includes/specialpage/SpecialPageFactory.php

   1 <?php
   2 /**
   3  * Factory for handling the special page list and generating SpecialPage objects.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup SpecialPage
  22  * @defgroup SpecialPage SpecialPage
  23  */
  24
  25 /**
  26  * Factory for handling the special page list and generating SpecialPage objects.
  27  *
  28  * To add a special page in an extension, add to $wgSpecialPages either
  29  * an object instance or an array containing the name and constructor
  30  * parameters. The latter is preferred for performance reasons.
  31  *
  32  * The object instantiated must be either an instance of SpecialPage or a
  33  * sub-class thereof. It must have an execute() method, which sends the HTML
  34  * for the special page to $wgOut. The parent class has an execute() method
  35  * which distributes the call to the historical global functions. Additionally,
  36  * execute() also checks if the user has the necessary access privileges
  37  * and bails out if not.
  38  *
  39  * To add a core special page, use the similar static list in
  40  * SpecialPageFactory::$list. To remove a core static special page at runtime, use
  41  * a SpecialPage_initList hook.
  42  *
  43  * @ingroup SpecialPage
  44  * @since 1.17
  45  */
  46 class SpecialPageFactory {
  47         /**
  48          * List of special page names to the subclass of SpecialPage which handles them.
  49          */
  50         private static $coreList = array(
  51                 // Maintenance Reports
  52                 'BrokenRedirects' => 'BrokenRedirectsPage',
  53                 'Deadendpages' => 'DeadendPagesPage',
  54                 'DoubleRedirects' => 'DoubleRedirectsPage',
  55                 'Longpages' => 'LongPagesPage',
  56                 'Ancientpages' => 'AncientPagesPage',
  57                 'Lonelypages' => 'LonelyPagesPage',
  58                 'Fewestrevisions' => 'FewestrevisionsPage',
  59                 'Withoutinterwiki' => 'WithoutInterwikiPage',
  60                 'Protectedpages' => 'SpecialProtectedpages',
  61                 'Protectedtitles' => 'SpecialProtectedtitles',
  62                 'Shortpages' => 'ShortPagesPage',
  63                 'Uncategorizedcategories' => 'UncategorizedCategoriesPage',
  64                 'Uncategorizedimages' => 'UncategorizedImagesPage',
  65                 'Uncategorizedpages' => 'UncategorizedPagesPage',
  66                 'Uncategorizedtemplates' => 'UncategorizedTemplatesPage',
  67                 'Unusedcategories' => 'UnusedCategoriesPage',
  68                 'Unusedimages' => 'UnusedimagesPage',
  69                 'Unusedtemplates' => 'UnusedtemplatesPage',
  70                 'Unwatchedpages' => 'UnwatchedpagesPage',
  71                 'Wantedcategories' => 'WantedCategoriesPage',
  72                 'Wantedfiles' => 'WantedFilesPage',
  73                 'Wantedpages' => 'WantedPagesPage',
  74                 'Wantedtemplates' => 'WantedTemplatesPage',
  75
  76                 // List of pages
  77                 'Allpages' => 'SpecialAllPages',
  78                 'Prefixindex' => 'SpecialPrefixindex',
  79                 'Categories' => 'SpecialCategories',
  80                 'Listredirects' => 'ListredirectsPage',
  81                 'PagesWithProp' => 'SpecialPagesWithProp',
  82                 'TrackingCategories' => 'SpecialTrackingCategories',
  83
  84                 // Login/create account
  85                 'Userlogin' => 'LoginForm',
  86                 'CreateAccount' => 'SpecialCreateAccount',
  87
  88                 // Users and rights
  89                 'Block' => 'SpecialBlock',
  90                 'Unblock' => 'SpecialUnblock',
  91                 'BlockList' => 'SpecialBlockList',
  92                 'ChangePassword' => 'SpecialChangePassword',
  93                 'PasswordReset' => 'SpecialPasswordReset',
  94                 'DeletedContributions' => 'DeletedContributionsPage',
  95                 'Preferences' => 'SpecialPreferences',
  96                 'ResetTokens' => 'SpecialResetTokens',
  97                 'Contributions' => 'SpecialContributions',
  98                 'Listgrouprights' => 'SpecialListGroupRights',
  99                 'Listgrants' => 'SpecialListGrants',
