includes/Title.php

   1 <?php
   2 /**
   3  * See title.txt
   4  * @file
   5  */
   6
   7 /**
   8  * @todo:  determine if it is really necessary to load this.  Appears to be left over from pre-autoloader versions, and
   9  *   is only really needed to provide access to constant UTF8_REPLACEMENT, which actually resides in UtfNormalDefines.php
  10  *   and is loaded by UtfNormalUtil.php, which is loaded by UtfNormal.php.
  11  */
  12 if ( !class_exists( 'UtfNormal' ) ) {
  13         require_once( dirname( __FILE__ ) . '/normal/UtfNormal.php' );
  14 }
  15
  16 /**
  17  * @deprecated This used to be a define, but was moved to
  18  * Title::GAID_FOR_UPDATE in 1.17. This will probably be removed in 1.18
  19  */
  20 define( 'GAID_FOR_UPDATE', Title::GAID_FOR_UPDATE );
  21
  22 /**
  23  * Represents a title within MediaWiki.
  24  * Optionally may contain an interwiki designation or namespace.
  25  * @note This class can fetch various kinds of data from the database;
  26  *       however, it does so inefficiently.
  27  *
  28  * @internal documentation reviewed 15 Mar 2010
  29  */
  30 class Title {
  31         /** @name Static cache variables */
  32         // @{
  33         static private $titleCache = array();
  34         // @}
  35
  36         /**
  37          * Title::newFromText maintains a cache to avoid expensive re-normalization of
  38          * commonly used titles. On a batch operation this can become a memory leak
  39          * if not bounded. After hitting this many titles reset the cache.
  40          */
  41         const CACHE_MAX = 1000;
  42
  43         /**
  44          * Used to be GAID_FOR_UPDATE define. Used with getArticleID() and friends
  45          * to use the master DB
  46          */
  47         const GAID_FOR_UPDATE = 1;
  48
  49
  50         /**
  51          * @name Private member variables
  52          * Please use the accessor functions instead.
  53          * @private
  54          */
  55         // @{
  56
  57         var $mTextform = '';              // /< Text form (spaces not underscores) of the main part
  58         var $mUrlform = '';               // /< URL-encoded form of the main part
  59         var $mDbkeyform = '';             // /< Main part with underscores
  60         var $mUserCaseDBKey;              // /< DB key with the initial letter in the case specified by the user
  61         var $mNamespace = NS_MAIN;        // /< Namespace index, i.e. one of the NS_xxxx constants
  62         var $mInterwiki = '';             // /< Interwiki prefix (or null string)
  63         var $mFragment;                   // /< Title fragment (i.e. the bit after the #)
  64         var $mArticleID = -1;             // /< Article ID, fetched from the link cache on demand
  65         var $mLatestID = false;           // /< ID of most recent revision
  66         var $mRestrictions = array();     // /< Array of groups allowed to edit this article
  67         var $mOldRestrictions = false;
  68         var $mCascadeRestriction;         ///< Cascade restrictions on this page to included templates and images?
  69         var $mCascadingRestrictions;      // Caching the results of getCascadeProtectionSources
  70         var $mRestrictionsExpiry = array(); ///< When do the restrictions on this page expire?
  71         var $mHasCascadingRestrictions;   ///< Are cascading restrictions in effect on this page?
  72         var $mCascadeSources;             ///< Where are the cascading restrictions coming from on this page?
  73         var $mRestrictionsLoaded = false; ///< Boolean for initialisation on demand
  74         var $mPrefixedText;               ///< Text form including namespace/interwiki, initialised on demand
  75         var $mTitleProtection;            ///< Cached value for getTitleProtection (create protection)
  76         # Don't change the following default, NS_MAIN is hardcoded in several
  77         # places.  See bug 696.
  78         var $mDefaultNamespace = NS_MAIN; // /< Namespace index when there is no namespace
  79                                                                           # Zero except in {{transclusion}} tags
  80         var $mWatched = null;             // /< Is $wgUser watching this page? null if unfilled, accessed through userIsWatching()
  81         var $mLength = -1;                // /< The page length, 0 for special pages
  82         var $mRedirect = null;            // /< Is the article at this title a redirect?
  83         var $mNotificationTimestamp = array(); // /< Associative array of user ID -> timestamp/false
  84         var $mBacklinkCache = null;       // /< Cache of links to this title
  85         // @}
  86
  87
  88         /**
  89          * Constructor
  90          * @private
  91          */
  92         /* private */ function __construct() { }
  93
  94         /**
  95          * Create a new Title from a prefixed DB key
  96          *
  97          * @param $key String the database key, which has underscores
  98          *      instead of spaces, possibly including namespace and
  99          *      interwiki prefixes
 100          * @return Title, or NULL on an error
 101          */
 102         public static function newFromDBkey( $key ) {
 103                 $t = new Title();
 104                 $t->mDbkeyform = $key;
 105                 if ( $t->secureAndSplit() ) {
 106                         return $t;
 107                 } else {
 108                         return null;
 109                 }
 110         }
 111
 112         /**
 113          * Create a new Title from text, such as what one would find in a link. De-
 114          * codes any HTML entities in the text.
 115          *
 116          * @param $text String the link text; spaces, prefixes, and an
 117          *   initial ':' indicating the main namespace are accepted.
 118          * @param $defaultNamespace Int the namespace to use if none is speci-
 119          *   fied by a prefix.  If you want to force a specific namespace even if
 120          *   $text might begin with a namespace prefix, use makeTitle() or
 121          *   makeTitleSafe().
 122          * @return Title, or null on an error.
 123          */
 124         public static function newFromText( $text, $defaultNamespace = NS_MAIN ) {
 125                 if ( is_object( $text ) ) {
 126                         throw new MWException( 'Title::newFromText given an object' );
 127                 }
 128
 129                 /**
 130                  * Wiki pages often contain multiple links to the same page.
 131                  * Title normalization and parsing can become expensive on
 132                  * pages with many links, so we can save a little time by
 133                  * caching them.
 134                  *
 135                  * In theory these are value objects and won't get changed...
 136                  */
 137                 if ( $defaultNamespace == NS_MAIN && isset( Title::$titleCache[$text] ) ) {
 138                         return Title::$titleCache[$text];
 139                 }
 140
 141                 # Convert things like &eacute; &#257; or &#x3017; into normalized (bug 14952) text
 142                 $filteredText = Sanitizer::decodeCharReferencesAndNormalize( $text );
 143
 144                 $t = new Title();
 145                 $t->mDbkeyform = str_replace( ' ', '_', $filteredText );
 146                 $t->mDefaultNamespace = $defaultNamespace;
 147
 148                 static $cachedcount = 0 ;
 149                 if ( $t->secureAndSplit() ) {
 150                         if ( $defaultNamespace == NS_MAIN ) {
 151                                 if ( $cachedcount >= self::CACHE_MAX ) {
 152                                         # Avoid memory leaks on mass operations...
 153                                         Title::$titleCache = array();
 154                                         $cachedcount = 0;
 155                                 }
 156                                 $cachedcount++;
 157                                 Title::$titleCache[$text] =& $t;
 158                         }
 159                         return $t;
 160                 } else {
 161                         $ret = null;
 162                         return $ret;
 163                 }
 164         }
 165
 166         /**
 167          * THIS IS NOT THE FUNCTION YOU WANT. Use Title::newFromText().
 168          *
 169          * Example of wrong and broken code:
 170          * $title = Title::newFromURL( $wgRequest->getVal( 'title' ) );
 171          *
 172          * Example of right code:
 173          * $title = Title::newFromText( $wgRequest->getVal( 'title' ) );
 174          *
 175          * Create a new Title from URL-encoded text. Ensures that
 176          * the given title's length does not exceed the maximum.
 177          *
 178          * @param $url String the title, as might be taken from a URL
 179          * @return Title the new object, or NULL on an error
 180          */
 181         public static function newFromURL( $url ) {
 182                 global $wgLegalTitleChars;
 183                 $t = new Title();
 184
 185                 # For compatibility with old buggy URLs. "+" is usually not valid in titles,
 186                 # but some URLs used it as a space replacement and they still come
 187                 # from some external search tools.
 188                 if ( strpos( $wgLegalTitleChars, '+' ) === false ) {
 189                         $url = str_replace( '+', ' ', $url );
 190                 }
 191
 192                 $t->mDbkeyform = str_replace( ' ', '_', $url );
 193                 if ( $t->secureAndSplit() ) {
 194                         return $t;
 195                 } else {
 196                         return null;
 197                 }
 198         }
 199
 200         /**
 201          * Create a new Title from an article ID
 202          *
 203          * @param $id Int the page_id corresponding to the Title to create
 204          * @param $flags Int use Title::GAID_FOR_UPDATE to use master
 205          * @return Title the new object, or NULL on an error
 206          */
 207         public static function newFromID( $id, $flags = 0 ) {
 208                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
 209                 $row = $db->selectRow( 'page', '*', array( 'page_id' => $id ), __METHOD__ );
 210                 if ( $row !== false ) {
 211                         $title = Title::newFromRow( $row );
 212                 } else {
 213                         $title = null;
 214                 }
 215                 return $title;
 216         }
 217
 218         /**
 219          * Make an array of titles from an array of IDs
 220          *
 221          * @param $ids Array of Int Array of IDs
 222          * @return Array of Titles
 223          */
 224         public static function newFromIDs( $ids ) {
 225                 if ( !count( $ids ) ) {
 226                         return array();
 227                 }
 228                 $dbr = wfGetDB( DB_SLAVE );
 229
 230                 $res = $dbr->select(
 231                         'page',
 232                         array(
 233                                 'page_namespace', 'page_title', 'page_id',
 234                                 'page_len', 'page_is_redirect', 'page_latest',
 235                         ),
 236                         array( 'page_id' => $ids ),
 237                         __METHOD__
 238                 );
 239
 240                 $titles = array();
 241                 foreach ( $res as $row ) {
 242                         $titles[] = Title::newFromRow( $row );
 243                 }
 244                 return $titles;
 245         }
 246
 247         /**
 248          * Make a Title object from a DB row
 249          *
 250          * @param $row Object database row (needs at least page_title,page_namespace)
 251          * @return Title corresponding Title
 252          */
 253         public static function newFromRow( $row ) {
 254                 $t = self::makeTitle( $row->page_namespace, $row->page_title );
 255
 256                 $t->mArticleID = isset( $row->page_id ) ? intval( $row->page_id ) : -1;
 257                 $t->mLength = isset( $row->page_len ) ? intval( $row->page_len ) : -1;
 258                 $t->mRedirect = isset( $row->page_is_redirect ) ? (bool)$row->page_is_redirect : null;
 259                 $t->mLatestID = isset( $row->page_latest ) ? intval( $row->page_latest ) : false;
 260
 261                 return $t;
 262         }
 263
 264         /**
 265          * Create a new Title from a namespace index and a DB key.
 266          * It's assumed that $ns and $title are *valid*, for instance when
 267          * they came directly from the database or a special page name.
 268          * For convenience, spaces are converted to underscores so that
 269          * eg user_text fields can be used directly.
 270          *
 271          * @param $ns Int the namespace of the article
 272          * @param $title String the unprefixed database key form
 273          * @param $fragment String the link fragment (after the "#")
 274          * @param $interwiki String the interwiki prefix
 275          * @return Title the new object
 276          */
 277         public static function &makeTitle( $ns, $title, $fragment = '', $interwiki = '' ) {
 278                 $t = new Title();
 279                 $t->mInterwiki = $interwiki;
 280                 $t->mFragment = $fragment;
 281                 $t->mNamespace = $ns = intval( $ns );
 282                 $t->mDbkeyform = str_replace( ' ', '_', $title );
 283                 $t->mArticleID = ( $ns >= 0 ) ? -1 : 0;
 284                 $t->mUrlform = wfUrlencode( $t->mDbkeyform );
 285                 $t->mTextform = str_replace( '_', ' ', $title );
 286                 return $t;
 287         }
 288
 289         /**
 290          * Create a new Title from a namespace index and a DB key.
 291          * The parameters will be checked for validity, which is a bit slower
 292          * than makeTitle() but safer for user-provided data.
 293          *
 294          * @param $ns Int the namespace of the article
 295          * @param $title String database key form
 296          * @param $fragment String the link fragment (after the "#")
 297          * @param $interwiki String interwiki prefix
 298          * @return Title the new object, or NULL on an error
 299          */
 300         public static function makeTitleSafe( $ns, $title, $fragment = '', $interwiki = '' ) {
 301                 $t = new Title();
 302                 $t->mDbkeyform = Title::makeName( $ns, $title, $fragment, $interwiki );
 303                 if ( $t->secureAndSplit() ) {
 304                         return $t;
 305                 } else {
 306                         return null;
 307                 }
 308         }
 309
 310         /**
 311          * Create a new Title for the Main Page
 312          *
 313          * @return Title the new object
 314          */
 315         public static function newMainPage() {
 316                 $title = Title::newFromText( wfMsgForContent( 'mainpage' ) );
 317                 // Don't give fatal errors if the message is broken
 318                 if ( !$title ) {
 319                         $title = Title::newFromText( 'Main Page' );
 320                 }
 321                 return $title;
 322         }
 323
 324         /**
 325          * Extract a redirect destination from a string and return the
 326          * Title, or null if the text doesn't contain a valid redirect
 327          * This will only return the very next target, useful for
 328          * the redirect table and other checks that don't need full recursion
 329          *
 330          * @param $text String: Text with possible redirect
 331          * @return Title: The corresponding Title
 332          */
 333         public static function newFromRedirect( $text ) {
 334                 return self::newFromRedirectInternal( $text );
 335         }
 336
 337         /**
 338          * Extract a redirect destination from a string and return the
 339          * Title, or null if the text doesn't contain a valid redirect
 340          * This will recurse down $wgMaxRedirects times or until a non-redirect target is hit
 341          * in order to provide (hopefully) the Title of the final destination instead of another redirect
 342          *
 343          * @param $text String Text with possible redirect
 344          * @return Title
 345          */
 346         public static function newFromRedirectRecurse( $text ) {
 347                 $titles = self::newFromRedirectArray( $text );
 348                 return $titles ? array_pop( $titles ) : null;
 349         }
 350
 351         /**
 352          * Extract a redirect destination from a string and return an
 353          * array of Titles, or null if the text doesn't contain a valid redirect
 354          * The last element in the array is the final destination after all redirects
 355          * have been resolved (up to $wgMaxRedirects times)
 356          *
 357          * @param $text String Text with possible redirect
 358          * @return Array of Titles, with the destination last
 359          */
 360         public static function newFromRedirectArray( $text ) {
 361                 global $wgMaxRedirects;
 362                 $title = self::newFromRedirectInternal( $text );
 363                 if ( is_null( $title ) ) {
 364                         return null;
 365                 }
 366                 // recursive check to follow double redirects
 367                 $recurse = $wgMaxRedirects;
 368                 $titles = array( $title );
 369                 while ( --$recurse > 0 ) {
 370                         if ( $title->isRedirect() ) {
 371                                 $article = new Article( $title, 0 );
 372                                 $newtitle = $article->getRedirectTarget();
 373                         } else {
 374                                 break;
 375                         }
 376                         // Redirects to some special pages are not permitted
 377                         if ( $newtitle instanceOf Title && $newtitle->isValidRedirectTarget() ) {
 378                                 // the new title passes the checks, so make that our current title so that further recursion can be checked
 379                                 $title = $newtitle;
 380                                 $titles[] = $newtitle;
 381                         } else {
 382                                 break;
 383                         }
 384                 }
 385                 return $titles;
 386         }
 387
 388         /**
 389          * Really extract the redirect destination
 390          * Do not call this function directly, use one of the newFromRedirect* functions above
 391          *
 392          * @param $text String Text with possible redirect
 393          * @return Title
 394          */
 395         protected static function newFromRedirectInternal( $text ) {
 396                 global $wgMaxRedirects;
 397                 if ( $wgMaxRedirects < 1 ) {
 398                         //redirects are disabled, so quit early
 399                         return null;
 400                 }
 401                 $redir = MagicWord::get( 'redirect' );
 402                 $text = trim( $text );
 403                 if ( $redir->matchStartAndRemove( $text ) ) {
 404                         // Extract the first link and see if it's usable
 405                         // Ensure that it really does come directly after #REDIRECT
 406                         // Some older redirects included a colon, so don't freak about that!
 407                         $m = array();
 408                         if ( preg_match( '!^\s*:?\s*\[{2}(.*?)(?:\|.*?)?\]{2}!', $text, $m ) ) {
 409                                 // Strip preceding colon used to "escape" categories, etc.
 410                                 // and URL-decode links
 411                                 if ( strpos( $m[1], '%' ) !== false ) {
 412                                         // Match behavior of inline link parsing here;
 413                                         $m[1] = rawurldecode( ltrim( $m[1], ':' ) );
 414                                 }
 415                                 $title = Title::newFromText( $m[1] );
 416                                 // If the title is a redirect to bad special pages or is invalid, return null
 417                                 if ( !$title instanceof Title || !$title->isValidRedirectTarget() ) {
 418                                         return null;
 419                                 }
 420                                 return $title;
 421                         }
 422                 }
 423                 return null;
 424         }
 425
 426 # ----------------------------------------------------------------------------
 427 #       Static functions
 428 # ----------------------------------------------------------------------------
 429
 430         /**
 431          * Get the prefixed DB key associated with an ID
 432          *
 433          * @param $id Int the page_id of the article
 434          * @return Title an object representing the article, or NULL if no such article was found
 435          */
 436         public static function nameOf( $id ) {
 437                 $dbr = wfGetDB( DB_SLAVE );
 438
 439                 $s = $dbr->selectRow(
 440                         'page',
 441                         array( 'page_namespace', 'page_title' ),
 442                         array( 'page_id' => $id ),
 443                         __METHOD__
 444                 );
 445                 if ( $s === false ) {
 446                         return null;
 447                 }
 448
 449                 $n = self::makeName( $s->page_namespace, $s->page_title );
 450                 return $n;
 451         }
 452
 453         /**
 454          * Get a regex character class describing the legal characters in a link
 455          *
 456          * @return String the list of characters, not delimited
 457          */
 458         public static function legalChars() {
 459                 global $wgLegalTitleChars;
 460                 return $wgLegalTitleChars;
 461         }
 462
 463         /**
 464          * Get a string representation of a title suitable for
 465          * including in a search index
 466          *
 467          * @param $ns Int a namespace index
 468          * @param $title String text-form main part
 469          * @return String a stripped-down title string ready for the search index
 470          */
 471         public static function indexTitle( $ns, $title ) {
 472                 global $wgContLang;
 473
 474                 $lc = SearchEngine::legalSearchChars() . '&#;';
 475                 $t = $wgContLang->normalizeForSearch( $title );
 476                 $t = preg_replace( "/[^{$lc}]+/", ' ', $t );
 477                 $t = $wgContLang->lc( $t );
 478
 479                 # Handle 's, s'
 480                 $t = preg_replace( "/([{$lc}]+)'s( |$)/", "\\1 \\1's ", $t );
 481                 $t = preg_replace( "/([{$lc}]+)s'( |$)/", "\\1s ", $t );
 482
 483                 $t = preg_replace( "/\\s+/", ' ', $t );
 484
 485                 if ( $ns == NS_FILE ) {
 486                         $t = preg_replace( "/ (png|gif|jpg|jpeg|ogg)$/", "", $t );
 487                 }
 488                 return trim( $t );
 489         }
 490
 491         /**
 492          * Make a prefixed DB key from a DB key and a namespace index
 493          *
 494          * @param $ns Int numerical representation of the namespace
 495          * @param $title String the DB key form the title
 496          * @param $fragment String The link fragment (after the "#")
 497          * @param $interwiki String The interwiki prefix
 498          * @return String the prefixed form of the title
 499          */
 500         public static function makeName( $ns, $title, $fragment = '', $interwiki = '' ) {
 501                 global $wgContLang;
 502
 503                 $namespace = $wgContLang->getNsText( $ns );
 504                 $name = $namespace == '' ? $title : "$namespace:$title";
 505                 if ( strval( $interwiki ) != '' ) {
 506                         $name = "$interwiki:$name";
 507                 }
 508                 if ( strval( $fragment ) != '' ) {
 509                         $name .= '#' . $fragment;
 510                 }
 511                 return $name;
 512         }
 513
 514         /**
 515          * Determine whether the object refers to a page within
 516          * this project.
