includes/jobqueue/jobs/DoubleRedirectJob.php

   1 <?php
   2 /**
   3  * Job to fix double redirects after moving a page.
   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 JobQueue
  22  */
  23
  24 use MediaWiki\MediaWikiServices;
  25
  26 /**
  27  * Job to fix double redirects after moving a page
  28  *
  29  * @ingroup JobQueue
  30  */
  31 class DoubleRedirectJob extends Job {
  32
  33         /** @var Title The title which has changed, redirects pointing to this
  34          *    title are fixed
  35          */
  36         private $redirTitle;
  37
  38         /** @var User */
  39         private static $user;
  40
  41         /**
  42          * @param Title $title
  43          * @param array $params Expected to contain these elements:
  44          * - 'redirTitle' => string The title that changed and should be fixed.
  45          * - 'reason' => string Reason for the change, can be "move" or "maintenance". Used as a suffix
  46          *   for the message keys "double-redirect-fixed-move" and
  47          *   "double-redirect-fixed-maintenance".
  48          * ]
  49          */
  50         function __construct( Title $title, array $params ) {
  51                 parent::__construct( 'fixDoubleRedirect', $title, $params );
  52                 $this->redirTitle = Title::newFromText( $params['redirTitle'] );
  53         }
  54
  55         /**
  56          * Insert jobs into the job queue to fix redirects to the given title
  57          * @param string $reason The reason for the fix, see message
  58          *   "double-redirect-fixed-<reason>"
  59          * @param Title $redirTitle The title which has changed, redirects
  60          *   pointing to this title are fixed
  61          * @param bool $destTitle Not used
  62          */
  63         public static function fixRedirects( $reason, $redirTitle, $destTitle = false ) {
  64                 # Need to use the master to get the redirect table updated in the same transaction
  65                 $dbw = wfGetDB( DB_MASTER );
  66                 $res = $dbw->select(
  67                         [ 'redirect', 'page' ],
  68                         [ 'page_namespace', 'page_title' ],
  69                         [
  70                                 'page_id = rd_from',
  71                                 'rd_namespace' => $redirTitle->getNamespace(),
  72                                 'rd_title' => $redirTitle->getDBkey()
  73                         ], __METHOD__ );
  74                 if ( !$res->numRows() ) {
  75                         return;
  76                 }
  77                 $jobs = [];
  78                 foreach ( $res as $row ) {
  79                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
  80                         if ( !$title ) {
  81                                 continue;
  82                         }
  83
  84                         $jobs[] = new self( $title, [
  85                                 'reason' => $reason,
  86                                 'redirTitle' => $redirTitle->getPrefixedDBkey() ] );
  87                         # Avoid excessive memory usage
  88                         if ( count( $jobs ) > 10000 ) {
  89                                 JobQueueGroup::singleton()->push( $jobs );
  90                                 $jobs = [];
  91                         }
  92                 }
  93                 JobQueueGroup::singleton()->push( $jobs );
  94         }
  95
  96         /**
  97          * @return bool
  98          */
  99         function run() {
 100                 if ( !$this->redirTitle ) {
 101                         $this->setLastError( 'Invalid title' );
 102
 103                         return false;
 104                 }
 105
 106                 $targetRev = Revision::newFromTitle( $this->title, false, Revision::READ_LATEST );
 107                 if ( !$targetRev ) {
 108                         wfDebug( __METHOD__ . ": target redirect already deleted, ignoring\n" );
 109
 110                         return true;
 111                 }
 112                 $content = $targetRev->getContent();
 113                 $currentDest = $content ? $content->getRedirectTarget() : null;
 114                 if ( !$currentDest || !$currentDest->equals( $this->redirTitle ) ) {
 115                         wfDebug( __METHOD__ . ": Redirect has changed since the job was queued\n" );
 116
 117                         return true;
 118                 }
 119
 120                 // Check for a suppression tag (used e.g. in periodically archived discussions)
 121                 $mw = MediaWikiServices::getInstance()->getMagicWordFactory()->get( 'staticredirect' );
 122                 if ( $content->matchMagicWord( $mw ) ) {
 123                         wfDebug( __METHOD__ . ": skipping: suppressed with __STATICREDIRECT__\n" );
 124
 125                         return true;
 126                 }
 127
 128                 // Find the current final destination
 129                 $newTitle = self::getFinalDestination( $this->redirTitle );
 130                 if ( !$newTitle ) {
 131                         wfDebug( __METHOD__ .
