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 String: Text with possible redirect
 333          * @return 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 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 Integer: Namespace index
 606          */
 607         public function getNamespace() { return $this->mNamespace; }
 608
 609         /**
 610          * Get the namespace text
 611          *
 612          * @return 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 && count( $errors ) > 0 ) {
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         private function invalidateTitleProtectionCache() {
1606                 unset( $this->mTitleProtection );
1607         }
1608
1609         /**
1610          * Update the title protection status
1611          *
1612          * @param $create_perm \type{\string} Permission required for creation
1613          * @param $reason \type{\string} Reason for protection
1614          * @param $expiry \type{\string} Expiry timestamp
1615          * @return boolean true
1616          */
1617         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1618                 global $wgUser, $wgContLang;
1619
1620                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1621                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1622                         // No change
1623                         return true;
1624                 }
1625
1626                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1627
1628                 $dbw = wfGetDB( DB_MASTER );
1629
1630                 $encodedExpiry = Block::encodeExpiry( $expiry, $dbw );
1631
1632                 $expiry_description = '';
1633                 if ( $encodedExpiry != 'infinity' ) {
1634                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1635                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1636                 } else {
1637                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1638                 }
1639
1640                 # Update protection table
1641                 if ( $create_perm != '' ) {
1642                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1643                                 array(
1644                                         'pt_namespace' => $namespace,
1645                                         'pt_title' => $title,
1646                                         'pt_create_perm' => $create_perm,
1647                                         'pt_timestamp' => Block::encodeExpiry( wfTimestampNow(), $dbw ),
1648                                         'pt_expiry' => $encodedExpiry,
1649                                         'pt_user' => $wgUser->getId(),
1650                                         'pt_reason' => $reason,
1651                                 ), __METHOD__
1652                         );
1653                 } else {
1654                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1655                                 'pt_title' => $title ), __METHOD__ );
1656                 }
1657                 $this->invalidateTitleProtectionCache();
1658
1659                 # Update the protection log
1660                 if ( $dbw->affectedRows() ) {
1661                         $log = new LogPage( 'protect' );
1662
1663                         if ( $create_perm ) {
1664                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1665                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1666                         } else {
1667                                 $log->addEntry( 'unprotect', $this, $reason );
1668                         }
1669                 }
1670
1671                 return true;
1672         }
1673
1674         /**
1675          * Remove any title protection due to page existing
1676          */
1677         public function deleteTitleProtection() {
1678                 $dbw = wfGetDB( DB_MASTER );
1679
1680                 $dbw->delete(
1681                         'protected_titles',
1682                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1683                         __METHOD__
1684                 );
1685                 $this->invalidateTitleProtectionCache();
1686         }
1687
1688         /**
1689          * Would anybody with sufficient privileges be able to move this page?
1690          * Some pages just aren't movable.
1691          *
1692          * @return \type{\bool} TRUE or FALSE
1693          */
1694         public function isMovable() {
1695                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1696         }
1697
1698         /**
1699          * Can $wgUser read this page?
1700          *
1701          * @return \type{\bool}
1702          * @todo fold these checks into userCan()
1703          */
1704         public function userCanRead() {
1705                 global $wgUser, $wgGroupPermissions;
1706
1707                 static $useShortcut = null;
1708
1709                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1710                 if ( is_null( $useShortcut ) ) {
1711                         global $wgRevokePermissions;
1712                         $useShortcut = true;
1713                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1714                                 # Not a public wiki, so no shortcut
1715                                 $useShortcut = false;
1716                         } elseif ( !empty( $wgRevokePermissions ) ) {
1717                                 /*
1718                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1719                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1720                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1721                                  * reading is allowed.
1722                                  */
1723                                 foreach ( $wgRevokePermissions as $perms ) {
1724                                         if ( !empty( $perms['read'] ) ) {
1725                                                 # We might be removing the read right from the user, so no shortcut
1726                                                 $useShortcut = false;
1727                                                 break;
1728                                         }
1729                                 }
1730                         }
1731                 }
1732
1733                 $result = null;
1734                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1735                 if ( $result !== null ) {
1736                         return $result;
1737                 }
1738
1739                 # Shortcut for public wikis, allows skipping quite a bit of code
1740                 if ( $useShortcut ) {
1741                         return true;
1742                 }
1743
1744                 if ( $wgUser->isAllowed( 'read' ) ) {
1745                         return true;
1746                 } else {
1747                         global $wgWhitelistRead;
1748
1749                         /**
1750                          * Always grant access to the login page.
1751                          * Even anons need to be able to log in.
1752                         */
1753                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1754                                 return true;
1755                         }
1756
1757                         /**
1758                          * Bail out if there isn't whitelist
1759                          */
1760                         if ( !is_array( $wgWhitelistRead ) ) {
1761                                 return false;
1762                         }
1763
1764                         /**
1765                          * Check for explicit whitelisting
1766                          */
1767                         $name = $this->getPrefixedText();
1768                         $dbName = $this->getPrefixedDBKey();
1769                         // Check with and without underscores
1770                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1771                                 return true;
1772
1773                         /**
1774                          * Old settings might have the title prefixed with
1775                          * a colon for main-namespace pages
1776                          */
1777                         if ( $this->getNamespace() == NS_MAIN ) {
1778                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1779                                         return true;
1780                                 }
1781                         }
1782
1783                         /**
1784                          * If it's a special page, ditch the subpage bit
1785                          * and check again
1786                          */
1787                         if ( $this->getNamespace() == NS_SPECIAL ) {
1788                                 $name = $this->getDBkey();
1789                                 list( $name, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $name );
1790                                 if ( $name === false ) {
1791                                         # Invalid special page, but we show standard login required message
1792                                         return false;
1793                                 }
1794
1795                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1796                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1797                                         return true;
1798                                 }
1799                         }
1800
1801                 }
1802                 return false;
1803         }
1804
1805         /**
1806          * Is this a talk page of some sort?
1807          *
1808          * @return \type{\bool}
1809          */
1810         public function isTalkPage() {
1811                 return MWNamespace::isTalk( $this->getNamespace() );
1812         }
1813
1814         /**
1815          * Is this a subpage?
1816          *
1817          * @return \type{\bool}
1818          */
1819         public function isSubpage() {
1820                 return MWNamespace::hasSubpages( $this->mNamespace )
1821                         ? strpos( $this->getText(), '/' ) !== false
1822                         : false;
1823         }
1824
1825         /**
1826          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1827          *
1828          * @return \type{\bool}
1829          */
1830         public function hasSubpages() {
1831                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1832                         # Duh
1833                         return false;
1834                 }
1835
1836                 # We dynamically add a member variable for the purpose of this method
1837                 # alone to cache the result.  There's no point in having it hanging
1838                 # around uninitialized in every Title object; therefore we only add it
1839                 # if needed and don't declare it statically.
1840                 if ( isset( $this->mHasSubpages ) ) {
1841                         return $this->mHasSubpages;
1842                 }
1843
1844                 $subpages = $this->getSubpages( 1 );
1845                 if ( $subpages instanceof TitleArray ) {
1846                         return $this->mHasSubpages = (bool)$subpages->count();
1847                 }
1848                 return $this->mHasSubpages = false;
1849         }
1850
1851         /**
1852          * Get all subpages of this page.
1853          *
1854          * @param $limit Maximum number of subpages to fetch; -1 for no limit
1855          * @return mixed TitleArray, or empty array if this page's namespace
1856          *  doesn't allow subpages
1857          */
1858         public function getSubpages( $limit = -1 ) {
1859                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1860                         return array();
1861                 }
1862
1863                 $dbr = wfGetDB( DB_SLAVE );
1864                 $conds['page_namespace'] = $this->getNamespace();
1865                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1866                 $options = array();
1867                 if ( $limit > -1 ) {
1868                         $options['LIMIT'] = $limit;
1869                 }
1870                 return $this->mSubpages = TitleArray::newFromResult(
1871                         $dbr->select( 'page',
1872                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1873                                 $conds,
1874                                 __METHOD__,
1875                                 $options
1876                         )
1877                 );
1878         }
1879
1880         /**
1881          * Could this page contain custom CSS or JavaScript, based
1882          * on the title?
1883          *
1884          * @return \type{\bool}
1885          */
1886         public function isCssOrJsPage() {
1887                 return $this->mNamespace == NS_MEDIAWIKI
1888                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1889         }
1890
1891         /**
1892          * Is this a .css or .js subpage of a user page?
1893          * @return \type{\bool}
1894          */
1895         public function isCssJsSubpage() {
1896                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1897         }
1898
1899         /**
1900          * Is this a *valid* .css or .js subpage of a user page?
1901          *
1902          * @return \type{\bool}
1903          * @deprecated
1904          */
1905         public function isValidCssJsSubpage() {
1906                 return $this->isCssJsSubpage();
1907         }
1908
1909         /**
1910          * Trim down a .css or .js subpage title to get the corresponding skin name
1911          *
1912          * @return string containing skin name from .css or .js subpage title
1913          */
1914         public function getSkinFromCssJsSubpage() {
1915                 $subpage = explode( '/', $this->mTextform );
1916                 $subpage = $subpage[ count( $subpage ) - 1 ];
1917                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1918         }
1919
1920         /**
1921          * Is this a .css subpage of a user page?
1922          *
1923          * @return \type{\bool}
1924          */
1925         public function isCssSubpage() {
1926                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1927         }
1928
1929         /**
1930          * Is this a .js subpage of a user page?
1931          *
1932          * @return \type{\bool}
1933          */
1934         public function isJsSubpage() {
1935                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
1936         }
1937
1938         /**
1939          * Protect css subpages of user pages: can $wgUser edit
1940          * this page?
1941          *
1942          * @return \type{\bool}
1943          * @todo XXX: this might be better using restrictions
1944          */
1945         public function userCanEditCssSubpage() {
1946                 global $wgUser;
1947                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'editusercss' ) )
1948                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1949         }
1950
1951         /**
1952          * Protect js subpages of user pages: can $wgUser edit
1953          * this page?
