thumb.php

   1 <?php
   2 /**
   3  * PHP script to stream out an image thumbnail.
   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 Media
  22  */
  23
  24 define( 'MW_NO_OUTPUT_COMPRESSION', 1 );
  25 require __DIR__ . '/includes/WebStart.php';
  26
  27 // Don't use fancy MIME detection, just check the file extension for jpg/gif/png
  28 $wgTrivialMimeDetection = true;
  29
  30 if ( defined( 'THUMB_HANDLER' ) ) {
  31         // Called from thumb_handler.php via 404; extract params from the URI...
  32         wfThumbHandle404();
  33 } else {
  34         // Called directly, use $_GET params
  35         wfStreamThumb( $_GET );
  36 }
  37
  38 $mediawiki = new MediaWiki();
  39 $mediawiki->doPostOutputShutdown( 'fast' );
  40
  41 //--------------------------------------------------------------------------
  42
  43 /**
  44  * Handle a thumbnail request via thumbnail file URL
  45  *
  46  * @return void
  47  */
  48 function wfThumbHandle404() {
  49         global $wgArticlePath;
  50
  51         # Set action base paths so that WebRequest::getPathInfo()
  52         # recognizes the "X" as the 'title' in ../thumb_handler.php/X urls.
  53         # Note: If Custom per-extension repo paths are set, this may break.
  54         $repo = RepoGroup::singleton()->getLocalRepo();
  55         $oldArticlePath = $wgArticlePath;
  56         $wgArticlePath = $repo->getZoneUrl( 'thumb' ) . '/$1';
  57
  58         $matches = WebRequest::getPathInfo();
  59
  60         $wgArticlePath = $oldArticlePath;
  61
  62         if ( !isset( $matches['title'] ) ) {
  63                 wfThumbError( 404, 'Could not determine the name of the requested thumbnail.' );
  64                 return;
  65         }
  66
  67         $params = wfExtractThumbRequestInfo( $matches['title'] ); // basic wiki URL param extracting
  68         if ( $params == null ) {
  69                 wfThumbError( 400, 'The specified thumbnail parameters are not recognized.' );
  70                 return;
  71         }
  72
  73         wfStreamThumb( $params ); // stream the thumbnail
  74 }
  75
  76 /**
  77  * Stream a thumbnail specified by parameters
  78  *
  79  * @param array $params List of thumbnailing parameters. In addition to parameters
  80  *  passed to the MediaHandler, this may also includes the keys:
  81  *   f (for filename), archived (if archived file), temp (if temp file),
  82  *   w (alias for width), p (alias for page), r (ignored; historical),
  83  *   rel404 (path for render on 404 to verify hash path correct),
  84  *   thumbName (thumbnail name to potentially extract more parameters from
  85  *   e.g. 'lossy-page1-120px-Foo.tiff' would add page, lossy and width
  86  *   to the parameters)
  87  * @return void
  88  */
  89 function wfStreamThumb( array $params ) {
  90         global $wgVaryOnXFP;
  91
  92
  93         $headers = array(); // HTTP headers to send
  94
  95         $fileName = isset( $params['f'] ) ? $params['f'] : '';
  96
  97         // Backwards compatibility parameters
  98         if ( isset( $params['w'] ) ) {
  99                 $params['width'] = $params['w'];
 100                 unset( $params['w'] );
 101         }
 102         if ( isset( $params['width'] ) && substr( $params['width'], -2 ) == 'px' ) {
 103                 // strip the px (pixel) suffix, if found
 104                 $params['width'] = substr( $params['width'], 0, -2 );
 105         }
 106         if ( isset( $params['p'] ) ) {
 107                 $params['page'] = $params['p'];
 108         }
 109
 110         // Is this a thumb of an archived file?
 111         $isOld = ( isset( $params['archived'] ) && $params['archived'] );
 112         unset( $params['archived'] ); // handlers don't care
 113
 114         // Is this a thumb of a temp file?
 115         $isTemp = ( isset( $params['temp'] ) && $params['temp'] );
 116         unset( $params['temp'] ); // handlers don't care
 117
 118         // Some basic input validation
 119         $fileName = strtr( $fileName, '\\/', '__' );
 120
 121         // Actually fetch the image. Method depends on whether it is archived or not.
