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         wfThumbHandleRequest();
  36 }
  37
  38 wfLogProfilingData();
  39
  40 //--------------------------------------------------------------------------
  41
  42 /**
  43  * Handle a thumbnail request via query parameters
  44  *
  45  * @return void
  46  */
  47 function wfThumbHandleRequest() {
  48         $params = get_magic_quotes_gpc()
  49                 ? array_map( 'stripslashes', $_GET )
  50                 : $_GET;
  51
  52         wfStreamThumb( $params ); // stream the thumbnail
  53 }
  54
  55 /**
  56  * Handle a thumbnail request via thumbnail file URL
  57  *
  58  * @return void
  59  */
  60 function wfThumbHandle404() {
  61         global $wgArticlePath;
  62
  63         # Set action base paths so that WebRequest::getPathInfo()
  64         # recognizes the "X" as the 'title' in ../thumb_handler.php/X urls.
  65         # Note: If Custom per-extension repo paths are set, this may break.
  66         $repo = RepoGroup::singleton()->getLocalRepo();
  67         $oldArticlePath = $wgArticlePath;
  68         $wgArticlePath = $repo->getZoneUrl( 'thumb' ) . '/$1';
  69
  70         $matches = WebRequest::getPathInfo();
  71
  72         $wgArticlePath = $oldArticlePath;
  73
  74         if ( !isset( $matches['title'] ) ) {
  75                 wfThumbError( 404, 'Could not determine the name of the requested thumbnail.' );
  76                 return;
  77         }
  78
  79         $params = wfExtractThumbRequestInfo( $matches['title'] ); // basic wiki URL param extracting
  80         if ( $params == null ) {
  81                 wfThumbError( 400, 'The specified thumbnail parameters are not recognized.' );
  82                 return;
  83         }
  84
  85         wfStreamThumb( $params ); // stream the thumbnail
  86 }
  87
  88 /**
  89  * Stream a thumbnail specified by parameters
  90  *
  91  * @param array $params List of thumbnailing parameters. In addition to parameters
  92  *  passed to the MediaHandler, this may also includes the keys:
  93  *   f (for filename), archived (if archived file), temp (if temp file),
  94  *   w (alias for width), p (alias for page), r (ignored; historical),
  95  *   rel404 (path for render on 404 to verify hash path correct),
  96  *   thumbName (thumbnail name to potentially extract more parameters from
  97  *   e.g. 'lossy-page1-120px-Foo.tiff' would add page, lossy and width
  98  *   to the parameters)
  99  * @return void
 100  */
 101 function wfStreamThumb( array $params ) {
 102         global $wgVaryOnXFP;
 103
 104         $section = new ProfileSection( __METHOD__ );
 105
 106         $headers = array(); // HTTP headers to send
 107
 108         $fileName = isset( $params['f'] ) ? $params['f'] : '';
 109
 110         // Backwards compatibility parameters
 111         if ( isset( $params['w'] ) ) {
 112                 $params['width'] = $params['w'];
 113                 unset( $params['w'] );
 114         }
 115         if ( isset( $params['p'] ) ) {
 116                 $params['page'] = $params['p'];
 117         }
 118
 119         // Is this a thumb of an archived file?
 120         $isOld = ( isset( $params['archived'] ) && $params['archived'] );
 121         unset( $params['archived'] ); // handlers don't care
 122
 123         // Is this a thumb of a temp file?
 124         $isTemp = ( isset( $params['temp'] ) && $params['temp'] );
 125         unset( $params['temp'] ); // handlers don't care
 126
 127         // Some basic input validation
 128         $fileName = strtr( $fileName, '\\/', '__' );
 129
 130         // Actually fetch the image. Method depends on whether it is archived or not.
 131         if ( $isTemp ) {
 132                 $repo = RepoGroup::singleton()->getLocalRepo()->getTempRepo();
 133                 $img = new UnregisteredLocalFile( null, $repo,
 134                         # Temp files are hashed based on the name without the timestamp.
 135                         # The thumbnails will be hashed based on the entire name however.
 136                         # @todo fix this convention to actually be reasonable.