 100                 'Listusers' => 'SpecialListUsers',
 101                 'Listadmins' => 'SpecialListAdmins',
 102                 'Listbots' => 'SpecialListBots',
 103                 'Userrights' => 'UserrightsPage',
 104                 'EditWatchlist' => 'SpecialEditWatchlist',
 105
 106                 // Recent changes and logs
 107                 'Newimages' => 'SpecialNewFiles',
 108                 'Log' => 'SpecialLog',
 109                 'Watchlist' => 'SpecialWatchlist',
 110                 'Newpages' => 'SpecialNewpages',
 111                 'Recentchanges' => 'SpecialRecentChanges',
 112                 'Recentchangeslinked' => 'SpecialRecentChangesLinked',
 113                 'Tags' => 'SpecialTags',
 114
 115                 // Media reports and uploads
 116                 'Listfiles' => 'SpecialListFiles',
 117                 'Filepath' => 'SpecialFilepath',
 118                 'MediaStatistics' => 'MediaStatisticsPage',
 119                 'MIMEsearch' => 'MIMEsearchPage',
 120                 'FileDuplicateSearch' => 'FileDuplicateSearchPage',
 121                 'Upload' => 'SpecialUpload',
 122                 'UploadStash' => 'SpecialUploadStash',
 123                 'ListDuplicatedFiles' => 'ListDuplicatedFilesPage',
 124
 125                 // Data and tools
 126                 'Statistics' => 'SpecialStatistics',
 127                 'Allmessages' => 'SpecialAllMessages',
 128                 'Version' => 'SpecialVersion',
 129                 'Lockdb' => 'SpecialLockdb',
 130                 'Unlockdb' => 'SpecialUnlockdb',
 131
 132                 // Redirecting special pages
 133                 'LinkSearch' => 'LinkSearchPage',
 134                 'Randompage' => 'RandomPage',
 135                 'RandomInCategory' => 'SpecialRandomInCategory',
 136                 'Randomredirect' => 'SpecialRandomredirect',
 137                 'Randomrootpage' => 'SpecialRandomrootpage',
 138
 139                 // High use pages
 140                 'Mostlinkedcategories' => 'MostlinkedCategoriesPage',
 141                 'Mostimages' => 'MostimagesPage',
 142                 'Mostinterwikis' => 'MostinterwikisPage',
 143                 'Mostlinked' => 'MostlinkedPage',
 144                 'Mostlinkedtemplates' => 'MostlinkedTemplatesPage',
 145                 'Mostcategories' => 'MostcategoriesPage',
 146                 'Mostrevisions' => 'MostrevisionsPage',
 147
 148                 // Page tools
 149                 'ComparePages' => 'SpecialComparePages',
 150                 'Export' => 'SpecialExport',
 151                 'Import' => 'SpecialImport',
 152                 'Undelete' => 'SpecialUndelete',
 153                 'Whatlinkshere' => 'SpecialWhatLinksHere',
 154                 'MergeHistory' => 'SpecialMergeHistory',
 155                 'ExpandTemplates' => 'SpecialExpandTemplates',
 156
 157                 // Other
 158                 'Booksources' => 'SpecialBookSources',
 159
 160                 // Unlisted / redirects
 161                 'ApiHelp' => 'SpecialApiHelp',
 162                 'Blankpage' => 'SpecialBlankpage',
 163                 'Diff' => 'SpecialDiff',
 164                 'EditTags' => 'SpecialEditTags',
 165                 'Emailuser' => 'SpecialEmailUser',
 166                 'Movepage' => 'MovePageForm',
 167                 'Mycontributions' => 'SpecialMycontributions',
 168                 'MyLanguage' => 'SpecialMyLanguage',
 169                 'Mypage' => 'SpecialMypage',
 170                 'Mytalk' => 'SpecialMytalk',
 171                 'Myuploads' => 'SpecialMyuploads',
 172                 'AllMyUploads' => 'SpecialAllMyUploads',
 173                 'PermanentLink' => 'SpecialPermanentLink',
 174                 'Redirect' => 'SpecialRedirect',
 175                 'Revisiondelete' => 'SpecialRevisionDelete',
 176                 'RunJobs' => 'SpecialRunJobs',
 177                 'Specialpages' => 'SpecialSpecialpages',
 178                 'Userlogout' => 'SpecialUserlogout',
 179         );
 180
 181         private static $list;
 182         private static $aliases;
 183
 184         /**
 185          * Reset the internal list of special pages. Useful when changing $wgSpecialPages after
 186          * the internal list has already been initialized, e.g. during testing.
