includes/DoubleRedirectJob.php

   1 <?php
   2
   3 /**
   4  * Job to fix double redirects after moving a page
   5  *
   6  * @ingroup JobQueue
   7  */
   8 class DoubleRedirectJob extends Job {
   9         var $reason, $redirTitle, $destTitleText;
  10         static $user;
  11
  12         /**
  13          * Insert jobs into the job queue to fix redirects to the given title
  14          * @param $reason String: the reason for the fix, see message double-redirect-fixed-<reason>
  15          * @param $redirTitle Title: the title which has changed, redirects pointing to this title are fixed
  16          * @param $destTitle Not used
  17          */
  18         public static function fixRedirects( $reason, $redirTitle, $destTitle = false ) {
  19                 # Need to use the master to get the redirect table updated in the same transaction
  20                 $dbw = wfGetDB( DB_MASTER );
  21                 $res = $dbw->select(
  22                         array( 'redirect', 'page' ),
  23                         array( 'page_namespace', 'page_title' ),
  24                         array(
  25                                 'page_id = rd_from',
  26                                 'rd_namespace' => $redirTitle->getNamespace(),
  27                                 'rd_title' => $redirTitle->getDBkey()
  28                         ), __METHOD__ );
  29                 if ( !$res->numRows() ) {
  30                         return;
  31                 }
  32                 $jobs = array();
  33                 foreach ( $res as $row ) {
  34                         $title = Title::makeTitle( $row->page_namespace, $row->page_title );
  35                         if ( !$title ) {
  36                                 continue;
  37                         }
  38
  39                         $jobs[] = new self( $title, array(
  40                                 'reason' => $reason,
  41                                 'redirTitle' => $redirTitle->getPrefixedDBkey() ) );
  42                         # Avoid excessive memory usage
  43                         if ( count( $jobs ) > 10000 ) {
  44                                 Job::batchInsert( $jobs );
  45                                 $jobs = array();
  46                         }
  47                 }
  48                 Job::batchInsert( $jobs );
  49         }
  50         function __construct( $title, $params = false, $id = 0 ) {
  51                 parent::__construct( 'fixDoubleRedirect', $title, $params, $id );
  52                 $this->reason = $params['reason'];
  53                 $this->redirTitle = Title::newFromText( $params['redirTitle'] );
  54                 $this->destTitleText = !empty( $params['destTitle'] ) ? $params['destTitle'] : '';
  55         }
  56
  57         function run() {
  58                 if ( !$this->redirTitle ) {
  59                         $this->setLastError( 'Invalid title' );
  60                         return false;
  61                 }
  62
  63                 $targetRev = Revision::newFromTitle( $this->title );
  64                 if ( !$targetRev ) {
  65                         wfDebug( __METHOD__.": target redirect already deleted, ignoring\n" );
  66                         return true;
  67                 }
  68                 $text = $targetRev->getText();
  69                 $currentDest = Title::newFromRedirect( $text );
  70                 if ( !$currentDest || !$currentDest->equals( $this->redirTitle ) ) {
  71                         wfDebug( __METHOD__.": Redirect has changed since the job was queued\n" );
  72                         return true;
  73                 }
  74
  75                 # Check for a suppression tag (used e.g. in periodically archived discussions)
  76                 $mw = MagicWord::get( 'staticredirect' );
  77                 if ( $mw->match( $text ) ) {
  78                         wfDebug( __METHOD__.": skipping: suppressed with __STATICREDIRECT__\n" );
  79                         return true;
  80                 }
  81
  82                 # Find the current final destination
  83                 $newTitle = self::getFinalDestination( $this->redirTitle );
  84                 if ( !$newTitle ) {
  85                         wfDebug( __METHOD__.": skipping: single redirect, circular redirect or invalid redirect destination\n" );
  86                         return true;
  87                 }
  88                 if ( $newTitle->equals( $this->redirTitle ) ) {
  89                         # The redirect is already right, no need to change it
  90                         # This can happen if the page was moved back (say after vandalism)
  91                         wfDebug( __METHOD__.": skipping, already good\n" );
  92                 }
  93
  94                 # Preserve fragment (bug 14904)
  95                 $newTitle = Title::makeTitle( $newTitle->getNamespace(), $newTitle->getDBkey(),
  96                         $currentDest->getFragment() );
  97
  98                 # Fix the text
  99                 # Remember that redirect pages can have categories, templates, etc.,
 100                 # so the regex has to be fairly general
 101                 $newText = preg_replace( '/ \[ \[  [^\]]*  \] \] /x',
 102                         '[[' . $newTitle->getFullText() . ']]',
 103                         $text, 1 );
 104
 105                 if ( $newText === $text ) {
 106                         $this->setLastError( 'Text unchanged???' );
 107                         return false;
 108                 }
 109
 110                 # Save it
 111                 global $wgUser;
 112                 $oldUser = $wgUser;
 113                 $wgUser = $this->getUser();
 114                 $article = new Article( $this->title );
 115                 $reason = wfMsgForContent( 'double-redirect-fixed-' . $this->reason,
 116                         $this->redirTitle->getPrefixedText(), $newTitle->getPrefixedText() );
 117                 $article->doEdit( $newText, $reason, EDIT_UPDATE | EDIT_SUPPRESS_RC );
 118                 $wgUser = $oldUser;
 119
 120                 return true;
 121         }
 122
 123         /**
 124          * Get the final destination of a redirect
 125          * @return false if the specified title is not a redirect, or if it is a circular redirect
 126          */
 127         public static function getFinalDestination( $title ) {
 128                 $dbw = wfGetDB( DB_MASTER );
 129
 130                 $seenTitles = array(); # Circular redirect check
 131                 $dest = false;
 132
 133                 while ( true ) {
 134                         $titleText = $title->getPrefixedDBkey();
 135                         if ( isset( $seenTitles[$titleText] ) ) {
 136                                 wfDebug( __METHOD__, "Circular redirect detected, aborting\n" );
 137                                 return false;
 138                         }
 139                         $seenTitles[$titleText] = true;
 140
 141                         $row = $dbw->selectRow(
 142                                 array( 'redirect', 'page' ),
 143                                 array( 'rd_namespace', 'rd_title' ),
 144                                 array(
 145                                         'rd_from=page_id',
 146                                         'page_namespace' => $title->getNamespace(),
 147                                         'page_title' => $title->getDBkey()
 148                                 ), __METHOD__ );
 149                         if ( !$row ) {
 150                                 # No redirect from here, chain terminates
 151                                 break;
 152                         } else {
 153                                 $dest = $title = Title::makeTitle( $row->rd_namespace, $row->rd_title );
 154                         }
 155                 }
 156                 return $dest;
 157         }
 158
 159         /**
 160          * Get a user object for doing edits, from a request-lifetime cache
 161          */
 162         function getUser() {
 163                 if ( !self::$user ) {
 164                         self::$user = User::newFromName( wfMsgForContent( 'double-redirect-fixer' ), false );
 165                         if ( !self::$user->isLoggedIn() ) {
 166                                 self::$user->addToDatabase();
 167                         }
 168                 }
 169                 return self::$user;
 170         }
 171 }
 172