Index: t3lib/config_default.php
===================================================================
--- t3lib/config_default.php	(revision 4395)
+++ t3lib/config_default.php	(working copy)
@@ -195,7 +195,7 @@
 		'forceCharset' => '',					// String. Normally the charset of the backend users language selection is used. If you set this value to a charset found in t3lib/csconvtbl/ (or "utf-8") the backend (and database) will ALWAYS use this charset. Always use a lowercase value.
 		'installToolPassword' => '',			// String. This is the md5-hashed password for the Install Tool. Set this to '' and access will be totally denied. PLEASE consider to externally password protect the typo3/install/ folder, eg. with a .htaccess file.
 		'trackBeUser' => 0,						// Boolean. If set, every invokation of a backend script is logged in sys_trackbeuser. This is used to get a view of the backend users behaviour. Mostly for debugging, support and user interaction analysis. Requires 'beuser_tracking' extension.
- 		'defaultUserTSconfig' => 'options.shortcutFrame=1',			// String. Enter lines of default backend user/group TSconfig.
+		'defaultUserTSconfig' => 'options.shortcutFrame=1',			// String. Enter lines of default backend user/group TSconfig.
 		'defaultPageTSconfig' => '',			// Enter lines of default Page TSconfig.
 		'defaultPermissions' => array (			// Default permissions set for new pages in t3lib/tce_main.php. Keys are 'show,edit,delete,new,editcontent'. Enter as comma-list
 //			'user' => '',						// default in tce_main is 'show,edit,delete,new,editcontent'. If this is set (uncomment), this value is used instead.
@@ -230,6 +230,7 @@
 		'compactFlexFormXML' => 0,				// If set, the flexform XML will not contain indentation spaces making XML more compact
 		'explicitConfirmationOfTranslation' => FALSE,	// If set, the the diff-data of localized records is not saved automatically when updated by requires that a translator clicks the special finish_translation/save/close button that becomes available.
 		'elementVersioningOnly' => FALSE,		// If true, only element versioning is allowed in the backend. This is recommended for new installations of TYPO3 4.2+ since "page" and "branch" versioning types are known for the drawbacks of loosing ids and "element" type versions supports moving now.
+		'disableCompressedLibs' => FALSE,		// If true, the function loadJavascriptLib will not load the compressed library file
 		'AJAX' => array(				// array of key-value pairs for a unified use of AJAX calls in the TYPO3 backend. Keys are the unique ajaxIDs where the value will be resolved to call a method in an object. See ajax.php and the classes/class.typo3ajax.php for more information.
 			'SC_alt_db_navframe::expandCollapse'                => 'typo3/alt_db_navframe.php:SC_alt_db_navframe->ajaxExpandCollapse',
 			'SC_alt_file_navframe::expandCollapse'              => 'typo3/alt_file_navframe.php:SC_alt_file_navframe->ajaxExpandCollapse',
Index: typo3/template.php
===================================================================
--- typo3/template.php	(revision 4395)
+++ typo3/template.php	(working copy)
@@ -1285,9 +1285,16 @@
 	 * 				like "contrib/prototype/prototype.js" to load it
 	 * @return	void
 	 */
-	function loadJavascriptLib($lib)	{
-		if (!isset($this->JScodeLibArray[$lib]))	{
-			$this->JScodeLibArray[$lib] = '<script type="text/javascript" src="'.$this->backPath.$lib.'"></script>';
+	function loadJavascriptLib($lib) {
+		if (!isset($this->JScodeLibArray[$lib])) {    
+			if (!$GLOBALS['TYPO3_CONF_VARS']['BE']['disableCompressedLibs']) {
+				// if file exist as compressed version (filename.compressed.js), then include it
+				if (substr($lib, -3) == '.js' && is_file($this->backPath . substr($lib, 0, -3) . '.compressed.js')) {
+					$lib = substr($lib, 0, -3) . '.compressed.js';   debug(array(substr($lib, -3), substr($lib, 0, -3) . '.compressed.js'));       
+				}
+			}
+			
+			$this->JScodeLibArray[$lib] = '<script type="text/javascript" src="' . $this->backPath . $lib . '"></script>';
 		}
 	}