diff --git a/framework/yii/console/controllers/AssetController.php b/framework/yii/console/controllers/AssetController.php
index ca7896c..8e3de29 100644
--- a/framework/yii/console/controllers/AssetController.php
+++ b/framework/yii/console/controllers/AssetController.php
@@ -517,17 +517,77 @@ EOD
 	 */
 	public function combineCssFiles($inputFiles, $outputFile)
 	{
-		// todo: adjust url() references in CSS files
 		$content = '';
 		foreach ($inputFiles as $file) {
 			$content .= "/*** BEGIN FILE: $file ***/\n"
-				. file_get_contents($file)
+				. $this->adjustCssUrl(file_get_contents($file), dirname($file), dirname($outputFile))
 				. "/*** END FILE: $file ***/\n";
 		}
 		file_put_contents($outputFile, $content);
 	}
 
 	/**
+	 * Adjusts CSS content allowing URL references pointing to the original resources.
+	 * @param string $cssContent source CSS content.
+	 * @param string $inputFilePath input CSS file name.
+	 * @param string $outputFilePath output CSS file name.
+	 * @return string adjusted CSS content.
+	 */
+	protected function adjustCssUrl($cssContent, $inputFilePath, $outputFilePath)
+	{
+		$sharedPathParts = array();
+		$inputFilePathParts = explode('/', $inputFilePath);
+		$inputFilePathPartsCount = count($inputFilePathParts);
+		$outputFilePathParts = explode('/', $outputFilePath);
+		$outputFilePathPartsCount = count($outputFilePathParts);
+		for ($i =0; $i < $inputFilePathPartsCount && $i < $outputFilePathPartsCount; $i++) {
+			if ($inputFilePathParts[$i] == $outputFilePathParts[$i]) {
+				$sharedPathParts[] = $inputFilePathParts[$i];
+			} else {
+				break;
+			}
+		}
+		$sharedPath = implode('/', $sharedPathParts);
+
+		$inputFileRelativePath = trim(str_replace($sharedPath, '', $inputFilePath), '/');
+		$outputFileRelativePath = trim(str_replace($sharedPath, '', $outputFilePath), '/');
+		$inputFileRelativePathParts = explode('/', $inputFileRelativePath);
+		$outputFileRelativePathParts = explode('/', $outputFileRelativePath);
+
+		$callback = function($matches) use ($inputFileRelativePathParts, $outputFileRelativePathParts) {
+			$fullMatch = $matches[0];
+			$inputUrl = $matches[1];
+
+			if (preg_match('/https?:\/\//is', $inputUrl)) {
+				return $fullMatch;
+			}
+
+			$outputUrlParts = array_fill(0, count($outputFileRelativePathParts), '..');
+			$outputUrlParts = array_merge($outputUrlParts, $inputFileRelativePathParts);
+
+			if (strpos($inputUrl, '/') !== false) {
+				$inputUrlParts = explode('/', $inputUrl);
+				foreach ($inputUrlParts as $key => $inputUrlPart) {
+					if ($inputUrlPart == '..') {
+						array_pop($outputUrlParts);
+						unset($inputUrlParts[$key]);
+					}
+				}
+				$outputUrlParts[] = implode('/', $inputUrlParts);
+			} else {
+				$outputUrlParts[] = $inputUrl;
+			}
+			$outputUrl = implode('/', $outputUrlParts);
+
+			return str_replace($inputUrl, $outputUrl, $fullMatch);
+		};
+
+		$cssContent = preg_replace_callback('/url\(["\']?([^"]*)["\']?\)/is', $callback, $cssContent);
+
+		return $cssContent;
+	}
+
+	/**
 	 * Creates template of configuration file for [[actionCompress]].
 	 * @param string $configFile output file name.
 	 */
diff --git a/framework/yii/jui/Accordion.php b/framework/yii/jui/Accordion.php
index 1a83f28..f36c981 100644
--- a/framework/yii/jui/Accordion.php
+++ b/framework/yii/jui/Accordion.php
@@ -56,15 +56,38 @@ use yii\helpers\Html;
 class Accordion extends Widget
 {
 	/**
-	 * @var array list of collapsible sections.
+	 * @var array the HTML attributes for the widget container tag. The following special options are recognized:
+	 *
+	 * - tag: string, defaults to "div", the tag name of the container tag of this widget
+	 */
+	public $options = array();
+	/**
+	 * @var array list of collapsible items. Each item can be an array of the following structure:
+	 *
+	 * ~~~
+	 * array(
+	 *     'header' => 'Item header',
+	 *     'content' => 'Item content',
+	 *     // the HTML attributes of the item header container tag. This will overwrite "headerOptions".
+	 *     'headerOptions' => array(),
+	 *     // the HTML attributes of the item container tag. This will overwrite "itemOptions".
+	 *     'options' => array(),
+	 * )
+	 * ~~~
 	 */
 	public $items = array();
 	/**
-	 * @var array list of individual collabsible section default options.
+	 * @var array list of HTML attributes for the item container tags. This will be overwritten
+	 * by the "options" set in individual [[items]]. The following special options are recognized:
+	 *
+	 * - tag: string, defaults to "div", the tag name of the item container tags.
 	 */
 	public $itemOptions = array();
 	/**
-	 * @var array list of individual collabsible section header default options.
+	 * @var array list of HTML attributes for the item header container tags. This will be overwritten
+	 * by the "headerOptions" set in individual [[items]]. The following special options are recognized:
+	 *
+	 * - tag: string, defaults to "h3", the tag name of the item container tags.
 	 */
 	public $headerOptions = array();
 
