Index: class.t3lib_div.php
===================================================================
--- class.t3lib_div.php	(revision 5928)
+++ class.t3lib_div.php	(working copy)
@@ -284,6 +284,8 @@
 	const HTTP_STATUS_504 = 'HTTP/1.1 504 Gateway Timeout';
 	const HTTP_STATUS_505 = 'HTTP/1.1 505 Version Not Supported';
 
+		// holds references of singletons
+	protected static $instances = array();
 
 
 	/*************************
@@ -4903,6 +4905,31 @@
 	}
 
 	/**
+	 * Adds or replaces the given object in the internal instances collection
+	 * After that, t3lib_div::instance() will return the specified $isntance for
+	 * $className
+	 *
+	 * @param	string		Class name to instantiate
+	 * @param	string		Class name to instantiate
+	 * @return	void
+	 */
+	public static function registerInstance($className, $instance) {
+		self::$instances[$className] = $instance;
+	}
+
+	/**
+	 * Removes the specified class from the internal instances collection
+	 *
+	 * @param	string		Class name to instantiate
+	 * @return	void
+	 */
+	public static function unregisterInstance($className) {
+		if (isset(self::$instances[$className])) {
+			unset(self::$instances[$className]);
+		}
+	}
+
+	/**
 	 * Creates an instance of a class taking into account the class-extensions
 	 * API of TYPO3. USE THIS method instead of the PHP "new" keyword.
 	 * Eg. "$obj = new myclass;" should be "$obj = t3lib_div::makeInstance("myclass")" instead!
@@ -4913,15 +4940,12 @@
 	 * @return	object		A reference to the object
 	 */
 	public static function &makeInstance($className) {
-			// holds references of singletons
-		static $instances = array();
-
 			// Get final classname
 		$className = self::getClassName($className);
 
-		if (isset($instances[$className])) {
+		if (isset(self::$instances[$className])) {
 				// it's a singleton, get the existing instance
-			$instance = $instances[$className];
+			$instance = self::$instances[$className];
 		} else {
 			if (func_num_args() > 1) {
 					// getting the constructor arguments by removing this
@@ -4937,7 +4961,7 @@
 
 			if ($instance instanceof t3lib_Singleton) {
 					// it's a singleton, save the instance for later reuse
-				$instances[$className] = $instance;
+				self::$instances[$className] = $instance;
 			}
 		}