 137                         $repo->getZonePath( 'public' ) . '/' . $repo->getTempHashPath( $fileName ) . $fileName
 138                 );
 139         } elseif ( $isOld ) {
 140                 // Format is <timestamp>!<name>
 141                 $bits = explode( '!', $fileName, 2 );
 142                 if ( count( $bits ) != 2 ) {
 143                         wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 144                         return;
 145                 }
 146                 $title = Title::makeTitleSafe( NS_FILE, $bits[1] );
 147                 if ( !$title ) {
 148                         wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 149                         return;
 150                 }
 151                 $img = RepoGroup::singleton()->getLocalRepo()->newFromArchiveName( $title, $fileName );
 152         } else {
 153                 $img = wfLocalFile( $fileName );
 154         }
 155
 156         // Check the source file title
 157         if ( !$img ) {
 158                 wfThumbError( 404, wfMessage( 'badtitletext' )->text() );
 159                 return;
 160         }
 161
 162         // Check permissions if there are read restrictions
 163         $varyHeader = array();
 164         if ( !in_array( 'read', User::getGroupPermissions( array( '*' ) ), true ) ) {
 165                 if ( !$img->getTitle() || !$img->getTitle()->userCan( 'read' ) ) {
 166                         wfThumbError( 403, 'Access denied. You do not have permission to access ' .
 167                                 'the source file.' );
 168                         return;
 169                 }
 170                 $headers[] = 'Cache-Control: private';
 171                 $varyHeader[] = 'Cookie';
 172         }
 173
 174         // Do rendering parameters extraction from thumbnail name.
 175         if ( isset( $params['thumbName'] ) ) {
 176                 $params = wfExtractThumbParams( $img, $params );
 177         }
 178         if ( $params == null ) {
 179                 wfThumbError( 400, 'The specified thumbnail parameters are not recognized.' );
 180                 return;
 181         }
 182
 183         // Check the source file storage path
 184         if ( !$img->exists() ) {
 185                 $redirectedLocation = false;
 186                 if ( !$isTemp ) {
 187                         // Check for file redirect
 188                         // Since redirects are associated with pages, not versions of files,
 189                         // we look for the most current version to see if its a redirect.
 190                         $possRedirFile = RepoGroup::singleton()->getLocalRepo()->findFile( $img->getName() );
 191                         if ( $possRedirFile && !is_null( $possRedirFile->getRedirected() ) ) {
 192                                 $redirTarget = $possRedirFile->getName();
 193                                 $targetFile = wfLocalFile( Title::makeTitleSafe( NS_FILE, $redirTarget ) );
 194                                 if ( $targetFile->exists() ) {
 195                                         $newThumbName = $targetFile->thumbName( $params );
 196                                         if ( $isOld ) {
 197                                                 $newThumbUrl = $targetFile->getArchiveThumbUrl(
 198                                                         $bits[0] . '!' . $targetFile->getName(), $newThumbName );
 199                                         } else {
 200                                                 $newThumbUrl = $targetFile->getThumbUrl( $newThumbName );
 201                                         }
 202                                         $redirectedLocation = wfExpandUrl( $newThumbUrl, PROTO_CURRENT );
 203                                 }
 204                         }
 205                 }
 206
 207                 if ( $redirectedLocation ) {
 208                         // File has been moved. Give redirect.
 209                         $response = RequestContext::getMain()->getRequest()->response();
 210                         $response->header( "HTTP/1.1 302 " . HttpStatus::getMessage( 302 ) );
 211                         $response->header( 'Location: ' . $redirectedLocation );
 212                         $response->header( 'Expires: ' .
 213                                 gmdate( 'D, d M Y H:i:s', time() + 12 * 3600 ) . ' GMT' );
 214                         if ( $wgVaryOnXFP ) {
 215                                 $varyHeader[] = 'X-Forwarded-Proto';
 216                         }
 217                         if ( count( $varyHeader ) ) {
 218                                 $response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
 219                         }
 220                         return;
 221                 }
 222
 223                 // If its not a redirect that has a target as a local file, give 404.