 122         if ( $isTemp ) {
 123                 $repo = RepoGroup::singleton()->getLocalRepo()->getTempRepo();
 124                 $img = new UnregisteredLocalFile( null, $repo,
 125                         # Temp files are hashed based on the name without the timestamp.
 126                         # The thumbnails will be hashed based on the entire name however.
 127                         # @todo fix this convention to actually be reasonable.
 128                         $repo->getZonePath( 'public' ) . '/' . $repo->getTempHashPath( $fileName ) . $fileName
 129                 );
 130         } elseif ( $isOld ) {
 131                 // Format is <timestamp>!<name>
 132                 $bits = explode( '!', $fileName, 2 );
 133                 if ( count( $bits ) != 2 ) {
 134                         wfThumbError( 404, wfMessage( 'badtitletext' )->parse() );
 135                         return;
 136                 }
 137                 $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
 138                 if ( !$title ) {
 139                         wfThumbError( 404, wfMessage( 'badtitletext' )->parse() );
 140                         return;
 141                 }
 142                 $img = RepoGroup::singleton()->getLocalRepo()->newFromArchiveName( $title, $fileName );
 143         } else {
 144                 $img = wfLocalFile( $fileName );
 145         }
 146
 147         // Check the source file title
 148         if ( !$img ) {
 149                 wfThumbError( 404, wfMessage( 'badtitletext' )->parse() );
 150                 return;
 151         }
 152
 153         // Check permissions if there are read restrictions
 154         $varyHeader = array();
 155         if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 156                 if ( !$img->getTitle() || !$img->getTitle()->userCan( 'read' ) ) {
 157                         wfThumbError( 403, 'Access denied. You do not have permission to access ' .
 158                                 'the source file.' );
 159                         return;
 160                 }
 161                 $headers[] = 'Cache-Control: private';
 162                 $varyHeader[] = 'Cookie';
 163         }
 164
 165         // Check if the file is hidden
 166         if ( $img->isDeleted( File::DELETED_FILE ) ) {
 167                 wfThumbError( 404, "The source file '$fileName' does not exist." );
 168                 return;
 169         }
 170
 171         // Do rendering parameters extraction from thumbnail name.
 172         if ( isset( $params['thumbName'] ) ) {
 173                 $params = wfExtractThumbParams( $img, $params );
 174         }
 175         if ( $params == null ) {
 176                 wfThumbError( 400, 'The specified thumbnail parameters are not recognized.' );
 177                 return;
 178         }
 179
 180         // Check the source file storage path
 181         if ( !$img->exists() ) {
 182                 $redirectedLocation = false;
 183                 if ( !$isTemp ) {
 184                         // Check for file redirect
 185                         // Since redirects are associated with pages, not versions of files,
 186                         // we look for the most current version to see if its a redirect.
 187                         $possRedirFile = RepoGroup::singleton()->getLocalRepo()->findFile( $img->getName() );
 188                         if ( $possRedirFile && !is_null( $possRedirFile->getRedirected() ) ) {
 189                                 $redirTarget = $possRedirFile->getName();
 190                                 $targetFile = wfLocalFile( Title::makeTitleSafe( NS_FILE, $redirTarget ) );
 191                                 if ( $targetFile->exists() ) {
 192                                         $newThumbName = $targetFile->thumbName( $params );
 193                                         if ( $isOld ) {
 194                                                 $newThumbUrl = $targetFile->getArchiveThumbUrl(
 195                                                         $bits[0] . '!' . $targetFile->getName(), $newThumbName );
 196                                         } else {
 197                                                 $newThumbUrl = $targetFile->getThumbUrl( $newThumbName );
 198                                         }
 199                                         $redirectedLocation = wfExpandUrl( $newThumbUrl, PROTO_CURRENT );
 200                                 }
 201                         }
 202                 }
 203
 204                 if ( $redirectedLocation ) {
 205                         // File has been moved. Give redirect.
 206                         $response = RequestContext::getMain()->getRequest()->response();
 207                         $response->statusHeader( 302 );
 208                         $response->header( 'Location: ' . $redirectedLocation );
 209                         $response->header( 'Expires: ' .