 517          *
 518          * @return Bool TRUE if this is an in-project interwiki link or a wikilink, FALSE otherwise
 519          */
 520         public function isLocal() {
 521                 if ( $this->mInterwiki != '' ) {
 522                         return Interwiki::fetch( $this->mInterwiki )->isLocal();
 523                 } else {
 524                         return true;
 525                 }
 526         }
 527
 528         /**
 529          * Determine whether the object refers to a page within
 530          * this project and is transcludable.
 531          *
 532          * @return Bool TRUE if this is transcludable
 533          */
 534         public function isTrans() {
 535                 if ( $this->mInterwiki == '' ) {
 536                         return false;
 537                 }
 538
 539                 return Interwiki::fetch( $this->mInterwiki )->isTranscludable();
 540         }
 541
 542         /**
 543          * Returns the DB name of the distant wiki which owns the object.
 544          *
 545          * @return String the DB name
 546          */
 547         public function getTransWikiID() {
 548                 if ( $this->mInterwiki == '' ) {
 549                         return false;
 550                 }
 551
 552                 return Interwiki::fetch( $this->mInterwiki )->getWikiID();
 553         }
 554
 555         /**
 556          * Escape a text fragment, say from a link, for a URL
 557          *
 558          * @param $fragment string containing a URL or link fragment (after the "#")
 559          * @return String: escaped string
 560          */
 561         static function escapeFragmentForURL( $fragment ) {
 562                 # Note that we don't urlencode the fragment.  urlencoded Unicode
 563                 # fragments appear not to work in IE (at least up to 7) or in at least
 564                 # one version of Opera 9.x.  The W3C validator, for one, doesn't seem
 565                 # to care if they aren't encoded.
 566                 return Sanitizer::escapeId( $fragment, 'noninitial' );
 567         }
 568
 569 # ----------------------------------------------------------------------------
 570 #       Other stuff
 571 # ----------------------------------------------------------------------------
 572
 573         /** Simple accessors */
 574         /**
 575          * Get the text form (spaces not underscores) of the main part
 576          *
 577          * @return String Main part of the title
 578          */
 579         public function getText() { return $this->mTextform; }
 580
 581         /**
 582          * Get the URL-encoded form of the main part
 583          *
 584          * @return String Main part of the title, URL-encoded
 585          */
 586         public function getPartialURL() { return $this->mUrlform; }
 587
 588         /**
 589          * Get the main part with underscores
 590          *
 591          * @return String: Main part of the title, with underscores
 592          */
 593         public function getDBkey() { return $this->mDbkeyform; }
 594
 595         /**
 596          * Get the namespace index, i.e. one of the NS_xxxx constants.
 597          *
 598          * @return Integer: Namespace index
 599          */
 600         public function getNamespace() { return $this->mNamespace; }
 601
 602         /**
 603          * Get the namespace text
 604          *
 605          * @return String: Namespace text
 606          */
 607         public function getNsText() {
 608                 global $wgContLang;
 609
 610                 if ( $this->mInterwiki != '' ) {
 611                         // This probably shouldn't even happen. ohh man, oh yuck.
 612                         // But for interwiki transclusion it sometimes does.
 613                         // Shit. Shit shit shit.
 614                         //
 615                         // Use the canonical namespaces if possible to try to
 616                         // resolve a foreign namespace.
 617                         if ( MWNamespace::exists( $this->mNamespace ) ) {
 618                                 return MWNamespace::getCanonicalName( $this->mNamespace );
 619                         }
 620                 }
 621
 622                 if ( $wgContLang->needsGenderDistinction() &&
 623                                 MWNamespace::hasGenderDistinction( $this->mNamespace ) ) {
 624                         $gender = GenderCache::singleton()->getGenderOf( $this->getText(), __METHOD__ );
 625                         return $wgContLang->getGenderNsText( $this->mNamespace, $gender );
 626                 }
 627
 628                 return $wgContLang->getNsText( $this->mNamespace );
 629         }
 630
 631         /**
 632          * Get the DB key with the initial letter case as specified by the user
 633          *
 634          * @return String DB key
 635          */
 636         function getUserCaseDBKey() {
 637                 return $this->mUserCaseDBKey;
 638         }
 639
 640         /**
 641          * Get the namespace text of the subject (rather than talk) page
 642          *
 643          * @return String Namespace text
 644          */
 645         public function getSubjectNsText() {
 646                 global $wgContLang;
 647                 return $wgContLang->getNsText( MWNamespace::getSubject( $this->mNamespace ) );
 648         }
 649
 650         /**
 651          * Get the namespace text of the talk page
 652          *
 653          * @return String Namespace text
 654          */
 655         public function getTalkNsText() {
 656                 global $wgContLang;
 657                 return( $wgContLang->getNsText( MWNamespace::getTalk( $this->mNamespace ) ) );
 658         }
 659
 660         /**
 661          * Could this title have a corresponding talk page?
 662          *
 663          * @return Bool TRUE or FALSE
 664          */
 665         public function canTalk() {
 666                 return( MWNamespace::canTalk( $this->mNamespace ) );
 667         }
 668
 669         /**
 670          * Get the interwiki prefix (or null string)
 671          *
 672          * @return String Interwiki prefix
 673          */
 674         public function getInterwiki() { return $this->mInterwiki; }
 675
 676         /**
 677          * Get the Title fragment (i.e.\ the bit after the #) in text form
 678          *
 679          * @return String Title fragment
 680          */
 681         public function getFragment() { return $this->mFragment; }
 682
 683         /**
 684          * Get the fragment in URL form, including the "#" character if there is one
 685          * @return String Fragment in URL form
 686          */
 687         public function getFragmentForURL() {
 688                 if ( $this->mFragment == '' ) {
 689                         return '';
 690                 } else {
 691                         return '#' . Title::escapeFragmentForURL( $this->mFragment );
 692                 }
 693         }
 694
 695         /**
 696          * Get the default namespace index, for when there is no namespace
 697          *
 698          * @return Int Default namespace index
 699          */
 700         public function getDefaultNamespace() { return $this->mDefaultNamespace; }
 701
 702         /**
 703          * Get title for search index
 704          *
 705          * @return String a stripped-down title string ready for the
 706          *  search index
 707          */
 708         public function getIndexTitle() {
 709                 return Title::indexTitle( $this->mNamespace, $this->mTextform );
 710         }
 711
 712         /**
 713          * Get the prefixed database key form
 714          *
 715          * @return String the prefixed title, with underscores and
 716          *  any interwiki and namespace prefixes
 717          */
 718         public function getPrefixedDBkey() {
 719                 $s = $this->prefix( $this->mDbkeyform );
 720                 $s = str_replace( ' ', '_', $s );
 721                 return $s;
 722         }
 723
 724         /**
 725          * Get the prefixed title with spaces.
 726          * This is the form usually used for display
 727          *
 728          * @return String the prefixed title, with spaces
 729          */
 730         public function getPrefixedText() {
 731                 if ( empty( $this->mPrefixedText ) ) { // FIXME: bad usage of empty() ?
 732                         $s = $this->prefix( $this->mTextform );
 733                         $s = str_replace( '_', ' ', $s );
 734                         $this->mPrefixedText = $s;
 735                 }
 736                 return $this->mPrefixedText;
 737         }
 738
 739         /**
 740          * Get the prefixed title with spaces, plus any fragment
 741          * (part beginning with '#')
 742          *
 743          * @return String the prefixed title, with spaces and the fragment, including '#'
 744          */
 745         public function getFullText() {
 746                 $text = $this->getPrefixedText();
 747                 if ( $this->mFragment != '' ) {
 748                         $text .= '#' . $this->mFragment;
 749                 }
 750                 return $text;
 751         }
 752
 753         /**
 754          * Get the base name, i.e. the leftmost parts before the /
 755          *
 756          * @return String Base name
 757          */
 758         public function getBaseText() {
 759                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 760                         return $this->getText();
 761                 }
 762
 763                 $parts = explode( '/', $this->getText() );
 764                 # Don't discard the real title if there's no subpage involved
 765                 if ( count( $parts ) > 1 ) {
 766                         unset( $parts[count( $parts ) - 1] );
 767                 }
 768                 return implode( '/', $parts );
 769         }
 770
 771         /**
 772          * Get the lowest-level subpage name, i.e. the rightmost part after /
 773          *
 774          * @return String Subpage name
 775          */
 776         public function getSubpageText() {
 777                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
 778                         return( $this->mTextform );
 779                 }
 780                 $parts = explode( '/', $this->mTextform );
 781                 return( $parts[count( $parts ) - 1] );
 782         }
 783
 784         /**
 785          * Get a URL-encoded form of the subpage text
 786          *
 787          * @return String URL-encoded subpage name
 788          */
 789         public function getSubpageUrlForm() {
 790                 $text = $this->getSubpageText();
 791                 $text = wfUrlencode( str_replace( ' ', '_', $text ) );
 792                 return( $text );
 793         }
 794
 795         /**
 796          * Get a URL-encoded title (not an actual URL) including interwiki
 797          *
 798          * @return String the URL-encoded form
 799          */
 800         public function getPrefixedURL() {
 801                 $s = $this->prefix( $this->mDbkeyform );
 802                 $s = wfUrlencode( str_replace( ' ', '_', $s ) );
 803                 return $s;
 804         }
 805
 806         /**
 807          * Get a real URL referring to this title, with interwiki link and
 808          * fragment
 809          *
 810          * @param $query \twotypes{\string,\array} an optional query string, not used for interwiki
 811          *   links. Can be specified as an associative array as well, e.g.,
 812          *   array( 'action' => 'edit' ) (keys and values will be URL-escaped).
 813          * @param $variant String language variant of url (for sr, zh..)
 814          * @return String the URL
 815          */
 816         public function getFullURL( $query = '', $variant = false ) {
 817                 global $wgServer, $wgRequest;
 818
 819                 if ( is_array( $query ) ) {
 820                         $query = wfArrayToCGI( $query );
 821                 }
 822
 823                 $interwiki = Interwiki::fetch( $this->mInterwiki );
 824                 if ( !$interwiki ) {
 825                         $url = $this->getLocalURL( $query, $variant );
 826
 827                         // Ugly quick hack to avoid duplicate prefixes (bug 4571 etc)
 828                         // Correct fix would be to move the prepending elsewhere.
 829                         if ( $wgRequest->getVal( 'action' ) != 'render' ) {
 830                                 $url = $wgServer . $url;
 831                         }
 832                 } else {
 833                         $baseUrl = $interwiki->getURL();
 834
 835                         $namespace = wfUrlencode( $this->getNsText() );
 836                         if ( $namespace != '' ) {
 837                                 # Can this actually happen? Interwikis shouldn't be parsed.
 838                                 # Yes! It can in interwiki transclusion. But... it probably shouldn't.
 839                                 $namespace .= ':';
 840                         }
 841                         $url = str_replace( '$1', $namespace . $this->mUrlform, $baseUrl );
 842                         $url = wfAppendQuery( $url, $query );
 843                 }
 844
 845                 # Finally, add the fragment.
 846                 $url .= $this->getFragmentForURL();
 847
 848                 wfRunHooks( 'GetFullURL', array( &$this, &$url, $query ) );
 849                 return $url;
 850         }
 851
 852         /**
 853          * Get a URL with no fragment or server name.  If this page is generated
 854          * with action=render, $wgServer is prepended.
 855          *
 856          * @param $query Mixed: an optional query string; if not specified,
 857          *   $wgArticlePath will be used.  Can be specified as an associative array
 858          *   as well, e.g., array( 'action' => 'edit' ) (keys and values will be
 859          *   URL-escaped).
 860          * @param $variant String language variant of url (for sr, zh..)
 861          * @return String the URL
 862          */
 863         public function getLocalURL( $query = '', $variant = false ) {
 864                 global $wgArticlePath, $wgScript, $wgServer, $wgRequest;
 865                 global $wgVariantArticlePath, $wgContLang;
 866
 867                 if ( is_array( $query ) ) {
 868                         $query = wfArrayToCGI( $query );
 869                 }
 870
 871                 if ( $this->isExternal() ) {
 872                         $url = $this->getFullURL();
 873                         if ( $query ) {
 874                                 // This is currently only used for edit section links in the
 875                                 // context of interwiki transclusion. In theory we should
 876                                 // append the query to the end of any existing query string,
 877                                 // but interwiki transclusion is already broken in that case.
 878                                 $url .= "?$query";
 879                         }
 880                 } else {
 881                         $dbkey = wfUrlencode( $this->getPrefixedDBkey() );
 882                         if ( $query == '' ) {
 883                                 if ( $variant != false && $wgContLang->hasVariants() ) {
 884                                         if ( !$wgVariantArticlePath ) {
 885                                                 $variantArticlePath =  "$wgScript?title=$1&variant=$2"; // default
 886                                         } else {
 887                                                 $variantArticlePath = $wgVariantArticlePath;
 888                                         }
 889                                         $url = str_replace( '$2', urlencode( $variant ), $variantArticlePath );
 890                                         $url = str_replace( '$1', $dbkey, $url  );
 891                                 } else {
 892                                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 893                                 }
 894                         } else {
 895                                 $url = false;
 896
 897                                 global $wgActionPaths;
 898                                 if( !empty( $wgActionPaths ) ) {
 899                                         $url = Title::resolveActionPath( $dbkey, $query );
 900                                 }
 901
 902                                 if ( $url === false ) {
 903                                         if ( $query == '-' ) {
 904                                                 $query = '';
 905                                         }
 906                                         #$url = "{$wgScript}?title={$dbkey}&{$query}";
 907                                         # forge a nice URL (ex: /wiki/Special:Foo?q=1&r=2 )
 908                                         $baseurl = str_replace( '$1', $dbkey, $wgArticlePath );
 909                                         $url = wfAppendQuery( $baseurl, $query );
 910                                 }
 911                         }
 912
 913                         // FIXME: this causes breakage in various places when we
 914                         // actually expected a local URL and end up with dupe prefixes.
 915                         if ( $wgRequest->getVal( 'action' ) == 'render' ) {
 916                                 $url = $wgServer . $url;
 917                         }
 918                 }
 919                 wfRunHooks( 'GetLocalURL', array( &$this, &$url, $query ) );
 920                 return $url;
 921         }
 922
 923         /**
 924          * Helper for getLocalUrl() to handles $wgActionPaths
 925          *
 926          * @param $dbkey string Title in database key format
 927          * @param $query string request parameters in CGI format (p=1&q=2&..)
 928          * @return Url resolved or boolean false
 929          */
 930         private static function resolveActionPath( $dbkey, $query ) {
 931                 $url = '';
 932
 933                 # query parameters are easier to handle using an array:
 934                 $queryArray = wfCGIToArray( $query );
 935
 936                 global $wgActionPaths;
 937                 if( !array_key_exists( 'action', $queryArray ) ) {
 938                         // Makes the default action 'view' and points to $wgArticlePath
 939                         // FIXME: this should be handled in Setup or Wiki!
 940                         global $wgArticlePath;
 941                         $url = str_replace( '$1', $dbkey, $wgArticlePath );
 942                 } elseif( isset( $wgActionPaths[$queryArray['action']] ) ) {
 943                         $url = str_replace( '$1', $dbkey, $wgActionPaths[$queryArray['action']] );
 944                 } else {
 945                         # No path found
 946                         return false;
 947                 }
 948
 949                 # No need to append the action since we have embed it in the path
 950                 unset( $queryArray['action'] );
 951                 $url = wfAppendQuery( $url, wfArrayToCGI( $queryArray ) );
 952                 return $url;
 953         }
 954
 955         /**
 956          * Get a URL that's the simplest URL that will be valid to link, locally,
 957          * to the current Title.  It includes the fragment, but does not include
 958          * the server unless action=render is used (or the link is external).  If
 959          * there's a fragment but the prefixed text is empty, we just return a link
 960          * to the fragment.
 961          *
 962          * The result obviously should not be URL-escaped, but does need to be
 963          * HTML-escaped if it's being output in HTML.
 964          *
 965          * @param $query Array of Strings An associative array of key => value pairs for the
 966          *   query string.  Keys and values will be escaped.
 967          * @param $variant String language variant of URL (for sr, zh..).  Ignored
 968          *   for external links.  Default is "false" (same variant as current page,
 969          *   for anonymous users).
 970          * @return String the URL
 971          */
 972         public function getLinkUrl( $query = array(), $variant = false ) {
 973                 wfProfileIn( __METHOD__ );
 974                 if ( $this->isExternal() ) {
 975                         $ret = $this->getFullURL( $query );
 976                 } elseif ( $this->getPrefixedText() === '' && $this->getFragment() !== '' ) {
 977                         $ret = $this->getFragmentForURL();
 978                 } else {
 979                         $ret = $this->getLocalURL( $query, $variant ) . $this->getFragmentForURL();
 980                 }
 981                 wfProfileOut( __METHOD__ );
 982                 return $ret;
 983         }
 984
 985         /**
 986          * Get an HTML-escaped version of the URL form, suitable for
 987          * using in a link, without a server name or fragment
 988          *
 989          * @param $query String an optional query string
 990          * @return String the URL
 991          */
 992         public function escapeLocalURL( $query = '' ) {
 993                 return htmlspecialchars( $this->getLocalURL( $query ) );
 994         }
 995
 996         /**
 997          * Get an HTML-escaped version of the URL form, suitable for
 998          * using in a link, including the server name and fragment
 999          *
1000          * @param $query String an optional query string
1001          * @return String the URL
1002          */
1003         public function escapeFullURL( $query = '' ) {
1004                 return htmlspecialchars( $this->getFullURL( $query ) );
1005         }
1006
1007         /**
1008          * Get the URL form for an internal link.
1009          * - Used in various Squid-related code, in case we have a different
1010          * internal hostname for the server from the exposed one.
1011          *
1012          * @param $query String an optional query string
1013          * @param $variant String language variant of url (for sr, zh..)
1014          * @return String the URL
1015          */
1016         public function getInternalURL( $query = '', $variant = false ) {
1017                 global $wgInternalServer, $wgServer;
1018                 $server = $wgInternalServer !== false ? $wgInternalServer : $wgServer;
1019                 $url = $server . $this->getLocalURL( $query, $variant );
1020                 wfRunHooks( 'GetInternalURL', array( &$this, &$url, $query ) );
1021                 return $url;
1022         }
1023
1024         /**
1025          * Get the edit URL for this Title
1026          *
1027          * @return String the URL, or a null string if this is an
1028          *  interwiki link
1029          */
1030         public function getEditURL() {
1031                 if ( $this->mInterwiki != '' ) {
1032                         return '';
1033                 }
1034                 $s = $this->getLocalURL( 'action=edit' );
1035
1036                 return $s;
1037         }
1038
1039         /**
1040          * Get the HTML-escaped displayable text form.
1041          * Used for the title field in <a> tags.
1042          *
1043          * @return String the text, including any prefixes
1044          */
1045         public function getEscapedText() {
1046                 return htmlspecialchars( $this->getPrefixedText() );
1047         }
1048
1049         /**
1050          * Is this Title interwiki?
1051          *
1052          * @return Bool
1053          */
1054         public function isExternal() {
1055                 return ( $this->mInterwiki != '' );
1056         }
1057
1058         /**
1059          * Is this page "semi-protected" - the *only* protection is autoconfirm?
1060          *
1061          * @param $action String Action to check (default: edit)
1062          * @return Bool
1063          */
1064         public function isSemiProtected( $action = 'edit' ) {
1065                 if ( $this->exists() ) {
1066                         $restrictions = $this->getRestrictions( $action );
1067                         if ( count( $restrictions ) > 0 ) {
1068                                 foreach ( $restrictions as $restriction ) {
1069                                         if ( strtolower( $restriction ) != 'autoconfirmed' ) {
1070                                                 return false;
1071                                         }
1072                                 }
1073                         } else {
1074                                 # Not protected
1075                                 return false;
1076                         }
1077                         return true;
1078                 } else {
1079                         # If it doesn't exist, it can't be protected
1080                         return false;
1081                 }
1082         }
1083
1084         /**
1085          * Does the title correspond to a protected article?
1086          *
1087          * @param $action String the action the page is protected from,
1088          * by default checks all actions.