 224                 wfThumbError( 404, "The source file '$fileName' does not exist." );
 225                 return;
 226         } elseif ( $img->getPath() === false ) {
 227                 wfThumbError( 500, "The source file '$fileName' is not locally accessible." );
 228                 return;
 229         }
 230
 231         // Check IMS against the source file
 232         // This means that clients can keep a cached copy even after it has been deleted on the server
 233         if ( !empty( $_SERVER['HTTP_IF_MODIFIED_SINCE'] ) ) {
 234                 // Fix IE brokenness
 235                 $imsString = preg_replace( '/;.*$/', '', $_SERVER["HTTP_IF_MODIFIED_SINCE"] );
 236                 // Calculate time
 237                 wfSuppressWarnings();
 238                 $imsUnix = strtotime( $imsString );
 239                 wfRestoreWarnings();
 240                 if ( wfTimestamp( TS_UNIX, $img->getTimestamp() ) <= $imsUnix ) {
 241                         header( 'HTTP/1.1 304 Not Modified' );
 242                         return;
 243                 }
 244         }
 245
 246         $rel404 = isset( $params['rel404'] ) ? $params['rel404'] : null;
 247         unset( $params['r'] ); // ignore 'r' because we unconditionally pass File::RENDER
 248         unset( $params['f'] ); // We're done with 'f' parameter.
 249         unset( $params['rel404'] ); // moved to $rel404
 250
 251         // Get the normalized thumbnail name from the parameters...
 252         try {
 253                 $thumbName = $img->thumbName( $params );
 254                 if ( !strlen( $thumbName ) ) { // invalid params?
 255                         wfThumbError( 400, 'The specified thumbnail parameters are not valid.' );
 256                         return;
 257                 }
 258                 $thumbName2 = $img->thumbName( $params, File::THUMB_FULL_NAME ); // b/c; "long" style
 259         } catch ( MWException $e ) {
 260                 wfThumbError( 500, $e->getHTML() );
 261                 return;
 262         }
 263
 264         // For 404 handled thumbnails, we only use the the base name of the URI
 265         // for the thumb params and the parent directory for the source file name.
 266         // Check that the zone relative path matches up so squid caches won't pick
 267         // up thumbs that would not be purged on source file deletion (bug 34231).
 268         if ( $rel404 !== null ) { // thumbnail was handled via 404
 269                 if ( rawurldecode( $rel404 ) === $img->getThumbRel( $thumbName ) ) {
 270                         // Request for the canonical thumbnail name
 271                 } elseif ( rawurldecode( $rel404 ) === $img->getThumbRel( $thumbName2 ) ) {
 272                         // Request for the "long" thumbnail name; redirect to canonical name
 273                         $response = RequestContext::getMain()->getRequest()->response();
 274                         $response->header( "HTTP/1.1 301 " . HttpStatus::getMessage( 301 ) );
 275                         $response->header( 'Location: ' .
 276                                 wfExpandUrl( $img->getThumbUrl( $thumbName ), PROTO_CURRENT ) );
 277                         $response->header( 'Expires: ' .
 278                                 gmdate( 'D, d M Y H:i:s', time() + 7 * 86400 ) . ' GMT' );
 279                         if ( $wgVaryOnXFP ) {
 280                                 $varyHeader[] = 'X-Forwarded-Proto';
 281                         }
 282                         if ( count( $varyHeader ) ) {
 283                                 $response->header( 'Vary: ' . implode( ', ', $varyHeader ) );
 284                         }
 285                         return;
 286                 } else {
 287                         wfThumbError( 404, "The given path of the specified thumbnail is incorrect;
 288                                 expected '" . $img->getThumbRel( $thumbName ) . "' but got '" .
 289                                 rawurldecode( $rel404 ) . "'." );
 290                         return;
 291                 }
 292         }
 293
 294         $dispositionType = isset( $params['download'] ) ? 'attachment' : 'inline';
 295
 296         // Suggest a good name for users downloading this thumbnail
 297         $headers[] = "Content-Disposition: {$img->getThumbDisposition( $thumbName, $dispositionType )}";
 298
 299         if ( count( $varyHeader ) ) {
 300                 $headers[] = 'Vary: ' . implode( ', ', $varyHeader );
 301         }
 302
 303         // Stream the file if it exists already...
