includes/job/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 /**
  25  * Job to fix double redirects after moving a page
  26  *
  27  * @ingroup JobQueue
  28  */
  29 class DoubleRedirectJob extends Job {
  30         /** @var string Reason for the change, 'maintenance' or 'move'. Suffix fo
  31          *    message key 'double-redirect-fixed-'.
  32          */
  33         private $reason;
  34
  35         /** @var Title The title which has changed, redirects pointing to this
  36          *    title are fixed
  37          */
  38         private $redirTitle;
  39
  40         /** @var User */
  41         private static $user;
  42
  43         /**
  44          * Insert jobs into the job queue to fix redirects to the given title
  45          * @param string $reason the reason for the fix, see message
  46          *   "double-redirect-fixed-<reason>"
  47          * @param $redirTitle Title: the title which has changed, redirects
  48          *   pointing to this title are fixed
  49          * @param bool $destTitle Not used
  50          */
  51         public static function fixRedirects( $reason, $redirTitle, $destTitle = false ) {
  52                 # Need to use the master to get the redirect table updated in the same transaction
  53                 $dbw = wfGetDB( DB_MASTER );
  54                 $res = $dbw->select(
  55                         array( 'redirect', 'page' ),
  56                         array( 'page_namespace', 'page_title' ),
  57                         array(
  58                                 'page_id = rd_from',
  59                                 'rd_namespace' => $redirTitle->getNamespace(),
  60                                 'rd_title' => $redirTitle->getDBkey()
  61                         ), __METHOD__ );
  62                 if ( !$res->numRows() ) {
  63                         return;
  64                 }
  65                 $jobs = array();
  66                 foreach ( $res as $row ) {
  67                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
  68                         if ( !$title ) {
  69                                 continue;
  70                         }
  71
  72                         $jobs[] = new self( $title, array(
  73                                 'reason' => $reason,
  74                                 'redirTitle' => $redirTitle->getPrefixedDBkey() ) );
  75                         # Avoid excessive memory usage
  76                         if ( count( $jobs ) > 10000 ) {
  77                                 JobQueueGroup::singleton()->push( $jobs );
  78                                 $jobs = array();
  79                         }
  80                 }
  81                 JobQueueGroup::singleton()->push( $jobs );
  82         }
  83
  84         function __construct( $title, $params = false, $id = 0 ) {
  85                 parent::__construct( 'fixDoubleRedirect', $title, $params, $id );
  86                 $this->reason = $params['reason'];
  87                 $this->redirTitle = Title::newFromText( $params['redirTitle'] );
  88         }
  89
  90         /**
  91          * @return bool
  92          */
  93         function run() {
  94                 if ( !$this->redirTitle ) {
  95                         $this->setLastError( 'Invalid title' );
  96
  97                         return false;
  98                 }
  99
 100                 $targetRev = Revision::newFromTitle( $this->title, false, Revision::READ_LATEST );
 101                 if ( !$targetRev ) {
 102                         wfDebug( __METHOD__ . ": target redirect already deleted, ignoring\n" );
 103
 104                         return true;
 105                 }
 106                 $content = $targetRev->getContent();
 107                 $currentDest = $content ? $content->getRedirectTarget() : null;
 108                 if ( !$currentDest || !$currentDest->equals( $this->redirTitle ) ) {
 109                         wfDebug( __METHOD__ . ": Redirect has changed since the job was queued\n" );
 110
 111                         return true;
 112                 }
 113
 114                 // Check for a suppression tag (used e.g. in periodically archived discussions)
 115                 $mw = MagicWord::get( 'staticredirect' );
 116                 if ( $content->matchMagicWord( $mw ) ) {
 117                         wfDebug( __METHOD__ . ": skipping: suppressed with __STATICREDIRECT__\n" );
 118
 119                         return true;
 120                 }
 121
 122                 // Find the current final destination
 123                 $newTitle = self::getFinalDestination( $this->redirTitle );
 124                 if ( !$newTitle ) {
 125                         wfDebug( __METHOD__ .