1954          *
1955          * @return \type{\bool}
1956          * @todo XXX: this might be better using restrictions
1957          */
1958         public function userCanEditJsSubpage() {
1959                 global $wgUser;
1960                 return ( ( $wgUser->isAllowed( 'editusercssjs' ) && $wgUser->isAllowed( 'edituserjs' ) )
1961                        || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
1962         }
1963
1964         /**
1965          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
1966          *
1967          * @return \type{\bool} If the page is subject to cascading restrictions.
1968          */
1969         public function isCascadeProtected() {
1970                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
1971                 return ( $sources > 0 );
1972         }
1973
1974         /**
1975          * Cascading protection: Get the source of any cascading restrictions on this page.
1976          *
1977          * @param $getPages \type{\bool} Whether or not to retrieve the actual pages
1978          *        that the restrictions have come from.
1979          * @return \type{\arrayof{mixed title array, restriction array}} Array of the Title
1980          *         objects of the pages from which cascading restrictions have come,
1981          *         false for none, or true if such restrictions exist, but $getPages was not set.
1982          *         The restriction array is an array of each type, each of which contains a
1983          *         array of unique groups.
1984          */
1985         public function getCascadeProtectionSources( $getPages = true ) {
1986                 $pagerestrictions = array();
1987
1988                 if ( isset( $this->mCascadeSources ) && $getPages ) {
1989                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
1990                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
1991                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
1992                 }
1993
1994                 wfProfileIn( __METHOD__ );
1995
1996                 $dbr = wfGetDB( DB_SLAVE );
1997
1998                 if ( $this->getNamespace() == NS_FILE ) {
1999                         $tables = array( 'imagelinks', 'page_restrictions' );
2000                         $where_clauses = array(
2001                                 'il_to' => $this->getDBkey(),
2002                                 'il_from=pr_page',
2003                                 'pr_cascade' => 1
2004                         );
2005                 } else {
2006                         $tables = array( 'templatelinks', 'page_restrictions' );
2007                         $where_clauses = array(
2008                                 'tl_namespace' => $this->getNamespace(),
2009                                 'tl_title' => $this->getDBkey(),
2010                                 'tl_from=pr_page',
2011                                 'pr_cascade' => 1
2012                         );
2013                 }
2014
2015                 if ( $getPages ) {
2016                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2017                                                    'pr_expiry', 'pr_type', 'pr_level' );
2018                         $where_clauses[] = 'page_id=pr_page';
2019                         $tables[] = 'page';
2020                 } else {
2021                         $cols = array( 'pr_expiry' );
2022                 }
2023
2024                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2025
2026                 $sources = $getPages ? array() : false;
2027                 $now = wfTimestampNow();
2028                 $purgeExpired = false;
2029
2030                 foreach ( $res as $row ) {
2031                         $expiry = Block::decodeExpiry( $row->pr_expiry );
2032                         if ( $expiry > $now ) {
2033                                 if ( $getPages ) {
2034                                         $page_id = $row->pr_page;
2035                                         $page_ns = $row->page_namespace;
2036                                         $page_title = $row->page_title;
2037                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2038                                         # Add groups needed for each restriction type if its not already there
2039                                         # Make sure this restriction type still exists
2040
2041                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2042                                                 $pagerestrictions[$row->pr_type] = array();
2043                                         }
2044
2045                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2046                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2047                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2048                                         }
2049                                 } else {
2050                                         $sources = true;
2051                                 }
2052                         } else {
2053                                 // Trigger lazy purge of expired restrictions from the db
2054                                 $purgeExpired = true;
2055                         }
2056                 }
2057                 if ( $purgeExpired ) {
2058                         Title::purgeExpiredRestrictions();
2059                         $this->invalidateTitleProtectionCache();
2060                 }
2061
2062                 wfProfileOut( __METHOD__ );
2063
2064                 if ( $getPages ) {
2065                         $this->mCascadeSources = $sources;
2066                         $this->mCascadingRestrictions = $pagerestrictions;
2067                 } else {
2068                         $this->mHasCascadingRestrictions = $sources;
2069                 }
2070
2071                 return array( $sources, $pagerestrictions );
2072         }
2073
2074         /**
2075          * Returns cascading restrictions for the current article
2076          *
2077          * @return Boolean
2078          */
2079         function areRestrictionsCascading() {
2080                 if ( !$this->mRestrictionsLoaded ) {
2081                         $this->loadRestrictions();
2082                 }
2083
2084                 return $this->mCascadeRestriction;
2085         }
2086
2087         /**
2088          * Loads a string into mRestrictions array
2089          *
2090          * @param $res \type{Resource} restrictions as an SQL result.
2091          * @param $oldFashionedRestrictions string comma-separated list of page
2092          *        restrictions from page table (pre 1.10)
2093          */
2094         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2095                 $rows = array();
2096
2097                 foreach ( $res as $row ) {
2098                         $rows[] = $row;
2099                 }
2100
2101                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2102         }
2103
2104         /**
2105          * Compiles list of active page restrictions from both page table (pre 1.10)
2106          * and page_restrictions table
2107          *
2108          * @param $rows array of db result objects
2109          * @param $oldFashionedRestrictions string comma-separated list of page
2110          *        restrictions from page table (pre 1.10)
2111          */
2112         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2113                 $dbr = wfGetDB( DB_SLAVE );
2114
2115                 $restrictionTypes = $this->getRestrictionTypes();
2116
2117                 foreach ( $restrictionTypes as $type ) {
2118                         $this->mRestrictions[$type] = array();
2119                         $this->mRestrictionsExpiry[$type] = Block::decodeExpiry( '' );
2120                 }
2121
2122                 $this->mCascadeRestriction = false;
2123
2124                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2125
2126                 if ( $oldFashionedRestrictions === null ) {
2127                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2128                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2129                 }
2130
2131                 if ( $oldFashionedRestrictions != '' ) {
2132
2133                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2134                                 $temp = explode( '=', trim( $restrict ) );
2135                                 if ( count( $temp ) == 1 ) {
2136                                         // old old format should be treated as edit/move restriction
2137                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2138                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2139                                 } else {
2140                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2141                                 }
2142                         }
2143
2144                         $this->mOldRestrictions = true;
2145
2146                 }
2147
2148                 if ( count( $rows ) ) {
2149                         # Current system - load second to make them override.
2150                         $now = wfTimestampNow();
2151                         $purgeExpired = false;
2152
2153                         foreach ( $rows as $row ) {
2154                                 # Cycle through all the restrictions.
2155
2156                                 // Don't take care of restrictions types that aren't allowed
2157
2158                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2159                                         continue;
2160
2161                                 // This code should be refactored, now that it's being used more generally,
2162                                 // But I don't really see any harm in leaving it in Block for now -werdna
2163                                 $expiry = Block::decodeExpiry( $row->pr_expiry );
2164
2165                                 // Only apply the restrictions if they haven't expired!
2166                                 if ( !$expiry || $expiry > $now ) {
2167                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2168                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2169
2170                                         $this->mCascadeRestriction |= $row->pr_cascade;
2171                                 } else {
2172                                         // Trigger a lazy purge of expired restrictions
2173                                         $purgeExpired = true;
2174                                 }
2175                         }
2176
2177                         if ( $purgeExpired ) {
2178                                 Title::purgeExpiredRestrictions();
2179                                 $this->invalidateTitleProtectionCache();
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                                                 $this->invalidateTitleProtectionCache();
2215                                         }
2216                                 } else {
2217                                         $this->mRestrictionsExpiry['create'] = Block::decodeExpiry( '' );
2218                                 }
2219                                 $this->mRestrictionsLoaded = true;
2220                         }
2221                 }
2222         }
2223
2224         /**
2225          * Purge expired restrictions from the page_restrictions table
2226          */
2227         static function purgeExpiredRestrictions() {
2228                 $dbw = wfGetDB( DB_MASTER );
2229                 $dbw->delete(
2230                         'page_restrictions',
2231                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2232                         __METHOD__
2233                 );
2234
2235                 $dbw->delete(
2236                         'protected_titles',
2237                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2238                         __METHOD__
2239                 );
2240         }
2241
2242         /**
2243          * Accessor/initialisation for mRestrictions
2244          *
2245          * @param $action \type{\string} action that permission needs to be checked for
2246          * @return \type{\arrayof{\string}} the array of groups allowed to edit this article
2247          */
2248         public function getRestrictions( $action ) {
2249                 if ( !$this->mRestrictionsLoaded ) {
2250                         $this->loadRestrictions();
2251                 }
2252                 return isset( $this->mRestrictions[$action] )
2253                                 ? $this->mRestrictions[$action]
2254                                 : array();
2255         }
2256
2257         /**
2258          * Get the expiry time for the restriction against a given action
2259          *
2260          * @return 14-char timestamp, or 'infinity' if the page is protected forever
2261          *      or not protected at all, or false if the action is not recognised.
2262          */
2263         public function getRestrictionExpiry( $action ) {
2264                 if ( !$this->mRestrictionsLoaded ) {
2265                         $this->loadRestrictions();
2266                 }
2267                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2268         }
2269
2270         /**
2271          * Is there a version of this page in the deletion archive?
2272          *
2273          * @return \type{\int} the number of archived revisions
2274          */
2275         public function isDeleted() {
2276                 if ( $this->getNamespace() < 0 ) {
2277                         $n = 0;
2278                 } else {
2279                         $dbr = wfGetDB( DB_SLAVE );
2280                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2281                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2282                                 __METHOD__
2283                         );
2284                         if ( $this->getNamespace() == NS_FILE ) {
2285                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2286                                         array( 'fa_name' => $this->getDBkey() ),
2287                                         __METHOD__
2288                                 );
2289                         }
2290                 }
2291                 return (int)$n;
2292         }
2293
2294         /**
2295          * Is there a version of this page in the deletion archive?