1089          * @return Bool
1090          */
1091         public function isProtected( $action = '' ) {
1092                 global $wgRestrictionLevels;
1093
1094                 $restrictionTypes = $this->getRestrictionTypes();
1095
1096                 # Special pages have inherent protection
1097                 if( $this->getNamespace() == NS_SPECIAL ) {
1098                         return true;
1099                 }
1100
1101                 # Check regular protection levels
1102                 foreach ( $restrictionTypes as $type ) {
1103                         if ( $action == $type || $action == '' ) {
1104                                 $r = $this->getRestrictions( $type );
1105                                 foreach ( $wgRestrictionLevels as $level ) {
1106                                         if ( in_array( $level, $r ) && $level != '' ) {
1107                                                 return true;
1108                                         }
1109                                 }
1110                         }
1111                 }
1112
1113                 return false;
1114         }
1115
1116         /**
1117          * Is this a conversion table for the LanguageConverter?
1118          *
1119          * @return Bool
1120          */
1121         public function isConversionTable() {
1122                 if(
1123                         $this->getNamespace() == NS_MEDIAWIKI &&
1124                         strpos( $this->getText(), 'Conversiontable' ) !== false
1125                 )
1126                 {
1127                         return true;
1128                 }
1129
1130                 return false;
1131         }
1132
1133         /**
1134          * Is $wgUser watching this page?
1135          *
1136          * @return Bool
1137          */
1138         public function userIsWatching() {
1139                 global $wgUser;
1140
1141                 if ( is_null( $this->mWatched ) ) {
1142                         if ( NS_SPECIAL == $this->mNamespace || !$wgUser->isLoggedIn() ) {
1143                                 $this->mWatched = false;
1144                         } else {
1145                                 $this->mWatched = $wgUser->isWatched( $this );
1146                         }
1147                 }
1148                 return $this->mWatched;
1149         }
1150
1151         /**
1152          * Can $wgUser perform $action on this page?
1153          * This skips potentially expensive cascading permission checks
1154          * as well as avoids expensive error formatting
1155          *
1156          * Suitable for use for nonessential UI controls in common cases, but
1157          * _not_ for functional access control.
1158          *
1159          * May provide false positives, but should never provide a false negative.
1160          *
1161          * @param $action String action that permission needs to be checked for
1162          * @return Bool
1163          */
1164         public function quickUserCan( $action ) {
1165                 return $this->userCan( $action, false );
1166         }
1167
1168         /**
1169          * Determines if $user is unable to edit this page because it has been protected
1170          * by $wgNamespaceProtection.
1171          *
1172          * @param $user User object, $wgUser will be used if not passed
1173          * @return Bool
1174          */
1175         public function isNamespaceProtected( User $user = null ) {
1176                 global $wgNamespaceProtection;
1177
1178                 if ( $user === null ) {
1179                         global $wgUser;
1180                         $user = $wgUser;
1181                 }
1182
1183                 if ( isset( $wgNamespaceProtection[$this->mNamespace] ) ) {
1184                         foreach ( (array)$wgNamespaceProtection[$this->mNamespace] as $right ) {
1185                                 if ( $right != '' && !$user->isAllowed( $right ) ) {
1186                                         return true;
1187                                 }
1188                         }
1189                 }
1190                 return false;
1191         }
1192
1193         /**
1194          * Can $wgUser perform $action on this page?
1195          *
1196          * @param $action String action that permission needs to be checked for
1197          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1198          * @return Bool
1199          */
1200         public function userCan( $action, $doExpensiveQueries = true ) {
1201                 global $wgUser;
1202                 return ( $this->getUserPermissionsErrorsInternal( $action, $wgUser, $doExpensiveQueries, true ) === array() );
1203         }
1204
1205         /**
1206          * Can $user perform $action on this page?
1207          *
1208          * FIXME: This *does not* check throttles (User::pingLimiter()).
1209          *
1210          * @param $action String action that permission needs to be checked for
1211          * @param $user User to check
1212          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1213          * @param $ignoreErrors Array of Strings Set this to a list of message keys whose corresponding errors may be ignored.
1214          * @return Array of arguments to wfMsg to explain permissions problems.
1215          */
1216         public function getUserPermissionsErrors( $action, $user, $doExpensiveQueries = true, $ignoreErrors = array() ) {
1217                 $errors = $this->getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries );
1218
1219                 // Remove the errors being ignored.
1220                 foreach ( $errors as $index => $error ) {
1221                         $error_key = is_array( $error ) ? $error[0] : $error;
1222
1223                         if ( in_array( $error_key, $ignoreErrors ) ) {
1224                                 unset( $errors[$index] );
1225                         }
1226                 }
1227
1228                 return $errors;
1229         }
1230
1231         /**
1232          * Permissions checks that fail most often, and which are easiest to test.
1233          *
1234          * @param $action String the action to check
1235          * @param $user User user to check
1236          * @param $errors Array list of current errors
1237          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1238          * @param $short Boolean short circuit on first error
1239          *
1240          * @return Array list of errors
1241          */
1242         private function checkQuickPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1243                 if ( $action == 'create' ) {
1244                         if ( ( $this->isTalkPage() && !$user->isAllowed( 'createtalk' ) ) ||
1245                                  ( !$this->isTalkPage() && !$user->isAllowed( 'createpage' ) ) ) {
1246                                 $errors[] = $user->isAnon() ? array( 'nocreatetext' ) : array( 'nocreate-loggedin' );
1247                         }
1248                 } elseif ( $action == 'move' ) {
1249                         if ( !$user->isAllowed( 'move-rootuserpages' )
1250                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1251                                 // Show user page-specific message only if the user can move other pages
1252                                 $errors[] = array( 'cant-move-user-page' );
1253                         }
1254
1255                         // Check if user is allowed to move files if it's a file
1256                         if ( $this->mNamespace == NS_FILE && !$user->isAllowed( 'movefile' ) ) {
1257                                 $errors[] = array( 'movenotallowedfile' );
1258                         }
1259
1260                         if ( !$user->isAllowed( 'move' ) ) {
1261                                 // User can't move anything
1262                                 global $wgGroupPermissions;
1263                                 $userCanMove = false;
1264                                 if ( isset( $wgGroupPermissions['user']['move'] ) ) {
1265                                         $userCanMove = $wgGroupPermissions['user']['move'];
1266                                 }
1267                                 $autoconfirmedCanMove = false;
1268                                 if ( isset( $wgGroupPermissions['autoconfirmed']['move'] ) ) {
1269                                         $autoconfirmedCanMove = $wgGroupPermissions['autoconfirmed']['move'];
1270                                 }
1271                                 if ( $user->isAnon() && ( $userCanMove || $autoconfirmedCanMove ) ) {
1272                                         // custom message if logged-in users without any special rights can move
1273                                         $errors[] = array( 'movenologintext' );
1274                                 } else {
1275                                         $errors[] = array( 'movenotallowed' );
1276                                 }
1277                         }
1278                 } elseif ( $action == 'move-target' ) {
1279                         if ( !$user->isAllowed( 'move' ) ) {
1280                                 // User can't move anything
1281                                 $errors[] = array( 'movenotallowed' );
1282                         } elseif ( !$user->isAllowed( 'move-rootuserpages' )
1283                                         && $this->mNamespace == NS_USER && !$this->isSubpage() ) {
1284                                 // Show user page-specific message only if the user can move other pages
1285                                 $errors[] = array( 'cant-move-to-user-page' );
1286                         }
1287                 } elseif ( !$user->isAllowed( $action ) ) {
1288                         // We avoid expensive display logic for quickUserCan's and such
1289                         $groups = false;
1290                         if ( !$short ) {
1291                                 $groups = array_map( array( 'User', 'makeGroupLinkWiki' ),
1292                                         User::getGroupsWithPermission( $action ) );
1293                         }
1294
1295                         if ( $groups ) {
1296                                 global $wgLang;
1297                                 $return = array(
1298                                         'badaccess-groups',
1299                                         $wgLang->commaList( $groups ),
1300                                         count( $groups )
1301                                 );
1302                         } else {
1303                                 $return = array( 'badaccess-group0' );
1304                         }
1305                         $errors[] = $return;
1306                 }
1307
1308                 return $errors;
1309         }
1310
1311         /**
1312          * Add the resulting error code to the errors array
1313          *
1314          * @param $errors Array list of current errors
1315          * @param $result Mixed result of errors
1316          *
1317          * @return Array list of errors
1318          */
1319         private function resultToError( $errors, $result ) {
1320                 if ( is_array( $result ) && count( $result ) && !is_array( $result[0] ) ) {
1321                         // A single array representing an error
1322                         $errors[] = $result;
1323                 } else if ( is_array( $result ) && is_array( $result[0] ) ) {
1324                         // A nested array representing multiple errors
1325                         $errors = array_merge( $errors, $result );
1326                 } else if ( $result !== '' && is_string( $result ) ) {
1327                         // A string representing a message-id
1328                         $errors[] = array( $result );
1329                 } else if ( $result === false ) {
1330                         // a generic "We don't want them to do that"
1331                         $errors[] = array( 'badaccess-group0' );
1332                 }
1333                 return $errors;
1334         }
1335
1336         /**
1337          * Check various permission hooks
1338          *
1339          * @param $action String the action to check
1340          * @param $user User user to check
1341          * @param $errors Array list of current errors
1342          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1343          * @param $short Boolean short circuit on first error
1344          *
1345          * @return Array list of errors
1346          */
1347         private function checkPermissionHooks( $action, $user, $errors, $doExpensiveQueries, $short ) {
1348                 // Use getUserPermissionsErrors instead
1349                 $result = '';
1350                 if ( !wfRunHooks( 'userCan', array( &$this, &$user, $action, &$result ) ) ) {
1351                         return $result ? array() : array( array( 'badaccess-group0' ) );
1352                 }
1353                 // Check getUserPermissionsErrors hook
1354                 if ( !wfRunHooks( 'getUserPermissionsErrors', array( &$this, &$user, $action, &$result ) ) ) {
1355                         $errors = $this->resultToError( $errors, $result );
1356                 }
1357                 // Check getUserPermissionsErrorsExpensive hook
1358                 if ( $doExpensiveQueries && !( $short && count( $errors ) > 0 ) &&
1359                          !wfRunHooks( 'getUserPermissionsErrorsExpensive', array( &$this, &$user, $action, &$result ) ) ) {
1360                         $errors = $this->resultToError( $errors, $result );
1361                 }
1362
1363                 return $errors;
1364         }
1365
1366         /**
1367          * Check permissions on special pages & namespaces
1368          *
1369          * @param $action String the action to check
1370          * @param $user User user to check
1371          * @param $errors Array list of current errors
1372          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1373          * @param $short Boolean short circuit on first error
1374          *
1375          * @return Array list of errors
1376          */
1377         private function checkSpecialsAndNSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1378                 # Only 'createaccount' and 'execute' can be performed on
1379                 # special pages, which don't actually exist in the DB.
1380                 $specialOKActions = array( 'createaccount', 'execute' );
1381                 if ( NS_SPECIAL == $this->mNamespace && !in_array( $action, $specialOKActions ) ) {
1382                         $errors[] = array( 'ns-specialprotected' );
1383                 }
1384
1385                 # Check $wgNamespaceProtection for restricted namespaces
1386                 if ( $this->isNamespaceProtected( $user ) ) {
1387                         $ns = $this->mNamespace == NS_MAIN ?
1388                                 wfMsg( 'nstab-main' ) : $this->getNsText();
1389                         $errors[] = $this->mNamespace == NS_MEDIAWIKI ?
1390                                 array( 'protectedinterface' ) : array( 'namespaceprotected',  $ns );
1391                 }
1392
1393                 return $errors;
1394         }
1395
1396         /**
1397          * Check CSS/JS sub-page permissions
1398          *
1399          * @param $action String the action to check
1400          * @param $user User user to check
1401          * @param $errors Array list of current errors
1402          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1403          * @param $short Boolean short circuit on first error
1404          *
1405          * @return Array list of errors
1406          */
1407         private function checkCSSandJSPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1408                 # Protect css/js subpages of user pages
1409                 # XXX: this might be better using restrictions
1410                 # XXX: Find a way to work around the php bug that prevents using $this->userCanEditCssSubpage()
1411                 #      and $this->userCanEditJsSubpage() from working
1412                 # XXX: right 'editusercssjs' is deprecated, for backward compatibility only
1413                 if ( $action != 'patrol' && !$user->isAllowed( 'editusercssjs' )
1414                                 && !preg_match( '/^' . preg_quote( $user->getName(), '/' ) . '\//', $this->mTextform ) ) {
1415                         if ( $this->isCssSubpage() && !$user->isAllowed( 'editusercss' ) ) {
1416                                 $errors[] = array( 'customcssjsprotected' );
1417                         } else if ( $this->isJsSubpage() && !$user->isAllowed( 'edituserjs' ) ) {
1418                                 $errors[] = array( 'customcssjsprotected' );
1419                         }
1420                 }
1421
1422                 return $errors;
1423         }
1424
1425         /**
1426          * Check against page_restrictions table requirements on this
1427          * page. The user must possess all required rights for this
1428          * action.
1429          *
1430          * @param $action String the action to check
1431          * @param $user User user to check
1432          * @param $errors Array list of current errors
1433          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1434          * @param $short Boolean short circuit on first error
1435          *
1436          * @return Array list of errors
1437          */
1438         private function checkPageRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1439                 foreach ( $this->getRestrictions( $action ) as $right ) {
1440                         // Backwards compatibility, rewrite sysop -> protect
1441                         if ( $right == 'sysop' ) {
1442                                 $right = 'protect';
1443                         }
1444                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1445                                 // Users with 'editprotected' permission can edit protected pages
1446                                 if ( $action == 'edit' && $user->isAllowed( 'editprotected' ) ) {
1447                                         // Users with 'editprotected' permission cannot edit protected pages
1448                                         // with cascading option turned on.
1449                                         if ( $this->mCascadeRestriction ) {
1450                                                 $errors[] = array( 'protectedpagetext', $right );
1451                                         }
1452                                 } else {
1453                                         $errors[] = array( 'protectedpagetext', $right );
1454                                 }
1455                         }
1456                 }
1457
1458                 return $errors;
1459         }
1460
1461         /**
1462          * Check restrictions on cascading pages.
1463          *
1464          * @param $action String the action to check
1465          * @param $user User to check
1466          * @param $errors Array list of current errors
1467          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1468          * @param $short Boolean short circuit on first error
1469          *
1470          * @return Array list of errors
1471          */
1472         private function checkCascadingSourcesRestrictions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1473                 if ( $doExpensiveQueries && !$this->isCssJsSubpage() ) {
1474                         # We /could/ use the protection level on the source page, but it's
1475                         # fairly ugly as we have to establish a precedence hierarchy for pages
1476                         # included by multiple cascade-protected pages. So just restrict
1477                         # it to people with 'protect' permission, as they could remove the
1478                         # protection anyway.
1479                         list( $cascadingSources, $restrictions ) = $this->getCascadeProtectionSources();
1480                         # Cascading protection depends on more than this page...
1481                         # Several cascading protected pages may include this page...
1482                         # Check each cascading level
1483                         # This is only for protection restrictions, not for all actions
1484                         if ( isset( $restrictions[$action] ) ) {
1485                                 foreach ( $restrictions[$action] as $right ) {
1486                                         $right = ( $right == 'sysop' ) ? 'protect' : $right;
1487                                         if ( $right != '' && !$user->isAllowed( $right ) ) {
1488                                                 $pages = '';
1489                                                 foreach ( $cascadingSources as $page )
1490                                                         $pages .= '* [[:' . $page->getPrefixedText() . "]]\n";
1491                                                 $errors[] = array( 'cascadeprotected', count( $cascadingSources ), $pages );
1492                                         }
1493                                 }
1494                         }
1495                 }
1496
1497                 return $errors;
1498         }
1499
1500         /**
1501          * Check action permissions not already checked in checkQuickPermissions
1502          *
1503          * @param $action String the action to check
1504          * @param $user User to check
1505          * @param $errors Array list of current errors
1506          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1507          * @param $short Boolean short circuit on first error
1508          *
1509          * @return Array list of errors
1510          */
1511         private function checkActionPermissions( $action, $user, $errors, $doExpensiveQueries, $short ) {
1512                 if ( $action == 'protect' ) {
1513                         if ( $this->getUserPermissionsErrors( 'edit', $user ) != array() ) {
1514                                 // If they can't edit, they shouldn't protect.
1515                                 $errors[] = array( 'protect-cantedit' );
1516                         }
1517                 } elseif ( $action == 'create' ) {
1518                         $title_protection = $this->getTitleProtection();
1519                         if( $title_protection ) {
1520                                 if( $title_protection['pt_create_perm'] == 'sysop' ) {
1521                                         $title_protection['pt_create_perm'] = 'protect'; // B/C
1522                                 }
1523                                 if( $title_protection['pt_create_perm'] == '' || !$user->isAllowed( $title_protection['pt_create_perm'] ) ) {
1524                                         $errors[] = array( 'titleprotected', User::whoIs( $title_protection['pt_user'] ), $title_protection['pt_reason'] );
1525                                 }
1526                         }
1527                 } elseif ( $action == 'move' ) {
1528                         // Check for immobile pages
1529                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1530                                 // Specific message for this case
1531                                 $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
1532                         } elseif ( !$this->isMovable() ) {
1533                                 // Less specific message for rarer cases
1534                                 $errors[] = array( 'immobile-page' );
1535                         }
1536                 } elseif ( $action == 'move-target' ) {
1537                         if ( !MWNamespace::isMovable( $this->mNamespace ) ) {
1538                                 $errors[] = array( 'immobile-target-namespace', $this->getNsText() );
1539                         } elseif ( !$this->isMovable() ) {
1540                                 $errors[] = array( 'immobile-target-page' );
1541                         }
1542                 }
1543                 return $errors;
1544         }
1545
1546         /**
1547          * Check that the user isn't blocked from editting.
1548          *
1549          * @param $action String the action to check
1550          * @param $user User to check
1551          * @param $errors Array list of current errors
1552          * @param $doExpensiveQueries Boolean whether or not to perform expensive queries
1553          * @param $short Boolean short circuit on first error
1554          *
1555          * @return Array list of errors
1556          */
1557         private function checkUserBlock( $action, $user, $errors, $doExpensiveQueries, $short ) {
1558                 if( $short && count( $errors ) > 0 ) {
1559                         return $errors;
1560                 }
1561
1562                 global $wgContLang, $wgLang, $wgEmailConfirmToEdit;
1563
1564                 if ( $wgEmailConfirmToEdit && !$user->isEmailConfirmed() && $action != 'createaccount' ) {
1565                         $errors[] = array( 'confirmedittext' );
1566                 }
1567
1568                 // Edit blocks should not affect reading. Account creation blocks handled at userlogin.
1569                 if ( $action != 'read' && $action != 'createaccount' && $user->isBlockedFrom( $this ) ) {
1570                         $block = $user->mBlock;
1571
1572                         // This is from OutputPage::blockedPage
1573                         // Copied at r23888 by werdna
1574
1575                         $id = $user->blockedBy();
1576                         $reason = $user->blockedFor();
1577                         if ( $reason == '' ) {
1578                                 $reason = wfMsg( 'blockednoreason' );
1579                         }
1580                         $ip = wfGetIP();
1581
1582                         if ( is_numeric( $id ) ) {
1583                                 $name = User::whoIs( $id );
1584                         } else {
1585                                 $name = $id;
1586                         }
1587
1588                         $link = '[[' . $wgContLang->getNsText( NS_USER ) . ":{$name}|{$name}]]";
1589                         $blockid = $block->mId;
1590                         $blockExpiry = $user->mBlock->mExpiry;
1591                         $blockTimestamp = $wgLang->timeanddate( wfTimestamp( TS_MW, $user->mBlock->mTimestamp ), true );
1592                         if ( $blockExpiry == 'infinity' ) {
1593                                 $blockExpiry = wfMessage( 'infiniteblock' );
1594                         } else {
1595                                 $blockExpiry = $wgLang->timeanddate( wfTimestamp( TS_MW, $blockExpiry ), true );
1596                         }
1597
1598                         $intended = $user->mBlock->mAddress;
1599
1600                         $errors[] = array( ( $block->mAuto ? 'autoblockedtext' : 'blockedtext' ), $link, $reason, $ip, $name,
1601                                 $blockid, $blockExpiry, $intended, $blockTimestamp );
1602                 }
1603
1604                 return $errors;
1605         }
1606
1607         /**
1608          * Can $user perform $action on this page? This is an internal function,
1609          * which checks ONLY that previously checked by userCan (i.e. it leaves out
1610          * checks on wfReadOnly() and blocks)
1611          *
1612          * @param $action String action that permission needs to be checked for
1613          * @param $user User to check
1614          * @param $doExpensiveQueries Bool Set this to false to avoid doing unnecessary queries.
1615          * @param $short Bool Set this to true to stop after the first permission error.
