MediaWiki 1.7.1 wiederhergestellt

1 files changed, 695 insertions, 0 deletions

diff --git a/includes/MimeMagic.php b/includes/MimeMagic.php
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+++ b/includes/MimeMagic.php
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+<?php
+/** Module defining helper functions for detecting and dealing with mime types.
+ *
+ * @package MediaWiki
+ */
+
+ /** Defines a set of well known mime types
+ * This is used as a fallback to mime.types files.
+ * An extensive list of well known mime types is provided by
+ * the file mime.types in the includes directory.
+ */
+define('MM_WELL_KNOWN_MIME_TYPES',<<<END_STRING
+application/ogg ogg ogm
+application/pdf pdf
+application/x-javascript js
+application/x-shockwave-flash swf
+audio/midi mid midi kar
+audio/mpeg mpga mpa mp2 mp3
+audio/x-aiff aif aiff aifc
+audio/x-wav wav
+audio/ogg ogg
+image/x-bmp bmp
+image/gif gif
+image/jpeg jpeg jpg jpe
+image/png png
+image/svg+xml svg
+image/tiff tiff tif
+image/vnd.djvu djvu
+text/plain txt
+text/html html htm
+video/ogg ogm ogg
+video/mpeg mpg mpeg
+END_STRING
+);
+
+ /** Defines a set of well known mime info entries
+ * This is used as a fallback to mime.info files.
+ * An extensive list of well known mime types is provided by
+ * the file mime.info in the includes directory.
+ */
+define('MM_WELL_KNOWN_MIME_INFO', <<<END_STRING
+application/pdf [OFFICE]
+text/javascript application/x-javascript [EXECUTABLE]
+application/x-shockwave-flash [MULTIMEDIA]
+audio/midi [AUDIO]
+audio/x-aiff [AUDIO]
+audio/x-wav [AUDIO]
+audio/mp3 audio/mpeg [AUDIO]
+application/ogg audio/ogg video/ogg [MULTIMEDIA]
+image/x-bmp image/bmp [BITMAP]
+image/gif [BITMAP]
+image/jpeg [BITMAP]
+image/png [BITMAP]
+image/svg image/svg+xml [DRAWING]
+image/tiff [BITMAP]
+image/vnd.djvu [BITMAP]
+text/plain [TEXT]
+text/html [TEXT]
+video/ogg [VIDEO]
+video/mpeg [VIDEO]
+unknown/unknown application/octet-stream application/x-empty [UNKNOWN]
+END_STRING
+);
+
+#note: because this file is possibly included by a function,
+#we need to access the global scope explicitely!
+global $wgLoadFileinfoExtension;
+
+if ($wgLoadFileinfoExtension) {
+	if(!extension_loaded('fileinfo')) dl('fileinfo.' . PHP_SHLIB_SUFFIX);
+}
+
+/** Implements functions related to mime types such as detection and mapping to
+* file extension,
+*
+* Instances of this class are stateles, there only needs to be one global instance
+* of MimeMagic. Please use wfGetMimeMagic to get that instance.
+* @package MediaWiki
+*/
+class MimeMagic {
+
+	/**
+	* Mapping of media types to arrays of mime types.
+	* This is used by findMediaType and getMediaType, respectively
+	*/
+	var $mMediaTypes= NULL;
+
+	/** Map of mime type aliases
+	*/
+	var $mMimeTypeAliases= NULL;
+
+	/** map of mime types to file extensions (as a space seprarated list)
+	*/
+	var $mMimeToExt= NULL;
+
+	/** map of file extensions types to mime types (as a space seprarated list)
+	*/
+	var $mExtToMime= NULL;
+
+	/** Initializes the MimeMagic object. This is called by wfGetMimeMagic when instantiation
+	* the global MimeMagic singleton object.
+	*
+	* This constructor parses the mime.types and mime.info files and build internal mappings.