2296          *
2297          * @return Boolean
2298          */
2299         public function isDeletedQuick() {
2300                 if ( $this->getNamespace() < 0 ) {
2301                         return false;
2302                 }
2303                 $dbr = wfGetDB( DB_SLAVE );
2304                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2305                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2306                         __METHOD__
2307                 );
2308                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2309                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2310                                 array( 'fa_name' => $this->getDBkey() ),
2311                                 __METHOD__
2312                         );
2313                 }
2314                 return $deleted;
2315         }
2316
2317         /**
2318          * Get the article ID for this Title from the link cache,
2319          * adding it if necessary
2320          *
2321          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select
2322          *  for update
2323          * @return \type{\int} the ID
2324          */
2325         public function getArticleID( $flags = 0 ) {
2326                 if ( $this->getNamespace() < 0 ) {
2327                         return $this->mArticleID = 0;
2328                 }
2329                 $linkCache = LinkCache::singleton();
2330                 if ( $flags & self::GAID_FOR_UPDATE ) {
2331                         $oldUpdate = $linkCache->forUpdate( true );
2332                         $linkCache->clearLink( $this );
2333                         $this->mArticleID = $linkCache->addLinkObj( $this );
2334                         $linkCache->forUpdate( $oldUpdate );
2335                 } else {
2336                         if ( -1 == $this->mArticleID ) {
2337                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2338                         }
2339                 }
2340                 return $this->mArticleID;
2341         }
2342
2343         /**
2344          * Is this an article that is a redirect page?
2345          * Uses link cache, adding it if necessary
2346          *
2347          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2348          * @return \type{\bool}
2349          */
2350         public function isRedirect( $flags = 0 ) {
2351                 if ( !is_null( $this->mRedirect ) ) {
2352                         return $this->mRedirect;
2353                 }
2354                 # Calling getArticleID() loads the field from cache as needed
2355                 if ( !$this->getArticleID( $flags ) ) {
2356                         return $this->mRedirect = false;
2357                 }
2358                 $linkCache = LinkCache::singleton();
2359                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2360
2361                 return $this->mRedirect;
2362         }
2363
2364         /**
2365          * What is the length of this page?
2366          * Uses link cache, adding it if necessary
2367          *
2368          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2369          * @return \type{\bool}
2370          */
2371         public function getLength( $flags = 0 ) {
2372                 if ( $this->mLength != -1 ) {
2373                         return $this->mLength;
2374                 }
2375                 # Calling getArticleID() loads the field from cache as needed
2376                 if ( !$this->getArticleID( $flags ) ) {
2377                         return $this->mLength = 0;
2378                 }
2379                 $linkCache = LinkCache::singleton();
2380                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2381
2382                 return $this->mLength;
2383         }
2384
2385         /**
2386          * What is the page_latest field for this page?
2387          *
2388          * @param $flags \type{\int} a bit field; may be Title::GAID_FOR_UPDATE to select for update
2389          * @return \type{\int} or 0 if the page doesn't exist
2390          */
2391         public function getLatestRevID( $flags = 0 ) {
2392                 if ( $this->mLatestID !== false ) {
2393                         return intval( $this->mLatestID );
2394                 }
2395                 # Calling getArticleID() loads the field from cache as needed
2396                 if ( !$this->getArticleID( $flags ) ) {
2397                         return $this->mLatestID = 0;
2398                 }
2399                 $linkCache = LinkCache::singleton();
2400                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2401
2402                 return $this->mLatestID;
2403         }
2404
2405         /**
2406          * This clears some fields in this object, and clears any associated
2407          * keys in the "bad links" section of the link cache.
2408          *
2409          * - This is called from Article::insertNewArticle() to allow
2410          * loading of the new page_id. It's also called from
2411          * Article::doDeleteArticle()
2412          *
2413          * @param $newid \type{\int} the new Article ID
2414          */
2415         public function resetArticleID( $newid ) {
2416                 $linkCache = LinkCache::singleton();
2417                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2418
2419                 if ( $newid === false ) {
2420                         $this->mArticleID = -1;
2421                 } else {
2422                         $this->mArticleID = intval( $newid );
2423                 }
2424                 $this->mRestrictionsLoaded = false;
2425                 $this->mRestrictions = array();
2426                 $this->mRedirect = null;
2427                 $this->mLength = -1;
2428                 $this->mLatestID = false;
2429         }
2430
2431         /**
2432          * Updates page_touched for this page; called from LinksUpdate.php
2433          *
2434          * @return \type{\bool} true if the update succeded
2435          */
2436         public function invalidateCache() {
2437                 if ( wfReadOnly() ) {
2438                         return;
2439                 }
2440                 $dbw = wfGetDB( DB_MASTER );
2441                 $success = $dbw->update(
2442                         'page',
2443                         array( 'page_touched' => $dbw->timestamp() ),
2444                         $this->pageCond(),
2445                         __METHOD__
2446                 );
2447                 HTMLFileCache::clearFileCache( $this );
2448                 return $success;
2449         }
2450
2451         /**
2452          * Prefix some arbitrary text with the namespace or interwiki prefix
2453          * of this object
2454          *
2455          * @param $name \type{\string} the text
2456          * @return \type{\string} the prefixed text
2457          * @private
2458          */
2459         /* private */ function prefix( $name ) {
2460                 $p = '';
2461                 if ( $this->mInterwiki != '' ) {
2462                         $p = $this->mInterwiki . ':';
2463                 }
2464                 if ( 0 != $this->mNamespace ) {
2465                         $p .= $this->getNsText() . ':';
2466                 }
2467                 return $p . $name;
2468         }
2469
2470         /**
2471          * Returns a simple regex that will match on characters and sequences invalid in titles.
2472          * Note that this doesn't pick up many things that could be wrong with titles, but that
2473          * replacing this regex with something valid will make many titles valid.
2474          *
2475          * @return string regex string
2476          */
2477         static function getTitleInvalidRegex() {
2478                 static $rxTc = false;
2479                 if ( !$rxTc ) {
2480                         # Matching titles will be held as illegal.
2481                         $rxTc = '/' .
2482                                 # Any character not allowed is forbidden...
2483                                 '[^' . Title::legalChars() . ']' .
2484                                 # URL percent encoding sequences interfere with the ability
2485                                 # to round-trip titles -- you can't link to them consistently.
2486                                 '|%[0-9A-Fa-f]{2}' .
2487                                 # XML/HTML character references produce similar issues.
2488                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2489                                 '|&#[0-9]+;' .
2490                                 '|&#x[0-9A-Fa-f]+;' .
2491                                 '/S';
2492                 }
2493
2494                 return $rxTc;
2495         }
2496
2497         /**
2498          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2499          *
2500          * @param $text string containing title to capitalize
2501          * @param $ns int namespace index, defaults to NS_MAIN
2502          * @return String containing capitalized title
2503          */
2504         public static function capitalize( $text, $ns = NS_MAIN ) {
2505                 global $wgContLang;
2506
2507                 if ( MWNamespace::isCapitalized( $ns ) ) {
2508                         return $wgContLang->ucfirst( $text );
2509                 } else {
2510                         return $text;
2511                 }
2512         }
2513
2514         /**
2515          * Secure and split - main initialisation function for this object
2516          *
2517          * Assumes that mDbkeyform has been set, and is urldecoded
2518          * and uses underscores, but not otherwise munged.  This function
2519          * removes illegal characters, splits off the interwiki and
2520          * namespace prefixes, sets the other forms, and canonicalizes
2521          * everything.
2522          *
2523          * @return \type{\bool} true on success
2524          */
2525         private function secureAndSplit() {
2526                 global $wgContLang, $wgLocalInterwiki;
2527
2528                 # Initialisation
2529                 $rxTc = self::getTitleInvalidRegex();
2530
2531                 $this->mInterwiki = $this->mFragment = '';
2532                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2533
2534                 $dbkey = $this->mDbkeyform;
2535
2536                 # Strip Unicode bidi override characters.
2537                 # Sometimes they slip into cut-n-pasted page titles, where the
2538                 # override chars get included in list displays.
2539                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2540
2541                 # Clean up whitespace
2542                 # Note: use of the /u option on preg_replace here will cause
2543                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2544                 # conveniently disabling them.
2545                 #
2546                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2547                 $dbkey = trim( $dbkey, '_' );
2548
2549                 if ( $dbkey == '' ) {
2550                         return false;
2551                 }
2552
2553                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2554                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2555                         return false;
2556                 }
2557
2558                 $this->mDbkeyform = $dbkey;
2559
2560                 # Initial colon indicates main namespace rather than specified default
2561                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2562                 if ( ':' == $dbkey { 0 } ) {
2563                         $this->mNamespace = NS_MAIN;
2564                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2565                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2566                 }
2567
2568                 # Namespace or interwiki prefix
2569                 $firstPass = true;
2570                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2571                 do {
2572                         $m = array();
2573                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2574                                 $p = $m[1];
2575                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2576                                         # Ordinary namespace
2577                                         $dbkey = $m[2];
2578                                         $this->mNamespace = $ns;
2579                                         # For Talk:X pages, check if X has a "namespace" prefix
2580                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2581                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2582                                                         return false; # Disallow Talk:File:x type titles...
2583                                                 } else if ( Interwiki::isValidInterwiki( $x[1] ) ) {
2584                                                         return false; # Disallow Talk:Interwiki:x type titles...
2585                                                 }
2586                                         }
2587                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2588                                         if ( !$firstPass ) {
2589                                                 # Can't make a local interwiki link to an interwiki link.
2590                                                 # That's just crazy!
2591                                                 return false;
2592                                         }
2593
2594                                         # Interwiki link
2595                                         $dbkey = $m[2];
2596                                         $this->mInterwiki = $wgContLang->lc( $p );
2597
2598                                         # Redundant interwiki prefix to the local wiki
2599                                         if ( 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) ) {
2600                                                 if ( $dbkey == '' ) {
2601                                                         # Can't have an empty self-link
2602                                                         return false;
2603                                                 }
2604                                                 $this->mInterwiki = '';
2605                                                 $firstPass = false;
2606                                                 # Do another namespace split...
2607                                                 continue;
2608                                         }
2609
2610                                         # If there's an initial colon after the interwiki, that also
2611                                         # resets the default namespace
2612                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2613                                                 $this->mNamespace = NS_MAIN;
2614                                                 $dbkey = substr( $dbkey, 1 );
2615                                         }
2616                                 }
2617                                 # If there's no recognized interwiki or namespace,
2618                                 # then let the colon expression be part of the title.
2619                         }
2620                         break;
2621                 } while ( true );
2622
2623                 # We already know that some pages won't be in the database!