1616          * @return Array of arrays of the arguments to wfMsg to explain permissions problems.
1617          */
1618         protected function getUserPermissionsErrorsInternal( $action, $user, $doExpensiveQueries = true, $short = false ) {
1619                 wfProfileIn( __METHOD__ );
1620
1621                 $errors = array();
1622                 $checks = array(
1623                         'checkQuickPermissions',
1624                         'checkPermissionHooks',
1625                         'checkSpecialsAndNSPermissions',
1626                         'checkCSSandJSPermissions',
1627                         'checkPageRestrictions',
1628                         'checkCascadingSourcesRestrictions',
1629                         'checkActionPermissions',
1630                         'checkUserBlock'
1631                 );
1632
1633                 while( count( $checks ) > 0 &&
1634                            !( $short && count( $errors ) > 0 ) ) {
1635                         $method = array_shift( $checks );
1636                         $errors = $this->$method( $action, $user, $errors, $doExpensiveQueries, $short );
1637                 }
1638
1639                 wfProfileOut( __METHOD__ );
1640                 return $errors;
1641         }
1642
1643         /**
1644          * Is this title subject to title protection?
1645          * Title protection is the one applied against creation of such title.
1646          *
1647          * @return Mixed An associative array representing any existent title
1648          *   protection, or false if there's none.
1649          */
1650         private function getTitleProtection() {
1651                 // Can't protect pages in special namespaces
1652                 if ( $this->getNamespace() < 0 ) {
1653                         return false;
1654                 }
1655
1656                 // Can't protect pages that exist.
1657                 if ( $this->exists() ) {
1658                         return false;
1659                 }
1660
1661                 if ( !isset( $this->mTitleProtection ) ) {
1662                         $dbr = wfGetDB( DB_SLAVE );
1663                         $res = $dbr->select( 'protected_titles', '*',
1664                                 array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1665                                 __METHOD__ );
1666
1667                         // fetchRow returns false if there are no rows.
1668                         $this->mTitleProtection = $dbr->fetchRow( $res );
1669                 }
1670                 return $this->mTitleProtection;
1671         }
1672
1673         /**
1674          * Update the title protection status
1675          *
1676          * @param $create_perm String Permission required for creation
1677          * @param $reason String Reason for protection
1678          * @param $expiry String Expiry timestamp
1679          * @return boolean true
1680          */
1681         public function updateTitleProtection( $create_perm, $reason, $expiry ) {
1682                 global $wgUser, $wgContLang;
1683
1684                 if ( $create_perm == implode( ',', $this->getRestrictions( 'create' ) )
1685                         && $expiry == $this->mRestrictionsExpiry['create'] ) {
1686                         // No change
1687                         return true;
1688                 }
1689
1690                 list ( $namespace, $title ) = array( $this->getNamespace(), $this->getDBkey() );
1691
1692                 $dbw = wfGetDB( DB_MASTER );
1693
1694                 $encodedExpiry = $dbw->encodeExpiry( $expiry );
1695
1696                 $expiry_description = '';
1697                 if ( $encodedExpiry != $dbw->getInfinity() ) {
1698                         $expiry_description = ' (' . wfMsgForContent( 'protect-expiring', $wgContLang->timeanddate( $expiry ),
1699                                 $wgContLang->date( $expiry ) , $wgContLang->time( $expiry ) ) . ')';
1700                 } else {
1701                         $expiry_description .= ' (' . wfMsgForContent( 'protect-expiry-indefinite' ) . ')';
1702                 }
1703
1704                 # Update protection table
1705                 if ( $create_perm != '' ) {
1706                         $this->mTitleProtection = array(
1707                                         'pt_namespace' => $namespace,
1708                                         'pt_title' => $title,
1709                                         'pt_create_perm' => $create_perm,
1710                                         'pt_timestamp' => $dbw->encodeExpiry( wfTimestampNow() ),
1711                                         'pt_expiry' => $encodedExpiry,
1712                                         'pt_user' => $wgUser->getId(),
1713                                         'pt_reason' => $reason,
1714                                 );
1715                         $dbw->replace( 'protected_titles', array( array( 'pt_namespace', 'pt_title' ) ),
1716                                 $this->mTitleProtection, __METHOD__     );
1717                 } else {
1718                         $dbw->delete( 'protected_titles', array( 'pt_namespace' => $namespace,
1719                                 'pt_title' => $title ), __METHOD__ );
1720                         $this->mTitleProtection = false;
1721                 }
1722
1723                 # Update the protection log
1724                 if ( $dbw->affectedRows() ) {
1725                         $log = new LogPage( 'protect' );
1726
1727                         if ( $create_perm ) {
1728                                 $params = array( "[create=$create_perm] $expiry_description", '' );
1729                                 $log->addEntry( ( isset( $this->mRestrictions['create'] ) && $this->mRestrictions['create'] ) ? 'modify' : 'protect', $this, trim( $reason ), $params );
1730                         } else {
1731                                 $log->addEntry( 'unprotect', $this, $reason );
1732                         }
1733                 }
1734
1735                 return true;
1736         }
1737
1738         /**
1739          * Remove any title protection due to page existing
1740          */
1741         public function deleteTitleProtection() {
1742                 $dbw = wfGetDB( DB_MASTER );
1743
1744                 $dbw->delete(
1745                         'protected_titles',
1746                         array( 'pt_namespace' => $this->getNamespace(), 'pt_title' => $this->getDBkey() ),
1747                         __METHOD__
1748                 );
1749                 $this->mTitleProtection = false;
1750         }
1751
1752         /**
1753          * Would anybody with sufficient privileges be able to move this page?
1754          * Some pages just aren't movable.
1755          *
1756          * @return Bool TRUE or FALSE
1757          */
1758         public function isMovable() {
1759                 return MWNamespace::isMovable( $this->getNamespace() ) && $this->getInterwiki() == '';
1760         }
1761
1762         /**
1763          * Can $wgUser read this page?
1764          *
1765          * @return Bool
1766          * @todo fold these checks into userCan()
1767          */
1768         public function userCanRead() {
1769                 global $wgUser, $wgGroupPermissions;
1770
1771                 static $useShortcut = null;
1772
1773                 # Initialize the $useShortcut boolean, to determine if we can skip quite a bit of code below
1774                 if ( is_null( $useShortcut ) ) {
1775                         global $wgRevokePermissions;
1776                         $useShortcut = true;
1777                         if ( empty( $wgGroupPermissions['*']['read'] ) ) {
1778                                 # Not a public wiki, so no shortcut
1779                                 $useShortcut = false;
1780                         } elseif ( !empty( $wgRevokePermissions ) ) {
1781                                 /*
1782                                  * Iterate through each group with permissions being revoked (key not included since we don't care
1783                                  * what the group name is), then check if the read permission is being revoked. If it is, then
1784                                  * we don't use the shortcut below since the user might not be able to read, even though anon
1785                                  * reading is allowed.
1786                                  */
1787                                 foreach ( $wgRevokePermissions as $perms ) {
1788                                         if ( !empty( $perms['read'] ) ) {
1789                                                 # We might be removing the read right from the user, so no shortcut
1790                                                 $useShortcut = false;
1791                                                 break;
1792                                         }
1793                                 }
1794                         }
1795                 }
1796
1797                 $result = null;
1798                 wfRunHooks( 'userCan', array( &$this, &$wgUser, 'read', &$result ) );
1799                 if ( $result !== null ) {
1800                         return $result;
1801                 }
1802
1803                 # Shortcut for public wikis, allows skipping quite a bit of code
1804                 if ( $useShortcut ) {
1805                         return true;
1806                 }
1807
1808                 if ( $wgUser->isAllowed( 'read' ) ) {
1809                         return true;
1810                 } else {
1811                         global $wgWhitelistRead;
1812
1813                         # Always grant access to the login page.
1814                         # Even anons need to be able to log in.
1815                         if ( $this->isSpecial( 'Userlogin' ) || $this->isSpecial( 'Resetpass' ) ) {
1816                                 return true;
1817                         }
1818
1819                         # Bail out if there isn't whitelist
1820                         if ( !is_array( $wgWhitelistRead ) ) {
1821                                 return false;
1822                         }
1823
1824                         # Check for explicit whitelisting
1825                         $name = $this->getPrefixedText();
1826                         $dbName = $this->getPrefixedDBKey();
1827                         // Check with and without underscores
1828                         if ( in_array( $name, $wgWhitelistRead, true ) || in_array( $dbName, $wgWhitelistRead, true ) )
1829                                 return true;
1830
1831                         # Old settings might have the title prefixed with
1832                         # a colon for main-namespace pages
1833                         if ( $this->getNamespace() == NS_MAIN ) {
1834                                 if ( in_array( ':' . $name, $wgWhitelistRead ) ) {
1835                                         return true;
1836                                 }
1837                         }
1838
1839                         # If it's a special page, ditch the subpage bit and check again
1840                         if ( $this->getNamespace() == NS_SPECIAL ) {
1841                                 $name = $this->getDBkey();
1842                                 list( $name, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $name );
1843                                 if ( $name === false ) {
1844                                         # Invalid special page, but we show standard login required message
1845                                         return false;
1846                                 }
1847
1848                                 $pure = SpecialPage::getTitleFor( $name )->getPrefixedText();
1849                                 if ( in_array( $pure, $wgWhitelistRead, true ) ) {
1850                                         return true;
1851                                 }
1852                         }
1853
1854                 }
1855                 return false;
1856         }
1857
1858         /**
1859          * Is this the mainpage?
1860          * @note Title::newFromText seams to be sufficiently optimized by the title
1861          * cache that we don't need to over-optimize by doing direct comparisons and
1862          * acidentally creating new bugs where $title->equals( Title::newFromText() )
1863          * ends up reporting something differently than $title->isMainPage();
1864          *
1865          * @return Bool
1866          */
1867         public function isMainPage() {
1868                 return $this->equals( Title::newMainPage() );
1869         }
1870
1871         /**
1872          * Is this a talk page of some sort?
1873          *
1874          * @return Bool
1875          */
1876         public function isTalkPage() {
1877                 return MWNamespace::isTalk( $this->getNamespace() );
1878         }
1879
1880         /**
1881          * Is this a subpage?
1882          *
1883          * @return Bool
1884          */
1885         public function isSubpage() {
1886                 return MWNamespace::hasSubpages( $this->mNamespace )
1887                         ? strpos( $this->getText(), '/' ) !== false
1888                         : false;
1889         }
1890
1891         /**
1892          * Does this have subpages?  (Warning, usually requires an extra DB query.)
1893          *
1894          * @return Bool
1895          */
1896         public function hasSubpages() {
1897                 if ( !MWNamespace::hasSubpages( $this->mNamespace ) ) {
1898                         # Duh
1899                         return false;
1900                 }
1901
1902                 # We dynamically add a member variable for the purpose of this method
1903                 # alone to cache the result.  There's no point in having it hanging
1904                 # around uninitialized in every Title object; therefore we only add it
1905                 # if needed and don't declare it statically.
1906                 if ( isset( $this->mHasSubpages ) ) {
1907                         return $this->mHasSubpages;
1908                 }
1909
1910                 $subpages = $this->getSubpages( 1 );
1911                 if ( $subpages instanceof TitleArray ) {
1912                         return $this->mHasSubpages = (bool)$subpages->count();
1913                 }
1914                 return $this->mHasSubpages = false;
1915         }
1916
1917         /**
1918          * Get all subpages of this page.
1919          *
1920          * @param $limit Int maximum number of subpages to fetch; -1 for no limit
1921          * @return mixed TitleArray, or empty array if this page's namespace
1922          *  doesn't allow subpages
1923          */
1924         public function getSubpages( $limit = -1 ) {
1925                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
1926                         return array();
1927                 }
1928
1929                 $dbr = wfGetDB( DB_SLAVE );
1930                 $conds['page_namespace'] = $this->getNamespace();
1931                 $conds[] = 'page_title ' . $dbr->buildLike( $this->getDBkey() . '/', $dbr->anyString() );
1932                 $options = array();
1933                 if ( $limit > -1 ) {
1934                         $options['LIMIT'] = $limit;
1935                 }
1936                 return $this->mSubpages = TitleArray::newFromResult(
1937                         $dbr->select( 'page',
1938                                 array( 'page_id', 'page_namespace', 'page_title', 'page_is_redirect' ),
1939                                 $conds,
1940                                 __METHOD__,
1941                                 $options
1942                         )
1943                 );
1944         }
1945
1946         /**
1947          * Could this page contain custom CSS or JavaScript, based
1948          * on the title?
1949          *
1950          * @return Bool
1951          */
1952         public function isCssOrJsPage() {
1953                 return $this->mNamespace == NS_MEDIAWIKI
1954                         && preg_match( '!\.(?:css|js)$!u', $this->mTextform ) > 0;
1955         }
1956
1957         /**
1958          * Is this a .css or .js subpage of a user page?
1959          * @return Bool
1960          */
1961         public function isCssJsSubpage() {
1962                 return ( NS_USER == $this->mNamespace and preg_match( "/\\/.*\\.(?:css|js)$/", $this->mTextform ) );
1963         }
1964
1965         /**
1966          * Is this a *valid* .css or .js subpage of a user page?
1967          *
1968          * @return Bool
1969          * @deprecated since 1.17
1970          */
1971         public function isValidCssJsSubpage() {
1972                 return $this->isCssJsSubpage();
1973         }
1974
1975         /**
1976          * Trim down a .css or .js subpage title to get the corresponding skin name
1977          *
1978          * @return string containing skin name from .css or .js subpage title
1979          */
1980         public function getSkinFromCssJsSubpage() {
1981                 $subpage = explode( '/', $this->mTextform );
1982                 $subpage = $subpage[ count( $subpage ) - 1 ];
1983                 return( str_replace( array( '.css', '.js' ), array( '', '' ), $subpage ) );
1984         }
1985
1986         /**
1987          * Is this a .css subpage of a user page?
1988          *
1989          * @return Bool
1990          */
1991         public function isCssSubpage() {
1992                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.css$/", $this->mTextform ) );
1993         }
1994
1995         /**
1996          * Is this a .js subpage of a user page?
1997          *
1998          * @return Bool
1999          */
2000         public function isJsSubpage() {
2001                 return ( NS_USER == $this->mNamespace && preg_match( "/\\/.*\\.js$/", $this->mTextform ) );
2002         }
2003
2004         /**
2005          * Protect css subpages of user pages: can $wgUser edit
2006          * this page?
2007          *
2008          * @return Bool
2009          * @todo XXX: this might be better using restrictions
2010          */
2011         public function userCanEditCssSubpage() {
2012                 global $wgUser;
2013                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'editusercss' ) )
2014                         || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2015         }
2016
2017         /**
2018          * Protect js subpages of user pages: can $wgUser edit
2019          * this page?
2020          *
2021          * @return Bool
2022          * @todo XXX: this might be better using restrictions
2023          */
2024         public function userCanEditJsSubpage() {
2025                 global $wgUser;
2026                 return ( ( $wgUser->isAllowedAll( 'editusercssjs', 'edituserjs' ) )
2027                            || preg_match( '/^' . preg_quote( $wgUser->getName(), '/' ) . '\//', $this->mTextform ) );
2028         }
2029
2030         /**
2031          * Cascading protection: Return true if cascading restrictions apply to this page, false if not.
2032          *
2033          * @return Bool If the page is subject to cascading restrictions.
2034          */
2035         public function isCascadeProtected() {
2036                 list( $sources, /* $restrictions */ ) = $this->getCascadeProtectionSources( false );
2037                 return ( $sources > 0 );
2038         }
2039
2040         /**
2041          * Cascading protection: Get the source of any cascading restrictions on this page.
2042          *
2043          * @param $getPages Bool Whether or not to retrieve the actual pages
2044          *        that the restrictions have come from.
2045          * @return Mixed Array of Title objects of the pages from which cascading restrictions
2046          *     have come, false for none, or true if such restrictions exist, but $getPages
2047          *     was not set.  The restriction array is an array of each type, each of which
2048          *     contains a array of unique groups.
2049          */
2050         public function getCascadeProtectionSources( $getPages = true ) {
2051                 global $wgContLang;
2052                 $pagerestrictions = array();
2053
2054                 if ( isset( $this->mCascadeSources ) && $getPages ) {
2055                         return array( $this->mCascadeSources, $this->mCascadingRestrictions );
2056                 } else if ( isset( $this->mHasCascadingRestrictions ) && !$getPages ) {
2057                         return array( $this->mHasCascadingRestrictions, $pagerestrictions );
2058                 }
2059
2060                 wfProfileIn( __METHOD__ );
2061
2062                 $dbr = wfGetDB( DB_SLAVE );
2063
2064                 if ( $this->getNamespace() == NS_FILE ) {
2065                         $tables = array( 'imagelinks', 'page_restrictions' );
2066                         $where_clauses = array(
2067                                 'il_to' => $this->getDBkey(),
2068                                 'il_from=pr_page',
2069                                 'pr_cascade' => 1
2070                         );
2071                 } else {
2072                         $tables = array( 'templatelinks', 'page_restrictions' );
2073                         $where_clauses = array(
2074                                 'tl_namespace' => $this->getNamespace(),
2075                                 'tl_title' => $this->getDBkey(),
2076                                 'tl_from=pr_page',
2077                                 'pr_cascade' => 1
2078                         );
2079                 }
2080
2081                 if ( $getPages ) {
2082                         $cols = array( 'pr_page', 'page_namespace', 'page_title',
2083                                                    'pr_expiry', 'pr_type', 'pr_level' );
2084                         $where_clauses[] = 'page_id=pr_page';
2085                         $tables[] = 'page';
2086                 } else {
2087                         $cols = array( 'pr_expiry' );
2088                 }
2089
2090                 $res = $dbr->select( $tables, $cols, $where_clauses, __METHOD__ );
2091
2092                 $sources = $getPages ? array() : false;
2093                 $now = wfTimestampNow();
2094                 $purgeExpired = false;
2095
2096                 foreach ( $res as $row ) {
2097                         $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2098                         if ( $expiry > $now ) {
2099                                 if ( $getPages ) {
2100                                         $page_id = $row->pr_page;
2101                                         $page_ns = $row->page_namespace;
2102                                         $page_title = $row->page_title;
2103                                         $sources[$page_id] = Title::makeTitle( $page_ns, $page_title );
2104                                         # Add groups needed for each restriction type if its not already there
2105                                         # Make sure this restriction type still exists
2106
2107                                         if ( !isset( $pagerestrictions[$row->pr_type] ) ) {
2108                                                 $pagerestrictions[$row->pr_type] = array();
2109                                         }
2110
2111                                         if ( isset( $pagerestrictions[$row->pr_type] ) &&
2112                                                  !in_array( $row->pr_level, $pagerestrictions[$row->pr_type] ) ) {
2113                                                 $pagerestrictions[$row->pr_type][] = $row->pr_level;
2114                                         }
2115                                 } else {
2116                                         $sources = true;
2117                                 }
2118                         } else {
2119                                 // Trigger lazy purge of expired restrictions from the db
2120                                 $purgeExpired = true;
2121                         }
2122                 }
2123                 if ( $purgeExpired ) {
2124                         Title::purgeExpiredRestrictions();
2125                 }
2126
2127                 if ( $getPages ) {
2128                         $this->mCascadeSources = $sources;
2129                         $this->mCascadingRestrictions = $pagerestrictions;
2130                 } else {
2131                         $this->mHasCascadingRestrictions = $sources;
2132                 }
2133
2134                 wfProfileOut( __METHOD__ );
2135                 return array( $sources, $pagerestrictions );
2136         }
2137
2138         /**
2139          * Returns cascading restrictions for the current article
2140          *
2141          * @return Boolean
2142          */
2143         function areRestrictionsCascading() {
2144                 if ( !$this->mRestrictionsLoaded ) {
2145                         $this->loadRestrictions();
2146                 }
2147
2148                 return $this->mCascadeRestriction;
2149         }
2150
2151         /**
2152          * Loads a string into mRestrictions array
2153          *
2154          * @param $res Resource restrictions as an SQL result.
2155          * @param $oldFashionedRestrictions String comma-separated list of page
2156          *        restrictions from page table (pre 1.10)
2157          */
2158         private function loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions = null ) {
2159                 $rows = array();
2160
2161                 foreach ( $res as $row ) {
2162                         $rows[] = $row;
2163                 }
2164
2165                 $this->loadRestrictionsFromRows( $rows, $oldFashionedRestrictions );
2166         }
2167
2168         /**
2169          * Compiles list of active page restrictions from both page table (pre 1.10)
2170          * and page_restrictions table for this existing page.