+	*/
+	function MimeMagic() {
+		/*
+		*   --- load mime.types ---
+		*/
+
+		global $wgMimeTypeFile;
+
+		$types= MM_WELL_KNOWN_MIME_TYPES;
+
+		if ($wgMimeTypeFile) {
+			if (is_file($wgMimeTypeFile) and is_readable($wgMimeTypeFile)) {
+				wfDebug("MimeMagic::MimeMagic: loading mime types from $wgMimeTypeFile\n");
+
+				$types.= "\n";
+				$types.= file_get_contents($wgMimeTypeFile);
+			}
+			else wfDebug("MimeMagic::MimeMagic: can't load mime types from $wgMimeTypeFile\n");
+		}
+		else wfDebug("MimeMagic::MimeMagic: no mime types file defined, using build-ins only.\n");
+
+		$types= str_replace(array("\r\n","\n\r","\n\n","\r\r","\r"),"\n",$types);
+		$types= str_replace("\t"," ",$types);
+
+		$this->mMimeToExt= array();
+		$this->mToMime= array();
+
+		$lines= explode("\n",$types);
+		foreach ($lines as $s) {
+			$s= trim($s);
+			if (empty($s)) continue;
+			if (strpos($s,'#')===0) continue;
+
+			$s= strtolower($s);
+			$i= strpos($s,' ');
+
+			if ($i===false) continue;
+
+			#print "processing MIME line $s<br>";
+
+			$mime= substr($s,0,$i);
+			$ext= trim(substr($s,$i+1));
+
+			if (empty($ext)) continue;
+
+			if (@$this->mMimeToExt[$mime]) $this->mMimeToExt[$mime] .= ' '.$ext;
+			else $this->mMimeToExt[$mime]= $ext;
+
+			$extensions= explode(' ',$ext);
+
+			foreach ($extensions as $e) {
+				$e= trim($e);
+				if (empty($e)) continue;
+
+				if (@$this->mExtToMime[$e]) $this->mExtToMime[$e] .= ' '.$mime;
+				else $this->mExtToMime[$e]= $mime;
+			}
+		}
+
+		/*
+		*   --- load mime.info ---
+		*/
+
+		global $wgMimeInfoFile;
+
+		$info= MM_WELL_KNOWN_MIME_INFO;
+
+		if ($wgMimeInfoFile) {
+			if (is_file($wgMimeInfoFile) and is_readable($wgMimeInfoFile)) {
+				wfDebug("MimeMagic::MimeMagic: loading mime info from $wgMimeInfoFile\n");
+
+				$info.= "\n";
+				$info.= file_get_contents($wgMimeInfoFile);
+			}
+			else wfDebug("MimeMagic::MimeMagic: can't load mime info from $wgMimeInfoFile\n");
+		}
+		else wfDebug("MimeMagic::MimeMagic: no mime info file defined, using build-ins only.\n");
+
+		$info= str_replace(array("\r\n","\n\r","\n\n","\r\r","\r"),"\n",$info);
+		$info= str_replace("\t"," ",$info);
+
+		$this->mMimeTypeAliases= array();
+		$this->mMediaTypes= array();
+
+		$lines= explode("\n",$info);
+		foreach ($lines as $s) {
+			$s= trim($s);
+			if (empty($s)) continue;
+			if (strpos($s,'#')===0) continue;
+
+			$s= strtolower($s);
+			$i= strpos($s,' ');
+
+			if ($i===false) continue;
+
+			#print "processing MIME INFO line $s<br>";
+
+			$match= array();
+			if (preg_match('!\[\s*(\w+)\s*\]!',$s,$match)) {
+				$s= preg_replace('!\[\s*(\w+)\s*\]!','',$s);
+				$mtype= trim(strtoupper($match[1]));
+			}
+			else $mtype= MEDIATYPE_UNKNOWN;
+
+			$m= explode(' ',$s);
+
+			if (!isset($this->mMediaTypes[$mtype])) $this->mMediaTypes[$mtype]= array();
+
+			foreach ($m as $mime) {
+				$mime= trim($mime);
+				if (empty($mime)) continue;
+
+				$this->mMediaTypes[$mtype][]= $mime;
+			}
+
+			if (sizeof($m)>1) {
+				$main= $m[0];
+				for ($i=1; $i<sizeof($m); $i+= 1) {
+					$mime= $m[$i];
+					$this->mMimeTypeAliases[$mime]= $main;
+				}
+			}
+		}
+
+	}
+
+	/** returns a list of file extensions for a given mime type
+	* as a space separated string.
+	*/
+	function getExtensionsForType($mime) {
+		$mime= strtolower($mime);
+
+		$r= @$this->mMimeToExt[$mime];
+
+		if (@!$r and isset($this->mMimeTypeAliases[$mime])) {
+			$mime= $this->mMimeTypeAliases[$mime];
+			$r= @$this->mMimeToExt[$mime];
+		}
+
+		return $r;
+	}
+
+	/** returns a list of mime types for a given file extension
+	* as a space separated string.