2624                 #
2625                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2626                         $this->mArticleID = 0;
2627                 }
2628                 $fragment = strstr( $dbkey, '#' );
2629                 if ( false !== $fragment ) {
2630                         $this->setFragment( preg_replace( '/^#_*/', '#', $fragment ) );
2631                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2632                         # remove whitespace again: prevents "Foo_bar_#"
2633                         # becoming "Foo_bar_"
2634                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2635                 }
2636
2637                 # Reject illegal characters.
2638                 #
2639                 if ( preg_match( $rxTc, $dbkey ) ) {
2640                         return false;
2641                 }
2642
2643                 /**
2644                  * Pages with "/./" or "/../" appearing in the URLs will often be un-
2645                  * reachable due to the way web browsers deal with 'relative' URLs.
2646                  * Also, they conflict with subpage syntax.  Forbid them explicitly.
2647                  */
2648                 if ( strpos( $dbkey, '.' ) !== false &&
2649                      ( $dbkey === '.' || $dbkey === '..' ||
2650                        strpos( $dbkey, './' ) === 0  ||
2651                        strpos( $dbkey, '../' ) === 0 ||
2652                        strpos( $dbkey, '/./' ) !== false ||
2653                        strpos( $dbkey, '/../' ) !== false  ||
2654                        substr( $dbkey, -2 ) == '/.' ||
2655                        substr( $dbkey, -3 ) == '/..' ) )
2656                 {
2657                         return false;
2658                 }
2659
2660                 /**
2661                  * Magic tilde sequences? Nu-uh!
2662                  */
2663                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2664                         return false;
2665                 }
2666
2667                 /**
2668                  * Limit the size of titles to 255 bytes.
2669                  * This is typically the size of the underlying database field.
2670                  * We make an exception for special pages, which don't need to be stored
2671                  * in the database, and may edge over 255 bytes due to subpage syntax
2672                  * for long titles, e.g. [[Special:Block/Long name]]
2673                  */
2674                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2675                   strlen( $dbkey ) > 512 )
2676                 {
2677                         return false;
2678                 }
2679
2680                 /**
2681                  * Normally, all wiki links are forced to have
2682                  * an initial capital letter so [[foo]] and [[Foo]]
2683                  * point to the same place.
2684                  *
2685                  * Don't force it for interwikis, since the other
2686                  * site might be case-sensitive.
2687                  */
2688                 $this->mUserCaseDBKey = $dbkey;
2689                 if ( $this->mInterwiki == '' ) {
2690                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2691                 }
2692
2693                 /**
2694                  * Can't make a link to a namespace alone...
2695                  * "empty" local links can only be self-links
2696                  * with a fragment identifier.
2697                  */
2698                 if ( $dbkey == '' &&
2699                         $this->mInterwiki == '' &&
2700                         $this->mNamespace != NS_MAIN ) {
2701                         return false;
2702                 }
2703                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2704                 // IP names are not allowed for accounts, and can only be referring to
2705                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2706                 // there are numerous ways to present the same IP. Having sp:contribs scan
2707                 // them all is silly and having some show the edits and others not is
2708                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2709                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK ) ?
2710                         IP::sanitizeIP( $dbkey ) : $dbkey;
2711                 // Any remaining initial :s are illegal.
2712                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2713                         return false;
2714                 }
2715
2716                 # Fill fields
2717                 $this->mDbkeyform = $dbkey;
2718                 $this->mUrlform = wfUrlencode( $dbkey );
2719
2720                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2721
2722                 return true;
2723         }
2724
2725         /**
2726          * Set the fragment for this title. Removes the first character from the
2727          * specified fragment before setting, so it assumes you're passing it with
2728          * an initial "#".
2729          *
2730          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2731          * Still in active use privately.
2732          *
2733          * @param $fragment \type{\string} text
2734          */
2735         public function setFragment( $fragment ) {
2736                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2737         }
2738
2739         /**
2740          * Get a Title object associated with the talk page of this article
2741          *
2742          * @return Title the object for the talk page
2743          */
2744         public function getTalkPage() {
2745                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2746         }
2747
2748         /**
2749          * Get a title object associated with the subject page of this
2750          * talk page
2751          *
2752          * @return Title the object for the subject page
2753          */
2754         public function getSubjectPage() {
2755                 // Is this the same title?
2756                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2757                 if ( $this->getNamespace() == $subjectNS ) {
2758                         return $this;
2759                 }
2760                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2761         }
2762
2763         /**
2764          * Get an array of Title objects linking to this Title
2765          * Also stores the IDs in the link cache.
2766          *
2767          * WARNING: do not use this function on arbitrary user-supplied titles!
2768          * On heavily-used templates it will max out the memory.
2769          *
2770          * @param $options Array: may be FOR UPDATE
2771          * @param $table String: table name
2772          * @param $prefix String: fields prefix
2773          * @return \type{\arrayof{Title}} the Title objects linking here
2774          */
2775         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2776                 $linkCache = LinkCache::singleton();
2777
2778                 if ( count( $options ) > 0 ) {
2779                         $db = wfGetDB( DB_MASTER );
2780                 } else {
2781                         $db = wfGetDB( DB_SLAVE );
2782                 }
2783
2784                 $res = $db->select(
2785                         array( 'page', $table ),
2786                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2787                         array(
2788                                 "{$prefix}_from=page_id",
2789                                 "{$prefix}_namespace" => $this->getNamespace(),
2790                                 "{$prefix}_title"     => $this->getDBkey() ),
2791                         __METHOD__,
2792                         $options
2793                 );
2794
2795                 $retVal = array();
2796                 if ( $db->numRows( $res ) ) {
2797                         foreach ( $res as $row ) {
2798                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2799                                 if ( $titleObj ) {
2800                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2801                                         $retVal[] = $titleObj;
2802                                 }
2803                         }
2804                 }
2805                 return $retVal;
2806         }
2807
2808         /**
2809          * Get an array of Title objects using this Title as a template
2810          * Also stores the IDs in the link cache.
2811          *
2812          * WARNING: do not use this function on arbitrary user-supplied titles!
2813          * On heavily-used templates it will max out the memory.
2814          *
2815          * @param $options Array: may be FOR UPDATE
2816          * @return \type{\arrayof{Title}} the Title objects linking here
2817          */
2818         public function getTemplateLinksTo( $options = array() ) {
2819                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2820         }
2821
2822         /**
2823          * Get an array of Title objects referring to non-existent articles linked from this page
2824          *
2825          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2826          * @return \type{\arrayof{Title}} the Title objects
2827          */
2828         public function getBrokenLinksFrom() {
2829                 if ( $this->getArticleId() == 0 ) {
2830                         # All links from article ID 0 are false positives
2831                         return array();
2832                 }
2833
2834                 $dbr = wfGetDB( DB_SLAVE );
2835                 $res = $dbr->select(
2836                         array( 'page', 'pagelinks' ),
2837                         array( 'pl_namespace', 'pl_title' ),
2838                         array(
2839                                 'pl_from' => $this->getArticleId(),
2840                                 'page_namespace IS NULL'
2841                         ),
2842                         __METHOD__, array(),
2843                         array(
2844                                 'page' => array(
2845                                         'LEFT JOIN',
2846                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2847                                 )
2848                         )
2849                 );
2850
2851                 $retVal = array();
2852                 foreach ( $res as $row ) {
2853                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2854                 }
2855                 return $retVal;
2856         }
2857
2858
2859         /**
2860          * Get a list of URLs to purge from the Squid cache when this
2861          * page changes
2862          *
2863          * @return \type{\arrayof{\string}} the URLs
2864          */
2865         public function getSquidURLs() {
2866                 global $wgContLang;
2867
2868                 $urls = array(
2869                         $this->getInternalURL(),
2870                         $this->getInternalURL( 'action=history' )
2871                 );
2872
2873                 // purge variant urls as well
2874                 if ( $wgContLang->hasVariants() ) {
2875                         $variants = $wgContLang->getVariants();
2876                         foreach ( $variants as $vCode ) {
2877                                 $urls[] = $this->getInternalURL( '', $vCode );
2878                         }
2879                 }
2880
2881                 return $urls;
2882         }
2883
2884         /**
2885          * Purge all applicable Squid URLs
2886          */
2887         public function purgeSquid() {
2888                 global $wgUseSquid;
2889                 if ( $wgUseSquid ) {
2890                         $urls = $this->getSquidURLs();
2891                         $u = new SquidUpdate( $urls );
2892                         $u->doUpdate();
2893                 }
2894         }
2895
2896         /**
2897          * Move this page without authentication
2898          *
2899          * @param $nt \type{Title} the new page Title
2900          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
2901          */
2902         public function moveNoAuth( &$nt ) {
2903                 return $this->moveTo( $nt, false );
2904         }
2905
2906         /**
2907          * Check whether a given move operation would be valid.
