/**
  *  Applicable on image pages only, this changes the primary image on the page
  *  from the most recent to the approved revision.
  **/
 public static function onImagePageFindFile($imagePage, &$normalFile, &$displayFile)
 {
     // if ($normalFile)
     // $normalFile->purgeCache();
     // if ($displayFile)
     // $displayFile->purgeCache();
     list($approvedRev_ts, $approvedRev_sha1) = ApprovedRevs::GetApprovedFileInfo($imagePage->getFile()->getTitle());
     if (!$approvedRev_ts || !$approvedRev_sha1) {
         return true;
     }
     $title = $imagePage->getTitle();
     $displayFile = wfFindFile($title, array('time' => $approvedRev_ts));
     # If none found, try current
     if (!$displayFile) {
         wfDebug(__METHOD__ . ": {$title->getPrefixedDBkey()}: {$approvedRev_ts} not found, using current\n");
         $displayFile = wfFindFile($title);
         # If none found, use a valid local placeholder
         if (!$displayFile) {
             $displayFile = wfLocalFile($title);
             // fallback to current
         }
         $normalFile = $displayFile;
         # If found, set $normalFile
     } else {
         wfDebug(__METHOD__ . ": {$title->getPrefixedDBkey()}: using timestamp {$approvedRev_ts}\n");
         $normalFile = wfFindFile($title);
     }
     return true;
 }