * Get an array of Title objects referring to non-existent articles linked from this page
2822          *
2823          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2824          * @return \type{\arrayof{Title}} the Title objects
2825          */
2826         public function getBrokenLinksFrom() {
2827                 if ( $this->getArticleId() == 0 ) {
2828                         # All links from article ID 0 are false positives
2829                         return array();
2830                 }
2831
2832                 $dbr = wfGetDB( DB_SLAVE );
2833                 $res = $dbr->select(
2834                         array( 'page', 'pagelinks' ),
2835                         array( 'pl_namespace', 'pl_title' ),
2836                         array(
2837                                 'pl_from' => $this->getArticleId(),
2838                                 'page_namespace IS NULL'
2839                         ),
2840                         __METHOD__, array(),
2841                         array(
2842                                 'page' => array(
2843                                         'LEFT JOIN',
2844                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2845                                 )
2846                         )
2847                 );
2848
2849                 $retVal = array();
2850                 foreach ( $res as $row ) {
2851                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2852                 }
2853                 return $retVal;
2854         }
2855
2856
2857         /**
2858          * Get a list of URLs to purge from the Squid cache when this
2859          * page changes
2860          *
2861          * @return \type{\arrayof{\string}} the URLs
2862          */
2863         public function getSquidURLs() {
2864                 global $wgContLang;
2865
2866                 $urls = array(
2867                         $this->getInternalURL(),
2868                         $this->getInternalURL( 'action=history' )
2869                 );
2870
2871                 // purge variant urls as well
2872                 if ( $wgContLang->hasVariants() ) {
2873                         $variants = $wgContLang->getVariants();
2874                         foreach ( $variants as $vCode ) {
2875                                 $urls[] = $this->getInternalURL( '', $vCode );
2876                         }
2877                 }
2878
2879                 return $urls;
2880         }
2881
2882         /**
2883          * Purge all applicable Squid URLs
2884          */
2885         public function purgeSquid() {
2886                 global $wgUseSquid;
2887                 if ( $wgUseSquid ) {
2888                         $urls = $this->getSquidURLs();
2889                         $u = new SquidUpdate( $urls );
2890                         $u->doUpdate();
2891                 }
2892         }
2893
2894         /**
2895          * Move this page without authentication
2896          *
2897          * @param $nt \type{Title} the new page Title
2898          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2899          */
2900         public function moveNoAuth( &$nt ) {
2901                 return $this->moveTo( $nt, false );
2902         }
2903
2904         /**
2905          * Check whether a given move operation would be valid.
2906          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2907          *
2908          * @param $nt \type{Title} the new title
2909          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2910          *  should be checked
2911          * @param $reason \type{\string} is the log summary of the move, used for spam checking
2912          * @return \type{\mixed} True on success, getUserPermissionsErrors()-like array on failure
2913          */
2914         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2915                 global $wgUser;
2916
2917                 $errors = array();
2918                 if ( !$nt ) {
2919                         // Normally we'd add this to $errors, but we'll get
2920                         // lots of syntax errors if $nt is not an object
2921                         return array( array( 'badtitletext' ) );
2922                 }
2923                 if ( $this->equals( $nt ) ) {
2924                         $errors[] = array( 'selfmove' );
2925                 }
2926                 if ( !$this->isMovable() ) {
2927                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2928                 }
2929                 if ( $nt->getInterwiki() != '' ) {
2930                         $errors[] = array( 'immobile-target-namespace-iw' );
2931                 }
2932                 if ( !$nt->isMovable() ) {
2933                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
2934                 }
2935
2936                 $oldid = $this->getArticleID();
2937                 $newid = $nt->getArticleID();
2938
2939                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2940                         $errors[] = array( 'articleexists' );
2941                 }
2942                 if ( ( $this->getDBkey() == '' ) ||
2943                          ( !$oldid ) ||
2944                      ( $nt->getDBkey() == '' ) ) {
2945                         $errors[] = array( 'badarticleerror' );
2946                 }
2947
2948                 // Image-specific checks
2949                 if ( $this->getNamespace() == NS_FILE ) {
2950                         if ( $nt->getNamespace() != NS_FILE ) {
2951                                 $errors[] = array( 'imagenocrossnamespace' );
2952                         }
2953                         $file = wfLocalFile( $this );
2954                         if ( $file->exists() ) {
2955                                 if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
2956                                         $errors[] = array( 'imageinvalidfilename' );
2957                                 }
2958                                 if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
2959                                         $errors[] = array( 'imagetypemismatch' );
2960                                 }
2961                         }
2962                         $destfile = wfLocalFile( $nt );
2963                         if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destfile->exists() && wfFindFile( $nt ) ) {
2964                                 $errors[] = array( 'file-exists-sharedrepo' );
2965                         }
2966                 }
2967
2968                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
2969                         $errors[] = array( 'nonfile-cannot-move-to-file' );
2970                 }
2971
2972                 if ( $auth ) {
2973                         $errors = wfMergeErrorArrays( $errors,
2974                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
2975                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
2976                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
2977                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
2978                 }
2979
2980                 $match = EditPage::matchSummarySpamRegex( $reason );
2981                 if ( $match !== false ) {
2982                         // This is kind of lame, won't display nice
2983                         $errors[] = array( 'spamprotectiontext' );
2984                 }
2985
2986                 $err = null;
2987                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
2988                         $errors[] = array( 'hookaborted', $err );
2989                 }
2990
2991                 # The move is allowed only if (1) the target doesn't exist, or
2992                 # (2) the target is a redirect to the source, and has no history
2993                 # (so we can undo bad moves right after they're done).