2908          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2909          *
2910          * @param $nt \type{Title} the new title
2911          * @param $auth \type{\bool} indicates whether $wgUser's permissions
2912          *  should be checked
2913          * @param $reason \type{\string} is the log summary of the move, used for spam checking
2914          * @return \type{\mixed} True on success, getUserPermissionsErrors()-like array on failure
2915          */
2916         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2917                 global $wgUser;
2918
2919                 $errors = array();
2920                 if ( !$nt ) {
2921                         // Normally we'd add this to $errors, but we'll get
2922                         // lots of syntax errors if $nt is not an object
2923                         return array( array( 'badtitletext' ) );
2924                 }
2925                 if ( $this->equals( $nt ) ) {
2926                         $errors[] = array( 'selfmove' );
2927                 }
2928                 if ( !$this->isMovable() ) {
2929                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2930                 }
2931                 if ( $nt->getInterwiki() != '' ) {
2932                         $errors[] = array( 'immobile-target-namespace-iw' );
2933                 }
2934                 if ( !$nt->isMovable() ) {
2935                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
2936                 }
2937
2938                 $oldid = $this->getArticleID();
2939                 $newid = $nt->getArticleID();
2940
2941                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2942                         $errors[] = array( 'articleexists' );
2943                 }
2944                 if ( ( $this->getDBkey() == '' ) ||
2945                          ( !$oldid ) ||
2946                      ( $nt->getDBkey() == '' ) ) {
2947                         $errors[] = array( 'badarticleerror' );
2948                 }
2949
2950                 // Image-specific checks
2951                 if ( $this->getNamespace() == NS_FILE ) {
2952                         if ( $nt->getNamespace() != NS_FILE ) {
2953                                 $errors[] = array( 'imagenocrossnamespace' );
2954                         }
2955                         $file = wfLocalFile( $this );
2956                         if ( $file->exists() ) {
2957                                 if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
2958                                         $errors[] = array( 'imageinvalidfilename' );
2959                                 }
2960                                 if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
2961                                         $errors[] = array( 'imagetypemismatch' );
2962                                 }
2963                         }
2964                         $destfile = wfLocalFile( $nt );
2965                         if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destfile->exists() && wfFindFile( $nt ) ) {
2966                                 $errors[] = array( 'file-exists-sharedrepo' );
2967                         }
2968                 }
2969
2970                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
2971                         $errors[] = array( 'nonfile-cannot-move-to-file' );
2972                 }
2973
2974                 if ( $auth ) {
2975                         $errors = wfMergeErrorArrays( $errors,
2976                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
2977                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
2978                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
2979                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
2980                 }
2981
2982                 $match = EditPage::matchSummarySpamRegex( $reason );
2983                 if ( $match !== false ) {
2984                         // This is kind of lame, won't display nice
2985                         $errors[] = array( 'spamprotectiontext' );
2986                 }
2987
2988                 $err = null;
2989                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
2990                         $errors[] = array( 'hookaborted', $err );
2991                 }
2992
2993                 # The move is allowed only if (1) the target doesn't exist, or
2994                 # (2) the target is a redirect to the source, and has no history
2995                 # (so we can undo bad moves right after they're done).
2996
2997                 if ( 0 != $newid ) { # Target exists; check for validity
2998                         if ( !$this->isValidMoveTarget( $nt ) ) {
2999                                 $errors[] = array( 'articleexists' );
3000                         }
3001                 } else {
3002                         $tp = $nt->getTitleProtection();
3003                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3004                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3005                                 $errors[] = array( 'cantmove-titleprotected' );
3006                         }
3007                 }
3008                 if ( empty( $errors ) ) {
3009                         return true;
3010                 }
3011                 return $errors;
3012         }
3013
3014         /**
3015          * Move a title to a new location
3016          *
3017          * @param $nt \type{Title} the new title
3018          * @param $auth \type{\bool} indicates whether $wgUser's permissions
3019          *  should be checked
3020          * @param $reason \type{\string} The reason for the move
3021          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title.
3022          *  Ignored if the user doesn't have the suppressredirect right.
3023          * @return \type{\mixed} true on success, getUserPermissionsErrors()-like array on failure
3024          */
3025         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3026                 global $wgContLang;
3027
3028                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3029                 if ( is_array( $err ) ) {
3030                         return $err;
3031                 }
3032
3033                 // If it is a file, move it first. It is done before all other moving stuff is done because it's hard to revert
3034                 $dbw = wfGetDB( DB_MASTER );
3035                 if ( $this->getNamespace() == NS_FILE ) {
3036                         $file = wfLocalFile( $this );
3037                         if ( $file->exists() ) {
3038                                 $status = $file->move( $nt );
3039                                 if ( !$status->isOk() ) {
3040                                         return $status->getErrorsArray();
3041                                 }
3042                         }
3043                 }
3044
3045                 $pageid = $this->getArticleID();
3046                 $protected = $this->isProtected();
3047                 if ( $nt->exists() ) {
3048                         $err = $this->moveOverExistingRedirect( $nt, $reason, $createRedirect );
3049                         $pageCountChange = ( $createRedirect ? 0 : -1 );
3050                 } else { # Target didn't exist, do normal move.
3051                         $err = $this->moveToNewTitle( $nt, $reason, $createRedirect );
3052                         $pageCountChange = ( $createRedirect ? 1 : 0 );
3053                 }
3054
3055                 if ( is_array( $err ) ) {
3056                         return $err;
3057                 }
3058                 $redirid = $this->getArticleID();
3059
3060                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3061                 // cl_timestamp, which may disturb time-based lists on some sites.
3062                 $prefix = $dbw->selectField(
3063                         'categorylinks',
3064                         'cl_sortkey_prefix',
3065                         array( 'cl_from' => $pageid ),
3066                         __METHOD__
3067                 );
3068                 $dbw->update( 'categorylinks',
3069                         array(
3070                                 'cl_sortkey' => $wgContLang->convertToSortkey( $nt->getCategorySortkey( $prefix ) ),
3071                                 'cl_timestamp=cl_timestamp' ),
3072                         array( 'cl_from' => $pageid ),
3073                         __METHOD__ );
3074
3075                 if ( $protected ) {
3076                         # Protect the redirect title as the title used to be...
3077                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3078                                 array(
3079                                         'pr_page'    => $redirid,
3080                                         'pr_type'    => 'pr_type',
3081                                         'pr_level'   => 'pr_level',
3082                                         'pr_cascade' => 'pr_cascade',
3083                                         'pr_user'    => 'pr_user',
3084                                         'pr_expiry'  => 'pr_expiry'
3085                                 ),
3086                                 array( 'pr_page' => $pageid ),
3087                                 __METHOD__,
3088                                 array( 'IGNORE' )
3089                         );
3090                         # Update the protection log
3091                         $log = new LogPage( 'protect' );
3092                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3093                         if ( $reason ) {
3094                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3095                         }
3096                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) ); // FIXME: $params?
3097                 }
3098
3099                 # Update watchlists
3100                 $oldnamespace = $this->getNamespace() & ~1;
3101                 $newnamespace = $nt->getNamespace() & ~1;
3102                 $oldtitle = $this->getDBkey();
3103                 $newtitle = $nt->getDBkey();
3104
3105                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3106                         WatchedItem::duplicateEntries( $this, $nt );
3107                 }
3108
3109                 # Update search engine
3110                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3111                 $u->doUpdate();
3112                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3113                 $u->doUpdate();
3114
3115                 # Update site_stats
3116                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3117                         # No longer a content page
3118                         # Not viewed, edited, removing
3119                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3120                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3121                         # Now a content page
3122                         # Not viewed, edited, adding
3123                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3124                 } elseif ( $pageCountChange ) {
3125                         # Redirect added
3126                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3127                 } else {
3128                         # Nothing special
3129                         $u = false;
3130                 }
3131                 if ( $u ) {
3132                         $u->doUpdate();
3133                 }
3134                 # Update message cache for interface messages
3135                 global $wgMessageCache;
3136                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3137                         # @bug 17860: old article can be deleted, if this the case,
3138                         # delete it from message cache
3139                         if ( $this->getArticleID() === 0 ) {
3140                                 $wgMessageCache->replace( $this->getDBkey(), false );
3141                         } else {
3142                                 $oldarticle = new Article( $this );
3143                                 $wgMessageCache->replace( $this->getDBkey(), $oldarticle->getContent() );
3144                         }
3145                 }
3146                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3147                         $newarticle = new Article( $nt );
3148                         $wgMessageCache->replace( $nt->getDBkey(), $newarticle->getContent() );
3149                 }
3150
3151                 global $wgUser;
3152                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3153                 return true;
3154         }
3155
3156         /**
3157          * Move page to a title which is at present a redirect to the
3158          * source page
3159          *
3160          * @param $nt \type{Title} the page to move to, which should currently
3161          *  be a redirect
3162          * @param $reason \type{\string} The reason for the move
3163          * @param $createRedirect \type{\bool} Whether to leave a redirect at the old title.
3164          *  Ignored if the user doesn't have the suppressredirect right
3165          */
3166         private function moveOverExistingRedirect( &$nt, $reason = '', $createRedirect = true ) {
3167                 global $wgUseSquid, $wgUser, $wgContLang;
3168
3169                 $comment = wfMsgForContent( '1movedto2_redir', $this->getPrefixedText(), $nt->getPrefixedText() );
3170
3171                 if ( $reason ) {
3172                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3173                 }
3174                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3175                 $comment = $wgContLang->truncate( $comment, 250 );
3176
3177                 $now = wfTimestampNow();
3178                 $newid = $nt->getArticleID();
3179                 $oldid = $this->getArticleID();
3180                 $latest = $this->getLatestRevID();
3181
3182                 $dbw = wfGetDB( DB_MASTER );
3183
3184                 $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3185                 $newns = $nt->getNamespace();
3186                 $newdbk = $nt->getDBkey();
3187
3188                 # Delete the old redirect. We don't save it to history since
3189                 # by definition if we've got here it's rather uninteresting.
3190                 # We have to remove it so that the next step doesn't trigger
3191                 # a conflict on the unique namespace+title index...
3192                 $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3193                 if ( !$dbw->cascadingDeletes() ) {
3194                         $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3195                         global $wgUseTrackbacks;
3196                         if ( $wgUseTrackbacks ) {
3197                                 $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3198                         }
3199                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3200                         $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3201                         $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3202                         $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3203                         $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3204                         $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3205                         $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3206                 }
3207                 // If the redirect was recently created, it may have an entry in recentchanges still
3208                 $dbw->delete( 'recentchanges',
3209                         array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3210                         __METHOD__
3211                 );
3212
3213                 # Save a null revision in the page's history notifying of the move
3214                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3215                 $nullRevId = $nullRevision->insertOn( $dbw );
3216
3217                 $article = new Article( $this );
3218                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3219
3220                 # Change the name of the target page:
3221                 $dbw->update( 'page',
3222                         /* SET */ array(
3223                                 'page_touched'   => $dbw->timestamp( $now ),
3224                                 'page_namespace' => $nt->getNamespace(),
3225                                 'page_title'     => $nt->getDBkey(),
3226                                 'page_latest'    => $nullRevId,
3227                         ),
3228                         /* WHERE */ array( 'page_id' => $oldid ),
3229                         __METHOD__
3230                 );
3231                 $nt->resetArticleID( $oldid );
3232
3233                 # Recreate the redirect, this time in the other direction.