+	*/
+	function getTypesForExtension($ext) {
+		$ext= strtolower($ext);
+
+		$r= @$this->mExtToMime[$ext];
+		return $r;
+	}
+
+	/** returns a single mime type for a given file extension.
+	* This is always the first type from the list returned by getTypesForExtension($ext).
+	*/
+	function guessTypesForExtension($ext) {
+		$m= $this->getTypesForExtension( $ext );
+		if( is_null($m) ) return NULL;
+
+		$m= trim( $m );
+		$m= preg_replace('/\s.*$/','',$m);
+
+		return $m;
+	}
+
+
+	/** tests if the extension matches the given mime type.
+	* returns true if a match was found, NULL if the mime type is unknown,
+	* and false if the mime type is known but no matches where found.
+	*/
+	function isMatchingExtension($extension,$mime) {
+		$ext= $this->getExtensionsForType($mime);
+
+		if (!$ext) {
+			return NULL;  //unknown
+		}
+
+		$ext= explode(' ',$ext);
+
+		$extension= strtolower($extension);
+ 		if (in_array($extension,$ext)) {
+			return true;
+		}
+
+		return false;
+	}
+
+	/** returns true if the mime type is known to represent
+	* an image format supported by the PHP GD library.
+	*/
+	function isPHPImageType( $mime ) {
+		#as defined by imagegetsize and image_type_to_mime
+		static $types = array(
+			'image/gif', 'image/jpeg', 'image/png',
+			'image/x-bmp', 'image/xbm', 'image/tiff',
+			'image/jp2', 'image/jpeg2000', 'image/iff',
+			'image/xbm', 'image/x-xbitmap',
+			'image/vnd.wap.wbmp', 'image/vnd.xiff',
+			'image/x-photoshop',
+			'application/x-shockwave-flash',
+		);
+
+		return in_array( $mime, $types );
+	}
+
+	/**
+	 * Returns true if the extension represents a type which can
+	 * be reliably detected from its content. Use this to determine
+	 * whether strict content checks should be applied to reject
+	 * invalid uploads; if we can't identify the type we won't
+	 * be able to say if it's invalid.
+	 *
+	 * @todo Be more accurate when using fancy mime detector plugins;
+	 *       right now this is the bare minimum getimagesize() list.
+	 * @return bool
+	 */
+	function isRecognizableExtension( $extension ) {
+		static $types = array(
+			'gif', 'jpeg', 'jpg', 'png', 'swf', 'psd',
+			'bmp', 'tiff', 'tif', 'jpc', 'jp2',
+			'jpx', 'jb2', 'swc', 'iff', 'wbmp',
+			'xbm', 'djvu'
+		);
+		return in_array( strtolower( $extension ), $types );
+	}
+
+
+	/** mime type detection. This uses detectMimeType to detect the mim type of the file,
+	* but applies additional checks to determine some well known file formats that may be missed
+	* or misinterpreter by the default mime detection (namely xml based formats like XHTML or SVG).
+	*
+	* @param string $file The file to check
+	* @param bool $useExt switch for allowing to use the file extension to guess the mime type. true by default.
+	*
+	* @return string the mime type of $file
+	*/
+	function guessMimeType( $file, $useExt=true ) {
+		$fname = 'MimeMagic::guessMimeType';
+		$mime= $this->detectMimeType($file,$useExt);
+
+		// Read a chunk of the file
+		$f = fopen( $file, "rt" );
+		if( !$f ) return "unknown/unknown";
+		$head = fread( $f, 1024 );
+		fclose( $f );
+
+		$sub4 =  substr( $head, 0, 4 );
+		if ( $sub4 == "\x01\x00\x09\x00" || $sub4 == "\xd7\xcd\xc6\x9a" ) {
+			// WMF kill kill kill
+			// Note that WMF may have a bare header, no magic number.