2171          * Public for usage by LiquidThreads.
2172          *
2173          * @param $rows array of db result objects
2174          * @param $oldFashionedRestrictions string comma-separated list of page
2175          *        restrictions from page table (pre 1.10)
2176          */
2177         public function loadRestrictionsFromRows( $rows, $oldFashionedRestrictions = null ) {
2178                 global $wgContLang;
2179                 $dbr = wfGetDB( DB_SLAVE );
2180
2181                 $restrictionTypes = $this->getRestrictionTypes();
2182
2183                 foreach ( $restrictionTypes as $type ) {
2184                         $this->mRestrictions[$type] = array();
2185                         $this->mRestrictionsExpiry[$type] = $wgContLang->formatExpiry( '', TS_MW );
2186                 }
2187
2188                 $this->mCascadeRestriction = false;
2189
2190                 # Backwards-compatibility: also load the restrictions from the page record (old format).
2191
2192                 if ( $oldFashionedRestrictions === null ) {
2193                         $oldFashionedRestrictions = $dbr->selectField( 'page', 'page_restrictions',
2194                                 array( 'page_id' => $this->getArticleId() ), __METHOD__ );
2195                 }
2196
2197                 if ( $oldFashionedRestrictions != '' ) {
2198
2199                         foreach ( explode( ':', trim( $oldFashionedRestrictions ) ) as $restrict ) {
2200                                 $temp = explode( '=', trim( $restrict ) );
2201                                 if ( count( $temp ) == 1 ) {
2202                                         // old old format should be treated as edit/move restriction
2203                                         $this->mRestrictions['edit'] = explode( ',', trim( $temp[0] ) );
2204                                         $this->mRestrictions['move'] = explode( ',', trim( $temp[0] ) );
2205                                 } else {
2206                                         $this->mRestrictions[$temp[0]] = explode( ',', trim( $temp[1] ) );
2207                                 }
2208                         }
2209
2210                         $this->mOldRestrictions = true;
2211
2212                 }
2213
2214                 if ( count( $rows ) ) {
2215                         # Current system - load second to make them override.
2216                         $now = wfTimestampNow();
2217                         $purgeExpired = false;
2218
2219                         # Cycle through all the restrictions.
2220                         foreach ( $rows as $row ) {
2221
2222                                 // Don't take care of restrictions types that aren't allowed
2223                                 if ( !in_array( $row->pr_type, $restrictionTypes ) )
2224                                         continue;
2225
2226                                 // This code should be refactored, now that it's being used more generally,
2227                                 // But I don't really see any harm in leaving it in Block for now -werdna
2228                                 $expiry = $wgContLang->formatExpiry( $row->pr_expiry, TS_MW );
2229
2230                                 // Only apply the restrictions if they haven't expired!
2231                                 if ( !$expiry || $expiry > $now ) {
2232                                         $this->mRestrictionsExpiry[$row->pr_type] = $expiry;
2233                                         $this->mRestrictions[$row->pr_type] = explode( ',', trim( $row->pr_level ) );
2234
2235                                         $this->mCascadeRestriction |= $row->pr_cascade;
2236                                 } else {
2237                                         // Trigger a lazy purge of expired restrictions
2238                                         $purgeExpired = true;
2239                                 }
2240                         }
2241
2242                         if ( $purgeExpired ) {
2243                                 Title::purgeExpiredRestrictions();
2244                         }
2245                 }
2246
2247                 $this->mRestrictionsLoaded = true;
2248         }
2249
2250         /**
2251          * Load restrictions from the page_restrictions table
2252          *
2253          * @param $oldFashionedRestrictions String comma-separated list of page
2254          *        restrictions from page table (pre 1.10)
2255          */
2256         public function loadRestrictions( $oldFashionedRestrictions = null ) {
2257                 global $wgContLang;
2258                 if ( !$this->mRestrictionsLoaded ) {
2259                         if ( $this->exists() ) {
2260                                 $dbr = wfGetDB( DB_SLAVE );
2261
2262                                 $res = $dbr->select(
2263                                         'page_restrictions',
2264                                         '*',
2265                                         array( 'pr_page' => $this->getArticleId() ),
2266                                         __METHOD__
2267                                 );
2268
2269                                 $this->loadRestrictionsFromResultWrapper( $res, $oldFashionedRestrictions );
2270                         } else {
2271                                 $title_protection = $this->getTitleProtection();
2272
2273                                 if ( $title_protection ) {
2274                                         $now = wfTimestampNow();
2275                                         $expiry = $wgContLang->formatExpiry( $title_protection['pt_expiry'], TS_MW );
2276
2277                                         if ( !$expiry || $expiry > $now ) {
2278                                                 // Apply the restrictions
2279                                                 $this->mRestrictionsExpiry['create'] = $expiry;
2280                                                 $this->mRestrictions['create'] = explode( ',', trim( $title_protection['pt_create_perm'] ) );
2281                                         } else { // Get rid of the old restrictions
2282                                                 Title::purgeExpiredRestrictions();
2283                                                 $this->mTitleProtection = false;
2284                                         }
2285                                 } else {
2286                                         $this->mRestrictionsExpiry['create'] = $wgContLang->formatExpiry( '', TS_MW );
2287                                 }
2288                                 $this->mRestrictionsLoaded = true;
2289                         }
2290                 }
2291         }
2292
2293         /**
2294          * Purge expired restrictions from the page_restrictions table
2295          */
2296         static function purgeExpiredRestrictions() {
2297                 $dbw = wfGetDB( DB_MASTER );
2298                 $dbw->delete(
2299                         'page_restrictions',
2300                         array( 'pr_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2301                         __METHOD__
2302                 );
2303
2304                 $dbw->delete(
2305                         'protected_titles',
2306                         array( 'pt_expiry < ' . $dbw->addQuotes( $dbw->timestamp() ) ),
2307                         __METHOD__
2308                 );
2309         }
2310
2311         /**
2312          * Accessor/initialisation for mRestrictions
2313          *
2314          * @param $action String action that permission needs to be checked for
2315          * @return Array of Strings the array of groups allowed to edit this article
2316          */
2317         public function getRestrictions( $action ) {
2318                 if ( !$this->mRestrictionsLoaded ) {
2319                         $this->loadRestrictions();
2320                 }
2321                 return isset( $this->mRestrictions[$action] )
2322                                 ? $this->mRestrictions[$action]
2323                                 : array();
2324         }
2325
2326         /**
2327          * Get the expiry time for the restriction against a given action
2328          *
2329          * @return String|Bool 14-char timestamp, or 'infinity' if the page is protected forever
2330          *      or not protected at all, or false if the action is not recognised.
2331          */
2332         public function getRestrictionExpiry( $action ) {
2333                 if ( !$this->mRestrictionsLoaded ) {
2334                         $this->loadRestrictions();
2335                 }
2336                 return isset( $this->mRestrictionsExpiry[$action] ) ? $this->mRestrictionsExpiry[$action] : false;
2337         }
2338
2339         /**
2340          * Is there a version of this page in the deletion archive?
2341          *
2342          * @return Int the number of archived revisions
2343          */
2344         public function isDeleted() {
2345                 if ( $this->getNamespace() < 0 ) {
2346                         $n = 0;
2347                 } else {
2348                         $dbr = wfGetDB( DB_SLAVE );
2349                         $n = $dbr->selectField( 'archive', 'COUNT(*)',
2350                                 array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2351                                 __METHOD__
2352                         );
2353                         if ( $this->getNamespace() == NS_FILE ) {
2354                                 $n += $dbr->selectField( 'filearchive', 'COUNT(*)',
2355                                         array( 'fa_name' => $this->getDBkey() ),
2356                                         __METHOD__
2357                                 );
2358                         }
2359                 }
2360                 return (int)$n;
2361         }
2362
2363         /**
2364          * Is there a version of this page in the deletion archive?
2365          *
2366          * @return Boolean
2367          */
2368         public function isDeletedQuick() {
2369                 if ( $this->getNamespace() < 0 ) {
2370                         return false;
2371                 }
2372                 $dbr = wfGetDB( DB_SLAVE );
2373                 $deleted = (bool)$dbr->selectField( 'archive', '1',
2374                         array( 'ar_namespace' => $this->getNamespace(), 'ar_title' => $this->getDBkey() ),
2375                         __METHOD__
2376                 );
2377                 if ( !$deleted && $this->getNamespace() == NS_FILE ) {
2378                         $deleted = (bool)$dbr->selectField( 'filearchive', '1',
2379                                 array( 'fa_name' => $this->getDBkey() ),
2380                                 __METHOD__
2381                         );
2382                 }
2383                 return $deleted;
2384         }
2385
2386         /**
2387          * Get the article ID for this Title from the link cache,
2388          * adding it if necessary
2389          *
2390          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select
2391          *  for update
2392          * @return Int the ID
2393          */
2394         public function getArticleID( $flags = 0 ) {
2395                 if ( $this->getNamespace() < 0 ) {
2396                         return $this->mArticleID = 0;
2397                 }
2398                 $linkCache = LinkCache::singleton();
2399                 if ( $flags & self::GAID_FOR_UPDATE ) {
2400                         $oldUpdate = $linkCache->forUpdate( true );
2401                         $linkCache->clearLink( $this );
2402                         $this->mArticleID = $linkCache->addLinkObj( $this );
2403                         $linkCache->forUpdate( $oldUpdate );
2404                 } else {
2405                         if ( -1 == $this->mArticleID ) {
2406                                 $this->mArticleID = $linkCache->addLinkObj( $this );
2407                         }
2408                 }
2409                 return $this->mArticleID;
2410         }
2411
2412         /**
2413          * Is this an article that is a redirect page?
2414          * Uses link cache, adding it if necessary
2415          *
2416          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2417          * @return Bool
2418          */
2419         public function isRedirect( $flags = 0 ) {
2420                 if ( !is_null( $this->mRedirect ) ) {
2421                         return $this->mRedirect;
2422                 }
2423                 # Calling getArticleID() loads the field from cache as needed
2424                 if ( !$this->getArticleID( $flags ) ) {
2425                         return $this->mRedirect = false;
2426                 }
2427                 $linkCache = LinkCache::singleton();
2428                 $this->mRedirect = (bool)$linkCache->getGoodLinkFieldObj( $this, 'redirect' );
2429
2430                 return $this->mRedirect;
2431         }
2432
2433         /**
2434          * What is the length of this page?
2435          * Uses link cache, adding it if necessary
2436          *
2437          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2438          * @return Int
2439          */
2440         public function getLength( $flags = 0 ) {
2441                 if ( $this->mLength != -1 ) {
2442                         return $this->mLength;
2443                 }
2444                 # Calling getArticleID() loads the field from cache as needed
2445                 if ( !$this->getArticleID( $flags ) ) {
2446                         return $this->mLength = 0;
2447                 }
2448                 $linkCache = LinkCache::singleton();
2449                 $this->mLength = intval( $linkCache->getGoodLinkFieldObj( $this, 'length' ) );
2450
2451                 return $this->mLength;
2452         }
2453
2454         /**
2455          * What is the page_latest field for this page?
2456          *
2457          * @param $flags Int a bit field; may be Title::GAID_FOR_UPDATE to select for update
2458          * @return Int or 0 if the page doesn't exist
2459          */
2460         public function getLatestRevID( $flags = 0 ) {
2461                 if ( $this->mLatestID !== false ) {
2462                         return intval( $this->mLatestID );
2463                 }
2464                 # Calling getArticleID() loads the field from cache as needed
2465                 if ( !$this->getArticleID( $flags ) ) {
2466                         return $this->mLatestID = 0;
2467                 }
2468                 $linkCache = LinkCache::singleton();
2469                 $this->mLatestID = intval( $linkCache->getGoodLinkFieldObj( $this, 'revision' ) );
2470
2471                 return $this->mLatestID;
2472         }
2473
2474         /**
2475          * This clears some fields in this object, and clears any associated
2476          * keys in the "bad links" section of the link cache.
2477          *
2478          * - This is called from Article::doEdit() and Article::insertOn() to allow
2479          * loading of the new page_id. It's also called from
2480          * Article::doDeleteArticle()
2481          *
2482          * @param $newid Int the new Article ID
2483          */
2484         public function resetArticleID( $newid ) {
2485                 $linkCache = LinkCache::singleton();
2486                 $linkCache->clearBadLink( $this->getPrefixedDBkey() );
2487
2488                 if ( $newid === false ) {
2489                         $this->mArticleID = -1;
2490                 } else {
2491                         $this->mArticleID = intval( $newid );
2492                 }
2493                 $this->mRestrictionsLoaded = false;
2494                 $this->mRestrictions = array();
2495                 $this->mRedirect = null;
2496                 $this->mLength = -1;
2497                 $this->mLatestID = false;
2498         }
2499
2500         /**
2501          * Updates page_touched for this page; called from LinksUpdate.php
2502          *
2503          * @return Bool true if the update succeded
2504          */
2505         public function invalidateCache() {
2506                 if ( wfReadOnly() ) {
2507                         return;
2508                 }
2509                 $dbw = wfGetDB( DB_MASTER );
2510                 $success = $dbw->update(
2511                         'page',
2512                         array( 'page_touched' => $dbw->timestamp() ),
2513                         $this->pageCond(),
2514                         __METHOD__
2515                 );
2516                 HTMLFileCache::clearFileCache( $this );
2517                 return $success;
2518         }
2519
2520         /**
2521          * Prefix some arbitrary text with the namespace or interwiki prefix
2522          * of this object
2523          *
2524          * @param $name String the text
2525          * @return String the prefixed text
2526          * @private
2527          */
2528         /* private */ function prefix( $name ) {
2529                 $p = '';
2530                 if ( $this->mInterwiki != '' ) {
2531                         $p = $this->mInterwiki . ':';
2532                 }
2533
2534                 if ( 0 != $this->mNamespace ) {
2535                         $p .= $this->getNsText() . ':';
2536                 }
2537                 return $p . $name;
2538         }
2539
2540         /**
2541          * Returns a simple regex that will match on characters and sequences invalid in titles.
2542          * Note that this doesn't pick up many things that could be wrong with titles, but that
2543          * replacing this regex with something valid will make many titles valid.
2544          *
2545          * @return String regex string
2546          */
2547         static function getTitleInvalidRegex() {
2548                 static $rxTc = false;
2549                 if ( !$rxTc ) {
2550                         # Matching titles will be held as illegal.
2551                         $rxTc = '/' .
2552                                 # Any character not allowed is forbidden...
2553                                 '[^' . Title::legalChars() . ']' .
2554                                 # URL percent encoding sequences interfere with the ability
2555                                 # to round-trip titles -- you can't link to them consistently.
2556                                 '|%[0-9A-Fa-f]{2}' .
2557                                 # XML/HTML character references produce similar issues.
2558                                 '|&[A-Za-z0-9\x80-\xff]+;' .
2559                                 '|&#[0-9]+;' .
2560                                 '|&#x[0-9A-Fa-f]+;' .
2561                                 '/S';
2562                 }
2563
2564                 return $rxTc;
2565         }
2566
2567         /**
2568          * Capitalize a text string for a title if it belongs to a namespace that capitalizes
2569          *
2570          * @param $text String containing title to capitalize
2571          * @param $ns int namespace index, defaults to NS_MAIN
2572          * @return String containing capitalized title
2573          */
2574         public static function capitalize( $text, $ns = NS_MAIN ) {
2575                 global $wgContLang;
2576
2577                 if ( MWNamespace::isCapitalized( $ns ) ) {
2578                         return $wgContLang->ucfirst( $text );
2579                 } else {
2580                         return $text;
2581                 }
2582         }
2583
2584         /**
2585          * Secure and split - main initialisation function for this object
2586          *
2587          * Assumes that mDbkeyform has been set, and is urldecoded
2588          * and uses underscores, but not otherwise munged.  This function
2589          * removes illegal characters, splits off the interwiki and
2590          * namespace prefixes, sets the other forms, and canonicalizes
2591          * everything.
2592          *
2593          * @return Bool true on success
2594          */
2595         private function secureAndSplit() {
2596                 global $wgContLang, $wgLocalInterwiki;
2597
2598                 # Initialisation
2599                 $rxTc = self::getTitleInvalidRegex();
2600
2601                 $this->mInterwiki = $this->mFragment = '';
2602                 $this->mNamespace = $this->mDefaultNamespace; # Usually NS_MAIN
2603
2604                 $dbkey = $this->mDbkeyform;
2605
2606                 # Strip Unicode bidi override characters.
2607                 # Sometimes they slip into cut-n-pasted page titles, where the
2608                 # override chars get included in list displays.
2609                 $dbkey = preg_replace( '/\xE2\x80[\x8E\x8F\xAA-\xAE]/S', '', $dbkey );
2610
2611                 # Clean up whitespace
2612                 # Note: use of the /u option on preg_replace here will cause
2613                 # input with invalid UTF-8 sequences to be nullified out in PHP 5.2.x,
2614                 # conveniently disabling them.
2615                 $dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
2616                 $dbkey = trim( $dbkey, '_' );
2617
2618                 if ( $dbkey == '' ) {
2619                         return false;
2620                 }
2621
2622                 if ( false !== strpos( $dbkey, UTF8_REPLACEMENT ) ) {
2623                         # Contained illegal UTF-8 sequences or forbidden Unicode chars.
2624                         return false;
2625                 }
2626
2627                 $this->mDbkeyform = $dbkey;
2628
2629                 # Initial colon indicates main namespace rather than specified default
2630                 # but should not create invalid {ns,title} pairs such as {0,Project:Foo}
2631                 if ( ':' == $dbkey { 0 } ) {
2632                         $this->mNamespace = NS_MAIN;
2633                         $dbkey = substr( $dbkey, 1 ); # remove the colon but continue processing
2634                         $dbkey = trim( $dbkey, '_' ); # remove any subsequent whitespace
2635                 }
2636
2637                 # Namespace or interwiki prefix
2638                 $firstPass = true;
2639                 $prefixRegexp = "/^(.+?)_*:_*(.*)$/S";
2640                 do {
2641                         $m = array();
2642                         if ( preg_match( $prefixRegexp, $dbkey, $m ) ) {
2643                                 $p = $m[1];
2644                                 if ( ( $ns = $wgContLang->getNsIndex( $p ) ) !== false ) {
2645                                         # Ordinary namespace
2646                                         $dbkey = $m[2];
2647                                         $this->mNamespace = $ns;
2648                                         # For Talk:X pages, check if X has a "namespace" prefix
2649                                         if ( $ns == NS_TALK && preg_match( $prefixRegexp, $dbkey, $x ) ) {
2650                                                 if ( $wgContLang->getNsIndex( $x[1] ) ) {
2651                                                         # Disallow Talk:File:x type titles...
2652                                                         return false;
2653                                                 } else if ( Interwiki::isValidInterwiki( $x[1] ) ) {
2654                                                         # Disallow Talk:Interwiki:x type titles...
2655                                                         return false;
2656                                                 }
2657                                         }
2658                                 } elseif ( Interwiki::isValidInterwiki( $p ) ) {
2659                                         if ( !$firstPass ) {
2660                                                 # Can't make a local interwiki link to an interwiki link.
2661                                                 # That's just crazy!
2662                                                 return false;
2663                                         }
2664
2665                                         # Interwiki link
2666                                         $dbkey = $m[2];
2667                                         $this->mInterwiki = $wgContLang->lc( $p );
2668
2669                                         # Redundant interwiki prefix to the local wiki
2670                                         if ( $wgLocalInterwiki !== false
2671                                                 && 0 == strcasecmp( $this->mInterwiki, $wgLocalInterwiki ) )
2672                                         {
2673                                                 if ( $dbkey == '' ) {
2674                                                         # Can't have an empty self-link
2675                                                         return false;
2676                                                 }
2677                                                 $this->mInterwiki = '';
2678                                                 $firstPass = false;
2679                                                 # Do another namespace split...
2680                                                 continue;
2681                                         }
2682
2683                                         # If there's an initial colon after the interwiki, that also
2684                                         # resets the default namespace
2685                                         if ( $dbkey !== '' && $dbkey[0] == ':' ) {
2686                                                 $this->mNamespace = NS_MAIN;
2687                                                 $dbkey = substr( $dbkey, 1 );
2688                                         }
2689                                 }
2690                                 # If there's no recognized interwiki or namespace,
2691                                 # then let the colon expression be part of the title.
2692                         }
2693                         break;
2694                 } while ( true );
2695
2696                 # We already know that some pages won't be in the database!