3234                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3235                         $mwRedir = MagicWord::get( 'redirect' );
3236                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3237                         $redirectArticle = new Article( $this );
3238                         $newid = $redirectArticle->insertOn( $dbw );
3239                         $redirectRevision = new Revision( array(
3240                                 'page'    => $newid,
3241                                 'comment' => $comment,
3242                                 'text'    => $redirectText ) );
3243                         $redirectRevision->insertOn( $dbw );
3244                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3245
3246                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3247
3248                         # Now, we record the link from the redirect to the new title.
3249                         # It should have no other outgoing links...
3250                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3251                         $dbw->insert( 'pagelinks',
3252                                 array(
3253                                         'pl_from'      => $newid,
3254                                         'pl_namespace' => $nt->getNamespace(),
3255                                         'pl_title'     => $nt->getDBkey() ),
3256                                 __METHOD__ );
3257                         $redirectSuppressed = false;
3258                 } else {
3259                         $this->resetArticleID( 0 );
3260                         $redirectSuppressed = true;
3261                 }
3262
3263                 # Log the move
3264                 $log = new LogPage( 'move' );
3265                 $log->addEntry( 'move_redir', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3266
3267                 # Purge squid
3268                 if ( $wgUseSquid ) {
3269                         $urls = array_merge( $nt->getSquidURLs(), $this->getSquidURLs() );
3270                         $u = new SquidUpdate( $urls );
3271                         $u->doUpdate();
3272                 }
3273
3274         }
3275
3276         /**
3277          * Move page to non-existing title.
3278          *
3279          * @param $nt \type{Title} the new Title
3280          * @param $reason \type{\string} The reason for the move
3281          * @param $createRedirect \type{\bool} Whether to create a redirect from the old title to the new title
3282          *  Ignored if the user doesn't have the suppressredirect right
3283          */
3284         private function moveToNewTitle( &$nt, $reason = '', $createRedirect = true ) {
3285                 global $wgUser, $wgContLang;
3286
3287                 $comment = wfMsgForContent( '1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3288                 if ( $reason ) {
3289                         $comment .= wfMsgExt( 'colon-separator',
3290                                 array( 'escapenoentities', 'content' ) );
3291                         $comment .= $reason;
3292                 }
3293                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3294                 $comment = $wgContLang->truncate( $comment, 250 );
3295
3296                 $oldid = $this->getArticleID();
3297                 $latest = $this->getLatestRevId();
3298
3299                 $dbw = wfGetDB( DB_MASTER );
3300                 $now = $dbw->timestamp();
3301
3302                 # Save a null revision in the page's history notifying of the move
3303                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3304                 if ( !is_object( $nullRevision ) ) {
3305                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3306                 }
3307                 $nullRevId = $nullRevision->insertOn( $dbw );
3308
3309                 $article = new Article( $this );
3310                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3311
3312                 # Rename page entry
3313                 $dbw->update( 'page',
3314                         /* SET */ array(
3315                                 'page_touched'   => $now,
3316                                 'page_namespace' => $nt->getNamespace(),
3317                                 'page_title'     => $nt->getDBkey(),
3318                                 'page_latest'    => $nullRevId,
3319                         ),
3320                         /* WHERE */ array( 'page_id' => $oldid ),
3321                         __METHOD__
3322                 );
3323                 $nt->resetArticleID( $oldid );
3324
3325                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3326                         # Insert redirect
3327                         $mwRedir = MagicWord::get( 'redirect' );
3328                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3329                         $redirectArticle = new Article( $this );
3330                         $newid = $redirectArticle->insertOn( $dbw );
3331                         $redirectRevision = new Revision( array(
3332                                 'page'    => $newid,
3333                                 'comment' => $comment,
3334                                 'text'    => $redirectText ) );
3335                         $redirectRevision->insertOn( $dbw );
3336                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3337
3338                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3339
3340                         # Record the just-created redirect's linking to the page
3341                         $dbw->insert( 'pagelinks',
3342                                 array(
3343                                         'pl_from'      => $newid,
3344                                         'pl_namespace' => $nt->getNamespace(),
3345                                         'pl_title'     => $nt->getDBkey() ),
3346                                 __METHOD__ );
3347                         $redirectSuppressed = false;
3348                 } else {
3349                         $this->resetArticleID( 0 );
3350                         $redirectSuppressed = true;
3351                 }
3352
3353                 # Log the move
3354                 $log = new LogPage( 'move' );
3355                 $log->addEntry( 'move', $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3356
3357                 # Purge caches as per article creation
3358                 Article::onArticleCreate( $nt );
3359
3360                 # Purge old title from squid
3361                 # The new title, and links to the new title, are purged in Article::onArticleCreate()
3362                 $this->purgeSquid();
3363         }
3364
3365         /**
3366          * Move this page's subpages to be subpages of $nt
3367          *
3368          * @param $nt Title Move target
3369          * @param $auth bool Whether $wgUser's permissions should be checked
3370          * @param $reason string The reason for the move
3371          * @param $createRedirect bool Whether to create redirects from the old subpages to the new ones
3372          *  Ignored if the user doesn't have the 'suppressredirect' right
3373          * @return mixed array with old page titles as keys, and strings (new page titles) or
3374          *  arrays (errors) as values, or an error array with numeric indices if no pages were moved
3375          */
3376         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3377                 global $wgMaximumMovedPages;
3378                 // Check permissions
3379                 if ( !$this->userCan( 'move-subpages' ) ) {
3380                         return array( 'cant-move-subpages' );
3381                 }
3382                 // Do the source and target namespaces support subpages?
3383                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3384                         return array( 'namespace-nosubpages',
3385                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3386                 }
3387                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3388                         return array( 'namespace-nosubpages',
3389                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3390                 }
3391
3392                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3393                 $retval = array();
3394                 $count = 0;
3395                 foreach ( $subpages as $oldSubpage ) {
3396                         $count++;
3397                         if ( $count > $wgMaximumMovedPages ) {
3398                                 $retval[$oldSubpage->getPrefixedTitle()] =
3399                                                 array( 'movepage-max-pages',
3400                                                         $wgMaximumMovedPages );
3401                                 break;
3402                         }
3403
3404                         // We don't know whether this function was called before
3405                         // or after moving the root page, so check both
3406                         // $this and $nt
3407                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3408                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3409                         {
3410                                 // When moving a page to a subpage of itself,
3411                                 // don't move it twice
3412                                 continue;
3413                         }
3414                         $newPageName = preg_replace(
3415                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3416                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3417                                         $oldSubpage->getDBkey() );
3418                         if ( $oldSubpage->isTalkPage() ) {
3419                                 $newNs = $nt->getTalkPage()->getNamespace();
3420                         } else {
3421                                 $newNs = $nt->getSubjectPage()->getNamespace();
3422                         }
3423                         # Bug 14385: we need makeTitleSafe because the new page names may
3424                         # be longer than 255 characters.
3425                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3426
3427                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3428                         if ( $success === true ) {
3429                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3430                         } else {
3431                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3432                         }
3433                 }
3434                 return $retval;
3435         }
3436
3437         /**
3438          * Checks if this page is just a one-rev redirect.
3439          * Adds lock, so don't use just for light purposes.
3440          *
3441          * @return \type{\bool}
3442          */
3443         public function isSingleRevRedirect() {
3444                 $dbw = wfGetDB( DB_MASTER );
3445                 # Is it a redirect?
3446                 $row = $dbw->selectRow( 'page',
3447                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3448                         $this->pageCond(),
3449                         __METHOD__,
3450                         array( 'FOR UPDATE' )
3451                 );
3452                 # Cache some fields we may want
3453                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3454                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3455                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3456                 if ( !$this->mRedirect ) {
3457                         return false;
3458                 }
3459                 # Does the article have a history?
3460                 $row = $dbw->selectField( array( 'page', 'revision' ),
3461                         'rev_id',
3462                         array( 'page_namespace' => $this->getNamespace(),
3463                                 'page_title' => $this->getDBkey(),
3464                                 'page_id=rev_page',
3465                                 'page_latest != rev_id'
3466                         ),
3467                         __METHOD__,
3468                         array( 'FOR UPDATE' )
3469                 );
3470                 # Return true if there was no history
3471                 return ( $row === false );
3472         }
3473
3474         /**
3475          * Checks if $this can be moved to a given Title
3476          * - Selects for update, so don't call it unless you mean business
3477          *
3478          * @param $nt \type{Title} the new title to check
3479          * @return \type{\bool} TRUE or FALSE
3480          */
3481         public function isValidMoveTarget( $nt ) {
3482                 # Is it an existing file?
3483                 if ( $nt->getNamespace() == NS_FILE ) {
3484                         $file = wfLocalFile( $nt );
3485                         if ( $file->exists() ) {
3486                                 wfDebug( __METHOD__ . ": file exists\n" );
3487                                 return false;
3488                         }
3489                 }
3490                 # Is it a redirect with no history?
3491                 if ( !$nt->isSingleRevRedirect() ) {
3492                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3493                         return false;
3494                 }
3495                 # Get the article text
3496                 $rev = Revision::newFromTitle( $nt );
3497                 $text = $rev->getText();
3498                 # Does the redirect point to the source?
3499                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3500                 $m = array();
3501                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3502                         $redirTitle = Title::newFromText( $m[1] );
3503                         if ( !is_object( $redirTitle ) ||
3504                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3505                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3506                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3507                                 return false;
3508                         }
3509                 } else {
3510                         # Fail safe
3511                         wfDebug( __METHOD__ . ": failsafe\n" );
3512                         return false;
3513                 }
3514                 return true;
3515         }
3516
3517         /**
3518          * Can this title be added to a user's watchlist?
3519          *
3520          * @return \type{\bool} TRUE or FALSE
3521          */
3522         public function isWatchable() {
3523                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3524         }
3525
3526         /**
3527          * Get categories to which this Title belongs and return an array of
3528          * categories' names.
