Fixed typo in DocBlock

Router::defaultRouteClass will return the current routeClass if null is
passed
Router::connect and Router::defaultRouteClass both validate the routeClass
now using Router::_validateRouteClass

lib/Cake/Routing/Router.php

@@ -160,14 +160,33 @@ class Router {
     protected static $_routeClass = 'CakeRoute';
 
 /**
- * Set the default rotue class to use
+ * Set the default route class to use or return the current one
  *
- * @param sting $routeClass to set as default
- * @return void
+ * @param string $routeClass to set as default
+ * @return mixed void|string
+ * @throws RouterException
  */
-    public static function defaultRouteClass($routeClass) {
-        self::$_routeClass = $routeClass;
-    }
+	public static function defaultRouteClass($routeClass = null) {
+		if (is_null($routeClass)) {
+			return self::$_routeClass;
+		}
+
+		self::$_routeClass = self::_validateRouteClass($routeClass);
+	}
+
+/**
+ * Validates that the passed route class exists and is a subclass of CakeRoute
+ *
+ * @param $routeClass
+ * @return string
+ * @throws RouterException
+ */
+	protected static function _validateRouteClass($routeClass) {
+		if (!class_exists($routeClass) || !is_subclass_of($routeClass, 'CakeRoute')) {
+			throw new RouterException(__d('cake_dev', 'Route classes must extend CakeRoute'));
+		}
+		return $routeClass;
+	}
 
 /**
  * Sets the Routing prefixes.
@@ -278,14 +297,11 @@ class Router {
 		}
 		$routeClass = self::$_routeClass;
 		if (isset($options['routeClass'])) {
-			$routeClass = $options['routeClass'];
-			if (!is_subclass_of($routeClass, 'CakeRoute')) {
-				throw new RouterException(__d('cake_dev', 'Route classes must extend CakeRoute'));
-			}
+			$routeClass = self::_validateRouteClass($options['routeClass']);
 			unset($options['routeClass']);
-			if ($routeClass == 'RedirectRoute' && isset($defaults['redirect'])) {
-				$defaults = $defaults['redirect'];
-			}
+		}
+		if ($routeClass == 'RedirectRoute' && isset($defaults['redirect'])) {
+			$defaults = $defaults['redirect'];
 		}
 		self::$routes[] = new $routeClass($route, $defaults, $options);
 		return self::$routes;

lib/Cake/Test/Case/Routing/RouterTest.php

@@ -2519,4 +2519,48 @@ class RouterTest extends CakeTestCase {
 		$this->assertInstanceOf('TestDefaultRouteClass', $result[0]);
 	}
 
+/**
+ * Test getting the default route class
+ *
+ * @return void
+ */
+	public function testDefaultRouteClassGetter() {
+		$routeClass = 'TestDefaultRouteClass';
+		Router::defaultRouteClass($routeClass);
+
+		$this->assertEqual($routeClass, Router::defaultRouteClass());
+		$this->assertEqual($routeClass, Router::defaultRouteClass(null));
+	}
+
+/**
+ * Test that route classes must extend CakeRoute
+ *
+ * @expectedException RouterException
+ * @return void
+ */
+	public function testDefaultRouteException() {
+		Router::defaultRouteClass('');
+		Router::connect('/:controller', array());
+	}
+
+/**
+ * Test that route classes must extend CakeRoute
+ *
+ * @expectedException RouterException
+ * @return void
+ */
+	public function testSettingInvalidDefaultRouteException() {
+		Router::defaultRouteClass('Object');
+	}
+
+/**
+ * Test that class must exist
+ *
+ * @expectedException RouterException
+ * @return void
+ */
+	public function testSettingNonExistentDefaultRouteException() {
+		Router::defaultRouteClass('NonExistentClass');
+	}
+
 }