 132                                 ": skipping: single redirect, circular redirect or invalid redirect destination\n" );
 133
 134                         return true;
 135                 }
 136                 if ( $newTitle->equals( $this->redirTitle ) ) {
 137                         // The redirect is already right, no need to change it
 138                         // This can happen if the page was moved back (say after vandalism)
 139                         wfDebug( __METHOD__ . " : skipping, already good\n" );
 140                 }
 141
 142                 // Preserve fragment (T16904)
 143                 $newTitle = Title::makeTitle( $newTitle->getNamespace(), $newTitle->getDBkey(),
 144                         $currentDest->getFragment(), $newTitle->getInterwiki() );
 145
 146                 // Fix the text
 147                 $newContent = $content->updateRedirect( $newTitle );
 148
 149                 if ( $newContent->equals( $content ) ) {
 150                         $this->setLastError( 'Content unchanged???' );
 151
 152                         return false;
 153                 }
 154
 155                 $user = $this->getUser();
 156                 if ( !$user ) {
 157                         $this->setLastError( 'Invalid user' );
 158
 159                         return false;
 160                 }
 161
 162                 // Save it
 163                 global $wgUser;
 164                 $oldUser = $wgUser;
 165                 $wgUser = $user;
 166                 $article = WikiPage::factory( $this->title );
 167
 168                 // Messages: double-redirect-fixed-move, double-redirect-fixed-maintenance
 169                 $reason = wfMessage( 'double-redirect-fixed-' . $this->params['reason'],
 170                         $this->redirTitle->getPrefixedText(), $newTitle->getPrefixedText()
 171                 )->inContentLanguage()->text();
 172                 $flags = EDIT_UPDATE | EDIT_SUPPRESS_RC | EDIT_INTERNAL;
 173                 $article->doEditContent( $newContent, $reason, $flags, false, $user );
 174                 $wgUser = $oldUser;
 175
 176                 return true;
 177         }
 178
 179         /**
 180          * Get the final destination of a redirect
 181          *
 182          * @param Title $title
 183          *
 184          * @return Title|bool The final Title after following all redirects, or false if
 185          *  the page is not a redirect or the redirect loops.
 186          */
 187         public static function getFinalDestination( $title ) {
 188                 $dbw = wfGetDB( DB_MASTER );
 189
 190                 // Circular redirect check
 191                 $seenTitles = [];
 192                 $dest = false;
 193
 194                 while ( true ) {
 195                         $titleText = $title->getPrefixedDBkey();
 196                         if ( isset( $seenTitles[$titleText] ) ) {
 197                                 wfDebug( __METHOD__, "Circular redirect detected, aborting\n" );
 198
 199                                 return false;
 200                         }
 201                         $seenTitles[$titleText] = true;
 202
 203                         if ( $title->isExternal() ) {
 204                                 // If the target is interwiki, we have to break early (T42352).
 205                                 // Otherwise it will look up a row in the local page table
 206                                 // with the namespace/page of the interwiki target which can cause
 207                                 // unexpected results (e.g. X -> foo:Bar -> Bar -> .. )
 208                                 break;
 209                         }
 210
 211                         $row = $dbw->selectRow(
 212                                 [ 'redirect', 'page' ],
 213                                 [ 'rd_namespace', 'rd_title', 'rd_interwiki' ],
 214                                 [
 215                                         'rd_from=page_id',
 216                                         'page_namespace' => $title->getNamespace(),
 217                                         'page_title' => $title->getDBkey()
 218                                 ], __METHOD__ );
 219                         if ( !$row ) {
 220                                 # No redirect from here, chain terminates
 221                                 break;
 222                         } else {
 223                                 $dest = $title = Title::makeTitle(
 224                                         $row->rd_namespace,
 225                                         $row->rd_title,
 226                                         '',
 227                                         $row->rd_interwiki
 228                                 );
 229                         }
 230                 }
 231
 232                 return $dest;
 233         }
 234
 235         /**
 236          * Get a user object for doing edits, from a request-lifetime cache
 237          * False will be returned if the user name specified in the
 238          * 'double-redirect-fixer' message is invalid.
 239          *
 240          * @return User|bool
 241          */
 242         function getUser() {
 243                 if ( !self::$user ) {
 244                         $username = wfMessage( 'double-redirect-fixer' )->inContentLanguage()->text();
 245                         self::$user = User::newFromName( $username );
 246                         # User::newFromName() can return false on a badly configured wiki.
 247                         if ( self::$user && !self::$user->isLoggedIn() ) {
 248                                 self::$user->addToDatabase();
 249                         }
 250                 }
 251
 252                 return self::$user;
 253         }
 254 }