3529          *
3530          * @return \type{\array} array an array of parents in the form:
3531          *      $parent => $currentarticle
3532          */
3533         public function getParentCategories() {
3534                 global $wgContLang;
3535
3536                 $titlekey = $this->getArticleId();
3537                 $dbr = wfGetDB( DB_SLAVE );
3538                 $categorylinks = $dbr->tableName( 'categorylinks' );
3539
3540                 # NEW SQL
3541                 $sql = "SELECT * FROM $categorylinks"
3542                      . " WHERE cl_from='$titlekey'"
3543                          . " AND cl_from <> '0'"
3544                          . " ORDER BY cl_sortkey";
3545
3546                 $res = $dbr->query( $sql );
3547                 $data = array();
3548
3549                 if ( $dbr->numRows( $res ) > 0 ) {
3550                         foreach ( $res as $row ) {
3551                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3552                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3553                         }
3554                 }
3555                 return $data;
3556         }
3557
3558         /**
3559          * Get a tree of parent categories
3560          *
3561          * @param $children \type{\array} an array with the children in the keys, to check for circular refs
3562          * @return \type{\array} Tree of parent categories
3563          */
3564         public function getParentCategoryTree( $children = array() ) {
3565                 $stack = array();
3566                 $parents = $this->getParentCategories();
3567
3568                 if ( $parents ) {
3569                         foreach ( $parents as $parent => $current ) {
3570                                 if ( array_key_exists( $parent, $children ) ) {
3571                                         # Circular reference
3572                                         $stack[$parent] = array();
3573                                 } else {
3574                                         $nt = Title::newFromText( $parent );
3575                                         if ( $nt ) {
3576                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3577                                         }
3578                                 }
3579                         }
3580                 }
3581
3582                 return $stack;
3583         }
3584
3585
3586         /**
3587          * Get an associative array for selecting this title from
3588          * the "page" table
3589          *
3590          * @return \type{\array} Selection array
3591          */
3592         public function pageCond() {
3593                 if ( $this->mArticleID > 0 ) {
3594                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3595                         return array( 'page_id' => $this->mArticleID );
3596                 } else {
3597                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3598                 }
3599         }
3600
3601         /**
3602          * Get the revision ID of the previous revision
3603          *
3604          * @param $revId \type{\int} Revision ID. Get the revision that was before this one.
3605          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3606          * @return \twotypes{\int,\bool} Old revision ID, or FALSE if none exists
3607          */
3608         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3609                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3610                 return $db->selectField( 'revision', 'rev_id',
3611                         array(
3612                                 'rev_page' => $this->getArticleId( $flags ),
3613                                 'rev_id < ' . intval( $revId )
3614                         ),
3615                         __METHOD__,
3616                         array( 'ORDER BY' => 'rev_id DESC' )
3617                 );
3618         }
3619
3620         /**
3621          * Get the revision ID of the next revision
3622          *
3623          * @param $revId \type{\int} Revision ID. Get the revision that was after this one.
3624          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3625          * @return \twotypes{\int,\bool} Next revision ID, or FALSE if none exists
3626          */
3627         public function getNextRevisionID( $revId, $flags = 0 ) {
3628                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3629                 return $db->selectField( 'revision', 'rev_id',
3630                         array(
3631                                 'rev_page' => $this->getArticleId( $flags ),
3632                                 'rev_id > ' . intval( $revId )
3633                         ),
3634                         __METHOD__,
3635                         array( 'ORDER BY' => 'rev_id' )
3636                 );
3637         }
3638
3639         /**
3640          * Get the first revision of the page
3641          *
3642          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3643          * @return Revision (or NULL if page doesn't exist)
3644          */
3645         public function getFirstRevision( $flags = 0 ) {
3646                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3647                 $pageId = $this->getArticleId( $flags );
3648                 if ( !$pageId ) {
3649                         return null;
3650                 }
3651                 $row = $db->selectRow( 'revision', '*',
3652                         array( 'rev_page' => $pageId ),
3653                         __METHOD__,
3654                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3655                 );
3656                 if ( !$row ) {
3657                         return null;
3658                 } else {
3659                         return new Revision( $row );
3660                 }
3661         }
3662
3663         /**
3664          * Check if this is a new page
3665          *
3666          * @return bool
3667          */
3668         public function isNewPage() {
3669                 $dbr = wfGetDB( DB_SLAVE );
3670                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3671         }
3672
3673         /**
3674          * Get the oldest revision timestamp of this page
3675          *
3676          * @return String: MW timestamp
3677          */
3678         public function getEarliestRevTime() {
3679                 $dbr = wfGetDB( DB_SLAVE );
3680                 if ( $this->exists() ) {
3681                         $min = $dbr->selectField( 'revision',
3682                                 'MIN(rev_timestamp)',
3683                                 array( 'rev_page' => $this->getArticleId() ),
3684                                 __METHOD__ );
3685                         return wfTimestampOrNull( TS_MW, $min );
3686                 }
3687                 return null;
3688         }
3689
3690         /**
3691          * Get the number of revisions between the given revision IDs.
3692          * Used for diffs and other things that really need it.
3693          *
3694          * @param $old \type{\int} Revision ID.
3695          * @param $new \type{\int} Revision ID.
3696          * @return \type{\int} Number of revisions between these IDs.
3697          */
3698         public function countRevisionsBetween( $old, $new ) {
3699                 $dbr = wfGetDB( DB_SLAVE );
3700                 return (int)$dbr->selectField( 'revision', 'count(*)',
3701                         'rev_page = ' . intval( $this->getArticleId() ) .
3702                         ' AND rev_id > ' . intval( $old ) .
3703                         ' AND rev_id < ' . intval( $new ),
3704                         __METHOD__
3705                 );
3706         }
3707
3708         /**
3709          * Get the number of authors between the given revision IDs.
3710          * Used for diffs and other things that really need it.
3711          *
3712          * @param $fromRevId \type{\int} Revision ID (first before range)
3713          * @param $toRevId \type{\int} Revision ID (first after range)
3714          * @param $limit \type{\int} Maximum number of authors
3715          * @param $flags \type{\int} Title::GAID_FOR_UPDATE
3716          * @return \type{\int}
3717          */
3718         public function countAuthorsBetween( $fromRevId, $toRevId, $limit, $flags = 0 ) {
3719                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3720                 $res = $db->select( 'revision', 'DISTINCT rev_user_text',
3721                         array(
3722                                 'rev_page = ' . $this->getArticleID(),
3723                                 'rev_id > ' . (int)$fromRevId,
3724                                 'rev_id < ' . (int)$toRevId
3725                         ), __METHOD__,
3726                         array( 'LIMIT' => $limit )
3727                 );
3728                 return (int)$db->numRows( $res );
3729         }
3730
3731         /**
3732          * Compare with another title.
3733          *
3734          * @param $title \type{Title}
3735          * @return \type{\bool} TRUE or FALSE
3736          */
3737         public function equals( Title $title ) {
3738                 // Note: === is necessary for proper matching of number-like titles.
3739                 return $this->getInterwiki() === $title->getInterwiki()
3740                         && $this->getNamespace() == $title->getNamespace()
3741                         && $this->getDBkey() === $title->getDBkey();
3742         }
3743
3744         /**
3745          * Callback for usort() to do title sorts by (namespace, title)
3746          *
3747          * @return Integer: result of string comparison, or namespace comparison
3748          */
3749         public static function compare( $a, $b ) {
3750                 if ( $a->getNamespace() == $b->getNamespace() ) {
3751                         return strcmp( $a->getText(), $b->getText() );
3752                 } else {
3753                         return $a->getNamespace() - $b->getNamespace();
3754                 }
3755         }
3756
3757         /**
3758          * Return a string representation of this title
3759          *
3760          * @return \type{\string} String representation of this title
3761          */
3762         public function __toString() {
3763                 return $this->getPrefixedText();
3764         }
3765
3766         /**
3767          * Check if page exists.  For historical reasons, this function simply
3768          * checks for the existence of the title in the page table, and will
3769          * thus return false for interwiki links, special pages and the like.
3770          * If you want to know if a title can be meaningfully viewed, you should
3771          * probably call the isKnown() method instead.
3772          *
3773          * @return \type{\bool}
3774          */
3775         public function exists() {
3776                 return $this->getArticleId() != 0;
3777         }
3778
3779         /**
3780          * Should links to this title be shown as potentially viewable (i.e. as
3781          * "bluelinks"), even if there's no record by this title in the page
3782          * table?
3783          *
3784          * This function is semi-deprecated for public use, as well as somewhat
3785          * misleadingly named.  You probably just want to call isKnown(), which
3786          * calls this function internally.
3787          *
3788          * (ISSUE: Most of these checks are cheap, but the file existence check
3789          * can potentially be quite expensive.  Including it here fixes a lot of
3790          * existing code, but we might want to add an optional parameter to skip
3791          * it and any other expensive checks.)
3792          *
3793          * @return \type{\bool}
3794          */
3795         public function isAlwaysKnown() {
3796                 if ( $this->mInterwiki != '' ) {
3797                         return true;  // any interwiki link might be viewable, for all we know
3798                 }
3799                 switch( $this->mNamespace ) {
3800                         case NS_MEDIA:
3801                         case NS_FILE:
3802                                 return (bool)wfFindFile( $this );  // file exists, possibly in a foreign repo
3803                         case NS_SPECIAL:
3804                                 return SpecialPage::exists( $this->getDBkey() );  // valid special page
3805                         case NS_MAIN:
3806                                 return $this->mDbkeyform == '';  // selflink, possibly with fragment
3807                         case NS_MEDIAWIKI:
3808                                 // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
3809                                 // the full l10n of that language to be loaded. That takes much memory and
3810                                 // isn't needed. So we strip the language part away.
3811                                 list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3812                                 return (bool)wfMsgWeirdKey( $basename );  // known system message
3813                         default:
3814                                 return false;
3815                 }
3816         }
3817
3818         /**
3819          * Does this title refer to a page that can (or might) be meaningfully
3820          * viewed?  In particular, this function may be used to determine if
3821          * links to the title should be rendered as "bluelinks" (as opposed to
3822          * "redlinks" to non-existent pages).
3823          *
3824          * @return \type{\bool}
3825          */
3826         public function isKnown() {
3827                 return $this->isAlwaysKnown() || $this->exists();
3828         }
3829
3830         /**
3831          * Does this page have source text?
3832          *
3833          * @return Boolean
3834          */
3835         public function hasSourceText() {
3836                 if ( $this->exists() ) {
3837                         return true;
3838                 }
3839
3840                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3841                         // If the page doesn't exist but is a known system message, default
3842                         // message content will be displayed, same for language subpages
3843                         // Also, if the page is form Mediawiki:message/lang, calling wfMsgWeirdKey
3844                         // causes the full l10n of that language to be loaded. That takes much
3845                         // memory and isn't needed. So we strip the language part away.