@@ -83,7 +106,7 @@ class Accordion extends Widget
 	}
 
 	/**
-	 * Renders collapsible sections as specified on [[items]].
+	 * Renders collapsible items as specified on [[items]].
 	 * @return string the rendering result.
 	 * @throws InvalidConfigException.
 	 */
diff --git a/tests/unit/framework/console/controllers/AssetControllerTest.php b/tests/unit/framework/console/controllers/AssetControllerTest.php
index d792c9e..db6d2a7 100644
--- a/tests/unit/framework/console/controllers/AssetControllerTest.php
+++ b/tests/unit/framework/console/controllers/AssetControllerTest.php
@@ -169,6 +169,23 @@ class AssetControllerTest extends TestCase
 		}
 	}
 
+	/**
+	 * Invokes the asset controller method even if it is protected.
+	 * @param string $methodName name of the method to be invoked.
+	 * @param array $args method arguments.
+	 * @return mixed method invoke result.
+	 */
+	protected function invokeAssetControllerMethod($methodName, array $args = array())
+	{
+		$controller = $this->createAssetController();
+		$controllerClassReflection = new ReflectionClass(get_class($controller));
+		$methodReflection = $controllerClassReflection->getMethod($methodName);
+		$methodReflection->setAccessible(true);
+		$result = $methodReflection->invokeArgs($controller, $args);
+		$methodReflection->setAccessible(false);
+		return $result;
+	}
+
 	// Tests :
 
 	public function testActionTemplate()
@@ -237,4 +254,65 @@ class AssetControllerTest extends TestCase
 			$this->assertContains($content, $compressedJsFileContent, "Source of '{$name}' is missing in combined file!");
 		}
 	}
+
+	/**
+	 * Data provider for [[testAdjustCssUrl()]].
+	 * @return array test data.
+	 */
+	public function adjustCssUrlDataProvider()
+	{
+		return array(
+			array(
+				'.published-same-dir-class {background-image: url(published_same_dir.png);}',
+				'/test/base/path/assets/input',
+				'/test/base/path/assets/output',
+				'.published-same-dir-class {background-image: url(../input/published_same_dir.png);}',
+			),
+			array(
+				'.published-relative-dir-class {background-image: url(../img/published_relative_dir.png);}',
+				'/test/base/path/assets/input',
+				'/test/base/path/assets/output',
+				'.published-relative-dir-class {background-image: url(../img/published_relative_dir.png);}',
+			),
+			array(
+				'.static-same-dir-class {background-image: url(\'static_same_dir.png\');}',
+				'/test/base/path/css',
+				'/test/base/path/assets/output',
+				'.static-same-dir-class {background-image: url(\'../../css/static_same_dir.png\');}',
+			),
+			array(
+				'.static-relative-dir-class {background-image: url("../img/static_relative_dir.png");}',
+				'/test/base/path/css',
+				'/test/base/path/assets/output',
+				'.static-relative-dir-class {background-image: url("../../img/static_relative_dir.png");}',
+			),
+			array(
+				'.absolute-url-class {background-image: url(http://domain.com/img/image.gif);}',
+				'/test/base/path/assets/input',
+				'/test/base/path/assets/output',
+				'.absolute-url-class {background-image: url(http://domain.com/img/image.gif);}',
+			),
+			array(
+				'.absolute-url-secure-class {background-image: url(https://secure.domain.com/img/image.gif);}',
+				'/test/base/path/assets/input',
+				'/test/base/path/assets/output',
+				'.absolute-url-secure-class {background-image: url(https://secure.domain.com/img/image.gif);}',
+			),
+		);
+	}
+
+	/**
+	 * @dataProvider adjustCssUrlDataProvider
+	 *
+	 * @param $cssContent
+	 * @param $inputFilePath
+	 * @param $outputFilePath
+	 * @param $expectedCssContent
+	 */
+	public function testAdjustCssUrl($cssContent, $inputFilePath, $outputFilePath, $expectedCssContent)
+	{
+		$adjustedCssContent = $this->invokeAssetControllerMethod('adjustCssUrl', array($cssContent, $inputFilePath, $outputFilePath));
+
+		$this->assertEquals($expectedCssContent, $adjustedCssContent, 'Unable to adjust CSS correctly!');
+	}
 }