2994
2995                 if ( 0 != $newid ) { # Target exists; check for validity
2996                         if ( !$this->isValidMoveTarget( $nt ) ) {
2997                                 $errors[] = array( 'articleexists' );
2998                         }
2999                 } else {
3000                         $tp = $nt->getTitleProtection();
3001                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3002                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3003                                 $errors[] = array( 'cantmove-titleprotected' );
3004                         }
3005                 }
3006                 if ( empty( $errors ) ) {
3007                         return true;
3008                 }
3009                 return $errors;
3010         }
3011
3012         /**
3013          * Move a title to a new location
3014          *
3015          * @param $nt \type{Title} the new title
3016          * @param $auth \type{\bool} indicates whether $wgUser's permissions
3017          *  should be checked
3018          * @param $reason \type{\string} The reason for the move
3019          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title.
3020          *  Ignored if the user doesn't have the suppressredirect right.
3021          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
3022          */
3023         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3024                 global $wgContLang;
3025
3026                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3027                 if ( is_array( $err ) ) {
3028                         return $err;
3029                 }
3030
3031                 // If it is a file, move it first. It is done before all other moving stuff is done because it's hard to revert
3032                 $dbw = wfGetDB( DB_MASTER );
3033                 if ( $this->getNamespace() == NS_FILE ) {
3034                         $file = wfLocalFile( $this );
3035                         if ( $file->exists() ) {
3036                                 $status = $file->move( $nt );
3037                                 if ( !$status->isOk() ) {
3038                                         return $status->getErrorsArray();
3039                                 }
3040                         }
3041                 }
3042
3043                 $pageid = $this->getArticleID();
3044                 $protected = $this->isProtected();
3045                 if ( $nt->exists() ) {
3046                         $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
3047                         $pageCountChange = ( $createRedirect ? 0 : -1 );
3048                 } else { # Target didn't exist, do normal move.
3049                         $err = $this->moveToNewTitle( $nt, $reason, $createRedirect );
3050                         $pageCountChange = ( $createRedirect ? 1 : 0 );
3051                 }
3052
3053                 if ( is_array( $err ) ) {
3054                         return $err;
3055                 }
3056                 $redirid = $this->getArticleID();
3057
3058                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3059                 // cl_timestamp, which may disturb time-based lists on some sites.
3060                 $prefix = $dbw->selectField(
3061                         'categorylinks',
3062                         'cl_sortkey_prefix',
3063                         array( 'cl_from' => $pageid ),
3064                         __METHOD__
3065                 );
3066                 $dbw->update( 'categorylinks',
3067                         array(
3068                                 'cl_sortkey' => $wgContLang->convertToSortkey( $nt->getCategorySortkey( $prefix ) ),
3069                                 'cl_timestamp=cl_timestamp' ),
3070                         array( 'cl_from' => $pageid ),
3071                         __METHOD__ );
3072
3073                 if ( $protected ) {
3074                         # Protect the redirect title as the title used to be...
3075                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3076                                 array(
3077                                         'pr_page'    => $redirid,
3078                                         'pr_type'    => 'pr_type',
3079                                         'pr_level'   => 'pr_level',
3080                                         'pr_cascade' => 'pr_cascade',
3081                                         'pr_user'    => 'pr_user',
3082                                         'pr_expiry'  => 'pr_expiry'
3083                                 ),
3084                                 array( 'pr_page' => $pageid ),
3085                                 __METHOD__,
3086                                 array( 'IGNORE' )
3087                         );
3088                         # Update the protection log
3089                         $log = new LogPage( 'protect' );
3090                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3091                         if ( $reason ) {
3092                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3093                         }
3094                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) ); // FIXME: $params?
3095                 }
3096
3097                 # Update watchlists
3098                 $oldnamespace = $this->getNamespace() & ~1;
3099                 $newnamespace = $nt->getNamespace() & ~1;
3100                 $oldtitle = $this->getDBkey();
3101                 $newtitle = $nt->getDBkey();
3102
3103                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3104                         WatchedItem::duplicateEntries( $this, $nt );
3105                 }
3106
3107                 # Update search engine
3108                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3109                 $u->doUpdate();
3110                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3111                 $u->doUpdate();
3112
3113                 # Update site_stats
3114                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3115                         # No longer a content page
3116                         # Not viewed, edited, removing
3117                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3118                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3119                         # Now a content page
3120                         # Not viewed, edited, adding
3121                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3122                 } elseif ( $pageCountChange ) {
3123                         # Redirect added
3124                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3125                 } else {
3126                         # Nothing special
3127                         $u = false;
3128                 }
3129                 if ( $u ) {
3130                         $u->doUpdate();
3131                 }
3132                 # Update message cache for interface messages
3133                 global $wgMessageCache;
3134                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3135                         # @bug 17860: old article can be deleted, if this the case,
3136                         # delete it from message cache
3137                         if ( $this->getArticleID() === 0 ) {
3138                                 $wgMessageCache->replace( $this->getDBkey(), false );
3139                         } else {
3140                                 $oldarticle = new Article( $this );
3141                                 $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
3142                         }
3143                 }
3144                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3145                         $newarticle = new Article( $nt );
3146                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
3147                 }
3148
3149                 global $wgUser;
3150                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3151                 return true;
3152         }
3153
3154         /**
3155          * Move page to a title which is at present a redirect to the
3156          * source page
3157          *
3158          * @param $nt \type{Title} the page to move to, which should currently
3159          *  be a redirect
3160          * @param $reason \type{\string} The reason for the move
3161          * @param $createRedirect \type{\bool} Whether to leave a redirect at the old title.