 210                                 gmdate( 'D, d M Y H:i:s', time() + 12 * 3600 ) . ' GMT' );
 211                         if ( $wgVaryOnXFP ) {
 212                                 $varyHeader[] = 'X-Forwarded-Proto';
 213                         }
 214                         if ( count( $varyHeader ) ) {
 215                                 $response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
 216                         }
 217                         return;
 218                 }
 219
 220                 // If its not a redirect that has a target as a local file, give 404.
 221                 wfThumbError( 404, "The source file '$fileName' does not exist." );
 222                 return;
 223         } elseif ( $img->getPath() === false ) {
 224                 wfThumbError( 500, "The source file '$fileName' is not locally accessible." );
 225                 return;
 226         }
 227
 228         // Check IMS against the source file
 229         // This means that clients can keep a cached copy even after it has been deleted on the server
 230         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 231                 // Fix IE brokenness
 232                 $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 233                 // Calculate time
 234                 wfSuppressWarnings();
 235                 $imsUnix = strtotime( $imsString );
 236                 wfRestoreWarnings();
 237                 if ( wfTimestamp( TS_UNIX, $img->getTimestamp() ) <= $imsUnix ) {
 238                         HttpStatus::header( 304  );
 239                         return;
 240                 }
 241         }
 242
 243         $rel404 = isset( $params['rel404'] ) ? $params['rel404'] : null;
 244         unset( $params['r'] ); // ignore 'r' because we unconditionally pass File::RENDER
 245         unset( $params['f'] ); // We're done with 'f' parameter.
 246         unset( $params['rel404'] ); // moved to $rel404
 247
 248         // Get the normalized thumbnail name from the parameters...
 249         try {
 250                 $thumbName = $img->thumbName( $params );
 251                 if ( !strlen( $thumbName ) ) { // invalid params?
 252                         throw new MediaTransformInvalidParametersException( 'Empty return from File::thumbName' );
 253                 }
 254                 $thumbName2 = $img->thumbName( $params, File::THUMB_FULL_NAME ); // b/c; "long" style
 255         } catch ( MediaTransformInvalidParametersException $e ) {
 256                 wfThumbError( 400, 'The specified thumbnail parameters are not valid: ' . $e->getMessage() );
 257                 return;
 258         } catch ( MWException $e ) {
 259                 wfThumbError( 500, $e->getHTML() );
 260                 return;
 261         }
 262
 263         // For 404 handled thumbnails, we only use the base name of the URI
 264         // for the thumb params and the parent directory for the source file name.
 265         // Check that the zone relative path matches up so squid caches won't pick
 266         // up thumbs that would not be purged on source file deletion (bug 34231).
 267         if ( $rel404 !== null ) { // thumbnail was handled via 404
 268                 if ( rawurldecode( $rel404 ) === $img->getThumbRel( $thumbName ) ) {
 269                         // Request for the canonical thumbnail name
 270                 } elseif ( rawurldecode( $rel404 ) === $img->getThumbRel( $thumbName2 ) ) {
 271                         // Request for the "long" thumbnail name; redirect to canonical name
 272                         $response = RequestContext::getMain()->getRequest()->response();
 273                         $response->statusHeader( 301 );
 274                         $response->header( 'Location: ' .
 275                                 wfExpandUrl( $img->getThumbUrl( $thumbName ), PROTO_CURRENT ) );
 276                         $response->header( 'Expires: ' .
 277                                 gmdate( 'D, d M Y H:i:s', time() + 7 * 86400 ) . ' GMT' );
 278                         if ( $wgVaryOnXFP ) {
 279                                 $varyHeader[] = 'X-Forwarded-Proto';
 280                         }
 281                         if ( count( $varyHeader ) ) {
 282                                 $response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
 283                         }
 284                         return;
 285                 } else {
 286                         wfThumbError( 404, "The given path of the specified thumbnail is incorrect;
 287                                 expected '" . $img->getThumbRel( $thumbName ) . "' but got '" .
 288                                 rawurldecode( $rel404 ) . "'." );
 289                         return;
 290                 }
 291         }
 292
 293         $dispositionType = isset( $params['download'] ) ? 'attachment' : 'inline';
 294
 295         // Suggest a good name for users downloading this thumbnail
 296         $headers[] = "Content-Disposition: {$img->getThumbDisposition( $thumbName, $dispositionType )}";
 297
 298         if ( count( $varyHeader ) ) {
 299                 $headers[] = 'Vary: ' . implode( ', ', $varyHeader );
 300         }
 301
 302         // Stream the file if it exists already...