 304         $thumbPath = $img->getThumbPath( $thumbName );
 305         if ( $img->getRepo()->fileExists( $thumbPath ) ) {
 306                 $img->getRepo()->streamFile( $thumbPath, $headers );
 307                 return;
 308         }
 309
 310         $user = RequestContext::getMain()->getUser();
 311         if ( !wfThumbIsStandard( $img, $params ) && $user->pingLimiter( 'renderfile-nonstandard' ) ) {
 312                 wfThumbError( 500, wfMessage( 'actionthrottledtext' ) );
 313                 return;
 314         } elseif ( $user->pingLimiter( 'renderfile' ) ) {
 315                 wfThumbError( 500, wfMessage( 'actionthrottledtext' ) );
 316                 return;
 317         } elseif ( wfThumbIsAttemptThrottled( $img, $thumbName, 5 ) ) {
 318                 wfThumbError( 500, wfMessage( 'thumbnail_image-failure-limit', 5 ) );
 319                 return;
 320         }
 321
 322         // Thumbnail isn't already there, so create the new thumbnail...
 323         $thumb = null;
 324         try {
 325                 // Record failures on PHP fatals too
 326                 register_shutdown_function( function() use ( &$thumb, $img, $thumbName ) {
 327                         if ( $thumb === null ) { // transform() gave a fatal
 328                                 wfThumbIncrAttemptFailures( $img, $thumbName );
 329                         }
 330                 } );
 331                 $thumb = $img->transform( $params, File::RENDER_NOW );
 332         } catch ( Exception $ex ) {
 333                 // Tried to select a page on a non-paged file?
 334                 $thumb = false;
 335         }
 336
 337         // Check for thumbnail generation errors...
 338         $errorMsg = false;
 339         $msg = wfMessage( 'thumbnail_error' );
 340         if ( !$thumb ) {
 341                 $errorMsg = $msg->rawParams( 'File::transform() returned false' )->escaped();
 342         } elseif ( $thumb->isError() ) {
 343                 $errorMsg = $thumb->getHtmlMsg();
 344         } elseif ( !$thumb->hasFile() ) {
 345                 $errorMsg = $msg->rawParams( 'No path supplied in thumbnail object' )->escaped();
 346         } elseif ( $thumb->fileIsSource() ) {
 347                 $errorMsg = $msg->
 348                         rawParams( 'Image was not scaled, is the requested width bigger than the source?' )->escaped();
 349         }
 350
 351         if ( $errorMsg !== false ) {
 352                 wfThumbIncrAttemptFailures( $img, $thumbName );
 353                 wfThumbError( 500, $errorMsg );
 354         } else {
 355                 // Stream the file if there were no errors
 356                 $thumb->streamFile( $headers );
 357         }
 358 }
 359
 360 /**
 361  * Returns true if this thumbnail is one that MediaWiki generates
 362  * links to on file description pages and possibly parser output.
 363  *
 364  * $params is considered non-standard if they involve a non-standard
 365  * width or any parameter aside from width and page number. The number
 366  * of possible files with standard parameters is far less than that of all
 367  * possible combinations; rate-limiting for them can thus be more generious.