 187          */
 188         public static function resetList() {
 189                 self::$list = null;
 190                 self::$aliases = null;
 191         }
 192
 193         /**
 194          * Returns a list of canonical special page names.
 195          * May be used to iterate over all registered special pages.
 196          *
 197          * @return string[]
 198          */
 199         public static function getNames() {
 200                 return array_keys( self::getPageList() );
 201         }
 202
 203         /**
 204          * Get the special page list as an array
 205          *
 206          * @deprecated since 1.24, use getNames() instead.
 207          * @return array
 208          */
 209         public static function getList() {
 210                 wfDeprecated( __FUNCTION__, '1.24' );
 211                 return self::getPageList();
 212         }
 213
 214         /**
 215          * Get the special page list as an array
 216          *
 217          * @return array
 218          */
 219         private static function getPageList() {
 220                 global $wgSpecialPages;
 221                 global $wgDisableInternalSearch, $wgEmailAuthentication;
 222                 global $wgEnableEmail, $wgEnableJavaScriptTest;
 223                 global $wgPageLanguageUseDB, $wgContentHandlerUseDB;
 224
 225                 if ( !is_array( self::$list ) ) {
 226
 227                         self::$list = self::$coreList;
 228
 229                         if ( !$wgDisableInternalSearch ) {
 230                                 self::$list['Search'] = 'SpecialSearch';
 231                         }
 232
 233                         if ( $wgEmailAuthentication ) {
 234                                 self::$list['Confirmemail'] = 'EmailConfirmation';
 235                                 self::$list['Invalidateemail'] = 'EmailInvalidation';
 236                         }
 237
 238                         if ( $wgEnableEmail ) {
 239                                 self::$list['ChangeEmail'] = 'SpecialChangeEmail';
 240                         }
 241
 242                         if ( $wgEnableJavaScriptTest ) {
 243                                 self::$list['JavaScriptTest'] = 'SpecialJavaScriptTest';
 244                         }
 245
 246                         if ( $wgPageLanguageUseDB ) {
 247                                 self::$list['PageLanguage'] = 'SpecialPageLanguage';
 248                         }
 249                         if ( $wgContentHandlerUseDB ) {
 250                                 self::$list['ChangeContentModel'] = 'SpecialChangeContentModel';
 251                         }
 252
 253                         self::$list['Activeusers'] = 'SpecialActiveUsers';
 254
 255                         // Add extension special pages
 256                         self::$list = array_merge( self::$list, $wgSpecialPages );
 257
 258                         // This hook can be used to disable unwanted core special pages
 259                         // or conditionally register special pages.
 260                         Hooks::run( 'SpecialPage_initList', array( &self::$list ) );
 261
 262                 }
 263
 264                 return self::$list;
 265         }
 266
 267         /**
 268          * Initialise and return the list of special page aliases. Returns an array where
 269          * the key is an alias, and the value is the canonical name of the special page.