+			// The former of the above two checks is theoretically prone to false positives
+			$mime = "application/x-msmetafile";
+		}
+
+		if (strpos($mime,"text/")===0 || $mime==="application/xml") {
+
+			$xml_type= NULL;
+			$script_type= NULL;
+
+			/*
+			* look for XML formats (XHTML and SVG)
+			*/
+			if ($mime==="text/sgml" ||
+			    $mime==="text/plain" ||
+			    $mime==="text/html" ||
+			    $mime==="text/xml" ||
+		            $mime==="application/xml") {
+
+				if (substr($head,0,5)=="<?xml") $xml_type= "ASCII";
+				elseif (substr($head,0,8)=="\xef\xbb\xbf<?xml") $xml_type= "UTF-8";
+				elseif (substr($head,0,10)=="\xfe\xff\x00<\x00?\x00x\x00m\x00l") $xml_type= "UTF-16BE";
+				elseif (substr($head,0,10)=="\xff\xfe<\x00?\x00x\x00m\x00l\x00") $xml_type= "UTF-16LE";
+
+				if ($xml_type) {
+					if ($xml_type!=="UTF-8" && $xml_type!=="ASCII") $head= iconv($xml_type,"ASCII//IGNORE",$head);
+
+					$match= array();
+					$doctype= "";
+					$tag= "";
+
+					if (preg_match('%<!DOCTYPE\s+[\w-]+\s+PUBLIC\s+["'."'".'"](.*?)["'."'".'"].*>%sim',$head,$match)) $doctype= $match[1];
+					if (preg_match('%<(\w+).*>%sim',$head,$match)) $tag= $match[1];
+
+					#print "<br>ANALYSING $file ($mime): doctype= $doctype; tag= $tag<br>";
+
+					if (strpos($doctype,"-//W3C//DTD SVG")===0) $mime= "image/svg";
+					elseif ($tag==="svg") $mime= "image/svg";
+					elseif (strpos($doctype,"-//W3C//DTD XHTML")===0) $mime= "text/html";
+					elseif ($tag==="html") $mime= "text/html";
+
+					$test_more= false;
+				}
+			}
+
+			/*
+			* look for shell scripts
+			*/
+			if (!$xml_type) {
+				$script_type= NULL;
+
+				#detect by shebang
+				if (substr($head,0,2)=="#!") $script_type= "ASCII";
+				elseif (substr($head,0,5)=="\xef\xbb\xbf#!") $script_type= "UTF-8";
+				elseif (substr($head,0,7)=="\xfe\xff\x00#\x00!") $script_type= "UTF-16BE";
+				elseif (substr($head,0,7)=="\xff\xfe#\x00!") $script_type= "UTF-16LE";
+
+				if ($script_type) {
+					if ($script_type!=="UTF-8" && $script_type!=="ASCII") $head= iconv($script_type,"ASCII//IGNORE",$head);
+
+					$match= array();
+					$prog= "";
+
+					if (preg_match('%/?([^\s]+/)(w+)%sim',$head,$match)) $script= $match[2];
+
+					$mime= "application/x-$prog";
+				}
+			}
+
+			/*
+			* look for PHP
+			*/
+			if( !$xml_type && !$script_type ) {
+
+				if( ( strpos( $head, '<?php' ) !== false ) ||
+				    ( strpos( $head, '<? ' ) !== false ) ||
+				    ( strpos( $head, "<?\n" ) !== false ) ||
+				    ( strpos( $head, "<?\t" ) !== false ) ||
+				    ( strpos( $head, "<?=" ) !== false ) ||
+
+				    ( strpos( $head, "<\x00?\x00p\x00h\x00p" ) !== false ) ||
+				    ( strpos( $head, "<\x00?\x00 " ) !== false ) ||
+				    ( strpos( $head, "<\x00?\x00\n" ) !== false ) ||
+				    ( strpos( $head, "<\x00?\x00\t" ) !== false ) ||
+				    ( strpos( $head, "<\x00?\x00=" ) !== false ) ) {
+
+					$mime= "application/x-php";
+				}
+			}
+
+		}
+
+		if (isset($this->mMimeTypeAliases[$mime])) $mime= $this->mMimeTypeAliases[$mime];
+
+		wfDebug("$fname: final mime type of $file: $mime\n");
+		return $mime;
+	}
+
+	/** Internal mime type detection, please use guessMimeType() for application code instead.
+	* Detection is done using an external program, if $wgMimeDetectorCommand is set.
+	* Otherwise, the fileinfo extension and mime_content_type are tried (in this order), if they are available.
+	* If the dections fails and $useExt is true, the mime type is guessed from the file extension, using guessTypesForExtension.
+	* If the mime type is still unknown, getimagesize is used to detect the mime type if the file is an image.
+	* If no mime type can be determined, this function returns "unknown/unknown".
+	*
+	* @param string $file The file to check
+	* @param bool $useExt switch for allowing to use the file extension to guess the mime type. true by default.
