Index: Tests/MVC/Controller/AbstractController_testcase.php
===================================================================
--- Tests/MVC/Controller/AbstractController_testcase.php	(revision 2599)
+++ Tests/MVC/Controller/AbstractController_testcase.php	(working copy)
@@ -145,7 +145,22 @@
 		
 		$this->assertEquals($expectedResult, $actualResult);
 	}
+	
+	/**
+	 * @test
+	 */
+	public function theBaseUriIsNotAddedIfExternalURI() {
+		$mockRequest = $this->getMock('Tx_Extbase_MVC_Web_Request');
+		$mockRequest->expects($this->any())->method('getBaseURI')->will($this->returnValue('http://www.example.com/foo/'));
 
+		$controller = $this->getMock($this->buildAccessibleProxy('Tx_Extbase_MVC_Controller_AbstractController'), array('dummy'), array(), '', FALSE);
+		$controller->_set('request', $mockRequest);
+		$actualResult = $controller->_call('addBaseUriIfNecessary', 'http://www.anotherexample.com/foo/bar/baz/boom.html');
+		$expectedResult = 'http://www.anotherexample.com/foo/bar/baz/boom.html';
+		
+		$this->assertEquals($expectedResult, $actualResult);
+	}
+
 	/**
 	 * @test
 	 * @expectedException Tx_Extbase_MVC_Exception_StopAction
Index: Classes/MVC/Controller/AbstractController.php
===================================================================
--- Classes/MVC/Controller/AbstractController.php	(revision 2599)
+++ Classes/MVC/Controller/AbstractController.php	(working copy)
@@ -336,7 +336,7 @@
 	 */
 	protected function addBaseUriIfNecessary($uri) {
 		$baseUri = $this->request->getBaseURI();
-		if(stripos($uri, $baseUri) !== 0) {
+		if(stripos($uri, 'http://') !== 0 && stripos($uri, 'https://') !== 0) {
 			$uri = $baseUri . (string)$uri;
 		}
 		return $uri;