2697                 if ( $this->mInterwiki != '' || NS_SPECIAL == $this->mNamespace ) {
2698                         $this->mArticleID = 0;
2699                 }
2700                 $fragment = strstr( $dbkey, '#' );
2701                 if ( false !== $fragment ) {
2702                         $this->setFragment( preg_replace( '/^#_*/', '#', $fragment ) );
2703                         $dbkey = substr( $dbkey, 0, strlen( $dbkey ) - strlen( $fragment ) );
2704                         # remove whitespace again: prevents "Foo_bar_#"
2705                         # becoming "Foo_bar_"
2706                         $dbkey = preg_replace( '/_*$/', '', $dbkey );
2707                 }
2708
2709                 # Reject illegal characters.
2710                 if ( preg_match( $rxTc, $dbkey ) ) {
2711                         return false;
2712                 }
2713
2714                 # Pages with "/./" or "/../" appearing in the URLs will often be un-
2715                 # reachable due to the way web browsers deal with 'relative' URLs.
2716                 # Also, they conflict with subpage syntax.  Forbid them explicitly.
2717                 if ( strpos( $dbkey, '.' ) !== false &&
2718                          ( $dbkey === '.' || $dbkey === '..' ||
2719                            strpos( $dbkey, './' ) === 0  ||
2720                            strpos( $dbkey, '../' ) === 0 ||
2721                            strpos( $dbkey, '/./' ) !== false ||
2722                            strpos( $dbkey, '/../' ) !== false  ||
2723                            substr( $dbkey, -2 ) == '/.' ||
2724                            substr( $dbkey, -3 ) == '/..' ) )
2725                 {
2726                         return false;
2727                 }
2728
2729                 # Magic tilde sequences? Nu-uh!
2730                 if ( strpos( $dbkey, '~~~' ) !== false ) {
2731                         return false;
2732                 }
2733
2734                 # Limit the size of titles to 255 bytes. This is typically the size of the
2735                 # underlying database field. We make an exception for special pages, which
2736                 # don't need to be stored in the database, and may edge over 255 bytes due
2737                 # to subpage syntax for long titles, e.g. [[Special:Block/Long name]]
2738                 if ( ( $this->mNamespace != NS_SPECIAL && strlen( $dbkey ) > 255 ) ||
2739                   strlen( $dbkey ) > 512 )
2740                 {
2741                         return false;
2742                 }
2743
2744                 # Normally, all wiki links are forced to have an initial capital letter so [[foo]]
2745                 # and [[Foo]] point to the same place.  Don't force it for interwikis, since the
2746                 # other site might be case-sensitive.
2747                 $this->mUserCaseDBKey = $dbkey;
2748                 if ( $this->mInterwiki == '' ) {
2749                         $dbkey = self::capitalize( $dbkey, $this->mNamespace );
2750                 }
2751
2752                 # Can't make a link to a namespace alone... "empty" local links can only be
2753                 # self-links with a fragment identifier.
2754                 if ( $dbkey == '' && $this->mInterwiki == '' && $this->mNamespace != NS_MAIN ) {
2755                         return false;
2756                 }
2757
2758                 // Allow IPv6 usernames to start with '::' by canonicalizing IPv6 titles.
2759                 // IP names are not allowed for accounts, and can only be referring to
2760                 // edits from the IP. Given '::' abbreviations and caps/lowercaps,
2761                 // there are numerous ways to present the same IP. Having sp:contribs scan
2762                 // them all is silly and having some show the edits and others not is
2763                 // inconsistent. Same for talk/userpages. Keep them normalized instead.
2764                 $dbkey = ( $this->mNamespace == NS_USER || $this->mNamespace == NS_USER_TALK )
2765                         ? IP::sanitizeIP( $dbkey )
2766                         : $dbkey;
2767
2768                 // Any remaining initial :s are illegal.
2769                 if ( $dbkey !== '' && ':' == $dbkey { 0 } ) {
2770                         return false;
2771                 }
2772
2773                 # Fill fields
2774                 $this->mDbkeyform = $dbkey;
2775                 $this->mUrlform = wfUrlencode( $dbkey );
2776
2777                 $this->mTextform = str_replace( '_', ' ', $dbkey );
2778
2779                 return true;
2780         }
2781
2782         /**
2783          * Set the fragment for this title. Removes the first character from the
2784          * specified fragment before setting, so it assumes you're passing it with
2785          * an initial "#".
2786          *
2787          * Deprecated for public use, use Title::makeTitle() with fragment parameter.
2788          * Still in active use privately.
2789          *
2790          * @param $fragment String text
2791          */
2792         public function setFragment( $fragment ) {
2793                 $this->mFragment = str_replace( '_', ' ', substr( $fragment, 1 ) );
2794         }
2795
2796         /**
2797          * Get a Title object associated with the talk page of this article
2798          *
2799          * @return Title the object for the talk page
2800          */
2801         public function getTalkPage() {
2802                 return Title::makeTitle( MWNamespace::getTalk( $this->getNamespace() ), $this->getDBkey() );
2803         }
2804
2805         /**
2806          * Get a title object associated with the subject page of this
2807          * talk page
2808          *
2809          * @return Title the object for the subject page
2810          */
2811         public function getSubjectPage() {
2812                 // Is this the same title?
2813                 $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
2814                 if ( $this->getNamespace() == $subjectNS ) {
2815                         return $this;
2816                 }
2817                 return Title::makeTitle( $subjectNS, $this->getDBkey() );
2818         }
2819
2820         /**
2821          * Get an array of Title objects linking to this Title
2822          * Also stores the IDs in the link cache.
2823          *
2824          * WARNING: do not use this function on arbitrary user-supplied titles!
2825          * On heavily-used templates it will max out the memory.
2826          *
2827          * @param $options Array: may be FOR UPDATE
2828          * @param $table String: table name
2829          * @param $prefix String: fields prefix
2830          * @return Array of Title objects linking here
2831          */
2832         public function getLinksTo( $options = array(), $table = 'pagelinks', $prefix = 'pl' ) {
2833                 $linkCache = LinkCache::singleton();
2834
2835                 if ( count( $options ) > 0 ) {
2836                         $db = wfGetDB( DB_MASTER );
2837                 } else {
2838                         $db = wfGetDB( DB_SLAVE );
2839                 }
2840
2841                 $res = $db->select(
2842                         array( 'page', $table ),
2843                         array( 'page_namespace', 'page_title', 'page_id', 'page_len', 'page_is_redirect', 'page_latest' ),
2844                         array(
2845                                 "{$prefix}_from=page_id",
2846                                 "{$prefix}_namespace" => $this->getNamespace(),
2847                                 "{$prefix}_title"     => $this->getDBkey() ),
2848                         __METHOD__,
2849                         $options
2850                 );
2851
2852                 $retVal = array();
2853                 if ( $db->numRows( $res ) ) {
2854                         foreach ( $res as $row ) {
2855                                 $titleObj = Title::makeTitle( $row->page_namespace, $row->page_title );
2856                                 if ( $titleObj ) {
2857                                         $linkCache->addGoodLinkObj( $row->page_id, $titleObj, $row->page_len, $row->page_is_redirect, $row->page_latest );
2858                                         $retVal[] = $titleObj;
2859                                 }
2860                         }
2861                 }
2862                 return $retVal;
2863         }
2864
2865         /**
2866          * Get an array of Title objects using this Title as a template
2867          * Also stores the IDs in the link cache.
2868          *
2869          * WARNING: do not use this function on arbitrary user-supplied titles!
2870          * On heavily-used templates it will max out the memory.
2871          *
2872          * @param $options Array: may be FOR UPDATE
2873          * @return Array of Title the Title objects linking here
2874          */
2875         public function getTemplateLinksTo( $options = array() ) {
2876                 return $this->getLinksTo( $options, 'templatelinks', 'tl' );
2877         }
2878
2879         /**
2880          * Get an array of Title objects referring to non-existent articles linked from this page
2881          *
2882          * @todo check if needed (used only in SpecialBrokenRedirects.php, and should use redirect table in this case)
2883          * @return Array of Title the Title objects
2884          */
2885         public function getBrokenLinksFrom() {
2886                 if ( $this->getArticleId() == 0 ) {
2887                         # All links from article ID 0 are false positives
2888                         return array();
2889                 }
2890
2891                 $dbr = wfGetDB( DB_SLAVE );
2892                 $res = $dbr->select(
2893                         array( 'page', 'pagelinks' ),
2894                         array( 'pl_namespace', 'pl_title' ),
2895                         array(
2896                                 'pl_from' => $this->getArticleId(),
2897                                 'page_namespace IS NULL'
2898                         ),
2899                         __METHOD__, array(),
2900                         array(
2901                                 'page' => array(
2902                                         'LEFT JOIN',
2903                                         array( 'pl_namespace=page_namespace', 'pl_title=page_title' )
2904                                 )
2905                         )
2906                 );
2907
2908                 $retVal = array();
2909                 foreach ( $res as $row ) {
2910                         $retVal[] = Title::makeTitle( $row->pl_namespace, $row->pl_title );
2911                 }
2912                 return $retVal;
2913         }
2914
2915
2916         /**
2917          * Get a list of URLs to purge from the Squid cache when this
2918          * page changes
2919          *
2920          * @return Array of String the URLs
2921          */
2922         public function getSquidURLs() {
2923                 global $wgContLang;
2924
2925                 $urls = array(
2926                         $this->getInternalURL(),
2927                         $this->getInternalURL( 'action=history' )
2928                 );
2929
2930                 // purge variant urls as well
2931                 if ( $wgContLang->hasVariants() ) {
2932                         $variants = $wgContLang->getVariants();
2933                         foreach ( $variants as $vCode ) {
2934                                 $urls[] = $this->getInternalURL( '', $vCode );
2935                         }
2936                 }
2937
2938                 return $urls;
2939         }
2940
2941         /**
2942          * Purge all applicable Squid URLs
2943          */
2944         public function purgeSquid() {
2945                 global $wgUseSquid;
2946                 if ( $wgUseSquid ) {
2947                         $urls = $this->getSquidURLs();
2948                         $u = new SquidUpdate( $urls );
2949                         $u->doUpdate();
2950                 }
2951         }
2952
2953         /**
2954          * Move this page without authentication
2955          *
2956          * @param $nt Title the new page Title
2957          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
2958          */
2959         public function moveNoAuth( &$nt ) {
2960                 return $this->moveTo( $nt, false );
2961         }
2962
2963         /**
2964          * Check whether a given move operation would be valid.
2965          * Returns true if ok, or a getUserPermissionsErrors()-like array otherwise
2966          *
2967          * @param $nt Title the new title
2968          * @param $auth Bool indicates whether $wgUser's permissions
2969          *  should be checked
2970          * @param $reason String is the log summary of the move, used for spam checking
2971          * @return Mixed True on success, getUserPermissionsErrors()-like array on failure
2972          */
2973         public function isValidMoveOperation( &$nt, $auth = true, $reason = '' ) {
2974                 global $wgUser;
2975
2976                 $errors = array();
2977                 if ( !$nt ) {
2978                         // Normally we'd add this to $errors, but we'll get
2979                         // lots of syntax errors if $nt is not an object
2980                         return array( array( 'badtitletext' ) );
2981                 }
2982                 if ( $this->equals( $nt ) ) {
2983                         $errors[] = array( 'selfmove' );
2984                 }
2985                 if ( !$this->isMovable() ) {
2986                         $errors[] = array( 'immobile-source-namespace', $this->getNsText() );
2987                 }
2988                 if ( $nt->getInterwiki() != '' ) {
2989                         $errors[] = array( 'immobile-target-namespace-iw' );
2990                 }
2991                 if ( !$nt->isMovable() ) {
2992                         $errors[] = array( 'immobile-target-namespace', $nt->getNsText() );
2993                 }
2994
2995                 $oldid = $this->getArticleID();
2996                 $newid = $nt->getArticleID();
2997
2998                 if ( strlen( $nt->getDBkey() ) < 1 ) {
2999                         $errors[] = array( 'articleexists' );
3000                 }
3001                 if ( ( $this->getDBkey() == '' ) ||
3002                          ( !$oldid ) ||
3003                          ( $nt->getDBkey() == '' ) ) {
3004                         $errors[] = array( 'badarticleerror' );
3005                 }
3006
3007                 // Image-specific checks
3008                 if ( $this->getNamespace() == NS_FILE ) {
3009                         $errors = array_merge( $errors, $this->validateFileMoveOperation( $nt ) );
3010                 }
3011
3012                 if ( $nt->getNamespace() == NS_FILE && $this->getNamespace() != NS_FILE ) {
3013                         $errors[] = array( 'nonfile-cannot-move-to-file' );
3014                 }
3015
3016                 if ( $auth ) {
3017                         $errors = wfMergeErrorArrays( $errors,
3018                                 $this->getUserPermissionsErrors( 'move', $wgUser ),
3019                                 $this->getUserPermissionsErrors( 'edit', $wgUser ),
3020                                 $nt->getUserPermissionsErrors( 'move-target', $wgUser ),
3021                                 $nt->getUserPermissionsErrors( 'edit', $wgUser ) );
3022                 }
3023
3024                 $match = EditPage::matchSummarySpamRegex( $reason );
3025                 if ( $match !== false ) {
3026                         // This is kind of lame, won't display nice
3027                         $errors[] = array( 'spamprotectiontext' );
3028                 }
3029
3030                 $err = null;
3031                 if ( !wfRunHooks( 'AbortMove', array( $this, $nt, $wgUser, &$err, $reason ) ) ) {
3032                         $errors[] = array( 'hookaborted', $err );
3033                 }
3034
3035                 # The move is allowed only if (1) the target doesn't exist, or
3036                 # (2) the target is a redirect to the source, and has no history
3037                 # (so we can undo bad moves right after they're done).
3038
3039                 if ( 0 != $newid ) { # Target exists; check for validity
3040                         if ( !$this->isValidMoveTarget( $nt ) ) {
3041                                 $errors[] = array( 'articleexists' );
3042                         }
3043                 } else {
3044                         $tp = $nt->getTitleProtection();
3045                         $right = ( $tp['pt_create_perm'] == 'sysop' ) ? 'protect' : $tp['pt_create_perm'];
3046                         if ( $tp and !$wgUser->isAllowed( $right ) ) {
3047                                 $errors[] = array( 'cantmove-titleprotected' );
3048                         }
3049                 }
3050                 if ( empty( $errors ) ) {
3051                         return true;
3052                 }
3053                 return $errors;
3054         }
3055
3056         /**
3057          * Check if the requested move target is a valid file move target
3058          * @param Title $nt Target title
3059          * @return array List of errors
3060          */
3061         protected function validateFileMoveOperation( $nt ) {
3062                 global $wgUser;
3063
3064                 $errors = array();
3065
3066                 if ( $nt->getNamespace() != NS_FILE ) {
3067                         $errors[] = array( 'imagenocrossnamespace' );
3068                 }
3069
3070                 $file = wfLocalFile( $this );
3071                 if ( $file->exists() ) {
3072                         if ( $nt->getText() != wfStripIllegalFilenameChars( $nt->getText() ) ) {
3073                                 $errors[] = array( 'imageinvalidfilename' );
3074                         }
3075                         if ( !File::checkExtensionCompatibility( $file, $nt->getDBkey() ) ) {
3076                                 $errors[] = array( 'imagetypemismatch' );
3077                         }
3078                 }
3079
3080                 $destFile = wfLocalFile( $nt );
3081                 if ( !$wgUser->isAllowed( 'reupload-shared' ) && !$destfile->exists() && wfFindFile( $nt ) ) {
3082                         $errors[] = array( 'file-exists-sharedrepo' );
3083                 }
3084
3085                 return $errors;
3086         }
3087
3088         /**
3089          * Move a title to a new location
3090          *
3091          * @param $nt Title the new title
3092          * @param $auth Bool indicates whether $wgUser's permissions
3093          *  should be checked
3094          * @param $reason String the reason for the move
3095          * @param $createRedirect Bool Whether to create a redirect from the old title to the new title.
3096          *  Ignored if the user doesn't have the suppressredirect right.
3097          * @return Mixed true on success, getUserPermissionsErrors()-like array on failure
3098          */
3099         public function moveTo( &$nt, $auth = true, $reason = '', $createRedirect = true ) {
3100                 $err = $this->isValidMoveOperation( $nt, $auth, $reason );
3101                 if ( is_array( $err ) ) {
3102                         return $err;
3103                 }
3104
3105                 // If it is a file, move it first. It is done before all other moving stuff is
3106                 // done because it's hard to revert
3107                 $dbw = wfGetDB( DB_MASTER );
3108                 if ( $this->getNamespace() == NS_FILE ) {
3109                         $file = wfLocalFile( $this );
3110                         if ( $file->exists() ) {
3111                                 $status = $file->move( $nt );
3112                                 if ( !$status->isOk() ) {
3113                                         return $status->getErrorsArray();
3114                                 }
3115                         }
3116                 }
3117
3118                 $pageid = $this->getArticleID();
3119                 $protected = $this->isProtected();
3120                 $pageCountChange = ( $createRedirect ? 1 : 0 ) - ( $nt->exists() ? 1 : 0 );
3121
3122                 // Do the actual move
3123                 $err = $this->moveToInternal( $nt, $reason, $createRedirect );
3124                 if ( is_array( $err ) ) {
3125                         return $err;
3126                 }
3127
3128                 $redirid = $this->getArticleID();
3129
3130                 // Refresh the sortkey for this row.  Be careful to avoid resetting
3131                 // cl_timestamp, which may disturb time-based lists on some sites.
3132                 $prefixes = $dbw->select(
3133                         'categorylinks',
3134                         array( 'cl_sortkey_prefix', 'cl_to' ),
3135                         array( 'cl_from' => $pageid ),
3136                         __METHOD__
3137                 );
3138                 foreach ( $prefixes as $prefixRow ) {
3139                         $prefix = $prefixRow->cl_sortkey_prefix;
3140                         $catTo = $prefixRow->cl_to;
3141                         $dbw->update( 'categorylinks',
3142                                 array(
3143                                         'cl_sortkey' => Collation::singleton()->getSortKey(
3144                                                 $nt->getCategorySortkey( $prefix ) ),
3145                                         'cl_timestamp=cl_timestamp' ),
3146                                 array(
3147                                         'cl_from' => $pageid,
3148                                         'cl_to' => $catTo ),
3149                                 __METHOD__
3150                         );
3151                 }
3152
3153                 if ( $protected ) {
3154                         # Protect the redirect title as the title used to be...
3155                         $dbw->insertSelect( 'page_restrictions', 'page_restrictions',
3156                                 array(
3157                                         'pr_page'    => $redirid,
3158                                         'pr_type'    => 'pr_type',
3159                                         'pr_level'   => 'pr_level',
3160                                         'pr_cascade' => 'pr_cascade',
3161                                         'pr_user'    => 'pr_user',
3162                                         'pr_expiry'  => 'pr_expiry'
3163                                 ),
3164                                 array( 'pr_page' => $pageid ),
3165                                 __METHOD__,
3166                                 array( 'IGNORE' )
3167                         );
3168                         # Update the protection log
3169                         $log = new LogPage( 'protect' );
3170                         $comment = wfMsgForContent( 'prot_1movedto2', $this->getPrefixedText(), $nt->getPrefixedText() );
3171                         if ( $reason ) {
3172                                 $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3173                         }
3174                         $log->addEntry( 'move_prot', $nt, $comment, array( $this->getPrefixedText() ) ); // FIXME: $params?