3162          *  Ignored if the user doesn't have the suppressredirect right
3163          */
3164         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
3165                 global $wgUseSquid, $wgUser, $wgContLang;
3166
3167                 $comment = wfMsgForContent( '1movedto2_redir', $this->getPrefixedText(), $nt->getPrefixedText() );
3168
3169                 if ( $reason ) {
3170                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3171                 }
3172                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3173                 $comment = $wgContLang->truncate( $comment, 250 );
3174
3175                 $now = wfTimestampNow();
3176                 $newid = $nt->getArticleID();
3177                 $oldid = $this->getArticleID();
3178                 $latest = $this->getLatestRevID();
3179
3180                 $dbw = wfGetDB( DB_MASTER );
3181
3182                 $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3183                 $newns = $nt->getNamespace();
3184                 $newdbk = $nt->getDBkey();
3185
3186                 # Delete the old redirect. We don't save it to history since
3187                 # by definition if we've got here it's rather uninteresting.
3188                 # We have to remove it so that the next step doesn't trigger
3189                 # a conflict on the unique namespace+title index...
3190                 $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3191                 if ( !$dbw->cascadingDeletes() ) {
3192                         $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3193                         global $wgUseTrackbacks;
3194                         if ( $wgUseTrackbacks ) {
3195                                 $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3196                         }
3197                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3198                         $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3199                         $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3200                         $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3201                         $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3202                         $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3203                         $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3204                 }
3205                 // If the redirect was recently created, it may have an entry in recentchanges still
3206                 $dbw->delete( 'recentchanges',
3207                         array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3208                         __METHOD__
3209                 );
3210
3211                 # Save a null revision in the page's history notifying of the move
3212                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3213                 $nullRevId = $nullRevision->insertOn( $dbw );
3214
3215                 $article = new Article( $this );
3216                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3217
3218                 # Change the name of the target page:
3219                 $dbw->update( 'page',
3220                         /* SET */ array(
3221                                 'page_touched'   => $dbw->timestamp( $now ),
3222                                 'page_namespace' => $nt->getNamespace(),
3223                                 'page_title'     => $nt->getDBkey(),
3224                                 'page_latest'    => $nullRevId,
3225                         ),
3226                         /* WHERE */ array( 'page_id' => $oldid ),
3227                         __METHOD__
3228                 );
3229                 $nt->resetArticleID( $oldid );
3230
3231                 # Recreate the redirect, this time in the other direction.
3232                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3233                         $mwRedir = MagicWord::get( 'redirect' );
3234                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3235                         $redirectArticle = new Article( $this );
3236                         $newid = $redirectArticle->insertOn( $dbw );
3237                         $redirectRevision = new Revision( array(
3238                                 'page'    => $newid,
3239                                 'comment' => $comment,
3240                                 'text'    => $redirectText ) );
3241                         $redirectRevision->insertOn( $dbw );
3242                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3243
3244                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3245
3246                         # Now, we record the link from the redirect to the new title.
3247                         # It should have no other outgoing links...
3248                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3249                         $dbw->insert( 'pagelinks',
3250                                 array(
3251                                         'pl_from'      => $newid,
3252                                         'pl_namespace' => $nt->getNamespace(),
3253                                         'pl_title'     => $nt->getDBkey() ),
3254                                 __METHOD__ );
3255                         $redirectSuppressed = false;
3256                 } else {
3257                         $this->resetArticleID( 0 );
3258                         $redirectSuppressed = true;
3259                 }
3260
3261                 # Log the move
3262                 $log = new LogPage( 'move' );
3263                 $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3264
3265                 # Purge squid
3266                 if ( $wgUseSquid ) {
3267                         $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
3268                         $u = new SquidUpdate( $urls );
3269                         $u->doUpdate();
3270                 }
3271
3272         }
3273
3274         /**
3275          * Move page to non-existing title.