 270          * All registered special pages are guaranteed to map to themselves.
 271          * @return array
 272          */
 273         private static function getAliasList() {
 274                 if ( is_null( self::$aliases ) ) {
 275                         global $wgContLang;
 276                         $aliases = $wgContLang->getSpecialPageAliases();
 277                         $pageList = self::getPageList();
 278
 279                         self::$aliases = array();
 280                         $keepAlias = array();
 281
 282                         // Force every canonical name to be an alias for itself.
 283                         foreach ( $pageList as $name => $stuff ) {
 284                                 $caseFoldedAlias = $wgContLang->caseFold( $name );
 285                                 self::$aliases[$caseFoldedAlias] = $name;
 286                                 $keepAlias[$caseFoldedAlias] = 'canonical';
 287                         }
 288
 289                         // Check for $aliases being an array since Language::getSpecialPageAliases can return null
 290                         if ( is_array( $aliases ) ) {
 291                                 foreach ( $aliases as $realName => $aliasList ) {
 292                                         $aliasList = array_values( $aliasList );
 293                                         foreach ( $aliasList as $i => $alias ) {
 294                                                 $caseFoldedAlias = $wgContLang->caseFold( $alias );
 295
 296                                                 if ( isset( self::$aliases[$caseFoldedAlias] ) &&
 297                                                         $realName === self::$aliases[$caseFoldedAlias]
 298                                                 ) {
 299                                                         // Ignore same-realName conflicts
 300                                                         continue;
 301                                                 }
 302
 303                                                 if ( !isset( $keepAlias[$caseFoldedAlias] ) ) {
 304                                                         self::$aliases[$caseFoldedAlias] = $realName;
 305                                                         if ( !$i ) {
 306                                                                 $keepAlias[$caseFoldedAlias] = 'first';
 307                                                         }
 308                                                 } elseif ( !$i ) {
 309                                                         wfWarn( "First alias '$alias' for $realName conflicts with " .
 310                                                                 "{$keepAlias[$caseFoldedAlias]} alias for " .
 311                                                                 self::$aliases[$caseFoldedAlias]
 312                                                         );
 313                                                 }
 314                                         }
 315                                 }
 316                         }
 317                 }
 318
 319                 return self::$aliases;
 320         }
 321
 322         /**
 323          * Given a special page name with a possible subpage, return an array
 324          * where the first element is the special page name and the second is the
 325          * subpage.
 326          *
 327          * @param string $alias
 328          * @return array Array( String, String|null ), or array( null, null ) if the page is invalid
 329          */
 330         public static function resolveAlias( $alias ) {
 331                 global $wgContLang;
 332                 $bits = explode( '/', $alias, 2 );
 333
 334                 $caseFoldedAlias = $wgContLang->caseFold( $bits[0] );
 335                 $caseFoldedAlias = str_replace( ' ', '_', $caseFoldedAlias );
 336                 $aliases = self::getAliasList();
 337                 if ( isset( $aliases[$caseFoldedAlias] ) ) {
 338                         $name = $aliases[$caseFoldedAlias];
 339                 } else {
 340                         return array( null, null );
 341                 }
 342
 343                 if ( !isset( $bits[1] ) ) { // bug 2087
 344                         $par = null;
 345                 } else {
 346                         $par = $bits[1];
 347                 }
 348
 349                 return array( $name, $par );
 350         }
 351
 352         /**
 353          * Check if a given name exist as a special page or as a special page alias
 354          *
 355          * @param string $name Name of a special page
 356          * @return bool True if a special page exists with this name
 357          */
 358         public static function exists( $name ) {
 359                 list( $title, /*...*/ ) = self::resolveAlias( $name );
 360
 361                 $specialPageList = self::getPageList();
 362                 return isset( $specialPageList[$title] );
 363         }
 364
 365         /**
 366          * Find the object with a given name and return it (or NULL)
 367          *
 368          * @param string $name Special page name, may be localised and/or an alias
 369          * @return SpecialPage|null SpecialPage object or null if the page doesn't exist
 370          */
 371         public static function getPage( $name ) {
 372                 list( $realName, /*...*/ ) = self::resolveAlias( $name );
 373
 374                 $specialPageList = self::getPageList();
 375
 376                 if ( isset( $specialPageList[$realName] ) ) {
 377                         $rec = $specialPageList[$realName];
 378
 379                         if ( is_callable( $rec ) ) {
 380                                 // Use callback to instantiate the special page
 381                                 $page = call_user_func( $rec );
 382                         } elseif ( is_string( $rec ) ) {
 383                                 $className = $rec;
 384                                 $page = new $className;
 385                         } elseif ( is_array( $rec ) ) {
 386                                 $className = array_shift( $rec );
 387                                 // @deprecated, officially since 1.18, unofficially since forever
 388                                 wfDeprecated( "Array syntax for \$wgSpecialPages is deprecated ($className), " .