3175                 }
3176
3177                 # Update watchlists
3178                 $oldnamespace = $this->getNamespace() & ~1;
3179                 $newnamespace = $nt->getNamespace() & ~1;
3180                 $oldtitle = $this->getDBkey();
3181                 $newtitle = $nt->getDBkey();
3182
3183                 if ( $oldnamespace != $newnamespace || $oldtitle != $newtitle ) {
3184                         WatchedItem::duplicateEntries( $this, $nt );
3185                 }
3186
3187                 # Update search engine
3188                 $u = new SearchUpdate( $pageid, $nt->getPrefixedDBkey() );
3189                 $u->doUpdate();
3190                 $u = new SearchUpdate( $redirid, $this->getPrefixedDBkey(), '' );
3191                 $u->doUpdate();
3192
3193                 # Update site_stats
3194                 if ( $this->isContentPage() && !$nt->isContentPage() ) {
3195                         # No longer a content page
3196                         # Not viewed, edited, removing
3197                         $u = new SiteStatsUpdate( 0, 1, -1, $pageCountChange );
3198                 } elseif ( !$this->isContentPage() && $nt->isContentPage() ) {
3199                         # Now a content page
3200                         # Not viewed, edited, adding
3201                         $u = new SiteStatsUpdate( 0, 1, + 1, $pageCountChange );
3202                 } elseif ( $pageCountChange ) {
3203                         # Redirect added
3204                         $u = new SiteStatsUpdate( 0, 0, 0, 1 );
3205                 } else {
3206                         # Nothing special
3207                         $u = false;
3208                 }
3209                 if ( $u ) {
3210                         $u->doUpdate();
3211                 }
3212                 # Update message cache for interface messages
3213                 if ( $this->getNamespace() == NS_MEDIAWIKI ) {
3214                         # @bug 17860: old article can be deleted, if this the case,
3215                         # delete it from message cache
3216                         if ( $this->getArticleID() === 0 ) {
3217                                 MessageCache::singleton()->replace( $this->getDBkey(), false );
3218                         } else {
3219                                 $oldarticle = new Article( $this );
3220                                 MessageCache::singleton()->replace( $this->getDBkey(), $oldarticle->getContent() );
3221                         }
3222                 }
3223                 if ( $nt->getNamespace() == NS_MEDIAWIKI ) {
3224                         $newarticle = new Article( $nt );
3225                         MessageCache::singleton()->replace( $nt->getDBkey(), $newarticle->getContent() );
3226                 }
3227
3228                 global $wgUser;
3229                 wfRunHooks( 'TitleMoveComplete', array( &$this, &$nt, &$wgUser, $pageid, $redirid ) );
3230                 return true;
3231         }
3232
3233         /**
3234          * Move page to a title which is either a redirect to the
3235          * source page or nonexistent
3236          *
3237          * @param $nt Title the page to move to, which should be a redirect or nonexistent
3238          * @param $reason String The reason for the move
3239          * @param $createRedirect Bool Whether to leave a redirect at the old title.  Ignored
3240          *   if the user doesn't have the suppressredirect right
3241          */
3242         private function moveToInternal( &$nt, $reason = '', $createRedirect = true ) {
3243                 global $wgUser, $wgContLang;
3244
3245                 $moveOverRedirect = $nt->exists();
3246
3247                 $commentMsg = ( $moveOverRedirect ? '1movedto2_redir' : '1movedto2' );
3248                 $comment = wfMsgForContent( $commentMsg, $this->getPrefixedText(), $nt->getPrefixedText() );
3249
3250                 if ( $reason ) {
3251                         $comment .= wfMsgForContent( 'colon-separator' ) . $reason;
3252                 }
3253                 # Truncate for whole multibyte characters. +5 bytes for ellipsis
3254                 $comment = $wgContLang->truncate( $comment, 250 );
3255
3256                 $oldid = $this->getArticleID();
3257                 $latest = $this->getLatestRevID();
3258
3259                 $oldns = $this->getNamespace();
3260                 $olddbk = $this->getDBkey();
3261
3262                 $dbw = wfGetDB( DB_MASTER );
3263
3264                 if ( $moveOverRedirect ) {
3265                         $rcts = $dbw->timestamp( $nt->getEarliestRevTime() );
3266
3267                         $newid = $nt->getArticleID();
3268                         $newns = $nt->getNamespace();
3269                         $newdbk = $nt->getDBkey();
3270
3271                         # Delete the old redirect. We don't save it to history since
3272                         # by definition if we've got here it's rather uninteresting.
3273                         # We have to remove it so that the next step doesn't trigger
3274                         # a conflict on the unique namespace+title index...
3275                         $dbw->delete( 'page', array( 'page_id' => $newid ), __METHOD__ );
3276                         if ( !$dbw->cascadingDeletes() ) {
3277                                 $dbw->delete( 'revision', array( 'rev_page' => $newid ), __METHOD__ );
3278                                 global $wgUseTrackbacks;
3279                                 if ( $wgUseTrackbacks ) {
3280                                         $dbw->delete( 'trackbacks', array( 'tb_page' => $newid ), __METHOD__ );
3281                                 }
3282                                 $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3283                                 $dbw->delete( 'imagelinks', array( 'il_from' => $newid ), __METHOD__ );
3284                                 $dbw->delete( 'categorylinks', array( 'cl_from' => $newid ), __METHOD__ );
3285                                 $dbw->delete( 'templatelinks', array( 'tl_from' => $newid ), __METHOD__ );
3286                                 $dbw->delete( 'externallinks', array( 'el_from' => $newid ), __METHOD__ );
3287                                 $dbw->delete( 'langlinks', array( 'll_from' => $newid ), __METHOD__ );
3288                                 $dbw->delete( 'redirect', array( 'rd_from' => $newid ), __METHOD__ );
3289                         }
3290                         // If the target page was recently created, it may have an entry in recentchanges still
3291                         $dbw->delete( 'recentchanges',
3292                                 array( 'rc_timestamp' => $rcts, 'rc_namespace' => $newns, 'rc_title' => $newdbk, 'rc_new' => 1 ),
3293                                 __METHOD__
3294                         );
3295                 }
3296
3297                 # Save a null revision in the page's history notifying of the move
3298                 $nullRevision = Revision::newNullRevision( $dbw, $oldid, $comment, true );
3299                 if ( !is_object( $nullRevision ) ) {
3300                         throw new MWException( 'No valid null revision produced in ' . __METHOD__ );
3301                 }
3302                 $nullRevId = $nullRevision->insertOn( $dbw );
3303
3304                 $article = new Article( $this );
3305                 wfRunHooks( 'NewRevisionFromEditComplete', array( $article, $nullRevision, $latest, $wgUser ) );
3306
3307                 # Change the name of the target page:
3308                 $dbw->update( 'page',
3309                         /* SET */ array(
3310                                 'page_touched'   => $dbw->timestamp(),
3311                                 'page_namespace' => $nt->getNamespace(),
3312                                 'page_title'     => $nt->getDBkey(),
3313                                 'page_latest'    => $nullRevId,
3314                         ),
3315                         /* WHERE */ array( 'page_id' => $oldid ),
3316                         __METHOD__
3317                 );
3318                 $nt->resetArticleID( $oldid );
3319
3320                 # Recreate the redirect, this time in the other direction.
3321                 if ( $createRedirect || !$wgUser->isAllowed( 'suppressredirect' ) ) {
3322                         $mwRedir = MagicWord::get( 'redirect' );
3323                         $redirectText = $mwRedir->getSynonym( 0 ) . ' [[' . $nt->getPrefixedText() . "]]\n";
3324                         $redirectArticle = new Article( $this );
3325                         $newid = $redirectArticle->insertOn( $dbw );
3326                         $redirectRevision = new Revision( array(
3327                                 'page'    => $newid,
3328                                 'comment' => $comment,
3329                                 'text'    => $redirectText ) );
3330                         $redirectRevision->insertOn( $dbw );
3331                         $redirectArticle->updateRevisionOn( $dbw, $redirectRevision, 0 );
3332
3333                         wfRunHooks( 'NewRevisionFromEditComplete', array( $redirectArticle, $redirectRevision, false, $wgUser ) );
3334
3335                         # Now, we record the link from the redirect to the new title.
3336                         # It should have no other outgoing links...
3337                         $dbw->delete( 'pagelinks', array( 'pl_from' => $newid ), __METHOD__ );
3338                         $dbw->insert( 'pagelinks',
3339                                 array(
3340                                         'pl_from'      => $newid,
3341                                         'pl_namespace' => $nt->getNamespace(),
3342                                         'pl_title'     => $nt->getDBkey() ),
3343                                 __METHOD__ );
3344                         $redirectSuppressed = false;
3345                 } else {
3346                         // Get rid of old new page entries in Special:NewPages and RC.
3347                         // Needs to be before $this->resetArticleUD( 0 ).
3348                         $dbw->delete( 'recentchanges', array(
3349                                         'rc_timestamp' => $dbw->timestamp( $this->getEarliestRevTime() ),
3350                                         'rc_namespace' => $oldns,
3351                                         'rc_title' => $olddbk,
3352                                         'rc_new' => 1
3353                                 ),
3354                                 __METHOD__
3355                         );
3356
3357                         $this->resetArticleID( 0 );
3358                         $redirectSuppressed = true;
3359                 }
3360
3361                 # Log the move
3362                 $log = new LogPage( 'move' );
3363                 $logType = ( $moveOverRedirect ? 'move_redir' : 'move' );
3364                 $log->addEntry( $logType, $this, $reason, array( 1 => $nt->getPrefixedText(), 2 => $redirectSuppressed ) );
3365
3366                 # Purge caches for old and new titles
3367                 if ( $moveOverRedirect ) {
3368                         # A simple purge is enough when moving over a redirect
3369                         $nt->purgeSquid();
3370                 } else {
3371                         # Purge caches as per article creation, including any pages that link to this title
3372                         Article::onArticleCreate( $nt );
3373                 }
3374                 $this->purgeSquid();
3375         }
3376
3377         /**
3378          * Move this page's subpages to be subpages of $nt
3379          *
3380          * @param $nt Title Move target
3381          * @param $auth bool Whether $wgUser's permissions should be checked
3382          * @param $reason string The reason for the move
3383          * @param $createRedirect bool Whether to create redirects from the old subpages to
3384          *     the new ones Ignored if the user doesn't have the 'suppressredirect' right
3385          * @return mixed array with old page titles as keys, and strings (new page titles) or
3386          *     arrays (errors) as values, or an error array with numeric indices if no pages
3387          *     were moved
3388          */
3389         public function moveSubpages( $nt, $auth = true, $reason = '', $createRedirect = true ) {
3390                 global $wgMaximumMovedPages;
3391                 // Check permissions
3392                 if ( !$this->userCan( 'move-subpages' ) ) {
3393                         return array( 'cant-move-subpages' );
3394                 }
3395                 // Do the source and target namespaces support subpages?
3396                 if ( !MWNamespace::hasSubpages( $this->getNamespace() ) ) {
3397                         return array( 'namespace-nosubpages',
3398                                 MWNamespace::getCanonicalName( $this->getNamespace() ) );
3399                 }
3400                 if ( !MWNamespace::hasSubpages( $nt->getNamespace() ) ) {
3401                         return array( 'namespace-nosubpages',
3402                                 MWNamespace::getCanonicalName( $nt->getNamespace() ) );
3403                 }
3404
3405                 $subpages = $this->getSubpages( $wgMaximumMovedPages + 1 );
3406                 $retval = array();
3407                 $count = 0;
3408                 foreach ( $subpages as $oldSubpage ) {
3409                         $count++;
3410                         if ( $count > $wgMaximumMovedPages ) {
3411                                 $retval[$oldSubpage->getPrefixedTitle()] =
3412                                                 array( 'movepage-max-pages',
3413                                                         $wgMaximumMovedPages );
3414                                 break;
3415                         }
3416
3417                         // We don't know whether this function was called before
3418                         // or after moving the root page, so check both
3419                         // $this and $nt
3420                         if ( $oldSubpage->getArticleId() == $this->getArticleId() ||
3421                                         $oldSubpage->getArticleID() == $nt->getArticleId() )
3422                         {
3423                                 // When moving a page to a subpage of itself,
3424                                 // don't move it twice
3425                                 continue;
3426                         }
3427                         $newPageName = preg_replace(
3428                                         '#^' . preg_quote( $this->getDBkey(), '#' ) . '#',
3429                                         StringUtils::escapeRegexReplacement( $nt->getDBkey() ), # bug 21234
3430                                         $oldSubpage->getDBkey() );
3431                         if ( $oldSubpage->isTalkPage() ) {
3432                                 $newNs = $nt->getTalkPage()->getNamespace();
3433                         } else {
3434                                 $newNs = $nt->getSubjectPage()->getNamespace();
3435                         }
3436                         # Bug 14385: we need makeTitleSafe because the new page names may
3437                         # be longer than 255 characters.
3438                         $newSubpage = Title::makeTitleSafe( $newNs, $newPageName );
3439
3440                         $success = $oldSubpage->moveTo( $newSubpage, $auth, $reason, $createRedirect );
3441                         if ( $success === true ) {
3442                                 $retval[$oldSubpage->getPrefixedText()] = $newSubpage->getPrefixedText();
3443                         } else {
3444                                 $retval[$oldSubpage->getPrefixedText()] = $success;
3445                         }
3446                 }
3447                 return $retval;
3448         }
3449
3450         /**
3451          * Checks if this page is just a one-rev redirect.
3452          * Adds lock, so don't use just for light purposes.
3453          *
3454          * @return Bool
3455          */
3456         public function isSingleRevRedirect() {
3457                 $dbw = wfGetDB( DB_MASTER );
3458                 # Is it a redirect?
3459                 $row = $dbw->selectRow( 'page',
3460                         array( 'page_is_redirect', 'page_latest', 'page_id' ),
3461                         $this->pageCond(),
3462                         __METHOD__,
3463                         array( 'FOR UPDATE' )
3464                 );
3465                 # Cache some fields we may want
3466                 $this->mArticleID = $row ? intval( $row->page_id ) : 0;
3467                 $this->mRedirect = $row ? (bool)$row->page_is_redirect : false;
3468                 $this->mLatestID = $row ? intval( $row->page_latest ) : false;
3469                 if ( !$this->mRedirect ) {
3470                         return false;
3471                 }
3472                 # Does the article have a history?
3473                 $row = $dbw->selectField( array( 'page', 'revision' ),
3474                         'rev_id',
3475                         array( 'page_namespace' => $this->getNamespace(),
3476                                 'page_title' => $this->getDBkey(),
3477                                 'page_id=rev_page',
3478                                 'page_latest != rev_id'
3479                         ),
3480                         __METHOD__,
3481                         array( 'FOR UPDATE' )
3482                 );
3483                 # Return true if there was no history
3484                 return ( $row === false );
3485         }
3486
3487         /**
3488          * Checks if $this can be moved to a given Title
3489          * - Selects for update, so don't call it unless you mean business
3490          *
3491          * @param $nt Title the new title to check
3492          * @return Bool
3493          */
3494         public function isValidMoveTarget( $nt ) {
3495                 # Is it an existing file?
3496                 if ( $nt->getNamespace() == NS_FILE ) {
3497                         $file = wfLocalFile( $nt );
3498                         if ( $file->exists() ) {
3499                                 wfDebug( __METHOD__ . ": file exists\n" );
3500                                 return false;
3501                         }
3502                 }
3503                 # Is it a redirect with no history?
3504                 if ( !$nt->isSingleRevRedirect() ) {
3505                         wfDebug( __METHOD__ . ": not a one-rev redirect\n" );
3506                         return false;
3507                 }
3508                 # Get the article text
3509                 $rev = Revision::newFromTitle( $nt );
3510                 $text = $rev->getText();
3511                 # Does the redirect point to the source?
3512                 # Or is it a broken self-redirect, usually caused by namespace collisions?
3513                 $m = array();
3514                 if ( preg_match( "/\\[\\[\\s*([^\\]\\|]*)]]/", $text, $m ) ) {
3515                         $redirTitle = Title::newFromText( $m[1] );
3516                         if ( !is_object( $redirTitle ) ||
3517                                 ( $redirTitle->getPrefixedDBkey() != $this->getPrefixedDBkey() &&
3518                                 $redirTitle->getPrefixedDBkey() != $nt->getPrefixedDBkey() ) ) {
3519                                 wfDebug( __METHOD__ . ": redirect points to other page\n" );
3520                                 return false;
3521                         }
3522                 } else {
3523                         # Fail safe
3524                         wfDebug( __METHOD__ . ": failsafe\n" );
3525                         return false;
3526                 }
3527                 return true;
3528         }
3529
3530         /**
3531          * Can this title be added to a user's watchlist?
3532          *
3533          * @return Bool TRUE or FALSE
3534          */
3535         public function isWatchable() {
3536                 return !$this->isExternal() && MWNamespace::isWatchable( $this->getNamespace() );
3537         }
3538
3539         /**
3540          * Get categories to which this Title belongs and return an array of
3541          * categories' names.
3542          *
3543          * @return Array of parents in the form:
3544          *        $parent => $currentarticle
3545          */
3546         public function getParentCategories() {
3547                 global $wgContLang;
3548
3549                 $data = array();
3550
3551                 $titleKey = $this->getArticleId();
3552
3553                 if ( $titleKey === 0 ) {
3554                         return $data;
3555                 }
3556
3557                 $dbr = wfGetDB( DB_SLAVE );
3558
3559                 $res = $dbr->select( 'categorylinks', '*',
3560                         array(
3561                                 'cl_from' => $titleKey,
3562                         ),
3563                         __METHOD__,
3564                         array()
3565                 );
3566
3567                 if ( $dbr->numRows( $res ) > 0 ) {
3568                         foreach ( $res as $row ) {
3569                                 // $data[] = Title::newFromText($wgContLang->getNSText ( NS_CATEGORY ).':'.$row->cl_to);
3570                                 $data[$wgContLang->getNSText( NS_CATEGORY ) . ':' . $row->cl_to] = $this->getFullText();
3571                         }
3572                 }
3573                 return $data;
3574         }
3575
3576         /**
3577          * Get a tree of parent categories
3578          *
3579          * @param $children Array with the children in the keys, to check for circular refs
3580          * @return Array Tree of parent categories
3581          */
3582         public function getParentCategoryTree( $children = array() ) {
3583                 $stack = array();
3584                 $parents = $this->getParentCategories();
3585
3586                 if ( $parents ) {
3587                         foreach ( $parents as $parent => $current ) {
3588                                 if ( array_key_exists( $parent, $children ) ) {
3589                                         # Circular reference
3590                                         $stack[$parent] = array();
3591                                 } else {
3592                                         $nt = Title::newFromText( $parent );
3593                                         if ( $nt ) {
3594                                                 $stack[$parent] = $nt->getParentCategoryTree( $children + array( $parent => 1 ) );
3595                                         }
3596                                 }
3597                         }
3598                 }
3599
3600                 return $stack;
3601         }
3602
3603         /**
3604          * Get an associative array for selecting this title from
3605          * the "page" table
3606          *
3607          * @return Array suitable for the $where parameter of DB::select()
3608          */
3609         public function pageCond() {
3610                 if ( $this->mArticleID > 0 ) {
3611                         // PK avoids secondary lookups in InnoDB, shouldn't hurt other DBs
3612                         return array( 'page_id' => $this->mArticleID );
3613                 } else {
3614                         return array( 'page_namespace' => $this->mNamespace, 'page_title' => $this->mDbkeyform );
3615                 }
3616         }
3617
3618         /**
3619          * Get the revision ID of the previous revision
3620          *
3621          * @param $revId Int Revision ID. Get the revision that was before this one.
3622          * @param $flags Int Title::GAID_FOR_UPDATE
3623          * @return Int|Bool Old revision ID, or FALSE if none exists
3624          */
3625         public function getPreviousRevisionID( $revId, $flags = 0 ) {
3626                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3627                 return $db->selectField( 'revision', 'rev_id',
3628                         array(
3629                                 'rev_page' => $this->getArticleId( $flags ),
3630                                 'rev_id < ' . intval( $revId )
3631                         ),
3632                         __METHOD__,
3633                         array( 'ORDER BY' => 'rev_id DESC' )
3634                 );
3635         }
3636
3637         /**
3638          * Get the revision ID of the next revision
3639          *
3640          * @param $revId Int Revision ID. Get the revision that was after this one.