 368  *
 369  * @param File $img
 370  * @param array $params
 371  * @return bool
 372  */
 373 function wfThumbIsStandard( File $img, array $params ) {
 374         global $wgThumbLimits, $wgImageLimits;
 375         // @TODO: use polymorphism with media handler here
 376         if ( array_diff( array_keys( $params ), array( 'width', 'page' ) ) ) {
 377                 return false; // extra parameters present
 378         }
 379         if ( isset( $params['width'] ) ) {
 380                 $widths = $wgThumbLimits;
 381                 foreach ( $wgImageLimits as $pair ) {
 382                         $widths[] = $pair[0];
 383                 }
 384                 if ( !in_array( $params['width'], $widths ) ) {
 385                         return false;
 386                 }
 387         }
 388         return true;
 389 }
 390
 391 /**
 392  * @param File $img
 393  * @param string $thumbName
 394  * @param int $limit
 395  * @return int|bool
 396  */
 397 function wfThumbIsAttemptThrottled( File $img, $thumbName, $limit ) {
 398         global $wgMemc;
 399
 400         return ( $wgMemc->get( wfThumbAttemptKey( $img, $thumbName ) ) >= $limit );
 401 }
 402
 403 /**
 404  * @param File $img
 405  * @param string $thumbName
 406  */
 407 function wfThumbIncrAttemptFailures( File $img, $thumbName ) {
 408         global $wgMemc;
 409
 410         $key = wfThumbAttemptKey( $img, $thumbName );
 411         if ( !$wgMemc->incr( $key, 1 ) ) {
 412                 if ( !$wgMemc->add( $key, 1, 3600 ) ) {
 413                         $wgMemc->incr( $key, 1 );
 414                 }
 415         }
 416 }
 417
 418 /**
 419  * @param File $img
 420  * @param string $thumbName
 421  * @return string
 422  */
 423 function wfThumbAttemptKey( File $img, $thumbName ) {
 424         global $wgAttemptFailureEpoch;
 425
 426         return wfMemcKey( 'attempt-failures', $wgAttemptFailureEpoch,
 427                 $img->getRepo()->getName(), md5( $img->getName() ), md5( $thumbName ) );
 428 }
 429
 430 /**
 431  * Convert pathinfo type parameter, into normal request parameters
 432  *
 433  * So for example, if the request was redirected from
 434  * /w/images/thumb/a/ab/Foo.png/120px-Foo.png. The $thumbRel parameter
 435  * of this function would be set to "a/ab/Foo.png/120px-Foo.png".
 436  * This method is responsible for turning that into an array
 437  * with the folowing keys:
 438  *  * f => the filename (Foo.png)
 439  *  * rel404 => the whole thing (a/ab/Foo.png/120px-Foo.png)
 440  *  * archived => 1 (If the request is for an archived thumb)
 441  *  * temp => 1 (If the file is in the "temporary" zone)
 442  *  * thumbName => the thumbnail name, including parameters (120px-Foo.png)
 443  *
 444  * Transform specific parameters are set later via wfExtractThumbParams().
 445  *
 446  * @param string $thumbRel Thumbnail path relative to the thumb zone
 447  * @return array|null Associative params array or null
 448  */
 449 function wfExtractThumbRequestInfo( $thumbRel ) {
 450         $repo = RepoGroup::singleton()->getLocalRepo();
 451
 452         $hashDirReg = $subdirReg = '';
 453         for ( $i = 0; $i < $repo->getHashLevels(); $i++ ) {
 454                 $subdirReg .= '[0-9a-f]';
 455                 $hashDirReg .= "$subdirReg/";
 456         }
 457
 458         // Check if this is a thumbnail of an original in the local file repo
 459         if ( preg_match( "!^((archive/)?$hashDirReg([^/]*)/([^/]*))$!", $thumbRel, $m ) ) {
 460                 list( /*all*/, $rel, $archOrTemp, $filename, $thumbname ) = $m;
 461         // Check if this is a thumbnail of an temp file in the local file repo
 462         } elseif ( preg_match( "!^(temp/)($hashDirReg([^/]*)/([^/]*))$!", $thumbRel, $m ) ) {
 463                 list( /*all*/, $archOrTemp, $rel, $filename, $thumbname ) = $m;
 464         } else {
 465                 return null; // not a valid looking thumbnail request
 466         }
 467
 468         $params = array( 'f' => $filename, 'rel404' => $rel );
 469         if ( $archOrTemp === 'archive/' ) {
 470                 $params['archived'] = 1;
 471         } elseif ( $archOrTemp === 'temp/' ) {
 472                 $params['temp'] = 1;
 473         }
 474
 475         $params['thumbName'] = $thumbname;
 476         return $params;
 477 }
 478
 479 /**
 480  * Convert a thumbnail name (122px-foo.png) to parameters, using
 481  * file handler.