 303         $thumbPath = $img->getThumbPath( $thumbName );
 304         if ( $img->getRepo()->fileExists( $thumbPath ) ) {
 305                 $success = $img->getRepo()->streamFile( $thumbPath, $headers );
 306                 if ( !$success ) {
 307                         wfThumbError( 500, 'Could not stream the file' );
 308                 }
 309                 return;
 310         }
 311
 312         $user = RequestContext::getMain()->getUser();
 313         if ( !wfThumbIsStandard( $img, $params ) && $user->pingLimiter( 'renderfile-nonstandard' ) ) {
 314                 wfThumbError( 500, wfMessage( 'actionthrottledtext' )->parse() );
 315                 return;
 316         } elseif ( $user->pingLimiter( 'renderfile' ) ) {
 317                 wfThumbError( 500, wfMessage( 'actionthrottledtext' )->parse() );
 318                 return;
 319         }
 320
 321         // Actually generate a new thumbnail
 322         list( $thumb, $errorMsg ) = wfGenerateThumbnail( $img, $params, $thumbName, $thumbPath );
 323         /** @var MediaTransformOutput|bool $thumb */
 324
 325         // Check for thumbnail generation errors...
 326         $msg = wfMessage( 'thumbnail_error' );
 327         $errorCode = 500;
 328         if ( !$thumb ) {
 329                 $errorMsg = $errorMsg ?: $msg->rawParams( 'File::transform() returned false' )->escaped();
 330         } elseif ( $thumb->isError() ) {
 331                 $errorMsg = $thumb->getHtmlMsg();
 332         } elseif ( !$thumb->hasFile() ) {
 333                 $errorMsg = $msg->rawParams( 'No path supplied in thumbnail object' )->escaped();
 334         } elseif ( $thumb->fileIsSource() ) {
 335                 $errorMsg = $msg->
 336                         rawParams( 'Image was not scaled, is the requested width bigger than the source?' )->escaped();
 337                 $errorCode = 400;
 338         }
 339
 340         if ( $errorMsg !== false ) {
 341                 wfThumbError( $errorCode, $errorMsg );
 342         } else {
 343                 // Stream the file if there were no errors
 344                 $success = $thumb->streamFile( $headers );
 345                 if ( !$success ) {
 346                         wfThumbError( 500, 'Could not stream the file' );
 347                 }
 348         }
 349 }
 350
 351 /**
 352  * Actually try to generate a new thumbnail
 353  *
 354  * @param File $file
 355  * @param array $params
 356  * @param string $thumbName
 357  * @param string $thumbPath
 358  * @return array (MediaTransformOutput|bool, string|bool error message HTML)
 359  */
 360 function wfGenerateThumbnail( File $file, array $params, $thumbName, $thumbPath ) {
 361         global $wgMemc, $wgAttemptFailureEpoch;
 362
 363         $key = wfMemcKey( 'attempt-failures', $wgAttemptFailureEpoch,
 364                 $file->getRepo()->getName(), $file->getSha1(), md5( $thumbName ) );
 365
 366         // Check if this file keeps failing to render
 367         if ( $wgMemc->get( $key ) >= 4 ) {
 368                 return array( false, wfMessage( 'thumbnail_image-failure-limit', 4 ) );
 369         }
 370
 371         $done = false;
 372         // Record failures on PHP fatals in addition to caching exceptions
 373         register_shutdown_function( function () use ( &$done, $key ) {
 374                 if ( !$done ) { // transform() gave a fatal
 375                         global $wgMemc;
 376                         // Randomize TTL to reduce stampedes
 377                         $wgMemc->incrWithInit( $key, 3600 + mt_rand( 0, 300 ) );
 378                 }
 379         } );
 380
 381         $thumb = false;
 382         $errorHtml = false;
 383
 384         // guard thumbnail rendering with PoolCounter to avoid stampedes
 385         // expensive files use a separate PoolCounter config so it is possible
 386         // to set up a global limit on them
 387         if ( $file->isExpensiveToThumbnail() ) {
 388                 $poolCounterType = 'FileRenderExpensive';
 389         } else {
 390                 $poolCounterType = 'FileRender';
 391         }
 392
 393         // Thumbnail isn't already there, so create the new thumbnail...