 389                                         "define a subclass of SpecialPage instead.", '1.18' );
 390                                 $page = ObjectFactory::getObjectFromSpec( array(
 391                                         'class' => $className,
 392                                         'args' => $rec,
 393                                         'closure_expansion' => false,
 394                                 ) );
 395                         } elseif ( $rec instanceof SpecialPage ) {
 396                                 $page = $rec; // XXX: we should deep clone here
 397                         } else {
 398                                 $page = null;
 399                         }
 400
 401                         if ( $page instanceof SpecialPage ) {
 402                                 return $page;
 403                         } else {
 404                                 // It's not a classname, nor a callback, nor a legacy constructor array,
 405                                 // nor a special page object. Give up.
 406                                 wfLogWarning( "Cannot instantiate special page $realName: bad spec!" );
 407                                 return null;
 408                         }
 409
 410                 } else {
 411                         return null;
 412                 }
 413         }
 414
 415         /**
 416          * Return categorised listable special pages which are available
 417          * for the current user, and everyone.
 418          *
 419          * @param User $user User object to check permissions, $wgUser will be used
 420          *        if not provided
 421          * @return array ( string => Specialpage )
 422          */
 423         public static function getUsablePages( User $user = null ) {
 424                 $pages = array();
 425                 if ( $user === null ) {
 426                         global $wgUser;
 427                         $user = $wgUser;
 428                 }
 429                 foreach ( self::getPageList() as $name => $rec ) {
 430                         $page = self::getPage( $name );
 431                         if ( $page ) { // not null
 432                                 $page->setContext( RequestContext::getMain() );
 433                                 if ( $page->isListed()
 434                                         && ( !$page->isRestricted() || $page->userCanExecute( $user ) )
 435                                 ) {
 436                                         $pages[$name] = $page;
 437                                 }
 438                         }
 439                 }
 440
 441                 return $pages;
 442         }
 443
 444         /**
 445          * Return categorised listable special pages for all users
 446          *
 447          * @return array ( string => Specialpage )
 448          */
 449         public static function getRegularPages() {
 450                 $pages = array();
 451                 foreach ( self::getPageList() as $name => $rec ) {
 452                         $page = self::getPage( $name );
 453                         if ( $page->isListed() && !$page->isRestricted() ) {
 454                                 $pages[$name] = $page;
 455                         }
 456                 }
 457
 458                 return $pages;
 459         }
 460
 461         /**
 462          * Return categorised listable special pages which are available
 463          * for the current user, but not for everyone
 464          *
 465          * @param User|null $user User object to use or null for $wgUser
 466          * @return array ( string => Specialpage )
 467          */
 468         public static function getRestrictedPages( User $user = null ) {
 469                 $pages = array();
 470                 if ( $user === null ) {
 471                         global $wgUser;
 472                         $user = $wgUser;
 473                 }
 474                 foreach ( self::getPageList() as $name => $rec ) {
 475                         $page = self::getPage( $name );
 476                         if (
 477                                 $page->isListed()
 478                                 && $page->isRestricted()
 479                                 && $page->userCanExecute( $user )
 480                         ) {
 481                                 $pages[$name] = $page;
 482                         }
 483                 }
 484
 485                 return $pages;
 486         }
 487
 488         /**
 489          * Execute a special page path.