3276          *
3277          * @param $nt \type{Title} the new Title
3278          * @param $reason \type{\string} The reason for the move
3279          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title
3280          *  Ignored if the user doesn't have the suppressredirect right
3281          */
3282         private function moveToNewTitle( &$nt, $reason = '', $createRedirect = true ) {
3283                 global $wgUser, $wgContLang;
3284
3285                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3286                 if ( $reason ) {
3287                         $comment .= wfMsgExt( 'colon-separator',
3288                                 array( 'escapenoentities', 'content' ) );
3289                         $comment .= $reason;
3290                 }
3291                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3292                 $comment = $wgContLang->truncate( $comment, 250 );
3293
3294                 $newid = $nt->getArticleID();
3295                 $oldid = $this->getArticleID();
3296                 $latest = $this->getLatestRevId();
3297
3298                 $dbw = wfGetDB( DB_MASTER );
3299                 $now = $dbw->timestamp();
3300
3301                 # Save a null revision in the page's history notifying of the move
3302                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3303                 if ( !is_object( $nullRevision ) ) {
3304                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3305                 }
3306                 $nullRevId = $nullRevision->insertOn( $dbw );
3307
3308                 $article = new Article( $this );
3309                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3310
3311                 # Rename page entry
3312                 $dbw->update( 'page',
3313                         /* SET */ array(
3314                                 'page_touched'   => $now,
3315                                 'page_namespace' => $nt->getNamespace(),
3316                                 'page_title'     => $nt->getDBkey(),
3317                                 'page_latest'    => $nullRevId,
3318                         ),
3319                         /* WHERE */ array( 'page_id' => $oldid ),
3320                         __METHOD__
3321                 );
3322                 $nt->resetArticleID( $oldid );
3323
3324                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3325                         # Insert redirect
3326                         $mwRedir = MagicWord::get( 'redirect' );
3327                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3328                         $redirectArticle = new Article( $this );
3329                         $newid = $redirectArticle->insertOn( $dbw );
3330                         $redirectRevision = new Revision( array(
3331                                 'page'    => $newid,
3332                                 'comment' => $comment,
3333                                 'text'    => $redirectText ) );
3334                         $redirectRevision->insertOn( $dbw );
3335                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3336
3337                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3338
3339                         # Record the just-created redirect's linking to the page
3340                         $dbw->insert( 'pagelinks',
3341                                 array(
3342                                         'pl_from'      => $newid,
3343                                         'pl_namespace' => $nt->getNamespace(),
3344                                         'pl_title'     => $nt->getDBkey() ),
3345                                 __METHOD__ );
3346                         $redirectSuppressed = false;
3347                 } else {
3348                         $this->resetArticleID( 0 );
3349                         $redirectSuppressed = true;
3350                 }
3351
3352                 # Log the move
3353                 $log = new LogPage( 'move' );
3354                 $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3355
3356                 # Purge caches as per article creation
3357                 Article::onArticleCreate( $nt );
3358
3359                 # Purge old title from squid
3360                 # The new title, and links to the new title, are purged in Article::onArticleCreate()
3361                 $this->purgeSquid();
3362         }
3363
3364         /**
3365          * Move this page's subpages to be subpages of $nt
3366          *
3367          * @param $nt Title Move target
3368          * @param $auth bool Whether $wgUser's permissions should be checked
3369          * @param $reason string The reason for the move
3370          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
3371          *  Ignored if the user doesn't have the 'suppressredirect' right
3372          * @return mixed array with old page titles as keys, and strings (new page titles) or
3373          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
3374          */
3375         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3376                 global $wgMaximumMovedPages;
3377                 // Check permissions
3378                 if ( !$this->userCan( 'move-subpages' ) ) {
3379                         return array( 'cant-move-subpages' );
3380                 }
3381                 // Do the source and target namespaces support subpages?
3382                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3383                         return array( 'namespace-nosubpages',
3384                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3385                 }
3386                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3387                         return array( 'namespace-nosubpages',
3388                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3389                 }
3390
3391                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3392                 $retval = array();
3393                 $count = 0;
3394                 foreach ( $subpages as $oldSubpage ) {
3395                         $count++;
3396                         if ( $count > $wgMaximumMovedPages ) {
3397                                 $retval[$oldSubpage->getPrefixedTitle()] =
3398                                                 array( 'movepage-max-pages',
3399                                                         $wgMaximumMovedPages );
3400                                 break;
3401                         }
3402
3403                         // We don't know whether this function was called before
3404                         // or after moving the root page, so check both
3405                         // $this and $nt
3406                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3407                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3408                         {
3409                                 // When moving a page to a subpage of itself,
3410                                 // don't move it twice
3411                                 continue;
3412                         }
3413                         $newPageName = preg_replace(
3414                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3415                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3416                                         $oldSubpage->getDBkey() );
3417                         if ( $oldSubpage->isTalkPage() ) {
3418                                 $newNs = $nt->getTalkPage()->getNamespace();
3419                         } else {
3420                                 $newNs = $nt->getSubjectPage()->getNamespace();
3421                         }
3422                         # Bug 14385: we need makeTitleSafe because the new page names may
3423                         # be longer than 255 characters.
3424                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3425
3426                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3427                         if ( $success === true ) {
3428                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3429                         } else {
3430                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3431                         }
3432                 }
3433                 return $retval;
3434         }
3435
3436         /**
3437          * Checks if this page is just a one-rev redirect.
3438          * Adds lock, so don't use just for light purposes.
3439          *
3440          * @return \type{\bool}
3441          */
3442         public function isSingleRevRedirect() {
3443                 $dbw = wfGetDB( DB_MASTER );
3444                 # Is it a redirect?
3445                 $row = $dbw->selectRow( 'page',
3446                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3447                         $this->pageCond(),
3448                         __METHOD__,
3449                         array( 'FOR UPDATE' )
3450                 );
3451                 # Cache some fields we may want
3452                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3453                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3454                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3455                 if ( !$this->mRedirect ) {
3456                         return false;
3457                 }
3458                 # Does the article have a history?