+	*
+	* @return string the mime type of $file
+	* @access private
+	*/
+	function detectMimeType( $file, $useExt=true ) {
+		$fname = 'MimeMagic::detectMimeType';
+
+		global $wgMimeDetectorCommand;
+
+		$m= NULL;
+		if ($wgMimeDetectorCommand) {
+			$fn= wfEscapeShellArg($file);
+			$m= `$wgMimeDetectorCommand $fn`;
+		}
+		else if (function_exists("finfo_open") && function_exists("finfo_file")) {
+
+			# This required the fileinfo extension by PECL,
+			# see http://pecl.php.net/package/fileinfo
+			# This must be compiled into PHP
+			#
+			# finfo is the official replacement for the deprecated
+			# mime_content_type function, see below.
+			#
+			# If you may need to load the fileinfo extension at runtime, set
+			# $wgLoadFileinfoExtension in LocalSettings.php
+
+			$mime_magic_resource = finfo_open(FILEINFO_MIME); /* return mime type ala mimetype extension */
+
+			if ($mime_magic_resource) {
+				$m= finfo_file($mime_magic_resource, $file);
+
+				finfo_close($mime_magic_resource);
+			}
+			else wfDebug("$fname: finfo_open failed on ".FILEINFO_MIME."!\n");
+		}
+		else if (function_exists("mime_content_type")) {
+
+			# NOTE: this function is available since PHP 4.3.0, but only if
+			# PHP was compiled with --with-mime-magic or, before 4.3.2, with --enable-mime-magic.
+			#
+			# On Winodws, you must set mime_magic.magicfile in php.ini to point to the mime.magic file bundeled with PHP;
+			# sometimes, this may even be needed under linus/unix.
+			#
+			# Also note that this has been DEPRECATED in favor of the fileinfo extension by PECL, see above.
+			# see http://www.php.net/manual/en/ref.mime-magic.php for details.
+
+			$m= mime_content_type($file);
+		}
+		else wfDebug("$fname: no magic mime detector found!\n");
+
+		if ($m) {
+			#normalize
+			$m= preg_replace('![;, ].*$!','',$m); #strip charset, etc
+			$m= trim($m);
+			$m= strtolower($m);
+
+			if (strpos($m,'unknown')!==false) $m= NULL;
+			else {
+				wfDebug("$fname: magic mime type of $file: $m\n");
+				return $m;
+			}
+		}
+
+		#if still not known, use getimagesize to find out the type of image
+		#TODO: skip things that do not have a well-known image extension? Would that be safe?
+		wfSuppressWarnings();
+		$gis = getimagesize( $file );
+		wfRestoreWarnings();
+
+		$notAnImage= false;
+
+		if ($gis && is_array($gis) && $gis[2]) {
+			switch ($gis[2]) {
+				case IMAGETYPE_GIF: $m= "image/gif"; break;
+				case IMAGETYPE_JPEG: $m= "image/jpeg"; break;
+				case IMAGETYPE_PNG: $m= "image/png"; break;
+				case IMAGETYPE_SWF: $m= "application/x-shockwave-flash"; break;
+				case IMAGETYPE_PSD: $m= "application/photoshop"; break;
+				case IMAGETYPE_BMP: $m= "image/bmp"; break;
+				case IMAGETYPE_TIFF_II: $m= "image/tiff"; break;
+				case IMAGETYPE_TIFF_MM: $m= "image/tiff"; break;
+				case IMAGETYPE_JPC: $m= "image"; break;
+				case IMAGETYPE_JP2: $m= "image/jpeg2000"; break;
+				case IMAGETYPE_JPX: $m= "image/jpeg2000"; break;
+				case IMAGETYPE_JB2: $m= "image"; break;
+				case IMAGETYPE_SWC: $m= "application/x-shockwave-flash"; break;
+				case IMAGETYPE_IFF: $m= "image/vnd.xiff"; break;
+				case IMAGETYPE_WBMP: $m= "image/vnd.wap.wbmp"; break;
+				case IMAGETYPE_XBM: $m= "image/x-xbitmap"; break;
+			}
+
+			if ($m) {
+				wfDebug("$fname: image mime type of $file: $m\n");
+				return $m;
+			}
+			else $notAnImage= true;
+		} else {
+			// Also test DjVu
+			$deja = new DjVuImage( $file );
+			if( $deja->isValid() ) {
+				wfDebug("$fname: detected $file as image/vnd.djvu\n");
+				return 'image/vnd.djvu';
+			}
+		}
+
+		#if desired, look at extension as a fallback.