 482  *
 483  * @param File $file File object for file in question
 484  * @param array $param Array of parameters so far
 485  * @return array Parameters array with more parameters
 486  */
 487 function wfExtractThumbParams( $file, $params ) {
 488         if ( !isset( $params['thumbName'] ) ) {
 489                 throw new MWException( "No thumbnail name passed to wfExtractThumbParams" );
 490         }
 491
 492         $thumbname = $params['thumbName'];
 493         unset( $params['thumbName'] );
 494
 495         // Do the hook first for older extensions that rely on it.
 496         if ( !wfRunHooks( 'ExtractThumbParameters', array( $thumbname, &$params ) ) ) {
 497                 // Check hooks if parameters can be extracted
 498                 // Hooks return false if they manage to *resolve* the parameters
 499                 // This hook should be considered deprecated
 500                 wfDeprecated( 'ExtractThumbParameters', '1.22' );
 501                 return $params; // valid thumbnail URL (via extension or config)
 502         }
 503
 504         // FIXME: Files in the temp zone don't set a mime type, which means
 505         // they don't have a handler. Which means we can't parse the param
 506         // string. However, not a big issue as what good is a param string
 507         // if you have no handler to make use of the param string and
 508         // actually generate the thumbnail.
 509         $handler = $file->getHandler();
 510
 511         // Based on UploadStash::parseKey
 512         $fileNamePos = strrpos( $thumbname, $params['f'] );
 513         if ( $fileNamePos === false ) {
 514                 // Maybe using a short filename? (see FileRepo::nameForThumb)
 515                 $fileNamePos = strrpos( $thumbname, 'thumbnail' );
 516         }
 517
 518         if ( $handler && $fileNamePos !== false ) {
 519                 $paramString = substr( $thumbname, 0, $fileNamePos - 1 );
 520                 $extraParams = $handler->parseParamString( $paramString );
 521                 if ( $extraParams !== false ) {
 522                         return $params + $extraParams;
 523                 }
 524         }
 525
 526         // As a last ditch fallback, use the traditional common parameters
 527         if ( preg_match( '!^(page(\d*)-)*(\d*)px-[^/]*$!', $thumbname, $matches ) ) {
 528                 list( /* all */, $pagefull, $pagenum, $size ) = $matches;
 529                 $params['width'] = $size;
 530                 if ( $pagenum ) {
 531                         $params['page'] = $pagenum;
 532                 }
 533                 return $params; // valid thumbnail URL
 534         }
 535         return null;
 536 }
 537
 538 /**
 539  * Output a thumbnail generation error message
 540  *
 541  * @param int $status
 542  * @param string $msg
 543  * @return void
 544  */
 545 function wfThumbError( $status, $msg ) {
 546         global $wgShowHostnames;
 547
 548         header( 'Cache-Control: no-cache' );
 549         header( 'Content-Type: text/html; charset=utf-8' );
 550         if ( $status == 404 ) {
 551                 header( 'HTTP/1.1 404 Not found' );
 552         } elseif ( $status == 403 ) {
 553                 header( 'HTTP/1.1 403 Forbidden' );
 554                 header( 'Vary: Cookie' );
 555         } else {
 556                 header( 'HTTP/1.1 500 Internal server error' );
 557         }
 558         if ( $wgShowHostnames ) {
 559                 header( 'X-MW-Thumbnail-Renderer: ' . wfHostname() );
 560                 $url = htmlspecialchars( isset( $_SERVER['REQUEST_URI'] ) ? $_SERVER['REQUEST_URI'] : '' );
 561                 $hostname = htmlspecialchars( wfHostname() );
 562                 $debug = "<!-- $url -->\n<!-- $hostname -->\n";
 563         } else {
 564                 $debug = '';
 565         }
 566         echo <<<EOT
 567 <html><head><title>Error generating thumbnail</title></head>
 568 <body>
 569 <h1>Error generating thumbnail</h1>
 570 <p>
 571 $msg
 572 </p>
 573 $debug
 574 </body>
 575 </html>
 576
 577 EOT;
 578 }