 126                                 ": skipping: single redirect, circular redirect or invalid redirect destination\n" );
 127
 128                         return true;
 129                 }
 130                 if ( $newTitle->equals( $this->redirTitle ) ) {
 131                         // The redirect is already right, no need to change it
 132                         // This can happen if the page was moved back (say after vandalism)
 133                         wfDebug( __METHOD__ . " : skipping, already good\n" );
 134                 }
 135
 136                 // Preserve fragment (bug 14904)
 137                 $newTitle = Title::makeTitle( $newTitle->getNamespace(), $newTitle->getDBkey(),
 138                         $currentDest->getFragment(), $newTitle->getInterwiki() );
 139
 140                 // Fix the text
 141                 $newContent = $content->updateRedirect( $newTitle );
 142
 143                 if ( $newContent->equals( $content ) ) {
 144                         $this->setLastError( 'Content unchanged???' );
 145
 146                         return false;
 147                 }
 148
 149                 $user = $this->getUser();
 150                 if ( !$user ) {
 151                         $this->setLastError( 'Invalid user' );
 152
 153                         return false;
 154                 }
 155
 156                 // Save it
 157                 global $wgUser;
 158                 $oldUser = $wgUser;
 159                 $wgUser = $user;
 160                 $article = WikiPage::factory( $this->title );
 161
 162                 // Messages: double-redirect-fixed-move, double-redirect-fixed-maintenance
 163                 $reason = wfMessage( 'double-redirect-fixed-' . $this->reason,
 164                         $this->redirTitle->getPrefixedText(), $newTitle->getPrefixedText()
 165                 )->inContentLanguage()->text();
 166                 $article->doEditContent( $newContent, $reason, EDIT_UPDATE | EDIT_SUPPRESS_RC, false, $user );
 167                 $wgUser = $oldUser;
 168
 169                 return true;
 170         }
 171
 172         /**
 173          * Get the final destination of a redirect
 174          *
 175          * @param $title Title
 176          *
 177          * @return bool if the specified title is not a redirect, or if it is a circular redirect
 178          */
 179         public static function getFinalDestination( $title ) {
 180                 $dbw = wfGetDB( DB_MASTER );
 181
 182                 // Circular redirect check
 183                 $seenTitles = array();
 184                 $dest = false;
 185
 186                 while ( true ) {
 187                         $titleText = $title->getPrefixedDBkey();
 188                         if ( isset( $seenTitles[$titleText] ) ) {
 189                                 wfDebug( __METHOD__, "Circular redirect detected, aborting\n" );
 190
 191                                 return false;
 192                         }
 193                         $seenTitles[$titleText] = true;
 194
 195                         if ( $title->getInterwiki() ) {
 196                                 // If the target is interwiki, we have to break early (bug 40352).
 197                                 // Otherwise it will look up a row in the local page table
 198                                 // with the namespace/page of the interwiki target which can cause
 199                                 // unexpected results (e.g. X -> foo:Bar -> Bar -> .. )
 200                                 break;
 201                         }
 202
 203                         $row = $dbw->selectRow(
 204                                 array( 'redirect', 'page' ),
 205                                 array( 'rd_namespace', 'rd_title', 'rd_interwiki' ),
 206                                 array(
 207                                         'rd_from=page_id',
 208                                         'page_namespace' => $title->getNamespace(),
 209                                         'page_title' => $title->getDBkey()
 210                                 ), __METHOD__ );
 211                         if ( !$row ) {
 212                                 # No redirect from here, chain terminates
 213                                 break;
 214                         } else {
 215                                 $dest = $title = Title::makeTitle(
 216                                         $row->rd_namespace,
 217                                         $row->rd_title,
 218                                         '',
 219                                         $row->rd_interwiki
 220                                 );
 221                         }
 222                 }
 223
 224                 return $dest;
 225         }
 226
 227         /**
 228          * Get a user object for doing edits, from a request-lifetime cache
 229          * False will be returned if the user name specified in the
 230          * 'double-redirect-fixer' message is invalid.
 231          *
 232          * @return User|bool
 233          */
 234         function getUser() {
 235                 if ( !self::$user ) {
 236                         $username = wfMessage( 'double-redirect-fixer' )->inContentLanguage()->text();
 237                         self::$user = User::newFromName( $username );
 238                         # User::newFromName() can return false on a badly configured wiki.
 239                         if ( self::$user && !self::$user->isLoggedIn() ) {
 240                                 self::$user->addToDatabase();
 241                         }
 242                 }
 243
 244                 return self::$user;
 245         }
 246 }