3459                 $row = $dbw->selectField( array( 'page', 'revision' ),
3460                         'rev_id',
3461                         array( 'page_namespace' => $this->getNamespace(),
3462                                 'page_title' => $this->getDBkey(),
3463                                 'page_id=rev_page',
3464                                 'page_latest != rev_id'
3465                         ),
3466                         __METHOD__,
3467                         array( 'FOR UPDATE' )
3468                 );
3469                 # Return true if there was no history
3470                 return ( $row === false );
3471         }
3472
3473         /**
3474          * Checks if $this can be moved to a given Title
3475          * - Selects for update, so don't call it unless you mean business
3476          *
3477          * @param $nt \type{Title} the new title to check
3478          * @return \type{\bool} TRUE or FALSE
3479          */
3480         public function isValidMoveTarget( $nt ) {
3481                 # Is it an existing file?
3482                 if ( $nt->getNamespace() == NS_FILE ) {
3483                         $file = wfLocalFile( $nt );
3484                         if ( $file->exists() ) {
3485                                 wfDebug( __METHOD__ . ": file exists\n" );
3486                                 return false;
3487                         }
3488                 }
3489                 # Is it a redirect with no history?
3490                 if ( !$nt->isSingleRevRedirect() ) {
3491                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3492                         return false;
3493                 }
3494                 # Get the article text
3495                 $rev = Revision::newFromTitle( $nt );
3496                 $text = $rev->getText();
3497                 # Does the redirect point to the source?
3498                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3499                 $m = array();
3500                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3501                         $redirTitle = Title::newFromText( $m[1] );
3502                         if ( !is_object( $redirTitle ) ||
3503                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3504                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3505                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3506                                 return false;
3507                         }
3508                 } else {
3509                         # Fail safe
3510                         wfDebug( __METHOD__ . ": failsafe\n" );
3511                         return false;
3512                 }
3513                 return true;
3514         }
3515
3516         /**
3517          * Can this title be added to a user's watchlist?
3518          *
3519          * @return \type{\bool} TRUE or FALSE
3520          */
3521         public function isWatchable() {
3522                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3523         }
3524
3525         /**
3526          * Get categories to which this Title belongs and return an array of
3527          * categories' names.
3528          *
3529          * @return \type{\array} array an array of parents in the form:
3530          *      $parent => $currentarticle
3531          */
3532         public function getParentCategories() {
3533                 global $wgContLang;
3534
3535                 $titlekey = $this->getArticleId();
3536                 $dbr = wfGetDB( DB_SLAVE );
3537                 $categorylinks = $dbr->tableName( 'categorylinks' );
3538
3539                 # NEW SQL
3540                 $sql = "SELECT * FROM $categorylinks"
3541                      . " WHERE cl_from='$titlekey'"
3542                          . " AND cl_from <> '0'"
3543                          . " ORDER BY cl_sortkey";
3544
3545                 $res = $dbr->query( $sql );
3546                 $data = array();
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 \type{\array} an array with the children in the keys, to check for circular refs
3561          * @return \type{\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         /**
3586          * Get an associative array for selecting this title from
3587          * the "page" table
3588          *
3589          * @return \type{\array} Selection array
3590          */
3591         public function pageCond() {
3592                 if ( $this->mArticleID > 0 ) {
3593                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3594                         return array( 'page_id' => $this->mArticleID );
3595                 } else {
3596                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3597                 }
3598         }
3599
3600         /**
3601          * Get the revision ID of the previous revision
3602          *
3603          * @param $revId \type{\int} Revision ID. Get the revision that was before this one.
3604          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3605          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3606          */
3607         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3608                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3609                 return $db->selectField( 'revision', 'rev_id',
3610                         array(
3611                                 'rev_page' => $this->getArticleId( $flags ),
3612                                 'rev_id < ' . intval( $revId )
3613                         ),
3614                         __METHOD__,
3615                         array( 'ORDER BY' => 'rev_id DESC' )
3616                 );
3617         }
3618
3619         /**
3620          * Get the revision ID of the next revision
3621          *
3622          * @param $revId \type{\int} Revision ID. Get the revision that was after this one.
3623          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3624          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3625          */
3626         public function getNextRevisionID( $revId, $flags = 0 ) {
3627                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3628                 return $db->selectField( 'revision', 'rev_id',
3629                         array(
3630                                 'rev_page' => $this->getArticleId( $flags ),
3631                                 'rev_id > ' . intval( $revId )
3632                         ),
3633                         __METHOD__,
3634                         array( 'ORDER BY' => 'rev_id' )
3635                 );
3636         }
3637
3638         /**
3639          * Get the first revision of the page
3640          *
3641          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3642          * @return Revision (or NULL if page doesn't exist)
3643          */
3644         public function getFirstRevision( $flags = 0 ) {
3645                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3646                 $pageId = $this->getArticleId( $flags );
3647                 if ( !$pageId ) {
3648                         return null;
3649                 }
3650                 $row = $db->selectRow( 'revision', '*',
3651                         array( 'rev_page' => $pageId ),
3652                         __METHOD__,
3653                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3654                 );
3655                 if ( !$row ) {
3656                         return null;
3657                 } else {
3658                         return new Revision( $row );
3659                 }
3660         }
3661
3662         /**
3663          * Check if this is a new page
3664          *
3665          * @return bool
3666          */
3667         public function isNewPage() {
3668                 $dbr = wfGetDB( DB_SLAVE );
3669                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3670         }
3671
3672         /**
3673          * Get the oldest revision timestamp of this page
3674          *
3675          * @return String: MW timestamp
3676          */
3677         public function getEarliestRevTime() {
3678                 $dbr = wfGetDB( DB_SLAVE );
3679                 if ( $this->exists() ) {
3680                         $min = $dbr->selectField( 'revision',
3681                                 'MIN(rev_timestamp)',
3682                                 array( 'rev_page' => $this->getArticleId() ),
3683                                 __METHOD__ );
3684                         return wfTimestampOrNull( TS_MW, $min );
3685                 }
3686                 return null;
3687         }
3688
3689         /**
3690          * Get the number of revisions between the given revision IDs.