+		if ($useExt) {
+			$i = strrpos( $file, '.' );
+			$e= strtolower( $i ? substr( $file, $i + 1 ) : '' );
+
+			$m= $this->guessTypesForExtension($e);
+
+			#TODO: if $notAnImage is set, do not trust the file extension if
+			# the results is one of the image types that should have been recognized
+			# by getimagesize
+
+			if ($m) {
+				wfDebug("$fname: extension mime type of $file: $m\n");
+				return $m;
+			}
+		}
+
+		#unknown type
+		wfDebug("$fname: failed to guess mime type for $file!\n");
+		return "unknown/unknown";
+	}
+
+	/**
+	* Determine the media type code for a file, using its mime type, name and possibly
+	* its contents.
+	*
+	* This function relies on the findMediaType(), mapping extensions and mime
+	* types to media types.
+	*
+	* @todo analyse file if need be
+	* @todo look at multiple extension, separately and together.
+	*
+	* @param string $path full path to the image file, in case we have to look at the contents
+	*        (if null, only the mime type is used to determine the media type code).
+	* @param string $mime mime type. If null it will be guessed using guessMimeType.
+	*
+	* @return (int?string?) a value to be used with the MEDIATYPE_xxx constants.
+	*/
+	function getMediaType($path=NULL,$mime=NULL) {
+		if( !$mime && !$path ) return MEDIATYPE_UNKNOWN;
+
+		#if mime type is unknown, guess it
+		if( !$mime ) $mime= $this->guessMimeType($path,false);
+
+		#special code for ogg - detect if it's video (theora),
+		#else label it as sound.
+		if( $mime=="application/ogg" && file_exists($path) ) {
+
+			// Read a chunk of the file
+			$f = fopen( $path, "rt" );
+			if( !$f ) return MEDIATYPE_UNKNOWN;
+			$head = fread( $f, 256 );
+			fclose( $f );
+
+			$head= strtolower( $head );
+
+			#This is an UGLY HACK, file should be parsed correctly
+			if( strpos($head,'theora')!==false ) return MEDIATYPE_VIDEO;
+			elseif( strpos($head,'vorbis')!==false ) return MEDIATYPE_AUDIO;
+			elseif( strpos($head,'flac')!==false ) return MEDIATYPE_AUDIO;
+			elseif( strpos($head,'speex')!==false ) return MEDIATYPE_AUDIO;
+			else return MEDIATYPE_MULTIMEDIA;
+		}
+
+		#check for entry for full mime type
+		if( $mime ) {
+			$type= $this->findMediaType($mime);
+			if( $type!==MEDIATYPE_UNKNOWN ) return $type;
+		}
+
+		#check for entry for file extension
+		$e= NULL;
+		if( $path ) {
+			$i = strrpos( $path, '.' );
+			$e= strtolower( $i ? substr( $path, $i + 1 ) : '' );
+
+			#TODO: look at multi-extension if this fails, parse from full path
+
+			$type= $this->findMediaType('.'.$e);
+			if( $type!==MEDIATYPE_UNKNOWN ) return $type;
+		}
+
+		#check major mime type
+		if( $mime ) {
+			$i= strpos($mime,'/');
+			if( $i !== false ) {
+				$major= substr($mime,0,$i);
+				$type= $this->findMediaType($major);
+				if( $type!==MEDIATYPE_UNKNOWN ) return $type;
+			}
+		}
+
+		if( !$type ) $type= MEDIATYPE_UNKNOWN;
+
+		return $type;
+	}
+
+	/** returns a media code matching the given mime type or file extension.
+	* File extensions are represented by a string starting with a dot (.) to
+	* distinguish them from mime types.
+	*
+	* This funktion relies on the mapping defined by $this->mMediaTypes
+	* @access private
+	*/
+	function findMediaType($extMime) {
+
+		if (strpos($extMime,'.')===0) { #if it's an extension, look up the mime types
+			$m= $this->getTypesForExtension(substr($extMime,1));
+			if (!$m) return MEDIATYPE_UNKNOWN;
+
+			$m= explode(' ',$m);
+		}
+		else { #normalize mime type
+			if (isset($this->mMimeTypeAliases[$extMime])) {
+				$extMime= $this->mMimeTypeAliases[$extMime];
+			}
+
+			$m= array($extMime);
+		}
+
+		foreach ($m as $mime) {
+			foreach ($this->mMediaTypes as $type => $codes) {
+				if (in_array($mime,$codes,true)) return $type;
+			}
+		}
+
+		return MEDIATYPE_UNKNOWN;
+	}
+}
+
+?>