3846                         list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
3847                         return (bool)wfMsgWeirdKey( $basename );
3848                 }
3849
3850                 return false;
3851         }
3852
3853         /**
3854          * Is this in a namespace that allows actual pages?
3855          *
3856          * @return \type{\bool}
3857          * @internal note -- uses hardcoded namespace index instead of constants
3858          */
3859         public function canExist() {
3860                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3861         }
3862
3863         /**
3864          * Update page_touched timestamps and send squid purge messages for
3865          * pages linking to this title. May be sent to the job queue depending
3866          * on the number of links. Typically called on create and delete.
3867          */
3868         public function touchLinks() {
3869                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3870                 $u->doUpdate();
3871
3872                 if ( $this->getNamespace() == NS_CATEGORY ) {
3873                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3874                         $u->doUpdate();
3875                 }
3876         }
3877
3878         /**
3879          * Get the last touched timestamp
3880          *
3881          * @param $db DatabaseBase: optional db
3882          * @return \type{\string} Last touched timestamp
3883          */
3884         public function getTouched( $db = null ) {
3885                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3886                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3887                 return $touched;
3888         }
3889
3890         /**
3891          * Get the timestamp when this page was updated since the user last saw it.
3892          *
3893          * @param $user User
3894          * @return Mixed: string/null
3895          */
3896         public function getNotificationTimestamp( $user = null ) {
3897                 global $wgUser, $wgShowUpdatedMarker;
3898                 // Assume current user if none given
3899                 if ( !$user ) {
3900                         $user = $wgUser;
3901                 }
3902                 // Check cache first
3903                 $uid = $user->getId();
3904                 if ( isset( $this->mNotificationTimestamp[$uid] ) ) {
3905                         return $this->mNotificationTimestamp[$uid];
3906                 }
3907                 if ( !$uid || !$wgShowUpdatedMarker ) {
3908                         return $this->mNotificationTimestamp[$uid] = false;
3909                 }
3910                 // Don't cache too much!
3911                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3912                         $this->mNotificationTimestamp = array();
3913                 }
3914                 $dbr = wfGetDB( DB_SLAVE );
3915                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3916                         'wl_notificationtimestamp',
3917                         array( 'wl_namespace' => $this->getNamespace(),
3918                                 'wl_title' => $this->getDBkey(),
3919                                 'wl_user' => $user->getId()
3920                         ),
3921                         __METHOD__
3922                 );
3923                 return $this->mNotificationTimestamp[$uid];
3924         }
3925
3926         /**
3927          * Get the trackback URL for this page
3928          *
3929          * @return \type{\string} Trackback URL
3930          */
3931         public function trackbackURL() {
3932                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3933
3934                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3935                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3936         }
3937
3938         /**
3939          * Get the trackback RDF for this page
3940          *
3941          * @return \type{\string} Trackback RDF
3942          */
3943         public function trackbackRDF() {
3944                 $url = htmlspecialchars( $this->getFullURL() );
3945                 $title = htmlspecialchars( $this->getText() );
3946                 $tburl = $this->trackbackURL();
3947
3948                 // Autodiscovery RDF is placed in comments so HTML validator
3949                 // won't barf. This is a rather icky workaround, but seems
3950                 // frequently used by this kind of RDF thingy.
3951                 //
3952                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3953                 return "<!--
3954 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3955          xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3956          xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3957 <rdf:Description
3958    rdf:about=\"$url\"
3959    dc:identifier=\"$url\"
3960    dc:title=\"$title\"
3961    trackback:ping=\"$tburl\" />
3962 </rdf:RDF>
3963 -->";
3964         }
3965
3966         /**
3967          * Generate strings used for xml 'id' names in monobook tabs
3968          *
3969          * @param $prepend string defaults to 'nstab-'
3970          * @return \type{\string} XML 'id' name
3971          */
3972         public function getNamespaceKey( $prepend = 'nstab-' ) {
3973                 global $wgContLang;
3974                 // Gets the subject namespace if this title
3975                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
3976                 // Checks if cononical namespace name exists for namespace
3977                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
3978                         // Uses canonical namespace name
3979                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
3980                 } else {
3981                         // Uses text of namespace
3982                         $namespaceKey = $this->getSubjectNsText();
3983                 }
3984                 // Makes namespace key lowercase
3985                 $namespaceKey = $wgContLang->lc( $namespaceKey );
3986                 // Uses main
3987                 if ( $namespaceKey == '' ) {
3988                         $namespaceKey = 'main';
3989                 }
3990                 // Changes file to image for backwards compatibility
3991                 if ( $namespaceKey == 'file' ) {
3992                         $namespaceKey = 'image';
3993                 }
3994                 return $prepend . $namespaceKey;
3995         }
3996
3997         /**
3998          * Returns true if this is a special page.
3999          *
4000          * @return boolean
4001          */
4002         public function isSpecialPage() {
4003                 return $this->getNamespace() == NS_SPECIAL;
4004         }
4005
4006         /**
4007          * Returns true if this title resolves to the named special page
4008          *
4009          * @param $name \type{\string} The special page name
4010          * @return boolean
4011          */
4012         public function isSpecial( $name ) {
4013                 if ( $this->getNamespace() == NS_SPECIAL ) {
4014                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
4015                         if ( $name == $thisName ) {
4016                                 return true;
4017                         }
4018                 }
4019                 return false;
4020         }
4021
4022         /**
4023          * If the Title refers to a special page alias which is not the local default,
4024          *
4025          * @return \type{Title} A new Title which points to the local default.
4026          *         Otherwise, returns $this.
4027          */
4028         public function fixSpecialName() {
4029                 if ( $this->getNamespace() == NS_SPECIAL ) {
4030                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
4031                         if ( $canonicalName ) {
4032                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
4033                                 if ( $localName != $this->mDbkeyform ) {
4034                                         return Title::makeTitle( NS_SPECIAL, $localName );
4035                                 }
4036                         }
4037                 }
4038                 return $this;
4039         }
4040
4041         /**
4042          * Is this Title in a namespace which contains content?
4043          * In other words, is this a content page, for the purposes of calculating
4044          * statistics, etc?
4045          *
4046          * @return Boolean
4047          */
4048         public function isContentPage() {
4049                 return MWNamespace::isContent( $this->getNamespace() );
4050         }
4051
4052         /**
4053          * Get all extant redirects to this Title
4054          *
4055          * @param $ns \twotypes{\int,\null} Single namespace to consider;
4056          *            NULL to consider all namespaces
4057          * @return \type{\arrayof{Title}} Redirects to this title
4058          */
4059         public function getRedirectsHere( $ns = null ) {
4060                 $redirs = array();
4061
4062                 $dbr = wfGetDB( DB_SLAVE );
4063                 $where = array(
4064                         'rd_namespace' => $this->getNamespace(),
4065                         'rd_title' => $this->getDBkey(),
4066                         'rd_from = page_id'
4067                 );
4068                 if ( !is_null( $ns ) ) {
4069                         $where['page_namespace'] = $ns;
4070                 }
4071
4072                 $res = $dbr->select(
4073                         array( 'redirect', 'page' ),
4074                         array( 'page_namespace', 'page_title' ),
4075                         $where,
4076                         __METHOD__
4077                 );
4078
4079                 foreach ( $res as $row ) {
4080                         $redirs[] = self::newFromRow( $row );
4081                 }
4082                 return $redirs;
4083         }
4084
4085         /**
4086          * Check if this Title is a valid redirect target
4087          *
4088          * @return \type{\bool}
4089          */
4090         public function isValidRedirectTarget() {
4091                 global $wgInvalidRedirectTargets;
4092
4093                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4094                 if ( $this->isSpecial( 'Userlogout' ) ) {
4095                         return false;
4096                 }
4097
4098                 foreach ( $wgInvalidRedirectTargets as $target ) {
4099                         if ( $this->isSpecial( $target ) ) {
4100                                 return false;
4101                         }
4102                 }
4103
4104                 return true;
4105         }
4106
4107         /**
4108          * Get a backlink cache object
4109          *
4110          * @return object BacklinkCache
4111          */
4112         function getBacklinkCache() {
4113                 if ( is_null( $this->mBacklinkCache ) ) {
4114                         $this->mBacklinkCache = new BacklinkCache( $this );
4115                 }
4116                 return $this->mBacklinkCache;
4117         }
4118
4119         /**
4120          * Whether the magic words __INDEX__ and __NOINDEX__ function for
4121          * this page.
4122          *
4123          * @return Boolean
4124          */
4125         public function canUseNoindex() {
4126                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4127
4128                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4129                         ? $wgContentNamespaces
4130                         : $wgExemptFromUserRobotsControl;
4131
4132                 return !in_array( $this->mNamespace, $bannedNamespaces );
4133
4134         }
4135
4136         /**
4137          * Returns restriction types for the current Title
4138          *
4139          * @return array applicable restriction types
4140          */
4141         public function getRestrictionTypes() {
4142                 global $wgRestrictionTypes;
4143                 $types = $this->exists() ? $wgRestrictionTypes : array( 'create' );
4144
4145                 if ( $this->getNamespace() == NS_FILE ) {
4146                         $types[] = 'upload';
4147                 }
4148
4149                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4150
4151                 return $types;
4152         }
4153
4154         /**
4155          * Returns the raw sort key to be used for categories, with the specified
4156          * prefix.  This will be fed to Language::convertToSortkey() to get a
4157          * binary sortkey that can be used for actual sorting.
4158          *
4159          * @param $prefix string The prefix to be used, specified using
4160          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4161          *   prefix.
4162          * @return string
4163          */
4164         public function getCategorySortkey( $prefix = '' ) {
4165                 $unprefixed = $this->getText();
4166                 if ( $prefix !== '' ) {
4167                         # Separate with a null byte, so the unprefixed part is only used as
4168                         # a tiebreaker when two pages have the exact same prefix -- null
4169                         # sorts before everything else (hopefully).
4170                         return "$prefix\0$unprefixed";
4171                 }
4172                 return $unprefixed;
4173         }
4174 }