 394         try {
 395                 $work = new PoolCounterWorkViaCallback( $poolCounterType, sha1( $file->getName() ),
 396                         array(
 397                                 'doWork' => function () use ( $file, $params ) {
 398                                         return $file->transform( $params, File::RENDER_NOW );
 399                                 },
 400                                 'getCachedWork' => function () use ( $file, $params, $thumbPath ) {
 401                                         // If the worker that finished made this thumbnail then use it.
 402                                         // Otherwise, it probably made a different thumbnail for this file.
 403                                         return $file->getRepo()->fileExists( $thumbPath )
 404                                                 ? $file->transform( $params, File::RENDER_NOW )
 405                                                 : false; // retry once more in exclusive mode
 406                                 },
 407                                 'fallback' => function () {
 408                                         return wfMessage( 'generic-pool-error' )->parse();
 409                                 },
 410                                 'error' => function ( $status ) {
 411                                         return $status->getHTML();
 412                                 }
 413                         )
 414                 );
 415                 $result = $work->execute();
 416                 if ( $result instanceof MediaTransformOutput ) {
 417                         $thumb = $result;
 418                 } elseif ( is_string( $result ) ) { // error
 419                         $errorHtml = $result;
 420                 }
 421         } catch ( Exception $e ) {
 422                 // Tried to select a page on a non-paged file?
 423         }
 424
 425         $done = true; // no PHP fatal occured
 426
 427         if ( !$thumb || $thumb->isError() ) {
 428                 // Randomize TTL to reduce stampedes
 429                 $wgMemc->incrWithInit( $key, 3600 + mt_rand( 0, 300 ) );
 430         }
 431
 432         return array( $thumb, $errorHtml );
 433 }
 434
 435 /**
 436  * Convert pathinfo type parameter, into normal request parameters
 437  *
 438  * So for example, if the request was redirected from
 439  * /w/images/thumb/a/ab/Foo.png/120px-Foo.png. The $thumbRel parameter
 440  * of this function would be set to "a/ab/Foo.png/120px-Foo.png".
 441  * This method is responsible for turning that into an array
 442  * with the folowing keys:
 443  *  * f => the filename (Foo.png)
 444  *  * rel404 => the whole thing (a/ab/Foo.png/120px-Foo.png)
 445  *  * archived => 1 (If the request is for an archived thumb)
 446  *  * temp => 1 (If the file is in the "temporary" zone)
 447  *  * thumbName => the thumbnail name, including parameters (120px-Foo.png)
 448  *
 449  * Transform specific parameters are set later via wfExtractThumbParams().
 450  *
 451  * @param string $thumbRel Thumbnail path relative to the thumb zone
 452  * @return array|null Associative params array or null
 453  */
 454 function wfExtractThumbRequestInfo( $thumbRel ) {
 455         $repo = RepoGroup::singleton()->getLocalRepo();
 456
 457         $hashDirReg = $subdirReg = '';
 458         $hashLevels = $repo->getHashLevels();
 459         for ( $i = 0; $i < $hashLevels; $i++ ) {
 460                 $subdirReg .= '[0-9a-f]';
 461                 $hashDirReg .= "$subdirReg/";
 462         }
 463
 464         // Check if this is a thumbnail of an original in the local file repo
 465         if ( preg_match( "!^((archive/)?$hashDirReg([^/]*)/([^/]*))$!", $thumbRel, $m ) ) {
 466                 list( /*all*/, $rel, $archOrTemp, $filename, $thumbname ) = $m;
 467         // Check if this is a thumbnail of an temp file in the local file repo
 468         } elseif ( preg_match( "!^(temp/)($hashDirReg([^/]*)/([^/]*))$!", $thumbRel, $m ) ) {
 469                 list( /*all*/, $archOrTemp, $rel, $filename, $thumbname ) = $m;
 470         } else {
 471                 return null; // not a valid looking thumbnail request
 472         }
 473
 474         $params = array( 'f' => $filename, 'rel404' => $rel );
 475         if ( $archOrTemp === 'archive/' ) {
 476                 $params['archived'] = 1;
 477         } elseif ( $archOrTemp === 'temp/' ) {
 478                 $params['temp'] = 1;
 479         }
 480
 481         $params['thumbName'] = $thumbname;
 482         return $params;
 483 }
 484
 485 /**
 486  * Convert a thumbnail name (122px-foo.png) to parameters, using
 487  * file handler.