 490          * The path may contain parameters, e.g. Special:Name/Params
 491          * Extracts the special page name and call the execute method, passing the parameters
 492          *
 493          * Returns a title object if the page is redirected, false if there was no such special
 494          * page, and true if it was successful.
 495          *
 496          * @param Title $title
 497          * @param IContextSource $context
 498          * @param bool $including Bool output is being captured for use in {{special:whatever}}
 499          *
 500          * @return bool
 501          */
 502         public static function executePath( Title &$title, IContextSource &$context, $including = false ) {
 503                 // @todo FIXME: Redirects broken due to this call
 504                 $bits = explode( '/', $title->getDBkey(), 2 );
 505                 $name = $bits[0];
 506                 if ( !isset( $bits[1] ) ) { // bug 2087
 507                         $par = null;
 508                 } else {
 509                         $par = $bits[1];
 510                 }
 511
 512                 $page = self::getPage( $name );
 513                 if ( !$page ) {
 514                         $context->getOutput()->setArticleRelated( false );
 515                         $context->getOutput()->setRobotPolicy( 'noindex,nofollow' );
 516
 517                         global $wgSend404Code;
 518                         if ( $wgSend404Code ) {
 519                                 $context->getOutput()->setStatusCode( 404 );
 520                         }
 521
 522                         $context->getOutput()->showErrorPage( 'nosuchspecialpage', 'nospecialpagetext' );
 523
 524                         return false;
 525                 }
 526
 527                 if ( !$including ) {
 528                         // Narrow DB query expectations for this HTTP request
 529                         $trxLimits = $context->getConfig()->get( 'TrxProfilerLimits' );
 530                         $trxProfiler = Profiler::instance()->getTransactionProfiler();
 531                         if ( $context->getRequest()->wasPosted() && !$page->doesWrites() ) {
 532                                 $trxProfiler->setExpectations( $trxLimits['POST-nonwrite'], __METHOD__ );
 533                         }
 534                 }
 535
 536                 // Page exists, set the context
 537                 $page->setContext( $context );
 538
 539                 if ( !$including ) {
 540                         // Redirect to canonical alias for GET commands
 541                         // Not for POST, we'd lose the post data, so it's best to just distribute
 542                         // the request. Such POST requests are possible for old extensions that
 543                         // generate self-links without being aware that their default name has
 544                         // changed.
 545                         if ( $name != $page->getLocalName() && !$context->getRequest()->wasPosted() ) {
 546                                 $query = $context->getRequest()->getQueryValues();
 547                                 unset( $query['title'] );
 548                                 $title = $page->getPageTitle( $par );
 549                                 $url = $title->getFullURL( $query );
 550                                 $context->getOutput()->redirect( $url );
 551
 552                                 return $title;
 553                         } else {
 554                                 $context->setTitle( $page->getPageTitle( $par ) );
 555                         }
 556                 } elseif ( !$page->isIncludable() ) {
 557                         return false;
 558                 }
 559
 560                 $page->including( $including );
 561
 562                 // Execute special page
 563                 $page->run( $par );
 564
 565                 return true;
 566         }
 567
 568         /**
 569          * Just like executePath() but will override global variables and execute
 570          * the page in "inclusion" mode. Returns true if the execution was
 571          * successful or false if there was no such special page, or a title object
 572          * if it was a redirect.
 573          *
 574          * Also saves the current $wgTitle, $wgOut, $wgRequest, $wgUser and $wgLang
 575          * variables so that the special page will get the context it'd expect on a
 576          * normal request, and then restores them to their previous values after.