3691          * Used for diffs and other things that really need it.
3692          *
3693          * @param $old \type{\int} Revision ID.
3694          * @param $new \type{\int} Revision ID.
3695          * @return \type{\int} Number of revisions between these IDs.
3696          */
3697         public function countRevisionsBetween( $old, $new ) {
3698                 $dbr = wfGetDB( DB_SLAVE );
3699                 return (int)$dbr->selectField( 'revision', 'count(*)',
3700                         'rev_page = ' . intval( $this->getArticleId() ) .
3701                         ' AND rev_id > ' . intval( $old ) .
3702                         ' AND rev_id < ' . intval( $new ),
3703                         __METHOD__
3704                 );
3705         }
3706
3707         /**
3708          * Compare with another title.
3709          *
3710          * @param $title \type{Title}
3711          * @return \type{\bool} TRUE or FALSE
3712          */
3713         public function equals( Title $title ) {
3714                 // Note: === is necessary for proper matching of number-like titles.
3715                 return $this->getInterwiki() === $title->getInterwiki()
3716                         && $this->getNamespace() == $title->getNamespace()
3717                         && $this->getDBkey() === $title->getDBkey();
3718         }
3719
3720         /**
3721          * Callback for usort() to do title sorts by (namespace, title)
3722          *
3723          * @return Integer: result of string comparison, or namespace comparison
3724          */
3725         public static function compare( $a, $b ) {
3726                 if ( $a->getNamespace() == $b->getNamespace() ) {
3727                         return strcmp( $a->getText(), $b->getText() );
3728                 } else {
3729                         return $a->getNamespace() - $b->getNamespace();
3730                 }
3731         }
3732
3733         /**
3734          * Return a string representation of this title
3735          *
3736          * @return \type{\string} String representation of this title
3737          */
3738         public function __toString() {
3739                 return $this->getPrefixedText();
3740         }
3741
3742         /**
3743          * Check if page exists.  For historical reasons, this function simply
3744          * checks for the existence of the title in the page table, and will
3745          * thus return false for interwiki links, special pages and the like.
3746          * If you want to know if a title can be meaningfully viewed, you should
3747          * probably call the isKnown() method instead.
3748          *
3749          * @return \type{\bool}
3750          */
3751         public function exists() {
3752                 return $this->getArticleId() != 0;
3753         }
3754
3755         /**
3756          * Should links to this title be shown as potentially viewable (i.e. as
3757          * "bluelinks"), even if there's no record by this title in the page
3758          * table?
3759          *
3760          * This function is semi-deprecated for public use, as well as somewhat
3761          * misleadingly named.  You probably just want to call isKnown(), which
3762          * calls this function internally.
3763          *
3764          * (ISSUE: Most of these checks are cheap, but the file existence check
3765          * can potentially be quite expensive.  Including it here fixes a lot of
3766          * existing code, but we might want to add an optional parameter to skip
3767          * it and any other expensive checks.)
3768          *
3769          * @return \type{\bool}
3770          */
3771         public function isAlwaysKnown() {
3772                 if ( $this->mInterwiki != '' ) {
3773                         return true;  // any interwiki link might be viewable, for all we know
3774                 }
3775                 switch( $this->mNamespace ) {
3776                         case NS_MEDIA:
3777                         case NS_FILE:
3778                                 return (bool)wfFindFile( $this );  // file exists, possibly in a foreign repo
3779                         case NS_SPECIAL:
3780                                 return SpecialPage::exists( $this->getDBkey() );  // valid special page
3781                         case NS_MAIN:
3782                                 return $this->mDbkeyform == '';  // selflink, possibly with fragment
3783                         case NS_MEDIAWIKI:
3784                                 // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3785                                 // the full l10n of that language to be loaded. That takes much memory and
3786                                 // isn't needed. So we strip the language part away.
3787                                 list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3788                                 return (bool)wfMsgWeirdKey( $basename );  // known system message
3789                         default:
3790                                 return false;
3791                 }
3792         }
3793
3794         /**
3795          * Does this title refer to a page that can (or might) be meaningfully
3796          * viewed?  In particular, this function may be used to determine if
3797          * links to the title should be rendered as "bluelinks" (as opposed to
3798          * "redlinks" to non-existent pages).
3799          *
3800          * @return \type{\bool}
3801          */
3802         public function isKnown() {
3803                 return $this->isAlwaysKnown() || $this->exists();
3804         }
3805
3806         /**
3807          * Does this page have source text?