 488  *
 489  * @param File $file File object for file in question
 490  * @param array $params Array of parameters so far
 491  * @return array Parameters array with more parameters
 492  */
 493 function wfExtractThumbParams( $file, $params ) {
 494         if ( !isset( $params['thumbName'] ) ) {
 495                 throw new MWException( "No thumbnail name passed to wfExtractThumbParams" );
 496         }
 497
 498         $thumbname = $params['thumbName'];
 499         unset( $params['thumbName'] );
 500
 501         // Do the hook first for older extensions that rely on it.
 502         if ( !Hooks::run( 'ExtractThumbParameters', array( $thumbname, &$params ) ) ) {
 503                 // Check hooks if parameters can be extracted
 504                 // Hooks return false if they manage to *resolve* the parameters
 505                 // This hook should be considered deprecated
 506                 wfDeprecated( 'ExtractThumbParameters', '1.22' );
 507                 return $params; // valid thumbnail URL (via extension or config)
 508         }
 509
 510         // FIXME: Files in the temp zone don't set a MIME type, which means
 511         // they don't have a handler. Which means we can't parse the param
 512         // string. However, not a big issue as what good is a param string
 513         // if you have no handler to make use of the param string and
 514         // actually generate the thumbnail.
 515         $handler = $file->getHandler();
 516
 517         // Based on UploadStash::parseKey
 518         $fileNamePos = strrpos( $thumbname, $params['f'] );
 519         if ( $fileNamePos === false ) {
 520                 // Maybe using a short filename? (see FileRepo::nameForThumb)
 521                 $fileNamePos = strrpos( $thumbname, 'thumbnail' );
 522         }
 523
 524         if ( $handler && $fileNamePos !== false ) {
 525                 $paramString = substr( $thumbname, 0, $fileNamePos - 1 );
 526                 $extraParams = $handler->parseParamString( $paramString );
 527                 if ( $extraParams !== false ) {
 528                         return $params + $extraParams;
 529                 }
 530         }
 531
 532         // As a last ditch fallback, use the traditional common parameters
 533         if ( preg_match( '!^(page(\d*)-)*(\d*)px-[^/]*$!', $thumbname, $matches ) ) {
 534                 list( /* all */, $pagefull, $pagenum, $size ) = $matches;
 535                 $params['width'] = $size;
 536                 if ( $pagenum ) {
 537                         $params['page'] = $pagenum;
 538                 }
 539                 return $params; // valid thumbnail URL
 540         }
 541         return null;
 542 }
 543
 544 /**
 545  * Output a thumbnail generation error message
 546  *
 547  * @param int $status
 548  * @param string $msg HTML
 549  * @return void
 550  */
 551 function wfThumbError( $status, $msg ) {
 552         global $wgShowHostnames;
 553
 554         header( 'Cache-Control: no-cache' );
 555         header( 'Content-Type: text/html; charset=utf-8' );
 556         if ( $status == 400 ) {
 557                 HttpStatus::header( 400 );
 558         } elseif ( $status == 404 ) {
 559                 HttpStatus::header( 404 );
 560         } elseif ( $status == 403 ) {
 561                 HttpStatus::header( 403 );
 562                 header( 'Vary: Cookie' );
 563         } else {
 564                 HttpStatus::header( 500 );
 565         }
 566         if ( $wgShowHostnames ) {
 567                 header( 'X-MW-Thumbnail-Renderer: ' . wfHostname() );
 568                 $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 569                 $hostname = htmlspecialchars( wfHostname() );
 570                 $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 571         } else {
 572                 $debug = '';
 573         }
 574         echo <<<EOT
 575 <!DOCTYPE html>
 576 <html><head>
 577 <meta charset="UTF-8" />
 578 <title>Error generating thumbnail</title>
 579 </head>
 580 <body>
 581 <h1>Error generating thumbnail</h1>
 582 <p>
 583 $msg
 584 </p>
 585 $debug
 586 </body>
 587 </html>
 588
 589 EOT;
 590 }