includes/Title.php

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