3808          *
3809          * @return Boolean
3810          */
3811         public function hasSourceText() {
3812                 if ( $this->exists() ) {
3813                         return true;
3814                 }
3815
3816                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3817                         // If the page doesn't exist but is a known system message, default
3818                         // message content will be displayed, same for language subpages
3819                         // Also, if the page is form Mediawiki:message/lang, calling wfMsgWeirdKey
3820                         // causes the full l10n of that language to be loaded. That takes much
3821                         // memory and isn't needed. So we strip the language part away.
3822                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3823                         return (bool)wfMsgWeirdKey( $basename );
3824                 }
3825
3826                 return false;
3827         }
3828
3829         /**
3830          * Is this in a namespace that allows actual pages?
3831          *
3832          * @return \type{\bool}
3833          * @internal note -- uses hardcoded namespace index instead of constants
3834          */
3835         public function canExist() {
3836                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3837         }
3838
3839         /**
3840          * Update page_touched timestamps and send squid purge messages for
3841          * pages linking to this title. May be sent to the job queue depending
3842          * on the number of links. Typically called on create and delete.
3843          */
3844         public function touchLinks() {
3845                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3846                 $u->doUpdate();
3847
3848                 if ( $this->getNamespace() == NS_CATEGORY ) {
3849                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3850                         $u->doUpdate();
3851                 }
3852         }
3853
3854         /**
3855          * Get the last touched timestamp
3856          *
3857          * @param $db DatabaseBase: optional db
3858          * @return \type{\string} Last touched timestamp
3859          */
3860         public function getTouched( $db = null ) {
3861                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3862                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3863                 return $touched;
3864         }
3865
3866         /**
3867          * Get the timestamp when this page was updated since the user last saw it.
3868          *
3869          * @param $user User
3870          * @return Mixed: string/null
3871          */
3872         public function getNotificationTimestamp( $user = null ) {
3873                 global $wgUser, $wgShowUpdatedMarker;
3874                 // Assume current user if none given
3875                 if ( !$user ) {
3876                         $user = $wgUser;
3877                 }
3878                 // Check cache first
3879                 $uid = $user->getId();
3880                 if ( isset( $this->mNotificationTimestamp[$uid] ) ) {
3881                         return $this->mNotificationTimestamp[$uid];
3882                 }
3883                 if ( !$uid || !$wgShowUpdatedMarker ) {
3884                         return $this->mNotificationTimestamp[$uid] = false;
3885                 }
3886                 // Don't cache too much!
3887                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3888                         $this->mNotificationTimestamp = array();
3889                 }
3890                 $dbr = wfGetDB( DB_SLAVE );
3891                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3892                         'wl_notificationtimestamp',
3893                         array( 'wl_namespace' => $this->getNamespace(),
3894                                 'wl_title' => $this->getDBkey(),
3895                                 'wl_user' => $user->getId()
3896                         ),
3897                         __METHOD__
3898                 );
3899                 return $this->mNotificationTimestamp[$uid];
3900         }
3901
3902         /**
3903          * Get the trackback URL for this page
3904          *
3905          * @return \type{\string} Trackback URL
3906          */
3907         public function trackbackURL() {
3908                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3909
3910                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3911                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3912         }
3913
3914         /**
3915          * Get the trackback RDF for this page
3916          *
3917          * @return \type{\string} Trackback RDF
3918          */
3919         public function trackbackRDF() {
3920                 $url = htmlspecialchars( $this->getFullURL() );
3921                 $title = htmlspecialchars( $this->getText() );
3922                 $tburl = $this->trackbackURL();
3923
3924                 // Autodiscovery RDF is placed in comments so HTML validator
3925                 // won't barf. This is a rather icky workaround, but seems
3926                 // frequently used by this kind of RDF thingy.
3927                 //
3928                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3929                 return "<!--
3930 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3931          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3932          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3933 <rdf:Description
3934    rdf:about=\"$url\"
3935    dc:identifier=\"$url\"
3936    dc:title=\"$title\"
3937    trackback:ping=\"$tburl\" />
3938 </rdf:RDF>
3939 -->";
3940         }
3941
3942         /**
3943          * Generate strings used for xml 'id' names in monobook tabs
3944          *
3945          * @param $prepend string defaults to 'nstab-'
3946          * @return \type{\string} XML 'id' name
3947          */
3948         public function getNamespaceKey( $prepend = 'nstab-' ) {
3949                 global $wgContLang;
3950                 // Gets the subject namespace if this title
3951                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
3952                 // Checks if cononical namespace name exists for namespace
3953                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
3954                         // Uses canonical namespace name
3955                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
3956                 } else {
3957                         // Uses text of namespace
3958                         $namespaceKey = $this->getSubjectNsText();
3959                 }
3960                 // Makes namespace key lowercase
3961                 $namespaceKey = $wgContLang->lc( $namespaceKey );
3962                 // Uses main
3963                 if ( $namespaceKey == '' ) {
3964                         $namespaceKey = 'main';
3965                 }
3966                 // Changes file to image for backwards compatibility
3967                 if ( $namespaceKey == 'file' ) {
3968                         $namespaceKey = 'image';
3969                 }
3970                 return $prepend . $namespaceKey;
3971         }
3972
3973         /**
3974          * Returns true if this is a special page.