3641          * @param $flags Int Title::GAID_FOR_UPDATE
3642          * @return Int|Bool Next revision ID, or FALSE if none exists
3643          */
3644         public function getNextRevisionID( $revId, $flags = 0 ) {
3645                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3646                 return $db->selectField( 'revision', 'rev_id',
3647                         array(
3648                                 'rev_page' => $this->getArticleId( $flags ),
3649                                 'rev_id > ' . intval( $revId )
3650                         ),
3651                         __METHOD__,
3652                         array( 'ORDER BY' => 'rev_id' )
3653                 );
3654         }
3655
3656         /**
3657          * Get the first revision of the page
3658          *
3659          * @param $flags Int Title::GAID_FOR_UPDATE
3660          * @return Revision|Null if page doesn't exist
3661          */
3662         public function getFirstRevision( $flags = 0 ) {
3663                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3664                 $pageId = $this->getArticleId( $flags );
3665                 if ( !$pageId ) {
3666                         return null;
3667                 }
3668                 $row = $db->selectRow( 'revision', '*',
3669                         array( 'rev_page' => $pageId ),
3670                         __METHOD__,
3671                         array( 'ORDER BY' => 'rev_timestamp ASC', 'LIMIT' => 1 )
3672                 );
3673                 if ( !$row ) {
3674                         return null;
3675                 } else {
3676                         return new Revision( $row );
3677                 }
3678         }
3679
3680         /**
3681          * Check if this is a new page
3682          *
3683          * @return bool
3684          */
3685         public function isNewPage() {
3686                 $dbr = wfGetDB( DB_SLAVE );
3687                 return (bool)$dbr->selectField( 'page', 'page_is_new', $this->pageCond(), __METHOD__ );
3688         }
3689
3690         /**
3691          * Get the oldest revision timestamp of this page
3692          *
3693          * @return String: MW timestamp
3694          */
3695         public function getEarliestRevTime() {
3696                 $dbr = wfGetDB( DB_SLAVE );
3697                 if ( $this->exists() ) {
3698                         $min = $dbr->selectField( 'revision',
3699                                 'MIN(rev_timestamp)',
3700                                 array( 'rev_page' => $this->getArticleId() ),
3701                                 __METHOD__ );
3702                         return wfTimestampOrNull( TS_MW, $min );
3703                 }
3704                 return null;
3705         }
3706
3707         /**
3708          * Get the number of revisions between the given revision IDs.
3709          * Used for diffs and other things that really need it.
3710          *
3711          * @param $old Int Revision ID.
3712          * @param $new Int Revision ID.
3713          * @return Int Number of revisions between these IDs.
3714          */
3715         public function countRevisionsBetween( $old, $new ) {
3716                 $dbr = wfGetDB( DB_SLAVE );
3717                 return (int)$dbr->selectField( 'revision', 'count(*)', array(
3718                                 'rev_page' => intval( $this->getArticleId() ),
3719                                 'rev_id > ' . intval( $old ),
3720                                 'rev_id < ' . intval( $new )
3721                         ), __METHOD__
3722                 );
3723         }
3724
3725         /**
3726          * Get the number of authors between the given revision IDs.
3727          * Used for diffs and other things that really need it.
3728          *
3729          * @param $fromRevId Int Revision ID (first before range)
3730          * @param $toRevId Int Revision ID (first after range)
3731          * @param $limit Int Maximum number of authors
3732          * @param $flags Int Title::GAID_FOR_UPDATE
3733          * @return Int
3734          */
3735         public function countAuthorsBetween( $fromRevId, $toRevId, $limit, $flags = 0 ) {
3736                 $db = ( $flags & self::GAID_FOR_UPDATE ) ? wfGetDB( DB_MASTER ) : wfGetDB( DB_SLAVE );
3737                 $res = $db->select( 'revision', 'DISTINCT rev_user_text',
3738                         array(
3739                                 'rev_page' => $this->getArticleID(),
3740                                 'rev_id > ' . (int)$fromRevId,
3741                                 'rev_id < ' . (int)$toRevId
3742                         ), __METHOD__,
3743                         array( 'LIMIT' => $limit )
3744                 );
3745                 return (int)$db->numRows( $res );
3746         }
3747
3748         /**
3749          * Compare with another title.
3750          *
3751          * @param $title Title
3752          * @return Bool
3753          */
3754         public function equals( Title $title ) {
3755                 // Note: === is necessary for proper matching of number-like titles.
3756                 return $this->getInterwiki() === $title->getInterwiki()
3757                         && $this->getNamespace() == $title->getNamespace()
3758                         && $this->getDBkey() === $title->getDBkey();
3759         }
3760
3761         /**
3762          * Callback for usort() to do title sorts by (namespace, title)
3763          *
3764          * @param $a Title
3765          * @param $b Title
3766          *
3767          * @return Integer: result of string comparison, or namespace comparison
3768          */
3769         public static function compare( $a, $b ) {
3770                 if ( $a->getNamespace() == $b->getNamespace() ) {
3771                         return strcmp( $a->getText(), $b->getText() );
3772                 } else {
3773                         return $a->getNamespace() - $b->getNamespace();
3774                 }
3775         }
3776
3777         /**
3778          * Return a string representation of this title
3779          *
3780          * @return String representation of this title
3781          */
3782         public function __toString() {
3783                 return $this->getPrefixedText();
3784         }
3785
3786         /**
3787          * Check if page exists.  For historical reasons, this function simply
3788          * checks for the existence of the title in the page table, and will
3789          * thus return false for interwiki links, special pages and the like.
3790          * If you want to know if a title can be meaningfully viewed, you should
3791          * probably call the isKnown() method instead.
3792          *
3793          * @return Bool
3794          */
3795         public function exists() {
3796                 return $this->getArticleId() != 0;
3797         }
3798
3799         /**
3800          * Should links to this title be shown as potentially viewable (i.e. as
3801          * "bluelinks"), even if there's no record by this title in the page
3802          * table?
3803          *
3804          * This function is semi-deprecated for public use, as well as somewhat
3805          * misleadingly named.  You probably just want to call isKnown(), which
3806          * calls this function internally.
3807          *
3808          * (ISSUE: Most of these checks are cheap, but the file existence check
3809          * can potentially be quite expensive.  Including it here fixes a lot of
3810          * existing code, but we might want to add an optional parameter to skip
3811          * it and any other expensive checks.)
3812          *
3813          * @return Bool
3814          */
3815         public function isAlwaysKnown() {
3816                 if ( $this->mInterwiki != '' ) {
3817                         return true;  // any interwiki link might be viewable, for all we know
3818                 }
3819                 switch( $this->mNamespace ) {
3820                         case NS_MEDIA:
3821                         case NS_FILE:
3822                                 // file exists, possibly in a foreign repo
3823                                 return (bool)wfFindFile( $this );
3824                         case NS_SPECIAL:
3825                                 // valid special page
3826                                 return SpecialPage::exists( $this->getDBkey() );
3827                         case NS_MAIN:
3828                                 // selflink, possibly with fragment
3829                                 return $this->mDbkeyform == '';
3830                         case NS_MEDIAWIKI:
3831                                 // known system message
3832                                 return $this->getDefaultMessageText() !== false;
3833                         default:
3834                                 return false;
3835                 }
3836         }
3837
3838         /**
3839          * Does this title refer to a page that can (or might) be meaningfully
3840          * viewed?  In particular, this function may be used to determine if
3841          * links to the title should be rendered as "bluelinks" (as opposed to
3842          * "redlinks" to non-existent pages).
3843          *
3844          * @return Bool
3845          */
3846         public function isKnown() {
3847                 return $this->isAlwaysKnown() || $this->exists();
3848         }
3849
3850         /**
3851          * Does this page have source text?
3852          *
3853          * @return Boolean
3854          */
3855         public function hasSourceText() {
3856                 if ( $this->exists() ) {
3857                         return true;
3858                 }
3859
3860                 if ( $this->mNamespace == NS_MEDIAWIKI ) {
3861                         // If the page doesn't exist but is a known system message, default
3862                         // message content will be displayed, same for language subpages
3863                         return $this->getDefaultMessageText() !== false;
3864                 }
3865
3866                 return false;
3867         }
3868
3869         /**
3870          * Get the default message text or false if the message doesn't exist
3871          *
3872          * @return String or false
3873          */
3874         public function getDefaultMessageText() {
3875                 global $wgContLang;
3876
3877                 if ( $this->getNamespace() != NS_MEDIAWIKI ) { // Just in case
3878                         return false;
3879                 }
3880
3881                 list( $name, $lang ) = MessageCache::singleton()->figureMessage( $wgContLang->lcfirst( $this->getText() ) );
3882                 $message = wfMessage( $name )->inLanguage( $lang )->useDatabase( false );
3883
3884                 if ( $message->exists() ) {
3885                         return $message->plain();
3886                 } else {
3887                         return false;
3888                 }
3889         }
3890
3891         /**
3892          * Is this in a namespace that allows actual pages?
3893          *
3894          * @return Bool
3895          * @internal note -- uses hardcoded namespace index instead of constants
3896          */
3897         public function canExist() {
3898                 return $this->mNamespace >= 0 && $this->mNamespace != NS_MEDIA;
3899         }
3900
3901         /**
3902          * Update page_touched timestamps and send squid purge messages for
3903          * pages linking to this title. May be sent to the job queue depending
3904          * on the number of links. Typically called on create and delete.
3905          */
3906         public function touchLinks() {
3907                 $u = new HTMLCacheUpdate( $this, 'pagelinks' );
3908                 $u->doUpdate();
3909
3910                 if ( $this->getNamespace() == NS_CATEGORY ) {
3911                         $u = new HTMLCacheUpdate( $this, 'categorylinks' );
3912                         $u->doUpdate();
3913                 }
3914         }
3915
3916         /**
3917          * Get the last touched timestamp
3918          *
3919          * @param $db DatabaseBase: optional db
3920          * @return String last-touched timestamp
3921          */
3922         public function getTouched( $db = null ) {
3923                 $db = isset( $db ) ? $db : wfGetDB( DB_SLAVE );
3924                 $touched = $db->selectField( 'page', 'page_touched', $this->pageCond(), __METHOD__ );
3925                 return $touched;
3926         }
3927
3928         /**
3929          * Get the timestamp when this page was updated since the user last saw it.
3930          *
3931          * @param $user User
3932          * @return String|Null
3933          */
3934         public function getNotificationTimestamp( $user = null ) {
3935                 global $wgUser, $wgShowUpdatedMarker;
3936                 // Assume current user if none given
3937                 if ( !$user ) {
3938                         $user = $wgUser;
3939                 }
3940                 // Check cache first
3941                 $uid = $user->getId();
3942                 // avoid isset here, as it'll return false for null entries
3943                 if ( array_key_exists( $uid, $this->mNotificationTimestamp ) ) {
3944                         return $this->mNotificationTimestamp[$uid];
3945                 }
3946                 if ( !$uid || !$wgShowUpdatedMarker ) {
3947                         return $this->mNotificationTimestamp[$uid] = false;
3948                 }
3949                 // Don't cache too much!
3950                 if ( count( $this->mNotificationTimestamp ) >= self::CACHE_MAX ) {
3951                         $this->mNotificationTimestamp = array();
3952                 }
3953                 $dbr = wfGetDB( DB_SLAVE );
3954                 $this->mNotificationTimestamp[$uid] = $dbr->selectField( 'watchlist',
3955                         'wl_notificationtimestamp',
3956                         array( 'wl_namespace' => $this->getNamespace(),
3957                                 'wl_title' => $this->getDBkey(),
3958                                 'wl_user' => $user->getId()
3959                         ),
3960                         __METHOD__
3961                 );
3962                 return $this->mNotificationTimestamp[$uid];
3963         }
3964
3965         /**
3966          * Get the trackback URL for this page
3967          *
3968          * @return String Trackback URL
3969          */
3970         public function trackbackURL() {
3971                 global $wgScriptPath, $wgServer, $wgScriptExtension;
3972
3973                 return "$wgServer$wgScriptPath/trackback$wgScriptExtension?article="
3974                         . htmlspecialchars( urlencode( $this->getPrefixedDBkey() ) );
3975         }
3976
3977         /**
3978          * Get the trackback RDF for this page
3979          *
3980          * @return String Trackback RDF
3981          */
3982         public function trackbackRDF() {
3983                 $url = htmlspecialchars( $this->getFullURL() );
3984                 $title = htmlspecialchars( $this->getText() );
3985                 $tburl = $this->trackbackURL();
3986
3987                 // Autodiscovery RDF is placed in comments so HTML validator
3988                 // won't barf. This is a rather icky workaround, but seems
3989                 // frequently used by this kind of RDF thingy.
3990                 //
3991                 // Spec: http://www.sixapart.com/pronet/docs/trackback_spec
3992                 return "<!--
3993 <rdf:RDF xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\"
3994                  xmlns:dc=\"http://purl.org/dc/elements/1.1/\"
3995                  xmlns:trackback=\"http://madskills.com/public/xml/rss/module/trackback/\">
3996 <rdf:Description
3997    rdf:about=\"$url\"
3998    dc:identifier=\"$url\"
3999    dc:title=\"$title\"
4000    trackback:ping=\"$tburl\" />
4001 </rdf:RDF>
4002 -->";
4003         }
4004
4005         /**
4006          * Generate strings used for xml 'id' names in monobook tabs
4007          *
4008          * @param $prepend string defaults to 'nstab-'
4009          * @return String XML 'id' name
4010          */
4011         public function getNamespaceKey( $prepend = 'nstab-' ) {
4012                 global $wgContLang;
4013                 // Gets the subject namespace if this title
4014                 $namespace = MWNamespace::getSubject( $this->getNamespace() );
4015                 // Checks if cononical namespace name exists for namespace
4016                 if ( MWNamespace::exists( $this->getNamespace() ) ) {
4017                         // Uses canonical namespace name
4018                         $namespaceKey = MWNamespace::getCanonicalName( $namespace );
4019                 } else {
4020                         // Uses text of namespace
4021                         $namespaceKey = $this->getSubjectNsText();
4022                 }
4023                 // Makes namespace key lowercase
4024                 $namespaceKey = $wgContLang->lc( $namespaceKey );
4025                 // Uses main
4026                 if ( $namespaceKey == '' ) {
4027                         $namespaceKey = 'main';
4028                 }
4029                 // Changes file to image for backwards compatibility
4030                 if ( $namespaceKey == 'file' ) {
4031                         $namespaceKey = 'image';
4032                 }
4033                 return $prepend . $namespaceKey;
4034         }
4035
4036         /**
4037          * Returns true if this is a special page.
4038          *
4039          * @return boolean
4040          */
4041         public function isSpecialPage() {
4042                 return $this->getNamespace() == NS_SPECIAL;
4043         }
4044
4045         /**
4046          * Returns true if this title resolves to the named special page
4047          *
4048          * @param $name String The special page name
4049          * @return boolean
4050          */
4051         public function isSpecial( $name ) {
4052                 if ( $this->getNamespace() == NS_SPECIAL ) {
4053                         list( $thisName, /* $subpage */ ) = SpecialPage::resolveAliasWithSubpage( $this->getDBkey() );
4054                         if ( $name == $thisName ) {
4055                                 return true;
4056                         }
4057                 }
4058                 return false;
4059         }
4060
4061         /**
4062          * If the Title refers to a special page alias which is not the local default, resolve
4063          * the alias, and localise the name as necessary.  Otherwise, return $this
4064          *
4065          * @return Title
4066          */
4067         public function fixSpecialName() {
4068                 if ( $this->getNamespace() == NS_SPECIAL ) {
4069                         $canonicalName = SpecialPage::resolveAlias( $this->mDbkeyform );
4070                         if ( $canonicalName ) {
4071                                 $localName = SpecialPage::getLocalNameFor( $canonicalName );
4072                                 if ( $localName != $this->mDbkeyform ) {
4073                                         return Title::makeTitle( NS_SPECIAL, $localName );
4074                                 }
4075                         }
4076                 }
4077                 return $this;
4078         }
4079
4080         /**
4081          * Is this Title in a namespace which contains content?
4082          * In other words, is this a content page, for the purposes of calculating
4083          * statistics, etc?
4084          *
4085          * @return Boolean
4086          */
4087         public function isContentPage() {
4088                 return MWNamespace::isContent( $this->getNamespace() );
4089         }
4090
4091         /**
4092          * Get all extant redirects to this Title
4093          *
4094          * @param $ns Int|Null Single namespace to consider; NULL to consider all namespaces
4095          * @return Array of Title redirects to this title
4096          */
4097         public function getRedirectsHere( $ns = null ) {
4098                 $redirs = array();
4099
4100                 $dbr = wfGetDB( DB_SLAVE );
4101                 $where = array(
4102                         'rd_namespace' => $this->getNamespace(),
4103                         'rd_title' => $this->getDBkey(),
4104                         'rd_from = page_id'
4105                 );
4106                 if ( !is_null( $ns ) ) {
4107                         $where['page_namespace'] = $ns;
4108                 }
4109
4110                 $res = $dbr->select(
4111                         array( 'redirect', 'page' ),
4112                         array( 'page_namespace', 'page_title' ),
4113                         $where,
4114                         __METHOD__
4115                 );
4116
4117                 foreach ( $res as $row ) {
4118                         $redirs[] = self::newFromRow( $row );
4119                 }
4120                 return $redirs;
4121         }
4122
4123         /**
4124          * Check if this Title is a valid redirect target
4125          *
4126          * @return Bool
4127          */
4128         public function isValidRedirectTarget() {
4129                 global $wgInvalidRedirectTargets;
4130
4131                 // invalid redirect targets are stored in a global array, but explicity disallow Userlogout here
4132                 if ( $this->isSpecial( 'Userlogout' ) ) {
4133                         return false;
4134                 }
4135
4136                 foreach ( $wgInvalidRedirectTargets as $target ) {
4137                         if ( $this->isSpecial( $target ) ) {
4138                                 return false;
4139                         }
4140                 }
4141
4142                 return true;
4143         }
4144
4145         /**
4146          * Get a backlink cache object
4147          *
4148          * @return object BacklinkCache
4149          */
4150         function getBacklinkCache() {
4151                 if ( is_null( $this->mBacklinkCache ) ) {
4152                         $this->mBacklinkCache = new BacklinkCache( $this );
4153                 }
4154                 return $this->mBacklinkCache;
4155         }
4156
4157         /**
4158          * Whether the magic words __INDEX__ and __NOINDEX__ function for  this page.
4159          *
4160          * @return Boolean
4161          */
4162         public function canUseNoindex() {
4163                 global $wgContentNamespaces, $wgExemptFromUserRobotsControl;
4164
4165                 $bannedNamespaces = is_null( $wgExemptFromUserRobotsControl )
4166                         ? $wgContentNamespaces
4167                         : $wgExemptFromUserRobotsControl;
4168
4169                 return !in_array( $this->mNamespace, $bannedNamespaces );
4170
4171         }
4172
4173         /**
4174          * Returns restriction types for the current Title
4175          *
4176          * @return array applicable restriction types
4177          */
4178         public function getRestrictionTypes() {
4179                 if ( $this->getNamespace() == NS_SPECIAL ) {
4180                         return array();
4181                 }
4182
4183                 $types = self::getFilteredRestrictionTypes( $this->exists() );
4184
4185                 if ( $this->getNamespace() != NS_FILE ) {
4186                         # Remove the upload restriction for non-file titles
4187                         $types = array_diff( $types, array( 'upload' ) );
4188                 }
4189
4190                 wfRunHooks( 'TitleGetRestrictionTypes', array( $this, &$types ) );
4191
4192                 wfDebug( __METHOD__ . ': applicable restriction types for ' .
4193                         $this->getPrefixedText() . ' are ' . implode( ',', $types ) . "\n" );
4194
4195                 return $types;
4196         }
4197         /**
4198          * Get a filtered list of all restriction types supported by this wiki.
4199          * @param bool $exists True to get all restriction types that apply to
4200          * titles that do exist, False for all restriction types that apply to
4201          * titles that do not exist
4202          * @return array
4203          */
4204         public static function getFilteredRestrictionTypes( $exists = true ) {
4205                 global $wgRestrictionTypes;
4206                 $types = $wgRestrictionTypes;
4207                 if ( $exists ) {
4208                         # Remove the create restriction for existing titles
4209                         $types = array_diff( $types, array( 'create' ) );
4210                 } else {
4211                         # Only the create and upload restrictions apply to non-existing titles
4212                         $types = array_intersect( $types, array( 'create', 'upload' ) );
4213                 }
4214                 return $types;
4215         }
4216
4217         /**
4218          * Returns the raw sort key to be used for categories, with the specified
4219          * prefix.  This will be fed to Collation::getSortKey() to get a
4220          * binary sortkey that can be used for actual sorting.
4221          *
4222          * @param $prefix string The prefix to be used, specified using
4223          *   {{defaultsort:}} or like [[Category:Foo|prefix]].  Empty for no
4224          *   prefix.
4225          * @return string
4226          */
4227         public function getCategorySortkey( $prefix = '' ) {
4228                 $unprefixed = $this->getText();
4229                 if ( $prefix !== '' ) {
4230                         # Separate with a line feed, so the unprefixed part is only used as
4231                         # a tiebreaker when two pages have the exact same prefix.
4232                         # In UCA, tab is the only character that can sort above LF
4233                         # so we strip both of them from the original prefix.
4234                         $prefix = strtr( $prefix, "\n\t", '  ' );
4235                         return "$prefix\n$unprefixed";
4236                 }
4237                 return $unprefixed;
4238         }
4239 }