 577          *
 578          * @param Title $title
 579          * @param IContextSource $context
 580          * @return string HTML fragment
 581          */
 582         public static function capturePath( Title $title, IContextSource $context ) {
 583                 global $wgOut, $wgTitle, $wgRequest, $wgUser, $wgLang;
 584
 585                 // Save current globals
 586                 $oldTitle = $wgTitle;
 587                 $oldOut = $wgOut;
 588                 $oldRequest = $wgRequest;
 589                 $oldUser = $wgUser;
 590                 $oldLang = $wgLang;
 591
 592                 // Set the globals to the current context
 593                 $wgTitle = $title;
 594                 $wgOut = $context->getOutput();
 595                 $wgRequest = $context->getRequest();
 596                 $wgUser = $context->getUser();
 597                 $wgLang = $context->getLanguage();
 598
 599                 // The useful part
 600                 $ret = self::executePath( $title, $context, true );
 601
 602                 // And restore the old globals
 603                 $wgTitle = $oldTitle;
 604                 $wgOut = $oldOut;
 605                 $wgRequest = $oldRequest;
 606                 $wgUser = $oldUser;
 607                 $wgLang = $oldLang;
 608
 609                 return $ret;
 610         }
 611
 612         /**
 613          * Get the local name for a specified canonical name
 614          *
 615          * @param string $name
 616          * @param string|bool $subpage
 617          * @return string
 618          */
 619         public static function getLocalNameFor( $name, $subpage = false ) {
 620                 global $wgContLang;
 621                 $aliases = $wgContLang->getSpecialPageAliases();
 622                 $aliasList = self::getAliasList();
 623
 624                 // Find the first alias that maps back to $name
 625                 if ( isset( $aliases[$name] ) ) {
 626                         $found = false;
 627                         foreach ( $aliases[$name] as $alias ) {
 628                                 $caseFoldedAlias = $wgContLang->caseFold( $alias );
 629                                 $caseFoldedAlias = str_replace( ' ', '_', $caseFoldedAlias );
 630                                 if ( isset( $aliasList[$caseFoldedAlias] ) &&
 631                                         $aliasList[$caseFoldedAlias] === $name
 632                                 ) {
 633                                         $name = $alias;
 634                                         $found = true;
 635                                         break;
 636                                 }
 637                         }
 638                         if ( !$found ) {
 639                                 wfWarn( "Did not find a usable alias for special page '$name'. " .
 640                                         "It seems all defined aliases conflict?" );
 641                         }
 642                 } else {
 643                         // Check if someone misspelled the correct casing
 644                         if ( is_array( $aliases ) ) {
 645                                 foreach ( $aliases as $n => $values ) {
 646                                         if ( strcasecmp( $name, $n ) === 0 ) {
 647                                                 wfWarn( "Found alias defined for $n when searching for " .
 648                                                         "special page aliases for $name. Case mismatch?" );
 649                                                 return self::getLocalNameFor( $n, $subpage );
 650                                         }
 651                                 }
 652                         }
 653
 654                         wfWarn( "Did not find alias for special page '$name'. " .
 655                                 "Perhaps no aliases are defined for it?" );
 656                 }
 657
 658                 if ( $subpage !== false && !is_null( $subpage ) ) {
 659                         $name = "$name/$subpage";
 660                 }
 661
 662                 return $wgContLang->ucfirst( $name );
 663         }
 664
 665         /**
 666          * Get a title for a given alias
 667          *
 668          * @param string $alias
 669          * @return Title|null Title or null if there is no such alias
 670          */
 671         public static function getTitleForAlias( $alias ) {
 672                 list( $name, $subpage ) = self::resolveAlias( $alias );
 673                 if ( $name != null ) {
 674                         return SpecialPage::getTitleFor( $name, $subpage );
 675                 } else {
 676                         return null;
 677                 }
 678         }
 679 }