3975          *
3976          * @return boolean
3977          */
3978         public function isSpecialPage() {
3979                 return $this->getNamespace() == NS_SPECIAL;
3980         }
3981
3982         /**
3983          * Returns true if this title resolves to the named special page
3984          *
3985          * @param $name \type{\string} The special page name
3986          * @return boolean
3987          */
3988         public function isSpecial( $name ) {
3989                 if ( $this->getNamespace() == NS_SPECIAL ) {
3990                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
3991                         if ( $name == $thisName ) {
3992                                 return true;
3993                         }
3994                 }
3995                 return false;
3996         }
3997
3998         /**
3999          * If the Title refers to a special page alias which is not the local default,
4000          *
4001          * @return \type{Title} A new Title which points to the local default.
4002          *         Otherwise, returns $this.
4003          */
4004         public function fixSpecialName() {
4005                 if ( $this->getNamespace() == NS_SPECIAL ) {
4006                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
4007                         if ( $canonicalName ) {
4008                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
4009                                 if ( $localName != $this->mDbkeyform ) {
4010                                         return Title::makeTitle( NS_SPECIAL, $localName );
4011                                 }
4012                         }
4013                 }
4014                 return $this;
4015         }
4016
4017         /**
4018          * Is this Title in a namespace which contains content?
4019          * In other words, is this a content page, for the purposes of calculating
4020          * statistics, etc?
4021          *
4022          * @return \type{\bool}
4023          */
4024         public function isContentPage() {
4025                 return MWNamespace::isContent( $this->getNamespace() );
4026         }
4027
4028         /**
4029          * Get all extant redirects to this Title
4030          *
4031          * @param $ns \twotypes{\int,\null} Single namespace to consider;
4032          *            NULL to consider all namespaces
4033          * @return \type{\arrayof{Title}} Redirects to this title
4034          */
4035         public function getRedirectsHere( $ns = null ) {
4036                 $redirs = array();
4037
4038                 $dbr = wfGetDB( DB_SLAVE );
4039                 $where = array(
4040                         'rd_namespace' => $this->getNamespace(),
4041                         'rd_title' => $this->getDBkey(),
4042                         'rd_from = page_id'
4043                 );
4044                 if ( !is_null( $ns ) ) {
4045                         $where['page_namespace'] = $ns;
4046                 }
4047
4048                 $res = $dbr->select(
4049                         array( 'redirect', 'page' ),
4050                         array( 'page_namespace', 'page_title' ),
4051                         $where,
4052                         __METHOD__
4053                 );
4054
4055                 foreach ( $res as $row ) {
4056                         $redirs[] = self::newFromRow( $row );
4057                 }
4058                 return $redirs;
4059         }
4060
4061         /**
4062          * Check if this Title is a valid redirect target
4063          *
4064          * @return \type{\bool}
4065          */
4066         public function isValidRedirectTarget() {
4067                 global $wgInvalidRedirectTargets;
4068
4069                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4070                 if ( $this->isSpecial( 'Userlogout' ) ) {
4071                         return false;
4072                 }
4073
4074                 foreach ( $wgInvalidRedirectTargets as $target ) {
4075                         if ( $this->isSpecial( $target ) ) {
4076                                 return false;
4077                         }
4078                 }
4079
4080                 return true;
4081         }
4082
4083         /**
4084          * Get a backlink cache object
4085          *
4086          * @return object BacklinkCache
4087          */
4088         function getBacklinkCache() {
4089                 if ( is_null( $this->mBacklinkCache ) ) {
4090                         $this->mBacklinkCache = new BacklinkCache( $this );
4091                 }
4092                 return $this->mBacklinkCache;
4093         }
4094
4095         /**
4096          * Whether the magic words __INDEX__ and __NOINDEX__ function for
4097          * this page.
4098          *
4099          * @return Boolean
4100          */
4101         public function canUseNoindex() {
4102                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4103
4104                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4105                         ? $wgContentNamespaces
4106                         : $wgExemptFromUserRobotsControl;
4107
4108                 return !in_array( $this->mNamespace, $bannedNamespaces );
4109
4110         }
4111
4112         /**
4113          * Returns restriction types for the current Title
4114          *
4115          * @return array applicable restriction types
4116          */
4117         public function getRestrictionTypes() {
4118                 global $wgRestrictionTypes;
4119                 $types = $this->exists() ? $wgRestrictionTypes : array( 'create' );
4120
4121                 if ( $this->getNamespace() == NS_FILE ) {
4122                         $types[] = 'upload';
4123                 }
4124
4125                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4126
4127                 return $types;
4128         }
4129
4130         /**
4131          * Returns the raw sort key to be used for categories, with the specified
4132          * prefix.  This will be fed to Language::convertToSortkey() to get a
4133          * binary sortkey that can be used for actual sorting.
4134          *
4135          * @param $prefix string The prefix to be used, specified using
4136          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4137          *   prefix.
4138          * @return string
4139          */
4140         public function getCategorySortkey( $prefix = '' ) {
4141                 $unprefixed = $this->getText();
4142                 if ( $prefix !== '' ) {
4143                         # Separate with a null byte, so the unprefixed part is only used as
4144                         # a tiebreaker when two pages have the exact same prefix -- null
4145                         # sorts before everything else (hopefully).
4146                         return "$prefix\0$unprefixed";
4147                 }
4148                 return $unprefixed;
4149         }
4150 }